[commit: packages/integer-gmp] master: Refactor `stgReallocForGMP` to use `memcpy` (66ea120)

[git at git.haskell.org]

Repository : ssh://git@git.haskell.org/integer-gmp

On branch  : master
Link       : http://git.haskell.org/packages/integer-gmp.git/commitdiff/66ea120f3a31ba8d81556fa121f9b998eef570b8

>---------------------------------------------------------------

commit 66ea120f3a31ba8d81556fa121f9b998eef570b8
Author: Herbert Valerio Riedel <hvr at gnu.org>
Date:   Fri Jan 3 22:58:32 2014 +0100

    Refactor `stgReallocForGMP` to use `memcpy`
    
    GCC is able to generate better code when using `memcpy` instead of
    manually copying bytes in a loop. Otoh, `stgAllocForGMP` is typically
    called for enlarging initial single-limb structures (see also #8647 for
    more information) and so this minor optimization won't be very visible
    in measurements.
    
    Signed-off-by: Herbert Valerio Riedel <hvr at gnu.org>


>---------------------------------------------------------------

66ea120f3a31ba8d81556fa121f9b998eef570b8
 cbits/alloc.c |   18 +++++-------------
 1 file changed, 5 insertions(+), 13 deletions(-)

diff --git a/cbits/alloc.c b/cbits/alloc.c
index 1e2d56b..e711110 100644
--- a/cbits/alloc.c
+++ b/cbits/alloc.c
@@ -4,6 +4,8 @@
  *
  * ---------------------------------------------------------------------------*/
 
+#include <string.h>
+
 #include "Rts.h"
 
 #include "gmp.h"
@@ -83,19 +85,9 @@ stgAllocForGMP (size_t size_in_bytes)
 void *
 stgReallocForGMP (void *ptr, size_t old_size, size_t new_size)
 {
-    size_t min_size;
-    void *new_stuff_ptr = stgAllocForGMP(new_size);
-    nat i = 0;
-    char *p = (char *) ptr;
-    char *q = (char *) new_stuff_ptr;
-
-    min_size = old_size < new_size ? old_size : new_size;
-    /* TODO: use memcpy */
-    for (; i < min_size; i++, p++, q++) {
-        *q = *p;
-    }
-
-    return(new_stuff_ptr);
+  size_t min_size = old_size < new_size ? old_size : new_size;
+
+  return memcpy(stgAllocForGMP(new_size), ptr, min_size);
 }
 
 void