[MPlayer-dev-eng] [RFC] disable fastmemcpy on x86-64 by default
Reimar D?ffinger
Reimar.Doeffinger at stud.uni-karlsruhe.de
Sun May 27 18:19:48 CEST 2007
Hello,
since SSE is part of the x86-64 architecture, at least glibc makes use
of it for its memcpy and some quick (and imprecise) tests indicate that
it's at least not slower.
So what do you think about attached patch? Can someone do more concise
benchmarks?
Greetings,
Reimar Döffinger
-------------- next part --------------
Index: configure
===================================================================
--- configure (revision 23390)
+++ configure (working copy)
@@ -575,7 +576,7 @@
_sgiaudio=auto
_sunaudio=auto
_alsa=auto
-_fastmemcpy=yes
+_fastmemcpy=auto
_unrarlib=yes
_win32dll=auto
_select=yes
@@ -6521,6 +6542,12 @@
echores "$_mencoder"
echocheck "fastmemcpy"
+if test "$_fastmemcpy" = auto ; then
+ _fastmemcpy=yes
+ # x86-64 default memcpy should be just as good and
+ # can be replaced by a compiler-builtin
+ x86_64 && _fastmemcpy=no
+fi
# fastmemcpy check is done earlier with tests of CPU & binutils features
if test "$_fastmemcpy" = yes ; then
_def_fastmemcpy='#define USE_FASTMEMCPY 1'
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