scons: Use -fno-builtin-memcmp.
ipers framerate on llmvpipe improves 60%.
Issue spotted by Adam Jackson <ajax at redhat.com>.
http://lists.freedesktop.org/archives/mesa-dev/2011-June/009077.html
diff --git a/scons/gallium.py b/scons/gallium.py
index 1c9c0ea..c3350b3 100755
--- a/scons/gallium.py
+++ b/scons/gallium.py
@@ -361,6 +361,9 @@
ccflags += ['-O0']
else:
ccflags += ['-O3']
+ # gcc's builtin memcmp is slower than glibc's
+ # http://gcc.gnu.org/bugzilla/show_bug.cgi?id=43052
+ ccflags += ['-fno-builtin-memcmp']
# Work around aliasing bugs - developers should comment this out
ccflags += ['-fno-strict-aliasing']
ccflags += ['-g']