Mesa (master): gallium/util: Don't use __builtin_clrsb in util_last_bit().

[Matt Turner]

Module: Mesa
Branch: master
Commit: 32e98e8ef06f0bb6ad55f9fb5858be77c03367b0
URL:    http://cgit.freedesktop.org/mesa/mesa/commit/?id=32e98e8ef06f0bb6ad55f9fb5858be77c03367b0

Author: Matt Turner <mattst88 at gmail.com>
Date:   Mon Feb  2 17:26:49 2015 -0800

gallium/util: Don't use __builtin_clrsb in util_last_bit().

Unclear circumstances lead to undefined symbols on x86.

Bugzilla: https://bugs.gentoo.org/show_bug.cgi?id=536916
Cc: mesa-stable at lists.freedesktop.org
Reviewed-by: Ilia Mirkin <imirkin at alum.mit.edu>

---

 src/gallium/auxiliary/util/u_math.h |    4 ----
 1 file changed, 4 deletions(-)

diff --git a/src/gallium/auxiliary/util/u_math.h b/src/gallium/auxiliary/util/u_math.h
index 19c7343..ca6d0f1 100644
--- a/src/gallium/auxiliary/util/u_math.h
+++ b/src/gallium/auxiliary/util/u_math.h
@@ -561,14 +561,10 @@ util_last_bit(unsigned u)
 static INLINE unsigned
 util_last_bit_signed(int i)
 {
-#if defined(__GNUC__) && ((__GNUC__ * 100 + __GNUC_MINOR__) >= 407) && !defined(__INTEL_COMPILER)
-   return 31 - __builtin_clrsb(i);
-#else
    if (i >= 0)
       return util_last_bit(i);
    else
       return util_last_bit(~(unsigned)i);
-#endif
 }
 
 /* Destructively loop over all of the bits in a mask as in: