powerpc: Fix fsqrt build in libm [BZ#16576]

Some powerpc64 processors (e5500 core for instance) does not provide the
fsqrt instruction, however current check to use in math_private.h is
__WORDSIZE and _ARCH_PWR4 (ISA 2.02).  This is patch change it to use
the compiler flag _ARCH_PPCSQ (which is the same condition GCC uses to
decide whether to generate fsqrt instruction).

It fixes BZ#16576.

5 files changed, 24 insertions, 102 deletions

diff --git a/sysdeps/powerpc/fpu/e_sqrt.c b/sysdeps/powerpc/fpu/e_sqrt.c
index ba77ae5a9f..0934faa5fe 100644
--- a/sysdeps/powerpc/fpu/e_sqrt.c
+++ b/sysdeps/powerpc/fpu/e_sqrt.c
@@ -24,6 +24,7 @@
 #include <sysdep.h>
 #include <ldsodefs.h>
 
+#ifndef _ARCH_PPCSQ
 static const double almost_half = 0.5000000000000001;	/* 0.5 + 2^-53 */
 static const ieee_float_shape_type a_nan = {.word = 0x7fc00000 };
 static const ieee_float_shape_type a_inf = {.word = 0x7f800000 };
@@ -152,6 +153,7 @@ __slow_ieee754_sqrt (double x)
     }
   return f_wash (x);
 }
+#endif /* _ARCH_PPCSQ  */
 
 #undef __ieee754_sqrt
 double
@@ -159,16 +161,11 @@ __ieee754_sqrt (double x)
 {
   double z;
 
-  /* If the CPU is 64-bit we can use the optional FP instructions.  */
-  if (__CPU_HAS_FSQRT)
-    {
-      /* Volatile is required to prevent the compiler from moving the
-	 fsqrt instruction above the branch.  */
-      __asm __volatile ("	fsqrt	%0,%1\n"
-				:"=f" (z):"f" (x));
-    }
-  else
-    z = __slow_ieee754_sqrt (x);
+#ifdef _ARCH_PPCSQ
+  asm ("fsqrt %0,%1\n" :"=f" (z):"f" (x));
+#else
+  z = __slow_ieee754_sqrt (x);
+#endif
 
   return z;
 }
diff --git a/sysdeps/powerpc/fpu/e_sqrtf.c b/sysdeps/powerpc/fpu/e_sqrtf.c
index 5cf47f707e..034b6f58ca 100644
--- a/sysdeps/powerpc/fpu/e_sqrtf.c
+++ b/sysdeps/powerpc/fpu/e_sqrtf.c
@@ -24,6 +24,7 @@
 #include <sysdep.h>
 #include <ldsodefs.h>
 
+#ifndef _ARCH_PPCSQ
 static const float almost_half = 0.50000006;	/* 0.5 + 2^-24 */
 static const ieee_float_shape_type a_nan = {.word = 0x7fc00000 };
 static const ieee_float_shape_type a_inf = {.word = 0x7f800000 };
@@ -128,6 +129,7 @@ __slow_ieee754_sqrtf (float x)
     }
   return f_washf (x);
 }
+#endif /* _ARCH_PPCSQ  */
 
 #undef __ieee754_sqrtf
 float
@@ -135,16 +137,11 @@ __ieee754_sqrtf (float x)
 {
   double z;
 
-  /* If the CPU is 64-bit we can use the optional FP instructions.  */
-  if (__CPU_HAS_FSQRT)
-    {
-      /* Volatile is required to prevent the compiler from moving the
-	 fsqrt instruction above the branch.  */
-      __asm __volatile ("	fsqrts	%0,%1\n"
-				:"=f" (z):"f" (x));
-    }
-  else
-    z = __slow_ieee754_sqrtf (x);
+#ifdef _ARCH_PPCSQ
+  asm ("fsqrts	%0,%1\n" :"=f" (z):"f" (x));
+#else
+  z = __slow_ieee754_sqrtf (x);
+#endif
 
   return z;
 }
diff --git a/sysdeps/powerpc/fpu/math_private.h b/sysdeps/powerpc/fpu/math_private.h
index 6631535e82..37e7456bac 100644
--- a/sysdeps/powerpc/fpu/math_private.h
+++ b/sysdeps/powerpc/fpu/math_private.h
@@ -25,26 +25,17 @@
 #include <fenv_private.h>
 #include_next <math_private.h>
 
-# if __WORDSIZE == 64 || defined _ARCH_PWR4
-#  define __CPU_HAS_FSQRT 1
-# else
-#  define __CPU_HAS_FSQRT ((GLRO(dl_hwcap) & PPC_FEATURE_64) != 0)
-# endif
-
 extern double __slow_ieee754_sqrt (double);
 extern __always_inline double
 __ieee754_sqrt (double __x)
 {
   double __z;
 
-  if (__CPU_HAS_FSQRT)
-    {
-      /* Volatile is required to prevent the compiler from moving the
-         fsqrt instruction above the branch.  */
-      __asm __volatile ("fsqrt	%0,%1" : "=f" (__z) : "f" (__x));
-    }
-  else
-     __z = __slow_ieee754_sqrt(__x);
+#ifdef _ARCH_PPCSQ
+   asm ("fsqrt	%0,%1" : "=f" (__z) : "f" (__x));
+#else
+   __z = __slow_ieee754_sqrt(__x);
+#endif
 
   return __z;
 }
@@ -55,14 +46,11 @@ __ieee754_sqrtf (float __x)
 {
   float __z;
 
-  if (__CPU_HAS_FSQRT)
-    {
-      /* Volatile is required to prevent the compiler from moving the
-         fsqrts instruction above the branch.  */
-      __asm __volatile ("fsqrts	%0,%1" : "=f" (__z) : "f" (__x));
-    }
-  else
-     __z = __slow_ieee754_sqrtf(__x);
+#ifdef _ARCH_PPCSQ
+  asm ("fsqrts	%0,%1" : "=f" (__z) : "f" (__x));
+#else
+   __z = __slow_ieee754_sqrtf(__x);
+#endif
 
   return __z;
 }
diff --git a/sysdeps/powerpc/powerpc64/fpu/e_sqrt.c b/sysdeps/powerpc/powerpc64/fpu/e_sqrt.c
deleted file mode 100644
index 796388e776..0000000000
--- a/sysdeps/powerpc/powerpc64/fpu/e_sqrt.c
+++ /dev/null
@@ -1,30 +0,0 @@
-/* Double-precision floating point square root.
-   Copyright (C) 1997-2015 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, see
-   <http://www.gnu.org/licenses/>.  */
-
-#include <math.h>
-#include <math_private.h>
-
-#undef __ieee754_sqrt
-double
-__ieee754_sqrt (double x)
-{
-  double z;
-  __asm __volatile ("fsqrt %0,%1" : "=f" (z) : "f" (x));
-  return z;
-}
-strong_alias (__ieee754_sqrt, __sqrt_finite)
diff --git a/sysdeps/powerpc/powerpc64/fpu/e_sqrtf.c b/sysdeps/powerpc/powerpc64/fpu/e_sqrtf.c
deleted file mode 100644
index 5502525d4d..0000000000
--- a/sysdeps/powerpc/powerpc64/fpu/e_sqrtf.c
+++ /dev/null
@@ -1,30 +0,0 @@
-/* Single-precision floating point square root.
-   Copyright (C) 1997-2015 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, see
-   <http://www.gnu.org/licenses/>.  */
-
-#include <math.h>
-#include <math_private.h>
-
-#undef __ieee754_sqrtf
-float
-__ieee754_sqrtf (float x)
-{
-  double z;
-  __asm ("fsqrts %0,%1" : "=f" (z) : "f" (x));
-  return z;
-}
-strong_alias (__ieee754_sqrtf, __sqrtf_finite)