[PATCH] Disable x87 inline functions for x86_64 and SSE [BZ #17262]

[Siddhesh Poyarekar <siddhesh at redhat dot com>]

Hi,

Since:

commit 409e00bd69b8d8dd74d7327085351d26769ea6fc
Author: H.J. Lu <hjl.tools@gmail.com>
Date:   Wed Jan 29 07:51:41 2014 -0800

    Disable x87 inline functions for SSE2 math
    
    When i386 and x86-64 mathinline.h was merged into a single mathinline.h,
    "gcc -m32" enables x87 inline functions on x86-64 even when -mfpmath=sse
    and SSE2 is enabled.  It is a regression on x86-64.  We should check
    __SSE2_MATH__ instead of __x86_64__ when disabling x87 inline functions.


gcc-3.2 is unable to correctly compile x86_64 routines for llrint
since it gets redefined.  This is because gcc 3.2 does not set
__SSE2_MATH__ for x86_64, thus exposing the duplicate definition.

The correct fix ought to be to check for both __SSE2_MATH__ and
__x86_64__ and enable those bits only when neither are defined.

Tested fix with the reproducer for
409e00bd69b8d8dd74d7327085351d26769ea6fc as well as with gcc-3.2.

OK for 2.20?

Thanks,
Siddhesh

	[BZ #17262]
	* sysdeps/x86/fpu/bits/mathinline.h: Check both __SSE2_MATH__
	and __x86_64__ when disabling x87 inline functions.

diff --git a/sysdeps/x86/fpu/bits/mathinline.h b/sysdeps/x86/fpu/bits/mathinline.h
index 9c32e95..ee88b66 100644
--- a/sysdeps/x86/fpu/bits/mathinline.h
+++ b/sysdeps/x86/fpu/bits/mathinline.h
@@ -384,7 +384,10 @@ __END_NAMESPACE_C99
 # endif
 #endif
 
-#ifndef __SSE2_MATH__
+/* Disable x87 inlines when -fpmath=sse is passed and also when we're building
+   on x86_64.  Older gcc (gcc-3.2 for example) does not set __SSE2_MATH__
+   for x86_64.  */
+#if !defined __SSE2_MATH__ && !defined __x86_64__
 # if ((!defined __NO_MATH_INLINES || defined __LIBC_INTERNAL_MATH_INLINES) \
      && defined __OPTIMIZE__)
 
@@ -970,4 +973,4 @@ __inline_mathcode2 (__ieee754_atan2, __y, __x,
 		    return __value;)
 # endif
 
-#endif /* !__SSE2_MATH__ */
+#endif /* !__SSE2_MATH__ && !__x86_64__ */

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