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Add volatiles for x86-64 bits/mathinline.h

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[BZ #14053]
GCC 4.7 might remove consecutive calls to e.g. lrintf since
the assembler instructions are the same and GCC does not know
that the result is different depending on the rounding mode.  For
SSE instructions, the control register is not available so there
is no way to inform GCC about this. Therefore the asms are marked
as volatile.
This commit is contained in:
Andreas Jaeger 2012-05-09 20:17:21 +02:00
parent 91d8d69ec6
commit bdd74070cc
3 changed files with 54 additions and 9 deletions
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13
ChangeLog
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@ -1,3 +1,16 @@
2012-05-09 Andreas Jaeger <aj@suse.de>
[BZ #14053]
* sysdeps/x86_64/fpu/bits/mathinline.h (lrintf): Add __volatile
to asm.
(lrint): Likewise.
(llrintf): Likewise.
(llrint): Likewise.
(rint): Likewise.
(rintf): Likewise.
(nearbyint): Likewise.
(nearbyintf): Likewise.
2012-05-09 Andreas Jaeger <aj@suse.de>
Pedro Alves <palves@redhat.com>

2
NEWS
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@ -24,7 +24,7 @@ Version 2.16
13895, 13908, 13910, 13911, 13912, 13913, 13914, 13915, 13916, 13917,
13918, 13919, 13920, 13921, 13922, 13923, 13924, 13926, 13927, 13928,
13938, 13941, 13942, 13963, 13967, 13970, 13973, 13979, 13983, 14027,
14033, 14034, 14040, 14049, 14055, 14064, 14080, 14083
14033, 14034, 14040, 14049, 14053, 14055, 14064, 14080, 14083
* ISO C11 support:

48
sysdeps/x86_64/fpu/bits/mathinline.h
View File

@ -79,7 +79,11 @@ __MATH_INLINE long int
__NTH (lrintf (float __x))
{
long int __res;
__asm ("cvtss2si %1, %0" : "=r" (__res) : "xm" (__x));
/* Mark as volatile since the result is dependend on the state of
the SSE control register (the rounding mode). Otherwise GCC might
remove these assembler instructions since it does not know about
the rounding mode change and cannot currently be told. */
__asm __volatile__ ("cvtss2si %1, %0" : "=r" (__res) : "xm" (__x));
return __res;
}
# endif
@ -88,7 +92,11 @@ __MATH_INLINE long int
__NTH (lrint (double __x))
{
long int __res;
__asm ("cvtsd2si %1, %0" : "=r" (__res) : "xm" (__x));
/* Mark as volatile since the result is dependend on the state of
the SSE control register (the rounding mode). Otherwise GCC might
remove these assembler instructions since it does not know about
the rounding mode change and cannot currently be told. */
__asm __volatile__ ("cvtsd2si %1, %0" : "=r" (__res) : "xm" (__x));
return __res;
}
# endif
@ -97,14 +105,22 @@ __MATH_INLINE long long int
__NTH (llrintf (float __x))
{
long long int __res;
__asm ("cvtss2si %1, %0" : "=r" (__res) : "xm" (__x));
/* Mark as volatile since the result is dependend on the state of
the SSE control register (the rounding mode). Otherwise GCC might
remove these assembler instructions since it does not know about
the rounding mode change and cannot currently be told. */
__asm __volatile__ ("cvtss2si %1, %0" : "=r" (__res) : "xm" (__x));
return __res;
}
__MATH_INLINE long long int
__NTH (llrint (double __x))
{
long long int __res;
__asm ("cvtsd2si %1, %0" : "=r" (__res) : "xm" (__x));
/* Mark as volatile since the result is dependend on the state of
the SSE control register (the rounding mode). Otherwise GCC might
remove these assembler instructions since it does not know about
the rounding mode change and cannot currently be told. */
__asm __volatile__ ("cvtsd2si %1, %0" : "=r" (__res) : "xm" (__x));
return __res;
}
# endif
@ -176,14 +192,22 @@ __MATH_INLINE double
__NTH (rint (double __x))
{
double __res;
__asm ("roundsd $4, %1, %0" : "=x" (__res) : "xm" (__x));
/* Mark as volatile since the result is dependend on the state of
the SSE control register (the rounding mode). Otherwise GCC might
remove these assembler instructions since it does not know about
the rounding mode change and cannot currently be told. */
__asm __volatile__ ("roundsd $4, %1, %0" : "=x" (__res) : "xm" (__x));
return __res;
}
__MATH_INLINE float
__NTH (rintf (float __x))
{
float __res;
__asm ("roundss $4, %1, %0" : "=x" (__res) : "xm" (__x));
/* Mark as volatile since the result is dependend on the state of
the SSE control register (the rounding mode). Otherwise GCC might
remove these assembler instructions since it does not know about
the rounding mode change and cannot currently be told. */
__asm __volatile__ ("roundss $4, %1, %0" : "=x" (__res) : "xm" (__x));
return __res;
}
@ -193,14 +217,22 @@ __MATH_INLINE double
__NTH (nearbyint (double __x))
{
double __res;
__asm ("roundsd $0xc, %1, %0" : "=x" (__res) : "xm" (__x));
/* Mark as volatile since the result is dependend on the state of
the SSE control register (the rounding mode). Otherwise GCC might
remove these assembler instructions since it does not know about
the rounding mode change and cannot currently be told. */
__asm __volatile__ ("roundsd $0xc, %1, %0" : "=x" (__res) : "xm" (__x));
return __res;
}
__MATH_INLINE float
__NTH (nearbyintf (float __x))
{
float __res;
__asm ("roundss $0xc, %1, %0" : "=x" (__res) : "xm" (__x));
/* Mark as volatile since the result is dependend on the state of
the SSE control register (the rounding mode). Otherwise GCC might
remove these assembler instructions since it does not know about
the rounding mode change and cannot currently be told. */
__asm __volatile__ ("roundss $0xc, %1, %0" : "=x" (__res) : "xm" (__x));
return __res;
}
# endif