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[PATCH] powerpc: fenvinline.h refactor


Hi,

Attached to this email is a patch to refactor fenvinline.h for power to include some __buitins when available. I also removed a weird asm constraint. I can't reproduce the warning described on the file and the test passed. Not sure why the put that constraint. I will appreciate any reviews.

Regard
>From dbeca754bcbc6c77b6157a2f818554db31bac2ba Mon Sep 17 00:00:00 2001
From: Rogerio Alves <rcardoso@linux.ibm.com>
Date: Thu, 23 Jan 2020 14:54:00 -0300
Subject: [PATCH v1] powerpc: Refactor fenvinline.h

This patch refactor fenviline.h replaces some statements for
builtins.

2020-01-22  Rogerio A. Cardoso  <rcardoso@linux.ibm.com>

	* sysdeps/unix/sysv/linux/powerpc/bits/fenvline.h:
    Replace expression by __builtin_popcount. Use
    __builtin_mtfsb[01] when avaliable. Remove weird i#*X
    asm constraint.
---
 sysdeps/powerpc/bits/fenvinline.h | 25 +++++++++++++++----------
 1 file changed, 15 insertions(+), 10 deletions(-)

diff --git a/sysdeps/powerpc/bits/fenvinline.h b/sysdeps/powerpc/bits/fenvinline.h
index 70689664e2..ae04ece189 100644
--- a/sysdeps/powerpc/bits/fenvinline.h
+++ b/sysdeps/powerpc/bits/fenvinline.h
@@ -15,7 +15,7 @@
    You should have received a copy of the GNU Lesser General Public
    License along with the GNU C Library; if not, see
    <https://www.gnu.org/licenses/>.  */
-
+#include <stdio.h>
 #if defined __GNUC__ && !defined _SOFT_FLOAT && !defined __NO_FPRS__
 
 /* Inline definitions for fegetround.  */
@@ -51,9 +51,16 @@
 # define fegetround() __fegetround ()
 
 # ifndef __NO_MATH_INLINES
-/* The weird 'i#*X' constraints on the following suppress a gcc
-   warning when __excepts is not a constant.  Otherwise, they mean the
-   same as just plain 'i'.  */
+
+/* Builtins to mtfsb0 and mtfsb1 was introduced on GCC 9.  */
+#  if !__GNUC_PREREQ(9, 0)
+
+#   define __builtin_mtfsb0(__b)					\
+   __asm__ __volatile__ ("mtfsb0 %0" : : "i" __b)
+
+#   define __builtin_mtfsb1(__b)					\
+   __asm__ __volatile__ ("mtfsb1 %0" : : "i" __b)
+#  endif
 
 #  if __GNUC_PREREQ(3, 4)
 
@@ -63,12 +70,11 @@
     int __e = __excepts;						      \
     int __ret;								      \
     if (__builtin_constant_p (__e)					      \
-        && (__e & (__e - 1)) == 0					      \
+        && (__builtin_popcount (__e) == 1)				      \
         && __e != FE_INVALID)						      \
       {									      \
 	if (__e != 0)							      \
-	  __asm__ __volatile__ ("mtfsb1 %0"				      \
-				: : "i#*X" (__builtin_clz (__e)));	      \
+	  __builtin_mtfsb1 ((__builtin_clz (__e)));			      \
         __ret = 0;							      \
       }									      \
     else								      \
@@ -82,12 +88,11 @@
     int __e = __excepts;						      \
     int __ret;								      \
     if (__builtin_constant_p (__e)					      \
-        && (__e & (__e - 1)) == 0					      \
+        && (__builtin_popcount (__e) == 1)				      \
         && __e != FE_INVALID)						      \
       {									      \
 	if (__e != 0)							      \
-	  __asm__ __volatile__ ("mtfsb0 %0"				      \
-				: : "i#*X" (__builtin_clz (__e)));	      \
+	  __builtin_mtfsb0 ((__builtin_clz (__e)));			      \
         __ret = 0;							      \
       }									      \
     else								      \
-- 
2.17.1


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