Ibuffer change marks

[gnu-emacs] / src / alloc.c

diff --git a/src/alloc.c b/src/alloc.c
index 3feed51b1e95e53700f2c344d8db4fb530596c1d..e25d91ff8aa072a177681dbe3ee2ff27de9527df 100644 (file)
--- a/src/alloc.c
+++ b/src/alloc.c
@@ -489,7 +489,7 @@ static void *pure_alloc (size_t, int);
 /* Return PTR rounded up to the next multiple of ALIGNMENT.  */
 
 static void *
-ALIGN (void *ptr, int alignment)
+pointer_align (void *ptr, int alignment)
 {
   return (void *) ROUNDUP ((uintptr_t) ptr, alignment);
 }
@@ -1178,16 +1178,18 @@ struct ablock
     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).  */
+
+  /* ABASE is the aligned base of the ablocks.  It is overloaded to
+     hold a virtual "busy" field that counts twice the number of used
+     ablock values in the parent ablocks, plus one if the real base of
+     the parent ablocks is ABASE (if the "busy" field is even, the
+     word before the first ablock holds a pointer to the real base).
+     The first ablock has a "busy" ABASE, and the others have an
+     ordinary pointer ABASE.  To tell the difference, the code assumes
+     that pointers, when cast to uintptr_t, are at least 2 *
+     ABLOCKS_SIZE + 1.  */
   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.  */
 #if BLOCK_PADDING
@@ -1206,18 +1208,18 @@ struct ablocks
 
 #define ABLOCK_ABASE(block) \
   (((uintptr_t) (block)->abase) <= (1 + 2 * ABLOCKS_SIZE)      \
-   ? (struct ablocks *)(block)                                 \
+   ? (struct ablocks *) (block)                                        \
    : (block)->abase)
 
 /* Virtual `busy' field.  */
-#define ABLOCKS_BUSY(abase) ((abase)->blocks[0].abase)
+#define ABLOCKS_BUSY(a_base) ((a_base)->blocks[0].abase)
 
 /* Pointer to the (not necessarily aligned) malloc block.  */
 #ifdef USE_ALIGNED_ALLOC
 #define ABLOCKS_BASE(abase) (abase)
 #else
 #define ABLOCKS_BASE(abase) \
-  (1 & (intptr_t) ABLOCKS_BUSY (abase) ? abase : ((void **)abase)[-1])
+  (1 & (intptr_t) ABLOCKS_BUSY (abase) ? abase : ((void **) (abase))[-1])
 #endif
 
 /* The list of free ablock.   */
@@ -1243,7 +1245,7 @@ lisp_align_malloc (size_t nbytes, enum mem_type type)
   if (!free_ablock)
     {
       int i;
-      intptr_t aligned; /* int gets warning casting to 64-bit pointer.  */
+      bool aligned;
 
 #ifdef DOUG_LEA_MALLOC
       if (!mmap_lisp_allowed_p ())
@@ -1254,7 +1256,7 @@ lisp_align_malloc (size_t nbytes, enum mem_type type)
       abase = base = aligned_alloc (BLOCK_ALIGN, ABLOCKS_BYTES);
 #else
       base = malloc (ABLOCKS_BYTES);
-      abase = ALIGN (base, BLOCK_ALIGN);
+      abase = pointer_align (base, BLOCK_ALIGN);
 #endif
 
       if (base == 0)
@@ -1299,13 +1301,14 @@ lisp_align_malloc (size_t nbytes, enum mem_type type)
          abase->blocks[i].x.next_free = free_ablock;
          free_ablock = &abase->blocks[i];
        }
-      ABLOCKS_BUSY (abase) = (struct ablocks *) aligned;
+      intptr_t ialigned = aligned;
+      ABLOCKS_BUSY (abase) = (struct ablocks *) ialigned;
 
-      eassert (0 == ((uintptr_t) abase) % BLOCK_ALIGN);
+      eassert ((uintptr_t) abase % BLOCK_ALIGN == 0);
       eassert (ABLOCK_ABASE (&abase->blocks[3]) == abase); /* 3 is arbitrary */
       eassert (ABLOCK_ABASE (&abase->blocks[0]) == abase);
       eassert (ABLOCKS_BASE (abase) == base);
-      eassert (aligned == (intptr_t) ABLOCKS_BUSY (abase));
+      eassert ((intptr_t) ABLOCKS_BUSY (abase) == aligned);
     }
 
   abase = ABLOCK_ABASE (free_ablock);
@@ -1341,12 +1344,14 @@ lisp_align_free (void *block)
   ablock->x.next_free = free_ablock;
   free_ablock = ablock;
   /* Update busy count.  */
-  ABLOCKS_BUSY (abase)
-    = (struct ablocks *) (-2 + (intptr_t) ABLOCKS_BUSY (abase));
+  intptr_t busy = (intptr_t) ABLOCKS_BUSY (abase) - 2;
+  eassume (0 <= busy && busy <= 2 * ABLOCKS_SIZE - 1);
+  ABLOCKS_BUSY (abase) = (struct ablocks *) busy;
 
-  if (2 > (intptr_t) ABLOCKS_BUSY (abase))
+  if (busy < 2)
     { /* All the blocks are free.  */
-      int i = 0, aligned = (intptr_t) ABLOCKS_BUSY (abase);
+      int i = 0;
+      bool aligned = busy;
       struct ablock **tem = &free_ablock;
       struct ablock *atop = &abase->blocks[aligned ? ABLOCKS_SIZE : ABLOCKS_SIZE - 1];
 
@@ -5173,7 +5178,7 @@ pure_alloc (size_t size, int type)
     {
       /* Allocate space for a Lisp object from the beginning of the free
         space with taking account of alignment.  */
-      result = ALIGN (purebeg + pure_bytes_used_lisp, GCALIGNMENT);
+      result = pointer_align (purebeg + pure_bytes_used_lisp, GCALIGNMENT);
       pure_bytes_used_lisp = ((char *)result - (char *)purebeg) + size;
     }
   else
@@ -6130,7 +6135,7 @@ mark_face_cache (struct face_cache *c)
       int i, j;
       for (i = 0; i < c->used; ++i)
        {
-         struct face *face = FACE_OPT_FROM_ID (c->f, i);
+         struct face *face = FACE_FROM_ID_OR_NULL (c->f, i);
 
          if (face)
            {