0.9.1.59:
[sbcl.git] / src / runtime / gencgc.c
index c231ae3..0c0c98f 100644 (file)
@@ -27,8 +27,9 @@
 #include <stdio.h>
 #include <signal.h>
 #include <errno.h>
-#include "runtime.h"
+#include <string.h>
 #include "sbcl.h"
+#include "runtime.h"
 #include "os.h"
 #include "interr.h"
 #include "globals.h"
 #include "validate.h"
 #include "lispregs.h"
 #include "arch.h"
+#include "fixnump.h"
 #include "gc.h"
 #include "gc-internal.h"
 #include "thread.h"
 #include "genesis/vector.h"
 #include "genesis/weak-pointer.h"
 #include "genesis/simple-fun.h"
+#include "genesis/hash-table.h"
 
-#ifdef LISP_FEATURE_SB_THREAD
-#include <sys/ptrace.h>
-#include <linux/user.h>                /* threading is presently linux-only */
-#endif
-
-/* assembly language stub that executes trap_PendingInterrupt */
-void do_pending_interrupt(void);
+/* forward declarations */
+long gc_find_freeish_pages(long *restart_page_ptr, long nbytes, int unboxed);
+static void  gencgc_pickup_dynamic(void);
 
 \f
 /*
@@ -66,7 +65,7 @@ void do_pending_interrupt(void);
 boolean enable_page_protection = 1;
 
 /* Should we unmap a page and re-mmap it to have it zero filled? */
-#if defined(__FreeBSD__) || defined(__OpenBSD__)
+#if defined(__FreeBSD__) || defined(__OpenBSD__) || defined(__NetBSD__)
 /* comment from cmucl-2.4.8: This can waste a lot of swap on FreeBSD
  * so don't unmap there.
  *
@@ -80,7 +79,8 @@ boolean gencgc_unmap_zero = 1;
 #endif
 
 /* the minimum size (in bytes) for a large object*/
-unsigned large_object_size = 4 * 4096;
+unsigned large_object_size = 4 * PAGE_BYTES;
+
 \f
 /*
  * debugging
@@ -90,7 +90,11 @@ unsigned large_object_size = 4 * 4096;
 
 /* the verbosity level. All non-error messages are disabled at level 0;
  * and only a few rare messages are printed at level 1. */
-unsigned gencgc_verbose = (QSHOW ? 1 : 0);
+#ifdef QSHOW
+unsigned gencgc_verbose = 1;
+#else
+unsigned gencgc_verbose = 0;
+#endif
 
 /* FIXME: At some point enable the various error-checking things below
  * and see what they say. */
@@ -129,20 +133,15 @@ 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. */
-int from_space;
-int new_space;
+long from_space;
+long 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.
  * This helps quickly map between an address its page structure.
  * NUM_PAGES is set from the size of the dynamic space. */
@@ -152,23 +151,28 @@ struct page page_table[NUM_PAGES];
  * is needed. */
 static void *heap_base = NULL;
 
+#if N_WORD_BITS == 32
+ #define SIMPLE_ARRAY_WORD_WIDETAG SIMPLE_ARRAY_UNSIGNED_BYTE_32_WIDETAG
+#elif N_WORD_BITS == 64
+ #define SIMPLE_ARRAY_WORD_WIDETAG SIMPLE_ARRAY_UNSIGNED_BYTE_64_WIDETAG
+#endif
 
 /* Calculate the start address for the given page number. */
 inline void *
-page_address(int page_num)
+page_address(long page_num)
 {
-    return (heap_base + (page_num * 4096));
+    return (heap_base + (page_num * PAGE_BYTES));
 }
 
 /* Find the page index within the page_table for the given
  * address. Return -1 on failure. */
-inline int
+inline long
 find_page_index(void *addr)
 {
-    int index = addr-heap_base;
+    long index = addr-heap_base;
 
     if (index >= 0) {
-       index = ((unsigned int)index)/4096;
+       index = ((unsigned long)index)/PAGE_BYTES;
        if (index < NUM_PAGES)
            return (index);
     }
@@ -180,28 +184,28 @@ find_page_index(void *addr)
 struct generation {
 
     /* the first page that gc_alloc() checks on its next call */
-    int alloc_start_page;
+    long alloc_start_page;
 
     /* the first page that gc_alloc_unboxed() checks on its next call */
-    int alloc_unboxed_start_page;
+    long alloc_unboxed_start_page;
 
     /* the first page that gc_alloc_large (boxed) considers on its next
      * call. (Although it always allocates after the boxed_region.) */
-    int alloc_large_start_page;
+    long alloc_large_start_page;
 
     /* the first page that gc_alloc_large (unboxed) considers on its
      * next call. (Although it always allocates after the
      * current_unboxed_region.) */
-    int alloc_large_unboxed_start_page;
+    long alloc_large_unboxed_start_page;
 
     /* the bytes allocated to this generation */
-    int bytes_allocated;
+    long bytes_allocated;
 
     /* the number of bytes at which to trigger a GC */
-    int gc_trigger;
+    long gc_trigger;
 
     /* to calculate a new level for gc_trigger */
-    int bytes_consed_between_gc;
+    long bytes_consed_between_gc;
 
     /* the number of GCs since the last raise */
     int num_gc;
@@ -215,7 +219,7 @@ struct generation {
      * objects are added from a GC of a younger generation. Dividing by
      * the bytes_allocated will give the average age of the memory in
      * this generation since its last GC. */
-    int cum_sum_bytes_allocated;
+    long cum_sum_bytes_allocated;
 
     /* a minimum average memory age before a GC will occur helps
      * prevent a GC when a large number of new live objects have been
@@ -250,7 +254,7 @@ unsigned int  gencgc_oldest_gen_to_gc = NUM_GENERATIONS-1;
  * ALLOCATION_POINTER which is used by the room function to limit its
  * search of the heap. XX Gencgc obviously needs to be better
  * integrated with the Lisp code. */
-static int  last_free_page;
+static long  last_free_page;
 \f
 /* This lock is to prevent multiple threads from simultaneously
  * allocating new regions which overlap each other.  Note that the
@@ -268,14 +272,14 @@ static lispobj free_pages_lock=0;
 
 /* Count the number of pages which are write-protected within the
  * given generation. */
-static int
+static long
 count_write_protect_generation_pages(int generation)
 {
-    int i;
-    int count = 0;
+    long i;
+    long count = 0;
 
     for (i = 0; i < last_free_page; i++)
-       if ((page_table[i].allocated != FREE_PAGE)
+       if ((page_table[i].allocated != FREE_PAGE_FLAG)
            && (page_table[i].gen == generation)
            && (page_table[i].write_protected == 1))
            count++;
@@ -283,11 +287,11 @@ count_write_protect_generation_pages(int generation)
 }
 
 /* Count the number of pages within the given generation. */
-static int
+static long
 count_generation_pages(int generation)
 {
-    int i;
-    int count = 0;
+    long i;
+    long count = 0;
 
     for (i = 0; i < last_free_page; i++)
        if ((page_table[i].allocated != 0)
@@ -296,12 +300,12 @@ count_generation_pages(int generation)
     return count;
 }
 
-/* Count the number of dont_move pages. */
-static int
+#ifdef QSHOW
+static long
 count_dont_move_pages(void)
 {
-    int i;
-    int count = 0;
+    long i;
+    long count = 0;
     for (i = 0; i < last_free_page; i++) {
        if ((page_table[i].allocated != 0) && (page_table[i].dont_move != 0)) {
            ++count;
@@ -309,14 +313,15 @@ count_dont_move_pages(void)
     }
     return count;
 }
+#endif /* QSHOW */
 
 /* Work through the pages and add up the number of bytes used for the
  * given generation. */
-static int
+static long
 count_generation_bytes_allocated (int gen)
 {
-    int i;
-    int result = 0;
+    long i;
+    long 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;
@@ -336,6 +341,8 @@ 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
@@ -356,7 +363,7 @@ print_generation_stats(int verbose) /* FIXME: should take FILE argument */
 
     /* Print the heap stats. */
     fprintf(stderr,
-           "   Generation Boxed Unboxed LB   LUB    Alloc  Waste   Trig    WP  GCs Mem-age\n");
+           "   Gen Boxed Unboxed LB   LUB  !move  Alloc  Waste   Trig    WP  GCs Mem-age\n");
 
     for (i = 0; i < gens; i++) {
        int j;
@@ -364,22 +371,23 @@ print_generation_stats(int verbose) /* FIXME: should take FILE argument */
        int unboxed_cnt = 0;
        int large_boxed_cnt = 0;
        int large_unboxed_cnt = 0;
+       int pinned_cnt=0;
 
        for (j = 0; j < last_free_page; j++)
            if (page_table[j].gen == i) {
 
                /* Count the number of boxed pages within the given
                 * generation. */
-               if (page_table[j].allocated & BOXED_PAGE) {
+               if (page_table[j].allocated & BOXED_PAGE_FLAG) {
                    if (page_table[j].large_object)
                        large_boxed_cnt++;
                    else
                        boxed_cnt++;
                }
-
+               if(page_table[j].dont_move) pinned_cnt++;
                /* Count the number of unboxed pages within the given
                 * generation. */
-               if (page_table[j].allocated & UNBOXED_PAGE) {
+               if (page_table[j].allocated & UNBOXED_PAGE_FLAG) {
                    if (page_table[j].large_object)
                        large_unboxed_cnt++;
                    else
@@ -390,11 +398,12 @@ print_generation_stats(int verbose) /* FIXME: should take FILE argument */
        gc_assert(generations[i].bytes_allocated
                  == count_generation_bytes_allocated(i));
        fprintf(stderr,
-               "   %8d: %5d %5d %5d %5d %8d %5d %8d %4d %3d %7.4f\n",
+               "   %1d: %5d %5d %5d %5d %5d %8ld %5ld %8ld %4ld %3d %7.4f\n",
                i,
                boxed_cnt, unboxed_cnt, large_boxed_cnt, large_unboxed_cnt,
+               pinned_cnt,
                generations[i].bytes_allocated,
-               (count_generation_pages(i)*4096
+               (count_generation_pages(i)*PAGE_BYTES
                 - generations[i].bytes_allocated),
                generations[i].gc_trigger,
                count_write_protect_generation_pages(i),
@@ -419,7 +428,7 @@ print_generation_stats(int verbose) /* FIXME: should take FILE argument */
  * e.g. boxed/unboxed, generation, ages; there may need to be many
  * allocation regions.
  *
- * Each allocation region may be start within a partly used page. Many
+ * Each allocation region may start within a partly used page. Many
  * features of memory use are noted on a page wise basis, e.g. the
  * generation; so if a region starts within an existing allocated page
  * it must be consistent with this page.
@@ -488,12 +497,12 @@ static int gc_alloc_generation;
  * are allocated, although they will initially be empty.
  */
 static void
-gc_alloc_new_region(int nbytes, int unboxed, struct alloc_region *alloc_region)
+gc_alloc_new_region(long nbytes, int unboxed, struct alloc_region *alloc_region)
 {
-    int first_page;
-    int last_page;
-    int bytes_found;
-    int i;
+    long first_page;
+    long last_page;
+    long bytes_found;
+    long i;
 
     /*
     FSHOW((stderr,
@@ -505,7 +514,7 @@ 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,alloc_region);
+    get_spinlock(&free_pages_lock,(long) alloc_region);
     if (unboxed) {
        first_page =
            generations[gc_alloc_generation].alloc_unboxed_start_page;
@@ -513,9 +522,9 @@ gc_alloc_new_region(int nbytes, int unboxed, struct alloc_region *alloc_region)
        first_page =
            generations[gc_alloc_generation].alloc_start_page;
     }
-    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);
+    last_page=gc_find_freeish_pages(&first_page,nbytes,unboxed);
+    bytes_found=(PAGE_BYTES - page_table[first_page].bytes_used)
+           + PAGE_BYTES*(last_page-first_page);
 
     /* Set up the alloc_region. */
     alloc_region->first_page = first_page;
@@ -530,50 +539,50 @@ gc_alloc_new_region(int nbytes, int unboxed, struct alloc_region *alloc_region)
     /* The first page may have already been in use. */
     if (page_table[first_page].bytes_used == 0) {
        if (unboxed)
-           page_table[first_page].allocated = UNBOXED_PAGE;
+           page_table[first_page].allocated = UNBOXED_PAGE_FLAG;
        else
-           page_table[first_page].allocated = BOXED_PAGE;
+           page_table[first_page].allocated = BOXED_PAGE_FLAG;
        page_table[first_page].gen = gc_alloc_generation;
        page_table[first_page].large_object = 0;
        page_table[first_page].first_object_offset = 0;
     }
 
     if (unboxed)
-       gc_assert(page_table[first_page].allocated == UNBOXED_PAGE);
+       gc_assert(page_table[first_page].allocated == UNBOXED_PAGE_FLAG);
     else
-       gc_assert(page_table[first_page].allocated == BOXED_PAGE);
-    page_table[first_page].allocated |= OPEN_REGION_PAGE; 
+       gc_assert(page_table[first_page].allocated == BOXED_PAGE_FLAG);
+    page_table[first_page].allocated |= OPEN_REGION_PAGE_FLAG; 
 
     gc_assert(page_table[first_page].gen == gc_alloc_generation);
     gc_assert(page_table[first_page].large_object == 0);
 
     for (i = first_page+1; i <= last_page; i++) {
        if (unboxed)
-           page_table[i].allocated = UNBOXED_PAGE;
+           page_table[i].allocated = UNBOXED_PAGE_FLAG;
        else
-           page_table[i].allocated = BOXED_PAGE;
+           page_table[i].allocated = BOXED_PAGE_FLAG;
        page_table[i].gen = gc_alloc_generation;
        page_table[i].large_object = 0;
        /* This may not be necessary for unboxed regions (think it was
         * broken before!) */
        page_table[i].first_object_offset =
            alloc_region->start_addr - page_address(i);
-       page_table[i].allocated |= OPEN_REGION_PAGE ;
+       page_table[i].allocated |= OPEN_REGION_PAGE_FLAG ;
     }
     /* 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),
+                      (lispobj)(((char *)heap_base) + last_free_page*PAGE_BYTES),
                       0);
     }
-    free_pages_lock=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++) {
+       long *p;
+       for (p = (long *)alloc_region->start_addr;
+            p < (long *)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
@@ -603,22 +612,22 @@ gc_alloc_new_region(int nbytes, int unboxed, struct alloc_region *alloc_region)
  * scavenge of a generation. */
 #define NUM_NEW_AREAS 512
 static int record_new_objects = 0;
-static int new_areas_ignore_page;
+static long new_areas_ignore_page;
 struct new_area {
-    int  page;
-    int  offset;
-    int  size;
+    long  page;
+    long  offset;
+    long  size;
 };
 static struct new_area (*new_areas)[];
-static int new_areas_index;
-int max_new_areas;
+static long new_areas_index;
+long max_new_areas;
 
 /* Add a new area to new_areas. */
 static void
-add_new_area(int first_page, int offset, int size)
+add_new_area(long first_page, long offset, long size)
 {
     unsigned new_area_start,c;
-    int i;
+    long i;
 
     /* Ignore if full. */
     if (new_areas_index >= NUM_NEW_AREAS)
@@ -637,13 +646,13 @@ add_new_area(int first_page, int offset, int size)
        gc_abort();
     }
 
-    new_area_start = 4096*first_page + offset;
+    new_area_start = PAGE_BYTES*first_page + offset;
 
     /* Search backwards for a prior area that this follows from. If
        found this will save adding a new area. */
     for (i = new_areas_index-1, c = 0; (i >= 0) && (c < 8); i--, c++) {
        unsigned area_end =
-           4096*((*new_areas)[i].page)
+           PAGE_BYTES*((*new_areas)[i].page)
            + (*new_areas)[i].offset
            + (*new_areas)[i].size;
        /*FSHOW((stderr,
@@ -677,7 +686,7 @@ 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
@@ -687,19 +696,14 @@ add_new_area(int first_page, int offset, int size)
 void
 gc_alloc_update_page_tables(int unboxed, struct alloc_region *alloc_region)
 {
-    int more;
-    int first_page;
-    int next_page;
-    int bytes_used;
-    int orig_first_page_bytes_used;
-    int region_size;
-    int byte_cnt;
+    long more;
+    long first_page;
+    long next_page;
+    long bytes_used;
+    long orig_first_page_bytes_used;
+    long region_size;
+    long byte_cnt;
 
-    /*
-    FSHOW((stderr,
-          "/gc_alloc_update_page_tables() to gen %d:\n",
-          gc_alloc_generation));
-    */
 
     first_page = alloc_region->first_page;
 
@@ -709,7 +713,7 @@ gc_alloc_update_page_tables(int unboxed, struct alloc_region *alloc_region)
 
     next_page = first_page+1;
 
-    get_spinlock(&free_pages_lock,alloc_region);
+    get_spinlock(&free_pages_lock,(long) 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;
@@ -724,12 +728,12 @@ 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);
+       page_table[first_page].allocated &= ~(OPEN_REGION_PAGE_FLAG);
 
        if (unboxed)
-           gc_assert(page_table[first_page].allocated == UNBOXED_PAGE);
+           gc_assert(page_table[first_page].allocated == UNBOXED_PAGE_FLAG);
        else
-           gc_assert(page_table[first_page].allocated == BOXED_PAGE);
+           gc_assert(page_table[first_page].allocated == BOXED_PAGE_FLAG);
        gc_assert(page_table[first_page].gen == gc_alloc_generation);
        gc_assert(page_table[first_page].large_object == 0);
 
@@ -738,8 +742,8 @@ gc_alloc_update_page_tables(int unboxed, struct alloc_region *alloc_region)
        /* Calculate the number of bytes used in this page. This is not
         * always the number of new bytes, unless it was free. */
        more = 0;
-       if ((bytes_used = (alloc_region->free_pointer - page_address(first_page)))>4096) {
-           bytes_used = 4096;
+       if ((bytes_used = (alloc_region->free_pointer - page_address(first_page)))>PAGE_BYTES) {
+           bytes_used = PAGE_BYTES;
            more = 1;
        }
        page_table[first_page].bytes_used = bytes_used;
@@ -750,11 +754,11 @@ 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);
+           page_table[next_page].allocated &= ~(OPEN_REGION_PAGE_FLAG);
            if (unboxed)
-               gc_assert(page_table[next_page].allocated == UNBOXED_PAGE);
+               gc_assert(page_table[next_page].allocated==UNBOXED_PAGE_FLAG);
            else
-               gc_assert(page_table[next_page].allocated == BOXED_PAGE);
+               gc_assert(page_table[next_page].allocated == BOXED_PAGE_FLAG);
            gc_assert(page_table[next_page].bytes_used == 0);
            gc_assert(page_table[next_page].gen == gc_alloc_generation);
            gc_assert(page_table[next_page].large_object == 0);
@@ -765,8 +769,8 @@ gc_alloc_update_page_tables(int unboxed, struct alloc_region *alloc_region)
            /* Calculate the number of bytes used in this page. */
            more = 0;
            if ((bytes_used = (alloc_region->free_pointer
-                              - page_address(next_page)))>4096) {
-               bytes_used = 4096;
+                              - page_address(next_page)))>PAGE_BYTES) {
+               bytes_used = PAGE_BYTES;
                more = 1;
            }
            page_table[next_page].bytes_used = bytes_used;
@@ -802,61 +806,37 @@ 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);
+       page_table[first_page].allocated &= ~(OPEN_REGION_PAGE_FLAG);
        if (page_table[first_page].bytes_used == 0)
-           page_table[first_page].allocated = FREE_PAGE;
+           page_table[first_page].allocated = FREE_PAGE_FLAG;
     }
 
     /* Unallocate any unused pages. */
     while (next_page <= alloc_region->last_page) {
        gc_assert(page_table[next_page].bytes_used == 0);
-       page_table[next_page].allocated = FREE_PAGE;
+       page_table[next_page].allocated = FREE_PAGE_FLAG;
        next_page++;
     }
-    free_pages_lock=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);
+static inline void *gc_quick_alloc(long nbytes);
 
 /* Allocate a possibly large object. */
 void *
-gc_alloc_large(int nbytes, int unboxed, struct alloc_region *alloc_region)
+gc_alloc_large(long nbytes, int unboxed, struct alloc_region *alloc_region)
 {
-    int first_page;
-    int last_page;
-    int orig_first_page_bytes_used;
-    int byte_cnt;
-    int more;
-    int bytes_used;
-    int next_page;
-    int large = (nbytes >= large_object_size);
+    long first_page;
+    long last_page;
+    long orig_first_page_bytes_used;
+    long byte_cnt;
+    long more;
+    long bytes_used;
+    long next_page;
 
-    /*
-    if (nbytes > 200000)
-       FSHOW((stderr, "/alloc_large %d\n", nbytes));
-    */
-
-    /*
-    FSHOW((stderr,
-          "/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 allocate it in the current region. */
-    if (!large
-       && ((alloc_region->end_addr-alloc_region->free_pointer) >= nbytes))
-       return gc_quick_alloc(nbytes);
-
-    /* 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. */
-
-    get_spinlock(&free_pages_lock,alloc_region);
+    get_spinlock(&free_pages_lock,(long) alloc_region);
 
     if (unboxed) {
        first_page =
@@ -868,7 +848,7 @@ gc_alloc_large(int nbytes, int unboxed, struct alloc_region *alloc_region)
        first_page = alloc_region->last_page+1;
     }
 
-    last_page=gc_find_freeish_pages(&first_page,nbytes,unboxed,0);
+    last_page=gc_find_freeish_pages(&first_page,nbytes,unboxed);
 
     gc_assert(first_page > alloc_region->last_page);
     if (unboxed)
@@ -884,28 +864,28 @@ gc_alloc_large(int nbytes, int unboxed, struct alloc_region *alloc_region)
      * first_object_offset. */
     if (page_table[first_page].bytes_used == 0) {
        if (unboxed)
-           page_table[first_page].allocated = UNBOXED_PAGE;
+           page_table[first_page].allocated = UNBOXED_PAGE_FLAG;
        else
-           page_table[first_page].allocated = BOXED_PAGE;
+           page_table[first_page].allocated = BOXED_PAGE_FLAG;
        page_table[first_page].gen = gc_alloc_generation;
        page_table[first_page].first_object_offset = 0;
-       page_table[first_page].large_object = large;
+       page_table[first_page].large_object = 1;
     }
 
     if (unboxed)
-       gc_assert(page_table[first_page].allocated == UNBOXED_PAGE);
+       gc_assert(page_table[first_page].allocated == UNBOXED_PAGE_FLAG);
     else
-       gc_assert(page_table[first_page].allocated == BOXED_PAGE);
+       gc_assert(page_table[first_page].allocated == BOXED_PAGE_FLAG);
     gc_assert(page_table[first_page].gen == gc_alloc_generation);
-    gc_assert(page_table[first_page].large_object == large);
+    gc_assert(page_table[first_page].large_object == 1);
 
     byte_cnt = 0;
 
     /* Calc. the number of bytes used in this page. This is not
      * always the number of new bytes, unless it was free. */
     more = 0;
-    if ((bytes_used = nbytes+orig_first_page_bytes_used) > 4096) {
-       bytes_used = 4096;
+    if ((bytes_used = nbytes+orig_first_page_bytes_used) > PAGE_BYTES) {
+       bytes_used = PAGE_BYTES;
        more = 1;
     }
     page_table[first_page].bytes_used = bytes_used;
@@ -917,27 +897,28 @@ gc_alloc_large(int nbytes, int unboxed, struct alloc_region *alloc_region)
      * first_object_offset pointer to the start of the region, and
      * set the bytes_used. */
     while (more) {
-       gc_assert(page_table[next_page].allocated == FREE_PAGE);
+       gc_assert(page_table[next_page].allocated == FREE_PAGE_FLAG);
        gc_assert(page_table[next_page].bytes_used == 0);
        if (unboxed)
-           page_table[next_page].allocated = UNBOXED_PAGE;
+           page_table[next_page].allocated = UNBOXED_PAGE_FLAG;
        else
-           page_table[next_page].allocated = BOXED_PAGE;
+           page_table[next_page].allocated = BOXED_PAGE_FLAG;
        page_table[next_page].gen = gc_alloc_generation;
-       page_table[next_page].large_object = large;
+       page_table[next_page].large_object = 1;
 
        page_table[next_page].first_object_offset =
-           orig_first_page_bytes_used - 4096*(next_page-first_page);
+           orig_first_page_bytes_used - PAGE_BYTES*(next_page-first_page);
 
        /* Calculate the number of bytes used in this page. */
        more = 0;
-       if ((bytes_used=(nbytes+orig_first_page_bytes_used)-byte_cnt) > 4096) {
-           bytes_used = 4096;
+       if ((bytes_used=(nbytes+orig_first_page_bytes_used)-byte_cnt) > PAGE_BYTES) {
+           bytes_used = PAGE_BYTES;
            more = 1;
        }
        page_table[next_page].bytes_used = bytes_used;
+       page_table[next_page].write_protected=0;
+       page_table[next_page].dont_move=0;
        byte_cnt += bytes_used;
-
        next_page++;
     }
 
@@ -954,65 +935,54 @@ gc_alloc_large(int nbytes, int unboxed, struct alloc_region *alloc_region)
     if (last_page+1 > last_free_page) {
        last_free_page = last_page+1;
        SetSymbolValue(ALLOCATION_POINTER,
-                      (lispobj)(((char *)heap_base) + last_free_page*4096),0);
+                      (lispobj)(((char *)heap_base) + last_free_page*PAGE_BYTES),0);
     }
-    free_pages_lock=0;
+    release_spinlock(&free_pages_lock);
 
     return((void *)(page_address(first_page)+orig_first_page_bytes_used));
 }
 
-int
-gc_find_freeish_pages(int *restart_page_ptr, int nbytes, int unboxed, struct alloc_region *alloc_region)
+long
+gc_find_freeish_pages(long *restart_page_ptr, long nbytes, int unboxed)
 {
-    /* 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);
-
+    long first_page;
+    long last_page;
+    long region_size;
+    long restart_page=*restart_page_ptr;
+    long bytes_found;
+    long num_pages;
+    long large_p=(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. */
+    /* 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. */
 
     do {
        first_page = restart_page;
-       if (large)              
+       if (large_p)            
            while ((first_page < NUM_PAGES)
-                  && (page_table[first_page].allocated != FREE_PAGE))
+                  && (page_table[first_page].allocated != FREE_PAGE_FLAG))
                first_page++;
        else
            while (first_page < NUM_PAGES) {
-               if(page_table[first_page].allocated == FREE_PAGE)
+               if(page_table[first_page].allocated == FREE_PAGE_FLAG)
                    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)) &&
+                   (unboxed ? UNBOXED_PAGE_FLAG : BOXED_PAGE_FLAG)) &&
                   (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].bytes_used < (PAGE_BYTES-32)) &&
                   (page_table[first_page].write_protected == 0) &&
-                  (page_table[first_page].dont_move == 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",
+                   "Argh! gc_find_free_space failed (first_page), nbytes=%ld.\n",
                    nbytes);
            print_generation_stats(1);
            lose(NULL);
@@ -1021,20 +991,20 @@ gc_find_freeish_pages(int *restart_page_ptr, int nbytes, int unboxed, struct all
        gc_assert(page_table[first_page].write_protected == 0);
 
        last_page = first_page;
-       bytes_found = 4096 - page_table[first_page].bytes_used;
+       bytes_found = PAGE_BYTES - page_table[first_page].bytes_used;
        num_pages = 1;
        while (((bytes_found < nbytes) 
-               || (alloc_region && (num_pages < 2)))
+               || (!large_p && (num_pages < 2)))
               && (last_page < (NUM_PAGES-1))
-              && (page_table[last_page+1].allocated == FREE_PAGE)) {
+              && (page_table[last_page+1].allocated == FREE_PAGE_FLAG)) {
            last_page++;
            num_pages++;
-           bytes_found += 4096;
+           bytes_found += PAGE_BYTES;
            gc_assert(page_table[last_page].write_protected == 0);
        }
 
-       region_size = (4096 - page_table[first_page].bytes_used)
-           + 4096*(last_page-first_page);
+       region_size = (PAGE_BYTES - page_table[first_page].bytes_used)
+           + PAGE_BYTES*(last_page-first_page);
 
        gc_assert(bytes_found == region_size);
        restart_page = last_page + 1;
@@ -1043,7 +1013,7 @@ gc_find_freeish_pages(int *restart_page_ptr, int nbytes, int unboxed, struct all
     /* 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",
+               "Argh! gc_find_freeish_pages failed (restart_page), nbytes=%ld.\n",
                nbytes);
        print_generation_stats(1);
        lose(NULL);
@@ -1053,20 +1023,23 @@ gc_find_freeish_pages(int *restart_page_ptr, int nbytes, int unboxed, struct all
 }
 
 /* Allocate bytes.  All the rest of the special-purpose allocation
- * functions will eventually call this (instead of just duplicating
- * parts of its code) */
+ * functions will eventually call this  */
 
 void *
-gc_alloc_with_region(int nbytes,int unboxed_p, struct alloc_region *my_region,
+gc_alloc_with_region(long nbytes,int unboxed_p, struct alloc_region *my_region,
                     int quick_p)
 {
     void *new_free_pointer;
 
-    /* FSHOW((stderr, "/gc_alloc %d\n", nbytes)); */
+    if(nbytes>=large_object_size)
+       return gc_alloc_large(nbytes,unboxed_p,my_region);
 
     /* Check whether there is room in the current alloc region. */
     new_free_pointer = my_region->free_pointer + nbytes;
 
+    /* fprintf(stderr, "alloc %d bytes from %p to %p\n", nbytes,
+       my_region->free_pointer, new_free_pointer); */
+
     if (new_free_pointer <= my_region->end_addr) {
        /* If so then allocate from the current alloc region. */
        void *new_obj = my_region->free_pointer;
@@ -1085,126 +1058,63 @@ gc_alloc_with_region(int nbytes,int unboxed_p, struct alloc_region *my_region,
        return((void *)new_obj);
     }
 
-    /* Else not enough free space in the current region. */
-
-    /* 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 ((my_region->end_addr-my_region->free_pointer) > 32)
-       return gc_alloc_large(nbytes, unboxed_p, my_region);
-
-    /* Else find a new region. */
+    /* Else not enough free space in the current region: retry with a
+     * new region. */
 
-    /* Finished with the current region. */
     gc_alloc_update_page_tables(unboxed_p, my_region);
-
-    /* Set up a new 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 = my_region->free_pointer + nbytes;
-
-    if (new_free_pointer <= my_region->end_addr) {
-       /* If so then allocate from the current region. */
-       void *new_obj = my_region->free_pointer;
-       my_region->free_pointer = new_free_pointer;
-       /* Check whether the current region is almost empty. */
-       if ((my_region->end_addr - my_region->free_pointer) <= 32) {
-           /* If so find, finished with the current region. */
-           gc_alloc_update_page_tables(unboxed_p, my_region);
-
-           /* Set up a new region. */
-           gc_alloc_new_region(32, unboxed_p, my_region);
-       }
-
-       return((void *)new_obj);
-    }
-
-    /* shouldn't happen */
-    gc_assert(0);
-    return((void *) NIL); /* dummy value: return something ... */
+    return gc_alloc_with_region(nbytes,unboxed_p,my_region,0);
 }
 
+/* these are only used during GC: all allocation from the mutator calls
+ * alloc() -> gc_alloc_with_region() with the appropriate per-thread 
+ * region */
+
 void *
-gc_general_alloc(int nbytes,int unboxed_p,int quick_p)
+gc_general_alloc(long nbytes,int unboxed_p,int quick_p)
 {
     struct alloc_region *my_region = 
       unboxed_p ? &unboxed_region : &boxed_region;
     return gc_alloc_with_region(nbytes,unboxed_p, my_region,quick_p);
 }
 
-
-
-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 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)
+gc_quick_alloc(long nbytes)
 {
     return gc_general_alloc(nbytes,ALLOC_BOXED,ALLOC_QUICK);
 }
 
-/* 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 */
-
 static inline void *
-gc_quick_alloc_large(int nbytes)
+gc_quick_alloc_large(long 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);
+    return gc_general_alloc(nbytes,ALLOC_BOXED,ALLOC_QUICK);
 }
 
 static inline void *
-gc_alloc_unboxed(int nbytes)
+gc_alloc_unboxed(long nbytes)
 {
     return gc_general_alloc(nbytes,ALLOC_UNBOXED,0);
 }
 
 static inline void *
-gc_quick_alloc_unboxed(int nbytes)
+gc_quick_alloc_unboxed(long 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 general gc_alloc_unboxed() to do the job.
- *
- * A pointer to the start of the object is returned. */
 static inline void *
-gc_quick_alloc_large_unboxed(int nbytes)
+gc_quick_alloc_large_unboxed(long nbytes)
 {
-    if (nbytes >= large_object_size)
-       return gc_alloc_large(nbytes,ALLOC_UNBOXED,&unboxed_region);
-    else
-       return gc_quick_alloc_unboxed(nbytes);
+    return gc_general_alloc(nbytes,ALLOC_UNBOXED,ALLOC_QUICK);
 }
 \f
 /*
  * scavenging/transporting routines derived from gc.c in CMU CL ca. 18b
  */
 
-extern int (*scavtab[256])(lispobj *where, lispobj object);
+extern long (*scavtab[256])(lispobj *where, lispobj object);
 extern lispobj (*transother[256])(lispobj object);
-extern int (*sizetab[256])(lispobj *where);
+extern long (*sizetab[256])(lispobj *where);
 
 /* 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
@@ -1213,19 +1123,18 @@ extern int (*sizetab[256])(lispobj *where);
  * Vectors may have shrunk. If the object is not copied the space
  * needs to be reclaimed, and the page_tables corrected. */
 lispobj
-copy_large_object(lispobj object, int nwords)
+copy_large_object(lispobj object, long nwords)
 {
     int tag;
     lispobj *new;
-    lispobj *source, *dest;
-    int first_page;
+    long first_page;
 
     gc_assert(is_lisp_pointer(object));
     gc_assert(from_space_p(object));
     gc_assert((nwords & 0x01) == 0);
 
 
-    /* Check whether it's a large object. */
+    /* Check whether it's in a large object region. */
     first_page = find_page_index((void *)object);
     gc_assert(first_page >= 0);
 
@@ -1233,10 +1142,10 @@ copy_large_object(lispobj object, int nwords)
 
        /* Promote the object. */
 
-       int remaining_bytes;
-       int next_page;
-       int bytes_freed;
-       int old_bytes_used;
+       long remaining_bytes;
+       long next_page;
+       long bytes_freed;
+       long old_bytes_used;
 
        /* Note: Any page write-protection must be removed, else a
         * later scavenge_newspace may incorrectly not scavenge these
@@ -1247,24 +1156,24 @@ copy_large_object(lispobj object, int nwords)
        gc_assert(page_table[first_page].first_object_offset == 0);
 
        next_page = first_page;
-       remaining_bytes = nwords*4;
-       while (remaining_bytes > 4096) {
+       remaining_bytes = nwords*N_WORD_BYTES;
+       while (remaining_bytes > PAGE_BYTES) {
            gc_assert(page_table[next_page].gen == from_space);
-           gc_assert(page_table[next_page].allocated == BOXED_PAGE);
+           gc_assert(page_table[next_page].allocated == BOXED_PAGE_FLAG);
            gc_assert(page_table[next_page].large_object);
            gc_assert(page_table[next_page].first_object_offset==
-                     -4096*(next_page-first_page));
-           gc_assert(page_table[next_page].bytes_used == 4096);
+                     -PAGE_BYTES*(next_page-first_page));
+           gc_assert(page_table[next_page].bytes_used == PAGE_BYTES);
 
            page_table[next_page].gen = new_space;
 
            /* Remove any write-protection. We should be able to rely
             * on the write-protect flag to avoid redundant calls. */
            if (page_table[next_page].write_protected) {
-               os_protect(page_address(next_page), 4096, OS_VM_PROT_ALL);
+               os_protect(page_address(next_page), PAGE_BYTES, OS_VM_PROT_ALL);
                page_table[next_page].write_protected = 0;
            }
-           remaining_bytes -= 4096;
+           remaining_bytes -= PAGE_BYTES;
            next_page++;
        }
 
@@ -1275,7 +1184,7 @@ 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_FLAG);
 
        /* Adjust the bytes_used. */
        old_bytes_used = page_table[next_page].bytes_used;
@@ -1285,12 +1194,12 @@ copy_large_object(lispobj object, int nwords)
 
        /* Free any remaining pages; needs care. */
        next_page++;
-       while ((old_bytes_used == 4096) &&
+       while ((old_bytes_used == PAGE_BYTES) &&
               (page_table[next_page].gen == from_space) &&
-              (page_table[next_page].allocated == BOXED_PAGE) &&
+              (page_table[next_page].allocated == BOXED_PAGE_FLAG) &&
               page_table[next_page].large_object &&
               (page_table[next_page].first_object_offset ==
-               -(next_page - first_page)*4096)) {
+               -(next_page - first_page)*PAGE_BYTES)) {
            /* 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
@@ -1298,18 +1207,19 @@ copy_large_object(lispobj object, int nwords)
            gc_assert(page_table[next_page].write_protected == 0);
 
            old_bytes_used = page_table[next_page].bytes_used;
-           page_table[next_page].allocated = FREE_PAGE;
+           page_table[next_page].allocated = FREE_PAGE_FLAG;
            page_table[next_page].bytes_used = 0;
            bytes_freed += old_bytes_used;
            next_page++;
        }
 
-       generations[from_space].bytes_allocated -= 4*nwords + bytes_freed;
-       generations[new_space].bytes_allocated += 4*nwords;
+       generations[from_space].bytes_allocated -= N_WORD_BYTES*nwords +
+         bytes_freed;
+       generations[new_space].bytes_allocated += N_WORD_BYTES*nwords;
        bytes_allocated -= bytes_freed;
 
        /* Add the region to the new_areas if requested. */
-       add_new_area(first_page,0,nwords*4);
+       add_new_area(first_page,0,nwords*N_WORD_BYTES);
 
        return(object);
     } else {
@@ -1317,19 +1227,9 @@ copy_large_object(lispobj object, int nwords)
        tag = lowtag_of(object);
 
        /* Allocate space. */
-       new = gc_quick_alloc_large(nwords*4);
-
-       dest = new;
-       source = (lispobj *) native_pointer(object);
-
-       /* Copy the object. */
-       while (nwords > 0) {
-           dest[0] = source[0];
-           dest[1] = source[1];
-           dest += 2;
-           source += 2;
-           nwords -= 2;
-       }
+       new = gc_quick_alloc_large(nwords*N_WORD_BYTES);
+
+       memcpy(new,native_pointer(object),nwords*N_WORD_BYTES);
 
        /* Return Lisp pointer of new object. */
        return ((lispobj) new) | tag;
@@ -1338,11 +1238,10 @@ copy_large_object(lispobj object, int nwords)
 
 /* to copy unboxed objects */
 lispobj
-copy_unboxed_object(lispobj object, int nwords)
+copy_unboxed_object(lispobj object, long nwords)
 {
-    int tag;
+    long tag;
     lispobj *new;
-    lispobj *source, *dest;
 
     gc_assert(is_lisp_pointer(object));
     gc_assert(from_space_p(object));
@@ -1352,19 +1251,9 @@ copy_unboxed_object(lispobj object, int nwords)
     tag = lowtag_of(object);
 
     /* Allocate space. */
-    new = gc_quick_alloc_unboxed(nwords*4);
-
-    dest = new;
-    source = (lispobj *) native_pointer(object);
-
-    /* Copy the object. */
-    while (nwords > 0) {
-       dest[0] = source[0];
-       dest[1] = source[1];
-       dest += 2;
-       source += 2;
-       nwords -= 2;
-    }
+    new = gc_quick_alloc_unboxed(nwords*N_WORD_BYTES);
+
+    memcpy(new,native_pointer(object),nwords*N_WORD_BYTES);
 
     /* Return Lisp pointer of new object. */
     return ((lispobj) new) | tag;
@@ -1382,19 +1271,18 @@ 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 */
 lispobj
-copy_large_unboxed_object(lispobj object, int nwords)
+copy_large_unboxed_object(lispobj object, long nwords)
 {
     int tag;
     lispobj *new;
-    lispobj *source, *dest;
-    int first_page;
+    long first_page;
 
     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_unboxed_object: %d bytes\n", nwords*4));
+       FSHOW((stderr, "/copy_large_unboxed_object: %d bytes\n", nwords*N_WORD_BYTES));
 
     /* Check whether it's a large object. */
     first_page = find_page_index((void *)object);
@@ -1404,27 +1292,27 @@ copy_large_unboxed_object(lispobj object, int nwords)
        /* Promote the object. Note: Unboxed objects may have been
         * allocated to a BOXED region so it may be necessary to
         * change the region to UNBOXED. */
-       int remaining_bytes;
-       int next_page;
-       int bytes_freed;
-       int old_bytes_used;
+       long remaining_bytes;
+       long next_page;
+       long bytes_freed;
+       long old_bytes_used;
 
        gc_assert(page_table[first_page].first_object_offset == 0);
 
        next_page = first_page;
-       remaining_bytes = nwords*4;
-       while (remaining_bytes > 4096) {
+       remaining_bytes = nwords*N_WORD_BYTES;
+       while (remaining_bytes > PAGE_BYTES) {
            gc_assert(page_table[next_page].gen == from_space);
-           gc_assert((page_table[next_page].allocated == UNBOXED_PAGE)
-                     || (page_table[next_page].allocated == BOXED_PAGE));
+           gc_assert((page_table[next_page].allocated == UNBOXED_PAGE_FLAG)
+                     || (page_table[next_page].allocated == BOXED_PAGE_FLAG));
            gc_assert(page_table[next_page].large_object);
            gc_assert(page_table[next_page].first_object_offset==
-                     -4096*(next_page-first_page));
-           gc_assert(page_table[next_page].bytes_used == 4096);
+                     -PAGE_BYTES*(next_page-first_page));
+           gc_assert(page_table[next_page].bytes_used == PAGE_BYTES);
 
            page_table[next_page].gen = new_space;
-           page_table[next_page].allocated = UNBOXED_PAGE;
-           remaining_bytes -= 4096;
+           page_table[next_page].allocated = UNBOXED_PAGE_FLAG;
+           remaining_bytes -= PAGE_BYTES;
            next_page++;
        }
 
@@ -1435,7 +1323,7 @@ copy_large_unboxed_object(lispobj object, int nwords)
        gc_assert(page_table[next_page].bytes_used >= remaining_bytes);
 
        page_table[next_page].gen = new_space;
-       page_table[next_page].allocated = UNBOXED_PAGE;
+       page_table[next_page].allocated = UNBOXED_PAGE_FLAG;
 
        /* Adjust the bytes_used. */
        old_bytes_used = page_table[next_page].bytes_used;
@@ -1445,13 +1333,13 @@ copy_large_unboxed_object(lispobj object, int nwords)
 
        /* Free any remaining pages; needs care. */
        next_page++;
-       while ((old_bytes_used == 4096) &&
+       while ((old_bytes_used == PAGE_BYTES) &&
               (page_table[next_page].gen == from_space) &&
-              ((page_table[next_page].allocated == UNBOXED_PAGE)
-               || (page_table[next_page].allocated == BOXED_PAGE)) &&
+              ((page_table[next_page].allocated == UNBOXED_PAGE_FLAG)
+               || (page_table[next_page].allocated == BOXED_PAGE_FLAG)) &&
               page_table[next_page].large_object &&
               (page_table[next_page].first_object_offset ==
-               -(next_page - first_page)*4096)) {
+               -(next_page - first_page)*PAGE_BYTES)) {
            /* Checks out OK, free the page. Don't need to both zeroing
             * pages as this should have been done before shrinking the
             * object. These pages shouldn't be write-protected, even if
@@ -1459,7 +1347,7 @@ copy_large_unboxed_object(lispobj object, int nwords)
            gc_assert(page_table[next_page].write_protected == 0);
 
            old_bytes_used = page_table[next_page].bytes_used;
-           page_table[next_page].allocated = FREE_PAGE;
+           page_table[next_page].allocated = FREE_PAGE_FLAG;
            page_table[next_page].bytes_used = 0;
            bytes_freed += old_bytes_used;
            next_page++;
@@ -1470,8 +1358,8 @@ copy_large_unboxed_object(lispobj object, int nwords)
                   "/copy_large_unboxed bytes_freed=%d\n",
                   bytes_freed));
 
-       generations[from_space].bytes_allocated -= 4*nwords + bytes_freed;
-       generations[new_space].bytes_allocated += 4*nwords;
+       generations[from_space].bytes_allocated -= nwords*N_WORD_BYTES + bytes_freed;
+       generations[new_space].bytes_allocated += nwords*N_WORD_BYTES;
        bytes_allocated -= bytes_freed;
 
        return(object);
@@ -1481,19 +1369,10 @@ copy_large_unboxed_object(lispobj object, int nwords)
        tag = lowtag_of(object);
 
        /* Allocate space. */
-       new = gc_quick_alloc_large_unboxed(nwords*4);
-
-       dest = new;
-       source = (lispobj *) native_pointer(object);
-
-       /* Copy the object. */
-       while (nwords > 0) {
-           dest[0] = source[0];
-           dest[1] = source[1];
-           dest += 2;
-           source += 2;
-           nwords -= 2;
-       }
+       new = gc_quick_alloc_large_unboxed(nwords*N_WORD_BYTES);
+
+        /* Copy the object. */
+        memcpy(new,native_pointer(object),nwords*N_WORD_BYTES);
 
        /* Return Lisp pointer of new object. */
        return ((lispobj) new) | tag;
@@ -1524,7 +1403,7 @@ static lispobj trans_boxed(lispobj object);
 void
 sniff_code_object(struct code *code, unsigned displacement)
 {
-    int nheader_words, ncode_words, nwords;
+    long nheader_words, ncode_words, nwords;
     void *p;
     void *constants_start_addr, *constants_end_addr;
     void *code_start_addr, *code_end_addr;
@@ -1537,10 +1416,10 @@ sniff_code_object(struct code *code, unsigned displacement)
     nheader_words = HeaderValue(*(lispobj *)code);
     nwords = ncode_words + nheader_words;
 
-    constants_start_addr = (void *)code + 5*4;
-    constants_end_addr = (void *)code + nheader_words*4;
-    code_start_addr = (void *)code + nheader_words*4;
-    code_end_addr = (void *)code + nwords*4;
+    constants_start_addr = (void *)code + 5*N_WORD_BYTES;
+    constants_end_addr = (void *)code + nheader_words*N_WORD_BYTES;
+    code_start_addr = (void *)code + nheader_words*N_WORD_BYTES;
+    code_end_addr = (void *)code + nwords*N_WORD_BYTES;
 
     /* Work through the unboxed code. */
     for (p = code_start_addr; p < code_end_addr; p++) {
@@ -1549,7 +1428,7 @@ 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
+#ifdef QSHOW
        unsigned d5 = *((unsigned char *)p - 5);
        unsigned d6 = *((unsigned char *)p - 6);
 #endif
@@ -1694,7 +1573,7 @@ sniff_code_object(struct code *code, unsigned displacement)
 void
 gencgc_apply_code_fixups(struct code *old_code, struct code *new_code)
 {
-    int nheader_words, ncode_words, nwords;
+    long nheader_words, ncode_words, nwords;
     void *constants_start_addr, *constants_end_addr;
     void *code_start_addr, *code_end_addr;
     lispobj fixups = NIL;
@@ -1707,10 +1586,10 @@ gencgc_apply_code_fixups(struct code *old_code, struct code *new_code)
     /* FSHOW((stderr,
             "/compiled code object at %x: header words = %d, code words = %d\n",
             new_code, nheader_words, ncode_words)); */
-    constants_start_addr = (void *)new_code + 5*4;
-    constants_end_addr = (void *)new_code + nheader_words*4;
-    code_start_addr = (void *)new_code + nheader_words*4;
-    code_end_addr = (void *)new_code + nwords*4;
+    constants_start_addr = (void *)new_code + 5*N_WORD_BYTES;
+    constants_end_addr = (void *)new_code + nheader_words*N_WORD_BYTES;
+    code_start_addr = (void *)new_code + nheader_words*N_WORD_BYTES;
+    code_end_addr = (void *)new_code + nwords*N_WORD_BYTES;
     /*
     FSHOW((stderr,
           "/const start = %x, end = %x\n",
@@ -1724,26 +1603,23 @@ gencgc_apply_code_fixups(struct code *old_code, struct code *new_code)
        code objects. Check. */
     fixups = new_code->constants[0];
 
-    /* It will be 0 or the unbound-marker if there are no fixups, and
-     * will be an other pointer if it is valid. */
+    /* It will be 0 or the unbound-marker if there are no fixups (as
+     * will be the case if the code object has been purified, for
+     * example) and will be an other pointer if it is valid. */
     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);
 
-       /*fprintf(stderr,"Fixups for code object not found!?\n");
-         fprintf(stderr,"*** Compiled code object at %x: header_words=%d code_words=%d .\n",
-         new_code, nheader_words, ncode_words);
-         fprintf(stderr,"*** Const. start = %x; end= %x; Code start = %x; end = %x\n",
-         constants_start_addr,constants_end_addr,
-         code_start_addr,code_end_addr);*/
        return;
     }
 
     fixups_vector = (struct vector *)native_pointer(fixups);
 
     /* Could be pointing to a forwarding pointer. */
+    /* FIXME is this always in from_space?  if so, could replace this code with
+     * forwarding_pointer_p/forwarding_pointer_value */
     if (is_lisp_pointer(fixups) &&
        (find_page_index((void*)fixups_vector) != -1) &&
        (fixups_vector->header == 0x01)) {
@@ -1754,12 +1630,11 @@ gencgc_apply_code_fixups(struct code *old_code, struct code *new_code)
 
     /*SHOW("got fixups");*/
 
-    if (widetag_of(fixups_vector->header) ==
-       SIMPLE_ARRAY_UNSIGNED_BYTE_32_WIDETAG) {
+    if (widetag_of(fixups_vector->header) == SIMPLE_ARRAY_WORD_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);
-       int i;
+       long length = fixnum_value(fixups_vector->length);
+       long i;
        for (i = 0; i < length; i++) {
            unsigned offset = fixups_vector->data[i];
            /* Now check the current value of offset. */
@@ -1769,7 +1644,7 @@ gencgc_apply_code_fixups(struct code *old_code, struct code *new_code)
            /* If it's within the old_code object then it must be an
             * absolute fixup (relative ones are not saved) */
            if ((old_value >= (unsigned)old_code)
-               && (old_value < ((unsigned)old_code + nwords*4)))
+               && (old_value < ((unsigned)old_code + nwords*N_WORD_BYTES)))
                /* So add the dispacement. */
                *(unsigned *)((unsigned)code_start_addr + offset) =
                    old_value + displacement;
@@ -1780,6 +1655,8 @@ gencgc_apply_code_fixups(struct code *old_code, struct code *new_code)
                *(unsigned *)((unsigned)code_start_addr + offset) =
                    old_value - displacement;
        }
+    } else {
+        fprintf(stderr, "widetag of fixup vector is %d\n", widetag_of(fixups_vector->header));
     }
 
     /* Check for possible errors. */
@@ -1833,14 +1710,14 @@ int gencgc_hash = 1;
 static int
 scav_vector(lispobj *where, lispobj object)
 {
-    unsigned int kv_length;
+    unsigned long kv_length;
     lispobj *kv_vector;
-    unsigned int length = 0; /* (0 = dummy to stop GCC warning) */
-    lispobj *hash_table;
+    unsigned long length = 0; /* (0 = dummy to stop GCC warning) */
+    struct hash_table *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) */
+    unsigned long *index_vector = NULL; /* (NULL = dummy to stop GCC warning) */
+    unsigned long *next_vector = NULL; /* (NULL = dummy to stop GCC warning) */
+    unsigned long *hash_vector = NULL; /* (NULL = dummy to stop GCC warning) */
     lispobj weak_p_obj;
     unsigned next_vector_length = 0;
 
@@ -1869,8 +1746,10 @@ scav_vector(lispobj *where, lispobj object)
     }
     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);
+    if (widetag_of(hash_table->header) != INSTANCE_HEADER_WIDETAG) {
+       lose("hash table not instance (%x at %x)",
+            hash_table->header,
+            hash_table);
     }
 
     /* Scavenge element 1, which should be some internal symbol that
@@ -1889,26 +1768,26 @@ scav_vector(lispobj *where, lispobj object)
 
     /* Scavenge hash table, which will fix the positions of the other
      * needed objects. */
-    scavenge(hash_table, 16);
+    scavenge(hash_table, sizeof(struct hash_table) / sizeof(lispobj));
 
     /* Cross-check the kv_vector. */
-    if (where != (lispobj *)native_pointer(hash_table[9])) {
-       lose("hash_table table!=this table %x", hash_table[9]);
+    if (where != (lispobj *)native_pointer(hash_table->table)) {
+       lose("hash_table table!=this table %x", hash_table->table);
     }
 
     /* WEAK-P */
-    weak_p_obj = hash_table[10];
+    weak_p_obj = hash_table->weak_p;
 
     /* index vector */
     {
-       lispobj index_vector_obj = hash_table[13];
+       lispobj index_vector_obj = hash_table->index_vector;
 
        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;
+                SIMPLE_ARRAY_WORD_WIDETAG)) {
+           index_vector = ((lispobj *)native_pointer(index_vector_obj)) + 2;
            /*FSHOW((stderr, "/index_vector = %x\n",index_vector));*/
-           length = fixnum_value(((unsigned int *)native_pointer(index_vector_obj))[1]);
+           length = fixnum_value(((lispobj *)native_pointer(index_vector_obj))[1]);
            /*FSHOW((stderr, "/length = %d\n", length));*/
        } else {
            lose("invalid index_vector %x", index_vector_obj);
@@ -1917,14 +1796,14 @@ scav_vector(lispobj *where, lispobj object)
 
     /* next vector */
     {
-       lispobj next_vector_obj = hash_table[14];
+       lispobj next_vector_obj = hash_table->next_vector;
 
        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;
+            SIMPLE_ARRAY_WORD_WIDETAG)) {
+           next_vector = ((lispobj *)native_pointer(next_vector_obj)) + 2;
            /*FSHOW((stderr, "/next_vector = %x\n", next_vector));*/
-           next_vector_length = fixnum_value(((unsigned int *)native_pointer(next_vector_obj))[1]);
+           next_vector_length = fixnum_value(((lispobj *)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);
@@ -1933,18 +1812,14 @@ scav_vector(lispobj *where, lispobj object)
 
     /* maybe hash vector */
     {
-       /* FIXME: This bare "15" offset should become a symbolic
-        * expression of some sort. And all the other bare offsets
-        * too. And the bare "16" in scavenge(hash_table, 16). And
-        * probably other stuff too. Ugh.. */
-       lispobj hash_vector_obj = hash_table[15];
+       lispobj hash_vector_obj = hash_table->hash_vector;
 
        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;
+           (widetag_of(*(lispobj *)native_pointer(hash_vector_obj)) ==
+            SIMPLE_ARRAY_WORD_WIDETAG)){
+           hash_vector = ((lispobj *)native_pointer(hash_vector_obj)) + 2;
            /*FSHOW((stderr, "/hash_vector = %x\n", hash_vector));*/
-           gc_assert(fixnum_value(((unsigned int *)native_pointer(hash_vector_obj))[1])
+           gc_assert(fixnum_value(((lispobj *)native_pointer(hash_vector_obj))[1])
                      == next_vector_length);
        } else {
            hash_vector = NULL;
@@ -1961,10 +1836,15 @@ scav_vector(lispobj *where, lispobj object)
 
     /* Work through the KV vector. */
     {
-       int i;
+       long i;
        for (i = 1; i < next_vector_length; i++) {
            lispobj old_key = kv_vector[2*i];
-           unsigned int  old_index = (old_key & 0x1fffffff)%length;
+
+#if N_WORD_BITS == 32
+           unsigned long old_index = (old_key & 0x1fffffff)%length;
+#elif N_WORD_BITS == 64
+           unsigned long old_index = (old_key & 0x1fffffffffffffff)%length;
+#endif
 
            /* Scavenge the key and value. */
            scavenge(&kv_vector[2*i],2);
@@ -1972,27 +1852,31 @@ scav_vector(lispobj *where, lispobj object)
            /* Check whether the key has moved and is EQ based. */
            {
                lispobj new_key = kv_vector[2*i];
-               unsigned int new_index = (new_key & 0x1fffffff)%length;
+#if N_WORD_BITS == 32
+               unsigned long new_index = (new_key & 0x1fffffff)%length;
+#elif N_WORD_BITS == 64
+               unsigned long new_index = (new_key & 0x1fffffffffffffff)%length;
+#endif
 
                if ((old_index != new_index) &&
                    ((!hash_vector) || (hash_vector[i] == 0x80000000)) &&
                    ((new_key != empty_symbol) ||
                     (kv_vector[2*i] != empty_symbol))) {
 
-                   /*FSHOW((stderr,
-                          "* EQ key %d moved from %x to %x; index %d to %d\n",
-                          i, old_key, new_key, old_index, new_index));*/
+                    /*FSHOW((stderr,
+                           "* EQ key %d moved from %x to %x; index %d to %d\n",
+                           i, old_key, new_key, old_index, new_index));*/
 
                    if (index_vector[old_index] != 0) {
-                       /*FSHOW((stderr, "/P1 %d\n", index_vector[old_index]));*/
+                        /*FSHOW((stderr, "/P1 %d\n", index_vector[old_index]));*/
 
                        /* Unlink the key from the old_index chain. */
                        if (index_vector[old_index] == i) {
                            /*FSHOW((stderr, "/P2a %d\n", next_vector[i]));*/
                            index_vector[old_index] = next_vector[i];
                            /* Link it into the needing rehash chain. */
-                           next_vector[i] = fixnum_value(hash_table[11]);
-                           hash_table[11] = make_fixnum(i);
+                           next_vector[i] = fixnum_value(hash_table->needing_rehash);
+                           hash_table->needing_rehash = make_fixnum(i);
                            /*SHOW("P2");*/
                        } else {
                            unsigned prior = index_vector[old_index];
@@ -2001,15 +1885,15 @@ scav_vector(lispobj *where, lispobj object)
                            /*FSHOW((stderr, "/P3a %d %d\n", prior, next));*/
 
                            while (next != 0) {
-                               /*FSHOW((stderr, "/P3b %d %d\n", prior, next));*/
+                                /*FSHOW((stderr, "/P3b %d %d\n", prior, next));*/
                                if (next == i) {
                                    /* Unlink it. */
                                    next_vector[prior] = next_vector[next];
                                    /* Link it into the needing rehash
                                     * chain. */
                                    next_vector[next] =
-                                       fixnum_value(hash_table[11]);
-                                   hash_table[11] = make_fixnum(next);
+                                       fixnum_value(hash_table->needing_rehash);
+                                   hash_table->needing_rehash = make_fixnum(next);
                                    /*SHOW("/P3");*/
                                    break;
                                }
@@ -2039,7 +1923,7 @@ scav_vector(lispobj *where, lispobj object)
 #define WEAK_POINTER_NWORDS \
     CEILING((sizeof(struct weak_pointer) / sizeof(lispobj)), 2)
 
-static int
+static long
 scav_weak_pointer(lispobj *where, lispobj object)
 {
     struct weak_pointer *wp = weak_pointers;
@@ -2074,79 +1958,53 @@ scav_weak_pointer(lispobj *where, lispobj object)
 }
 
 \f
-/* Scan an area looking for an object which encloses the given pointer.
- * Return the object start on success or NULL on failure. */
-static lispobj *
-search_space(lispobj *start, size_t words, lispobj *pointer)
-{
-    while (words > 0) {
-       size_t count = 1;
-       lispobj thing = *start;
-
-       /* If thing is an immediate then this is a cons. */
-       if (is_lisp_pointer(thing)
-           || ((thing & 3) == 0) /* fixnum */
-           || (widetag_of(thing) == BASE_CHAR_WIDETAG)
-           || (widetag_of(thing) == UNBOUND_MARKER_WIDETAG))
-           count = 2;
-       else
-           count = (sizetab[widetag_of(thing)])(start);
-
-       /* Check whether the pointer is within this object. */
-       if ((pointer >= start) && (pointer < (start+count))) {
-           /* found it! */
-           /*FSHOW((stderr,"/found %x in %x %x\n", pointer, start, thing));*/
-           return(start);
-       }
-
-       /* Round up the count. */
-       count = CEILING(count,2);
-
-       start += count;
-       words -= count;
-    }
-    return (NULL);
-}
-
-static lispobj*
-search_read_only_space(lispobj *pointer)
+lispobj *
+search_read_only_space(void *pointer)
 {
-    lispobj* start = (lispobj*)READ_ONLY_SPACE_START;
-    lispobj* end = (lispobj*)SymbolValue(READ_ONLY_SPACE_FREE_POINTER,0);
-    if ((pointer < start) || (pointer >= end))
+    lispobj *start = (lispobj *) READ_ONLY_SPACE_START;
+    lispobj *end = (lispobj *) SymbolValue(READ_ONLY_SPACE_FREE_POINTER,0);
+    if ((pointer < (void *)start) || (pointer >= (void *)end))
        return NULL;
-    return (search_space(start, (pointer+2)-start, pointer));
+    return (gc_search_space(start,
+                           (((lispobj *)pointer)+2)-start,
+                           (lispobj *) pointer));
 }
 
-static lispobj *
-search_static_space(lispobj *pointer)
+lispobj *
+search_static_space(void *pointer)
 {
-    lispobj* start = (lispobj*)STATIC_SPACE_START;
-    lispobj* end = (lispobj*)SymbolValue(STATIC_SPACE_FREE_POINTER,0);
-    if ((pointer < start) || (pointer >= end))
+    lispobj *start = (lispobj *)STATIC_SPACE_START;
+    lispobj *end = (lispobj *)SymbolValue(STATIC_SPACE_FREE_POINTER,0);
+    if ((pointer < (void *)start) || (pointer >= (void *)end))
        return NULL;
-    return (search_space(start, (pointer+2)-start, pointer));
+    return (gc_search_space(start, 
+                           (((lispobj *)pointer)+2)-start, 
+                           (lispobj *) pointer));
 }
 
 /* a faster version for searching the dynamic space. This will work even
  * if the object is in a current allocation region. */
 lispobj *
-search_dynamic_space(lispobj *pointer)
+search_dynamic_space(void *pointer)
 {
-    int  page_index = find_page_index(pointer);
+    long page_index = find_page_index(pointer);
     lispobj *start;
 
     /* The address may be invalid, so do some checks. */
-    if ((page_index == -1) || (page_table[page_index].allocated == FREE_PAGE))
+    if ((page_index == -1) ||
+       (page_table[page_index].allocated == FREE_PAGE_FLAG))
        return NULL;
     start = (lispobj *)((void *)page_address(page_index)
                        + page_table[page_index].first_object_offset);
-    return (search_space(start, (pointer+2)-start, pointer));
+    return (gc_search_space(start, 
+                           (((lispobj *)pointer)+2)-start, 
+                           (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)
 {
@@ -2173,23 +2031,6 @@ possibly_valid_dynamic_space_pointer(lispobj *pointer)
 
     /* Check that the object pointed to is consistent with the pointer
      * low tag.
-     *
-     * FIXME: It's not safe to rely on the result from this check
-     * before an object is initialized. Thus, if we were interrupted
-     * just as an object had been allocated but not initialized, the
-     * GC relying on this result could bogusly reclaim the memory.
-     * However, we can't really afford to do without this check. So
-     * we should make it safe somehow. 
-     *   (1) Perhaps just review the code to make sure
-     *       that WITHOUT-GCING or WITHOUT-INTERRUPTS or some such
-     *       thing is wrapped around critical sections where allocated
-     *       memory type bits haven't been set.
-     *   (2) Perhaps find some other hack to protect against this, e.g.
-     *       recording the result of the last call to allocate-lisp-memory,
-     *       and returning true from this function when *pointer is
-     *       a reference to that result. 
-     *
-     * (surely pseudo-atomic is supposed to be used for exactly this?)
      */
     switch (lowtag_of((lispobj)pointer)) {
     case FUN_POINTER_LOWTAG:
@@ -2229,12 +2070,18 @@ possibly_valid_dynamic_space_pointer(lispobj *pointer)
        }
        /* Is it plausible cons? */
        if ((is_lisp_pointer(start_addr[0])
-           || ((start_addr[0] & 3) == 0) /* fixnum */
-           || (widetag_of(start_addr[0]) == BASE_CHAR_WIDETAG)
+           || (fixnump(start_addr[0]))
+           || (widetag_of(start_addr[0]) == CHARACTER_WIDETAG)
+#if N_WORD_BITS == 64
+           || (widetag_of(start_addr[0]) == SINGLE_FLOAT_WIDETAG)
+#endif
            || (widetag_of(start_addr[0]) == UNBOUND_MARKER_WIDETAG))
           && (is_lisp_pointer(start_addr[1])
-              || ((start_addr[1] & 3) == 0) /* fixnum */
-              || (widetag_of(start_addr[1]) == BASE_CHAR_WIDETAG)
+              || (fixnump(start_addr[1]))
+              || (widetag_of(start_addr[1]) == CHARACTER_WIDETAG)
+#if N_WORD_BITS == 64
+              || (widetag_of(start_addr[1]) == SINGLE_FLOAT_WIDETAG)
+#endif
               || (widetag_of(start_addr[1]) == UNBOUND_MARKER_WIDETAG)))
            break;
        else {
@@ -2280,7 +2127,10 @@ possibly_valid_dynamic_space_pointer(lispobj *pointer)
        }
        switch (widetag_of(start_addr[0])) {
        case UNBOUND_MARKER_WIDETAG:
-       case BASE_CHAR_WIDETAG:
+       case CHARACTER_WIDETAG:
+#if N_WORD_BITS == 64
+       case SINGLE_FLOAT_WIDETAG:
+#endif
            if (gencgc_verbose)
                FSHOW((stderr,
                       "*Wo3: %x %x %x\n",
@@ -2317,7 +2167,11 @@ possibly_valid_dynamic_space_pointer(lispobj *pointer)
        case COMPLEX_LONG_FLOAT_WIDETAG:
 #endif
        case SIMPLE_ARRAY_WIDETAG:
-       case COMPLEX_STRING_WIDETAG:
+       case COMPLEX_BASE_STRING_WIDETAG:
+#ifdef COMPLEX_CHARACTER_STRING_WIDETAG
+       case COMPLEX_CHARACTER_STRING_WIDETAG:
+#endif
+       case COMPLEX_VECTOR_NIL_WIDETAG:
        case COMPLEX_BIT_VECTOR_WIDETAG:
        case COMPLEX_VECTOR_WIDETAG:
        case COMPLEX_ARRAY_WIDETAG:
@@ -2326,19 +2180,39 @@ possibly_valid_dynamic_space_pointer(lispobj *pointer)
        case FDEFN_WIDETAG:
        case CODE_HEADER_WIDETAG:
        case BIGNUM_WIDETAG:
+#if N_WORD_BITS != 64
        case SINGLE_FLOAT_WIDETAG:
+#endif
        case DOUBLE_FLOAT_WIDETAG:
 #ifdef LONG_FLOAT_WIDETAG
        case LONG_FLOAT_WIDETAG:
 #endif
-       case SIMPLE_STRING_WIDETAG:
+       case SIMPLE_BASE_STRING_WIDETAG:
+#ifdef SIMPLE_CHARACTER_STRING_WIDETAG
+       case SIMPLE_CHARACTER_STRING_WIDETAG:
+#endif
        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:
+#ifdef  SIMPLE_ARRAY_UNSIGNED_BYTE_29_WIDETAG
+       case SIMPLE_ARRAY_UNSIGNED_BYTE_29_WIDETAG:
+#endif
+       case SIMPLE_ARRAY_UNSIGNED_BYTE_31_WIDETAG:
        case SIMPLE_ARRAY_UNSIGNED_BYTE_32_WIDETAG:
+#ifdef  SIMPLE_ARRAY_UNSIGNED_BYTE_60_WIDETAG
+       case SIMPLE_ARRAY_UNSIGNED_BYTE_60_WIDETAG:
+#endif
+#ifdef  SIMPLE_ARRAY_UNSIGNED_BYTE_63_WIDETAG
+       case SIMPLE_ARRAY_UNSIGNED_BYTE_63_WIDETAG:
+#endif
+#ifdef  SIMPLE_ARRAY_UNSIGNED_BYTE_64_WIDETAG
+       case SIMPLE_ARRAY_UNSIGNED_BYTE_64_WIDETAG:
+#endif
 #ifdef SIMPLE_ARRAY_SIGNED_BYTE_8_WIDETAG
        case SIMPLE_ARRAY_SIGNED_BYTE_8_WIDETAG:
 #endif
@@ -2351,6 +2225,12 @@ possibly_valid_dynamic_space_pointer(lispobj *pointer)
 #ifdef SIMPLE_ARRAY_SIGNED_BYTE_32_WIDETAG
        case SIMPLE_ARRAY_SIGNED_BYTE_32_WIDETAG:
 #endif
+#ifdef SIMPLE_ARRAY_SIGNED_BYTE_61_WIDETAG
+       case SIMPLE_ARRAY_SIGNED_BYTE_61_WIDETAG:
+#endif
+#ifdef SIMPLE_ARRAY_SIGNED_BYTE_64_WIDETAG
+       case SIMPLE_ARRAY_SIGNED_BYTE_64_WIDETAG:
+#endif
        case SIMPLE_ARRAY_SINGLE_FLOAT_WIDETAG:
        case SIMPLE_ARRAY_DOUBLE_FLOAT_WIDETAG:
 #ifdef SIMPLE_ARRAY_LONG_FLOAT_WIDETAG
@@ -2399,30 +2279,48 @@ possibly_valid_dynamic_space_pointer(lispobj *pointer)
 static void
 maybe_adjust_large_object(lispobj *where)
 {
-    int first_page;
-    int nwords;
+    long first_page;
+    long nwords;
 
-    int remaining_bytes;
-    int next_page;
-    int bytes_freed;
-    int old_bytes_used;
+    long remaining_bytes;
+    long next_page;
+    long bytes_freed;
+    long old_bytes_used;
 
     int boxed;
 
     /* Check whether it's a vector or bignum object. */
     switch (widetag_of(where[0])) {
     case SIMPLE_VECTOR_WIDETAG:
-       boxed = BOXED_PAGE;
+       boxed = BOXED_PAGE_FLAG;
        break;
     case BIGNUM_WIDETAG:
-    case SIMPLE_STRING_WIDETAG:
+    case SIMPLE_BASE_STRING_WIDETAG:
+#ifdef SIMPLE_CHARACTER_STRING_WIDETAG
+    case SIMPLE_CHARACTER_STRING_WIDETAG:
+#endif
     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:
+#ifdef  SIMPLE_ARRAY_UNSIGNED_BYTE_29_WIDETAG
+    case SIMPLE_ARRAY_UNSIGNED_BYTE_29_WIDETAG:
+#endif
+    case SIMPLE_ARRAY_UNSIGNED_BYTE_31_WIDETAG:
     case SIMPLE_ARRAY_UNSIGNED_BYTE_32_WIDETAG:
+#ifdef SIMPLE_ARRAY_UNSIGNED_BYTE_60_WIDETAG
+    case SIMPLE_ARRAY_UNSIGNED_BYTE_60_WIDETAG:
+#endif
+#ifdef SIMPLE_ARRAY_UNSIGNED_BYTE_63_WIDETAG
+    case SIMPLE_ARRAY_UNSIGNED_BYTE_63_WIDETAG:
+#endif
+#ifdef SIMPLE_ARRAY_UNSIGNED_BYTE_64_WIDETAG
+    case SIMPLE_ARRAY_UNSIGNED_BYTE_64_WIDETAG:
+#endif
 #ifdef SIMPLE_ARRAY_SIGNED_BYTE_8_WIDETAG
     case SIMPLE_ARRAY_SIGNED_BYTE_8_WIDETAG:
 #endif
@@ -2435,6 +2333,12 @@ maybe_adjust_large_object(lispobj *where)
 #ifdef SIMPLE_ARRAY_SIGNED_BYTE_32_WIDETAG
     case SIMPLE_ARRAY_SIGNED_BYTE_32_WIDETAG:
 #endif
+#ifdef SIMPLE_ARRAY_SIGNED_BYTE_61_WIDETAG
+    case SIMPLE_ARRAY_SIGNED_BYTE_61_WIDETAG:
+#endif
+#ifdef SIMPLE_ARRAY_SIGNED_BYTE_64_WIDETAG
+    case SIMPLE_ARRAY_SIGNED_BYTE_64_WIDETAG:
+#endif
     case SIMPLE_ARRAY_SINGLE_FLOAT_WIDETAG:
     case SIMPLE_ARRAY_DOUBLE_FLOAT_WIDETAG:
 #ifdef SIMPLE_ARRAY_LONG_FLOAT_WIDETAG
@@ -2449,7 +2353,7 @@ maybe_adjust_large_object(lispobj *where)
 #ifdef SIMPLE_ARRAY_COMPLEX_LONG_FLOAT_WIDETAG
     case SIMPLE_ARRAY_COMPLEX_LONG_FLOAT_WIDETAG:
 #endif
-       boxed = UNBOXED_PAGE;
+       boxed = UNBOXED_PAGE_FLAG;
        break;
     default:
        return;
@@ -2470,22 +2374,22 @@ maybe_adjust_large_object(lispobj *where)
     gc_assert(page_table[first_page].first_object_offset == 0);
 
     next_page = first_page;
-    remaining_bytes = nwords*4;
-    while (remaining_bytes > 4096) {
+    remaining_bytes = nwords*N_WORD_BYTES;
+    while (remaining_bytes > PAGE_BYTES) {
        gc_assert(page_table[next_page].gen == from_space);
-       gc_assert((page_table[next_page].allocated == BOXED_PAGE)
-                 || (page_table[next_page].allocated == UNBOXED_PAGE));
+       gc_assert((page_table[next_page].allocated == BOXED_PAGE_FLAG)
+                 || (page_table[next_page].allocated == UNBOXED_PAGE_FLAG));
        gc_assert(page_table[next_page].large_object);
        gc_assert(page_table[next_page].first_object_offset ==
-                 -4096*(next_page-first_page));
-       gc_assert(page_table[next_page].bytes_used == 4096);
+                 -PAGE_BYTES*(next_page-first_page));
+       gc_assert(page_table[next_page].bytes_used == PAGE_BYTES);
 
        page_table[next_page].allocated = boxed;
 
        /* Shouldn't be write-protected at this stage. Essential that the
         * pages aren't. */
        gc_assert(!page_table[next_page].write_protected);
-       remaining_bytes -= 4096;
+       remaining_bytes -= PAGE_BYTES;
        next_page++;
     }
 
@@ -2507,13 +2411,13 @@ maybe_adjust_large_object(lispobj *where)
 
     /* Free any remaining pages; needs care. */
     next_page++;
-    while ((old_bytes_used == 4096) &&
+    while ((old_bytes_used == PAGE_BYTES) &&
           (page_table[next_page].gen == from_space) &&
-          ((page_table[next_page].allocated == UNBOXED_PAGE)
-           || (page_table[next_page].allocated == BOXED_PAGE)) &&
+          ((page_table[next_page].allocated == UNBOXED_PAGE_FLAG)
+           || (page_table[next_page].allocated == BOXED_PAGE_FLAG)) &&
           page_table[next_page].large_object &&
           (page_table[next_page].first_object_offset ==
-           -(next_page - first_page)*4096)) {
+           -(next_page - first_page)*PAGE_BYTES)) {
        /* It checks out OK, free the page. We don't need to both zeroing
         * pages as this should have been done before shrinking the
         * object. These pages shouldn't be write protected as they
@@ -2521,7 +2425,7 @@ maybe_adjust_large_object(lispobj *where)
        gc_assert(page_table[next_page].write_protected == 0);
 
        old_bytes_used = page_table[next_page].bytes_used;
-       page_table[next_page].allocated = FREE_PAGE;
+       page_table[next_page].allocated = FREE_PAGE_FLAG;
        page_table[next_page].bytes_used = 0;
        bytes_freed += old_bytes_used;
        next_page++;
@@ -2543,11 +2447,8 @@ maybe_adjust_large_object(lispobj *where)
  * page_table so that it will not be relocated during a GC.
  *
  * 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.
- *
- * This ensures that objects spanning pages are not broken.
+ * the start of its region, then marking all pages dont_move from there
+ * up to the first page that's not full or has a different generation
  *
  * It is assumed that all the page static flags have been cleared at
  * the start of a GC.
@@ -2557,59 +2458,60 @@ maybe_adjust_large_object(lispobj *where)
 static void
 preserve_pointer(void *addr)
 {
-    int addr_page_index = find_page_index(addr);
-    int first_page;
-    int i;
+    long addr_page_index = find_page_index(addr);
+    long first_page;
+    long i;
     unsigned region_allocation;
 
     /* quick check 1: Address is quite likely to have been invalid. */
     if ((addr_page_index == -1)
-       || (page_table[addr_page_index].allocated == FREE_PAGE)
+       || (page_table[addr_page_index].allocated == FREE_PAGE_FLAG)
        || (page_table[addr_page_index].bytes_used == 0)
        || (page_table[addr_page_index].gen != from_space)
        /* 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));
+    gc_assert(!(page_table[addr_page_index].allocated&OPEN_REGION_PAGE_FLAG));
     /* (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;
 
     /* quick check 2: Check the offset within the page.
      *
-     * FIXME: The mask should have a symbolic name, and ideally should
-     * be derived from page size instead of hardwired to 0xfff.
-     * (Also fix other uses of 0xfff, elsewhere.) */
-    if (((unsigned)addr & 0xfff) > page_table[addr_page_index].bytes_used)
+     */
+    if (((unsigned)addr & (PAGE_BYTES - 1)) > page_table[addr_page_index].bytes_used)
        return;
 
     /* Filter out anything which can't be a pointer to a Lisp object
      * (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 (!(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. */
-
-    /* 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.
-     */
+    /* Find the beginning of the region.  Note that there may be
+     * objects in the region preceding the one that we were passed a
+     * pointer to: if this is the case, we will write-protect all the
+     * previous objects' pages too.     */
 
+#if 0
+    /* I think this'd work just as well, but without the assertions.
+     * -dan 2004.01.01 */
+    first_page=
+       find_page_index(page_address(addr_page_index)+
+                       page_table[addr_page_index].first_object_offset);
+#else 
+    first_page = addr_page_index;
     while (page_table[first_page].first_object_offset != 0) {
        --first_page;
        /* Do some checks. */
-       gc_assert(page_table[first_page].bytes_used == 4096);
+       gc_assert(page_table[first_page].bytes_used == PAGE_BYTES);
        gc_assert(page_table[first_page].gen == from_space);
        gc_assert(page_table[first_page].allocated == region_allocation);
     }
+#endif
 
     /* Adjust any large objects before promotion as they won't be
      * copied after promotion. */
@@ -2619,10 +2521,10 @@ preserve_pointer(void *addr)
         * 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)
+       if ((page_table[addr_page_index].allocated == FREE_PAGE_FLAG)
            || (page_table[addr_page_index].bytes_used == 0)
            /* Check the offset within the page. */
-           || (((unsigned)addr & 0xfff)
+           || (((unsigned)addr & (PAGE_BYTES - 1))
                > page_table[addr_page_index].bytes_used)) {
            FSHOW((stderr,
                   "weird? ignore ptr 0x%x to freed area of large object\n",
@@ -2656,9 +2558,9 @@ preserve_pointer(void *addr)
        gc_assert(!page_table[i].write_protected);
 
        /* Check whether this is the last page in this contiguous block.. */
-       if ((page_table[i].bytes_used < 4096)
-           /* ..or it is 4096 and is the last in the block */
-           || (page_table[i+1].allocated == FREE_PAGE)
+       if ((page_table[i].bytes_used < PAGE_BYTES)
+           /* ..or it is PAGE_BYTES and is the last in the block */
+           || (page_table[i+1].allocated == FREE_PAGE_FLAG)
            || (page_table[i+1].bytes_used == 0) /* next page free */
            || (page_table[i+1].gen != from_space) /* diff. gen */
            || (page_table[i+1].first_object_offset == 0))
@@ -2683,21 +2585,22 @@ preserve_pointer(void *addr)
  *
  * We return 1 if the page was write-protected, else 0. */
 static int
-update_page_write_prot(int page)
+update_page_write_prot(long page)
 {
     int gen = page_table[page].gen;
-    int j;
+    long j;
     int wp_it = 1;
     void **page_addr = (void **)page_address(page);
-    int num_words = page_table[page].bytes_used / 4;
+    long num_words = page_table[page].bytes_used / N_WORD_BYTES;
 
     /* Shouldn't be a free page. */
-    gc_assert(page_table[page].allocated != FREE_PAGE);
+    gc_assert(page_table[page].allocated != FREE_PAGE_FLAG);
     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_FLAG))
        return (0);
 
     /* Scan the page for pointers to younger generations or the
@@ -2705,12 +2608,12 @@ update_page_write_prot(int page)
 
     for (j = 0; j < num_words; j++) {
        void *ptr = *(page_addr+j);
-       int index = find_page_index(ptr);
+       long index = find_page_index(ptr);
 
        /* Check that it's in the dynamic space */
        if (index != -1)
            if (/* Does it point to a younger or the temp. generation? */
-               ((page_table[index].allocated != FREE_PAGE)
+               ((page_table[index].allocated != FREE_PAGE_FLAG)
                 && (page_table[index].bytes_used != 0)
                 && ((page_table[index].gen < gen)
                     || (page_table[index].gen == NUM_GENERATIONS)))
@@ -2730,7 +2633,7 @@ update_page_write_prot(int page)
        /*FSHOW((stderr, "/write-protecting page %d gen %d\n", page, gen));*/
 
        os_protect((void *)page_addr,
-                  4096,
+                  PAGE_BYTES,
                   OS_VM_PROT_READ|OS_VM_PROT_EXECUTE);
 
        /* Note the page as protected in the page tables. */
@@ -2743,7 +2646,7 @@ update_page_write_prot(int page)
 /* Scavenge a generation.
  *
  * This will not resolve all pointers when generation is the new
- * space, as new objects may be added which are not check here - use
+ * space, as new objects may be added which are not checked here - use
  * scavenge_newspace generation.
  *
  * Write-protected pages should not have any pointers to the
@@ -2774,7 +2677,7 @@ update_page_write_prot(int page)
 static void
 scavenge_generation(int generation)
 {
-    int i;
+    long i;
     int num_wp = 0;
 
 #define SC_GEN_CK 0
@@ -2785,61 +2688,43 @@ 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_FLAG)
            && (page_table[i].bytes_used != 0)
            && (page_table[i].gen == generation)) {
-           int last_page;
+           long last_page,j;
+           int write_protected=1;
 
-           /* This should be the start of a contiguous block. */
+           /* This should be the start of a region */
            gc_assert(page_table[i].first_object_offset == 0);
 
-           /* We need to find the full extent of this contiguous
-            * block in case objects span pages. */
-
-           /* 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++)
-               /* 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))
+           /* Now work forward until the end of the region */
+           for (last_page = i; ; last_page++) {
+               write_protected =
+                   write_protected && page_table[last_page].write_protected;
+               if ((page_table[last_page].bytes_used < PAGE_BYTES)
+                   /* Or it is PAGE_BYTES and is the last in the block */
+                   || (!(page_table[last_page+1].allocated & BOXED_PAGE_FLAG))
                    || (page_table[last_page+1].bytes_used == 0)
                    || (page_table[last_page+1].gen != generation)
                    || (page_table[last_page+1].first_object_offset == 0))
                    break;
-
-           /* Do a limited check for write_protected pages. If all pages
-            * are write_protected then there is no need to scavenge. */
-           {
-               int j, all_wp = 1;
-               for (j = i; j <= last_page; j++)
-                   if (page_table[j].write_protected == 0) {
-                       all_wp = 0;
-                       break;
-                   }
-#if !SC_GEN_CK
-               if (all_wp == 0)
-#endif
-                   {
-                       scavenge(page_address(i), (page_table[last_page].bytes_used
-                                                  + (last_page-i)*4096)/4);
-
-                       /* Now scan the pages and write protect those
-                        * that don't have pointers to younger
-                        * generations. */
-                       if (enable_page_protection) {
-                           for (j = i; j <= last_page; j++) {
-                               num_wp += update_page_write_prot(j);
-                           }
-                       }
+           }
+           if (!write_protected) {
+               scavenge(page_address(i), 
+                        (page_table[last_page].bytes_used +
+                         (last_page-i)*PAGE_BYTES)/N_WORD_BYTES);
+               
+               /* Now scan the pages and write protect those that
+                * don't have pointers to younger generations. */
+               if (enable_page_protection) {
+                   for (j = i; j <= last_page; j++) {
+                       num_wp += update_page_write_prot(j);
                    }
+               }
            }
            i = last_page;
        }
     }
-
     if ((gencgc_verbose > 1) && (num_wp != 0)) {
        FSHOW((stderr,
               "/write protected %d pages within generation %d\n",
@@ -2850,7 +2735,7 @@ scavenge_generation(int generation)
     /* Check that none of the write_protected pages in this generation
      * have been written to. */
     for (i = 0; i < NUM_PAGES; i++) {
-       if ((page_table[i].allocation ! =FREE_PAGE)
+       if ((page_table[i].allocation != FREE_PAGE_FLAG)
            && (page_table[i].bytes_used != 0)
            && (page_table[i].gen == generation)
            && (page_table[i].write_protected_cleared != 0)) {
@@ -2897,21 +2782,22 @@ static struct new_area new_areas_2[NUM_NEW_AREAS];
 static void
 scavenge_newspace_generation_one_scan(int generation)
 {
-    int i;
+    long i;
 
     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)
+       /* Note that this skips over open regions when it encounters them. */
+       if ((page_table[i].allocated & BOXED_PAGE_FLAG)
            && (page_table[i].bytes_used != 0)
            && (page_table[i].gen == generation)
            && ((page_table[i].write_protected == 0)
                /* (This may be redundant as write_protected is now
                 * cleared before promotion.) */
                || (page_table[i].dont_move == 1))) {
-           int last_page;
+           long last_page;
+           int all_wp=1;
 
            /* The scavenge will start at the first_object_offset of page i.
             *
@@ -2922,52 +2808,36 @@ scavenge_newspace_generation_one_scan(int generation)
             * 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++) {
+               /* If all pages are write-protected and movable, 
+                * then no need to scavenge */
+               all_wp=all_wp && page_table[last_page].write_protected && 
+                   !page_table[last_page].dont_move;
+               
                /* 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))
+               if ((page_table[last_page].bytes_used < PAGE_BYTES)
+                   /* Or it is PAGE_BYTES and is the last in the block */
+                   || (!(page_table[last_page+1].allocated & BOXED_PAGE_FLAG))
                    || (page_table[last_page+1].bytes_used == 0)
                    || (page_table[last_page+1].gen != generation)
                    || (page_table[last_page+1].first_object_offset == 0))
                    break;
            }
 
-           /* Do a limited check for write-protected pages. If all
-            * pages are write-protected then no need to scavenge,
-            * except if the pages are marked dont_move. */
-           {
-               int j, all_wp = 1;
-               for (j = i; j <= last_page; j++)
-                   if ((page_table[j].write_protected == 0)
-                       || (page_table[j].dont_move != 0)) {
-                       all_wp = 0;
-                       break;
-                   }
-
-               if (!all_wp) {
-                   int size;
-
-                   /* Calculate the size. */
-                   if (last_page == i)
-                       size = (page_table[last_page].bytes_used
-                               - page_table[i].first_object_offset)/4;
-                   else
-                       size = (page_table[last_page].bytes_used
-                               + (last_page-i)*4096
-                               - page_table[i].first_object_offset)/4;
-                   
-                   {
-                       new_areas_ignore_page = last_page;
-                       
-                       scavenge(page_address(i) +
-                                page_table[i].first_object_offset,
-                                size);
-
-                   }
-               }
+           /* Do a limited check for write-protected pages.  */
+           if (!all_wp) {
+               long size;
+               
+               size = (page_table[last_page].bytes_used
+                       + (last_page-i)*PAGE_BYTES
+                       - page_table[i].first_object_offset)/N_WORD_BYTES;
+               new_areas_ignore_page = last_page;
+               
+               scavenge(page_address(i) +
+                        page_table[i].first_object_offset,
+                        size);
+               
            }
-
            i = last_page;
        }
     }
@@ -2980,15 +2850,15 @@ scavenge_newspace_generation_one_scan(int generation)
 static void
 scavenge_newspace_generation(int generation)
 {
-    int i;
+    long i;
 
     /* 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;
+    long current_new_areas_index;
 
-    /* the new_areas created but the previous scavenge cycle */
+    /* the new_areas created by the previous scavenge cycle */
     struct new_area (*previous_new_areas)[] = NULL;
-    int previous_new_areas_index;
+    long previous_new_areas_index;
 
     /* Flush the current regions updating the tables. */
     gc_alloc_update_all_page_tables();
@@ -3061,12 +2931,10 @@ scavenge_newspace_generation(int generation)
 
            /* Work through previous_new_areas. */
            for (i = 0; i < previous_new_areas_index; i++) {
-               /* FIXME: All these bare *4 and /4 should be something
-                * like BYTES_PER_WORD or WBYTES. */
-               int page = (*previous_new_areas)[i].page;
-               int offset = (*previous_new_areas)[i].offset;
-               int size = (*previous_new_areas)[i].size / 4;
-               gc_assert((*previous_new_areas)[i].size % 4 == 0);
+               long page = (*previous_new_areas)[i].page;
+               long offset = (*previous_new_areas)[i].offset;
+               long size = (*previous_new_areas)[i].size / N_WORD_BYTES;
+               gc_assert((*previous_new_areas)[i].size % N_WORD_BYTES == 0);
                scavenge(page_address(page)+offset, size);
            }
 
@@ -3088,7 +2956,7 @@ scavenge_newspace_generation(int generation)
     /* Check that none of the write_protected pages in this generation
      * have been written to. */
     for (i = 0; i < NUM_PAGES; i++) {
-       if ((page_table[i].allocation != FREE_PAGE)
+       if ((page_table[i].allocation != FREE_PAGE_FLAG)
            && (page_table[i].bytes_used != 0)
            && (page_table[i].gen == generation)
            && (page_table[i].write_protected_cleared != 0)
@@ -3108,10 +2976,10 @@ scavenge_newspace_generation(int generation)
 static void
 unprotect_oldspace(void)
 {
-    int i;
+    long i;
 
     for (i = 0; i < last_free_page; i++) {
-       if ((page_table[i].allocated != FREE_PAGE)
+       if ((page_table[i].allocated != FREE_PAGE_FLAG)
            && (page_table[i].bytes_used != 0)
            && (page_table[i].gen == from_space)) {
            void *page_start;
@@ -3121,7 +2989,7 @@ unprotect_oldspace(void)
            /* Remove any write-protection. We should be able to rely
             * on the write-protect flag to avoid redundant calls. */
            if (page_table[i].write_protected) {
-               os_protect(page_start, 4096, OS_VM_PROT_ALL);
+               os_protect(page_start, PAGE_BYTES, OS_VM_PROT_ALL);
                page_table[i].write_protected = 0;
            }
        }
@@ -3132,19 +3000,18 @@ unprotect_oldspace(void)
  * assumes that all objects have been copied or promoted to an older
  * generation. Bytes_allocated and the generation bytes_allocated
  * counter are updated. The number of bytes freed is returned. */
-extern void i586_bzero(void *addr, int nbytes);
-static int
+static long
 free_oldspace(void)
 {
-    int bytes_freed = 0;
-    int first_page, last_page;
+    long bytes_freed = 0;
+    long first_page, last_page;
 
     first_page = 0;
 
     do {
        /* Find a first page for the next region of pages. */
        while ((first_page < last_free_page)
-              && ((page_table[first_page].allocated == FREE_PAGE)
+              && ((page_table[first_page].allocated == FREE_PAGE_FLAG)
                   || (page_table[first_page].bytes_used == 0)
                   || (page_table[first_page].gen != from_space)))
            first_page++;
@@ -3160,7 +3027,7 @@ free_oldspace(void)
            bytes_freed += page_table[last_page].bytes_used;
            generations[page_table[last_page].gen].bytes_allocated -=
                page_table[last_page].bytes_used;
-           page_table[last_page].allocated = FREE_PAGE;
+           page_table[last_page].allocated = FREE_PAGE_FLAG;
            page_table[last_page].bytes_used = 0;
 
            /* Remove any write-protection. We should be able to rely
@@ -3169,14 +3036,14 @@ free_oldspace(void)
                void  *page_start = (void *)page_address(last_page);
        
                if (page_table[last_page].write_protected) {
-                   os_protect(page_start, 4096, OS_VM_PROT_ALL);
+                   os_protect(page_start, PAGE_BYTES, OS_VM_PROT_ALL);
                    page_table[last_page].write_protected = 0;
                }
            }
            last_page++;
        }
        while ((last_page < last_free_page)
-              && (page_table[last_page].allocated != FREE_PAGE)
+              && (page_table[last_page].allocated != FREE_PAGE_FLAG)
               && (page_table[last_page].bytes_used != 0)
               && (page_table[last_page].gen == from_space));
 
@@ -3190,26 +3057,17 @@ free_oldspace(void)
 
            page_start = (void *)page_address(first_page);
 
-           os_invalidate(page_start, 4096*(last_page-first_page));
-           addr = os_validate(page_start, 4096*(last_page-first_page));
+           os_invalidate(page_start, PAGE_BYTES*(last_page-first_page));
+           addr = os_validate(page_start, PAGE_BYTES*(last_page-first_page));
            if (addr == NULL || addr != page_start) {
-               /* Is this an error condition? I couldn't really tell from
-                * the old CMU CL code, which fprintf'ed a message with
-                * an exclamation point at the end. But I've never seen the
-                * message, so it must at least be unusual..
-                *
-                * (The same condition is also tested for in gc_free_heap.)
-                *
-                * -- WHN 19991129 */
-               lose("i586_bzero: page moved, 0x%08x ==> 0x%08x",
-                    page_start,
+               lose("free_oldspace: page moved, 0x%08x ==> 0x%08x",page_start,
                     addr);
            }
        } else {
-           int *page_start;
+           long *page_start;
 
-           page_start = (int *)page_address(first_page);
-           i586_bzero(page_start, 4096*(last_page-first_page));
+           page_start = (long *)page_address(first_page);
+           memset(page_start, 0,PAGE_BYTES*(last_page-first_page));
        }
 
        first_page = last_page;
@@ -3226,11 +3084,11 @@ static void
 print_ptr(lispobj *addr)
 {
     /* If addr is in the dynamic space then out the page information. */
-    int pi1 = find_page_index((void*)addr);
+    long pi1 = find_page_index((void*)addr);
 
     if (pi1 != -1)
        fprintf(stderr,"  %x: page %d  alloc %d  gen %d  bytes_used %d  offset %d  dont_move %d\n",
-               (unsigned int) addr,
+               (unsigned long) addr,
                pi1,
                page_table[pi1].allocated,
                page_table[pi1].gen,
@@ -3250,7 +3108,7 @@ print_ptr(lispobj *addr)
 }
 #endif
 
-extern int undefined_tramp;
+extern long undefined_tramp;
 
 static void
 verify_space(lispobj *start, size_t words)
@@ -3265,11 +3123,11 @@ verify_space(lispobj *start, size_t words)
        lispobj thing = *(lispobj*)start;
 
        if (is_lisp_pointer(thing)) {
-           int page_index = find_page_index((void*)thing);
-           int to_readonly_space =
+           long page_index = find_page_index((void*)thing);
+           long to_readonly_space =
                (READ_ONLY_SPACE_START <= thing &&
                 thing < SymbolValue(READ_ONLY_SPACE_FREE_POINTER,0));
-           int to_static_space =
+           long to_static_space =
                (STATIC_SPACE_START <= thing &&
                 thing < SymbolValue(STATIC_SPACE_FREE_POINTER,0));
 
@@ -3277,7 +3135,7 @@ verify_space(lispobj *start, size_t words)
            if (page_index != -1) {
                /* If it's within the dynamic space it should point to a used
                 * page. XX Could check the offset too. */
-               if ((page_table[page_index].allocated != FREE_PAGE)
+               if ((page_table[page_index].allocated != FREE_PAGE_FLAG)
                    && (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! */
@@ -3312,9 +3170,8 @@ verify_space(lispobj *start, size_t words)
                }
            }
        } else {
-           if (thing & 0x3) { /* Skip fixnums. FIXME: There should be an
-                               * is_fixnum for this. */
-
+           if (!(fixnump(thing))) { 
+               /* skip fixnums */
                switch(widetag_of(*start)) {
 
                    /* boxed objects */
@@ -3322,7 +3179,11 @@ verify_space(lispobj *start, size_t words)
                case RATIO_WIDETAG:
                case COMPLEX_WIDETAG:
                case SIMPLE_ARRAY_WIDETAG:
-               case COMPLEX_STRING_WIDETAG:
+               case COMPLEX_BASE_STRING_WIDETAG:
+#ifdef COMPLEX_CHARACTER_STRING_WIDETAG
+               case COMPLEX_CHARACTER_STRING_WIDETAG:
+#endif
+               case COMPLEX_VECTOR_NIL_WIDETAG:
                case COMPLEX_BIT_VECTOR_WIDETAG:
                case COMPLEX_VECTOR_WIDETAG:
                case COMPLEX_ARRAY_WIDETAG:
@@ -3330,7 +3191,10 @@ verify_space(lispobj *start, size_t words)
                case FUNCALLABLE_INSTANCE_HEADER_WIDETAG:
                case VALUE_CELL_HEADER_WIDETAG:
                case SYMBOL_HEADER_WIDETAG:
-               case BASE_CHAR_WIDETAG:
+               case CHARACTER_WIDETAG:
+#if N_WORD_BITS == 64
+               case SINGLE_FLOAT_WIDETAG:
+#endif
                case UNBOUND_MARKER_WIDETAG:
                case INSTANCE_HEADER_WIDETAG:
                case FDEFN_WIDETAG:
@@ -3341,7 +3205,7 @@ verify_space(lispobj *start, size_t words)
                    {
                        lispobj object = *start;
                        struct code *code;
-                       int nheader_words, ncode_words, nwords;
+                       long nheader_words, ncode_words, nwords;
                        lispobj fheaderl;
                        struct simple_fun *fheaderp;
 
@@ -3360,7 +3224,7 @@ verify_space(lispobj *start, size_t words)
                             * 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)
+                           && fixnump(code->trace_table_offset)
                            /* Only when enabled */
                            && verify_dynamic_code_check) {
                            FSHOW((stderr,
@@ -3393,7 +3257,9 @@ verify_space(lispobj *start, size_t words)
        
                    /* unboxed objects */
                case BIGNUM_WIDETAG:
+#if N_WORD_BITS != 64
                case SINGLE_FLOAT_WIDETAG:
+#endif
                case DOUBLE_FLOAT_WIDETAG:
 #ifdef COMPLEX_LONG_FLOAT_WIDETAG
                case LONG_FLOAT_WIDETAG:
@@ -3407,14 +3273,32 @@ verify_space(lispobj *start, size_t words)
 #ifdef COMPLEX_LONG_FLOAT_WIDETAG
                case COMPLEX_LONG_FLOAT_WIDETAG:
 #endif
-               case SIMPLE_STRING_WIDETAG:
+               case SIMPLE_BASE_STRING_WIDETAG:
+#ifdef SIMPLE_CHARACTER_STRING_WIDETAG
+               case SIMPLE_CHARACTER_STRING_WIDETAG:
+#endif
                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:
+#ifdef SIMPLE_ARRAY_UNSIGNED_BYTE_29_WIDETAG
+               case SIMPLE_ARRAY_UNSIGNED_BYTE_29_WIDETAG:
+#endif
+               case SIMPLE_ARRAY_UNSIGNED_BYTE_31_WIDETAG:
                case SIMPLE_ARRAY_UNSIGNED_BYTE_32_WIDETAG:
+#ifdef SIMPLE_ARRAY_UNSIGNED_BYTE_60_WIDETAG
+               case SIMPLE_ARRAY_UNSIGNED_BYTE_60_WIDETAG:
+#endif
+#ifdef SIMPLE_ARRAY_UNSIGNED_BYTE_63_WIDETAG
+               case SIMPLE_ARRAY_UNSIGNED_BYTE_63_WIDETAG:
+#endif
+#ifdef SIMPLE_ARRAY_UNSIGNED_BYTE_64_WIDETAG
+               case SIMPLE_ARRAY_UNSIGNED_BYTE_64_WIDETAG:
+#endif
 #ifdef SIMPLE_ARRAY_SIGNED_BYTE_8_WIDETAG
                case SIMPLE_ARRAY_SIGNED_BYTE_8_WIDETAG:
 #endif
@@ -3427,6 +3311,12 @@ verify_space(lispobj *start, size_t words)
 #ifdef SIMPLE_ARRAY_SIGNED_BYTE_32_WIDETAG
                case SIMPLE_ARRAY_SIGNED_BYTE_32_WIDETAG:
 #endif
+#ifdef SIMPLE_ARRAY_SIGNED_BYTE_61_WIDETAG
+               case SIMPLE_ARRAY_SIGNED_BYTE_61_WIDETAG:
+#endif
+#ifdef SIMPLE_ARRAY_SIGNED_BYTE_64_WIDETAG
+               case SIMPLE_ARRAY_SIGNED_BYTE_64_WIDETAG:
+#endif
                case SIMPLE_ARRAY_SINGLE_FLOAT_WIDETAG:
                case SIMPLE_ARRAY_DOUBLE_FLOAT_WIDETAG:
 #ifdef SIMPLE_ARRAY_COMPLEX_LONG_FLOAT_WIDETAG
@@ -3465,15 +3355,15 @@ verify_gc(void)
      * Some counts of lispobjs are called foo_count; it might be good
      * to grep for all foo_size and rename the appropriate ones to
      * foo_count. */
-    int read_only_space_size =
+    long read_only_space_size =
        (lispobj*)SymbolValue(READ_ONLY_SPACE_FREE_POINTER,0)
        - (lispobj*)READ_ONLY_SPACE_START;
-    int static_space_size =
+    long static_space_size =
        (lispobj*)SymbolValue(STATIC_SPACE_FREE_POINTER,0)
        - (lispobj*)STATIC_SPACE_START;
     struct thread *th;
     for_each_thread(th) {
-    int binding_stack_size =
+    long binding_stack_size =
            (lispobj*)SymbolValue(BINDING_STACK_POINTER,th)
            - (lispobj*)th->binding_stack_start;
        verify_space(th->binding_stack_start, binding_stack_size);
@@ -3488,10 +3378,10 @@ verify_generation(int  generation)
     int i;
 
     for (i = 0; i < last_free_page; i++) {
-       if ((page_table[i].allocated != FREE_PAGE)
+       if ((page_table[i].allocated != FREE_PAGE_FLAG)
            && (page_table[i].bytes_used != 0)
            && (page_table[i].gen == generation)) {
-           int last_page;
+           long last_page;
            int region_allocation = page_table[i].allocated;
 
            /* This should be the start of a contiguous block */
@@ -3505,8 +3395,8 @@ verify_generation(int  generation)
            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 */
+               if ((page_table[last_page].bytes_used < PAGE_BYTES)
+                   /* Or it is PAGE_BYTES and is the last in the block */
                    || (page_table[last_page+1].allocated != region_allocation)
                    || (page_table[last_page+1].bytes_used == 0)
                    || (page_table[last_page+1].gen != generation)
@@ -3514,7 +3404,7 @@ verify_generation(int  generation)
                    break;
 
            verify_space(page_address(i), (page_table[last_page].bytes_used
-                                          + (last_page-i)*4096)/4);
+                                          + (last_page-i)*PAGE_BYTES)/N_WORD_BYTES);
            i = last_page;
        }
     }
@@ -3524,26 +3414,26 @@ verify_generation(int  generation)
 static void
 verify_zero_fill(void)
 {
-    int page;
+    long page;
 
     for (page = 0; page < last_free_page; page++) {
-       if (page_table[page].allocated == FREE_PAGE) {
+       if (page_table[page].allocated == FREE_PAGE_FLAG) {
            /* The whole page should be zero filled. */
-           int *start_addr = (int *)page_address(page);
-           int size = 1024;
-           int i;
+           long *start_addr = (long *)page_address(page);
+           long size = 1024;
+           long i;
            for (i = 0; i < size; i++) {
                if (start_addr[i] != 0) {
                    lose("free page not zero at %x", start_addr + i);
                }
            }
        } else {
-           int free_bytes = 4096 - page_table[page].bytes_used;
+           long free_bytes = PAGE_BYTES - page_table[page].bytes_used;
            if (free_bytes > 0) {
-               int *start_addr = (int *)((unsigned)page_address(page)
+               long *start_addr = (long *)((unsigned)page_address(page)
                                          + page_table[page].bytes_used);
-               int size = free_bytes / 4;
-               int i;
+               long size = free_bytes / N_WORD_BYTES;
+               long i;
                for (i = 0; i < size; i++) {
                    if (start_addr[i] != 0) {
                        lose("free region not zero at %x", start_addr + i);
@@ -3567,7 +3457,7 @@ gencgc_verify_zero_fill(void)
 static void
 verify_dynamic_space(void)
 {
-    int i;
+    long i;
 
     for (i = 0; i < NUM_GENERATIONS; i++)
        verify_generation(i);
@@ -3580,20 +3470,21 @@ verify_dynamic_space(void)
 static void
 write_protect_generation_pages(int generation)
 {
-    int i;
+    long i;
 
     gc_assert(generation < NUM_GENERATIONS);
 
     for (i = 0; i < last_free_page; i++)
-       if ((page_table[i].allocated == BOXED_PAGE)
+       if ((page_table[i].allocated == BOXED_PAGE_FLAG)
            && (page_table[i].bytes_used != 0)
+           && !page_table[i].dont_move
            && (page_table[i].gen == generation))  {
            void *page_start;
 
            page_start = (void *)page_address(i);
 
            os_protect(page_start,
-                      4096,
+                      PAGE_BYTES,
                       OS_VM_PROT_READ | OS_VM_PROT_EXECUTE);
 
            /* Note the page as protected in the page tables. */
@@ -3630,8 +3521,9 @@ garbage_collect_generation(int generation, int raise)
      * temporary generation (NUM_GENERATIONS), and lowered when
      * done. Set up this new generation. There should be no pages
      * allocated to it yet. */
-    if (!raise)
-       gc_assert(generations[NUM_GENERATIONS].bytes_allocated == 0);
+    if (!raise) {
+        gc_assert(generations[NUM_GENERATIONS].bytes_allocated == 0);
+    }
 
     /* Set the global src and dest. generations */
     from_space = generation;
@@ -3650,7 +3542,8 @@ 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
@@ -3660,43 +3553,56 @@ garbage_collect_generation(int generation, int raise)
     unprotect_oldspace();
 
     /* 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;
+       void **esp=(void **)-1;
 #ifdef LISP_FEATURE_SB_THREAD
-       struct user_regs_struct regs;
-       if(ptrace(PTRACE_GETREGS,th->pid,0,&regs)){
-           /* probably doesn't exist any more. */
-           fprintf(stderr,"child pid %d, %s\n",th->pid,strerror(errno));
-           perror("PTRACE_GETREGS");
+       long i,free;
+       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_SP);
+               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);
+                   }
+               }
+           }
        }
-       preserve_pointer(regs.ebx);
-       preserve_pointer(regs.ecx);
-       preserve_pointer(regs.edx);
-       preserve_pointer(regs.esi);
-       preserve_pointer(regs.edi);
-       preserve_pointer(regs.ebp);
-       preserve_pointer(regs.eax);
-#endif
-       for (ptr = th->control_stack_end;
-#ifdef LISP_FEATURE_SB_THREAD
-            ptr > regs.esp;
 #else
-            ptr > (void **)&raise;
+       esp = (void **) &raise;
 #endif
-            ptr--) {
+       for (ptr = (void **)th->control_stack_end; ptr > esp;  ptr--) {
            preserve_pointer(*ptr);
        }
     }
 
-#if QSHOW
+#ifdef QSHOW
     if (gencgc_verbose > 1) {
-       int num_dont_move_pages = count_dont_move_pages();
+       long num_dont_move_pages = count_dont_move_pages();
        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);
+               num_dont_move_pages * PAGE_BYTES);
     }
 #endif
 
@@ -3784,8 +3690,8 @@ garbage_collect_generation(int generation, int raise)
     /* As a check re-scavenge the newspace once; no new objects should
      * be found. */
     {
-       int old_bytes_allocated = bytes_allocated;
-       int bytes_allocated;
+       long old_bytes_allocated = bytes_allocated;
+       long bytes_allocated;
 
        /* Start with a full scavenge. */
        scavenge_newspace_generation_one_scan(new_space);
@@ -3848,21 +3754,21 @@ garbage_collect_generation(int generation, int raise)
 }
 
 /* Update last_free_page, then SymbolValue(ALLOCATION_POINTER). */
-int
+long
 update_x86_dynamic_space_free_pointer(void)
 {
-    int last_page = -1;
-    int i;
+    long last_page = -1;
+    long i;
 
-    for (i = 0; i < NUM_PAGES; i++)
-       if ((page_table[i].allocated != FREE_PAGE)
+    for (i = 0; i < last_free_page; i++)
+       if ((page_table[i].allocated != FREE_PAGE_FLAG)
            && (page_table[i].bytes_used != 0))
            last_page = i;
 
     last_free_page = last_page+1;
 
     SetSymbolValue(ALLOCATION_POINTER,
-                  (lispobj)(((char *)heap_base) + last_free_page*4096),0);
+                  (lispobj)(((char *)heap_base) + last_free_page*PAGE_BYTES),0);
     return 0; /* dummy value: return something ... */
 }
 
@@ -3881,7 +3787,7 @@ collect_garbage(unsigned last_gen)
     int gen = 0;
     int raise;
     int gen_to_wp;
-    int i;
+    long i;
 
     FSHOW((stderr, "/entering collect_garbage(%d)\n", last_gen));
 
@@ -3984,7 +3890,10 @@ collect_garbage(unsigned last_gen)
     gc_alloc_generation = 0;
 
     update_x86_dynamic_space_free_pointer();
-
+    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");
 }
 
@@ -3996,33 +3905,33 @@ collect_garbage(unsigned last_gen)
 void
 gc_free_heap(void)
 {
-    int page;
+    long page;
 
     if (gencgc_verbose > 1)
        SHOW("entering gc_free_heap");
 
     for (page = 0; page < NUM_PAGES; page++) {
        /* Skip free pages which should already be zero filled. */
-       if (page_table[page].allocated != FREE_PAGE) {
+       if (page_table[page].allocated != FREE_PAGE_FLAG) {
            void *page_start, *addr;
 
            /* Mark the page free. The other slots are assumed invalid
-            * when it is a FREE_PAGE and bytes_used is 0 and it
+            * when it is a FREE_PAGE_FLAG and bytes_used is 0 and it
             * should not be write-protected -- except that the
             * generation is used for the current region but it sets
             * that up. */
-           page_table[page].allocated = FREE_PAGE;
+           page_table[page].allocated = FREE_PAGE_FLAG;
            page_table[page].bytes_used = 0;
 
            /* Zero the page. */
            page_start = (void *)page_address(page);
 
            /* First, remove any write-protection. */
-           os_protect(page_start, 4096, OS_VM_PROT_ALL);
+           os_protect(page_start, PAGE_BYTES, OS_VM_PROT_ALL);
            page_table[page].write_protected = 0;
 
-           os_invalidate(page_start,4096);
-           addr = os_validate(page_start,4096);
+           os_invalidate(page_start,PAGE_BYTES);
+           addr = os_validate(page_start,PAGE_BYTES);
            if (addr == NULL || addr != page_start) {
                lose("gc_free_heap: page moved, 0x%08x ==> 0x%08x",
                     page_start,
@@ -4030,10 +3939,10 @@ gc_free_heap(void)
            }
        } else if (gencgc_zero_check_during_free_heap) {
            /* Double-check that the page is zero filled. */
-           int *page_start, i;
-           gc_assert(page_table[page].allocated == FREE_PAGE);
+           long *page_start, i;
+           gc_assert(page_table[page].allocated == FREE_PAGE_FLAG);
            gc_assert(page_table[page].bytes_used == 0);
-           page_start = (int *)page_address(page);
+           page_start = (long *)page_address(page);
            for (i=0; i<1024; i++) {
                if (page_start[i] != 0) {
                    lose("free region not zero at %x", page_start + i);
@@ -4079,7 +3988,7 @@ gc_free_heap(void)
 void
 gc_init(void)
 {
-    int i;
+    long i;
 
     gc_init_tables();
     scavtab[SIMPLE_VECTOR_WIDETAG] = scav_vector;
@@ -4091,7 +4000,7 @@ gc_init(void)
     /* Initialize each page structure. */
     for (i = 0; i < NUM_PAGES; i++) {
        /* Initialize all pages as free. */
-       page_table[i].allocated = FREE_PAGE;
+       page_table[i].allocated = FREE_PAGE_FLAG;
        page_table[i].bytes_used = 0;
 
        /* Pages are not write-protected at startup. */
@@ -4130,32 +4039,35 @@ gc_init(void)
 /*  Pick up the dynamic space from after a core load.
  *
  *  The ALLOCATION_POINTER points to the end of the dynamic space.
- *
- *  XX A scan is needed to identify the closest first objects for pages. */
+ */
+
 static void
 gencgc_pickup_dynamic(void)
 {
-    int page = 0;
-    int addr = DYNAMIC_SPACE_START;
-    int alloc_ptr = SymbolValue(ALLOCATION_POINTER,0);
+    long page = 0;
+    long alloc_ptr = SymbolValue(ALLOCATION_POINTER,0);
+    lispobj *prev=(lispobj *)page_address(page);
 
-    /* Initialize the first region. */
     do {
-       page_table[page].allocated = BOXED_PAGE;
+       lispobj *first,*ptr= (lispobj *)page_address(page);
+       page_table[page].allocated = BOXED_PAGE_FLAG;
        page_table[page].gen = 0;
-       page_table[page].bytes_used = 4096;
+       page_table[page].bytes_used = PAGE_BYTES;
        page_table[page].large_object = 0;
+
+       first=gc_search_space(prev,(ptr+2)-prev,ptr);
+       if(ptr == first)  prev=ptr; 
        page_table[page].first_object_offset =
-           (void *)DYNAMIC_SPACE_START - page_address(page);
-       addr += 4096;
+           (void *)prev - page_address(page);
        page++;
-    } while (addr < alloc_ptr);
+    } while (page_address(page) < alloc_ptr);
 
-    generations[0].bytes_allocated = 4096*page;
-    bytes_allocated = 4096*page;
+    generations[0].bytes_allocated = PAGE_BYTES*page;
+    bytes_allocated = PAGE_BYTES*page;
 
 }
 
+
 void
 gc_initialize_pointers(void)
 {
@@ -4165,7 +4077,6 @@ gc_initialize_pointers(void)
 
 \f
 
-extern boolean maybe_gc_pending ;
 /* alloc(..) is the external interface for memory allocation. It
  * allocates to generation 0. It is not called from within the garbage
  * collector as it is only external uses that need the check for heap
@@ -4179,23 +4090,41 @@ extern boolean maybe_gc_pending ;
  * region is full, so in most cases it's not needed. */
 
 char *
-alloc(int nbytes)
+alloc(long nbytes)
 {
     struct thread *th=arch_os_get_current_thread();
-    struct alloc_region *region= 
+    struct alloc_region *region=
+#ifdef LISP_FEATURE_SB_THREAD
        th ? &(th->alloc_region) : &boxed_region; 
+#else
+        &boxed_region; 
+#endif
     void *new_obj;
     void *new_free_pointer;
-
+    gc_assert(nbytes>0);
     /* Check for alignment allocation problems. */
-    gc_assert((((unsigned)region->free_pointer & 0x7) == 0)
-             && ((nbytes & 0x7) == 0));
+    gc_assert((((unsigned)region->free_pointer & LOWTAG_MASK) == 0)
+             && ((nbytes & LOWTAG_MASK) == 0));
+#if 0
     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 */
-       gc_assert(SymbolValue(PSEUDO_ATOMIC_ATOMIC,th));
-
+#ifdef LISP_FEATURE_SB_THREAD
+       if(!SymbolValue(PSEUDO_ATOMIC_ATOMIC,th)) {
+           register u32 fs;
+           fprintf(stderr, "fatal error in thread 0x%x, tid=%ld\n",
+                   th,th->os_thread);
+           __asm__("movl %fs,%0" : "=r" (fs)  : );
+           fprintf(stderr, "fs is %x, th->tls_cookie=%x \n",
+                   debug_get_fs(),th->tls_cookie);
+           lose("If you see this message before 2004.01.31, mail details to sbcl-devel\n");
+       }
+#else
+    gc_assert(SymbolValue(PSEUDO_ATOMIC_ATOMIC,th));
+#endif
+#endif
+    
     /* maybe we can do this quickly ... */
     new_free_pointer = region->free_pointer + nbytes;
     if (new_free_pointer <= region->end_addr) {
@@ -4208,54 +4137,38 @@ alloc(int nbytes)
      * we should GC in the near future
      */
     if (auto_gc_trigger && bytes_allocated > auto_gc_trigger) {
-       auto_gc_trigger *= 2;
-       /* set things up so that GC happens when we finish the PA
-        * section.  */
-       maybe_gc_pending=1;
-       SetSymbolValue(PSEUDO_ATOMIC_INTERRUPTED, make_fixnum(1),th);
+        struct thread *thread=arch_os_get_current_thread();
+        /* Don't flood the system with interrupts if the need to gc is
+         * already noted. This can happen for example when SUB-GC
+         * allocates or after a gc triggered in a WITHOUT-GCING. */
+        if (SymbolValue(NEED_TO_COLLECT_GARBAGE,thread) == NIL) {
+            /* 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;
+            sigset_t new_mask,old_mask;
+            sigemptyset(&new_mask);
+            sigaddset_blockable(&new_mask);
+            thread_sigmask(SIG_BLOCK,&new_mask,&old_mask);
+
+            if((!data->pending_handler) &&
+               maybe_defer_handler(interrupt_maybe_gc_int,data,0,0,0)) {
+                /* Leave the signals blocked just as if it was
+                 * deferred the normal way and set the
+                 * pending_mask. */
+                sigcopyset(&(data->pending_mask),&old_mask);
+                SetSymbolValue(NEED_TO_COLLECT_GARBAGE,T,thread);
+            } else {
+                thread_sigmask(SIG_SETMASK,&old_mask,0);
+            }
+        }
     }
     new_obj = gc_alloc_with_region(nbytes,0,region,0);
     return (new_obj);
 }
-
-\f
-/*
- * noise to manipulate the gc trigger stuff
- */
-
-void
-set_auto_gc_trigger(os_vm_size_t dynamic_usage)
-{
-    auto_gc_trigger += dynamic_usage;
-}
-
-void
-clear_auto_gc_trigger(void)
-{
-    auto_gc_trigger = 0;
-}
-\f
-/* Find the code object for the given pc, or return NULL on failure.
- *
- * FIXME: PC shouldn't be lispobj*, should it? Maybe void*? */
-lispobj *
-component_ptr_from_pc(lispobj *pc)
-{
-    lispobj *object = NULL;
-
-    if ( (object = search_read_only_space(pc)) )
-       ;
-    else if ( (object = search_static_space(pc)) )
-       ;
-    else
-       object = search_dynamic_space(pc);
-
-    if (object) /* if we found something */
-       if (widetag_of(*object) == CODE_HEADER_WIDETAG) /* if it's a code object */
-           return(object);
-
-    return (NULL);
-}
 \f
 /*
  * shared support for the OS-dependent signal handlers which
@@ -4277,9 +4190,9 @@ void unhandled_sigmemoryfault(void);
 int
 gencgc_handle_wp_violation(void* fault_addr)
 {
-    int  page_index = find_page_index(fault_addr);
+    long  page_index = find_page_index(fault_addr);
 
-#if defined QSHOW_SIGNALS
+#ifdef QSHOW_SIGNALS
     FSHOW((stderr, "heap WP violation? fault_addr=%x, page_index=%d\n",
           fault_addr, page_index));
 #endif
@@ -4309,10 +4222,9 @@ gencgc_handle_wp_violation(void* fault_addr)
             */
            if(page_table[page_index].write_protected_cleared != 1) 
                lose("fault in heap page not marked as write-protected");
-           
-           /* Don't worry, we can handle it. */
-           return 1;
        }
+       /* Don't worry, we can handle it. */
+       return 1;
     }
 }
 /* This is to be called when we catch a SIGSEGV/SIGBUS, determine that
@@ -4323,7 +4235,7 @@ void
 unhandled_sigmemoryfault()
 {}
 
-gc_alloc_update_all_page_tables(void)
+void gc_alloc_update_all_page_tables(void)
 {
     /* Flush the alloc regions updating the tables. */
     struct thread *th;