0.8.4.1
[sbcl.git] / src / runtime / gencgc.c
index 6130e4f..b6917ab 100644 (file)
@@ -26,6 +26,7 @@
 
 #include <stdio.h>
 #include <signal.h>
+#include <errno.h>
 #include "runtime.h"
 #include "sbcl.h"
 #include "os.h"
 #include "lispregs.h"
 #include "arch.h"
 #include "gc.h"
-#include "gencgc.h"
+#include "gc-internal.h"
+#include "thread.h"
+#include "genesis/vector.h"
+#include "genesis/weak-pointer.h"
+#include "genesis/simple-fun.h"
+
+#ifdef LISP_FEATURE_SB_THREAD
+#include <sys/ptrace.h>
+#include <linux/user.h>                /* threading is presently linux-only */
+#endif
 
-/* a function defined externally in assembly language, called from
- * this file */
+/* assembly language stub that executes trap_PendingInterrupt */
 void do_pending_interrupt(void);
+
+/* forward declarations */
+int gc_find_freeish_pages(int *restart_page_ptr, int nbytes, int unboxed, struct alloc_region *alloc_region);
+void  gc_set_region_empty(struct alloc_region *region);
+void gc_alloc_update_all_page_tables(void);
+static void  gencgc_pickup_dynamic(void);
+boolean interrupt_maybe_gc_int(int, siginfo_t *, void *);
+
 \f
 /*
  * GC parameters
  */
 
 /* the number of actual generations. (The number of 'struct
- * generation' objects is one more than this, because one serves as
- * scratch when GC'ing.) */
+ * generation' objects is one more than this, because one object
+ * serves as scratch when GC'ing.) */
 #define NUM_GENERATIONS 6
 
 /* Should we use page protection to help avoid the scavenging of pages
@@ -71,44 +88,12 @@ boolean gencgc_unmap_zero = 1;
 
 /* the minimum size (in bytes) for a large object*/
 unsigned large_object_size = 4 * 4096;
-
-/* Should we filter stack/register pointers? This substantially reduces the
- * number of invalid pointers accepted.
- *
- * FIXME: This is basically constant=1. It will probably degrade
- * interrupt safety during object initialization. But I don't think we
- * should do without it -- the possibility of the GC being too
- * conservative and hence running out of memory is also. Perhaps the
- * interrupt safety issue could be fixed by making the initialization
- * code do WITHOUT-GCING or WITHOUT-INTERRUPTS until the appropriate
- * type bits have been set. (That might be necessary anyway, in order
- * to keep interrupt code's allocation operations from stepping on the
- * interrupted code's allocations.) Or perhaps it could be fixed by
- * making sure that uninitialized memory is zero, reserving the
- * all-zero case for uninitialized memory, and making the
- * is-it-possibly-a-valid-pointer code check for all-zero and return
- * true in that case. Then after either fix, we could get rid of this
- * variable and simply hardwire the system always to do pointer
- * filtering. */
-boolean enable_pointer_filter = 1;
 \f
 /*
  * debugging
  */
 
-#define gc_abort() lose("GC invariant lost, file \"%s\", line %d", \
-                       __FILE__, __LINE__)
 
-/* FIXME: In CMU CL, this was "#if 0" with no explanation. Find out
- * how much it costs to make it "#if 1". If it's not too expensive,
- * keep it. */
-#if 1
-#define gc_assert(ex) do { \
-       if (!(ex)) gc_abort(); \
-} while (0)
-#else
-#define gc_assert(ex)
-#endif
 
 /* the verbosity level. All non-error messages are disabled at level 0;
  * and only a few rare messages are printed at level 1. */
@@ -151,16 +136,19 @@ boolean gencgc_zero_check_during_free_heap = 0;
 
 /* the total bytes allocated. These are seen by Lisp DYNAMIC-USAGE. */
 unsigned long bytes_allocated = 0;
-static unsigned long auto_gc_trigger = 0;
+extern unsigned long bytes_consed_between_gcs; /* gc-common.c */
+unsigned long auto_gc_trigger = 0;
 
 /* the source and destination generations. These are set before a GC starts
  * scavenging. */
-static int from_space;
-static int new_space;
+int from_space;
+int new_space;
+
 
 /* FIXME: It would be nice to use this symbolic constant instead of
  * bare 4096 almost everywhere. We could also use an assertion that
  * it's equal to getpagesize(). */
+
 #define PAGE_BYTES 4096
 
 /* An array of page structures is statically allocated.
@@ -172,9 +160,10 @@ struct page page_table[NUM_PAGES];
  * is needed. */
 static void *heap_base = NULL;
 
+
 /* Calculate the start address for the given page number. */
-inline void
-*page_address(int page_num)
+inline void *
+page_address(int page_num)
 {
     return (heap_base + (page_num * 4096));
 }
@@ -198,10 +187,10 @@ find_page_index(void *addr)
 /* a structure to hold the state of a generation */
 struct generation {
 
-    /* the first page that gc_alloc checks on its next call */
+    /* the first page that gc_alloc() checks on its next call */
     int alloc_start_page;
 
-    /* the first page that gc_alloc_unboxed checks on its next call */
+    /* the first page that gc_alloc_unboxed() checks on its next call */
     int alloc_unboxed_start_page;
 
     /* the first page that gc_alloc_large (boxed) considers on its next
@@ -241,11 +230,15 @@ struct generation {
      * added, in which case a GC could be a waste of time */
     double min_av_mem_age;
 };
+/* the number of actual generations. (The number of 'struct
+ * generation' objects is one more than this, because one object
+ * serves as scratch when GC'ing.) */
+#define NUM_GENERATIONS 6
 
 /* an array of generation structures. There needs to be one more
  * generation structure than actual generations as the oldest
  * generation is temporarily raised then lowered. */
-static struct generation generations[NUM_GENERATIONS+1];
+struct generation generations[NUM_GENERATIONS+1];
 
 /* the oldest generation that is will currently be GCed by default.
  * Valid values are: 0, 1, ... (NUM_GENERATIONS-1)
@@ -266,7 +259,16 @@ unsigned int  gencgc_oldest_gen_to_gc = NUM_GENERATIONS-1;
  * search of the heap. XX Gencgc obviously needs to be better
  * integrated with the Lisp code. */
 static int  last_free_page;
-static int  last_used_page = 0;
+\f
+/* This lock is to prevent multiple threads from simultaneously
+ * allocating new regions which overlap each other.  Note that the
+ * majority of GC is single-threaded, but alloc() may be called from
+ * >1 thread at a time and must be thread-safe.  This lock must be
+ * seized before all accesses to generations[] or to parts of
+ * page_table[] that other threads may want to see */
+
+static lispobj free_pages_lock=0;
+
 \f
 /*
  * miscellaneous heap functions
@@ -308,22 +310,21 @@ count_dont_move_pages(void)
 {
     int i;
     int count = 0;
-
-    for (i = 0; i < last_free_page; i++)
-       if ((page_table[i].allocated != 0)
-           && (page_table[i].dont_move != 0))
-           count++;
+    for (i = 0; i < last_free_page; i++) {
+       if ((page_table[i].allocated != 0) && (page_table[i].dont_move != 0)) {
+           ++count;
+       }
+    }
     return count;
 }
 
 /* Work through the pages and add up the number of bytes used for the
  * given generation. */
 static int
-generation_bytes_allocated (int gen)
+count_generation_bytes_allocated (int gen)
 {
     int i;
     int result = 0;
-
     for (i = 0; i < last_free_page; i++) {
        if ((page_table[i].allocated != 0) && (page_table[i].gen == gen))
            result += page_table[i].bytes_used;
@@ -343,6 +344,8 @@ gen_av_mem_age(int gen)
        / ((double)generations[gen].bytes_allocated);
 }
 
+void fpu_save(int *);          /* defined in x86-assem.S */
+void fpu_restore(int *);       /* defined in x86-assem.S */
 /* The verbose argument controls how much to print: 0 for normal
  * level of detail; 1 for debugging. */
 static void
@@ -377,7 +380,7 @@ print_generation_stats(int verbose) /* FIXME: should take FILE argument */
 
                /* Count the number of boxed pages within the given
                 * generation. */
-               if (page_table[j].allocated == BOXED_PAGE) {
+               if (page_table[j].allocated & BOXED_PAGE) {
                    if (page_table[j].large_object)
                        large_boxed_cnt++;
                    else
@@ -386,7 +389,7 @@ print_generation_stats(int verbose) /* FIXME: should take FILE argument */
 
                /* Count the number of unboxed pages within the given
                 * generation. */
-               if (page_table[j].allocated == UNBOXED_PAGE) {
+               if (page_table[j].allocated & UNBOXED_PAGE) {
                    if (page_table[j].large_object)
                        large_unboxed_cnt++;
                    else
@@ -395,7 +398,7 @@ print_generation_stats(int verbose) /* FIXME: should take FILE argument */
            }
 
        gc_assert(generations[i].bytes_allocated
-                 == generation_bytes_allocated(i));
+                 == count_generation_bytes_allocated(i));
        fprintf(stderr,
                "   %8d: %5d %5d %5d %5d %8d %5d %8d %4d %3d %7.4f\n",
                i,
@@ -468,10 +471,6 @@ print_generation_stats(int verbose) /* FIXME: should take FILE argument */
 struct alloc_region boxed_region;
 struct alloc_region unboxed_region;
 
-/* XX hack. Current Lisp code uses the following. Need copying in/out. */
-void *current_region_free_pointer;
-void *current_region_end_addr;
-
 /* The generation currently being allocated to. */
 static int gc_alloc_generation;
 
@@ -482,7 +481,7 @@ static int gc_alloc_generation;
  * keeps the allocation contiguous when scavenging the newspace.
  *
  * The alloc_region should have been closed by a call to
- * gc_alloc_update_page_tables, and will thus be in an empty state.
+ * gc_alloc_update_page_tables(), and will thus be in an empty state.
  *
  * To assist the scavenging functions write-protected pages are not
  * used. Free pages should not be write-protected.
@@ -503,10 +502,7 @@ gc_alloc_new_region(int nbytes, int unboxed, struct alloc_region *alloc_region)
 {
     int first_page;
     int last_page;
-    int region_size;
-    int restart_page;
     int bytes_found;
-    int num_pages;
     int i;
 
     /*
@@ -519,100 +515,18 @@ gc_alloc_new_region(int nbytes, int unboxed, struct alloc_region *alloc_region)
     gc_assert((alloc_region->first_page == 0)
              && (alloc_region->last_page == -1)
              && (alloc_region->free_pointer == alloc_region->end_addr));
-
+    get_spinlock(&free_pages_lock,(int) alloc_region);
     if (unboxed) {
-       restart_page =
+       first_page =
            generations[gc_alloc_generation].alloc_unboxed_start_page;
     } else {
-       restart_page =
+       first_page =
            generations[gc_alloc_generation].alloc_start_page;
     }
-
-    /* Search for a contiguous free region of at least nbytes with the
-     * given properties: boxed/unboxed, generation. */
-    do {
-       first_page = restart_page;
-
-       /* First search for a page with at least 32 bytes free, which is
-        * not write-protected, and which is not marked dont_move. */
-       while ((first_page < NUM_PAGES)
-              && (page_table[first_page].allocated != FREE_PAGE) /* not free page */
-              && ((unboxed &&
-                   (page_table[first_page].allocated != UNBOXED_PAGE))
-                  || (!unboxed &&
-                      (page_table[first_page].allocated != BOXED_PAGE))
-                  || (page_table[first_page].large_object != 0)
-                  || (page_table[first_page].gen != gc_alloc_generation)
-                  || (page_table[first_page].bytes_used >= (4096-32))
-                  || (page_table[first_page].write_protected != 0)
-                  || (page_table[first_page].dont_move != 0)))
-           first_page++;
-       /* Check for a failure. */
-       if (first_page >= NUM_PAGES) {
-           fprintf(stderr,
-                   "Argh! gc_alloc_new_region failed on first_page, nbytes=%d.\n",
-                   nbytes);
-           print_generation_stats(1);
-           lose(NULL);
-       }
-
-       gc_assert(page_table[first_page].write_protected == 0);
-
-       /*
-       FSHOW((stderr,
-              "/first_page=%d bytes_used=%d\n",
-              first_page, page_table[first_page].bytes_used));
-       */
-
-       /* Now search forward to calculate the available region size. It
-        * tries to keeps going until nbytes are found and the number of
-        * pages is greater than some level. This helps keep down the
-        * number of pages in a region. */
-       last_page = first_page;
-       bytes_found = 4096 - page_table[first_page].bytes_used;
-       num_pages = 1;
-       while (((bytes_found < nbytes) || (num_pages < 2))
-              && (last_page < (NUM_PAGES-1))
-              && (page_table[last_page+1].allocated == FREE_PAGE)) {
-           last_page++;
-           num_pages++;
-           bytes_found += 4096;
-           gc_assert(page_table[last_page].write_protected == 0);
-       }
-
-       region_size = (4096 - page_table[first_page].bytes_used)
+    last_page=gc_find_freeish_pages(&first_page,nbytes,unboxed,alloc_region);
+    bytes_found=(4096 - page_table[first_page].bytes_used)
            + 4096*(last_page-first_page);
 
-       gc_assert(bytes_found == region_size);
-
-       /*
-       FSHOW((stderr,
-              "/last_page=%d bytes_found=%d num_pages=%d\n",
-              last_page, bytes_found, num_pages));
-       */
-
-       restart_page = last_page + 1;
-    } while ((restart_page < NUM_PAGES) && (bytes_found < nbytes));
-
-    /* Check for a failure. */
-    if ((restart_page >= NUM_PAGES) && (bytes_found < nbytes)) {
-       fprintf(stderr,
-               "Argh! gc_alloc_new_region failed on restart_page, nbytes=%d.\n",
-               nbytes);
-       print_generation_stats(1);
-       lose(NULL);
-    }
-
-    /*
-    FSHOW((stderr,
-          "/gc_alloc_new_region gen %d: %d bytes: pages %d to %d: addr=%x\n",
-          gc_alloc_generation,
-          bytes_found,
-          first_page,
-          last_page,
-          page_address(first_page)));
-    */
-
     /* Set up the alloc_region. */
     alloc_region->first_page = first_page;
     alloc_region->last_page = last_page;
@@ -621,20 +535,6 @@ gc_alloc_new_region(int nbytes, int unboxed, struct alloc_region *alloc_region)
     alloc_region->free_pointer = alloc_region->start_addr;
     alloc_region->end_addr = alloc_region->start_addr + bytes_found;
 
-    if (gencgc_zero_check) {
-       int *p;
-       for (p = (int *)alloc_region->start_addr;
-           p < (int *)alloc_region->end_addr; p++) {
-           if (*p != 0) {
-               /* KLUDGE: It would be nice to use %lx and explicit casts
-                * (long) in code like this, so that it is less likely to
-                * break randomly when running on a machine with different
-                * word sizes. -- WHN 19991129 */
-               lose("The new region at %x is not zero.", p);
-           }
-       }
-    }
-
     /* Set up the pages. */
 
     /* The first page may have already been in use. */
@@ -652,6 +552,8 @@ gc_alloc_new_region(int nbytes, int unboxed, struct alloc_region *alloc_region)
        gc_assert(page_table[first_page].allocated == UNBOXED_PAGE);
     else
        gc_assert(page_table[first_page].allocated == BOXED_PAGE);
+    page_table[first_page].allocated |= OPEN_REGION_PAGE; 
+
     gc_assert(page_table[first_page].gen == gc_alloc_generation);
     gc_assert(page_table[first_page].large_object == 0);
 
@@ -666,18 +568,34 @@ gc_alloc_new_region(int nbytes, int unboxed, struct alloc_region *alloc_region)
         * broken before!) */
        page_table[i].first_object_offset =
            alloc_region->start_addr - page_address(i);
+       page_table[i].allocated |= OPEN_REGION_PAGE ;
     }
-
     /* Bump up last_free_page. */
     if (last_page+1 > last_free_page) {
        last_free_page = last_page+1;
        SetSymbolValue(ALLOCATION_POINTER,
-                      (lispobj)(((char *)heap_base) + last_free_page*4096));
-       if (last_page+1 > last_used_page)
-           last_used_page = last_page+1;
+                      (lispobj)(((char *)heap_base) + last_free_page*4096),
+                      0);
+    }
+    release_spinlock(&free_pages_lock);
+    
+    /* we can do this after releasing free_pages_lock */
+    if (gencgc_zero_check) {
+       int *p;
+       for (p = (int *)alloc_region->start_addr;
+            p < (int *)alloc_region->end_addr; p++) {
+           if (*p != 0) {
+               /* KLUDGE: It would be nice to use %lx and explicit casts
+                * (long) in code like this, so that it is less likely to
+                * break randomly when running on a machine with different
+                * word sizes. -- WHN 19991129 */
+               lose("The new region at %x is not zero.", p);
+           }
     }
 }
 
+}
+
 /* If the record_new_objects flag is 2 then all new regions created
  * are recorded.
  *
@@ -750,12 +668,11 @@ add_new_area(int first_page, int offset, int size)
                   (*new_areas)[i].size,
                   first_page,
                   offset,
-                  size));*/
+                   size);*/
            (*new_areas)[i].size += size;
            return;
        }
     }
-    /*FSHOW((stderr, "/add_new_area S1 %d %d %d\n", i, c, new_area_start));*/
 
     (*new_areas)[new_areas_index].page = first_page;
     (*new_areas)[new_areas_index].offset = offset;
@@ -770,7 +687,7 @@ add_new_area(int first_page, int offset, int size)
        max_new_areas = new_areas_index;
 }
 
-/* Update the tables for the alloc_region. The region maybe added to
+/* Update the tables for the alloc_region. The region may be added to
  * the new_areas.
  *
  * When done the alloc_region is set up so that the next quick alloc
@@ -790,7 +707,7 @@ gc_alloc_update_page_tables(int unboxed, struct alloc_region *alloc_region)
 
     /*
     FSHOW((stderr,
-          "/gc_alloc_update_page_tables to gen %d:\n",
+          "/gc_alloc_update_page_tables() to gen %d:\n",
           gc_alloc_generation));
     */
 
@@ -802,8 +719,9 @@ gc_alloc_update_page_tables(int unboxed, struct alloc_region *alloc_region)
 
     next_page = first_page+1;
 
-    /* Skip if no bytes were allocated. */
+    get_spinlock(&free_pages_lock,(int) alloc_region);
     if (alloc_region->free_pointer != alloc_region->start_addr) {
+       /* some bytes were allocated in the region */
        orig_first_page_bytes_used = page_table[first_page].bytes_used;
 
        gc_assert(alloc_region->start_addr == (page_address(first_page) + page_table[first_page].bytes_used));
@@ -816,6 +734,7 @@ gc_alloc_update_page_tables(int unboxed, struct alloc_region *alloc_region)
         * first_object_offset. */
        if (page_table[first_page].bytes_used == 0)
            gc_assert(page_table[first_page].first_object_offset == 0);
+       page_table[first_page].allocated &= ~(OPEN_REGION_PAGE);
 
        if (unboxed)
            gc_assert(page_table[first_page].allocated == UNBOXED_PAGE);
@@ -841,6 +760,7 @@ gc_alloc_update_page_tables(int unboxed, struct alloc_region *alloc_region)
         * first_object_offset pointer to the start of the region, and set
         * the bytes_used. */
        while (more) {
+           page_table[next_page].allocated &= ~(OPEN_REGION_PAGE);
            if (unboxed)
                gc_assert(page_table[next_page].allocated == UNBOXED_PAGE);
            else
@@ -892,6 +812,7 @@ gc_alloc_update_page_tables(int unboxed, struct alloc_region *alloc_region)
     } else {
        /* There are no bytes allocated. Unallocate the first_page if
         * there are 0 bytes_used. */
+       page_table[first_page].allocated &= ~(OPEN_REGION_PAGE);
        if (page_table[first_page].bytes_used == 0)
            page_table[first_page].allocated = FREE_PAGE;
     }
@@ -902,27 +823,19 @@ gc_alloc_update_page_tables(int unboxed, struct alloc_region *alloc_region)
        page_table[next_page].allocated = FREE_PAGE;
        next_page++;
     }
-
-    /* Reset the alloc_region. */
-    alloc_region->first_page = 0;
-    alloc_region->last_page = -1;
-    alloc_region->start_addr = page_address(0);
-    alloc_region->free_pointer = page_address(0);
-    alloc_region->end_addr = page_address(0);
+    release_spinlock(&free_pages_lock);
+    /* alloc_region is per-thread, we're ok to do this unlocked */
+    gc_set_region_empty(alloc_region);
 }
 
 static inline void *gc_quick_alloc(int nbytes);
 
 /* Allocate a possibly large object. */
-static void
-*gc_alloc_large(int nbytes, int unboxed, struct alloc_region *alloc_region)
+void *
+gc_alloc_large(int nbytes, int unboxed, struct alloc_region *alloc_region)
 {
     int first_page;
     int last_page;
-    int region_size;
-    int restart_page;
-    int bytes_found;
-    int num_pages;
     int orig_first_page_bytes_used;
     int byte_cnt;
     int more;
@@ -937,115 +850,35 @@ static void
 
     /*
     FSHOW((stderr,
-          "/gc_alloc_large for %d bytes from gen %d\n",
+          "/gc_alloc_large() for %d bytes from gen %d\n",
           nbytes, gc_alloc_generation));
     */
 
     /* If the object is small, and there is room in the current region
-       then allocation it in the current region. */
+       then allocate it in the current region. */
     if (!large
        && ((alloc_region->end_addr-alloc_region->free_pointer) >= nbytes))
        return gc_quick_alloc(nbytes);
 
-    /* Search for a contiguous free region of at least nbytes. If it's a
-       large object then align it on a page boundary by searching for a
-       free page. */
-
     /* To allow the allocation of small objects without the danger of
        using a page in the current boxed region, the search starts after
        the current boxed free region. XX could probably keep a page
        index ahead of the current region and bumped up here to save a
        lot of re-scanning. */
-    if (unboxed)
-       restart_page = generations[gc_alloc_generation].alloc_large_unboxed_start_page;
-    else
-       restart_page = generations[gc_alloc_generation].alloc_large_start_page;
-    if (restart_page <= alloc_region->last_page)
-       restart_page = alloc_region->last_page+1;
-
-    do {
-       first_page = restart_page;
-
-       if (large)
-           while ((first_page < NUM_PAGES)
-                  && (page_table[first_page].allocated != FREE_PAGE))
-               first_page++;
-       else
-           while ((first_page < NUM_PAGES)
-                  && (page_table[first_page].allocated != FREE_PAGE)
-                  && ((unboxed &&
-                       (page_table[first_page].allocated != UNBOXED_PAGE))
-                      || (!unboxed &&
-                          (page_table[first_page].allocated != BOXED_PAGE))
-                      || (page_table[first_page].large_object != 0)
-                      || (page_table[first_page].gen != gc_alloc_generation)
-                      || (page_table[first_page].bytes_used >= (4096-32))
-                      || (page_table[first_page].write_protected != 0)
-                      || (page_table[first_page].dont_move != 0)))
-               first_page++;
-
-       if (first_page >= NUM_PAGES) {
-           fprintf(stderr,
-                   "Argh! gc_alloc_large failed (first_page), nbytes=%d.\n",
-                   nbytes);
-           print_generation_stats(1);
-           lose(NULL);
-       }
-
-       gc_assert(page_table[first_page].write_protected == 0);
-
-       /*
-       FSHOW((stderr,
-              "/first_page=%d bytes_used=%d\n",
-              first_page, page_table[first_page].bytes_used));
-       */
-
-       last_page = first_page;
-       bytes_found = 4096 - page_table[first_page].bytes_used;
-       num_pages = 1;
-       while ((bytes_found < nbytes)
-              && (last_page < (NUM_PAGES-1))
-              && (page_table[last_page+1].allocated == FREE_PAGE)) {
-           last_page++;
-           num_pages++;
-           bytes_found += 4096;
-           gc_assert(page_table[last_page].write_protected == 0);
-       }
-
-       region_size = (4096 - page_table[first_page].bytes_used)
-           + 4096*(last_page-first_page);
-
-       gc_assert(bytes_found == region_size);
-
-       /*
-       FSHOW((stderr,
-              "/last_page=%d bytes_found=%d num_pages=%d\n",
-              last_page, bytes_found, num_pages));
-       */
 
-       restart_page = last_page + 1;
-    } while ((restart_page < NUM_PAGES) && (bytes_found < nbytes));
+    get_spinlock(&free_pages_lock,(int) alloc_region);
 
-    /* Check for a failure */
-    if ((restart_page >= NUM_PAGES) && (bytes_found < nbytes)) {
-       fprintf(stderr,
-               "Argh! gc_alloc_large failed (restart_page), nbytes=%d.\n",
-               nbytes);
-       print_generation_stats(1);
-       lose(NULL);
+    if (unboxed) {
+       first_page =
+           generations[gc_alloc_generation].alloc_large_unboxed_start_page;
+    } else {
+       first_page = generations[gc_alloc_generation].alloc_large_start_page;
+    }
+    if (first_page <= alloc_region->last_page) {
+       first_page = alloc_region->last_page+1;
     }
 
-    /*
-    if (large)
-       FSHOW((stderr,
-              "/gc_alloc_large gen %d: %d of %d bytes: from pages %d to %d: addr=%x\n",
-              gc_alloc_generation,
-              nbytes,
-              bytes_found,
-              first_page,
-              last_page,
-              page_address(first_page)));
-    */
+    last_page=gc_find_freeish_pages(&first_page,nbytes,unboxed,0);
 
     gc_assert(first_page > alloc_region->last_page);
     if (unboxed)
@@ -1131,39 +964,134 @@ static void
     if (last_page+1 > last_free_page) {
        last_free_page = last_page+1;
        SetSymbolValue(ALLOCATION_POINTER,
-                      (lispobj)(((char *)heap_base) + last_free_page*4096));
-       if (last_page+1 > last_used_page)
-           last_used_page = last_page+1;
+                      (lispobj)(((char *)heap_base) + last_free_page*4096),0);
     }
+    release_spinlock(&free_pages_lock);
 
     return((void *)(page_address(first_page)+orig_first_page_bytes_used));
 }
 
-/* Allocate bytes from the boxed_region. It first checks if there is
- * room, if not then it calls gc_alloc_new_region to find a new region
- * with enough space. A pointer to the start of the region is returned. */
-static void
-*gc_alloc(int nbytes)
+int
+gc_find_freeish_pages(int *restart_page_ptr, int nbytes, int unboxed, struct alloc_region *alloc_region)
+{
+    /* if alloc_region is 0, we assume this is for a potentially large
+       object */
+    int first_page;
+    int last_page;
+    int region_size;
+    int restart_page=*restart_page_ptr;
+    int bytes_found;
+    int num_pages;
+    int large = !alloc_region && (nbytes >= large_object_size);
+
+    gc_assert(free_pages_lock);
+    /* Search for a contiguous free space of at least nbytes. If it's a
+       large object then align it on a page boundary by searching for a
+       free page. */
+
+    /* To allow the allocation of small objects without the danger of
+       using a page in the current boxed region, the search starts after
+       the current boxed free region. XX could probably keep a page
+       index ahead of the current region and bumped up here to save a
+       lot of re-scanning. */
+
+    do {
+       first_page = restart_page;
+       if (large)              
+           while ((first_page < NUM_PAGES)
+                  && (page_table[first_page].allocated != FREE_PAGE))
+               first_page++;
+       else
+           while (first_page < NUM_PAGES) {
+               if(page_table[first_page].allocated == FREE_PAGE)
+                   break;
+               /* I don't know why we need the gen=0 test, but it
+                * breaks randomly if that's omitted -dan 2003.02.26
+                */
+               if((page_table[first_page].allocated ==
+                   (unboxed ? UNBOXED_PAGE : BOXED_PAGE)) &&
+                  (page_table[first_page].large_object == 0) &&
+                  (gc_alloc_generation == 0) &&
+                  (page_table[first_page].gen == gc_alloc_generation) &&
+                  (page_table[first_page].bytes_used < (4096-32)) &&
+                  (page_table[first_page].write_protected == 0) &&
+                  (page_table[first_page].dont_move == 0))
+                   break;
+               first_page++;
+           }
+       
+       if (first_page >= NUM_PAGES) {
+           fprintf(stderr,
+                   "Argh! gc_find_free_space failed (first_page), nbytes=%d.\n",
+                   nbytes);
+           print_generation_stats(1);
+           lose(NULL);
+       }
+
+       gc_assert(page_table[first_page].write_protected == 0);
+
+       last_page = first_page;
+       bytes_found = 4096 - page_table[first_page].bytes_used;
+       num_pages = 1;
+       while (((bytes_found < nbytes) 
+               || (alloc_region && (num_pages < 2)))
+              && (last_page < (NUM_PAGES-1))
+              && (page_table[last_page+1].allocated == FREE_PAGE)) {
+           last_page++;
+           num_pages++;
+           bytes_found += 4096;
+           gc_assert(page_table[last_page].write_protected == 0);
+       }
+
+       region_size = (4096 - page_table[first_page].bytes_used)
+           + 4096*(last_page-first_page);
+
+       gc_assert(bytes_found == region_size);
+       restart_page = last_page + 1;
+    } while ((restart_page < NUM_PAGES) && (bytes_found < nbytes));
+
+    /* Check for a failure */
+    if ((restart_page >= NUM_PAGES) && (bytes_found < nbytes)) {
+       fprintf(stderr,
+               "Argh! gc_find_freeish_pages failed (restart_page), nbytes=%d.\n",
+               nbytes);
+       print_generation_stats(1);
+       lose(NULL);
+    }
+    *restart_page_ptr=first_page;
+    return last_page;
+}
+
+/* Allocate bytes.  All the rest of the special-purpose allocation
+ * functions will eventually call this (instead of just duplicating
+ * parts of its code) */
+
+void *
+gc_alloc_with_region(int nbytes,int unboxed_p, struct alloc_region *my_region,
+                    int quick_p)
 {
     void *new_free_pointer;
 
     /* FSHOW((stderr, "/gc_alloc %d\n", nbytes)); */
 
     /* Check whether there is room in the current alloc region. */
-    new_free_pointer = boxed_region.free_pointer + nbytes;
+    new_free_pointer = my_region->free_pointer + nbytes;
 
-    if (new_free_pointer <= boxed_region.end_addr) {
+    if (new_free_pointer <= my_region->end_addr) {
        /* If so then allocate from the current alloc region. */
-       void *new_obj = boxed_region.free_pointer;
-       boxed_region.free_pointer = new_free_pointer;
-
-       /* Check whether the alloc region is almost empty. */
-       if ((boxed_region.end_addr - boxed_region.free_pointer) <= 32) {
-           /* If so finished with the current region. */
-           gc_alloc_update_page_tables(0, &boxed_region);
+       void *new_obj = my_region->free_pointer;
+       my_region->free_pointer = new_free_pointer;
+
+       /* Unless a `quick' alloc was requested, check whether the
+          alloc region is almost empty. */
+       if (!quick_p &&
+           (my_region->end_addr - my_region->free_pointer) <= 32) {
+           /* If so, finished with the current region. */
+           gc_alloc_update_page_tables(unboxed_p, my_region);
            /* Set up a new region. */
-           gc_alloc_new_region(32, 0, &boxed_region);
+           gc_alloc_new_region(32 /*bytes*/, unboxed_p, my_region);
        }
+
        return((void *)new_obj);
     }
 
@@ -1172,34 +1100,33 @@ static void
     /* If there some room left in the current region, enough to be worth
      * saving, then allocate a large object. */
     /* FIXME: "32" should be a named parameter. */
-    if ((boxed_region.end_addr-boxed_region.free_pointer) > 32)
-       return gc_alloc_large(nbytes, 0, &boxed_region);
+    if ((my_region->end_addr-my_region->free_pointer) > 32)
+       return gc_alloc_large(nbytes, unboxed_p, my_region);
 
     /* Else find a new region. */
 
     /* Finished with the current region. */
-    gc_alloc_update_page_tables(0, &boxed_region);
+    gc_alloc_update_page_tables(unboxed_p, my_region);
 
     /* Set up a new region. */
-    gc_alloc_new_region(nbytes, 0, &boxed_region);
+    gc_alloc_new_region(nbytes, unboxed_p, my_region);
 
     /* Should now be enough room. */
 
     /* Check whether there is room in the current region. */
-    new_free_pointer = boxed_region.free_pointer + nbytes;
+    new_free_pointer = my_region->free_pointer + nbytes;
 
-    if (new_free_pointer <= boxed_region.end_addr) {
+    if (new_free_pointer <= my_region->end_addr) {
        /* If so then allocate from the current region. */
-       void *new_obj = boxed_region.free_pointer;
-       boxed_region.free_pointer = new_free_pointer;
-
+       void *new_obj = my_region->free_pointer;
+       my_region->free_pointer = new_free_pointer;
        /* Check whether the current region is almost empty. */
-       if ((boxed_region.end_addr - boxed_region.free_pointer) <= 32) {
+       if ((my_region->end_addr - my_region->free_pointer) <= 32) {
            /* If so find, finished with the current region. */
-           gc_alloc_update_page_tables(0, &boxed_region);
+           gc_alloc_update_page_tables(unboxed_p, my_region);
 
            /* Set up a new region. */
-           gc_alloc_new_region(32, 0, &boxed_region);
+           gc_alloc_new_region(32, unboxed_p, my_region);
        }
 
        return((void *)new_obj);
@@ -1210,252 +1137,92 @@ static void
     return((void *) NIL); /* dummy value: return something ... */
 }
 
-/* Allocate space from the boxed_region. If there is not enough free
- * space then call gc_alloc to do the job. A pointer to the start of
- * the region is returned. */
-static inline void
-*gc_quick_alloc(int nbytes)
+void *
+gc_general_alloc(int nbytes,int unboxed_p,int quick_p)
 {
-    void *new_free_pointer;
+    struct alloc_region *my_region = 
+      unboxed_p ? &unboxed_region : &boxed_region;
+    return gc_alloc_with_region(nbytes,unboxed_p, my_region,quick_p);
+}
 
-    /* Check whether there is room in the current region. */
-    new_free_pointer = boxed_region.free_pointer + nbytes;
 
-    if (new_free_pointer <= boxed_region.end_addr) {
-       /* If so then allocate from the current region. */
-       void  *new_obj = boxed_region.free_pointer;
-       boxed_region.free_pointer = new_free_pointer;
-       return((void *)new_obj);
-    }
 
-    /* Else call gc_alloc */
-    return (gc_alloc(nbytes));
+static void *
+gc_alloc(int nbytes,int unboxed_p)
+{
+    /* this is the only function that the external interface to
+     * allocation presently knows how to call: Lisp code will never
+     * allocate large objects, or to unboxed space, or `quick'ly.
+     * Any of that stuff will only ever happen inside of GC */
+    return gc_general_alloc(nbytes,unboxed_p,0);
 }
 
-/* Allocate space for the boxed object. If it is a large object then
- * do a large alloc else allocate from the current region. If there is
- * not enough free space then call gc_alloc to do the job. A pointer
- * to the start of the region is returned. */
-static inline void
-*gc_quick_alloc_large(int nbytes)
+/* Allocate space from the boxed_region. If there is not enough free
+ * space then call gc_alloc to do the job. A pointer to the start of
+ * the object is returned. */
+static inline void *
+gc_quick_alloc(int nbytes)
 {
-    void *new_free_pointer;
+    return gc_general_alloc(nbytes,ALLOC_BOXED,ALLOC_QUICK);
+}
 
-    if (nbytes >= large_object_size)
-       return gc_alloc_large(nbytes, 0, &boxed_region);
-
-    /* Check whether there is room in the current region. */
-    new_free_pointer = boxed_region.free_pointer + nbytes;
-
-    if (new_free_pointer <= boxed_region.end_addr) {
-       /* If so then allocate from the current region. */
-       void *new_obj = boxed_region.free_pointer;
-       boxed_region.free_pointer = new_free_pointer;
-       return((void *)new_obj);
-    }
+/* Allocate space for the possibly large boxed object. If it is a
+ * large object then do a large alloc else use gc_quick_alloc.  Note
+ * that gc_quick_alloc will eventually fall through to
+ * gc_general_alloc which may allocate the object in a large way
+ * anyway, but based on decisions about the free space in the current
+ * region, not the object size itself */
 
-    /* Else call gc_alloc */
-    return (gc_alloc(nbytes));
+static inline void *
+gc_quick_alloc_large(int nbytes)
+{
+    if (nbytes >= large_object_size)
+       return gc_alloc_large(nbytes, ALLOC_BOXED, &boxed_region);
+    else
+       return gc_general_alloc(nbytes,ALLOC_BOXED,ALLOC_QUICK);
 }
 
-static void
-*gc_alloc_unboxed(int nbytes)
+static inline void *
+gc_alloc_unboxed(int nbytes)
 {
-    void *new_free_pointer;
-
-    /*
-    FSHOW((stderr, "/gc_alloc_unboxed %d\n", nbytes));
-    */
-
-    /* Check whether there is room in the current region. */
-    new_free_pointer = unboxed_region.free_pointer + nbytes;
-
-    if (new_free_pointer <= unboxed_region.end_addr) {
-       /* If so then allocate from the current region. */
-       void *new_obj = unboxed_region.free_pointer;
-       unboxed_region.free_pointer = new_free_pointer;
-
-       /* Check whether the current region is almost empty. */
-       if ((unboxed_region.end_addr - unboxed_region.free_pointer) <= 32) {
-           /* If so finished with the current region. */
-           gc_alloc_update_page_tables(1, &unboxed_region);
-
-           /* Set up a new region. */
-           gc_alloc_new_region(32, 1, &unboxed_region);
-       }
-
-       return((void *)new_obj);
-    }
-
-    /* Else not enough free space in the current region. */
-
-    /* If there is a bit of room left in the current region then
-       allocate a large object. */
-    if ((unboxed_region.end_addr-unboxed_region.free_pointer) > 32)
-       return gc_alloc_large(nbytes,1,&unboxed_region);
-
-    /* Else find a new region. */
-
-    /* Finished with the current region. */
-    gc_alloc_update_page_tables(1, &unboxed_region);
-
-    /* Set up a new region. */
-    gc_alloc_new_region(nbytes, 1, &unboxed_region);
-
-    /* Should now be enough room. */
-
-    /* Check whether there is room in the current region. */
-    new_free_pointer = unboxed_region.free_pointer + nbytes;
-
-    if (new_free_pointer <= unboxed_region.end_addr) {
-       /* If so then allocate from the current region. */
-       void *new_obj = unboxed_region.free_pointer;
-       unboxed_region.free_pointer = new_free_pointer;
-
-       /* Check whether the current region is almost empty. */
-       if ((unboxed_region.end_addr - unboxed_region.free_pointer) <= 32) {
-           /* If so find, finished with the current region. */
-           gc_alloc_update_page_tables(1, &unboxed_region);
-
-           /* Set up a new region. */
-           gc_alloc_new_region(32, 1, &unboxed_region);
-       }
-
-       return((void *)new_obj);
-    }
-
-    /* shouldn't happen? */
-    gc_assert(0);
-    return((void *) NIL); /* dummy value: return something ... */
+    return gc_general_alloc(nbytes,ALLOC_UNBOXED,0);
 }
 
-static inline void
-*gc_quick_alloc_unboxed(int nbytes)
+static inline void *
+gc_quick_alloc_unboxed(int nbytes)
 {
-    void *new_free_pointer;
-
-    /* Check whether there is room in the current region. */
-    new_free_pointer = unboxed_region.free_pointer + nbytes;
-
-    if (new_free_pointer <= unboxed_region.end_addr) {
-       /* If so then allocate from the current region. */
-       void *new_obj = unboxed_region.free_pointer;
-       unboxed_region.free_pointer = new_free_pointer;
-
-       return((void *)new_obj);
-    }
-
-    /* Else call gc_alloc */
-    return (gc_alloc_unboxed(nbytes));
+    return gc_general_alloc(nbytes,ALLOC_UNBOXED,ALLOC_QUICK);
 }
 
 /* Allocate space for the object. If it is a large object then do a
  * large alloc else allocate from the current region. If there is not
- * enough free space then call gc_alloc to do the job.
+ * enough free space then call general gc_alloc_unboxed() to do the job.
  *
- * A pointer to the start of the region is returned. */
-static inline void
-*gc_quick_alloc_large_unboxed(int nbytes)
+ * A pointer to the start of the object is returned. */
+static inline void *
+gc_quick_alloc_large_unboxed(int nbytes)
 {
-    void *new_free_pointer;
-
     if (nbytes >= large_object_size)
-       return gc_alloc_large(nbytes,1,&unboxed_region);
-
-    /* Check whether there is room in the current region. */
-    new_free_pointer = unboxed_region.free_pointer + nbytes;
-
-    if (new_free_pointer <= unboxed_region.end_addr) {
-       /* If so then allocate from the current region. */
-       void *new_obj = unboxed_region.free_pointer;
-       unboxed_region.free_pointer = new_free_pointer;
-
-       return((void *)new_obj);
-    }
-
-    /* Else call gc_alloc. */
-    return (gc_alloc_unboxed(nbytes));
+       return gc_alloc_large(nbytes,ALLOC_UNBOXED,&unboxed_region);
+    else
+       return gc_quick_alloc_unboxed(nbytes);
 }
 \f
 /*
  * scavenging/transporting routines derived from gc.c in CMU CL ca. 18b
  */
 
-static int (*scavtab[256])(lispobj *where, lispobj object);
-static lispobj (*transother[256])(lispobj object);
-static int (*sizetab[256])(lispobj *where);
-
-static struct weak_pointer *weak_pointers;
-
-#define CEILING(x,y) (((x) + ((y) - 1)) & (~((y) - 1)))
-\f
-/*
- * predicates
- */
-
-static inline boolean
-from_space_p(lispobj obj)
-{
-    int page_index=(void*)obj - heap_base;
-    return ((page_index >= 0)
-           && ((page_index = ((unsigned int)page_index)/4096) < NUM_PAGES)
-           && (page_table[page_index].gen == from_space));
-}
-
-static inline boolean
-new_space_p(lispobj obj)
-{
-    int page_index = (void*)obj - heap_base;
-    return ((page_index >= 0)
-           && ((page_index = ((unsigned int)page_index)/4096) < NUM_PAGES)
-           && (page_table[page_index].gen == new_space));
-}
-\f
-/*
- * copying objects
- */
-
-/* to copy a boxed object */
-static inline lispobj
-copy_object(lispobj object, int nwords)
-{
-    int tag;
-    lispobj *new;
-    lispobj *source, *dest;
-
-    gc_assert(Pointerp(object));
-    gc_assert(from_space_p(object));
-    gc_assert((nwords & 0x01) == 0);
-
-    /* Get tag of object. */
-    tag = LowtagOf(object);
-
-    /* Allocate space. */
-    new = gc_quick_alloc(nwords*4);
-
-    dest = new;
-    source = (lispobj *) PTR(object);
-
-    /* Copy the object. */
-    while (nwords > 0) {
-       dest[0] = source[0];
-       dest[1] = source[1];
-       dest += 2;
-       source += 2;
-       nwords -= 2;
-    }
-
-    /* Return Lisp pointer of new object. */
-    return ((lispobj) new) | tag;
-}
+extern int (*scavtab[256])(lispobj *where, lispobj object);
+extern lispobj (*transother[256])(lispobj object);
+extern int (*sizetab[256])(lispobj *where);
 
-/* to copy a large boxed object. If the object is in a large object
+/* Copy a large boxed object. If the object is in a large object
  * region then it is simply promoted, else it is copied. If it's large
  * enough then it's copied to a large object region.
  *
  * Vectors may have shrunk. If the object is not copied the space
  * needs to be reclaimed, and the page_tables corrected. */
-static lispobj
+lispobj
 copy_large_object(lispobj object, int nwords)
 {
     int tag;
@@ -1463,13 +1230,10 @@ copy_large_object(lispobj object, int nwords)
     lispobj *source, *dest;
     int first_page;
 
-    gc_assert(Pointerp(object));
+    gc_assert(is_lisp_pointer(object));
     gc_assert(from_space_p(object));
     gc_assert((nwords & 0x01) == 0);
 
-    if ((nwords > 1024*1024) && gencgc_verbose) {
-       FSHOW((stderr, "/copy_large_object: %d bytes\n", nwords*4));
-    }
 
     /* Check whether it's a large object. */
     first_page = find_page_index((void *)object);
@@ -1521,7 +1285,7 @@ copy_large_object(lispobj object, int nwords)
        gc_assert(page_table[next_page].bytes_used >= remaining_bytes);
 
        page_table[next_page].gen = new_space;
-       gc_assert(page_table[next_page].allocated = BOXED_PAGE);
+       gc_assert(page_table[next_page].allocated == BOXED_PAGE);
 
        /* Adjust the bytes_used. */
        old_bytes_used = page_table[next_page].bytes_used;
@@ -1537,7 +1301,7 @@ copy_large_object(lispobj object, int nwords)
               page_table[next_page].large_object &&
               (page_table[next_page].first_object_offset ==
                -(next_page - first_page)*4096)) {
-           /* Checks out OK, free the page. Don't need to both zeroing
+           /* Checks out OK, free the page. Don't need to bother zeroing
             * pages as this should have been done before shrinking the
             * object. These pages shouldn't be write-protected as they
             * should be zero filled. */
@@ -1550,9 +1314,6 @@ copy_large_object(lispobj object, int nwords)
            next_page++;
        }
 
-       if ((bytes_freed > 0) && gencgc_verbose)
-           FSHOW((stderr, "/copy_large_boxed bytes_freed=%d\n", bytes_freed));
-
        generations[from_space].bytes_allocated -= 4*nwords + bytes_freed;
        generations[new_space].bytes_allocated += 4*nwords;
        bytes_allocated -= bytes_freed;
@@ -1563,13 +1324,13 @@ copy_large_object(lispobj object, int nwords)
        return(object);
     } else {
        /* Get tag of object. */
-       tag = LowtagOf(object);
+       tag = lowtag_of(object);
 
        /* Allocate space. */
        new = gc_quick_alloc_large(nwords*4);
 
        dest = new;
-       source = (lispobj *) PTR(object);
+       source = (lispobj *) native_pointer(object);
 
        /* Copy the object. */
        while (nwords > 0) {
@@ -1586,25 +1347,25 @@ copy_large_object(lispobj object, int nwords)
 }
 
 /* to copy unboxed objects */
-static inline lispobj
+lispobj
 copy_unboxed_object(lispobj object, int nwords)
 {
     int tag;
     lispobj *new;
     lispobj *source, *dest;
 
-    gc_assert(Pointerp(object));
+    gc_assert(is_lisp_pointer(object));
     gc_assert(from_space_p(object));
     gc_assert((nwords & 0x01) == 0);
 
     /* Get tag of object. */
-    tag = LowtagOf(object);
+    tag = lowtag_of(object);
 
     /* Allocate space. */
     new = gc_quick_alloc_unboxed(nwords*4);
 
     dest = new;
-    source = (lispobj *) PTR(object);
+    source = (lispobj *) native_pointer(object);
 
     /* Copy the object. */
     while (nwords > 0) {
@@ -1630,7 +1391,7 @@ copy_unboxed_object(lispobj object, int nwords)
  *
  * KLUDGE: There's a lot of cut-and-paste duplication between this
  * function and copy_large_object(..). -- WHN 20000619 */
-static lispobj
+lispobj
 copy_large_unboxed_object(lispobj object, int nwords)
 {
     int tag;
@@ -1638,7 +1399,7 @@ copy_large_unboxed_object(lispobj object, int nwords)
     lispobj *source, *dest;
     int first_page;
 
-    gc_assert(Pointerp(object));
+    gc_assert(is_lisp_pointer(object));
     gc_assert(from_space_p(object));
     gc_assert((nwords & 0x01) == 0);
 
@@ -1727,13 +1488,13 @@ copy_large_unboxed_object(lispobj object, int nwords)
     }
     else {
        /* Get tag of object. */
-       tag = LowtagOf(object);
+       tag = lowtag_of(object);
 
        /* Allocate space. */
        new = gc_quick_alloc_large_unboxed(nwords*4);
 
        dest = new;
-       source = (lispobj *) PTR(object);
+       source = (lispobj *) native_pointer(object);
 
        /* Copy the object. */
        while (nwords > 0) {
@@ -1748,107 +1509,18 @@ copy_large_unboxed_object(lispobj object, int nwords)
        return ((lispobj) new) | tag;
     }
 }
-\f
-/*
- * scavenging
- */
 
-/* FIXME: Most calls end up going to some trouble to compute an
- * 'n_words' value for this function. The system might be a little
- * simpler if this function used an 'end' parameter instead. */
-static void
-scavenge(lispobj *start, long n_words)
-{
-    lispobj *end = start + n_words;
-    lispobj *object_ptr;
-    int n_words_scavenged;
-    
-    for (object_ptr = start;
-        object_ptr < end;
-        object_ptr += n_words_scavenged) {
 
-       lispobj object = *object_ptr;
-       
-       gc_assert(object != 0x01); /* not a forwarding pointer */
-
-       if (Pointerp(object)) {
-           if (from_space_p(object)) {
-               /* It currently points to old space. Check for a
-                * forwarding pointer. */
-               lispobj *ptr = (lispobj *)PTR(object);
-               lispobj first_word = *ptr;
-               if (first_word == 0x01) {
-                   /* Yes, there's a forwarding pointer. */
-                   *object_ptr = ptr[1];
-                   n_words_scavenged = 1;
-               } else {
-                   /* Scavenge that pointer. */
-                   n_words_scavenged =
-                       (scavtab[TypeOf(object)])(object_ptr, object);
-               }
-           } else {
-               /* It points somewhere other than oldspace. Leave it
-                * alone. */
-               n_words_scavenged = 1;
-           }
-       } else if ((object & 3) == 0) {
-           /* It's a fixnum: really easy.. */
-           n_words_scavenged = 1;
-       } else {
-           /* It's some sort of header object or another. */
-           n_words_scavenged =
-               (scavtab[TypeOf(object)])(object_ptr, object);
-       }
-    }
-    gc_assert(object_ptr == end);
-}
+
 \f
+
 /*
  * code and code-related objects
  */
-
-#define RAW_ADDR_OFFSET (6*sizeof(lispobj) - type_FunctionPointer)
-
-static lispobj trans_function_header(lispobj object);
+/*
+static lispobj trans_fun_header(lispobj object);
 static lispobj trans_boxed(lispobj object);
-
-static int
-scav_function_pointer(lispobj *where, lispobj object)
-{
-    lispobj *first_pointer;
-    lispobj copy;
-
-    gc_assert(Pointerp(object));
-
-    /* Object is a pointer into from space - no a FP. */
-    first_pointer = (lispobj *) PTR(object);
-
-    /* must transport object -- object may point to either a function
-     * header, a closure function header, or to a closure header. */
-
-    switch (TypeOf(*first_pointer)) {
-    case type_FunctionHeader:
-    case type_ClosureFunctionHeader:
-       copy = trans_function_header(object);
-       break;
-    default:
-       copy = trans_boxed(object);
-       break;
-    }
-
-    if (copy != object) {
-       /* Set forwarding pointer */
-       first_pointer[0] = 0x01;
-       first_pointer[1] = copy;
-    }
-
-    gc_assert(Pointerp(copy));
-    gc_assert(!from_space_p(copy));
-
-    *where = copy;
-
-    return 1;
-}
+*/
 
 /* Scan a x86 compiled code object, looking for possible fixups that
  * have been missed after a move.
@@ -1871,15 +1543,6 @@ sniff_code_object(struct code *code, unsigned displacement)
     if (!check_code_fixups)
        return;
 
-    /* It's ok if it's byte compiled code. The trace table offset will
-     * be a fixnum if it's x86 compiled code - check. */
-    if (code->trace_table_offset & 0x3) {
-       FSHOW((stderr, "/Sniffing byte compiled code object at %x.\n", code));
-       return;
-    }
-
-    /* Else it's x86 machine code. */
-
     ncode_words = fixnum_value(code->code_size);
     nheader_words = HeaderValue(*(lispobj *)code);
     nwords = ncode_words + nheader_words;
@@ -1896,8 +1559,10 @@ sniff_code_object(struct code *code, unsigned displacement)
        unsigned d2 = *((unsigned char *)p - 2);
        unsigned d3 = *((unsigned char *)p - 3);
        unsigned d4 = *((unsigned char *)p - 4);
+#if QSHOW
        unsigned d5 = *((unsigned char *)p - 5);
        unsigned d6 = *((unsigned char *)p - 6);
+#endif
 
        /* Check for code references. */
        /* Check for a 32 bit word that looks like an absolute
@@ -2036,8 +1701,8 @@ sniff_code_object(struct code *code, unsigned displacement)
     }
 }
 
-static void
-apply_code_fixups(struct code *old_code, struct code *new_code)
+void
+gencgc_apply_code_fixups(struct code *old_code, struct code *new_code)
 {
     int nheader_words, ncode_words, nwords;
     void *constants_start_addr, *constants_end_addr;
@@ -2046,14 +1711,6 @@ apply_code_fixups(struct code *old_code, struct code *new_code)
     unsigned displacement = (unsigned)new_code - (unsigned)old_code;
     struct vector *fixups_vector;
 
-    /* It's OK if it's byte compiled code. The trace table offset will
-     * be a fixnum if it's x86 compiled code - check. */
-    if (new_code->trace_table_offset & 0x3) {
-/*     FSHOW((stderr, "/byte compiled code object at %x\n", new_code)); */
-       return;
-    }
-
-    /* Else it's x86 machine code. */
     ncode_words = fixnum_value(new_code->code_size);
     nheader_words = HeaderValue(*(lispobj *)new_code);
     nwords = ncode_words + nheader_words;
@@ -2079,7 +1736,8 @@ apply_code_fixups(struct code *old_code, struct code *new_code)
 
     /* It will be 0 or the unbound-marker if there are no fixups, and
      * will be an other pointer if it is valid. */
-    if ((fixups == 0) || (fixups == type_UnboundMarker) || !Pointerp(fixups)) {
+    if ((fixups == 0) || (fixups == UNBOUND_MARKER_WIDETAG) ||
+       !is_lisp_pointer(fixups)) {
        /* Check for possible errors. */
        if (check_code_fixups)
            sniff_code_object(new_code, displacement);
@@ -2093,19 +1751,21 @@ apply_code_fixups(struct code *old_code, struct code *new_code)
        return;
     }
 
-    fixups_vector = (struct vector *)PTR(fixups);
+    fixups_vector = (struct vector *)native_pointer(fixups);
 
     /* Could be pointing to a forwarding pointer. */
-    if (Pointerp(fixups) && (find_page_index((void*)fixups_vector) != -1)
-       && (fixups_vector->header == 0x01)) {
+    if (is_lisp_pointer(fixups) &&
+       (find_page_index((void*)fixups_vector) != -1) &&
+       (fixups_vector->header == 0x01)) {
        /* If so, then follow it. */
        /*SHOW("following pointer to a forwarding pointer");*/
-       fixups_vector = (struct vector *)PTR((lispobj)fixups_vector->length);
+       fixups_vector = (struct vector *)native_pointer((lispobj)fixups_vector->length);
     }
 
     /*SHOW("got fixups");*/
 
-    if (TypeOf(fixups_vector->header) == type_SimpleArrayUnsignedByte32) {
+    if (widetag_of(fixups_vector->header) ==
+       SIMPLE_ARRAY_UNSIGNED_BYTE_32_WIDETAG) {
        /* Got the fixups for the code block. Now work through the vector,
           and apply a fixup at each address. */
        int length = fixnum_value(fixups_vector->length);
@@ -2138,651 +1798,112 @@ apply_code_fixups(struct code *old_code, struct code *new_code)
     }
 }
 
-static struct code *
-trans_code(struct code *code)
-{
-    struct code *new_code;
-    lispobj l_code, l_new_code;
-    int nheader_words, ncode_words, nwords;
-    unsigned long displacement;
-    lispobj fheaderl, *prev_pointer;
-
-    /* FSHOW((stderr,
-             "\n/transporting code object located at 0x%08x\n",
-            (unsigned long) code)); */
 
-    /* If object has already been transported, just return pointer. */
-    if (*((lispobj *)code) == 0x01)
-       return (struct code*)(((lispobj *)code)[1]);
+static lispobj
+trans_boxed_large(lispobj object)
+{
+    lispobj header;
+    unsigned long length;
 
-    gc_assert(TypeOf(code->header) == type_CodeHeader);
+    gc_assert(is_lisp_pointer(object));
 
-    /* Prepare to transport the code vector. */
-    l_code = (lispobj) code | type_OtherPointer;
+    header = *((lispobj *) native_pointer(object));
+    length = HeaderValue(header) + 1;
+    length = CEILING(length, 2);
 
-    ncode_words = fixnum_value(code->code_size);
-    nheader_words = HeaderValue(code->header);
-    nwords = ncode_words + nheader_words;
-    nwords = CEILING(nwords, 2);
+    return copy_large_object(object, length);
+}
 
-    l_new_code = copy_large_object(l_code, nwords);
-    new_code = (struct code *) PTR(l_new_code);
 
-    /* may not have been moved.. */
-    if (new_code == code)
-       return new_code;
+static lispobj
+trans_unboxed_large(lispobj object)
+{
+    lispobj header;
+    unsigned long length;
 
-    displacement = l_new_code - l_code;
 
-    /*
-    FSHOW((stderr,
-          "/old code object at 0x%08x, new code object at 0x%08x\n",
-          (unsigned long) code,
-          (unsigned long) new_code));
-    FSHOW((stderr, "/Code object is %d words long.\n", nwords));
-    */
+    gc_assert(is_lisp_pointer(object));
 
-    /* Set forwarding pointer. */
-    ((lispobj *)code)[0] = 0x01;
-    ((lispobj *)code)[1] = l_new_code;
+    header = *((lispobj *) native_pointer(object));
+    length = HeaderValue(header) + 1;
+    length = CEILING(length, 2);
 
-    /* Set forwarding pointers for all the function headers in the
-     * code object. Also fix all self pointers. */
+    return copy_large_unboxed_object(object, length);
+}
 
-    fheaderl = code->entry_points;
-    prev_pointer = &new_code->entry_points;
+\f
+/*
+ * vector-like objects
+ */
 
-    while (fheaderl != NIL) {
-       struct function *fheaderp, *nfheaderp;
-       lispobj nfheaderl;
 
-       fheaderp = (struct function *) PTR(fheaderl);
-       gc_assert(TypeOf(fheaderp->header) == type_FunctionHeader);
+/* FIXME: What does this mean? */
+int gencgc_hash = 1;
 
-       /* Calculate the new function pointer and the new */
-       /* function header. */
-       nfheaderl = fheaderl + displacement;
-       nfheaderp = (struct function *) PTR(nfheaderl);
+static int
+scav_vector(lispobj *where, lispobj object)
+{
+    unsigned int kv_length;
+    lispobj *kv_vector;
+    unsigned int length = 0; /* (0 = dummy to stop GCC warning) */
+    lispobj *hash_table;
+    lispobj empty_symbol;
+    unsigned int *index_vector = NULL; /* (NULL = dummy to stop GCC warning) */
+    unsigned int *next_vector = NULL; /* (NULL = dummy to stop GCC warning) */
+    unsigned int *hash_vector = NULL; /* (NULL = dummy to stop GCC warning) */
+    lispobj weak_p_obj;
+    unsigned next_vector_length = 0;
 
-       /* Set forwarding pointer. */
-       ((lispobj *)fheaderp)[0] = 0x01;
-       ((lispobj *)fheaderp)[1] = nfheaderl;
+    /* FIXME: A comment explaining this would be nice. It looks as
+     * though SB-VM:VECTOR-VALID-HASHING-SUBTYPE is set for EQ-based
+     * hash tables in the Lisp HASH-TABLE code, and nowhere else. */
+    if (HeaderValue(object) != subtype_VectorValidHashing)
+       return 1;
 
-       /* Fix self pointer. */
-       nfheaderp->self = nfheaderl + RAW_ADDR_OFFSET;
+    if (!gencgc_hash) {
+       /* This is set for backward compatibility. FIXME: Do we need
+        * this any more? */
+       *where =
+           (subtype_VectorMustRehash<<N_WIDETAG_BITS) | SIMPLE_VECTOR_WIDETAG;
+       return 1;
+    }
 
-       *prev_pointer = nfheaderl;
+    kv_length = fixnum_value(where[1]);
+    kv_vector = where + 2;  /* Skip the header and length. */
+    /*FSHOW((stderr,"/kv_length = %d\n", kv_length));*/
 
-       fheaderl = fheaderp->next;
-       prev_pointer = &nfheaderp->next;
+    /* Scavenge element 0, which may be a hash-table structure. */
+    scavenge(where+2, 1);
+    if (!is_lisp_pointer(where[2])) {
+       lose("no pointer at %x in hash table", where[2]);
+    }
+    hash_table = (lispobj *)native_pointer(where[2]);
+    /*FSHOW((stderr,"/hash_table = %x\n", hash_table));*/
+    if (widetag_of(hash_table[0]) != INSTANCE_HEADER_WIDETAG) {
+       lose("hash table not instance (%x at %x)", hash_table[0], hash_table);
     }
 
-    /*  sniff_code_object(new_code,displacement);*/
-    apply_code_fixups(code,new_code);
+    /* Scavenge element 1, which should be some internal symbol that
+     * the hash table code reserves for marking empty slots. */
+    scavenge(where+3, 1);
+    if (!is_lisp_pointer(where[3])) {
+       lose("not empty-hash-table-slot symbol pointer: %x", where[3]);
+    }
+    empty_symbol = where[3];
+    /* fprintf(stderr,"* empty_symbol = %x\n", empty_symbol);*/
+    if (widetag_of(*(lispobj *)native_pointer(empty_symbol)) !=
+       SYMBOL_HEADER_WIDETAG) {
+       lose("not a symbol where empty-hash-table-slot symbol expected: %x",
+            *(lispobj *)native_pointer(empty_symbol));
+    }
 
-    return new_code;
-}
+    /* Scavenge hash table, which will fix the positions of the other
+     * needed objects. */
+    scavenge(hash_table, 16);
 
-static int
-scav_code_header(lispobj *where, lispobj object)
-{
-    struct code *code;
-    int n_header_words, n_code_words, n_words;
-    lispobj entry_point;       /* tagged pointer to entry point */
-    struct function *function_ptr; /* untagged pointer to entry point */
-
-    code = (struct code *) where;
-    n_code_words = fixnum_value(code->code_size);
-    n_header_words = HeaderValue(object);
-    n_words = n_code_words + n_header_words;
-    n_words = CEILING(n_words, 2);
-
-    /* Scavenge the boxed section of the code data block. */
-    scavenge(where + 1, n_header_words - 1);
-
-    /* Scavenge the boxed section of each function object in the */
-    /* code data block. */
-    for (entry_point = code->entry_points;
-        entry_point != NIL;
-        entry_point = function_ptr->next) {
-
-       gc_assert(Pointerp(entry_point));
-
-       function_ptr = (struct function *) PTR(entry_point);
-       gc_assert(TypeOf(function_ptr->header) == type_FunctionHeader);
-
-       scavenge(&function_ptr->name, 1);
-       scavenge(&function_ptr->arglist, 1);
-       scavenge(&function_ptr->type, 1);
-    }
-       
-    return n_words;
-}
-
-static lispobj
-trans_code_header(lispobj object)
-{
-    struct code *ncode;
-
-    ncode = trans_code((struct code *) PTR(object));
-    return (lispobj) ncode | type_OtherPointer;
-}
-
-static int
-size_code_header(lispobj *where)
-{
-    struct code *code;
-    int nheader_words, ncode_words, nwords;
-
-    code = (struct code *) where;
-       
-    ncode_words = fixnum_value(code->code_size);
-    nheader_words = HeaderValue(code->header);
-    nwords = ncode_words + nheader_words;
-    nwords = CEILING(nwords, 2);
-
-    return nwords;
-}
-
-static int
-scav_return_pc_header(lispobj *where, lispobj object)
-{
-    lose("attempted to scavenge a return PC header where=0x%08x object=0x%08x",
-        (unsigned long) where,
-        (unsigned long) object);
-    return 0; /* bogus return value to satisfy static type checking */
-}
-
-static lispobj
-trans_return_pc_header(lispobj object)
-{
-    struct function *return_pc;
-    unsigned long offset;
-    struct code *code, *ncode;
-
-    SHOW("/trans_return_pc_header: Will this work?");
-
-    return_pc = (struct function *) PTR(object);
-    offset = HeaderValue(return_pc->header) * 4;
-
-    /* Transport the whole code object. */
-    code = (struct code *) ((unsigned long) return_pc - offset);
-    ncode = trans_code(code);
-
-    return ((lispobj) ncode + offset) | type_OtherPointer;
-}
-
-/* On the 386, closures hold a pointer to the raw address instead of the
- * function object. */
-#ifdef __i386__
-static int
-scav_closure_header(lispobj *where, lispobj object)
-{
-    struct closure *closure;
-    lispobj fun;
-
-    closure = (struct closure *)where;
-    fun = closure->function - RAW_ADDR_OFFSET;
-    scavenge(&fun, 1);
-    /* The function may have moved so update the raw address. But
-     * don't write unnecessarily. */
-    if (closure->function != fun + RAW_ADDR_OFFSET)
-       closure->function = fun + RAW_ADDR_OFFSET;
-
-    return 2;
-}
-#endif
-
-static int
-scav_function_header(lispobj *where, lispobj object)
-{
-    lose("attempted to scavenge a function header where=0x%08x object=0x%08x",
-        (unsigned long) where,
-        (unsigned long) object);
-    return 0; /* bogus return value to satisfy static type checking */
-}
-
-static lispobj
-trans_function_header(lispobj object)
-{
-    struct function *fheader;
-    unsigned long offset;
-    struct code *code, *ncode;
-
-    fheader = (struct function *) PTR(object);
-    offset = HeaderValue(fheader->header) * 4;
-
-    /* Transport the whole code object. */
-    code = (struct code *) ((unsigned long) fheader - offset);
-    ncode = trans_code(code);
-
-    return ((lispobj) ncode + offset) | type_FunctionPointer;
-}
-\f
-/*
- * instances
- */
-
-static int
-scav_instance_pointer(lispobj *where, lispobj object)
-{
-    lispobj copy, *first_pointer;
-
-    /* Object is a pointer into from space - not a FP. */
-    copy = trans_boxed(object);
-
-    gc_assert(copy != object);
-
-    first_pointer = (lispobj *) PTR(object);
-
-    /* Set forwarding pointer. */
-    first_pointer[0] = 0x01;
-    first_pointer[1] = copy;
-    *where = copy;
-
-    return 1;
-}
-\f
-/*
- * lists and conses
- */
-
-static lispobj trans_list(lispobj object);
-
-static int
-scav_list_pointer(lispobj *where, lispobj object)
-{
-    lispobj first, *first_pointer;
-
-    gc_assert(Pointerp(object));
-
-    /* Object is a pointer into from space - not FP. */
-
-    first = trans_list(object);
-    gc_assert(first != object);
-
-    first_pointer = (lispobj *) PTR(object);
-
-    /* Set forwarding pointer */
-    first_pointer[0] = 0x01;
-    first_pointer[1] = first;
-
-    gc_assert(Pointerp(first));
-    gc_assert(!from_space_p(first));
-    *where = first;
-    return 1;
-}
-
-static lispobj
-trans_list(lispobj object)
-{
-    lispobj new_list_pointer;
-    struct cons *cons, *new_cons;
-    lispobj cdr;
-
-    gc_assert(from_space_p(object));
-
-    cons = (struct cons *) PTR(object);
-
-    /* Copy 'object'. */
-    new_cons = (struct cons *) gc_quick_alloc(sizeof(struct cons));
-    new_cons->car = cons->car;
-    new_cons->cdr = cons->cdr; /* updated later */
-    new_list_pointer = (lispobj)new_cons | LowtagOf(object);
-
-    /* Grab the cdr before it is clobbered. */
-    cdr = cons->cdr;
-
-    /* Set forwarding pointer (clobbers start of list). */
-    cons->car = 0x01;
-    cons->cdr = new_list_pointer;
-
-    /* Try to linearize the list in the cdr direction to help reduce
-     * paging. */
-    while (1) {
-       lispobj  new_cdr;
-       struct cons *cdr_cons, *new_cdr_cons;
-
-       if (LowtagOf(cdr) != type_ListPointer || !from_space_p(cdr)
-           || (*((lispobj *)PTR(cdr)) == 0x01))
-           break;
-
-       cdr_cons = (struct cons *) PTR(cdr);
-
-       /* Copy 'cdr'. */
-       new_cdr_cons = (struct cons*) gc_quick_alloc(sizeof(struct cons));
-       new_cdr_cons->car = cdr_cons->car;
-       new_cdr_cons->cdr = cdr_cons->cdr;
-       new_cdr = (lispobj)new_cdr_cons | LowtagOf(cdr);
-
-       /* Grab the cdr before it is clobbered. */
-       cdr = cdr_cons->cdr;
-
-       /* Set forwarding pointer. */
-       cdr_cons->car = 0x01;
-       cdr_cons->cdr = new_cdr;
-
-       /* Update the cdr of the last cons copied into new space to
-        * keep the newspace scavenge from having to do it. */
-       new_cons->cdr = new_cdr;
-
-       new_cons = new_cdr_cons;
-    }
-
-    return new_list_pointer;
-}
-
-\f
-/*
- * scavenging and transporting other pointers
- */
-
-static int
-scav_other_pointer(lispobj *where, lispobj object)
-{
-    lispobj first, *first_pointer;
-
-    gc_assert(Pointerp(object));
-
-    /* Object is a pointer into from space - not FP. */
-    first_pointer = (lispobj *) PTR(object);
-
-    first = (transother[TypeOf(*first_pointer)])(object);
-
-    if (first != object) {
-       /* Set forwarding pointer. */
-       first_pointer[0] = 0x01;
-       first_pointer[1] = first;
-       *where = first;
-    }
-
-    gc_assert(Pointerp(first));
-    gc_assert(!from_space_p(first));
-
-    return 1;
-}
-\f
-/*
- * immediate, boxed, and unboxed objects
- */
-
-static int
-size_pointer(lispobj *where)
-{
-    return 1;
-}
-
-static int
-scav_immediate(lispobj *where, lispobj object)
-{
-    return 1;
-}
-
-static lispobj
-trans_immediate(lispobj object)
-{
-    lose("trying to transport an immediate");
-    return NIL; /* bogus return value to satisfy static type checking */
-}
-
-static int
-size_immediate(lispobj *where)
-{
-    return 1;
-}
-
-
-static int
-scav_boxed(lispobj *where, lispobj object)
-{
-    return 1;
-}
-
-static lispobj
-trans_boxed(lispobj object)
-{
-    lispobj header;
-    unsigned long length;
-
-    gc_assert(Pointerp(object));
-
-    header = *((lispobj *) PTR(object));
-    length = HeaderValue(header) + 1;
-    length = CEILING(length, 2);
-
-    return copy_object(object, length);
-}
-
-static lispobj
-trans_boxed_large(lispobj object)
-{
-    lispobj header;
-    unsigned long length;
-
-    gc_assert(Pointerp(object));
-
-    header = *((lispobj *) PTR(object));
-    length = HeaderValue(header) + 1;
-    length = CEILING(length, 2);
-
-    return copy_large_object(object, length);
-}
-
-static int
-size_boxed(lispobj *where)
-{
-    lispobj header;
-    unsigned long length;
-
-    header = *where;
-    length = HeaderValue(header) + 1;
-    length = CEILING(length, 2);
-
-    return length;
-}
-
-static int
-scav_fdefn(lispobj *where, lispobj object)
-{
-    struct fdefn *fdefn;
-
-    fdefn = (struct fdefn *)where;
-
-    /* FSHOW((stderr, "scav_fdefn, function = %p, raw_addr = %p\n", 
-       fdefn->function, fdefn->raw_addr)); */
-
-    if ((char *)(fdefn->function + RAW_ADDR_OFFSET) == fdefn->raw_addr) {
-       scavenge(where + 1, sizeof(struct fdefn)/sizeof(lispobj) - 1);
-
-       /* Don't write unnecessarily. */
-       if (fdefn->raw_addr != (char *)(fdefn->function + RAW_ADDR_OFFSET))
-           fdefn->raw_addr = (char *)(fdefn->function + RAW_ADDR_OFFSET);
-
-       return sizeof(struct fdefn) / sizeof(lispobj);
-    } else {
-       return 1;
-    }
-}
-
-static int
-scav_unboxed(lispobj *where, lispobj object)
-{
-    unsigned long length;
-
-    length = HeaderValue(object) + 1;
-    length = CEILING(length, 2);
-
-    return length;
-}
-
-static lispobj
-trans_unboxed(lispobj object)
-{
-    lispobj header;
-    unsigned long length;
-
-
-    gc_assert(Pointerp(object));
-
-    header = *((lispobj *) PTR(object));
-    length = HeaderValue(header) + 1;
-    length = CEILING(length, 2);
-
-    return copy_unboxed_object(object, length);
-}
-
-static lispobj
-trans_unboxed_large(lispobj object)
-{
-    lispobj header;
-    unsigned long length;
-
-
-    gc_assert(Pointerp(object));
-
-    header = *((lispobj *) PTR(object));
-    length = HeaderValue(header) + 1;
-    length = CEILING(length, 2);
-
-    return copy_large_unboxed_object(object, length);
-}
-
-static int
-size_unboxed(lispobj *where)
-{
-    lispobj header;
-    unsigned long length;
-
-    header = *where;
-    length = HeaderValue(header) + 1;
-    length = CEILING(length, 2);
-
-    return length;
-}
-\f
-/*
- * vector-like objects
- */
-
-#define NWORDS(x,y) (CEILING((x),(y)) / (y))
-
-static int
-scav_string(lispobj *where, lispobj object)
-{
-    struct vector *vector;
-    int length, nwords;
-
-    /* NOTE: Strings contain one more byte of data than the length */
-    /* slot indicates. */
-
-    vector = (struct vector *) where;
-    length = fixnum_value(vector->length) + 1;
-    nwords = CEILING(NWORDS(length, 4) + 2, 2);
-
-    return nwords;
-}
-
-static lispobj
-trans_string(lispobj object)
-{
-    struct vector *vector;
-    int length, nwords;
-
-    gc_assert(Pointerp(object));
-
-    /* NOTE: A string contains one more byte of data (a terminating
-     * '\0' to help when interfacing with C functions) than indicated
-     * by the length slot. */
-
-    vector = (struct vector *) PTR(object);
-    length = fixnum_value(vector->length) + 1;
-    nwords = CEILING(NWORDS(length, 4) + 2, 2);
-
-    return copy_large_unboxed_object(object, nwords);
-}
-
-static int
-size_string(lispobj *where)
-{
-    struct vector *vector;
-    int length, nwords;
-
-    /* NOTE: A string contains one more byte of data (a terminating
-     * '\0' to help when interfacing with C functions) than indicated
-     * by the length slot. */
-
-    vector = (struct vector *) where;
-    length = fixnum_value(vector->length) + 1;
-    nwords = CEILING(NWORDS(length, 4) + 2, 2);
-
-    return nwords;
-}
-
-/* FIXME: What does this mean? */
-int gencgc_hash = 1;
-
-static int
-scav_vector(lispobj *where, lispobj object)
-{
-    unsigned int kv_length;
-    lispobj *kv_vector;
-    unsigned int length = 0; /* (0 = dummy to stop GCC warning) */
-    lispobj *hash_table;
-    lispobj empty_symbol;
-    unsigned int *index_vector = NULL; /* (NULL = dummy to stop GCC warning) */
-    unsigned int *next_vector = NULL; /* (NULL = dummy to stop GCC warning) */
-    unsigned int *hash_vector = NULL; /* (NULL = dummy to stop GCC warning) */
-    lispobj weak_p_obj;
-    unsigned next_vector_length = 0;
-
-    /* FIXME: A comment explaining this would be nice. It looks as
-     * though SB-VM:VECTOR-VALID-HASHING-SUBTYPE is set for EQ-based
-     * hash tables in the Lisp HASH-TABLE code, and nowhere else. */
-    if (HeaderValue(object) != subtype_VectorValidHashing)
-       return 1;
-
-    if (!gencgc_hash) {
-       /* This is set for backward compatibility. FIXME: Do we need
-        * this any more? */
-       *where = (subtype_VectorMustRehash << type_Bits) | type_SimpleVector;
-       return 1;
-    }
-
-    kv_length = fixnum_value(where[1]);
-    kv_vector = where + 2;  /* Skip the header and length. */
-    /*FSHOW((stderr,"/kv_length = %d\n", kv_length));*/
-
-    /* Scavenge element 0, which may be a hash-table structure. */
-    scavenge(where+2, 1);
-    if (!Pointerp(where[2])) {
-       lose("no pointer at %x in hash table", where[2]);
-    }
-    hash_table = (lispobj *)PTR(where[2]);
-    /*FSHOW((stderr,"/hash_table = %x\n", hash_table));*/
-    if (TypeOf(hash_table[0]) != type_InstanceHeader) {
-       lose("hash table not instance (%x at %x)", hash_table[0], hash_table);
-    }
-
-    /* Scavenge element 1, which should be some internal symbol that
-     * the hash table code reserves for marking empty slots. */
-    scavenge(where+3, 1);
-    if (!Pointerp(where[3])) {
-       lose("not empty-hash-table-slot symbol pointer: %x", where[3]);
-    }
-    empty_symbol = where[3];
-    /* fprintf(stderr,"* empty_symbol = %x\n", empty_symbol);*/
-    if (TypeOf(*(lispobj *)PTR(empty_symbol)) != type_SymbolHeader) {
-       lose("not a symbol where empty-hash-table-slot symbol expected: %x",
-            *(lispobj *)PTR(empty_symbol));
-    }
-
-    /* Scavenge hash table, which will fix the positions of the other
-     * needed objects. */
-    scavenge(hash_table, 16);
-
-    /* Cross-check the kv_vector. */
-    if (where != (lispobj *)PTR(hash_table[9])) {
-       lose("hash_table table!=this table %x", hash_table[9]);
+    /* Cross-check the kv_vector. */
+    if (where != (lispobj *)native_pointer(hash_table[9])) {
+       lose("hash_table table!=this table %x", hash_table[9]);
     }
 
     /* WEAK-P */
@@ -2792,11 +1913,12 @@ scav_vector(lispobj *where, lispobj object)
     {
        lispobj index_vector_obj = hash_table[13];
 
-       if (Pointerp(index_vector_obj) &&
-           (TypeOf(*(lispobj *)PTR(index_vector_obj)) == type_SimpleArrayUnsignedByte32)) {
-           index_vector = ((unsigned int *)PTR(index_vector_obj)) + 2;
+       if (is_lisp_pointer(index_vector_obj) &&
+           (widetag_of(*(lispobj *)native_pointer(index_vector_obj)) ==
+            SIMPLE_ARRAY_UNSIGNED_BYTE_32_WIDETAG)) {
+           index_vector = ((unsigned int *)native_pointer(index_vector_obj)) + 2;
            /*FSHOW((stderr, "/index_vector = %x\n",index_vector));*/
-           length = fixnum_value(((unsigned int *)PTR(index_vector_obj))[1]);
+           length = fixnum_value(((unsigned int *)native_pointer(index_vector_obj))[1]);
            /*FSHOW((stderr, "/length = %d\n", length));*/
        } else {
            lose("invalid index_vector %x", index_vector_obj);
@@ -2807,11 +1929,12 @@ scav_vector(lispobj *where, lispobj object)
     {
        lispobj next_vector_obj = hash_table[14];
 
-       if (Pointerp(next_vector_obj) &&
-           (TypeOf(*(lispobj *)PTR(next_vector_obj)) == type_SimpleArrayUnsignedByte32)) {
-           next_vector = ((unsigned int *)PTR(next_vector_obj)) + 2;
+       if (is_lisp_pointer(next_vector_obj) &&
+           (widetag_of(*(lispobj *)native_pointer(next_vector_obj)) ==
+            SIMPLE_ARRAY_UNSIGNED_BYTE_32_WIDETAG)) {
+           next_vector = ((unsigned int *)native_pointer(next_vector_obj)) + 2;
            /*FSHOW((stderr, "/next_vector = %x\n", next_vector));*/
-           next_vector_length = fixnum_value(((unsigned int *)PTR(next_vector_obj))[1]);
+           next_vector_length = fixnum_value(((unsigned int *)native_pointer(next_vector_obj))[1]);
            /*FSHOW((stderr, "/next_vector_length = %d\n", next_vector_length));*/
        } else {
            lose("invalid next_vector %x", next_vector_obj);
@@ -2826,12 +1949,12 @@ scav_vector(lispobj *where, lispobj object)
         * probably other stuff too. Ugh.. */
        lispobj hash_vector_obj = hash_table[15];
 
-       if (Pointerp(hash_vector_obj) &&
-           (TypeOf(*(lispobj *)PTR(hash_vector_obj))
-            == type_SimpleArrayUnsignedByte32)) {
-           hash_vector = ((unsigned int *)PTR(hash_vector_obj)) + 2;
+       if (is_lisp_pointer(hash_vector_obj) &&
+           (widetag_of(*(lispobj *)native_pointer(hash_vector_obj))
+            == SIMPLE_ARRAY_UNSIGNED_BYTE_32_WIDETAG)) {
+           hash_vector = ((unsigned int *)native_pointer(hash_vector_obj)) + 2;
            /*FSHOW((stderr, "/hash_vector = %x\n", hash_vector));*/
-           gc_assert(fixnum_value(((unsigned int *)PTR(hash_vector_obj))[1])
+           gc_assert(fixnum_value(((unsigned int *)native_pointer(hash_vector_obj))[1])
                      == next_vector_length);
        } else {
            hash_vector = NULL;
@@ -2904,559 +2027,25 @@ scav_vector(lispobj *where, lispobj object)
                                next = next_vector[next];
                            }
                        }
-                   }
-               }
-           }
-       }
-    }
-    return (CEILING(kv_length + 2, 2));
-}
-
-static lispobj
-trans_vector(lispobj object)
-{
-    struct vector *vector;
-    int length, nwords;
-
-    gc_assert(Pointerp(object));
-
-    vector = (struct vector *) PTR(object);
-
-    length = fixnum_value(vector->length);
-    nwords = CEILING(length + 2, 2);
-
-    return copy_large_object(object, nwords);
-}
-
-static int
-size_vector(lispobj *where)
-{
-    struct vector *vector;
-    int length, nwords;
-
-    vector = (struct vector *) where;
-    length = fixnum_value(vector->length);
-    nwords = CEILING(length + 2, 2);
-
-    return nwords;
-}
-
-
-static int
-scav_vector_bit(lispobj *where, lispobj object)
-{
-    struct vector *vector;
-    int length, nwords;
-
-    vector = (struct vector *) where;
-    length = fixnum_value(vector->length);
-    nwords = CEILING(NWORDS(length, 32) + 2, 2);
-
-    return nwords;
-}
-
-static lispobj
-trans_vector_bit(lispobj object)
-{
-    struct vector *vector;
-    int length, nwords;
-
-    gc_assert(Pointerp(object));
-
-    vector = (struct vector *) PTR(object);
-    length = fixnum_value(vector->length);
-    nwords = CEILING(NWORDS(length, 32) + 2, 2);
-
-    return copy_large_unboxed_object(object, nwords);
-}
-
-static int
-size_vector_bit(lispobj *where)
-{
-    struct vector *vector;
-    int length, nwords;
-
-    vector = (struct vector *) where;
-    length = fixnum_value(vector->length);
-    nwords = CEILING(NWORDS(length, 32) + 2, 2);
-
-    return nwords;
-}
-
-
-static int
-scav_vector_unsigned_byte_2(lispobj *where, lispobj object)
-{
-    struct vector *vector;
-    int length, nwords;
-
-    vector = (struct vector *) where;
-    length = fixnum_value(vector->length);
-    nwords = CEILING(NWORDS(length, 16) + 2, 2);
-
-    return nwords;
-}
-
-static lispobj
-trans_vector_unsigned_byte_2(lispobj object)
-{
-    struct vector *vector;
-    int length, nwords;
-
-    gc_assert(Pointerp(object));
-
-    vector = (struct vector *) PTR(object);
-    length = fixnum_value(vector->length);
-    nwords = CEILING(NWORDS(length, 16) + 2, 2);
-
-    return copy_large_unboxed_object(object, nwords);
-}
-
-static int
-size_vector_unsigned_byte_2(lispobj *where)
-{
-    struct vector *vector;
-    int length, nwords;
-
-    vector = (struct vector *) where;
-    length = fixnum_value(vector->length);
-    nwords = CEILING(NWORDS(length, 16) + 2, 2);
-
-    return nwords;
-}
-
-
-static int
-scav_vector_unsigned_byte_4(lispobj *where, lispobj object)
-{
-    struct vector *vector;
-    int length, nwords;
-
-    vector = (struct vector *) where;
-    length = fixnum_value(vector->length);
-    nwords = CEILING(NWORDS(length, 8) + 2, 2);
-
-    return nwords;
-}
-
-static lispobj
-trans_vector_unsigned_byte_4(lispobj object)
-{
-    struct vector *vector;
-    int length, nwords;
-
-    gc_assert(Pointerp(object));
-
-    vector = (struct vector *) PTR(object);
-    length = fixnum_value(vector->length);
-    nwords = CEILING(NWORDS(length, 8) + 2, 2);
-
-    return copy_large_unboxed_object(object, nwords);
-}
-
-static int
-size_vector_unsigned_byte_4(lispobj *where)
-{
-    struct vector *vector;
-    int length, nwords;
-
-    vector = (struct vector *) where;
-    length = fixnum_value(vector->length);
-    nwords = CEILING(NWORDS(length, 8) + 2, 2);
-
-    return nwords;
-}
-
-static int
-scav_vector_unsigned_byte_8(lispobj *where, lispobj object)
-{
-    struct vector *vector;
-    int length, nwords;
-
-    vector = (struct vector *) where;
-    length = fixnum_value(vector->length);
-    nwords = CEILING(NWORDS(length, 4) + 2, 2);
-
-    return nwords;
-}
-
-static lispobj
-trans_vector_unsigned_byte_8(lispobj object)
-{
-    struct vector *vector;
-    int length, nwords;
-
-    gc_assert(Pointerp(object));
-
-    vector = (struct vector *) PTR(object);
-    length = fixnum_value(vector->length);
-    nwords = CEILING(NWORDS(length, 4) + 2, 2);
-
-    return copy_large_unboxed_object(object, nwords);
-}
-
-static int
-size_vector_unsigned_byte_8(lispobj *where)
-{
-    struct vector *vector;
-    int length, nwords;
-
-    vector = (struct vector *) where;
-    length = fixnum_value(vector->length);
-    nwords = CEILING(NWORDS(length, 4) + 2, 2);
-
-    return nwords;
-}
-
-
-static int
-scav_vector_unsigned_byte_16(lispobj *where, lispobj object)
-{
-    struct vector *vector;
-    int length, nwords;
-
-    vector = (struct vector *) where;
-    length = fixnum_value(vector->length);
-    nwords = CEILING(NWORDS(length, 2) + 2, 2);
-
-    return nwords;
-}
-
-static lispobj
-trans_vector_unsigned_byte_16(lispobj object)
-{
-    struct vector *vector;
-    int length, nwords;
-
-    gc_assert(Pointerp(object));
-
-    vector = (struct vector *) PTR(object);
-    length = fixnum_value(vector->length);
-    nwords = CEILING(NWORDS(length, 2) + 2, 2);
-
-    return copy_large_unboxed_object(object, nwords);
-}
-
-static int
-size_vector_unsigned_byte_16(lispobj *where)
-{
-    struct vector *vector;
-    int length, nwords;
-
-    vector = (struct vector *) where;
-    length = fixnum_value(vector->length);
-    nwords = CEILING(NWORDS(length, 2) + 2, 2);
-
-    return nwords;
-}
-
-static int
-scav_vector_unsigned_byte_32(lispobj *where, lispobj object)
-{
-    struct vector *vector;
-    int length, nwords;
-
-    vector = (struct vector *) where;
-    length = fixnum_value(vector->length);
-    nwords = CEILING(length + 2, 2);
-
-    return nwords;
-}
-
-static lispobj
-trans_vector_unsigned_byte_32(lispobj object)
-{
-    struct vector *vector;
-    int length, nwords;
-
-    gc_assert(Pointerp(object));
-
-    vector = (struct vector *) PTR(object);
-    length = fixnum_value(vector->length);
-    nwords = CEILING(length + 2, 2);
-
-    return copy_large_unboxed_object(object, nwords);
-}
-
-static int
-size_vector_unsigned_byte_32(lispobj *where)
-{
-    struct vector *vector;
-    int length, nwords;
-
-    vector = (struct vector *) where;
-    length = fixnum_value(vector->length);
-    nwords = CEILING(length + 2, 2);
-
-    return nwords;
-}
-
-static int
-scav_vector_single_float(lispobj *where, lispobj object)
-{
-    struct vector *vector;
-    int length, nwords;
-
-    vector = (struct vector *) where;
-    length = fixnum_value(vector->length);
-    nwords = CEILING(length + 2, 2);
-
-    return nwords;
-}
-
-static lispobj
-trans_vector_single_float(lispobj object)
-{
-    struct vector *vector;
-    int length, nwords;
-
-    gc_assert(Pointerp(object));
-
-    vector = (struct vector *) PTR(object);
-    length = fixnum_value(vector->length);
-    nwords = CEILING(length + 2, 2);
-
-    return copy_large_unboxed_object(object, nwords);
-}
-
-static int
-size_vector_single_float(lispobj *where)
-{
-    struct vector *vector;
-    int length, nwords;
-
-    vector = (struct vector *) where;
-    length = fixnum_value(vector->length);
-    nwords = CEILING(length + 2, 2);
-
-    return nwords;
-}
-
-static int
-scav_vector_double_float(lispobj *where, lispobj object)
-{
-    struct vector *vector;
-    int length, nwords;
-
-    vector = (struct vector *) where;
-    length = fixnum_value(vector->length);
-    nwords = CEILING(length * 2 + 2, 2);
-
-    return nwords;
-}
-
-static lispobj
-trans_vector_double_float(lispobj object)
-{
-    struct vector *vector;
-    int length, nwords;
-
-    gc_assert(Pointerp(object));
-
-    vector = (struct vector *) PTR(object);
-    length = fixnum_value(vector->length);
-    nwords = CEILING(length * 2 + 2, 2);
-
-    return copy_large_unboxed_object(object, nwords);
-}
-
-static int
-size_vector_double_float(lispobj *where)
-{
-    struct vector *vector;
-    int length, nwords;
-
-    vector = (struct vector *) where;
-    length = fixnum_value(vector->length);
-    nwords = CEILING(length * 2 + 2, 2);
-
-    return nwords;
-}
-
-#ifdef type_SimpleArrayLongFloat
-static int
-scav_vector_long_float(lispobj *where, lispobj object)
-{
-    struct vector *vector;
-    int length, nwords;
-
-    vector = (struct vector *) where;
-    length = fixnum_value(vector->length);
-    nwords = CEILING(length * 3 + 2, 2);
-
-    return nwords;
-}
-
-static lispobj
-trans_vector_long_float(lispobj object)
-{
-    struct vector *vector;
-    int length, nwords;
-
-    gc_assert(Pointerp(object));
-
-    vector = (struct vector *) PTR(object);
-    length = fixnum_value(vector->length);
-    nwords = CEILING(length * 3 + 2, 2);
-
-    return copy_large_unboxed_object(object, nwords);
-}
-
-static int
-size_vector_long_float(lispobj *where)
-{
-    struct vector *vector;
-    int length, nwords;
-
-    vector = (struct vector *) where;
-    length = fixnum_value(vector->length);
-    nwords = CEILING(length * 3 + 2, 2);
-
-    return nwords;
-}
-#endif
-
-
-#ifdef type_SimpleArrayComplexSingleFloat
-static int
-scav_vector_complex_single_float(lispobj *where, lispobj object)
-{
-    struct vector *vector;
-    int length, nwords;
-
-    vector = (struct vector *) where;
-    length = fixnum_value(vector->length);
-    nwords = CEILING(length * 2 + 2, 2);
-
-    return nwords;
-}
-
-static lispobj
-trans_vector_complex_single_float(lispobj object)
-{
-    struct vector *vector;
-    int length, nwords;
-
-    gc_assert(Pointerp(object));
-
-    vector = (struct vector *) PTR(object);
-    length = fixnum_value(vector->length);
-    nwords = CEILING(length * 2 + 2, 2);
-
-    return copy_large_unboxed_object(object, nwords);
-}
-
-static int
-size_vector_complex_single_float(lispobj *where)
-{
-    struct vector *vector;
-    int length, nwords;
-
-    vector = (struct vector *) where;
-    length = fixnum_value(vector->length);
-    nwords = CEILING(length * 2 + 2, 2);
-
-    return nwords;
-}
-#endif
-
-#ifdef type_SimpleArrayComplexDoubleFloat
-static int
-scav_vector_complex_double_float(lispobj *where, lispobj object)
-{
-    struct vector *vector;
-    int length, nwords;
-
-    vector = (struct vector *) where;
-    length = fixnum_value(vector->length);
-    nwords = CEILING(length * 4 + 2, 2);
-
-    return nwords;
-}
-
-static lispobj
-trans_vector_complex_double_float(lispobj object)
-{
-    struct vector *vector;
-    int length, nwords;
-
-    gc_assert(Pointerp(object));
-
-    vector = (struct vector *) PTR(object);
-    length = fixnum_value(vector->length);
-    nwords = CEILING(length * 4 + 2, 2);
-
-    return copy_large_unboxed_object(object, nwords);
-}
-
-static int
-size_vector_complex_double_float(lispobj *where)
-{
-    struct vector *vector;
-    int length, nwords;
-
-    vector = (struct vector *) where;
-    length = fixnum_value(vector->length);
-    nwords = CEILING(length * 4 + 2, 2);
-
-    return nwords;
-}
-#endif
-
-
-#ifdef type_SimpleArrayComplexLongFloat
-static int
-scav_vector_complex_long_float(lispobj *where, lispobj object)
-{
-    struct vector *vector;
-    int length, nwords;
-
-    vector = (struct vector *) where;
-    length = fixnum_value(vector->length);
-    nwords = CEILING(length * 6 + 2, 2);
-
-    return nwords;
-}
-
-static lispobj
-trans_vector_complex_long_float(lispobj object)
-{
-    struct vector *vector;
-    int length, nwords;
-
-    gc_assert(Pointerp(object));
-
-    vector = (struct vector *) PTR(object);
-    length = fixnum_value(vector->length);
-    nwords = CEILING(length * 6 + 2, 2);
-
-    return copy_large_unboxed_object(object, nwords);
+                   }
+               }
+           }
+       }
+    }
+    return (CEILING(kv_length + 2, 2));
 }
 
-static int
-size_vector_complex_long_float(lispobj *where)
-{
-    struct vector *vector;
-    int length, nwords;
-
-    vector = (struct vector *) where;
-    length = fixnum_value(vector->length);
-    nwords = CEILING(length * 6 + 2, 2);
-
-    return nwords;
-}
-#endif
 
 \f
 /*
  * weak pointers
  */
 
-/* XX This is a hack adapted from cgc.c. These don't work too well with the
- * gencgc as a list of the weak pointers is maintained within the
- * objects which causes writes to the pages. A limited attempt is made
- * to avoid unnecessary writes, but this needs a re-think. */
-
+/* XX This is a hack adapted from cgc.c. These don't work too
+ * efficiently with the gencgc as a list of the weak pointers is
+ * maintained within the objects which causes writes to the pages. A
+ * limited attempt is made to avoid unnecessary writes, but this needs
+ * a re-think. */
 #define WEAK_POINTER_NWORDS \
     CEILING((sizeof(struct weak_pointer) / sizeof(lispobj)), 2)
 
@@ -3494,363 +2083,6 @@ scav_weak_pointer(lispobj *where, lispobj object)
     return WEAK_POINTER_NWORDS;
 }
 
-static lispobj
-trans_weak_pointer(lispobj object)
-{
-    lispobj copy;
-    /* struct weak_pointer *wp; */
-
-    gc_assert(Pointerp(object));
-
-#if defined(DEBUG_WEAK)
-    FSHOW((stderr, "Transporting weak pointer from 0x%08x\n", object));
-#endif
-
-    /* Need to remember where all the weak pointers are that have */
-    /* been transported so they can be fixed up in a post-GC pass. */
-
-    copy = copy_object(object, WEAK_POINTER_NWORDS);
-    /*  wp = (struct weak_pointer *) PTR(copy);*/
-       
-
-    /* Push the weak pointer onto the list of weak pointers. */
-    /*  wp->next = weak_pointers;
-     * weak_pointers = wp;*/
-
-    return copy;
-}
-
-static int
-size_weak_pointer(lispobj *where)
-{
-    return WEAK_POINTER_NWORDS;
-}
-
-void scan_weak_pointers(void)
-{
-    struct weak_pointer *wp;
-    for (wp = weak_pointers; wp != NULL; wp = wp->next) {
-       lispobj value = wp->value;
-       lispobj *first_pointer;
-
-       first_pointer = (lispobj *)PTR(value);
-
-       /*
-       FSHOW((stderr, "/weak pointer at 0x%08x\n", (unsigned long) wp));
-       FSHOW((stderr, "/value: 0x%08x\n", (unsigned long) value));
-       */
-
-       if (Pointerp(value) && from_space_p(value)) {
-           /* Now, we need to check whether the object has been forwarded. If
-            * it has been, the weak pointer is still good and needs to be
-            * updated. Otherwise, the weak pointer needs to be nil'ed
-            * out. */
-           if (first_pointer[0] == 0x01) {
-               wp->value = first_pointer[1];
-           } else {
-               /* Break it. */
-               SHOW("broken");
-               wp->value = NIL;
-               wp->broken = T;
-           }
-       }
-    }
-}
-\f
-/*
- * initialization
- */
-
-static int
-scav_lose(lispobj *where, lispobj object)
-{
-    lose("no scavenge function for object 0x%08x", (unsigned long) object);
-    return 0; /* bogus return value to satisfy static type checking */
-}
-
-static lispobj
-trans_lose(lispobj object)
-{
-    lose("no transport function for object 0x%08x", (unsigned long) object);
-    return NIL; /* bogus return value to satisfy static type checking */
-}
-
-static int
-size_lose(lispobj *where)
-{
-    lose("no size function for object at 0x%08x", (unsigned long) where);
-    return 1; /* bogus return value to satisfy static type checking */
-}
-
-static void
-gc_init_tables(void)
-{
-    int i;
-
-    /* Set default value in all slots of scavenge table. */
-    for (i = 0; i < 256; i++) { /* FIXME: bare constant length, ick! */
-       scavtab[i] = scav_lose;
-    }
-
-    /* For each type which can be selected by the low 3 bits of the tag
-     * alone, set multiple entries in our 8-bit scavenge table (one for each
-     * possible value of the high 5 bits). */
-    for (i = 0; i < 32; i++) { /* FIXME: bare constant length, ick! */
-       scavtab[type_EvenFixnum|(i<<3)] = scav_immediate;
-       scavtab[type_FunctionPointer|(i<<3)] = scav_function_pointer;
-       /* OtherImmediate0 */
-       scavtab[type_ListPointer|(i<<3)] = scav_list_pointer;
-       scavtab[type_OddFixnum|(i<<3)] = scav_immediate;
-       scavtab[type_InstancePointer|(i<<3)] = scav_instance_pointer;
-       /* OtherImmediate1 */
-       scavtab[type_OtherPointer|(i<<3)] = scav_other_pointer;
-    }
-
-    /* Other-pointer types (those selected by all eight bits of the tag) get
-     * one entry each in the scavenge table. */
-    scavtab[type_Bignum] = scav_unboxed;
-    scavtab[type_Ratio] = scav_boxed;
-    scavtab[type_SingleFloat] = scav_unboxed;
-    scavtab[type_DoubleFloat] = scav_unboxed;
-#ifdef type_LongFloat
-    scavtab[type_LongFloat] = scav_unboxed;
-#endif
-    scavtab[type_Complex] = scav_boxed;
-#ifdef type_ComplexSingleFloat
-    scavtab[type_ComplexSingleFloat] = scav_unboxed;
-#endif
-#ifdef type_ComplexDoubleFloat
-    scavtab[type_ComplexDoubleFloat] = scav_unboxed;
-#endif
-#ifdef type_ComplexLongFloat
-    scavtab[type_ComplexLongFloat] = scav_unboxed;
-#endif
-    scavtab[type_SimpleArray] = scav_boxed;
-    scavtab[type_SimpleString] = scav_string;
-    scavtab[type_SimpleBitVector] = scav_vector_bit;
-    scavtab[type_SimpleVector] = scav_vector;
-    scavtab[type_SimpleArrayUnsignedByte2] = scav_vector_unsigned_byte_2;
-    scavtab[type_SimpleArrayUnsignedByte4] = scav_vector_unsigned_byte_4;
-    scavtab[type_SimpleArrayUnsignedByte8] = scav_vector_unsigned_byte_8;
-    scavtab[type_SimpleArrayUnsignedByte16] = scav_vector_unsigned_byte_16;
-    scavtab[type_SimpleArrayUnsignedByte32] = scav_vector_unsigned_byte_32;
-#ifdef type_SimpleArraySignedByte8
-    scavtab[type_SimpleArraySignedByte8] = scav_vector_unsigned_byte_8;
-#endif
-#ifdef type_SimpleArraySignedByte16
-    scavtab[type_SimpleArraySignedByte16] = scav_vector_unsigned_byte_16;
-#endif
-#ifdef type_SimpleArraySignedByte30
-    scavtab[type_SimpleArraySignedByte30] = scav_vector_unsigned_byte_32;
-#endif
-#ifdef type_SimpleArraySignedByte32
-    scavtab[type_SimpleArraySignedByte32] = scav_vector_unsigned_byte_32;
-#endif
-    scavtab[type_SimpleArraySingleFloat] = scav_vector_single_float;
-    scavtab[type_SimpleArrayDoubleFloat] = scav_vector_double_float;
-#ifdef type_SimpleArrayLongFloat
-    scavtab[type_SimpleArrayLongFloat] = scav_vector_long_float;
-#endif
-#ifdef type_SimpleArrayComplexSingleFloat
-    scavtab[type_SimpleArrayComplexSingleFloat] = scav_vector_complex_single_float;
-#endif
-#ifdef type_SimpleArrayComplexDoubleFloat
-    scavtab[type_SimpleArrayComplexDoubleFloat] = scav_vector_complex_double_float;
-#endif
-#ifdef type_SimpleArrayComplexLongFloat
-    scavtab[type_SimpleArrayComplexLongFloat] = scav_vector_complex_long_float;
-#endif
-    scavtab[type_ComplexString] = scav_boxed;
-    scavtab[type_ComplexBitVector] = scav_boxed;
-    scavtab[type_ComplexVector] = scav_boxed;
-    scavtab[type_ComplexArray] = scav_boxed;
-    scavtab[type_CodeHeader] = scav_code_header;
-    /*scavtab[type_FunctionHeader] = scav_function_header;*/
-    /*scavtab[type_ClosureFunctionHeader] = scav_function_header;*/
-    /*scavtab[type_ReturnPcHeader] = scav_return_pc_header;*/
-#ifdef __i386__
-    scavtab[type_ClosureHeader] = scav_closure_header;
-    scavtab[type_FuncallableInstanceHeader] = scav_closure_header;
-    scavtab[type_ByteCodeFunction] = scav_closure_header;
-    scavtab[type_ByteCodeClosure] = scav_closure_header;
-#else
-    scavtab[type_ClosureHeader] = scav_boxed;
-    scavtab[type_FuncallableInstanceHeader] = scav_boxed;
-    scavtab[type_ByteCodeFunction] = scav_boxed;
-    scavtab[type_ByteCodeClosure] = scav_boxed;
-#endif
-    scavtab[type_ValueCellHeader] = scav_boxed;
-    scavtab[type_SymbolHeader] = scav_boxed;
-    scavtab[type_BaseChar] = scav_immediate;
-    scavtab[type_Sap] = scav_unboxed;
-    scavtab[type_UnboundMarker] = scav_immediate;
-    scavtab[type_WeakPointer] = scav_weak_pointer;
-    scavtab[type_InstanceHeader] = scav_boxed;
-    scavtab[type_Fdefn] = scav_fdefn;
-
-    /* transport other table, initialized same way as scavtab */
-    for (i = 0; i < 256; i++)
-       transother[i] = trans_lose;
-    transother[type_Bignum] = trans_unboxed;
-    transother[type_Ratio] = trans_boxed;
-    transother[type_SingleFloat] = trans_unboxed;
-    transother[type_DoubleFloat] = trans_unboxed;
-#ifdef type_LongFloat
-    transother[type_LongFloat] = trans_unboxed;
-#endif
-    transother[type_Complex] = trans_boxed;
-#ifdef type_ComplexSingleFloat
-    transother[type_ComplexSingleFloat] = trans_unboxed;
-#endif
-#ifdef type_ComplexDoubleFloat
-    transother[type_ComplexDoubleFloat] = trans_unboxed;
-#endif
-#ifdef type_ComplexLongFloat
-    transother[type_ComplexLongFloat] = trans_unboxed;
-#endif
-    transother[type_SimpleArray] = trans_boxed_large;
-    transother[type_SimpleString] = trans_string;
-    transother[type_SimpleBitVector] = trans_vector_bit;
-    transother[type_SimpleVector] = trans_vector;
-    transother[type_SimpleArrayUnsignedByte2] = trans_vector_unsigned_byte_2;
-    transother[type_SimpleArrayUnsignedByte4] = trans_vector_unsigned_byte_4;
-    transother[type_SimpleArrayUnsignedByte8] = trans_vector_unsigned_byte_8;
-    transother[type_SimpleArrayUnsignedByte16] = trans_vector_unsigned_byte_16;
-    transother[type_SimpleArrayUnsignedByte32] = trans_vector_unsigned_byte_32;
-#ifdef type_SimpleArraySignedByte8
-    transother[type_SimpleArraySignedByte8] = trans_vector_unsigned_byte_8;
-#endif
-#ifdef type_SimpleArraySignedByte16
-    transother[type_SimpleArraySignedByte16] = trans_vector_unsigned_byte_16;
-#endif
-#ifdef type_SimpleArraySignedByte30
-    transother[type_SimpleArraySignedByte30] = trans_vector_unsigned_byte_32;
-#endif
-#ifdef type_SimpleArraySignedByte32
-    transother[type_SimpleArraySignedByte32] = trans_vector_unsigned_byte_32;
-#endif
-    transother[type_SimpleArraySingleFloat] = trans_vector_single_float;
-    transother[type_SimpleArrayDoubleFloat] = trans_vector_double_float;
-#ifdef type_SimpleArrayLongFloat
-    transother[type_SimpleArrayLongFloat] = trans_vector_long_float;
-#endif
-#ifdef type_SimpleArrayComplexSingleFloat
-    transother[type_SimpleArrayComplexSingleFloat] = trans_vector_complex_single_float;
-#endif
-#ifdef type_SimpleArrayComplexDoubleFloat
-    transother[type_SimpleArrayComplexDoubleFloat] = trans_vector_complex_double_float;
-#endif
-#ifdef type_SimpleArrayComplexLongFloat
-    transother[type_SimpleArrayComplexLongFloat] = trans_vector_complex_long_float;
-#endif
-    transother[type_ComplexString] = trans_boxed;
-    transother[type_ComplexBitVector] = trans_boxed;
-    transother[type_ComplexVector] = trans_boxed;
-    transother[type_ComplexArray] = trans_boxed;
-    transother[type_CodeHeader] = trans_code_header;
-    transother[type_FunctionHeader] = trans_function_header;
-    transother[type_ClosureFunctionHeader] = trans_function_header;
-    transother[type_ReturnPcHeader] = trans_return_pc_header;
-    transother[type_ClosureHeader] = trans_boxed;
-    transother[type_FuncallableInstanceHeader] = trans_boxed;
-    transother[type_ByteCodeFunction] = trans_boxed;
-    transother[type_ByteCodeClosure] = trans_boxed;
-    transother[type_ValueCellHeader] = trans_boxed;
-    transother[type_SymbolHeader] = trans_boxed;
-    transother[type_BaseChar] = trans_immediate;
-    transother[type_Sap] = trans_unboxed;
-    transother[type_UnboundMarker] = trans_immediate;
-    transother[type_WeakPointer] = trans_weak_pointer;
-    transother[type_InstanceHeader] = trans_boxed;
-    transother[type_Fdefn] = trans_boxed;
-
-    /* size table, initialized the same way as scavtab */
-    for (i = 0; i < 256; i++)
-       sizetab[i] = size_lose;
-    for (i = 0; i < 32; i++) {
-       sizetab[type_EvenFixnum|(i<<3)] = size_immediate;
-       sizetab[type_FunctionPointer|(i<<3)] = size_pointer;
-       /* OtherImmediate0 */
-       sizetab[type_ListPointer|(i<<3)] = size_pointer;
-       sizetab[type_OddFixnum|(i<<3)] = size_immediate;
-       sizetab[type_InstancePointer|(i<<3)] = size_pointer;
-       /* OtherImmediate1 */
-       sizetab[type_OtherPointer|(i<<3)] = size_pointer;
-    }
-    sizetab[type_Bignum] = size_unboxed;
-    sizetab[type_Ratio] = size_boxed;
-    sizetab[type_SingleFloat] = size_unboxed;
-    sizetab[type_DoubleFloat] = size_unboxed;
-#ifdef type_LongFloat
-    sizetab[type_LongFloat] = size_unboxed;
-#endif
-    sizetab[type_Complex] = size_boxed;
-#ifdef type_ComplexSingleFloat
-    sizetab[type_ComplexSingleFloat] = size_unboxed;
-#endif
-#ifdef type_ComplexDoubleFloat
-    sizetab[type_ComplexDoubleFloat] = size_unboxed;
-#endif
-#ifdef type_ComplexLongFloat
-    sizetab[type_ComplexLongFloat] = size_unboxed;
-#endif
-    sizetab[type_SimpleArray] = size_boxed;
-    sizetab[type_SimpleString] = size_string;
-    sizetab[type_SimpleBitVector] = size_vector_bit;
-    sizetab[type_SimpleVector] = size_vector;
-    sizetab[type_SimpleArrayUnsignedByte2] = size_vector_unsigned_byte_2;
-    sizetab[type_SimpleArrayUnsignedByte4] = size_vector_unsigned_byte_4;
-    sizetab[type_SimpleArrayUnsignedByte8] = size_vector_unsigned_byte_8;
-    sizetab[type_SimpleArrayUnsignedByte16] = size_vector_unsigned_byte_16;
-    sizetab[type_SimpleArrayUnsignedByte32] = size_vector_unsigned_byte_32;
-#ifdef type_SimpleArraySignedByte8
-    sizetab[type_SimpleArraySignedByte8] = size_vector_unsigned_byte_8;
-#endif
-#ifdef type_SimpleArraySignedByte16
-    sizetab[type_SimpleArraySignedByte16] = size_vector_unsigned_byte_16;
-#endif
-#ifdef type_SimpleArraySignedByte30
-    sizetab[type_SimpleArraySignedByte30] = size_vector_unsigned_byte_32;
-#endif
-#ifdef type_SimpleArraySignedByte32
-    sizetab[type_SimpleArraySignedByte32] = size_vector_unsigned_byte_32;
-#endif
-    sizetab[type_SimpleArraySingleFloat] = size_vector_single_float;
-    sizetab[type_SimpleArrayDoubleFloat] = size_vector_double_float;
-#ifdef type_SimpleArrayLongFloat
-    sizetab[type_SimpleArrayLongFloat] = size_vector_long_float;
-#endif
-#ifdef type_SimpleArrayComplexSingleFloat
-    sizetab[type_SimpleArrayComplexSingleFloat] = size_vector_complex_single_float;
-#endif
-#ifdef type_SimpleArrayComplexDoubleFloat
-    sizetab[type_SimpleArrayComplexDoubleFloat] = size_vector_complex_double_float;
-#endif
-#ifdef type_SimpleArrayComplexLongFloat
-    sizetab[type_SimpleArrayComplexLongFloat] = size_vector_complex_long_float;
-#endif
-    sizetab[type_ComplexString] = size_boxed;
-    sizetab[type_ComplexBitVector] = size_boxed;
-    sizetab[type_ComplexVector] = size_boxed;
-    sizetab[type_ComplexArray] = size_boxed;
-    sizetab[type_CodeHeader] = size_code_header;
-#if 0
-    /* We shouldn't see these, so just lose if it happens. */
-    sizetab[type_FunctionHeader] = size_function_header;
-    sizetab[type_ClosureFunctionHeader] = size_function_header;
-    sizetab[type_ReturnPcHeader] = size_return_pc_header;
-#endif
-    sizetab[type_ClosureHeader] = size_boxed;
-    sizetab[type_FuncallableInstanceHeader] = size_boxed;
-    sizetab[type_ValueCellHeader] = size_boxed;
-    sizetab[type_SymbolHeader] = size_boxed;
-    sizetab[type_BaseChar] = size_immediate;
-    sizetab[type_Sap] = size_unboxed;
-    sizetab[type_UnboundMarker] = size_immediate;
-    sizetab[type_WeakPointer] = size_weak_pointer;
-    sizetab[type_InstanceHeader] = size_boxed;
-    sizetab[type_Fdefn] = size_boxed;
-}
 \f
 /* Scan an area looking for an object which encloses the given pointer.
  * Return the object start on success or NULL on failure. */
@@ -3862,13 +2094,13 @@ search_space(lispobj *start, size_t words, lispobj *pointer)
        lispobj thing = *start;
 
        /* If thing is an immediate then this is a cons. */
-       if (Pointerp(thing)
+       if (is_lisp_pointer(thing)
            || ((thing & 3) == 0) /* fixnum */
-           || (TypeOf(thing) == type_BaseChar)
-           || (TypeOf(thing) == type_UnboundMarker))
+           || (widetag_of(thing) == BASE_CHAR_WIDETAG)
+           || (widetag_of(thing) == UNBOUND_MARKER_WIDETAG))
            count = 2;
        else
-           count = (sizetab[TypeOf(thing)])(start);
+           count = (sizetab[widetag_of(thing)])(start);
 
        /* Check whether the pointer is within this object. */
        if ((pointer >= start) && (pointer < (start+count))) {
@@ -3890,7 +2122,7 @@ static lispobj*
 search_read_only_space(lispobj *pointer)
 {
     lispobj* start = (lispobj*)READ_ONLY_SPACE_START;
-    lispobj* end = (lispobj*)SymbolValue(READ_ONLY_SPACE_FREE_POINTER);
+    lispobj* end = (lispobj*)SymbolValue(READ_ONLY_SPACE_FREE_POINTER,0);
     if ((pointer < start) || (pointer >= end))
        return NULL;
     return (search_space(start, (pointer+2)-start, pointer));
@@ -3900,7 +2132,7 @@ static lispobj *
 search_static_space(lispobj *pointer)
 {
     lispobj* start = (lispobj*)STATIC_SPACE_START;
-    lispobj* end = (lispobj*)SymbolValue(STATIC_SPACE_FREE_POINTER);
+    lispobj* end = (lispobj*)SymbolValue(STATIC_SPACE_FREE_POINTER,0);
     if ((pointer < start) || (pointer >= end))
        return NULL;
     return (search_space(start, (pointer+2)-start, pointer));
@@ -3924,7 +2156,8 @@ search_dynamic_space(lispobj *pointer)
 
 /* Is there any possibility that pointer is a valid Lisp object
  * reference, and/or something else (e.g. subroutine call return
- * address) which should prevent us from moving the referred-to thing? */
+ * address) which should prevent us from moving the referred-to thing?
+ * This is called from preserve_pointers() */
 static int
 possibly_valid_dynamic_space_pointer(lispobj *pointer)
 {
@@ -3938,33 +2171,32 @@ possibly_valid_dynamic_space_pointer(lispobj *pointer)
     /* We need to allow raw pointers into Code objects for return
      * addresses. This will also pick up pointers to functions in code
      * objects. */
-    if (TypeOf(*start_addr) == type_CodeHeader) {
+    if (widetag_of(*start_addr) == CODE_HEADER_WIDETAG) {
        /* XXX could do some further checks here */
        return 1;
     }
 
     /* If it's not a return address then it needs to be a valid Lisp
      * pointer. */
-    if (!Pointerp((lispobj)pointer)) {
+    if (!is_lisp_pointer((lispobj)pointer)) {
        return 0;
     }
 
     /* Check that the object pointed to is consistent with the pointer
-     * low tag. */
-    switch (LowtagOf((lispobj)pointer)) {
-    case type_FunctionPointer:
+     * low tag.
+     */
+    switch (lowtag_of((lispobj)pointer)) {
+    case FUN_POINTER_LOWTAG:
        /* Start_addr should be the enclosing code object, or a closure
         * header. */
-       switch (TypeOf(*start_addr)) {
-       case type_CodeHeader:
+       switch (widetag_of(*start_addr)) {
+       case CODE_HEADER_WIDETAG:
            /* This case is probably caught above. */
            break;
-       case type_ClosureHeader:
-       case type_FuncallableInstanceHeader:
-       case type_ByteCodeFunction:
-       case type_ByteCodeClosure:
+       case CLOSURE_HEADER_WIDETAG:
+       case FUNCALLABLE_INSTANCE_HEADER_WIDETAG:
            if ((unsigned)pointer !=
-               ((unsigned)start_addr+type_FunctionPointer)) {
+               ((unsigned)start_addr+FUN_POINTER_LOWTAG)) {
                if (gencgc_verbose)
                    FSHOW((stderr,
                           "/Wf2: %x %x %x\n",
@@ -3980,9 +2212,9 @@ possibly_valid_dynamic_space_pointer(lispobj *pointer)
            return 0;
        }
        break;
-    case type_ListPointer:
+    case LIST_POINTER_LOWTAG:
        if ((unsigned)pointer !=
-           ((unsigned)start_addr+type_ListPointer)) {
+           ((unsigned)start_addr+LIST_POINTER_LOWTAG)) {
            if (gencgc_verbose)
                FSHOW((stderr,
                       "/Wl1: %x %x %x\n",
@@ -3990,14 +2222,14 @@ possibly_valid_dynamic_space_pointer(lispobj *pointer)
            return 0;
        }
        /* Is it plausible cons? */
-       if ((Pointerp(start_addr[0])
+       if ((is_lisp_pointer(start_addr[0])
            || ((start_addr[0] & 3) == 0) /* fixnum */
-           || (TypeOf(start_addr[0]) == type_BaseChar)
-           || (TypeOf(start_addr[0]) == type_UnboundMarker))
-          && (Pointerp(start_addr[1])
+           || (widetag_of(start_addr[0]) == BASE_CHAR_WIDETAG)
+           || (widetag_of(start_addr[0]) == UNBOUND_MARKER_WIDETAG))
+          && (is_lisp_pointer(start_addr[1])
               || ((start_addr[1] & 3) == 0) /* fixnum */
-              || (TypeOf(start_addr[1]) == type_BaseChar)
-              || (TypeOf(start_addr[1]) == type_UnboundMarker)))
+              || (widetag_of(start_addr[1]) == BASE_CHAR_WIDETAG)
+              || (widetag_of(start_addr[1]) == UNBOUND_MARKER_WIDETAG)))
            break;
        else {
            if (gencgc_verbose)
@@ -4006,16 +2238,16 @@ possibly_valid_dynamic_space_pointer(lispobj *pointer)
                       pointer, start_addr, *start_addr));
            return 0;
        }
-    case type_InstancePointer:
+    case INSTANCE_POINTER_LOWTAG:
        if ((unsigned)pointer !=
-           ((unsigned)start_addr+type_InstancePointer)) {
+           ((unsigned)start_addr+INSTANCE_POINTER_LOWTAG)) {
            if (gencgc_verbose)
                FSHOW((stderr,
                       "/Wi1: %x %x %x\n",
                       pointer, start_addr, *start_addr));
            return 0;
        }
-       if (TypeOf(start_addr[0]) != type_InstanceHeader) {
+       if (widetag_of(start_addr[0]) != INSTANCE_HEADER_WIDETAG) {
            if (gencgc_verbose)
                FSHOW((stderr,
                       "/Wi2: %x %x %x\n",
@@ -4023,9 +2255,9 @@ possibly_valid_dynamic_space_pointer(lispobj *pointer)
            return 0;
        }
        break;
-    case type_OtherPointer:
+    case OTHER_POINTER_LOWTAG:
        if ((unsigned)pointer !=
-           ((int)start_addr+type_OtherPointer)) {
+           ((int)start_addr+OTHER_POINTER_LOWTAG)) {
            if (gencgc_verbose)
                FSHOW((stderr,
                       "/Wo1: %x %x %x\n",
@@ -4033,16 +2265,16 @@ possibly_valid_dynamic_space_pointer(lispobj *pointer)
            return 0;
        }
        /* Is it plausible?  Not a cons. XXX should check the headers. */
-       if (Pointerp(start_addr[0]) || ((start_addr[0] & 3) == 0)) {
+       if (is_lisp_pointer(start_addr[0]) || ((start_addr[0] & 3) == 0)) {
            if (gencgc_verbose)
                FSHOW((stderr,
                       "/Wo2: %x %x %x\n",
                       pointer, start_addr, *start_addr));
            return 0;
        }
-       switch (TypeOf(start_addr[0])) {
-       case type_UnboundMarker:
-       case type_BaseChar:
+       switch (widetag_of(start_addr[0])) {
+       case UNBOUND_MARKER_WIDETAG:
+       case BASE_CHAR_WIDETAG:
            if (gencgc_verbose)
                FSHOW((stderr,
                       "*Wo3: %x %x %x\n",
@@ -4050,17 +2282,15 @@ possibly_valid_dynamic_space_pointer(lispobj *pointer)
            return 0;
 
            /* only pointed to by function pointers? */
-       case type_ClosureHeader:
-       case type_FuncallableInstanceHeader:
-       case type_ByteCodeFunction:
-       case type_ByteCodeClosure:
+       case CLOSURE_HEADER_WIDETAG:
+       case FUNCALLABLE_INSTANCE_HEADER_WIDETAG:
            if (gencgc_verbose)
                FSHOW((stderr,
                       "*Wo4: %x %x %x\n",
                       pointer, start_addr, *start_addr));
            return 0;
 
-       case type_InstanceHeader:
+       case INSTANCE_HEADER_WIDETAG:
            if (gencgc_verbose)
                FSHOW((stderr,
                       "*Wo5: %x %x %x\n",
@@ -4068,68 +2298,74 @@ possibly_valid_dynamic_space_pointer(lispobj *pointer)
            return 0;
 
            /* the valid other immediate pointer objects */
-       case type_SimpleVector:
-       case type_Ratio:
-       case type_Complex:
-#ifdef type_ComplexSingleFloat
-       case type_ComplexSingleFloat:
+       case SIMPLE_VECTOR_WIDETAG:
+       case RATIO_WIDETAG:
+       case COMPLEX_WIDETAG:
+#ifdef COMPLEX_SINGLE_FLOAT_WIDETAG
+       case COMPLEX_SINGLE_FLOAT_WIDETAG:
 #endif
-#ifdef type_ComplexDoubleFloat
-       case type_ComplexDoubleFloat:
+#ifdef COMPLEX_DOUBLE_FLOAT_WIDETAG
+       case COMPLEX_DOUBLE_FLOAT_WIDETAG:
 #endif
-#ifdef type_ComplexLongFloat
-       case type_ComplexLongFloat:
+#ifdef COMPLEX_LONG_FLOAT_WIDETAG
+       case COMPLEX_LONG_FLOAT_WIDETAG:
 #endif
-       case type_SimpleArray:
-       case type_ComplexString:
-       case type_ComplexBitVector:
-       case type_ComplexVector:
-       case type_ComplexArray:
-       case type_ValueCellHeader:
-       case type_SymbolHeader:
-       case type_Fdefn:
-       case type_CodeHeader:
-       case type_Bignum:
-       case type_SingleFloat:
-       case type_DoubleFloat:
-#ifdef type_LongFloat
-       case type_LongFloat:
+       case SIMPLE_ARRAY_WIDETAG:
+       case COMPLEX_BASE_STRING_WIDETAG:
+       case COMPLEX_VECTOR_NIL_WIDETAG:
+       case COMPLEX_BIT_VECTOR_WIDETAG:
+       case COMPLEX_VECTOR_WIDETAG:
+       case COMPLEX_ARRAY_WIDETAG:
+       case VALUE_CELL_HEADER_WIDETAG:
+       case SYMBOL_HEADER_WIDETAG:
+       case FDEFN_WIDETAG:
+       case CODE_HEADER_WIDETAG:
+       case BIGNUM_WIDETAG:
+       case SINGLE_FLOAT_WIDETAG:
+       case DOUBLE_FLOAT_WIDETAG:
+#ifdef LONG_FLOAT_WIDETAG
+       case LONG_FLOAT_WIDETAG:
 #endif
-       case type_SimpleString:
-       case type_SimpleBitVector:
-       case type_SimpleArrayUnsignedByte2:
-       case type_SimpleArrayUnsignedByte4:
-       case type_SimpleArrayUnsignedByte8:
-       case type_SimpleArrayUnsignedByte16:
-       case type_SimpleArrayUnsignedByte32:
-#ifdef type_SimpleArraySignedByte8
-       case type_SimpleArraySignedByte8:
+       case SIMPLE_BASE_STRING_WIDETAG:
+       case SIMPLE_BIT_VECTOR_WIDETAG:
+       case SIMPLE_ARRAY_NIL_WIDETAG:
+       case SIMPLE_ARRAY_UNSIGNED_BYTE_2_WIDETAG:
+       case SIMPLE_ARRAY_UNSIGNED_BYTE_4_WIDETAG:
+       case SIMPLE_ARRAY_UNSIGNED_BYTE_7_WIDETAG:
+       case SIMPLE_ARRAY_UNSIGNED_BYTE_8_WIDETAG:
+       case SIMPLE_ARRAY_UNSIGNED_BYTE_15_WIDETAG:
+       case SIMPLE_ARRAY_UNSIGNED_BYTE_16_WIDETAG:
+       case SIMPLE_ARRAY_UNSIGNED_BYTE_29_WIDETAG:
+       case SIMPLE_ARRAY_UNSIGNED_BYTE_31_WIDETAG:
+       case SIMPLE_ARRAY_UNSIGNED_BYTE_32_WIDETAG:
+#ifdef SIMPLE_ARRAY_SIGNED_BYTE_8_WIDETAG
+       case SIMPLE_ARRAY_SIGNED_BYTE_8_WIDETAG:
 #endif
-#ifdef type_SimpleArraySignedByte16
-       case type_SimpleArraySignedByte16:
+#ifdef SIMPLE_ARRAY_SIGNED_BYTE_16_WIDETAG
+       case SIMPLE_ARRAY_SIGNED_BYTE_16_WIDETAG:
 #endif
-#ifdef type_SimpleArraySignedByte30
-       case type_SimpleArraySignedByte30:
+#ifdef SIMPLE_ARRAY_SIGNED_BYTE_30_WIDETAG
+       case SIMPLE_ARRAY_SIGNED_BYTE_30_WIDETAG:
 #endif
-#ifdef type_SimpleArraySignedByte32
-       case type_SimpleArraySignedByte32:
+#ifdef SIMPLE_ARRAY_SIGNED_BYTE_32_WIDETAG
+       case SIMPLE_ARRAY_SIGNED_BYTE_32_WIDETAG:
 #endif
-       case type_SimpleArraySingleFloat:
-       case type_SimpleArrayDoubleFloat:
-#ifdef type_SimpleArrayLongFloat
-       case type_SimpleArrayLongFloat:
+       case SIMPLE_ARRAY_SINGLE_FLOAT_WIDETAG:
+       case SIMPLE_ARRAY_DOUBLE_FLOAT_WIDETAG:
+#ifdef SIMPLE_ARRAY_LONG_FLOAT_WIDETAG
+       case SIMPLE_ARRAY_LONG_FLOAT_WIDETAG:
 #endif
-#ifdef type_SimpleArrayComplexSingleFloat
-       case type_SimpleArrayComplexSingleFloat:
+#ifdef SIMPLE_ARRAY_COMPLEX_SINGLE_FLOAT_WIDETAG
+       case SIMPLE_ARRAY_COMPLEX_SINGLE_FLOAT_WIDETAG:
 #endif
-#ifdef type_SimpleArrayComplexDoubleFloat
-       case type_SimpleArrayComplexDoubleFloat:
+#ifdef SIMPLE_ARRAY_COMPLEX_DOUBLE_FLOAT_WIDETAG
+       case SIMPLE_ARRAY_COMPLEX_DOUBLE_FLOAT_WIDETAG:
 #endif
-#ifdef type_SimpleArrayComplexLongFloat
-       case type_SimpleArrayComplexLongFloat:
+#ifdef SIMPLE_ARRAY_COMPLEX_LONG_FLOAT_WIDETAG
+       case SIMPLE_ARRAY_COMPLEX_LONG_FLOAT_WIDETAG:
 #endif
-       case type_Sap:
-       case type_WeakPointer:
+       case SAP_WIDETAG:
+       case WEAK_POINTER_WIDETAG:
            break;
 
        default:
@@ -4152,12 +2388,13 @@ possibly_valid_dynamic_space_pointer(lispobj *pointer)
     return 1;
 }
 
-/* Adjust large bignum and vector objects. This will adjust the allocated
- * region if the size has shrunk, and move unboxed objects into unboxed
- * pages. The pages are not promoted here, and the promoted region is not
- * added to the new_regions; this is really only designed to be called from
- * preserve_pointer(). Shouldn't fail if this is missed, just may delay the
- * moving of objects to unboxed pages, and the freeing of pages. */
+/* Adjust large bignum and vector objects. This will adjust the
+ * allocated region if the size has shrunk, and move unboxed objects
+ * into unboxed pages. The pages are not promoted here, and the
+ * promoted region is not added to the new_regions; this is really
+ * only designed to be called from preserve_pointer(). Shouldn't fail
+ * if this is missed, just may delay the moving of objects to unboxed
+ * pages, and the freeing of pages. */
 static void
 maybe_adjust_large_object(lispobj *where)
 {
@@ -4172,43 +2409,48 @@ maybe_adjust_large_object(lispobj *where)
     int boxed;
 
     /* Check whether it's a vector or bignum object. */
-    switch (TypeOf(where[0])) {
-    case type_SimpleVector:
+    switch (widetag_of(where[0])) {
+    case SIMPLE_VECTOR_WIDETAG:
        boxed = BOXED_PAGE;
        break;
-    case type_Bignum:
-    case type_SimpleString:
-    case type_SimpleBitVector:
-    case type_SimpleArrayUnsignedByte2:
-    case type_SimpleArrayUnsignedByte4:
-    case type_SimpleArrayUnsignedByte8:
-    case type_SimpleArrayUnsignedByte16:
-    case type_SimpleArrayUnsignedByte32:
-#ifdef type_SimpleArraySignedByte8
-    case type_SimpleArraySignedByte8:
+    case BIGNUM_WIDETAG:
+    case SIMPLE_BASE_STRING_WIDETAG:
+    case SIMPLE_BIT_VECTOR_WIDETAG:
+    case SIMPLE_ARRAY_NIL_WIDETAG:
+    case SIMPLE_ARRAY_UNSIGNED_BYTE_2_WIDETAG:
+    case SIMPLE_ARRAY_UNSIGNED_BYTE_4_WIDETAG:
+    case SIMPLE_ARRAY_UNSIGNED_BYTE_7_WIDETAG:
+    case SIMPLE_ARRAY_UNSIGNED_BYTE_8_WIDETAG:
+    case SIMPLE_ARRAY_UNSIGNED_BYTE_15_WIDETAG:
+    case SIMPLE_ARRAY_UNSIGNED_BYTE_16_WIDETAG:
+    case SIMPLE_ARRAY_UNSIGNED_BYTE_29_WIDETAG:
+    case SIMPLE_ARRAY_UNSIGNED_BYTE_31_WIDETAG:
+    case SIMPLE_ARRAY_UNSIGNED_BYTE_32_WIDETAG:
+#ifdef SIMPLE_ARRAY_SIGNED_BYTE_8_WIDETAG
+    case SIMPLE_ARRAY_SIGNED_BYTE_8_WIDETAG:
 #endif
-#ifdef type_SimpleArraySignedByte16
-    case type_SimpleArraySignedByte16:
+#ifdef SIMPLE_ARRAY_SIGNED_BYTE_16_WIDETAG
+    case SIMPLE_ARRAY_SIGNED_BYTE_16_WIDETAG:
 #endif
-#ifdef type_SimpleArraySignedByte30
-    case type_SimpleArraySignedByte30:
+#ifdef SIMPLE_ARRAY_SIGNED_BYTE_30_WIDETAG
+    case SIMPLE_ARRAY_SIGNED_BYTE_30_WIDETAG:
 #endif
-#ifdef type_SimpleArraySignedByte32
-    case type_SimpleArraySignedByte32:
+#ifdef SIMPLE_ARRAY_SIGNED_BYTE_32_WIDETAG
+    case SIMPLE_ARRAY_SIGNED_BYTE_32_WIDETAG:
 #endif
-    case type_SimpleArraySingleFloat:
-    case type_SimpleArrayDoubleFloat:
-#ifdef type_SimpleArrayLongFloat
-    case type_SimpleArrayLongFloat:
+    case SIMPLE_ARRAY_SINGLE_FLOAT_WIDETAG:
+    case SIMPLE_ARRAY_DOUBLE_FLOAT_WIDETAG:
+#ifdef SIMPLE_ARRAY_LONG_FLOAT_WIDETAG
+    case SIMPLE_ARRAY_LONG_FLOAT_WIDETAG:
 #endif
-#ifdef type_SimpleArrayComplexSingleFloat
-    case type_SimpleArrayComplexSingleFloat:
+#ifdef SIMPLE_ARRAY_COMPLEX_SINGLE_FLOAT_WIDETAG
+    case SIMPLE_ARRAY_COMPLEX_SINGLE_FLOAT_WIDETAG:
 #endif
-#ifdef type_SimpleArrayComplexDoubleFloat
-    case type_SimpleArrayComplexDoubleFloat:
+#ifdef SIMPLE_ARRAY_COMPLEX_DOUBLE_FLOAT_WIDETAG
+    case SIMPLE_ARRAY_COMPLEX_DOUBLE_FLOAT_WIDETAG:
 #endif
-#ifdef type_SimpleArrayComplexLongFloat
-    case type_SimpleArrayComplexLongFloat:
+#ifdef SIMPLE_ARRAY_COMPLEX_LONG_FLOAT_WIDETAG
+    case SIMPLE_ARRAY_COMPLEX_LONG_FLOAT_WIDETAG:
 #endif
        boxed = UNBOXED_PAGE;
        break;
@@ -4217,7 +2459,7 @@ maybe_adjust_large_object(lispobj *where)
     }
 
     /* Find its current size. */
-    nwords = (sizetab[TypeOf(where[0])])(where);
+    nwords = (sizetab[widetag_of(where[0])])(where);
 
     first_page = find_page_index((void *)where);
     gc_assert(first_page >= 0);
@@ -4288,8 +2530,11 @@ maybe_adjust_large_object(lispobj *where)
        next_page++;
     }
 
-    if ((bytes_freed > 0) && gencgc_verbose)
-       FSHOW((stderr, "/adjust_large_object freed %d\n", bytes_freed));
+    if ((bytes_freed > 0) && gencgc_verbose) {
+       FSHOW((stderr,
+              "/maybe_adjust_large_object() freed %d\n",
+              bytes_freed));
+    }
 
     generations[from_space].bytes_allocated -= bytes_freed;
     bytes_allocated -= bytes_freed;
@@ -4302,16 +2547,16 @@ maybe_adjust_large_object(lispobj *where)
  *
  * This involves locating the page it points to, then backing up to
  * the first page that has its first object start at offset 0, and
- * then marking all pages dont_move from the first until a page that ends
- * by being full, or having free gen.
+ * then marking all pages dont_move from the first until a page that
+ * ends by being full, or having free gen.
  *
  * This ensures that objects spanning pages are not broken.
  *
  * It is assumed that all the page static flags have been cleared at
  * the start of a GC.
  *
- * It is also assumed that the current gc_alloc region has been flushed and
- * the tables updated. */
+ * It is also assumed that the current gc_alloc() region has been
+ * flushed and the tables updated. */
 static void
 preserve_pointer(void *addr)
 {
@@ -4328,7 +2573,7 @@ preserve_pointer(void *addr)
        /* Skip if already marked dont_move. */
        || (page_table[addr_page_index].dont_move != 0))
        return;
-
+    gc_assert(!(page_table[addr_page_index].allocated & OPEN_REGION_PAGE));
     /* (Now that we know that addr_page_index is in range, it's
      * safe to index into page_table[] with it.) */
     region_allocation = page_table[addr_page_index].allocated;
@@ -4345,15 +2590,22 @@ preserve_pointer(void *addr)
      * (or, as a special case which also requires dont_move, a return
      * address referring to something in a CodeObject). This is
      * expensive but important, since it vastly reduces the
-     * probability that random garbage will be bogusly interpreter as
+     * probability that random garbage will be bogusly interpreted as
      * a pointer which prevents a page from moving. */
-    if (enable_pointer_filter && !possibly_valid_dynamic_space_pointer(addr))
+    if (!(possibly_valid_dynamic_space_pointer(addr)))
        return;
+    first_page = addr_page_index;
 
     /* Work backwards to find a page with a first_object_offset of 0.
      * The pages should be contiguous with all bytes used in the same
      * gen. Assumes the first_object_offset is negative or zero. */
-    first_page = addr_page_index;
+
+    /* this is probably needlessly conservative.  The first object in
+     * the page may not even be the one we were passed a pointer to:
+     * if this is the case, we will write-protect all the previous
+     * object's pages too.
+     */
+
     while (page_table[first_page].first_object_offset != 0) {
        --first_page;
        /* Do some checks. */
@@ -4362,13 +2614,14 @@ preserve_pointer(void *addr)
        gc_assert(page_table[first_page].allocated == region_allocation);
     }
 
-    /* Adjust any large objects before promotion as they won't be copied
-     * after promotion. */
+    /* Adjust any large objects before promotion as they won't be
+     * copied after promotion. */
     if (page_table[first_page].large_object) {
        maybe_adjust_large_object(page_address(first_page));
-       /* If a large object has shrunk then addr may now point to a free
-        * area in which case it's ignored here. Note it gets through the
-        * valid pointer test above because the tail looks like conses. */
+       /* If a large object has shrunk then addr may now point to a
+        * free area in which case it's ignored here. Note it gets
+        * through the valid pointer test above because the tail looks
+        * like conses. */
        if ((page_table[addr_page_index].allocated == FREE_PAGE)
            || (page_table[addr_page_index].bytes_used == 0)
            /* Check the offset within the page. */
@@ -4391,17 +2644,18 @@ preserve_pointer(void *addr)
        /* Mark the page static. */
        page_table[i].dont_move = 1;
 
-       /* Move the page to the new_space. XX I'd rather not do this but
-        * the GC logic is not quite able to copy with the static pages
-        * remaining in the from space. This also requires the generation
-        * bytes_allocated counters be updated. */
+       /* Move the page to the new_space. XX I'd rather not do this
+        * but the GC logic is not quite able to copy with the static
+        * pages remaining in the from space. This also requires the
+        * generation bytes_allocated counters be updated. */
        page_table[i].gen = new_space;
        generations[new_space].bytes_allocated += page_table[i].bytes_used;
        generations[from_space].bytes_allocated -= page_table[i].bytes_used;
 
-       /* It is essential that the pages are not write protected as they
-        * may have pointers into the old-space which need scavenging. They
-        * shouldn't be write protected at this stage. */
+       /* It is essential that the pages are not write protected as
+        * they may have pointers into the old-space which need
+        * scavenging. They shouldn't be write protected at this
+        * stage. */
        gc_assert(!page_table[i].write_protected);
 
        /* Check whether this is the last page in this contiguous block.. */
@@ -4416,91 +2670,21 @@ preserve_pointer(void *addr)
 
     /* Check that the page is now static. */
     gc_assert(page_table[addr_page_index].dont_move != 0);
-
-    return;
-}
-
-#ifdef CONTROL_STACKS
-/* Scavenge the thread stack conservative roots. */
-static void
-scavenge_thread_stacks(void)
-{
-    lispobj thread_stacks = SymbolValue(CONTROL_STACKS);
-    int type = TypeOf(thread_stacks);
-
-    if (LowtagOf(thread_stacks) == type_OtherPointer) {
-       struct vector *vector = (struct vector *) PTR(thread_stacks);
-       int length, i;
-       if (TypeOf(vector->header) != type_SimpleVector)
-           return;
-       length = fixnum_value(vector->length);
-       for (i = 0; i < length; i++) {
-           lispobj stack_obj = vector->data[i];
-           if (LowtagOf(stack_obj) == type_OtherPointer) {
-               struct vector *stack = (struct vector *) PTR(stack_obj);
-               int vector_length;
-               if (TypeOf(stack->header) !=
-                   type_SimpleArrayUnsignedByte32) {
-                   return;
-               }
-               vector_length = fixnum_value(stack->length);
-               if ((gencgc_verbose > 1) && (vector_length <= 0))
-                   FSHOW((stderr,
-                          "/weird? control stack vector length %d\n",
-                          vector_length));
-               if (vector_length > 0) {
-                   lispobj *stack_pointer = (lispobj*)stack->data[0];
-                   if ((stack_pointer < (lispobj *)CONTROL_STACK_START) ||
-                       (stack_pointer > (lispobj *)CONTROL_STACK_END))
-                       lose("invalid stack pointer %x",
-                            (unsigned)stack_pointer);
-                   if ((stack_pointer > (lispobj *)CONTROL_STACK_START) &&
-                       (stack_pointer < (lispobj *)CONTROL_STACK_END)) {
-                       /* FIXME: Ick!
-                        *   (1) hardwired word length = 4; and as usual,
-                        *       when fixing this, check for other places
-                        *       with the same problem
-                        *   (2) calling it 'length' suggests bytes;
-                        *       perhaps 'size' instead? */
-                       unsigned int length = ((unsigned)CONTROL_STACK_END -
-                                              (unsigned)stack_pointer) / 4;
-                       int j;
-                       if (length >= vector_length) {
-                           lose("invalid stack size %d >= vector length %d",
-                                length,
-                                vector_length);
-                       }
-                       if (gencgc_verbose > 1) {
-                           FSHOW((stderr,
-                                  "scavenging %d words of control stack %d of length %d words.\n",
-                                   length, i, vector_length));
-                       }
-                       for (j = 0; j < length; j++) {
-                           preserve_pointer((void *)stack->data[1+j]);
-                       }
-                   }
-               }
-           }
-       }
-    }
 }
-#endif
-
 \f
 /* If the given page is not write-protected, then scan it for pointers
  * to younger generations or the top temp. generation, if no
  * suspicious pointers are found then the page is write-protected.
  *
- * Care is taken to check for pointers to the current gc_alloc region
- * if it is a younger generation or the temp. generation. This frees
- * the caller from doing a gc_alloc_update_page_tables. Actually the
- * gc_alloc_generation does not need to be checked as this is only
- * called from scavenge_generation when the gc_alloc generation is
+ * Care is taken to check for pointers to the current gc_alloc()
+ * region if it is a younger generation or the temp. generation. This
+ * frees the caller from doing a gc_alloc_update_page_tables(). Actually
+ * the gc_alloc_generation does not need to be checked as this is only
+ * called from scavenge_generation() when the gc_alloc generation is
  * younger, so it just checks if there is a pointer to the current
  * region.
  *
- * We return 1 if the page was write-protected, else 0.
- */
+ * We return 1 if the page was write-protected, else 0. */
 static int
 update_page_write_prot(int page)
 {
@@ -4514,9 +2698,10 @@ update_page_write_prot(int page)
     gc_assert(page_table[page].allocated != FREE_PAGE);
     gc_assert(page_table[page].bytes_used != 0);
 
-    /* Skip if it's already write-protected or an unboxed page. */
+    /* Skip if it's already write-protected, pinned, or unboxed */
     if (page_table[page].write_protected
-       || (page_table[page].allocated == UNBOXED_PAGE))
+       || page_table[page].dont_move
+       || (page_table[page].allocated & UNBOXED_PAGE))
        return (0);
 
     /* Scan the page for pointers to younger generations or the
@@ -4534,7 +2719,7 @@ update_page_write_prot(int page)
                 && ((page_table[index].gen < gen)
                     || (page_table[index].gen == NUM_GENERATIONS)))
 
-               /* Or does it point within a current gc_alloc region? */
+               /* Or does it point within a current gc_alloc() region? */
                || ((boxed_region.start_addr <= ptr)
                    && (ptr <= boxed_region.free_pointer))
                || ((unboxed_region.start_addr <= ptr)
@@ -4604,7 +2789,7 @@ scavenge_generation(int generation)
 #endif
 
     for (i = 0; i < last_free_page; i++) {
-       if ((page_table[i].allocated == BOXED_PAGE)
+       if ((page_table[i].allocated & BOXED_PAGE)
            && (page_table[i].bytes_used != 0)
            && (page_table[i].gen == generation)) {
            int last_page;
@@ -4618,12 +2803,12 @@ scavenge_generation(int generation)
            /* Now work forward until the end of this contiguous area
             * is found. A small area is preferred as there is a
             * better chance of its pages being write-protected. */
-           for (last_page = i; ;last_page++)
+           for (last_page = i; ; last_page++)
                /* Check whether this is the last page in this contiguous
                 * block. */
                if ((page_table[last_page].bytes_used < 4096)
                    /* Or it is 4096 and is the last in the block */
-                   || (page_table[last_page+1].allocated != BOXED_PAGE)
+                   || (!(page_table[last_page+1].allocated & BOXED_PAGE))
                    || (page_table[last_page+1].bytes_used == 0)
                    || (page_table[last_page+1].gen != generation)
                    || (page_table[last_page+1].first_object_offset == 0))
@@ -4673,14 +2858,13 @@ scavenge_generation(int generation)
            && (page_table[i].bytes_used != 0)
            && (page_table[i].gen == generation)
            && (page_table[i].write_protected_cleared != 0)) {
-           FSHOW((stderr, "/scavenge_generation %d\n", generation));
+           FSHOW((stderr, "/scavenge_generation() %d\n", generation));
            FSHOW((stderr,
                   "/page bytes_used=%d first_object_offset=%d dont_move=%d\n",
                    page_table[i].bytes_used,
                    page_table[i].first_object_offset,
                    page_table[i].dont_move));
-           lose("write-protected page %d written to in scavenge_generation",
-                i);
+           lose("write to protected page %d in scavenge_generation()", i);
        }
     }
 #endif
@@ -4693,7 +2877,7 @@ scavenge_generation(int generation)
  * newspace generation.
  *
  * To help improve the efficiency, areas written are recorded by
- * gc_alloc and only these scavenged. Sometimes a little more will be
+ * gc_alloc() and only these scavenged. Sometimes a little more will be
  * scavenged, but this causes no harm. An easy check is done that the
  * scavenged bytes equals the number allocated in the previous
  * scavenge.
@@ -4704,7 +2888,7 @@ scavenge_generation(int generation)
  *
  * Write-protected pages could potentially be written by alloc however
  * to avoid having to handle re-scavenging of write-protected pages
- * gc_alloc does not write to write-protected pages.
+ * gc_alloc() does not write to write-protected pages.
  *
  * New areas of objects allocated are recorded alternatively in the two
  * new_areas arrays below. */
@@ -4722,8 +2906,8 @@ scavenge_newspace_generation_one_scan(int generation)
     FSHOW((stderr,
           "/starting one full scan of newspace generation %d\n",
           generation));
-
     for (i = 0; i < last_free_page; i++) {
+       /* note that this skips over open regions when it encounters them */
        if ((page_table[i].allocated == BOXED_PAGE)
            && (page_table[i].bytes_used != 0)
            && (page_table[i].gen == generation)
@@ -4746,7 +2930,7 @@ scavenge_newspace_generation_one_scan(int generation)
                 * contiguous block */
                if ((page_table[last_page].bytes_used < 4096)
                    /* Or it is 4096 and is the last in the block */
-                   || (page_table[last_page+1].allocated != BOXED_PAGE)
+                   || (!(page_table[last_page+1].allocated & BOXED_PAGE))
                    || (page_table[last_page+1].bytes_used == 0)
                    || (page_table[last_page+1].gen != generation)
                    || (page_table[last_page+1].first_object_offset == 0))
@@ -4802,7 +2986,7 @@ scavenge_newspace_generation(int generation)
 {
     int i;
 
-    /* the new_areas array currently being written to by gc_alloc */
+    /* the new_areas array currently being written to by gc_alloc() */
     struct new_area (*current_new_areas)[] = &new_areas_1;
     int current_new_areas_index;
 
@@ -4811,10 +2995,9 @@ scavenge_newspace_generation(int generation)
     int previous_new_areas_index;
 
     /* Flush the current regions updating the tables. */
-    gc_alloc_update_page_tables(0, &boxed_region);
-    gc_alloc_update_page_tables(1, &unboxed_region);
+    gc_alloc_update_all_page_tables();
 
-    /* Turn on the recording of new areas by gc_alloc. */
+    /* Turn on the recording of new areas by gc_alloc(). */
     new_areas = current_new_areas;
     new_areas_index = 0;
 
@@ -4829,8 +3012,7 @@ scavenge_newspace_generation(int generation)
     record_new_objects = 2;
 
     /* Flush the current regions updating the tables. */
-    gc_alloc_update_page_tables(0, &boxed_region);
-    gc_alloc_update_page_tables(1, &unboxed_region);
+    gc_alloc_update_all_page_tables();
 
     /* Grab new_areas_index. */
     current_new_areas_index = new_areas_index;
@@ -4854,7 +3036,7 @@ scavenge_newspace_generation(int generation)
        else
            current_new_areas = &new_areas_1;
 
-       /* Set up for gc_alloc. */
+       /* Set up for gc_alloc(). */
        new_areas = current_new_areas;
        new_areas_index = 0;
 
@@ -4877,8 +3059,7 @@ scavenge_newspace_generation(int generation)
            record_new_objects = 2;
 
            /* Flush the current regions updating the tables. */
-           gc_alloc_update_page_tables(0, &boxed_region);
-           gc_alloc_update_page_tables(1, &unboxed_region);
+           gc_alloc_update_all_page_tables();
 
        } else {
 
@@ -4890,13 +3071,11 @@ scavenge_newspace_generation(int generation)
                int offset = (*previous_new_areas)[i].offset;
                int size = (*previous_new_areas)[i].size / 4;
                gc_assert((*previous_new_areas)[i].size % 4 == 0);
-
                scavenge(page_address(page)+offset, size);
            }
 
            /* Flush the current regions updating the tables. */
-           gc_alloc_update_page_tables(0, &boxed_region);
-           gc_alloc_update_page_tables(1, &unboxed_region);
+           gc_alloc_update_all_page_tables();
        }
 
        current_new_areas_index = new_areas_index;
@@ -4906,7 +3085,7 @@ scavenge_newspace_generation(int generation)
                 current_new_areas_index));*/
     }
 
-    /* Turn off recording of areas allocated by gc_alloc. */
+    /* Turn off recording of areas allocated by gc_alloc(). */
     record_new_objects = 0;
 
 #if SC_NS_GEN_CK
@@ -5083,20 +3262,20 @@ verify_space(lispobj *start, size_t words)
     int is_in_dynamic_space = (find_page_index((void*)start) != -1);
     int is_in_readonly_space =
        (READ_ONLY_SPACE_START <= (unsigned)start &&
-        (unsigned)start < SymbolValue(READ_ONLY_SPACE_FREE_POINTER));
+        (unsigned)start < SymbolValue(READ_ONLY_SPACE_FREE_POINTER,0));
 
     while (words > 0) {
        size_t count = 1;
        lispobj thing = *(lispobj*)start;
 
-       if (Pointerp(thing)) {
+       if (is_lisp_pointer(thing)) {
            int page_index = find_page_index((void*)thing);
            int to_readonly_space =
                (READ_ONLY_SPACE_START <= thing &&
-                thing < SymbolValue(READ_ONLY_SPACE_FREE_POINTER));
+                thing < SymbolValue(READ_ONLY_SPACE_FREE_POINTER,0));
            int to_static_space =
                (STATIC_SPACE_START <= thing &&
-                thing < SymbolValue(STATIC_SPACE_FREE_POINTER));
+                thing < SymbolValue(STATIC_SPACE_FREE_POINTER,0));
 
            /* Does it point to the dynamic space? */
            if (page_index != -1) {
@@ -5106,7 +3285,7 @@ verify_space(lispobj *start, size_t words)
                    && (page_table[page_index].bytes_used == 0))
                    lose ("Ptr %x @ %x sees free page.", thing, start);
                /* Check that it doesn't point to a forwarding pointer! */
-               if (*((lispobj *)PTR(thing)) == 0x01) {
+               if (*((lispobj *)native_pointer(thing)) == 0x01) {
                    lose("Ptr %x @ %x sees forwarding ptr.", thing, start);
                }
                /* Check that its not in the RO space as it would then be a
@@ -5118,9 +3297,17 @@ verify_space(lispobj *start, size_t words)
                /* Does it point to a plausible object? This check slows
                 * it down a lot (so it's commented out).
                 *
-                * FIXME: Add a variable to enable this dynamically. */
-               /* if (!possibly_valid_dynamic_space_pointer((lispobj *)thing)) {
-                *     lose("ptr %x to invalid object %x", thing, start); */
+                * "a lot" is serious: it ate 50 minutes cpu time on
+                * my duron 950 before I came back from lunch and
+                * killed it.
+                *
+                *   FIXME: Add a variable to enable this
+                * dynamically. */
+               /*
+               if (!possibly_valid_dynamic_space_pointer((lispobj *)thing)) {
+                   lose("ptr %x to invalid object %x", thing, start); 
+               }
+               */
            } else {
                /* Verify that it points to another valid space. */
                if (!to_readonly_space && !to_static_space
@@ -5132,37 +3319,36 @@ verify_space(lispobj *start, size_t words)
            if (thing & 0x3) { /* Skip fixnums. FIXME: There should be an
                                * is_fixnum for this. */
 
-               switch(TypeOf(*start)) {
+               switch(widetag_of(*start)) {
 
                    /* boxed objects */
-               case type_SimpleVector:
-               case type_Ratio:
-               case type_Complex:
-               case type_SimpleArray:
-               case type_ComplexString:
-               case type_ComplexBitVector:
-               case type_ComplexVector:
-               case type_ComplexArray:
-               case type_ClosureHeader:
-               case type_FuncallableInstanceHeader:
-               case type_ByteCodeFunction:
-               case type_ByteCodeClosure:
-               case type_ValueCellHeader:
-               case type_SymbolHeader:
-               case type_BaseChar:
-               case type_UnboundMarker:
-               case type_InstanceHeader:
-               case type_Fdefn:
+               case SIMPLE_VECTOR_WIDETAG:
+               case RATIO_WIDETAG:
+               case COMPLEX_WIDETAG:
+               case SIMPLE_ARRAY_WIDETAG:
+               case COMPLEX_BASE_STRING_WIDETAG:
+               case COMPLEX_VECTOR_NIL_WIDETAG:
+               case COMPLEX_BIT_VECTOR_WIDETAG:
+               case COMPLEX_VECTOR_WIDETAG:
+               case COMPLEX_ARRAY_WIDETAG:
+               case CLOSURE_HEADER_WIDETAG:
+               case FUNCALLABLE_INSTANCE_HEADER_WIDETAG:
+               case VALUE_CELL_HEADER_WIDETAG:
+               case SYMBOL_HEADER_WIDETAG:
+               case BASE_CHAR_WIDETAG:
+               case UNBOUND_MARKER_WIDETAG:
+               case INSTANCE_HEADER_WIDETAG:
+               case FDEFN_WIDETAG:
                    count = 1;
                    break;
 
-               case type_CodeHeader:
+               case CODE_HEADER_WIDETAG:
                    {
                        lispobj object = *start;
                        struct code *code;
                        int nheader_words, ncode_words, nwords;
                        lispobj fheaderl;
-                       struct function *fheaderp;
+                       struct simple_fun *fheaderp;
 
                        code = (struct code *) start;
 
@@ -5172,7 +3358,13 @@ verify_space(lispobj *start, size_t words)
                        if (is_in_dynamic_space
                            /* It's ok if it's byte compiled code. The trace
                             * table offset will be a fixnum if it's x86
-                            * compiled code - check. */
+                            * compiled code - check.
+                            *
+                            * FIXME: #^#@@! lack of abstraction here..
+                            * This line can probably go away now that
+                            * there's no byte compiler, but I've got
+                            * too much to worry about right now to try
+                            * to make sure. -- WHN 2001-10-06 */
                            && !(code->trace_table_offset & 0x3)
                            /* Only when enabled */
                            && verify_dynamic_code_check) {
@@ -5188,12 +3380,13 @@ verify_space(lispobj *start, size_t words)
                        /* Scavenge the boxed section of the code data block */
                        verify_space(start + 1, nheader_words - 1);
 
-                       /* Scavenge the boxed section of each function object in
-                        * the code data block. */
+                       /* Scavenge the boxed section of each function
+                        * object in the code data block. */
                        fheaderl = code->entry_points;
                        while (fheaderl != NIL) {
-                           fheaderp = (struct function *) PTR(fheaderl);
-                           gc_assert(TypeOf(fheaderp->header) == type_FunctionHeader);
+                           fheaderp =
+                               (struct simple_fun *) native_pointer(fheaderl);
+                           gc_assert(widetag_of(fheaderp->header) == SIMPLE_FUN_HEADER_WIDETAG);
                            verify_space(&fheaderp->name, 1);
                            verify_space(&fheaderp->arglist, 1);
                            verify_space(&fheaderp->type, 1);
@@ -5204,57 +3397,62 @@ verify_space(lispobj *start, size_t words)
                    }
        
                    /* unboxed objects */
-               case type_Bignum:
-               case type_SingleFloat:
-               case type_DoubleFloat:
-#ifdef type_ComplexLongFloat
-               case type_LongFloat:
+               case BIGNUM_WIDETAG:
+               case SINGLE_FLOAT_WIDETAG:
+               case DOUBLE_FLOAT_WIDETAG:
+#ifdef COMPLEX_LONG_FLOAT_WIDETAG
+               case LONG_FLOAT_WIDETAG:
 #endif
-#ifdef type_ComplexSingleFloat
-               case type_ComplexSingleFloat:
+#ifdef COMPLEX_SINGLE_FLOAT_WIDETAG
+               case COMPLEX_SINGLE_FLOAT_WIDETAG:
 #endif
-#ifdef type_ComplexDoubleFloat
-               case type_ComplexDoubleFloat:
+#ifdef COMPLEX_DOUBLE_FLOAT_WIDETAG
+               case COMPLEX_DOUBLE_FLOAT_WIDETAG:
 #endif
-#ifdef type_ComplexLongFloat
-               case type_ComplexLongFloat:
+#ifdef COMPLEX_LONG_FLOAT_WIDETAG
+               case COMPLEX_LONG_FLOAT_WIDETAG:
 #endif
-               case type_SimpleString:
-               case type_SimpleBitVector:
-               case type_SimpleArrayUnsignedByte2:
-               case type_SimpleArrayUnsignedByte4:
-               case type_SimpleArrayUnsignedByte8:
-               case type_SimpleArrayUnsignedByte16:
-               case type_SimpleArrayUnsignedByte32:
-#ifdef type_SimpleArraySignedByte8
-               case type_SimpleArraySignedByte8:
+               case SIMPLE_BASE_STRING_WIDETAG:
+               case SIMPLE_BIT_VECTOR_WIDETAG:
+               case SIMPLE_ARRAY_NIL_WIDETAG:
+               case SIMPLE_ARRAY_UNSIGNED_BYTE_2_WIDETAG:
+               case SIMPLE_ARRAY_UNSIGNED_BYTE_4_WIDETAG:
+               case SIMPLE_ARRAY_UNSIGNED_BYTE_7_WIDETAG:
+               case SIMPLE_ARRAY_UNSIGNED_BYTE_8_WIDETAG:
+               case SIMPLE_ARRAY_UNSIGNED_BYTE_15_WIDETAG:
+               case SIMPLE_ARRAY_UNSIGNED_BYTE_16_WIDETAG:
+               case SIMPLE_ARRAY_UNSIGNED_BYTE_29_WIDETAG:
+               case SIMPLE_ARRAY_UNSIGNED_BYTE_31_WIDETAG:
+               case SIMPLE_ARRAY_UNSIGNED_BYTE_32_WIDETAG:
+#ifdef SIMPLE_ARRAY_SIGNED_BYTE_8_WIDETAG
+               case SIMPLE_ARRAY_SIGNED_BYTE_8_WIDETAG:
 #endif
-#ifdef type_SimpleArraySignedByte16
-               case type_SimpleArraySignedByte16:
+#ifdef SIMPLE_ARRAY_SIGNED_BYTE_16_WIDETAG
+               case SIMPLE_ARRAY_SIGNED_BYTE_16_WIDETAG:
 #endif
-#ifdef type_SimpleArraySignedByte30
-               case type_SimpleArraySignedByte30:
+#ifdef SIMPLE_ARRAY_SIGNED_BYTE_30_WIDETAG
+               case SIMPLE_ARRAY_SIGNED_BYTE_30_WIDETAG:
 #endif
-#ifdef type_SimpleArraySignedByte32
-               case type_SimpleArraySignedByte32:
+#ifdef SIMPLE_ARRAY_SIGNED_BYTE_32_WIDETAG
+               case SIMPLE_ARRAY_SIGNED_BYTE_32_WIDETAG:
 #endif
-               case type_SimpleArraySingleFloat:
-               case type_SimpleArrayDoubleFloat:
-#ifdef type_SimpleArrayComplexLongFloat
-               case type_SimpleArrayLongFloat:
+               case SIMPLE_ARRAY_SINGLE_FLOAT_WIDETAG:
+               case SIMPLE_ARRAY_DOUBLE_FLOAT_WIDETAG:
+#ifdef SIMPLE_ARRAY_COMPLEX_LONG_FLOAT_WIDETAG
+               case SIMPLE_ARRAY_LONG_FLOAT_WIDETAG:
 #endif
-#ifdef type_SimpleArrayComplexSingleFloat
-               case type_SimpleArrayComplexSingleFloat:
+#ifdef SIMPLE_ARRAY_COMPLEX_SINGLE_FLOAT_WIDETAG
+               case SIMPLE_ARRAY_COMPLEX_SINGLE_FLOAT_WIDETAG:
 #endif
-#ifdef type_SimpleArrayComplexDoubleFloat
-               case type_SimpleArrayComplexDoubleFloat:
+#ifdef SIMPLE_ARRAY_COMPLEX_DOUBLE_FLOAT_WIDETAG
+               case SIMPLE_ARRAY_COMPLEX_DOUBLE_FLOAT_WIDETAG:
 #endif
-#ifdef type_SimpleArrayComplexLongFloat
-               case type_SimpleArrayComplexLongFloat:
+#ifdef SIMPLE_ARRAY_COMPLEX_LONG_FLOAT_WIDETAG
+               case SIMPLE_ARRAY_COMPLEX_LONG_FLOAT_WIDETAG:
 #endif
-               case type_Sap:
-               case type_WeakPointer:
-                   count = (sizetab[TypeOf(*start)])(start);
+               case SAP_WIDETAG:
+               case WEAK_POINTER_WIDETAG:
+                   count = (sizetab[widetag_of(*start)])(start);
                    break;
 
                default:
@@ -5277,18 +3475,20 @@ verify_gc(void)
      * to grep for all foo_size and rename the appropriate ones to
      * foo_count. */
     int read_only_space_size =
-       (lispobj*)SymbolValue(READ_ONLY_SPACE_FREE_POINTER)
+       (lispobj*)SymbolValue(READ_ONLY_SPACE_FREE_POINTER,0)
        - (lispobj*)READ_ONLY_SPACE_START;
     int static_space_size =
-       (lispobj*)SymbolValue(STATIC_SPACE_FREE_POINTER)
+       (lispobj*)SymbolValue(STATIC_SPACE_FREE_POINTER,0)
        - (lispobj*)STATIC_SPACE_START;
+    struct thread *th;
+    for_each_thread(th) {
     int binding_stack_size =
-       (lispobj*)SymbolValue(BINDING_STACK_POINTER)
-       - (lispobj*)BINDING_STACK_START;
-
+           (lispobj*)SymbolValue(BINDING_STACK_POINTER,th)
+           - (lispobj*)th->binding_stack_start;
+       verify_space(th->binding_stack_start, binding_stack_size);
+    }
     verify_space((lispobj*)READ_ONLY_SPACE_START, read_only_space_size);
     verify_space((lispobj*)STATIC_SPACE_START   , static_space_size);
-    verify_space((lispobj*)BINDING_STACK_START  , binding_stack_size);
 }
 
 static void
@@ -5329,7 +3529,7 @@ verify_generation(int  generation)
     }
 }
 
-/* Check the all the free space is zero filled. */
+/* Check that all the free space is zero filled. */
 static void
 verify_zero_fill(void)
 {
@@ -5368,13 +3568,9 @@ void
 gencgc_verify_zero_fill(void)
 {
     /* Flush the alloc regions updating the tables. */
-    boxed_region.free_pointer = current_region_free_pointer;
-    gc_alloc_update_page_tables(0, &boxed_region);
-    gc_alloc_update_page_tables(1, &unboxed_region);
+    gc_alloc_update_all_page_tables();
     SHOW("verifying zero fill");
     verify_zero_fill();
-    current_region_free_pointer = boxed_region.free_pointer;
-    current_region_end_addr = boxed_region.end_addr;
 }
 
 static void
@@ -5400,6 +3596,7 @@ write_protect_generation_pages(int generation)
     for (i = 0; i < last_free_page; i++)
        if ((page_table[i].allocated == BOXED_PAGE)
            && (page_table[i].bytes_used != 0)
+           && !page_table[i].dont_move
            && (page_table[i].gen == generation))  {
            void *page_start;
 
@@ -5429,8 +3626,8 @@ garbage_collect_generation(int generation, int raise)
 {
     unsigned long bytes_freed;
     unsigned long i;
-    unsigned long read_only_space_size, static_space_size;
-
+    unsigned long static_space_size;
+    struct thread *th;
     gc_assert(generation <= (NUM_GENERATIONS-1));
 
     /* The oldest generation can't be raised. */
@@ -5463,7 +3660,8 @@ garbage_collect_generation(int generation, int raise)
     /* Before any pointers are preserved, the dont_move flags on the
      * pages need to be cleared. */
     for (i = 0; i < last_free_page; i++)
-       page_table[i].dont_move = 0;
+       if(page_table[i].gen==from_space)
+           page_table[i].dont_move = 0;
 
     /* Un-write-protect the old-space pages. This is essential for the
      * promoted pages as they may contain pointers into the old-space
@@ -5472,45 +3670,91 @@ garbage_collect_generation(int generation, int raise)
      * be un-protected anyway before unmapping later. */
     unprotect_oldspace();
 
-    /* Scavenge the stack's conservative roots. */
-    {
+    /* Scavenge the stacks' conservative roots. */
+
+    /* there are potentially two stacks for each thread: the main
+     * stack, which may contain Lisp pointers, and the alternate stack.
+     * We don't ever run Lisp code on the altstack, but it may 
+     * host a sigcontext with lisp objects in it */
+
+    /* what we need to do: (1) find the stack pointer for the main
+     * stack; scavenge it (2) find the interrupt context on the
+     * alternate stack that might contain lisp values, and scavenge
+     * that */
+
+    /* we assume that none of the preceding applies to the thread that
+     * initiates GC.  If you ever call GC from inside an altstack
+     * handler, you will lose. */
+    for_each_thread(th) {
        void **ptr;
-       for (ptr = (void **)CONTROL_STACK_END - 1;
-            ptr > (void **)&raise;
-            ptr--) {
+       void **esp=(void **)-1;
+       int i,free;
+#ifdef LISP_FEATURE_SB_THREAD
+       if(th==arch_os_get_current_thread()) {
+           esp = (void **) &raise;
+       } else {
+           void **esp1;
+           free=fixnum_value(SymbolValue(FREE_INTERRUPT_CONTEXT_INDEX,th));
+           for(i=free-1;i>=0;i--) {
+               os_context_t *c=th->interrupt_contexts[i];
+               esp1 = (void **) *os_context_register_addr(c,reg_ESP);
+               if(esp1>=th->control_stack_start&& esp1<th->control_stack_end){
+                   if(esp1<esp) esp=esp1;
+                   for(ptr = (void **)(c+1); ptr>=(void **)c; ptr--) {
+                       preserve_pointer(*ptr);
+                   }
+               }
+           }
+       }
+#else
+       esp = (void **) &raise;
+#endif
+       for (ptr = (void **)th->control_stack_end; ptr > esp;  ptr--) {
            preserve_pointer(*ptr);
        }
     }
-#ifdef CONTROL_STACKS
-    scavenge_thread_stacks();
-#endif
 
+#if QSHOW
     if (gencgc_verbose > 1) {
        int num_dont_move_pages = count_dont_move_pages();
-       FSHOW((stderr,
-              "/non-movable pages due to conservative pointers = %d (%d bytes)\n",
-              num_dont_move_pages,
-              /* FIXME: 4096 should be symbolic constant here and
-               * prob'ly elsewhere too. */
-              num_dont_move_pages * 4096));
+       fprintf(stderr,
+               "/non-movable pages due to conservative pointers = %d (%d bytes)\n",
+               num_dont_move_pages,
+               /* FIXME: 4096 should be symbolic constant here and
+                * prob'ly elsewhere too. */
+               num_dont_move_pages * 4096);
     }
+#endif
 
     /* Scavenge all the rest of the roots. */
 
     /* Scavenge the Lisp functions of the interrupt handlers, taking
-     * care to avoid SIG_DFL, SIG_IGN. */
+     * care to avoid SIG_DFL and SIG_IGN. */
+    for_each_thread(th) {
+       struct interrupt_data *data=th->interrupt_data;
     for (i = 0; i < NSIG; i++) {
-       union interrupt_handler handler = interrupt_handlers[i];
+           union interrupt_handler handler = data->interrupt_handlers[i];
        if (!ARE_SAME_HANDLER(handler.c, SIG_IGN) &&
            !ARE_SAME_HANDLER(handler.c, SIG_DFL)) {
-           scavenge((lispobj *)(interrupt_handlers + i), 1);
+               scavenge((lispobj *)(data->interrupt_handlers + i), 1);
+           }
+       }
+    }
+    /* Scavenge the binding stacks. */
+ {
+     struct thread *th;
+     for_each_thread(th) {
+        long len= (lispobj *)SymbolValue(BINDING_STACK_POINTER,th) -
+            th->binding_stack_start;
+        scavenge((lispobj *) th->binding_stack_start,len);
+#ifdef LISP_FEATURE_SB_THREAD
+        /* do the tls as well */
+        len=fixnum_value(SymbolValue(FREE_TLS_INDEX,0)) -
+            (sizeof (struct thread))/(sizeof (lispobj));
+         scavenge((lispobj *) (th+1),len);
+#endif
        }
     }
-
-    /* Scavenge the binding stack. */
-    scavenge( (lispobj *) BINDING_STACK_START,
-            (lispobj *)SymbolValue(BINDING_STACK_POINTER) -
-            (lispobj *)BINDING_STACK_START);
 
     /* The original CMU CL code had scavenge-read-only-space code
      * controlled by the Lisp-level variable
@@ -5521,7 +3765,7 @@ garbage_collect_generation(int generation, int raise)
      * please submit a patch. */
 #if 0
     if (SymbolValue(SCAVENGE_READ_ONLY_SPACE) != NIL) {
-       read_only_space_size =
+       unsigned long read_only_space_size =
            (lispobj*)SymbolValue(READ_ONLY_SPACE_FREE_POINTER) -
            (lispobj*)READ_ONLY_SPACE_START;
        FSHOW((stderr,
@@ -5533,20 +3777,23 @@ garbage_collect_generation(int generation, int raise)
 
     /* Scavenge static space. */
     static_space_size =
-       (lispobj *)SymbolValue(STATIC_SPACE_FREE_POINTER) -
+       (lispobj *)SymbolValue(STATIC_SPACE_FREE_POINTER,0) -
        (lispobj *)STATIC_SPACE_START;
-    if (gencgc_verbose > 1)
+    if (gencgc_verbose > 1) {
        FSHOW((stderr,
               "/scavenge static space: %d bytes\n",
               static_space_size * sizeof(lispobj)));
+    }
     scavenge( (lispobj *) STATIC_SPACE_START, static_space_size);
 
     /* All generations but the generation being GCed need to be
      * scavenged. The new_space generation needs special handling as
      * objects may be moved in - it is handled separately below. */
-    for (i = 0; i < NUM_GENERATIONS; i++)
-       if ((i != generation) && (i != new_space))
+    for (i = 0; i < NUM_GENERATIONS; i++) {
+       if ((i != generation) && (i != new_space)) {
            scavenge_generation(i);
+       }
+    }
 
     /* Finally scavenge the new_space generation. Keep going until no
      * more objects are moved into the new generation */
@@ -5570,8 +3817,7 @@ garbage_collect_generation(int generation, int raise)
        scavenge_newspace_generation_one_scan(new_space);
 
        /* Flush the current regions, updating the tables. */
-       gc_alloc_update_page_tables(0, &boxed_region);
-       gc_alloc_update_page_tables(1, &unboxed_region);
+       gc_alloc_update_all_page_tables();
 
        bytes_allocated = bytes_allocated - old_bytes_allocated;
 
@@ -5585,8 +3831,7 @@ garbage_collect_generation(int generation, int raise)
     scan_weak_pointers();
 
     /* Flush the current regions, updating the tables. */
-    gc_alloc_update_page_tables(0, &boxed_region);
-    gc_alloc_update_page_tables(1, &unboxed_region);
+    gc_alloc_update_all_page_tables();
 
     /* Free the pages in oldspace, but not those marked dont_move. */
     bytes_freed = free_oldspace();
@@ -5643,18 +3888,19 @@ update_x86_dynamic_space_free_pointer(void)
     last_free_page = last_page+1;
 
     SetSymbolValue(ALLOCATION_POINTER,
-                  (lispobj)(((char *)heap_base) + last_free_page*4096));
+                  (lispobj)(((char *)heap_base) + last_free_page*4096),0);
     return 0; /* dummy value: return something ... */
 }
 
-/* GC all generations below last_gen, raising their objects to the
- * next generation until all generations below last_gen are empty.
- * Then if last_gen is due for a GC then GC it. In the special case
- * that last_gen==NUM_GENERATIONS, the last generation is always
- * GC'ed. The valid range for last_gen is: 0,1,...,NUM_GENERATIONS.
+/* GC all generations newer than last_gen, raising the objects in each
+ * to the next older generation - we finish when all generations below
+ * last_gen are empty.  Then if last_gen is due for a GC, or if
+ * last_gen==NUM_GENERATIONS (the scratch generation?  eh?) we GC that
+ * too.  The valid range for last_gen is: 0,1,...,NUM_GENERATIONS.
  *
- * The oldest generation to be GCed will always be
- * gencgc_oldest_gen_to_gc, partly ignoring last_gen if necessary. */
+ * We stop collecting at gencgc_oldest_gen_to_gc, even if this is less than
+ * last_gen (oh, and note that by default it is NUM_GENERATIONS-1) */
 void
 collect_garbage(unsigned last_gen)
 {
@@ -5663,8 +3909,6 @@ collect_garbage(unsigned last_gen)
     int gen_to_wp;
     int i;
 
-    boxed_region.free_pointer = current_region_free_pointer;
-
     FSHOW((stderr, "/entering collect_garbage(%d)\n", last_gen));
 
     if (last_gen > NUM_GENERATIONS) {
@@ -5675,12 +3919,11 @@ collect_garbage(unsigned last_gen)
     }
 
     /* Flush the alloc regions updating the tables. */
-    gc_alloc_update_page_tables(0, &boxed_region);
-    gc_alloc_update_page_tables(1, &unboxed_region);
+    gc_alloc_update_all_page_tables();
 
     /* Verify the new objects created by Lisp code. */
     if (pre_verify_gen_0) {
-       SHOW((stderr, "pre-checking generation 0\n"));
+       FSHOW((stderr, "pre-checking generation 0\n"));
        verify_generation(0);
     }
 
@@ -5761,27 +4004,23 @@ collect_garbage(unsigned last_gen)
        write_protect_generation_pages(gen_to_wp);
     }
 
-    /* Set gc_alloc back to generation 0. The current regions should
-     * be flushed after the above GCs */
+    /* Set gc_alloc() back to generation 0. The current regions should
+     * be flushed after the above GCs. */
     gc_assert((boxed_region.free_pointer - boxed_region.start_addr) == 0);
     gc_alloc_generation = 0;
 
     update_x86_dynamic_space_free_pointer();
-
-    /* This is now done by Lisp SCRUB-CONTROL-STACK in Lisp SUB-GC, so we
-     * needn't do it here: */
-    /*  zero_stack();*/
-
-    current_region_free_pointer = boxed_region.free_pointer;
-    current_region_end_addr = boxed_region.end_addr;
-
+    auto_gc_trigger = bytes_allocated + bytes_consed_between_gcs;
+    if(gencgc_verbose)
+       fprintf(stderr,"Next gc when %ld bytes have been consed\n",
+               auto_gc_trigger);
     SHOW("returning from collect_garbage");
 }
 
 /* This is called by Lisp PURIFY when it is finished. All live objects
  * will have been moved to the RO and Static heaps. The dynamic space
  * will need a full re-initialization. We don't bother having Lisp
- * PURIFY flush the current gc_alloc region, as the page_tables are
+ * PURIFY flush the current gc_alloc() region, as the page_tables are
  * re-initialized, and every page is zeroed to be sure. */
 void
 gc_free_heap(void)
@@ -5849,29 +4088,14 @@ gc_free_heap(void)
     if (gencgc_verbose > 1)
        print_generation_stats(0);
 
-    /* Initialize gc_alloc */
+    /* Initialize gc_alloc(). */
     gc_alloc_generation = 0;
-    boxed_region.first_page = 0;
-    boxed_region.last_page = -1;
-    boxed_region.start_addr = page_address(0);
-    boxed_region.free_pointer = page_address(0);
-    boxed_region.end_addr = page_address(0);
-
-    unboxed_region.first_page = 0;
-    unboxed_region.last_page = -1;
-    unboxed_region.start_addr = page_address(0);
-    unboxed_region.free_pointer = page_address(0);
-    unboxed_region.end_addr = page_address(0);
-
-#if 0 /* Lisp PURIFY is currently running on the C stack so don't do this. */
-    zero_stack();
-#endif
 
-    last_free_page = 0;
-    SetSymbolValue(ALLOCATION_POINTER, (lispobj)((char *)heap_base));
+    gc_set_region_empty(&boxed_region);
+    gc_set_region_empty(&unboxed_region);
 
-    current_region_free_pointer = boxed_region.free_pointer;
-    current_region_end_addr = boxed_region.end_addr;
+    last_free_page = 0;
+    SetSymbolValue(ALLOCATION_POINTER, (lispobj)((char *)heap_base),0);
 
     if (verify_after_free_heap) {
        /* Check whether purify has left any bad pointers. */
@@ -5887,6 +4111,9 @@ gc_init(void)
     int i;
 
     gc_init_tables();
+    scavtab[SIMPLE_VECTOR_WIDETAG] = scav_vector;
+    scavtab[WEAK_POINTER_WIDETAG] = scav_weak_pointer;
+    transother[SIMPLE_ARRAY_WIDETAG] = trans_boxed_large;
 
     heap_base = (void*)DYNAMIC_SPACE_START;
 
@@ -5902,7 +4129,9 @@ gc_init(void)
 
     bytes_allocated = 0;
 
-    /* Initialize the generations. */
+    /* Initialize the generations.
+     *
+     * FIXME: very similar to code in gc_free_heap(), should be shared */
     for (i = 0; i < NUM_GENERATIONS; i++) {
        generations[i].alloc_start_page = 0;
        generations[i].alloc_unboxed_start_page = 0;
@@ -5920,22 +4149,11 @@ gc_init(void)
 
     /* Initialize gc_alloc. */
     gc_alloc_generation = 0;
-    boxed_region.first_page = 0;
-    boxed_region.last_page = -1;
-    boxed_region.start_addr = page_address(0);
-    boxed_region.free_pointer = page_address(0);
-    boxed_region.end_addr = page_address(0);
-
-    unboxed_region.first_page = 0;
-    unboxed_region.last_page = -1;
-    unboxed_region.start_addr = page_address(0);
-    unboxed_region.free_pointer = page_address(0);
-    unboxed_region.end_addr = page_address(0);
+    gc_set_region_empty(&boxed_region);
+    gc_set_region_empty(&unboxed_region);
 
     last_free_page = 0;
 
-    current_region_free_pointer = boxed_region.free_pointer;
-    current_region_end_addr = boxed_region.end_addr;
 }
 
 /*  Pick up the dynamic space from after a core load.
@@ -5943,12 +4161,12 @@ gc_init(void)
  *  The ALLOCATION_POINTER points to the end of the dynamic space.
  *
  *  XX A scan is needed to identify the closest first objects for pages. */
-void
+static void
 gencgc_pickup_dynamic(void)
 {
     int page = 0;
     int addr = DYNAMIC_SPACE_START;
-    int alloc_ptr = SymbolValue(ALLOCATION_POINTER);
+    int alloc_ptr = SymbolValue(ALLOCATION_POINTER,0);
 
     /* Initialize the first region. */
     do {
@@ -5965,12 +4183,16 @@ gencgc_pickup_dynamic(void)
     generations[0].bytes_allocated = 4096*page;
     bytes_allocated = 4096*page;
 
-    current_region_free_pointer = boxed_region.free_pointer;
-    current_region_end_addr = boxed_region.end_addr;
 }
+
+void
+gc_initialize_pointers(void)
+{
+    gencgc_pickup_dynamic();
+}
+
+
 \f
-/* a counter for how deep we are in alloc(..) calls */
-int alloc_entered = 0;
 
 /* alloc(..) is the external interface for memory allocation. It
  * allocates to generation 0. It is not called from within the garbage
@@ -5982,168 +4204,63 @@ int alloc_entered = 0;
  * (E.g. the most significant word of a 2-word bignum in MOVE-FROM-UNSIGNED.)
  *
  * The check for a GC trigger is only performed when the current
- * region is full, so in most cases it's not needed. Further MAYBE-GC
- * is only called once because Lisp will remember "need to collect
- * garbage" and get around to it when it can. */
+ * region is full, so in most cases it's not needed. */
+
 char *
 alloc(int nbytes)
 {
+    struct thread *th=arch_os_get_current_thread();
+    struct alloc_region *region= 
+       th ? &(th->alloc_region) : &boxed_region; 
+    void *new_obj;
+    void *new_free_pointer;
+
     /* Check for alignment allocation problems. */
-    gc_assert((((unsigned)current_region_free_pointer & 0x7) == 0)
+    gc_assert((((unsigned)region->free_pointer & 0x7) == 0)
              && ((nbytes & 0x7) == 0));
-
-    if (SymbolValue(PSEUDO_ATOMIC_ATOMIC)) {/* if already in a pseudo atomic */
-       
-       void *new_free_pointer;
-
-    retry1:
-       if (alloc_entered) {
-           SHOW("alloc re-entered in already-pseudo-atomic case");
-       }
-       ++alloc_entered;
-
-       /* Check whether there is room in the current region. */
-       new_free_pointer = current_region_free_pointer + nbytes;
-
-       /* FIXME: Shouldn't we be doing some sort of lock here, to
-        * keep from getting screwed if an interrupt service routine
-        * allocates memory between the time we calculate new_free_pointer
-        * and the time we write it back to current_region_free_pointer?
-        * Perhaps I just don't understand pseudo-atomics..
-        *
-        * Perhaps I don't. It looks as though what happens is if we
-        * were interrupted any time during the pseudo-atomic
-        * interval (which includes now) we discard the allocated
-        * memory and try again. So, at least we don't return
-        * a memory area that was allocated out from underneath us
-        * by code in an ISR.
-        * Still, that doesn't seem to prevent
-        * current_region_free_pointer from getting corrupted:
-        *   We read current_region_free_pointer.
-        *   They read current_region_free_pointer.
-        *   They write current_region_free_pointer.
-        *   We write current_region_free_pointer, scribbling over
-        *     whatever they wrote. */
-
-       if (new_free_pointer <= boxed_region.end_addr) {
-           /* If so then allocate from the current region. */
-           void  *new_obj = current_region_free_pointer;
-           current_region_free_pointer = new_free_pointer;
-           alloc_entered--;
-           return((void *)new_obj);
-       }
-
-       if (auto_gc_trigger && bytes_allocated > auto_gc_trigger) {
-           /* Double the trigger. */
-           auto_gc_trigger *= 2;
-           alloc_entered--;
-           /* Exit the pseudo-atomic. */
-           SetSymbolValue(PSEUDO_ATOMIC_ATOMIC, make_fixnum(0));
-           if (SymbolValue(PSEUDO_ATOMIC_INTERRUPTED) != 0) {
-               /* Handle any interrupts that occurred during
-                * gc_alloc(..). */
-               do_pending_interrupt();
-           }
-           funcall0(SymbolFunction(MAYBE_GC));
-           /* Re-enter the pseudo-atomic. */
-           SetSymbolValue(PSEUDO_ATOMIC_INTERRUPTED, make_fixnum(0));
-           SetSymbolValue(PSEUDO_ATOMIC_ATOMIC, make_fixnum(1));
-           goto retry1;
-       }
-       /* Call gc_alloc. */
-       boxed_region.free_pointer = current_region_free_pointer;
-       {
-           void *new_obj = gc_alloc(nbytes);
-           current_region_free_pointer = boxed_region.free_pointer;
-           current_region_end_addr = boxed_region.end_addr;
-           alloc_entered--;
-           return (new_obj);
-       }
-    } else {
-       void *result;
-       void *new_free_pointer;
-
-    retry2:
-       /* At least wrap this allocation in a pseudo atomic to prevent
-        * gc_alloc from being re-entered. */
-       SetSymbolValue(PSEUDO_ATOMIC_INTERRUPTED, make_fixnum(0));
-       SetSymbolValue(PSEUDO_ATOMIC_ATOMIC, make_fixnum(1));
-
-       if (alloc_entered)
-           SHOW("alloc re-entered in not-already-pseudo-atomic case");
-       ++alloc_entered;
-
-       /* Check whether there is room in the current region. */
-       new_free_pointer = current_region_free_pointer + nbytes;
-
-       if (new_free_pointer <= boxed_region.end_addr) {
-           /* If so then allocate from the current region. */
-           void *new_obj = current_region_free_pointer;
-           current_region_free_pointer = new_free_pointer;
-           alloc_entered--;
-           SetSymbolValue(PSEUDO_ATOMIC_ATOMIC, make_fixnum(0));
-           if (SymbolValue(PSEUDO_ATOMIC_INTERRUPTED)) {
-               /* Handle any interrupts that occurred during
-                * gc_alloc(..). */
-               do_pending_interrupt();
-               goto retry2;
-           }
-
-           return((void *)new_obj);
-       }
-
-       /* KLUDGE: There's lots of code around here shared with the
-        * the other branch. Is there some way to factor out the
-        * duplicate code? -- WHN 19991129 */
-       if (auto_gc_trigger && bytes_allocated > auto_gc_trigger) {
-           /* Double the trigger. */
-           auto_gc_trigger *= 2;
-           alloc_entered--;
-           /* Exit the pseudo atomic. */
-           SetSymbolValue(PSEUDO_ATOMIC_ATOMIC, make_fixnum(0));
-           if (SymbolValue(PSEUDO_ATOMIC_INTERRUPTED) != 0) {
-               /* Handle any interrupts that occurred during
-                * gc_alloc(..); */
-               do_pending_interrupt();
-           }
-           funcall0(SymbolFunction(MAYBE_GC));
-           goto retry2;
-       }
-
-       /* Else call gc_alloc. */
-       boxed_region.free_pointer = current_region_free_pointer;
-       result = gc_alloc(nbytes);
-       current_region_free_pointer = boxed_region.free_pointer;
-       current_region_end_addr = boxed_region.end_addr;
-
-       alloc_entered--;
-       SetSymbolValue(PSEUDO_ATOMIC_ATOMIC, make_fixnum(0));
-       if (SymbolValue(PSEUDO_ATOMIC_INTERRUPTED) != 0) {
-           /* Handle any interrupts that occurred during
-            * gc_alloc(..). */
-           do_pending_interrupt();
-           goto retry2;
+    if(all_threads)
+       /* there are a few places in the C code that allocate data in the
+        * heap before Lisp starts.  This is before interrupts are enabled,
+        * so we don't need to check for pseudo-atomic */
+#ifdef LISP_FEATURE_SB_THREAD
+       if(!SymbolValue(PSEUDO_ATOMIC_ATOMIC,th)) {
+           register u32 fs;
+           fprintf(stderr, "fatal error in thread 0x%x, pid=%d\n",
+                   th,getpid());
+           __asm__("movl %fs,%0" : "=r" (fs)  : );
+           fprintf(stderr, "fs is %x, th->tls_cookie=%x (should be identical)\n",
+                   debug_get_fs(),th->tls_cookie);
+           lose("If you see this message before 2003.12.01, mail details to sbcl-devel\n");
        }
-
-       return result;
+#else
+    gc_assert(SymbolValue(PSEUDO_ATOMIC_ATOMIC,th));
+#endif
+    
+    /* maybe we can do this quickly ... */
+    new_free_pointer = region->free_pointer + nbytes;
+    if (new_free_pointer <= region->end_addr) {
+       new_obj = (void*)(region->free_pointer);
+       region->free_pointer = new_free_pointer;
+       return(new_obj);        /* yup */
     }
-}
-\f
-/*
- * noise to manipulate the gc trigger stuff
- */
-
-void
-set_auto_gc_trigger(os_vm_size_t dynamic_usage)
-{
-    auto_gc_trigger += dynamic_usage;
+    
+    /* we have to go the long way around, it seems.  Check whether 
+     * we should GC in the near future
+     */
+    if (auto_gc_trigger && bytes_allocated > auto_gc_trigger) {
+       /* set things up so that GC happens when we finish the PA
+        * section.  We only do this if there wasn't a pending handler
+        * already, in case it was a gc.  If it wasn't a GC, the next
+        * allocation will get us back to this point anyway, so no harm done
+        */
+       struct interrupt_data *data=th->interrupt_data;
+       if(!data->pending_handler) 
+           maybe_defer_handler(interrupt_maybe_gc_int,data,0,0,0);
+    }
+    new_obj = gc_alloc_with_region(nbytes,0,region,0);
+    return (new_obj);
 }
 
-void
-clear_auto_gc_trigger(void)
-{
-    auto_gc_trigger = 0;
-}
 \f
 /* Find the code object for the given pc, or return NULL on failure.
  *
@@ -6161,7 +4278,7 @@ component_ptr_from_pc(lispobj *pc)
        object = search_dynamic_space(pc);
 
     if (object) /* if we found something */
-       if (TypeOf(*object) == type_CodeHeader) /* if it's a code object */
+       if (widetag_of(*object) == CODE_HEADER_WIDETAG) /* if it's a code object */
            return(object);
 
     return (NULL);
@@ -6183,6 +4300,7 @@ void unhandled_sigmemoryfault(void);
  * Return true if this signal is a normal generational GC thing that
  * we were able to handle, or false if it was abnormal and control
  * should fall through to the general SIGSEGV/SIGBUS/whatever logic. */
+
 int
 gencgc_handle_wp_violation(void* fault_addr)
 {
@@ -6204,23 +4322,25 @@ gencgc_handle_wp_violation(void* fault_addr)
        return 0;
 
     } else {
-
-       /* The only acceptable reason for an signal like this from the
-        * heap is that the generational GC write-protected the page. */
-       if (page_table[page_index].write_protected != 1) {
-           lose("access failure in heap page not marked as write-protected");
+       if (page_table[page_index].write_protected) {
+           /* Unprotect the page. */
+           os_protect(page_address(page_index), PAGE_BYTES, OS_VM_PROT_ALL);
+           page_table[page_index].write_protected_cleared = 1;
+           page_table[page_index].write_protected = 0;
+       } else {  
+           /* The only acceptable reason for this signal on a heap
+            * access is that GENCGC write-protected the page.
+            * However, if two CPUs hit a wp page near-simultaneously,
+            * we had better not have the second one lose here if it
+            * does this test after the first one has already set wp=0
+            */
+           if(page_table[page_index].write_protected_cleared != 1) 
+               lose("fault in heap page not marked as write-protected");
        }
-       
-       /* Unprotect the page. */
-       os_protect(page_address(page_index), 4096, OS_VM_PROT_ALL);
-       page_table[page_index].write_protected = 0;
-       page_table[page_index].write_protected_cleared = 1;
-
        /* Don't worry, we can handle it. */
        return 1;
     }
 }
-
 /* This is to be called when we catch a SIGSEGV/SIGBUS, determine that
  * it's not just a case of the program hitting the write barrier, and
  * are about to let Lisp deal with it. It's basically just a
@@ -6228,3 +4348,23 @@ gencgc_handle_wp_violation(void* fault_addr)
 void
 unhandled_sigmemoryfault()
 {}
+
+void gc_alloc_update_all_page_tables(void)
+{
+    /* Flush the alloc regions updating the tables. */
+    struct thread *th;
+    for_each_thread(th) 
+        gc_alloc_update_page_tables(0, &th->alloc_region);
+    gc_alloc_update_page_tables(1, &unboxed_region);
+    gc_alloc_update_page_tables(0, &boxed_region);
+}
+void 
+gc_set_region_empty(struct alloc_region *region)
+{
+    region->first_page = 0;
+    region->last_page = -1;
+    region->start_addr = page_address(0);
+    region->free_pointer = page_address(0);
+    region->end_addr = page_address(0);
+}
+