[Pixman] [PATCH] Use a compile-time constant for the "K" constraint in the MMX detection.
Søren Sandman
sandmann at cs.au.dk
Sun Jul 1 14:03:25 PDT 2012
From: Søren Sandmann Pedersen <ssp at redhat.com>
When compiling with -O0, gcc doesn't understand that in
signed char x = 0;
...
asm ("...",
: "K" (x));
x is constant. Fix this by using an immediate constant instead of a
variable.
---
configure.ac | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)
diff --git a/configure.ac b/configure.ac
index 2b9d1ba..36f423e 100644
--- a/configure.ac
+++ b/configure.ac
@@ -351,12 +351,11 @@ AC_COMPILE_IFELSE([AC_LANG_SOURCE([[
int main () {
__m64 v = _mm_cvtsi32_si64 (1);
__m64 w;
- signed char x = 0;
/* Some versions of clang will choke on K */
asm ("pshufw %2, %1, %0\n\t"
: "=y" (w)
- : "y" (v), "K" (x)
+ : "y" (v), "K" (5)
);
return _mm_cvtsi64_si32 (v);
--
1.7.10.4
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