0.8alpha.0.14
[sbcl.git] / src / runtime / purify.c
index 677db6d..642dea9 100644 (file)
  * files for more information.
  */
 
-/*
- * $Header$
- */
-
 #include <stdio.h>
 #include <sys/types.h>
 #include <stdlib.h>
+#include <strings.h>
+#if (defined(LISP_FEATURE_SB_THREAD) && defined(LISP_FEATURE_LINUX))
+#include <sys/ptrace.h>
+#include <linux/user.h>
+#endif
+#include <errno.h>
 
 #include "runtime.h"
 #include "os.h"
 #include "interrupt.h"
 #include "purify.h"
 #include "interr.h"
-#ifdef GENCGC
-#include "gencgc.h"
-#endif
+#include "gc.h"
+#include "gc-internal.h"
+#include "thread.h"
+#include "genesis/primitive-objects.h"
+#include "genesis/static-symbols.h"
 
-#undef PRINTNOISE
+#define PRINTNOISE
 
-#if defined(ibmrt) || defined(__i386__)
+#if defined(__i386__)
+/* again, what's so special about the x86 that this is differently
+ * visible there than on other platforms? -dan 20010125 
+ */
 static lispobj *dynamic_space_free_pointer;
 #endif
+extern unsigned long bytes_consed_between_gcs;
 
 #define gc_abort() \
   lose("GC invariant lost, file \"%s\", line %d", __FILE__, __LINE__)
@@ -63,7 +71,8 @@ static lispobj *pscav(lispobj *addr, int nwords, boolean constant);
 #define LATERBLOCKSIZE 1020
 #define LATERMAXCOUNT 10
 
-static struct later {
+static struct
+later {
     struct later *next;
     union {
         lispobj *ptr;
@@ -75,18 +84,19 @@ static int later_count = 0;
 #define CEILING(x,y) (((x) + ((y) - 1)) & (~((y) - 1)))
 #define NWORDS(x,y) (CEILING((x),(y)) / (y))
 
+/* FIXME: Shouldn't this be defined in sbcl.h?  See also notes in
+ * cheneygc.c */
+
 #ifdef sparc
-#define RAW_ADDR_OFFSET 0
+#define FUN_RAW_ADDR_OFFSET 0
 #else
-#define RAW_ADDR_OFFSET (6*sizeof(lispobj) - type_FunctionPointer)
+#define FUN_RAW_ADDR_OFFSET (6*sizeof(lispobj) - FUN_POINTER_LOWTAG)
 #endif
 \f
 static boolean
 forwarding_pointer_p(lispobj obj)
 {
-    lispobj *ptr;
-
-    ptr = (lispobj *)obj;
+    lispobj *ptr = native_pointer(obj);
 
     return ((static_end <= ptr && ptr <= static_free) ||
             (read_only_end <= ptr && ptr <= read_only_free));
@@ -96,11 +106,9 @@ static boolean
 dynamic_pointer_p(lispobj ptr)
 {
 #ifndef __i386__
-    /* KLUDGE: This has an implicit dependence on the ordering of
-     * address spaces, and is therefore basically wrong. I'd fix it,
-     * but I don't have a non-386 port to test it on. Porters are
-     * encouraged to fix it. -- WHN 2000-10-17 */
-    return (ptr >= (lispobj)DYNAMIC_SPACE_START);
+    return (ptr >= (lispobj)current_dynamic_space
+           &&
+           ptr < (lispobj)dynamic_space_free_pointer);
 #else
     /* Be more conservative, and remember, this is a maybe. */
     return (ptr >= (lispobj)DYNAMIC_SPACE_START
@@ -112,110 +120,9 @@ dynamic_pointer_p(lispobj ptr)
 \f
 #ifdef __i386__
 
-#ifdef WANT_CGC
-/* original x86/CGC stack scavenging code by Paul Werkowski */
-
-static int
-maybe_can_move_p(lispobj thing)
-{
-  lispobj *thingp,header;
-  if (dynamic_pointer_p(thing)) { /* in dynamic space */
-    thingp = (lispobj*)PTR(thing);
-    header = *thingp;
-    if(Pointerp(header) && forwarding_pointer_p(header))
-      return -1;               /* must change it */
-    if(LowtagOf(thing) == type_ListPointer)
-      return type_ListPointer; /* can we check this somehow */
-    else if (thing & 3) {      /* not fixnum */
-      int kind = TypeOf(header);
-      /* printf(" %x %x",header,kind); */
-      switch (kind) {          /* something with a header */
-      case type_Bignum:
-      case type_SingleFloat:
-      case type_DoubleFloat:
-#ifdef type_LongFloat
-      case type_LongFloat:
-#endif
-      case type_Sap:
-      case type_SimpleVector:
-      case type_SimpleString:
-      case type_SimpleBitVector:
-      case type_SimpleArrayUnsignedByte2:
-      case type_SimpleArrayUnsignedByte4:
-      case type_SimpleArrayUnsignedByte8:
-      case type_SimpleArrayUnsignedByte16:
-      case type_SimpleArrayUnsignedByte32:
-#ifdef type_SimpleArraySignedByte8
-      case type_SimpleArraySignedByte8:
-#endif
-#ifdef type_SimpleArraySignedByte16
-      case type_SimpleArraySignedByte16:
-#endif
-#ifdef type_SimpleArraySignedByte30
-      case type_SimpleArraySignedByte30:
-#endif
-#ifdef type_SimpleArraySignedByte32
-      case type_SimpleArraySignedByte32:
-#endif
-      case type_SimpleArraySingleFloat:
-      case type_SimpleArrayDoubleFloat:
-#ifdef type_SimpleArrayLongFloat
-      case type_SimpleArrayLongFloat:
-#endif
-#ifdef type_SimpleArrayComplexSingleFloat
-      case type_SimpleArrayComplexSingleFloat:
-#endif
-#ifdef type_SimpleArrayComplexDoubleFloat
-      case type_SimpleArrayComplexDoubleFloat:
-#endif
-#ifdef type_SimpleArrayComplexLongFloat
-      case type_SimpleArrayComplexLongFloat:
-#endif
-      case type_CodeHeader:
-      case type_FunctionHeader:
-      case type_ClosureFunctionHeader:
-      case type_ReturnPcHeader:
-      case type_ClosureHeader:
-      case type_FuncallableInstanceHeader:
-      case type_InstanceHeader:
-      case type_ValueCellHeader:
-      case type_ByteCodeFunction:
-      case type_ByteCodeClosure:
-      case type_WeakPointer:
-      case type_Fdefn:
-       return kind;
-       break;
-      default:
-       return 0;
-      }}}
-  return 0;
-}
-
-static int pverbose=0;
-#define PVERBOSE pverbose
-static void
-carefully_pscav_stack(lispobj*lowaddr, lispobj*base)
-{
-  lispobj*sp = lowaddr;
-  while (sp < base)
-    { int k;
-      lispobj thing = *sp;
-      if((unsigned)thing & 0x3)        /* may be pointer */
-       {
-         /* need to check for valid float/double? */
-         k = maybe_can_move_p(thing);
-         if(PVERBOSE)printf("%8x %8x %d\n",sp, thing, k);
-         if(k)
-           pscav(sp, 1, 0);
-       }
-      sp++;
-    }
-}
-#endif
-
-#ifdef GENCGC
+#ifdef LISP_FEATURE_GENCGC
 /*
- * Enhanced x86/GENCGC stack scavenging by Douglas Crosher.
+ * enhanced x86/GENCGC stack scavenging by Douglas Crosher
  *
  * Scavenging the stack on the i386 is problematic due to conservative
  * roots and raw return addresses. Here it is handled in two passes:
@@ -226,197 +133,211 @@ carefully_pscav_stack(lispobj*lowaddr, lispobj*base)
 
 static unsigned pointer_filter_verbose = 0;
 
+/* FIXME: This is substantially the same code as
+ * possibly_valid_dynamic_space_pointer in gencgc.c.  The only
+ * relevant difference seems to be that the gencgc code also checks
+ * for raw pointers into Code objects */
+
 static int
 valid_dynamic_space_pointer(lispobj *pointer, lispobj *start_addr)
 {
-  /* If it's not a return address then it needs to be a valid Lisp
-   * pointer. */
-  if (!Pointerp((lispobj)pointer))
-    return 0;
+    /* If it's not a return address then it needs to be a valid Lisp
+     * pointer. */
+    if (!is_lisp_pointer((lispobj)pointer))
+       return 0;
 
-  /* Check that the object pointed to is consistent with the pointer
-   * low tag. */
-  switch (LowtagOf((lispobj)pointer)) {
-  case type_FunctionPointer:
-    /* Start_addr should be the enclosing code object, or a closure
-     * header. */
-    switch (TypeOf(*start_addr)) {
-    case type_CodeHeader:
-      /* This case is probably caught above. */
-      break;
-    case type_ClosureHeader:
-    case type_FuncallableInstanceHeader:
-    case type_ByteCodeFunction:
-    case type_ByteCodeClosure:
-      if ((int)pointer != ((int)start_addr+type_FunctionPointer)) {
+    /* Check that the object pointed to is consistent with the pointer
+     * low tag. */
+    switch (lowtag_of((lispobj)pointer)) {
+    case FUN_POINTER_LOWTAG:
+       /* Start_addr should be the enclosing code object, or a closure
+        * header. */
+       switch (widetag_of(*start_addr)) {
+       case CODE_HEADER_WIDETAG:
+           /* This case is probably caught above. */
+           break;
+       case CLOSURE_HEADER_WIDETAG:
+       case FUNCALLABLE_INSTANCE_HEADER_WIDETAG:
+           if ((int)pointer != ((int)start_addr+FUN_POINTER_LOWTAG)) {
+               if (pointer_filter_verbose) {
+                   fprintf(stderr,"*Wf2: %x %x %x\n", (unsigned int) pointer, 
+                           (unsigned int) start_addr, *start_addr);
+               }
+               return 0;
+           }
+           break;
+       default:
+           if (pointer_filter_verbose) {
+               fprintf(stderr,"*Wf3: %x %x %x\n", (unsigned int) pointer, 
+                       (unsigned int) start_addr, *start_addr);
+           }
+           return 0;
+       }
+       break;
+    case LIST_POINTER_LOWTAG:
+       if ((int)pointer != ((int)start_addr+LIST_POINTER_LOWTAG)) {
+           if (pointer_filter_verbose)
+               fprintf(stderr,"*Wl1: %x %x %x\n", (unsigned int) pointer, 
+                       (unsigned int) start_addr, *start_addr);
+           return 0;
+       }
+       /* 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)
+           || (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)
+              || (widetag_of(start_addr[1]) == UNBOUND_MARKER_WIDETAG))) {
+           break;
+       } else {
+           if (pointer_filter_verbose) {
+               fprintf(stderr,"*Wl2: %x %x %x\n", (unsigned int) pointer, 
+                       (unsigned int) start_addr, *start_addr);
+           }
+           return 0;
+       }
+    case INSTANCE_POINTER_LOWTAG:
+       if ((int)pointer != ((int)start_addr+INSTANCE_POINTER_LOWTAG)) {
+           if (pointer_filter_verbose) {
+               fprintf(stderr,"*Wi1: %x %x %x\n", (unsigned int) pointer, 
+                       (unsigned int) start_addr, *start_addr);
+           }
+           return 0;
+       }
+       if (widetag_of(start_addr[0]) != INSTANCE_HEADER_WIDETAG) {
+           if (pointer_filter_verbose) {
+               fprintf(stderr,"*Wi2: %x %x %x\n", (unsigned int) pointer, 
+                       (unsigned int) start_addr, *start_addr);
+           }
+           return 0;
+       }
+       break;
+    case OTHER_POINTER_LOWTAG:
+       if ((int)pointer != ((int)start_addr+OTHER_POINTER_LOWTAG)) {
+           if (pointer_filter_verbose) {
+               fprintf(stderr,"*Wo1: %x %x %x\n", (unsigned int) pointer, 
+                       (unsigned int) start_addr, *start_addr);
+           }
+           return 0;
+       }
+       /* Is it plausible? Not a cons. XXX should check the headers. */
+       if (is_lisp_pointer(start_addr[0]) || ((start_addr[0] & 3) == 0)) {
+           if (pointer_filter_verbose) {
+               fprintf(stderr,"*Wo2: %x %x %x\n", (unsigned int) pointer, 
+                       (unsigned int) start_addr, *start_addr);
+           }
+           return 0;
+       }
+       switch (widetag_of(start_addr[0])) {
+       case UNBOUND_MARKER_WIDETAG:
+       case BASE_CHAR_WIDETAG:
+           if (pointer_filter_verbose) {
+               fprintf(stderr,"*Wo3: %x %x %x\n", (unsigned int) pointer, 
+                       (unsigned int) start_addr, *start_addr);
+           }
+           return 0;
+
+           /* only pointed to by function pointers? */
+       case CLOSURE_HEADER_WIDETAG:
+       case FUNCALLABLE_INSTANCE_HEADER_WIDETAG:
+           if (pointer_filter_verbose) {
+               fprintf(stderr,"*Wo4: %x %x %x\n", (unsigned int) pointer, 
+                       (unsigned int) start_addr, *start_addr);
+           }
+           return 0;
+
+       case INSTANCE_HEADER_WIDETAG:
+           if (pointer_filter_verbose) {
+               fprintf(stderr,"*Wo5: %x %x %x\n", (unsigned int) pointer, 
+                       (unsigned int) start_addr, *start_addr);
+           }
+           return 0;
+
+           /* the valid other immediate pointer objects */
+       case SIMPLE_VECTOR_WIDETAG:
+       case RATIO_WIDETAG:
+       case COMPLEX_WIDETAG:
+#ifdef COMPLEX_SINGLE_FLOAT_WIDETAG
+       case COMPLEX_SINGLE_FLOAT_WIDETAG:
+#endif
+#ifdef COMPLEX_DOUBLE_FLOAT_WIDETAG
+       case COMPLEX_DOUBLE_FLOAT_WIDETAG:
+#endif
+#ifdef COMPLEX_LONG_FLOAT_WIDETAG
+       case COMPLEX_LONG_FLOAT_WIDETAG:
+#endif
+       case SIMPLE_ARRAY_WIDETAG:
+       case COMPLEX_STRING_WIDETAG:
+       case COMPLEX_BIT_VECTOR_WIDETAG:
+       case COMPLEX_VECTOR_WIDETAG:
+       case COMPLEX_ARRAY_WIDETAG:
+       case VALUE_CELL_HEADER_WIDETAG:
+       case SYMBOL_HEADER_WIDETAG:
+       case FDEFN_WIDETAG:
+       case CODE_HEADER_WIDETAG:
+       case BIGNUM_WIDETAG:
+       case SINGLE_FLOAT_WIDETAG:
+       case DOUBLE_FLOAT_WIDETAG:
+#ifdef LONG_FLOAT_WIDETAG
+       case LONG_FLOAT_WIDETAG:
+#endif
+       case SIMPLE_STRING_WIDETAG:
+       case SIMPLE_BIT_VECTOR_WIDETAG:
+       case SIMPLE_ARRAY_UNSIGNED_BYTE_2_WIDETAG:
+       case SIMPLE_ARRAY_UNSIGNED_BYTE_4_WIDETAG:
+       case SIMPLE_ARRAY_UNSIGNED_BYTE_8_WIDETAG:
+       case SIMPLE_ARRAY_UNSIGNED_BYTE_16_WIDETAG:
+       case SIMPLE_ARRAY_UNSIGNED_BYTE_32_WIDETAG:
+#ifdef SIMPLE_ARRAY_SIGNED_BYTE_8_WIDETAG
+       case SIMPLE_ARRAY_SIGNED_BYTE_8_WIDETAG:
+#endif
+#ifdef SIMPLE_ARRAY_SIGNED_BYTE_16_WIDETAG
+       case SIMPLE_ARRAY_SIGNED_BYTE_16_WIDETAG:
+#endif
+#ifdef SIMPLE_ARRAY_SIGNED_BYTE_30_WIDETAG
+       case SIMPLE_ARRAY_SIGNED_BYTE_30_WIDETAG:
+#endif
+#ifdef SIMPLE_ARRAY_SIGNED_BYTE_32_WIDETAG
+       case SIMPLE_ARRAY_SIGNED_BYTE_32_WIDETAG:
+#endif
+       case SIMPLE_ARRAY_SINGLE_FLOAT_WIDETAG:
+       case SIMPLE_ARRAY_DOUBLE_FLOAT_WIDETAG:
+#ifdef SIMPLE_ARRAY_LONG_FLOAT_WIDETAG
+       case SIMPLE_ARRAY_LONG_FLOAT_WIDETAG:
+#endif
+#ifdef SIMPLE_ARRAY_COMPLEX_SINGLE_FLOAT_WIDETAG
+       case SIMPLE_ARRAY_COMPLEX_SINGLE_FLOAT_WIDETAG:
+#endif
+#ifdef SIMPLE_ARRAY_COMPLEX_DOUBLE_FLOAT_WIDETAG
+       case SIMPLE_ARRAY_COMPLEX_DOUBLE_FLOAT_WIDETAG:
+#endif
+#ifdef SIMPLE_ARRAY_COMPLEX_LONG_FLOAT_WIDETAG
+       case SIMPLE_ARRAY_COMPLEX_LONG_FLOAT_WIDETAG:
+#endif
+       case SAP_WIDETAG:
+       case WEAK_POINTER_WIDETAG:
+           break;
+
+       default:
+           if (pointer_filter_verbose) {
+               fprintf(stderr,"*Wo6: %x %x %x\n", (unsigned int) pointer, 
+                       (unsigned int) start_addr, *start_addr);
+           }
+           return 0;
+       }
+       break;
+    default:
        if (pointer_filter_verbose) {
-         fprintf(stderr,"*Wf2: %x %x %x\n", pointer, start_addr, *start_addr);
+           fprintf(stderr,"*W?: %x %x %x\n", (unsigned int) pointer, 
+                   (unsigned int) start_addr, *start_addr);
        }
        return 0;
-      }
-      break;
-    default:
-      if (pointer_filter_verbose) {
-       fprintf(stderr,"*Wf3: %x %x %x\n", pointer, start_addr, *start_addr);
-      }
-      return 0;
-    }
-    break;
-  case type_ListPointer:
-    if ((int)pointer != ((int)start_addr+type_ListPointer)) {
-      if (pointer_filter_verbose)
-       fprintf(stderr,"*Wl1: %x %x %x\n", pointer, start_addr, *start_addr);
-      return 0;
-    }
-    /* Is it plausible cons? */
-    if((Pointerp(start_addr[0])
-       || ((start_addr[0] & 3) == 0) /* fixnum */
-       || (TypeOf(start_addr[0]) == type_BaseChar)
-       || (TypeOf(start_addr[0]) == type_UnboundMarker))
-       && (Pointerp(start_addr[1])
-          || ((start_addr[1] & 3) == 0) /* fixnum */
-          || (TypeOf(start_addr[1]) == type_BaseChar)
-          || (TypeOf(start_addr[1]) == type_UnboundMarker))) {
-      break;
-    } else {
-      if (pointer_filter_verbose) {
-       fprintf(stderr,"*Wl2: %x %x %x\n", pointer, start_addr, *start_addr);
-      }
-      return 0;
     }
-  case type_InstancePointer:
-    if ((int)pointer != ((int)start_addr+type_InstancePointer)) {
-      if (pointer_filter_verbose) {
-       fprintf(stderr,"*Wi1: %x %x %x\n", pointer, start_addr, *start_addr);
-      }
-      return 0;
-    }
-    if (TypeOf(start_addr[0]) != type_InstanceHeader) {
-      if (pointer_filter_verbose) {
-       fprintf(stderr,"*Wi2: %x %x %x\n", pointer, start_addr, *start_addr);
-      }
-      return 0;
-    }
-    break;
-  case type_OtherPointer:
-    if ((int)pointer != ((int)start_addr+type_OtherPointer)) {
-      if (pointer_filter_verbose) {
-       fprintf(stderr,"*Wo1: %x %x %x\n", pointer, start_addr, *start_addr);
-      }
-      return 0;
-    }
-    /* Is it plausible?  Not a cons. X should check the headers. */
-    if(Pointerp(start_addr[0]) || ((start_addr[0] & 3) == 0)) {
-      if (pointer_filter_verbose) {
-       fprintf(stderr,"*Wo2: %x %x %x\n", pointer, start_addr, *start_addr);
-      }
-      return 0;
-    }
-    switch (TypeOf(start_addr[0])) {
-    case type_UnboundMarker:
-    case type_BaseChar:
-      if (pointer_filter_verbose) {
-       fprintf(stderr,"*Wo3: %x %x %x\n", pointer, start_addr, *start_addr);
-      }
-      return 0;
-
-      /* only pointed to by function pointers? */
-    case type_ClosureHeader:
-    case type_FuncallableInstanceHeader:
-    case type_ByteCodeFunction:
-    case type_ByteCodeClosure:
-      if (pointer_filter_verbose) {
-       fprintf(stderr,"*Wo4: %x %x %x\n", pointer, start_addr, *start_addr);
-      }
-      return 0;
-
-    case type_InstanceHeader:
-      if (pointer_filter_verbose) {
-       fprintf(stderr,"*Wo5: %x %x %x\n", pointer, start_addr, *start_addr);
-      }
-      return 0;
-
-      /* the valid other immediate pointer objects */
-    case type_SimpleVector:
-    case type_Ratio:
-    case type_Complex:
-#ifdef type_ComplexSingleFloat
-    case type_ComplexSingleFloat:
-#endif
-#ifdef type_ComplexDoubleFloat
-    case type_ComplexDoubleFloat:
-#endif
-#ifdef type_ComplexLongFloat
-    case type_ComplexLongFloat:
-#endif
-    case type_SimpleArray:
-    case type_ComplexString:
-    case type_ComplexBitVector:
-    case type_ComplexVector:
-    case type_ComplexArray:
-    case type_ValueCellHeader:
-    case type_SymbolHeader:
-    case type_Fdefn:
-    case type_CodeHeader:
-    case type_Bignum:
-    case type_SingleFloat:
-    case type_DoubleFloat:
-#ifdef type_LongFloat
-    case type_LongFloat:
-#endif
-    case type_SimpleString:
-    case type_SimpleBitVector:
-    case type_SimpleArrayUnsignedByte2:
-    case type_SimpleArrayUnsignedByte4:
-    case type_SimpleArrayUnsignedByte8:
-    case type_SimpleArrayUnsignedByte16:
-    case type_SimpleArrayUnsignedByte32:
-#ifdef type_SimpleArraySignedByte8
-    case type_SimpleArraySignedByte8:
-#endif
-#ifdef type_SimpleArraySignedByte16
-    case type_SimpleArraySignedByte16:
-#endif
-#ifdef type_SimpleArraySignedByte30
-    case type_SimpleArraySignedByte30:
-#endif
-#ifdef type_SimpleArraySignedByte32
-    case type_SimpleArraySignedByte32:
-#endif
-    case type_SimpleArraySingleFloat:
-    case type_SimpleArrayDoubleFloat:
-#ifdef type_SimpleArrayLongFloat
-    case type_SimpleArrayLongFloat:
-#endif
-#ifdef type_SimpleArrayComplexSingleFloat
-    case type_SimpleArrayComplexSingleFloat:
-#endif
-#ifdef type_SimpleArrayComplexDoubleFloat
-    case type_SimpleArrayComplexDoubleFloat:
-#endif
-#ifdef type_SimpleArrayComplexLongFloat
-    case type_SimpleArrayComplexLongFloat:
-#endif
-    case type_Sap:
-    case type_WeakPointer:
-      break;
 
-    default:
-      if (pointer_filter_verbose) {
-       fprintf(stderr,"*Wo6: %x %x %x\n", pointer, start_addr, *start_addr);
-      }
-      return 0;
-    }
-    break;
-  default:
-    if (pointer_filter_verbose) {
-      fprintf(stderr,"*W?: %x %x %x\n", pointer, start_addr, *start_addr);
-    }
-    return 0;
-  }
-
-  /* looks good */
-  return 1;
+    /* looks good */
+    return 1;
 }
 
 #define MAX_STACK_POINTERS 256
@@ -432,60 +353,66 @@ unsigned int num_valid_stack_ra_locations;
 static void
 setup_i386_stack_scav(lispobj *lowaddr, lispobj *base)
 {
-  lispobj *sp = lowaddr;
-  num_valid_stack_locations = 0;
-  num_valid_stack_ra_locations = 0;
-  for (sp = lowaddr; sp < base; sp++) {
-    lispobj thing = *sp;
-    /* Find the object start address */
-    lispobj *start_addr = search_dynamic_space((void *)thing);
-    if (start_addr) {
-      /* We need to allow raw pointers into Code objects for return
-       * addresses. This will also pick up pointers to functions in code
-       * objects. */
-      if (TypeOf(*start_addr) == type_CodeHeader) {
-       gc_assert(num_valid_stack_ra_locations < MAX_STACK_RETURN_ADDRESSES);
-       valid_stack_ra_locations[num_valid_stack_ra_locations] = sp;
-       valid_stack_ra_code_objects[num_valid_stack_ra_locations++] =
-         (lispobj *)((int)start_addr + type_OtherPointer);
-      } else {
-       if (valid_dynamic_space_pointer((void *)thing, start_addr)) {
-         gc_assert(num_valid_stack_locations < MAX_STACK_POINTERS);
-         valid_stack_locations[num_valid_stack_locations++] = sp;
+    lispobj *sp = lowaddr;
+    num_valid_stack_locations = 0;
+    num_valid_stack_ra_locations = 0;
+    for (sp = lowaddr; sp < base; sp++) {
+       lispobj thing = *sp;
+       /* Find the object start address */
+       lispobj *start_addr = search_dynamic_space((void *)thing);
+       if (start_addr) {
+           /* We need to allow raw pointers into Code objects for
+            * return addresses. This will also pick up pointers to
+            * functions in code objects. */
+           if (widetag_of(*start_addr) == CODE_HEADER_WIDETAG) {
+               /* FIXME asserting here is a really dumb thing to do.
+                * If we've overflowed some arbitrary static limit, we
+                * should just refuse to purify, instead of killing
+                * the whole lisp session
+                */
+               gc_assert(num_valid_stack_ra_locations <
+                         MAX_STACK_RETURN_ADDRESSES);
+               valid_stack_ra_locations[num_valid_stack_ra_locations] = sp;
+               valid_stack_ra_code_objects[num_valid_stack_ra_locations++] =
+                   (lispobj *)((int)start_addr + OTHER_POINTER_LOWTAG);
+           } else {
+               if (valid_dynamic_space_pointer((void *)thing, start_addr)) {
+                   gc_assert(num_valid_stack_locations < MAX_STACK_POINTERS);
+                   valid_stack_locations[num_valid_stack_locations++] = sp;
+               }
+           }
        }
-      }
     }
-  }
-  if (pointer_filter_verbose) {
-    fprintf(stderr, "number of valid stack pointers = %d\n",
-           num_valid_stack_locations);
-    fprintf(stderr, "number of stack return addresses = %d\n",
-           num_valid_stack_ra_locations);
-  }
+    if (pointer_filter_verbose) {
+       fprintf(stderr, "number of valid stack pointers = %d\n",
+               num_valid_stack_locations);
+       fprintf(stderr, "number of stack return addresses = %d\n",
+               num_valid_stack_ra_locations);
+    }
 }
 
 static void
 pscav_i386_stack(void)
 {
-  int i;
+    int i;
 
-  for (i = 0; i < num_valid_stack_locations; i++)
-    pscav(valid_stack_locations[i], 1, 0);
+    for (i = 0; i < num_valid_stack_locations; i++)
+       pscav(valid_stack_locations[i], 1, 0);
 
-  for (i = 0; i < num_valid_stack_ra_locations; i++) {
-    lispobj code_obj = (lispobj)valid_stack_ra_code_objects[i];
-    pscav(&code_obj, 1, 0);
-    if (pointer_filter_verbose) {
-      fprintf(stderr,"*C moved RA %x to %x; for code object %x to %x\n",
-             *valid_stack_ra_locations[i],
-             (int)(*valid_stack_ra_locations[i])
-             - ((int)valid_stack_ra_code_objects[i] - (int)code_obj),
-             valid_stack_ra_code_objects[i], code_obj);
+    for (i = 0; i < num_valid_stack_ra_locations; i++) {
+       lispobj code_obj = (lispobj)valid_stack_ra_code_objects[i];
+       pscav(&code_obj, 1, 0);
+       if (pointer_filter_verbose) {
+           fprintf(stderr,"*C moved RA %x to %x; for code object %x to %x\n",
+                   *valid_stack_ra_locations[i],
+                   (int)(*valid_stack_ra_locations[i])
+                   - ((int)valid_stack_ra_code_objects[i] - (int)code_obj),
+                   (unsigned int) valid_stack_ra_code_objects[i], code_obj);
+       }
+       *valid_stack_ra_locations[i] =
+           ((int)(*valid_stack_ra_locations[i])
+            - ((int)valid_stack_ra_code_objects[i] - (int)code_obj));
     }
-    *valid_stack_ra_locations[i] =
-      ((int)(*valid_stack_ra_locations[i])
-       - ((int)valid_stack_ra_code_objects[i] - (int)code_obj));
-  }
 }
 #endif
 #endif
@@ -520,7 +447,8 @@ pscav_later(lispobj *where, int count)
     }
 }
 
-static lispobj ptrans_boxed(lispobj thing, lispobj header, boolean constant)
+static lispobj
+ptrans_boxed(lispobj thing, lispobj header, boolean constant)
 {
     int nwords;
     lispobj result, *new, *old;
@@ -528,7 +456,7 @@ static lispobj ptrans_boxed(lispobj thing, lispobj header, boolean constant)
     nwords = 1 + HeaderValue(header);
 
     /* Allocate it */
-    old = (lispobj *)PTR(thing);
+    old = (lispobj *)native_pointer(thing);
     if (constant) {
         new = read_only_free;
         read_only_free += CEILING(nwords, 2);
@@ -542,7 +470,7 @@ static lispobj ptrans_boxed(lispobj thing, lispobj header, boolean constant)
     bcopy(old, new, nwords * sizeof(lispobj));
 
     /* Deposit forwarding pointer. */
-    result = (lispobj)new | LowtagOf(thing);
+    result = make_lispobj(new, lowtag_of(thing));
     *old = result;
 
     /* Scavenge it. */
@@ -552,12 +480,13 @@ static lispobj ptrans_boxed(lispobj thing, lispobj header, boolean constant)
 }
 
 /* We need to look at the layout to see whether it is a pure structure
- * class, and only then can we transport as constant. If it is pure, we can
- * ALWAYS transport as a constant. */
-static lispobj ptrans_instance(lispobj thing, lispobj header, boolean constant)
+ * class, and only then can we transport as constant. If it is pure,
+ * we can ALWAYS transport as a constant. */
+static lispobj
+ptrans_instance(lispobj thing, lispobj header, boolean constant)
 {
-    lispobj layout = ((struct instance *)PTR(thing))->slots[0];
-    lispobj pure = ((struct instance *)PTR(layout))->slots[15];
+    lispobj layout = ((struct instance *)native_pointer(thing))->slots[0];
+    lispobj pure = ((struct instance *)native_pointer(layout))->slots[15];
 
     switch (pure) {
     case T:
@@ -566,17 +495,18 @@ static lispobj ptrans_instance(lispobj thing, lispobj header, boolean constant)
        return (ptrans_boxed(thing, header, 0));
     case 0:
        {
-           /* Substructure: special case for the compact-info-envs, where
-            * the instance may have a point to the dynamic space placed
-            * into it (e.g. the cache-name slot), but the lists and arrays
-            * at the time of a purify can be moved to the RO space. */
+           /* Substructure: special case for the COMPACT-INFO-ENVs,
+            * where the instance may have a point to the dynamic
+            * space placed into it (e.g. the cache-name slot), but
+            * the lists and arrays at the time of a purify can be
+            * moved to the RO space. */
            int nwords;
            lispobj result, *new, *old;
 
            nwords = 1 + HeaderValue(header);
 
            /* Allocate it */
-           old = (lispobj *)PTR(thing);
+           old = (lispobj *)native_pointer(thing);
            new = static_free;
            static_free += CEILING(nwords, 2);
 
@@ -584,7 +514,7 @@ static lispobj ptrans_instance(lispobj thing, lispobj header, boolean constant)
            bcopy(old, new, nwords * sizeof(lispobj));
 
            /* Deposit forwarding pointer. */
-           result = (lispobj)new | LowtagOf(thing);
+           result = make_lispobj(new, lowtag_of(thing));
            *old = result;
 
            /* Scavenge it. */
@@ -594,10 +524,12 @@ static lispobj ptrans_instance(lispobj thing, lispobj header, boolean constant)
        }
     default:
        gc_abort();
+       return NIL; /* dummy value: return something ... */
     }
 }
 
-static lispobj ptrans_fdefn(lispobj thing, lispobj header)
+static lispobj
+ptrans_fdefn(lispobj thing, lispobj header)
 {
     int nwords;
     lispobj result, *new, *old, oldfn;
@@ -606,7 +538,7 @@ static lispobj ptrans_fdefn(lispobj thing, lispobj header)
     nwords = 1 + HeaderValue(header);
 
     /* Allocate it */
-    old = (lispobj *)PTR(thing);
+    old = (lispobj *)native_pointer(thing);
     new = static_free;
     static_free += CEILING(nwords, 2);
 
@@ -614,49 +546,51 @@ static lispobj ptrans_fdefn(lispobj thing, lispobj header)
     bcopy(old, new, nwords * sizeof(lispobj));
 
     /* Deposit forwarding pointer. */
-    result = (lispobj)new | LowtagOf(thing);
+    result = make_lispobj(new, lowtag_of(thing));
     *old = result;
 
     /* Scavenge the function. */
     fdefn = (struct fdefn *)new;
-    oldfn = fdefn->function;
-    pscav(&fdefn->function, 1, 0);
-    if ((char *)oldfn + RAW_ADDR_OFFSET == fdefn->raw_addr)
-        fdefn->raw_addr = (char *)fdefn->function + RAW_ADDR_OFFSET;
+    oldfn = fdefn->fun;
+    pscav(&fdefn->fun, 1, 0);
+    if ((char *)oldfn + FUN_RAW_ADDR_OFFSET == fdefn->raw_addr)
+        fdefn->raw_addr = (char *)fdefn->fun + FUN_RAW_ADDR_OFFSET;
 
     return result;
 }
 
-static lispobj ptrans_unboxed(lispobj thing, lispobj header)
+static lispobj
+ptrans_unboxed(lispobj thing, lispobj header)
 {
     int nwords;
     lispobj result, *new, *old;
-
+    
     nwords = 1 + HeaderValue(header);
-
+    
     /* Allocate it */
-    old = (lispobj *)PTR(thing);
+    old = (lispobj *)native_pointer(thing);
     new = read_only_free;
     read_only_free += CEILING(nwords, 2);
-
+    
     /* Copy it. */
     bcopy(old, new, nwords * sizeof(lispobj));
-
+    
     /* Deposit forwarding pointer. */
-    result = (lispobj)new | LowtagOf(thing);
+    result = make_lispobj(new , lowtag_of(thing));
     *old = result;
 
     return result;
 }
 
-static lispobj ptrans_vector(lispobj thing, int bits, int extra,
-                            boolean boxed, boolean constant)
+static lispobj
+ptrans_vector(lispobj thing, int bits, int extra,
+             boolean boxed, boolean constant)
 {
     struct vector *vector;
     int nwords;
     lispobj result, *new;
 
-    vector = (struct vector *)PTR(thing);
+    vector = (struct vector *)native_pointer(thing);
     nwords = 2 + (CEILING((fixnum_value(vector->length)+extra)*bits,32)>>5);
 
     if (boxed && !constant) {
@@ -670,7 +604,7 @@ static lispobj ptrans_vector(lispobj thing, int bits, int extra,
 
     bcopy(vector, new, nwords * sizeof(lispobj));
 
-    result = (lispobj)new | LowtagOf(thing);
+    result = make_lispobj(new, lowtag_of(thing));
     vector->header = result;
 
     if (boxed)
@@ -683,95 +617,94 @@ static lispobj ptrans_vector(lispobj thing, int bits, int extra,
 static void
 apply_code_fixups_during_purify(struct code *old_code, struct code *new_code)
 {
-  int nheader_words, ncode_words, nwords;
-  void  *constants_start_addr, *constants_end_addr;
-  void  *code_start_addr, *code_end_addr;
-  lispobj p;
-  lispobj fixups = NIL;
-  unsigned  displacement = (unsigned)new_code - (unsigned)old_code;
-  struct vector *fixups_vector;
-
-  /* Byte compiled code has no fixups. The trace table offset will be
-   * a fixnum if it's x86 compiled code - check. */
-  if (new_code->trace_table_offset & 0x3)
-    return;
-
-  /* Else it's x86 machine code. */
-  ncode_words = fixnum_value(new_code->code_size);
-  nheader_words = HeaderValue(*(lispobj *)new_code);
-  nwords = ncode_words + nheader_words;
-
-  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;
-
-  /* The first constant should be a pointer to the fixups for this
-   * 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 to a vector if it is valid. */
-  if ((fixups==0) || (fixups==type_UnboundMarker) || !Pointerp(fixups)) {
-#ifdef GENCGC
-    /* Check for a possible errors. */
-    sniff_code_object(new_code,displacement);
-#endif
-    return;
-  }
+    int nheader_words, ncode_words, nwords;
+    void  *constants_start_addr, *constants_end_addr;
+    void  *code_start_addr, *code_end_addr;
+    lispobj fixups = NIL;
+    unsigned  displacement = (unsigned)new_code - (unsigned)old_code;
+    struct vector *fixups_vector;
+
+    ncode_words = fixnum_value(new_code->code_size);
+    nheader_words = HeaderValue(*(lispobj *)new_code);
+    nwords = ncode_words + nheader_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;
+
+    /* The first constant should be a pointer to the fixups for this
+     * 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 to a vector if it is valid. */
+    if ((fixups==0) ||
+       (fixups==UNBOUND_MARKER_WIDETAG) ||
+       !is_lisp_pointer(fixups)) {
+#ifdef LISP_FEATURE_GENCGC
+       /* Check for a possible errors. */
+       sniff_code_object(new_code,displacement);
+#endif
+       return;
+    }
 
-  fixups_vector = (struct vector *)PTR(fixups);
+    fixups_vector = (struct vector *)native_pointer(fixups);
 
-  /* Could be pointing to a forwarding pointer. */
-  if (Pointerp(fixups) && (dynamic_pointer_p(fixups))
-      && forwarding_pointer_p(*(lispobj *)fixups_vector)) {
-    /* If so then follow it. */
-    fixups_vector = (struct vector *)PTR(*(lispobj *)fixups_vector);
-  }
+    /* Could be pointing to a forwarding pointer. */
+    if (is_lisp_pointer(fixups) && (dynamic_pointer_p(fixups))
+       && forwarding_pointer_p(*(lispobj *)fixups_vector)) {
+       /* If so then follow it. */
+       fixups_vector =
+           (struct vector *)native_pointer(*(lispobj *)fixups_vector);
+    }
 
-  if (TypeOf(fixups_vector->header) == type_SimpleArrayUnsignedByte32) {
-    /* We 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;
-    for (i=0; i<length; i++) {
-      unsigned offset = fixups_vector->data[i];
-      /* Now check the current value of offset. */
-      unsigned  old_value = *(unsigned *)((unsigned)code_start_addr + offset);
-
-      /* 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)))
-       /* So add the dispacement. */
-       *(unsigned *)((unsigned)code_start_addr + offset) = old_value
-         + displacement;
-      else
-       /* It is outside the old code object so it must be a relative
-        * fixup (absolute fixups are not saved). So subtract the
-        * displacement. */
-       *(unsigned *)((unsigned)code_start_addr + offset) = old_value
-         - displacement;
+    if (widetag_of(fixups_vector->header) ==
+       SIMPLE_ARRAY_UNSIGNED_BYTE_32_WIDETAG) {
+       /* We 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;
+       for (i=0; i<length; i++) {
+           unsigned offset = fixups_vector->data[i];
+           /* Now check the current value of offset. */
+           unsigned old_value =
+               *(unsigned *)((unsigned)code_start_addr + offset);
+
+           /* 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)))
+               /* So add the dispacement. */
+               *(unsigned *)((unsigned)code_start_addr + offset) = old_value
+                   + displacement;
+           else
+               /* It is outside the old code object so it must be a relative
+                * fixup (absolute fixups are not saved). So subtract the
+                * displacement. */
+               *(unsigned *)((unsigned)code_start_addr + offset) = old_value
+                   - displacement;
+       }
     }
-  }
 
-  /* No longer need the fixups. */
-  new_code->constants[0] = 0;
+    /* No longer need the fixups. */
+    new_code->constants[0] = 0;
 
-#ifdef GENCGC
-  /* Check for possible errors. */
-  sniff_code_object(new_code,displacement);
+#ifdef LISP_FEATURE_GENCGC
+    /* Check for possible errors. */
+    sniff_code_object(new_code,displacement);
 #endif
 }
 #endif
 
-static lispobj ptrans_code(lispobj thing)
+static lispobj
+ptrans_code(lispobj thing)
 {
     struct code *code, *new;
     int nwords;
     lispobj func, result;
 
-    code = (struct code *)PTR(thing);
+    code = (struct code *)native_pointer(thing);
     nwords = HeaderValue(code->header) + fixnum_value(code->code_size);
 
     new = (struct code *)read_only_free;
@@ -779,11 +712,11 @@ static lispobj ptrans_code(lispobj thing)
 
     bcopy(code, new, nwords * sizeof(lispobj));
 
-#ifdef __i386__
+#ifdef LISP_FEATURE_X86
     apply_code_fixups_during_purify(code,new);
 #endif
 
-    result = (lispobj)new | type_OtherPointer;
+    result = make_lispobj(new, OTHER_POINTER_LOWTAG);
 
     /* Stick in a forwarding pointer for the code object. */
     *(lispobj *)code = result;
@@ -791,17 +724,17 @@ static lispobj ptrans_code(lispobj thing)
     /* Put in forwarding pointers for all the functions. */
     for (func = code->entry_points;
          func != NIL;
-         func = ((struct function *)PTR(func))->next) {
+         func = ((struct simple_fun *)native_pointer(func))->next) {
 
-        gc_assert(LowtagOf(func) == type_FunctionPointer);
+        gc_assert(lowtag_of(func) == FUN_POINTER_LOWTAG);
 
-        *(lispobj *)PTR(func) = result + (func - thing);
+        *(lispobj *)native_pointer(func) = result + (func - thing);
     }
 
     /* Arrange to scavenge the debug info later. */
     pscav_later(&new->debug_info, 1);
 
-    if(new->trace_table_offset & 0x3)
+    if (new->trace_table_offset & 0x3)
 #if 0
       pscav(&new->trace_table_offset, 1, 0);
 #else
@@ -815,30 +748,32 @@ static lispobj ptrans_code(lispobj thing)
     pscav(&new->entry_points, 1, 1);
     for (func = new->entry_points;
          func != NIL;
-         func = ((struct function *)PTR(func))->next) {
-        gc_assert(LowtagOf(func) == type_FunctionPointer);
+         func = ((struct simple_fun *)native_pointer(func))->next) {
+        gc_assert(lowtag_of(func) == FUN_POINTER_LOWTAG);
         gc_assert(!dynamic_pointer_p(func));
 
 #ifdef __i386__
-       /* Temporarly convert the self pointer to a real function
-           pointer. */
-       ((struct function *)PTR(func))->self -= RAW_ADDR_OFFSET;
+       /* Temporarly convert the self pointer to a real function pointer. */
+       ((struct simple_fun *)native_pointer(func))->self
+           -= FUN_RAW_ADDR_OFFSET;
 #endif
-        pscav(&((struct function *)PTR(func))->self, 2, 1);
+        pscav(&((struct simple_fun *)native_pointer(func))->self, 2, 1);
 #ifdef __i386__
-       ((struct function *)PTR(func))->self += RAW_ADDR_OFFSET;
+       ((struct simple_fun *)native_pointer(func))->self
+           += FUN_RAW_ADDR_OFFSET;
 #endif
-        pscav_later(&((struct function *)PTR(func))->name, 3);
+        pscav_later(&((struct simple_fun *)native_pointer(func))->name, 3);
     }
 
     return result;
 }
 
-static lispobj ptrans_func(lispobj thing, lispobj header)
+static lispobj
+ptrans_func(lispobj thing, lispobj header)
 {
     int nwords;
     lispobj code, *new, *old, result;
-    struct function *function;
+    struct simple_fun *function;
 
     /* Thing can either be a function header, a closure function
      * header, a closure, or a funcallable-instance. If it's a closure
@@ -846,19 +781,22 @@ static lispobj ptrans_func(lispobj thing, lispobj header)
      * Otherwise we have to do something strange, 'cause it is buried
      * inside a code object. */
 
-    if (TypeOf(header) == type_FunctionHeader ||
-        TypeOf(header) == type_ClosureFunctionHeader) {
+    if (widetag_of(header) == SIMPLE_FUN_HEADER_WIDETAG ||
+        widetag_of(header) == CLOSURE_FUN_HEADER_WIDETAG) {
 
        /* We can only end up here if the code object has not been
          * scavenged, because if it had been scavenged, forwarding pointers
          * would have been left behind for all the entry points. */
 
-        function = (struct function *)PTR(thing);
-        code = (PTR(thing)-(HeaderValue(function->header)*sizeof(lispobj))) |
-            type_OtherPointer;
-
+        function = (struct simple_fun *)native_pointer(thing);
+        code =
+           make_lispobj
+           ((native_pointer(thing) -
+             (HeaderValue(function->header))), OTHER_POINTER_LOWTAG);
+       
         /* This will cause the function's header to be replaced with a 
          * forwarding pointer. */
+
         ptrans_code(code);
 
         /* So we can just return that. */
@@ -867,10 +805,10 @@ static lispobj ptrans_func(lispobj thing, lispobj header)
     else {
        /* It's some kind of closure-like thing. */
         nwords = 1 + HeaderValue(header);
-        old = (lispobj *)PTR(thing);
+        old = (lispobj *)native_pointer(thing);
 
        /* Allocate the new one. */
-       if (TypeOf(header) == type_FuncallableInstanceHeader) {
+       if (widetag_of(header) == FUNCALLABLE_INSTANCE_HEADER_WIDETAG) {
            /* FINs *must* not go in read_only space. */
            new = static_free;
            static_free += CEILING(nwords, 2);
@@ -886,7 +824,7 @@ static lispobj ptrans_func(lispobj thing, lispobj header)
         bcopy(old, new, nwords * sizeof(lispobj));
 
         /* Deposit forwarding pointer. */
-        result = (lispobj)new | LowtagOf(thing);
+        result = make_lispobj(new, lowtag_of(thing));
         *old = result;
 
         /* Scavenge it. */
@@ -896,7 +834,8 @@ static lispobj ptrans_func(lispobj thing, lispobj header)
     }
 }
 
-static lispobj ptrans_returnpc(lispobj thing, lispobj header)
+static lispobj
+ptrans_returnpc(lispobj thing, lispobj header)
 {
     lispobj code, new;
 
@@ -904,7 +843,7 @@ static lispobj ptrans_returnpc(lispobj thing, lispobj header)
     code = thing - HeaderValue(header)*sizeof(lispobj);
 
     /* Make sure it's been transported. */
-    new = *(lispobj *)PTR(code);
+    new = *(lispobj *)native_pointer(code);
     if (!forwarding_pointer_p(new))
         new = ptrans_code(code);
 
@@ -914,7 +853,8 @@ static lispobj ptrans_returnpc(lispobj thing, lispobj header)
 
 #define WORDS_PER_CONS CEILING(sizeof(struct cons) / sizeof(lispobj), 2)
 
-static lispobj ptrans_list(lispobj thing, boolean constant)
+static lispobj
+ptrans_list(lispobj thing, boolean constant)
 {
     struct cons *old, *new, *orig;
     int length;
@@ -927,7 +867,7 @@ static lispobj ptrans_list(lispobj thing, boolean constant)
 
     do {
         /* Allocate a new cons cell. */
-        old = (struct cons *)PTR(thing);
+        old = (struct cons *)native_pointer(thing);
         if (constant) {
             new = (struct cons *)read_only_free;
             read_only_free += WORDS_PER_CONS;
@@ -942,100 +882,101 @@ static lispobj ptrans_list(lispobj thing, boolean constant)
         thing = new->cdr = old->cdr;
 
         /* Set up the forwarding pointer. */
-        *(lispobj *)old = ((lispobj)new) | type_ListPointer;
+        *(lispobj *)old = make_lispobj(new, LIST_POINTER_LOWTAG);
 
         /* And count this cell. */
         length++;
-    } while (LowtagOf(thing) == type_ListPointer &&
+    } while (lowtag_of(thing) == LIST_POINTER_LOWTAG &&
              dynamic_pointer_p(thing) &&
-             !(forwarding_pointer_p(*(lispobj *)PTR(thing))));
+             !(forwarding_pointer_p(*(lispobj *)native_pointer(thing))));
 
     /* Scavenge the list we just copied. */
     pscav((lispobj *)orig, length * WORDS_PER_CONS, constant);
 
-    return ((lispobj)orig) | type_ListPointer;
+    return make_lispobj(orig, LIST_POINTER_LOWTAG);
 }
 
-static lispobj ptrans_otherptr(lispobj thing, lispobj header, boolean constant)
+static lispobj
+ptrans_otherptr(lispobj thing, lispobj header, boolean constant)
 {
-    switch (TypeOf(header)) {
-      case type_Bignum:
-      case type_SingleFloat:
-      case type_DoubleFloat:
-#ifdef type_LongFloat
-      case type_LongFloat:
+    switch (widetag_of(header)) {
+      case BIGNUM_WIDETAG:
+      case SINGLE_FLOAT_WIDETAG:
+      case DOUBLE_FLOAT_WIDETAG:
+#ifdef LONG_FLOAT_WIDETAG
+      case LONG_FLOAT_WIDETAG:
 #endif
-#ifdef type_ComplexSingleFloat
-      case type_ComplexSingleFloat:
+#ifdef COMPLEX_SINGLE_FLOAT_WIDETAG
+      case COMPLEX_SINGLE_FLOAT_WIDETAG:
 #endif
-#ifdef type_ComplexDoubleFloat
-      case type_ComplexDoubleFloat:
+#ifdef COMPLEX_DOUBLE_FLOAT_WIDETAG
+      case COMPLEX_DOUBLE_FLOAT_WIDETAG:
 #endif
-#ifdef type_ComplexLongFloat
-      case type_ComplexLongFloat:
+#ifdef COMPLEX_LONG_FLOAT_WIDETAG
+      case COMPLEX_LONG_FLOAT_WIDETAG:
 #endif
-      case type_Sap:
+      case SAP_WIDETAG:
         return ptrans_unboxed(thing, header);
 
-      case type_Ratio:
-      case type_Complex:
-      case type_SimpleArray:
-      case type_ComplexString:
-      case type_ComplexVector:
-      case type_ComplexArray:
+      case RATIO_WIDETAG:
+      case COMPLEX_WIDETAG:
+      case SIMPLE_ARRAY_WIDETAG:
+      case COMPLEX_STRING_WIDETAG:
+      case COMPLEX_VECTOR_WIDETAG:
+      case COMPLEX_ARRAY_WIDETAG:
         return ptrans_boxed(thing, header, constant);
        
-      case type_ValueCellHeader:
-      case type_WeakPointer:
+      case VALUE_CELL_HEADER_WIDETAG:
+      case WEAK_POINTER_WIDETAG:
         return ptrans_boxed(thing, header, 0);
 
-      case type_SymbolHeader:
+      case SYMBOL_HEADER_WIDETAG:
         return ptrans_boxed(thing, header, 0);
 
-      case type_SimpleString:
+      case SIMPLE_STRING_WIDETAG:
         return ptrans_vector(thing, 8, 1, 0, constant);
 
-      case type_SimpleBitVector:
+      case SIMPLE_BIT_VECTOR_WIDETAG:
         return ptrans_vector(thing, 1, 0, 0, constant);
 
-      case type_SimpleVector:
+      case SIMPLE_VECTOR_WIDETAG:
         return ptrans_vector(thing, 32, 0, 1, constant);
 
-      case type_SimpleArrayUnsignedByte2:
+      case SIMPLE_ARRAY_UNSIGNED_BYTE_2_WIDETAG:
         return ptrans_vector(thing, 2, 0, 0, constant);
 
-      case type_SimpleArrayUnsignedByte4:
+      case SIMPLE_ARRAY_UNSIGNED_BYTE_4_WIDETAG:
         return ptrans_vector(thing, 4, 0, 0, constant);
 
-      case type_SimpleArrayUnsignedByte8:
-#ifdef type_SimpleArraySignedByte8
-      case type_SimpleArraySignedByte8:
+      case SIMPLE_ARRAY_UNSIGNED_BYTE_8_WIDETAG:
+#ifdef SIMPLE_ARRAY_SIGNED_BYTE_8_WIDETAG
+      case SIMPLE_ARRAY_SIGNED_BYTE_8_WIDETAG:
 #endif
         return ptrans_vector(thing, 8, 0, 0, constant);
 
-      case type_SimpleArrayUnsignedByte16:
-#ifdef type_SimpleArraySignedByte16
-      case type_SimpleArraySignedByte16:
+      case SIMPLE_ARRAY_UNSIGNED_BYTE_16_WIDETAG:
+#ifdef SIMPLE_ARRAY_SIGNED_BYTE_16_WIDETAG
+      case SIMPLE_ARRAY_SIGNED_BYTE_16_WIDETAG:
 #endif
         return ptrans_vector(thing, 16, 0, 0, constant);
 
-      case type_SimpleArrayUnsignedByte32:
-#ifdef type_SimpleArraySignedByte30
-      case type_SimpleArraySignedByte30:
+      case SIMPLE_ARRAY_UNSIGNED_BYTE_32_WIDETAG:
+#ifdef SIMPLE_ARRAY_SIGNED_BYTE_30_WIDETAG
+      case SIMPLE_ARRAY_SIGNED_BYTE_30_WIDETAG:
 #endif
-#ifdef type_SimpleArraySignedByte32
-      case type_SimpleArraySignedByte32:
+#ifdef SIMPLE_ARRAY_SIGNED_BYTE_32_WIDETAG
+      case SIMPLE_ARRAY_SIGNED_BYTE_32_WIDETAG:
 #endif
         return ptrans_vector(thing, 32, 0, 0, constant);
 
-      case type_SimpleArraySingleFloat:
+      case SIMPLE_ARRAY_SINGLE_FLOAT_WIDETAG:
         return ptrans_vector(thing, 32, 0, 0, constant);
 
-      case type_SimpleArrayDoubleFloat:
+      case SIMPLE_ARRAY_DOUBLE_FLOAT_WIDETAG:
         return ptrans_vector(thing, 64, 0, 0, constant);
 
-#ifdef type_SimpleArrayLongFloat
-      case type_SimpleArrayLongFloat:
+#ifdef SIMPLE_ARRAY_LONG_FLOAT_WIDETAG
+      case SIMPLE_ARRAY_LONG_FLOAT_WIDETAG:
 #ifdef __i386__
         return ptrans_vector(thing, 96, 0, 0, constant);
 #endif
@@ -1044,18 +985,18 @@ static lispobj ptrans_otherptr(lispobj thing, lispobj header, boolean constant)
 #endif
 #endif
 
-#ifdef type_SimpleArrayComplexSingleFloat
-      case type_SimpleArrayComplexSingleFloat:
+#ifdef SIMPLE_ARRAY_COMPLEX_SINGLE_FLOAT_WIDETAG
+      case SIMPLE_ARRAY_COMPLEX_SINGLE_FLOAT_WIDETAG:
         return ptrans_vector(thing, 64, 0, 0, constant);
 #endif
 
-#ifdef type_SimpleArrayComplexDoubleFloat
-      case type_SimpleArrayComplexDoubleFloat:
+#ifdef SIMPLE_ARRAY_COMPLEX_DOUBLE_FLOAT_WIDETAG
+      case SIMPLE_ARRAY_COMPLEX_DOUBLE_FLOAT_WIDETAG:
         return ptrans_vector(thing, 128, 0, 0, constant);
 #endif
 
-#ifdef type_SimpleArrayComplexLongFloat
-      case type_SimpleArrayComplexLongFloat:
+#ifdef SIMPLE_ARRAY_COMPLEX_LONG_FLOAT_WIDETAG
+      case SIMPLE_ARRAY_COMPLEX_LONG_FLOAT_WIDETAG:
 #ifdef __i386__
         return ptrans_vector(thing, 192, 0, 0, constant);
 #endif
@@ -1064,13 +1005,13 @@ static lispobj ptrans_otherptr(lispobj thing, lispobj header, boolean constant)
 #endif
 #endif
 
-      case type_CodeHeader:
+      case CODE_HEADER_WIDETAG:
         return ptrans_code(thing);
 
-      case type_ReturnPcHeader:
+      case RETURN_PC_HEADER_WIDETAG:
         return ptrans_returnpc(thing, header);
 
-      case type_Fdefn:
+      case FDEFN_WIDETAG:
        return ptrans_fdefn(thing, header);
 
       default:
@@ -1080,15 +1021,16 @@ static lispobj ptrans_otherptr(lispobj thing, lispobj header, boolean constant)
     }
 }
 
-static int pscav_fdefn(struct fdefn *fdefn)
+static int
+pscav_fdefn(struct fdefn *fdefn)
 {
     boolean fix_func;
 
-    fix_func = ((char *)(fdefn->function+RAW_ADDR_OFFSET) == fdefn->raw_addr);
+    fix_func = ((char *)(fdefn->fun+FUN_RAW_ADDR_OFFSET) == fdefn->raw_addr);
     pscav(&fdefn->name, 1, 1);
-    pscav(&fdefn->function, 1, 0);
+    pscav(&fdefn->fun, 1, 0);
     if (fix_func)
-        fdefn->raw_addr = (char *)(fdefn->function + RAW_ADDR_OFFSET);
+        fdefn->raw_addr = (char *)(fdefn->fun + FUN_RAW_ADDR_OFFSET);
     return sizeof(struct fdefn) / sizeof(lispobj);
 }
 
@@ -1101,19 +1043,6 @@ pscav_code(struct code*code)
     lispobj func;
     nwords = HeaderValue(code->header) + fixnum_value(code->code_size);
 
-    /* pw--The trace_table_offset slot can contain a list pointer. This
-     * occurs when the code object is a top level form that initializes
-     * a byte-compiled function. The fact that PURIFY was ignoring this
-     * slot may be a bug unrelated to the x86 port, except that TLF's
-     * normally become unreachable after the loader calls them and
-     * won't be seen by PURIFY at all!! */
-    if(code->trace_table_offset & 0x3)
-#if 0
-      pscav(&code->trace_table_offset, 1, 0);
-#else
-      code->trace_table_offset = NIL; /* limit lifetime */
-#endif
-
     /* Arrange to scavenge the debug info later. */
     pscav_later(&code->debug_info, 1);
 
@@ -1124,59 +1053,62 @@ pscav_code(struct code*code)
     pscav(&code->entry_points, 1, 1);
     for (func = code->entry_points;
          func != NIL;
-         func = ((struct function *)PTR(func))->next) {
-        gc_assert(LowtagOf(func) == type_FunctionPointer);
+         func = ((struct simple_fun *)native_pointer(func))->next) {
+        gc_assert(lowtag_of(func) == FUN_POINTER_LOWTAG);
         gc_assert(!dynamic_pointer_p(func));
 
 #ifdef __i386__
-       /* Temporarly convert the self pointer to a real function
+       /* Temporarily convert the self pointer to a real function
         * pointer. */
-       ((struct function *)PTR(func))->self -= RAW_ADDR_OFFSET;
+       ((struct simple_fun *)native_pointer(func))->self
+           -= FUN_RAW_ADDR_OFFSET;
 #endif
-        pscav(&((struct function *)PTR(func))->self, 2, 1);
+        pscav(&((struct simple_fun *)native_pointer(func))->self, 2, 1);
 #ifdef __i386__
-       ((struct function *)PTR(func))->self += RAW_ADDR_OFFSET;
+       ((struct simple_fun *)native_pointer(func))->self
+           += FUN_RAW_ADDR_OFFSET;
 #endif
-        pscav_later(&((struct function *)PTR(func))->name, 3);
+        pscav_later(&((struct simple_fun *)native_pointer(func))->name, 3);
     }
 
     return CEILING(nwords,2);
 }
 #endif
 
-static lispobj *pscav(lispobj *addr, int nwords, boolean constant)
+static lispobj *
+pscav(lispobj *addr, int nwords, boolean constant)
 {
     lispobj thing, *thingp, header;
-    int count;
+    int count = 0; /* (0 = dummy init value to stop GCC warning) */
     struct vector *vector;
 
     while (nwords > 0) {
         thing = *addr;
-        if (Pointerp(thing)) {
+        if (is_lisp_pointer(thing)) {
             /* It's a pointer. Is it something we might have to move? */
             if (dynamic_pointer_p(thing)) {
                 /* Maybe. Have we already moved it? */
-               thingp = (lispobj *)PTR(thing);
+               thingp = (lispobj *)native_pointer(thing);
                 header = *thingp;
-                if (Pointerp(header) && forwarding_pointer_p(header))
+                if (is_lisp_pointer(header) && forwarding_pointer_p(header))
                     /* Yep, so just copy the forwarding pointer. */
                     thing = header;
                 else {
                     /* Nope, copy the object. */
-                    switch (LowtagOf(thing)) {
-                      case type_FunctionPointer:
+                    switch (lowtag_of(thing)) {
+                      case FUN_POINTER_LOWTAG:
                         thing = ptrans_func(thing, header);
                         break;
 
-                      case type_ListPointer:
+                      case LIST_POINTER_LOWTAG:
                         thing = ptrans_list(thing, constant);
                         break;
 
-                      case type_InstancePointer:
+                      case INSTANCE_POINTER_LOWTAG:
                         thing = ptrans_instance(thing, header, constant);
                         break;
 
-                      case type_OtherPointer:
+                      case OTHER_POINTER_LOWTAG:
                         thing = ptrans_otherptr(thing, header, constant);
                         break;
 
@@ -1192,87 +1124,88 @@ static lispobj *pscav(lispobj *addr, int nwords, boolean constant)
         else if (thing & 3) {
             /* It's an other immediate. Maybe the header for an unboxed */
             /* object. */
-            switch (TypeOf(thing)) {
-              case type_Bignum:
-              case type_SingleFloat:
-              case type_DoubleFloat:
-#ifdef type_LongFloat
-              case type_LongFloat:
-#endif
-              case type_Sap:
+            switch (widetag_of(thing)) {
+              case BIGNUM_WIDETAG:
+              case SINGLE_FLOAT_WIDETAG:
+              case DOUBLE_FLOAT_WIDETAG:
+#ifdef LONG_FLOAT_WIDETAG
+              case LONG_FLOAT_WIDETAG:
+#endif
+              case SAP_WIDETAG:
                 /* It's an unboxed simple object. */
                 count = HeaderValue(thing)+1;
                 break;
 
-              case type_SimpleVector:
-                if (HeaderValue(thing) == subtype_VectorValidHashing)
-                    *addr = (subtype_VectorMustRehash<<type_Bits) |
-                        type_SimpleVector;
+              case SIMPLE_VECTOR_WIDETAG:
+                 if (HeaderValue(thing) == subtype_VectorValidHashing) {
+                    *addr = (subtype_VectorMustRehash << N_WIDETAG_BITS) |
+                        SIMPLE_VECTOR_WIDETAG;
+                 }
                 count = 1;
                 break;
 
-              case type_SimpleString:
+              case SIMPLE_STRING_WIDETAG:
                 vector = (struct vector *)addr;
                 count = CEILING(NWORDS(fixnum_value(vector->length)+1,4)+2,2);
                 break;
 
-              case type_SimpleBitVector:
+              case SIMPLE_BIT_VECTOR_WIDETAG:
                 vector = (struct vector *)addr;
                 count = CEILING(NWORDS(fixnum_value(vector->length),32)+2,2);
                 break;
 
-              case type_SimpleArrayUnsignedByte2:
+              case SIMPLE_ARRAY_UNSIGNED_BYTE_2_WIDETAG:
                 vector = (struct vector *)addr;
                 count = CEILING(NWORDS(fixnum_value(vector->length),16)+2,2);
                 break;
 
-              case type_SimpleArrayUnsignedByte4:
+              case SIMPLE_ARRAY_UNSIGNED_BYTE_4_WIDETAG:
                 vector = (struct vector *)addr;
                 count = CEILING(NWORDS(fixnum_value(vector->length),8)+2,2);
                 break;
 
-              case type_SimpleArrayUnsignedByte8:
-#ifdef type_SimpleArraySignedByte8
-              case type_SimpleArraySignedByte8:
+              case SIMPLE_ARRAY_UNSIGNED_BYTE_8_WIDETAG:
+#ifdef SIMPLE_ARRAY_SIGNED_BYTE_8_WIDETAG
+              case SIMPLE_ARRAY_SIGNED_BYTE_8_WIDETAG:
 #endif
                 vector = (struct vector *)addr;
                 count = CEILING(NWORDS(fixnum_value(vector->length),4)+2,2);
                 break;
 
-              case type_SimpleArrayUnsignedByte16:
-#ifdef type_SimpleArraySignedByte16
-              case type_SimpleArraySignedByte16:
+              case SIMPLE_ARRAY_UNSIGNED_BYTE_16_WIDETAG:
+#ifdef SIMPLE_ARRAY_SIGNED_BYTE_16_WIDETAG
+              case SIMPLE_ARRAY_SIGNED_BYTE_16_WIDETAG:
 #endif
                 vector = (struct vector *)addr;
                 count = CEILING(NWORDS(fixnum_value(vector->length),2)+2,2);
                 break;
 
-              case type_SimpleArrayUnsignedByte32:
-#ifdef type_SimpleArraySignedByte30
-              case type_SimpleArraySignedByte30:
+              case SIMPLE_ARRAY_UNSIGNED_BYTE_32_WIDETAG:
+#ifdef SIMPLE_ARRAY_SIGNED_BYTE_30_WIDETAG
+              case SIMPLE_ARRAY_SIGNED_BYTE_30_WIDETAG:
 #endif
-#ifdef type_SimpleArraySignedByte32
-              case type_SimpleArraySignedByte32:
+#ifdef SIMPLE_ARRAY_SIGNED_BYTE_32_WIDETAG
+              case SIMPLE_ARRAY_SIGNED_BYTE_32_WIDETAG:
 #endif
                 vector = (struct vector *)addr;
                 count = CEILING(fixnum_value(vector->length)+2,2);
                 break;
 
-              case type_SimpleArraySingleFloat:
+              case SIMPLE_ARRAY_SINGLE_FLOAT_WIDETAG:
                 vector = (struct vector *)addr;
                 count = CEILING(fixnum_value(vector->length)+2,2);
                 break;
 
-              case type_SimpleArrayDoubleFloat:
-#ifdef type_SimpleArrayComplexSingleFloat
-              case type_SimpleArrayComplexSingleFloat:
+              case SIMPLE_ARRAY_DOUBLE_FLOAT_WIDETAG:
+#ifdef SIMPLE_ARRAY_COMPLEX_SINGLE_FLOAT_WIDETAG
+              case SIMPLE_ARRAY_COMPLEX_SINGLE_FLOAT_WIDETAG:
 #endif
                 vector = (struct vector *)addr;
                 count = fixnum_value(vector->length)*2+2;
                 break;
 
-#ifdef type_SimpleArrayLongFloat
-              case type_SimpleArrayLongFloat:
+#ifdef SIMPLE_ARRAY_LONG_FLOAT_WIDETAG
+              case SIMPLE_ARRAY_LONG_FLOAT_WIDETAG:
                 vector = (struct vector *)addr;
 #ifdef __i386__
                 count = fixnum_value(vector->length)*3+2;
@@ -1283,15 +1216,15 @@ static lispobj *pscav(lispobj *addr, int nwords, boolean constant)
                 break;
 #endif
 
-#ifdef type_SimpleArrayComplexDoubleFloat
-              case type_SimpleArrayComplexDoubleFloat:
+#ifdef SIMPLE_ARRAY_COMPLEX_DOUBLE_FLOAT_WIDETAG
+              case SIMPLE_ARRAY_COMPLEX_DOUBLE_FLOAT_WIDETAG:
                 vector = (struct vector *)addr;
                 count = fixnum_value(vector->length)*4+2;
                 break;
 #endif
 
-#ifdef type_SimpleArrayComplexLongFloat
-              case type_SimpleArrayComplexLongFloat:
+#ifdef SIMPLE_ARRAY_COMPLEX_LONG_FLOAT_WIDETAG
+              case SIMPLE_ARRAY_COMPLEX_LONG_FLOAT_WIDETAG:
                 vector = (struct vector *)addr;
 #ifdef __i386__
                 count = fixnum_value(vector->length)*6+2;
@@ -1302,7 +1235,7 @@ static lispobj *pscav(lispobj *addr, int nwords, boolean constant)
                 break;
 #endif
 
-              case type_CodeHeader:
+              case CODE_HEADER_WIDETAG:
 #ifndef __i386__
                 gc_abort(); /* no code headers in static space */
 #else
@@ -1310,39 +1243,37 @@ static lispobj *pscav(lispobj *addr, int nwords, boolean constant)
 #endif
                 break;
 
-              case type_FunctionHeader:
-              case type_ClosureFunctionHeader:
-              case type_ReturnPcHeader:
+              case SIMPLE_FUN_HEADER_WIDETAG:
+              case CLOSURE_FUN_HEADER_WIDETAG:
+              case RETURN_PC_HEADER_WIDETAG:
                 /* We should never hit any of these, 'cause they occur
                  * buried in the middle of code objects. */
                 gc_abort();
                break;
 
 #ifdef __i386__
-             case type_ClosureHeader:
-             case type_FuncallableInstanceHeader:
-             case type_ByteCodeFunction:
-             case type_ByteCodeClosure:
+             case CLOSURE_HEADER_WIDETAG:
+             case FUNCALLABLE_INSTANCE_HEADER_WIDETAG:
                /* The function self pointer needs special care on the
                 * x86 because it is the real entry point. */
                {
-                 lispobj fun = ((struct closure *)addr)->function
-                   - RAW_ADDR_OFFSET;
+                 lispobj fun = ((struct closure *)addr)->fun
+                   - FUN_RAW_ADDR_OFFSET;
                  pscav(&fun, 1, constant);
-                 ((struct closure *)addr)->function = fun + RAW_ADDR_OFFSET;
+                 ((struct closure *)addr)->fun = fun + FUN_RAW_ADDR_OFFSET;
                }
                count = 2;
                break;
 #endif
 
-              case type_WeakPointer:
+              case WEAK_POINTER_WIDETAG:
                 /* Weak pointers get preserved during purify, 'cause I
                 * don't feel like figuring out how to break them. */
                 pscav(addr+1, 2, constant);
                 count = 4;
                 break;
 
-             case type_Fdefn:
+             case FDEFN_WIDETAG:
                /* We have to handle fdefn objects specially, so we
                 * can fix up the raw function address. */
                count = pscav_fdefn((struct fdefn *)addr);
@@ -1365,18 +1296,23 @@ static lispobj *pscav(lispobj *addr, int nwords, boolean constant)
     return addr;
 }
 
-int purify(lispobj static_roots, lispobj read_only_roots)
+int
+purify(lispobj static_roots, lispobj read_only_roots)
 {
     lispobj *clean;
     int count, i;
     struct later *laters, *next;
+    struct thread *thread;
 
 #ifdef PRINTNOISE
     printf("[doing purification:");
     fflush(stdout);
 #endif
-
-    if (fixnum_value(SymbolValue(FREE_INTERRUPT_CONTEXT_INDEX)) != 0) {
+#ifdef LISP_FEATURE_GENCGC
+    gc_alloc_update_all_page_tables();
+#endif
+    for_each_thread(thread)
+       if (fixnum_value(SymbolValue(FREE_INTERRUPT_CONTEXT_INDEX,thread)) != 0) {
        /* FIXME: 1. What does this mean? 2. It shouldn't be reporting
         * its error simply by a. printing a string b. to stdout instead
         * of stderr. */
@@ -1385,24 +1321,41 @@ int purify(lispobj static_roots, lispobj read_only_roots)
         return 0;
     }
 
-#if defined(ibmrt) || defined(__i386__)
+#if defined(__i386__)
     dynamic_space_free_pointer =
-      (lispobj*)SymbolValue(ALLOCATION_POINTER);
+      (lispobj*)SymbolValue(ALLOCATION_POINTER,0);
 #endif
 
     read_only_end = read_only_free =
-        (lispobj *)SymbolValue(READ_ONLY_SPACE_FREE_POINTER);
+        (lispobj *)SymbolValue(READ_ONLY_SPACE_FREE_POINTER,0);
     static_end = static_free =
-        (lispobj *)SymbolValue(STATIC_SPACE_FREE_POINTER);
+        (lispobj *)SymbolValue(STATIC_SPACE_FREE_POINTER,0);
 
 #ifdef PRINTNOISE
     printf(" roots");
     fflush(stdout);
 #endif
 
-#ifdef GENCGC
-    gc_assert((lispobj *)CONTROL_STACK_END > ((&read_only_roots)+1));
-    setup_i386_stack_scav(((&static_roots)-2), (lispobj *)CONTROL_STACK_END);
+#if (defined(LISP_FEATURE_GENCGC) && defined(LISP_FEATURE_X86))
+#if 0
+    /* This is what we should do, but can't unless the threads in
+     * question are suspended with ptrace.  That's right, purify is not
+     * threadsafe
+     */
+    for_each_thread(thread) {
+       void **ptr;
+       struct user_regs_struct regs;
+       if(ptrace(PTRACE_GETREGS,thread->pid,0,&regs)){
+           fprintf(stderr,"child pid %d, %s\n",thread->pid,strerror(errno));
+           lose("PTRACE_GETREGS");
+       }
+       setup_i386_stack_scav(regs.ebp,
+                             ((void *)thread->control_stack_end));
+    }
+#endif /* 0 */
+    /* stopgap until we can set things up as in preceding comment */
+    setup_i386_stack_scav(((&static_roots)-2),
+                         ((void *)all_threads->control_stack_end));
 #endif
 
     pscav(&static_roots, 1, 0);
@@ -1412,8 +1365,9 @@ int purify(lispobj static_roots, lispobj read_only_roots)
     printf(" handlers");
     fflush(stdout);
 #endif
-    pscav((lispobj *) interrupt_handlers,
-          sizeof(interrupt_handlers) / sizeof(lispobj),
+    pscav((lispobj *) all_threads->interrupt_data->interrupt_handlers,
+          sizeof(all_threads->interrupt_data->interrupt_handlers)
+         / sizeof(lispobj),
           0);
 
 #ifdef PRINTNOISE
@@ -1421,37 +1375,49 @@ int purify(lispobj static_roots, lispobj read_only_roots)
     fflush(stdout);
 #endif
 #ifndef __i386__
-    pscav((lispobj *)control_stack,
-         current_control_stack_pointer - (lispobj *)CONTROL_STACK_START,
+    pscav((lispobj *)all_threads->control_stack_start,
+         current_control_stack_pointer - 
+         all_threads->control_stack_start,
          0);
 #else
-#ifdef GENCGC
+#ifdef LISP_FEATURE_GENCGC
     pscav_i386_stack();
 #endif
-#ifdef WANT_CGC
-    gc_assert((lispobj *)control_stack_end > ((&read_only_roots)+1));
-    carefully_pscav_stack(((&read_only_roots)+1),
-                         (lispobj *)CONTROL_STACK_END);
-#endif
 #endif
 
 #ifdef PRINTNOISE
     printf(" bindings");
     fflush(stdout);
 #endif
-#if !defined(ibmrt) && !defined(__i386__)
-    pscav(BINDING_STACK_START,
-         current_binding_stack_pointer - (lispobj *)BINDING_STACK_START,
+#if !defined(__i386__)
+    pscav( (lispobj *)all_threads->binding_stack_start,
+         (lispobj *)current_binding_stack_pointer -
+          all_threads->binding_stack_start,
          0);
 #else
-    pscav(BINDING_STACK_START,
-         (lispobj *)SymbolValue(BINDING_STACK_POINTER) -
-         (lispobj *)BINDING_STACK_START,
+    for_each_thread(thread) {
+       pscav( (lispobj *)thread->binding_stack_start,
+              (lispobj *)SymbolValue(BINDING_STACK_POINTER,thread) -
+              (lispobj *)thread->binding_stack_start,
+         0);
+       pscav( (lispobj *) (thread+1),
+              fixnum_value(SymbolValue(FREE_TLS_INDEX,0)) -
+              (sizeof (struct thread))/(sizeof (lispobj)),
          0);
+    }
+
+
 #endif
 
-#ifdef SCAVENGE_READ_ONLY_SPACE
-    if (SymbolValue(SCAVENGE_READ_ONLY_SPACE) != type_UnboundMarker
+    /* The original CMU CL code had scavenge-read-only-space code
+     * controlled by the Lisp-level variable
+     * *SCAVENGE-READ-ONLY-SPACE*. It was disabled by default, and it
+     * wasn't documented under what circumstances it was useful or
+     * safe to turn it on, so it's been turned off in SBCL. If you
+     * want/need this functionality, and can test and document it,
+     * please submit a patch. */
+#if 0
+    if (SymbolValue(SCAVENGE_READ_ONLY_SPACE) != UNBOUND_MARKER_WIDETAG
        && SymbolValue(SCAVENGE_READ_ONLY_SPACE) != NIL) {
       unsigned  read_only_space_size =
          (lispobj *)SymbolValue(READ_ONLY_SPACE_FREE_POINTER) -
@@ -1459,7 +1425,7 @@ int purify(lispobj static_roots, lispobj read_only_roots)
       fprintf(stderr,
              "scavenging read only space: %d bytes\n",
              read_only_space_size * sizeof(lispobj));
-      pscav(READ_ONLY_SPACE_START, read_only_space_size, 0);
+      pscav( (lispobj *)READ_ONLY_SPACE_START, read_only_space_size, 0);
     }
 #endif
 
@@ -1498,64 +1464,31 @@ int purify(lispobj static_roots, lispobj read_only_roots)
     fflush(stdout);
 #endif
 
-#if defined(WANT_CGC) && defined(X86_CGC_ACTIVE_P)
-    if(SymbolValue(X86_CGC_ACTIVE_P) != T) {
-       os_zero((os_vm_address_t) DYNAMIC_SPACE_START,
-               (os_vm_size_t) DYNAMIC_SPACE_SIZE);
-    }
-#else
-    os_zero((os_vm_address_t) DYNAMIC_SPACE_START,
+    os_zero((os_vm_address_t) current_dynamic_space,
             (os_vm_size_t) DYNAMIC_SPACE_SIZE);
-#endif
 
     /* Zero the stack. Note that the stack is also zeroed by SUB-GC
      * calling SCRUB-CONTROL-STACK - this zeros the stack on the x86. */
 #ifndef __i386__
     os_zero((os_vm_address_t) current_control_stack_pointer,
-            (os_vm_size_t) (CONTROL_STACK_SIZE -
-                            ((current_control_stack_pointer -
-                             (lispobj *)CONTROL_STACK_START) *
-                             sizeof(lispobj))));
-#endif
-
-#if defined(WANT_CGC) && defined(STATIC_BLUE_BAG)
-    {
-      lispobj bag = SymbolValue(STATIC_BLUE_BAG);
-      struct cons*cons = (struct cons*)static_free;
-      struct cons*pair = cons + 1;
-      static_free += 2*WORDS_PER_CONS;
-      if(bag == type_UnboundMarker)
-       bag = NIL;
-      cons->cdr = bag;
-      cons->car = (lispobj)pair | type_ListPointer;
-      pair->car = (lispobj)static_end;
-      pair->cdr = (lispobj)static_free;
-      bag = (lispobj)cons | type_ListPointer;
-      SetSymbolValue(STATIC_BLUE_BAG, bag);
-    }
+            (os_vm_size_t)
+           ((all_threads->control_stack_end -
+             current_control_stack_pointer) * sizeof(lispobj)));
 #endif
 
     /* It helps to update the heap free pointers so that free_heap can
      * verify after it's done. */
-    SetSymbolValue(READ_ONLY_SPACE_FREE_POINTER, (lispobj)read_only_free);
-    SetSymbolValue(STATIC_SPACE_FREE_POINTER, (lispobj)static_free);
+    SetSymbolValue(READ_ONLY_SPACE_FREE_POINTER, (lispobj)read_only_free,0);
+    SetSymbolValue(STATIC_SPACE_FREE_POINTER, (lispobj)static_free,0);
 
-#if !defined(ibmrt) && !defined(__i386__)
-    dynamic_space_free_pointer = DYNAMIC_SPACE_START;
-#else
-#if defined(WANT_CGC) && defined(X86_CGC_ACTIVE_P)
-    /* X86 using CGC */
-    if(SymbolValue(X86_CGC_ACTIVE_P) != T)
-       SetSymbolValue(ALLOCATION_POINTER, (lispobj)DYNAMIC_SPACE_START);
-    else
-       cgc_free_heap();
+#if !defined(__i386__)
+    dynamic_space_free_pointer = current_dynamic_space;
+    set_auto_gc_trigger(bytes_consed_between_gcs);
 #else
-#if defined GENCGC
+#if defined LISP_FEATURE_GENCGC
     gc_free_heap();
 #else
-    /* ibmrt using GC */
-    SetSymbolValue(ALLOCATION_POINTER, (lispobj)DYNAMIC_SPACE_START);
-#endif
+#error unsupported case /* in CMU CL, was "ibmrt using GC" */
 #endif
 #endif
 
@@ -1563,6 +1496,5 @@ int purify(lispobj static_roots, lispobj read_only_roots)
     printf(" done]\n");
     fflush(stdout);
 #endif
-
     return 0;
 }