Mesa (master): configure: Use -fno-builtin-memcmp.

[Jose Fonseca]

Module: Mesa
Branch: master
Commit: 1448bdf1c0995e3ac2e0f97c51e5e2d73eded8e0
URL:    http://cgit.freedesktop.org/mesa/mesa/commit/?id=1448bdf1c0995e3ac2e0f97c51e5e2d73eded8e0

Author: José Fonseca <jfonseca at vmware.com>
Date:   Fri Oct 14 18:28:55 2011 +0100

configure: Use -fno-builtin-memcmp.

Issue spotted by Adam Jackson <ajax at redhat.com>.

http://lists.freedesktop.org/archives/mesa-dev/2011-June/009077.html

---

 configure.ac |    8 ++++++++
 1 files changed, 8 insertions(+), 0 deletions(-)

diff --git a/configure.ac b/configure.ac
index 49e81ad..ae7b36b 100644
--- a/configure.ac
+++ b/configure.ac
@@ -172,6 +172,10 @@ if test "x$GCC" = xyes; then
 
     # Work around aliasing bugs - developers should comment this out
     CFLAGS="$CFLAGS -fno-strict-aliasing"
+
+    # gcc's builtin memcmp is slower than glibc's
+    # http://gcc.gnu.org/bugzilla/show_bug.cgi?id=43052
+    CFLAGS="$CFLAGS -fno-builtin-memcmp"
 fi
 if test "x$GXX" = xyes; then
     CXXFLAGS="$CXXFLAGS -Wall"
@@ -191,6 +195,10 @@ if test "x$GXX" = xyes; then
 
     # Work around aliasing bugs - developers should comment this out
     CXXFLAGS="$CXXFLAGS -fno-strict-aliasing"
+
+    # gcc's builtin memcmp is slower than glibc's
+    # http://gcc.gnu.org/bugzilla/show_bug.cgi?id=43052
+    CXXFLAGS="$CXXFLAGS -fno-builtin-memcmp"
 fi
 
 dnl even if the compiler appears to support it, using visibility attributes isn't