Re: malloc attributes and realloc

["Kaveh R. Ghazi" <ghazi at caip dot rutgers dot edu>]

 > From: "Zack Weinberg" <zack@codesourcery.com>
 > 
 > "Kaveh R. Ghazi" <ghazi@caip.rutgers.edu> writes:
 > 
 > > Another datapoint, I tried disabling the libiberty macro
 > > ATTRIBUTE_MALLOC which is applied to several allocation functions in
 > > libiberty like xmalloc, etc.  I rebootstrapped GCC and found that
 > > without the attribute it slowed down 1% to 1.5% compiling combine.c at
 > > -g -O2.
 > >
 > > Note many (most?) allocation in GCC occurs in other functions besides
 > > the few libiberty functions with the attribute.  So I think the
 > > optimization is pretty good to get as much as it does.
 > 
 > Hmm.  Wanna put ATTRIBUTE_MALLOC on ggc_alloc* in ggc.h and see what
 > kind of speedup you get?
 > zw



Odd, cc1 shrinks by 500 bytes but >slows down< 1.7%.  Now I'd _really_
like it if someone would try and reproduce my results...

Here's the patch I tested on sparc-sun-solaris2.7 with
--enable-languages=c --disable-checking --disable-nls
--enable-multilib=no


--- ggc.h~	2003-12-21 20:01:18.000000000 -0500
+++ ggc.h	2004-01-03 20:51:48.765601000 -0500
@@ -210,19 +210,19 @@ extern struct alloc_zone *rtl_zone;
 extern struct alloc_zone *tree_zone;
 
 /* The internal primitive.  */
-extern void *ggc_alloc (size_t);
+extern void *ggc_alloc (size_t) ATTRIBUTE_MALLOC;
 /* Allocate an object into the specified allocation zone.  */
-extern void *ggc_alloc_zone (size_t, struct alloc_zone *);
+extern void *ggc_alloc_zone (size_t, struct alloc_zone *) ATTRIBUTE_MALLOC;
 /* Allocate an object of the specified type and size.  */
-extern void *ggc_alloc_typed (enum gt_types_enum, size_t);
+extern void *ggc_alloc_typed (enum gt_types_enum, size_t) ATTRIBUTE_MALLOC;
 /* Like ggc_alloc, but allocates cleared memory.  */
-extern void *ggc_alloc_cleared (size_t);
+extern void *ggc_alloc_cleared (size_t) ATTRIBUTE_MALLOC;
 /* Like ggc_alloc_zone, but allocates cleared memory.  */
-extern void *ggc_alloc_cleared_zone (size_t, struct alloc_zone *);
+extern void *ggc_alloc_cleared_zone (size_t, struct alloc_zone *) ATTRIBUTE_MALLOC;
 /* Resize a block.  */
-extern void *ggc_realloc (void *, size_t);
+extern void *ggc_realloc (void *, size_t) ATTRIBUTE_MALLOC;
 /* Like ggc_alloc_cleared, but performs a multiplication.  */
-extern void *ggc_calloc (size_t, size_t);
+extern void *ggc_calloc (size_t, size_t) ATTRIBUTE_MALLOC;
 
 #define ggc_alloc_rtx(CODE)                    \
   ((rtx) ggc_alloc_typed (gt_ggc_e_7rtx_def, RTX_SIZE (CODE)))
@@ -240,13 +240,13 @@ extern void *ggc_calloc (size_t, size_t)
   splay_tree_new_with_allocator (COMPARE, NULL, NULL,			 \
                                  &ggc_splay_alloc, &ggc_splay_dont_free, \
 				 NULL)
-extern void *ggc_splay_alloc (int, void *);
+extern void *ggc_splay_alloc (int, void *) ATTRIBUTE_MALLOC;
 extern void ggc_splay_dont_free (void *, void *);
 
 /* Allocate a gc-able string, and fill it with LENGTH bytes from CONTENTS.
    If LENGTH is -1, then CONTENTS is assumed to be a
    null-terminated string and the memory sized accordingly.  */
-extern const char *ggc_alloc_string (const char *contents, int length);
+extern const char *ggc_alloc_string (const char *contents, int length) ATTRIBUTE_MALLOC;
 
 /* Make a copy of S, in GC-able memory.  */
 #define ggc_strdup(S) ggc_alloc_string((S), -1)