(ALIGN): Add casts to simplify usage.

(BLOCK_ALIGN, BLOCK_BYTES, ABLOCKS_PADDING, ABLOCKS_SIZE)
(ABLOCKS_BYTES, ABLOCK_ABASE, ABLOCKS_BUSY, ABLOCKS_BASE): New macros.
(struct ablock, struct ablocks): New types.
(free_ablock): New global var.
(lisp_align_malloc, lisp_align_free): New functions.
(FLOAT_BLOCK_SIZE): Redefine in terms of BLOCK_BYTES.
(struct float_block): Reorder and add gcmarkbits.
(GETMARKBIT, SETMARKBIT, UNSETMARKBIT, FLOAT_BLOCK, FLOAT_INDEX)
(FLOAT_MARKED_P, FLOAT_MARK, FLOAT_UNMARK): New macros.
(init_float, make_float): Use lisp_align_malloc.
(free_float, live_float_p): Don't use `type' any more.
(make_float): Use FLOAT_UNMARK to access to mark bit.
(mark_maybe_object, mark_maybe_pointer, survives_gc_p):
Use FLOAT_MARKED_P to access the mark bit.
(pure_alloc): Simplify use of ALIGN.
(mark_object): Use FLOAT_MARK to access the mark bit.
(gc_sweep): Use new macros to access the float's mark bit.
(init_alloc_once): Init free_ablock.

1 files changed, 255 insertions, 36 deletions

diff --git a/src/alloc.c b/src/alloc.c
index 8dfeb25edf4..4ec3a1c3863 100644
--- a/src/alloc.c
+++ b/src/alloc.c
@@ -21,6 +21,7 @@ Boston, MA 02111-1307, USA.  */
 
 #include <config.h>
 #include <stdio.h>
+#include <limits.h>             /* For CHAR_BIT.  */
 
 #ifdef ALLOC_DEBUG
 #undef INLINE
@@ -418,8 +419,9 @@ static POINTER_TYPE *pure_alloc P_ ((size_t, int));
 /* Value is SZ rounded up to the next multiple of ALIGNMENT.
    ALIGNMENT must be a power of 2.  */
 
-#define ALIGN(SZ, ALIGNMENT) \
-  (((SZ) + (ALIGNMENT) - 1) & ~((ALIGNMENT) - 1))
+#define ALIGN(ptr, ALIGNMENT) \
+  ((POINTER_TYPE *) ((((EMACS_UINT)(ptr)) + (ALIGNMENT) - 1) \
+                     & ~((ALIGNMENT) - 1)))
 
 
 
@@ -635,6 +637,202 @@ lisp_free (block)
   UNBLOCK_INPUT;
 }
 
+/* Allocation of aligned blocks of memory to store Lisp data.              */
+/* The entry point is lisp_align_malloc which returns blocks of at most    */
+/* BLOCK_BYTES and guarantees they are aligned on a BLOCK_ALIGN boundary.  */
+
+
+/* BLOCK_ALIGN has to be a power of 2.  */
+#define BLOCK_ALIGN (1 << 10)
+#define BLOCK_BYTES \
+  (BLOCK_ALIGN - sizeof (struct aligned_block *) - ABLOCKS_PADDING)
+
+/* Internal data structures and constants.  */
+
+/* Padding to leave at the end of a malloc'd block.  This is to give
+   malloc a chance to minimize the amount of memory wasted to alignment.
+   It should be tuned to the particular malloc library used.
+   The current setting is based on glibc-2.3.2.  */
+#define ABLOCKS_PADDING 0
+#define ABLOCKS_SIZE 16
+
+/* An aligned block of memory.  */
+struct ablock
+{
+  union
+  {
+    char payload[BLOCK_BYTES];
+    struct ablock *next_free;
+  } x;
+  /* `abase' is the aligned base of the ablocks.  */
+  /* It is overloaded to hold the virtual `busy' field that counts
+     the number of used ablock in the parent ablocks.
+     The first ablock has the `busy' field, the others have the `abase'
+     field.  To tell the difference, we assume that pointers will have
+     integer values larger than 2 * ABLOCKS_SIZE.  The lowest bit of `busy'
+     is used to tell whether the real base of the parent ablocks is `abase'
+     (if not, the word before the first ablock holds a pointer to the
+     real base).  */
+  struct ablocks *abase;
+  /* The padding of all but the last ablock is unused.  The padding of
+     the last ablock in an ablocks is not allocated.  */
+  char padding[ABLOCKS_PADDING];
+};
+
+/* A bunch of consecutive aligned blocks.  */
+struct ablocks
+{
+  struct ablock blocks[ABLOCKS_SIZE];
+};
+
+/* Size of the block requested from malloc or memalign.  */
+#define ABLOCKS_BYTES (sizeof (struct ablocks) - ABLOCKS_PADDING)
+
+#define ABLOCK_ABASE(block) \
+  (((unsigned long) (block)->abase) <= (1 + 2 * ABLOCKS_SIZE)   \
+   ? (struct ablocks *)(block)                                  \
+   : (block)->abase)
+
+/* Virtual `busy' field.  */
+#define ABLOCKS_BUSY(abase) ((abase)->blocks[0].abase)
+
+/* Pointer to the (not necessarily aligned) malloc block.  */
+#define ABLOCKS_BASE(abase) \
+  (1 & (int) ABLOCKS_BUSY (abase) ? abase : ((void**)abase)[-1])
+
+/* The list of free ablock.   */
+static struct ablock *free_ablock;
+
+/* Allocate an aligned block of nbytes.
+   Alignment is on a multiple of BLOCK_ALIGN and `nbytes' has to be
+   smaller or equal to BLOCK_BYTES.  */
+static POINTER_TYPE *
+lisp_align_malloc (nbytes, type)
+     size_t nbytes;
+     enum mem_type type;
+{
+  void *base, *val;
+  struct ablocks *abase;
+
+  eassert (nbytes <= BLOCK_BYTES);
+
+  BLOCK_INPUT;
+
+#ifdef GC_MALLOC_CHECK
+  allocated_mem_type = type;
+#endif
+
+  if (!free_ablock)
+    {
+      int i, aligned;
+
+#ifdef DOUG_LEA_MALLOC
+      /* Prevent mmap'ing the chunk.  Lisp data may not be mmap'ed
+         because mapped region contents are not preserved in
+         a dumped Emacs.  */
+      mallopt (M_MMAP_MAX, 0);
+#endif
+
+      base = malloc (ABLOCKS_BYTES);
+      abase = ALIGN (base, BLOCK_ALIGN);
+
+      aligned = (base == abase);
+      if (!aligned)
+        ((void**)abase)[-1] = base;
+
+#ifdef DOUG_LEA_MALLOC
+      /* Back to a reasonable maximum of mmap'ed areas.  */
+      mallopt (M_MMAP_MAX, MMAP_MAX_AREAS);
+#endif
+
+      /* Initialize the blocks and put them on the free list.
+         Is `base' was not properly aligned, we can't use the last block.  */
+      for (i = 0; i < (aligned ? ABLOCKS_SIZE : ABLOCKS_SIZE - 1); i++)
+        {
+          abase->blocks[i].abase = abase;
+          abase->blocks[i].x.next_free = free_ablock;
+          free_ablock = &abase->blocks[i];
+        }
+      ABLOCKS_BUSY (abase) = (struct ablocks *) aligned;
+
+      eassert (ABLOCK_ABASE (&abase->blocks[3]) == abase); /* 3 is arbitrary */
+      eassert (ABLOCK_ABASE (&abase->blocks[0]) == abase);
+      eassert (ABLOCKS_BASE (abase) == base);
+      eassert (aligned == (int)ABLOCKS_BUSY (abase));
+    }
+
+  abase = ABLOCK_ABASE (free_ablock);
+  ABLOCKS_BUSY (abase) = (struct ablocks *) (2 + (int) ABLOCKS_BUSY (abase));
+  val = free_ablock;
+  free_ablock = free_ablock->x.next_free;
+
+  /* If the memory just allocated cannot be addressed thru a Lisp
+     object's pointer, and it needs to be,
+     that's equivalent to running out of memory.  */
+  if (val && type != MEM_TYPE_NON_LISP)
+    {
+      Lisp_Object tem;
+      XSETCONS (tem, (char *) val + nbytes - 1);
+      if ((char *) XCONS (tem) != (char *) val + nbytes - 1)
+        {
+          lisp_malloc_loser = val;
+          free (val);
+          val = 0;
+        }
+    }
+
+#if GC_MARK_STACK && !defined GC_MALLOC_CHECK
+  if (val && type != MEM_TYPE_NON_LISP)
+    mem_insert (val, (char *) val + nbytes, type);
+#endif
+
+  UNBLOCK_INPUT;
+  if (!val && nbytes)
+    memory_full ();
+
+  eassert (0 == ((EMACS_UINT)val) % BLOCK_ALIGN);
+  return val;
+}
+
+static void
+lisp_align_free (block)
+     POINTER_TYPE *block;
+{
+  struct ablock *ablock = block;
+  struct ablocks *abase = ABLOCK_ABASE (ablock);
+
+  BLOCK_INPUT;
+#if GC_MARK_STACK && !defined GC_MALLOC_CHECK
+  mem_delete (mem_find (block));
+#endif
+  /* Put on free list.  */
+  ablock->x.next_free = free_ablock;
+  free_ablock = ablock;
+  /* Update busy count.  */
+  ABLOCKS_BUSY (abase) = (struct ablocks *) (-2 + (int) ABLOCKS_BUSY (abase));
+  
+  if (2 > (int) ABLOCKS_BUSY (abase))
+    { /* All the blocks are free.  */
+      int i = 0, aligned = (int) ABLOCKS_BUSY (abase);
+      struct ablock **tem = &free_ablock;
+      struct ablock *atop = &abase->blocks[aligned ? ABLOCKS_SIZE : ABLOCKS_SIZE - 1];
+
+      while (*tem)
+        {
+          if (*tem >= (struct ablock *) abase && *tem < atop)
+            {
+              i++;
+              *tem = (*tem)->x.next_free;
+            }
+          else
+            tem = &(*tem)->x.next_free;
+        }
+      eassert ((aligned & 1) == aligned);
+      eassert (i == (aligned ? ABLOCKS_SIZE : ABLOCKS_SIZE - 1));
+      free (ABLOCKS_BASE (abase));
+    }
+  UNBLOCK_INPUT;
+}
 
 /* Return a new buffer structure allocated from the heap with
    a call to lisp_malloc.  */
@@ -1899,21 +2097,48 @@ make_uninit_multibyte_string (nchars, nbytes)
 /* We store float cells inside of float_blocks, allocating a new
    float_block with malloc whenever necessary.  Float cells reclaimed
    by GC are put on a free list to be reallocated before allocating
-   any new float cells from the latest float_block.
-
-   Each float_block is just under 1020 bytes long, since malloc really
-   allocates in units of powers of two and uses 4 bytes for its own
-   overhead. */
+   any new float cells from the latest float_block.  */
 
 #define FLOAT_BLOCK_SIZE \
-  ((1020 - sizeof (struct float_block *)) / sizeof (struct Lisp_Float))
+  (((BLOCK_BYTES - sizeof (struct float_block *)) * CHAR_BIT) \
+   / (sizeof (struct Lisp_Float) * CHAR_BIT + 1))
+
+#define GETMARKBIT(block,n)                             \
+  (((block)->gcmarkbits[(n) / (sizeof(int) * CHAR_BIT)] \
+    >> ((n) % (sizeof(int) * CHAR_BIT)))                \
+   & 1)
+
+#define SETMARKBIT(block,n)                             \
+  (block)->gcmarkbits[(n) / (sizeof(int) * CHAR_BIT)]   \
+  |= 1 << ((n) % (sizeof(int) * CHAR_BIT))
+
+#define UNSETMARKBIT(block,n)                           \
+  (block)->gcmarkbits[(n) / (sizeof(int) * CHAR_BIT)]   \
+  &= ~(1 << ((n) % (sizeof(int) * CHAR_BIT)))
+
+#define FLOAT_BLOCK(fptr) \
+  ((struct float_block *)(((EMACS_UINT)(fptr)) & ~(BLOCK_ALIGN - 1)))
+
+#define FLOAT_INDEX(fptr) \
+  ((((EMACS_UINT)(fptr)) & (BLOCK_ALIGN - 1)) / sizeof (struct Lisp_Float))
 
 struct float_block
 {
-  struct float_block *next;
+  /* Place `floats' at the beginning, to ease up FLOAT_INDEX's job.  */
   struct Lisp_Float floats[FLOAT_BLOCK_SIZE];
+  int gcmarkbits[1 + FLOAT_BLOCK_SIZE / (sizeof(int) * CHAR_BIT)];
+  struct float_block *next;
 };
 
+#define FLOAT_MARKED_P(fptr) \
+  GETMARKBIT (FLOAT_BLOCK (fptr), FLOAT_INDEX ((fptr)))
+
+#define FLOAT_MARK(fptr) \
+  SETMARKBIT (FLOAT_BLOCK (fptr), FLOAT_INDEX ((fptr)))
+
+#define FLOAT_UNMARK(fptr) \
+  UNSETMARKBIT (FLOAT_BLOCK (fptr), FLOAT_INDEX ((fptr)))
+
 /* Current float_block.  */
 
 struct float_block *float_block;
@@ -1936,10 +2161,11 @@ struct Lisp_Float *float_free_list;
 void
 init_float ()
 {
-  float_block = (struct float_block *) lisp_malloc (sizeof *float_block,
-                                                    MEM_TYPE_FLOAT);
+  float_block = (struct float_block *) lisp_align_malloc (sizeof *float_block,
+                                                          MEM_TYPE_FLOAT);
   float_block->next = 0;
   bzero ((char *) float_block->floats, sizeof float_block->floats);
+  bzero ((char *) float_block->gcmarkbits, sizeof float_block->gcmarkbits);
   float_block_index = 0;
   float_free_list = 0;
   n_float_blocks = 1;
@@ -1953,9 +2179,6 @@ free_float (ptr)
      struct Lisp_Float *ptr;
 {
   *(struct Lisp_Float **)&ptr->data = float_free_list;
-#if GC_MARK_STACK
-  ptr->type = Vdead;
-#endif
   float_free_list = ptr;
 }
 
@@ -1981,8 +2204,8 @@ make_float (float_value)
         {
           register struct float_block *new;
 
-          new = (struct float_block *) lisp_malloc (sizeof *new,
-                                                    MEM_TYPE_FLOAT);
+          new = (struct float_block *) lisp_align_malloc (sizeof *new,
+                                                          MEM_TYPE_FLOAT);
           new->next = float_block;
           float_block = new;
           float_block_index = 0;
@@ -1992,7 +2215,7 @@ make_float (float_value)
     }
 
   XFLOAT_DATA (val) = float_value;
-  XSETFASTINT (XFLOAT (val)->type, 0);  /* bug chasing -wsr */
+  FLOAT_UNMARK (XFLOAT (val));
   consing_since_gc += sizeof (struct Lisp_Float);
   floats_consed++;
   return val;
@@ -3240,14 +3463,12 @@ live_float_p (m, p)
       struct float_block *b = (struct float_block *) m->start;
       int offset = (char *) p - (char *) &b->floats[0];
 
-      /* P must point to the start of a Lisp_Float, not be
-         one of the unused cells in the current float block,
-         and not be on the free-list.  */
+      /* P must point to the start of a Lisp_Float and not be
+         one of the unused cells in the current float block.  */
       return (offset >= 0
               && offset % sizeof b->floats[0] == 0
               && (b != float_block
-                  || offset / sizeof b->floats[0] < float_block_index)
-              && !EQ (((struct Lisp_Float *) p)->type, Vdead));
+                  || offset / sizeof b->floats[0] < float_block_index));
     }
   else
     return 0;
@@ -3394,8 +3615,7 @@ mark_maybe_object (obj)
           break;
 
         case Lisp_Float:
-          mark_p = (live_float_p (m, po)
-                    && !XMARKBIT (XFLOAT (obj)->type));
+          mark_p = (live_float_p (m, po) && !FLOAT_MARKED_P (XFLOAT (obj)));
           break;
 
         case Lisp_Vectorlike:
@@ -3483,8 +3703,7 @@ mark_maybe_pointer (p)
           break;
 
         case MEM_TYPE_FLOAT:
-          if (live_float_p (m, p)
-              && !XMARKBIT (((struct Lisp_Float *) p)->type))
+          if (live_float_p (m, p) && !FLOAT_MARKED_P (p))
             XSETFLOAT (obj, p);
           break;
 
@@ -3741,7 +3960,7 @@ mark_stack ()
 
   /* This trick flushes the register windows so that all the state of
      the process is contained in the stack.  */
-  /* Fixme: Code in the Boehm GC sugests flushing (with `flushrs') is
+  /* Fixme: Code in the Boehm GC suggests flushing (with `flushrs') is
      needed on ia64 too.  See mach_dep.c, where it also says inline
      assembler doesn't work with relevant proprietary compilers.  */
 #ifdef sparc
@@ -3823,7 +4042,7 @@ pure_alloc (size, type)
     }
 
  again:
-  result = (POINTER_TYPE *) ALIGN ((EMACS_UINT)purebeg + pure_bytes_used, alignment);
+  result = ALIGN (purebeg + pure_bytes_used, alignment);
   pure_bytes_used = ((char *)result - (char *)purebeg) + size;
 
   if (pure_bytes_used <= pure_size)
@@ -4825,7 +5044,7 @@ mark_object (argptr)
 
     case Lisp_Float:
       CHECK_ALLOCATED_AND_LIVE (live_float_p);
-      XMARK (XFLOAT (obj)->type);
+      FLOAT_MARK (XFLOAT (obj));
       break;
 
     case Lisp_Int:
@@ -4948,7 +5167,7 @@ survives_gc_p (obj)
       break;
 
     case Lisp_Float:
-      survives_p = XMARKBIT (XFLOAT (obj)->type);
+      survives_p = FLOAT_MARKED_P (XFLOAT (obj));
       break;
 
     default:
@@ -5039,19 +5258,16 @@ gc_sweep ()
         register int i;
         int this_free = 0;
         for (i = 0; i < lim; i++)
-          if (!XMARKBIT (fblk->floats[i].type))
+          if (!FLOAT_MARKED_P (&fblk->floats[i]))
             {
               this_free++;
               *(struct Lisp_Float **)&fblk->floats[i].data = float_free_list;
               float_free_list = &fblk->floats[i];
-#if GC_MARK_STACK
-              float_free_list->type = Vdead;
-#endif
             }
           else
             {
               num_used++;
-              XUNMARK (fblk->floats[i].type);
+              FLOAT_UNMARK (&fblk->floats[i]);
             }
         lim = FLOAT_BLOCK_SIZE;
         /* If this block contains only free floats and we have already
@@ -5062,7 +5278,7 @@ gc_sweep ()
             *fprev = fblk->next;
             /* Unhook from the free list.  */
             float_free_list = *(struct Lisp_Float **) &fblk->floats[0].data;
-            lisp_free (fblk);
+            lisp_align_free (fblk);
             n_float_blocks--;
           }
         else
@@ -5373,6 +5589,9 @@ init_alloc_once ()
   pure_bytes_used = 0;
   pure_bytes_used_before_overflow = 0;
 
+  /* Initialize the list of free aligned blocks.  */
+  free_ablock = NULL;
+
 #if GC_MARK_STACK || defined GC_MALLOC_CHECK
   mem_init ();
   Vdead = make_pure_string ("DEAD", 4, 4, 0);