* [PATCH] Use fsqrt and fsqrts unconditionally on ppc64
@ 2006-01-20 16:00 Jakub Jelinek
0 siblings, 0 replies; only message in thread
From: Jakub Jelinek @ 2006-01-20 16:00 UTC (permalink / raw)
To: Ulrich Drepper, Roland McGrath, Steven Munroe; +Cc: Glibc hackers
Hi!
Any reason why fsqrt{,s} use is conditional even in 64-bit glibc?
sysdeps/powerpc/fpu/e_sqrt{,f}.c guards the insn use with:
/* If the CPU is 64-bit we can use the optional FP instructions we. */
if ((GLRO (dl_hwcap) & PPC_FEATURE_64) != 0)
and otherwise falls back to __slow_ieee754_sqrt{,f}. But in 64-bit
code, I'd say we can always assume the CPU is 64-bit and PPC_FEATURE_64
is set and get rid of an unneeded runtime memory load, masking and more
importantly quite large fallback routine.
2006-01-20 Jakub Jelinek <jakub@redhat.com>
* sysdeps/powerpc/powerpc64/fpu/e_sqrt.c: New file.
* sysdeps/powerpc/powerpc64/fpu/e_sqrtf.c: New file.
* sysdeps/powerpc/fpu/bits/mathinline.h (__CPU_HAS_FSQRT): Define.
(__ieee754_sqrt, __ieee754_sqrtf): Use it.
--- libc/sysdeps/powerpc/powerpc64/fpu/e_sqrt.c.jj 2006-01-20 16:36:49.000000000 +0100
+++ libc/sysdeps/powerpc/powerpc64/fpu/e_sqrt.c 2006-01-20 16:39:05.000000000 +0100
@@ -0,0 +1,29 @@
+/* Double-precision floating point square root.
+ Copyright (C) 1997, 2002, 2003, 2004, 2006 Free Software Foundation, Inc.
+ This file is part of the GNU C Library.
+
+ The GNU C Library is free software; you can redistribute it and/or
+ modify it under the terms of the GNU Lesser General Public
+ License as published by the Free Software Foundation; either
+ version 2.1 of the License, or (at your option) any later version.
+
+ The GNU C Library is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ Lesser General Public License for more details.
+
+ You should have received a copy of the GNU Lesser General Public
+ License along with the GNU C Library; if not, write to the Free
+ Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
+ 02111-1307 USA. */
+
+#include <math.h>
+#include <math_private.h>
+
+double
+__ieee754_sqrt (double x)
+{
+ double z;
+ __asm __volatile ("fsqrt %0,%1" : "=f" (z) : "f" (x));
+ return z;
+}
--- libc/sysdeps/powerpc/powerpc64/fpu/e_sqrtf.c.jj 2006-01-20 16:36:52.000000000 +0100
+++ libc/sysdeps/powerpc/powerpc64/fpu/e_sqrtf.c 2006-01-20 16:37:55.000000000 +0100
@@ -0,0 +1,29 @@
+/* Single-precision floating point square root.
+ Copyright (C) 1997, 2003, 2004, 2006 Free Software Foundation, Inc.
+ This file is part of the GNU C Library.
+
+ The GNU C Library is free software; you can redistribute it and/or
+ modify it under the terms of the GNU Lesser General Public
+ License as published by the Free Software Foundation; either
+ version 2.1 of the License, or (at your option) any later version.
+
+ The GNU C Library is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ Lesser General Public License for more details.
+
+ You should have received a copy of the GNU Lesser General Public
+ License along with the GNU C Library; if not, write to the Free
+ Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
+ 02111-1307 USA. */
+
+#include <math.h>
+#include <math_private.h>
+
+float
+__ieee754_sqrtf (float x)
+{
+ double z;
+ __asm ("fsqrts %0,%1" : "=f" (z) : "f" (x));
+ return z;
+}
--- libc/sysdeps/powerpc/fpu/bits/mathinline.h.jj 2004-10-01 12:05:04.000000000 +0200
+++ libc/sysdeps/powerpc/fpu/bits/mathinline.h 2006-01-20 16:45:16.000000000 +0100
@@ -1,5 +1,5 @@
/* Inline math functions for powerpc.
- Copyright (C) 1995, 1996, 1997, 1998, 1999, 2000, 2004
+ Copyright (C) 1995, 1996, 1997, 1998, 1999, 2000, 2004, 2006
Free Software Foundation, Inc.
This file is part of the GNU C Library.
@@ -123,12 +123,18 @@ __NTH (fdimf (float __x, float __y))
#endif /* !__NO_MATH_INLINES && __OPTIMIZE__ */
/* This code is used internally in the GNU libc. */
-# ifdef __LIBC_INTERNAL_MATH_INLINES
+#ifdef __LIBC_INTERNAL_MATH_INLINES
#include <sysdep.h>
#include <ldsodefs.h>
#include <dl-procinfo.h>
+# if __WORDSIZE == 64
+# define __CPU_HAS_FSQRT 1
+# else
+# define __CPU_HAS_FSQRT ((GLRO(dl_hwcap) & PPC_FEATURE_64) != 0)
+# endif
+
extern double __slow_ieee754_sqrt (double);
__MATH_INLINE double
__NTH (__ieee754_sqrt (double __x))
@@ -136,7 +142,7 @@ __NTH (__ieee754_sqrt (double __x))
double __z;
/* If the CPU is 64-bit we can use the optional FP instructions we. */
- if ((GLRO(dl_hwcap) & PPC_FEATURE_64) != 0)
+ if (__CPU_HAS_FSQRT)
{
/* Volatile is required to prevent the compiler from moving the
fsqrt instruction above the branch. */
@@ -158,7 +164,7 @@ __NTH (__ieee754_sqrtf (float __x))
float __z;
/* If the CPU is 64-bit we can use the optional FP instructions we. */
- if ((GLRO(dl_hwcap) & PPC_FEATURE_64) != 0)
+ if (__CPU_HAS_FSQRT)
{
/* Volatile is required to prevent the compiler from moving the
fsqrts instruction above the branch. */
@@ -172,5 +178,5 @@ __NTH (__ieee754_sqrtf (float __x))
return __z;
}
-# endif /* __LIBC_INTERNAL_MATH_INLINES */
+#endif /* __LIBC_INTERNAL_MATH_INLINES */
#endif /* __GNUC__ && !_SOFT_FLOAT */
Jakub
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2006-01-20 16:00 [PATCH] Use fsqrt and fsqrts unconditionally on ppc64 Jakub Jelinek
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