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authorMatheus Castanho <msc@linux.ibm.com>2020-03-03 15:20:38 -0300
committerTulio Magno Quites Machado Filho <tuliom@linux.ibm.com>2020-03-06 11:10:12 -0300
commit1c252f0e7e5d78695f19450aa7c470bab445aa8e (patch)
treeff03c7d2393a6eae4cd7029ab44078508e94579e /sysdeps/powerpc/bits
parentaf09e5e5d9ec3ca20891e61a6922eac984fcbdc4 (diff)
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powerpc: Fix feraiseexcept and feclearexcept macros
A recent change to fenvinline.h modified the check if __e is a
a power of 2 inside feraiseexcept and feclearexcept macros.  It
introduced the use of the powerof2 macro but also removed the
if statement checking whether __e != 0 before issuing an mtfsb*
instruction.  This is problematic because powerof2 (0) evaluates
to 1 and without the removed if __e is allowed to be 0 when
__builtin_clz is called.  In that case the value 32 is passed
to __MTFSB*, which is invalid.

This commit uses __builtin_popcount instead of powerof2 to fix this
issue and avoid the extra check for __e != 0.  This was the approach
used by the initial versions of that previous patch.

Reviewed-by: Tulio Magno Quites Machado Filho <tuliom@linux.ibm.com>
Diffstat (limited to 'sysdeps/powerpc/bits')
-rw-r--r--sysdeps/powerpc/bits/fenvinline.h4
1 files changed, 2 insertions, 2 deletions
diff --git a/sysdeps/powerpc/bits/fenvinline.h b/sysdeps/powerpc/bits/fenvinline.h
index 89ea38a4f8..f2d095a72f 100644
--- a/sysdeps/powerpc/bits/fenvinline.h
+++ b/sysdeps/powerpc/bits/fenvinline.h
@@ -75,7 +75,7 @@
     int __e = __excepts;						      \
     int __ret = 0;							      \
     if (__builtin_constant_p (__e)					      \
-        && powerof2 (__e)						      \
+        && __builtin_popcount (__e) == 1				      \
         && __e != FE_INVALID)						      \
       {									      \
 	__MTFSB1 ((__builtin_clz (__e)));				      \
@@ -91,7 +91,7 @@
     int __e = __excepts;						      \
     int __ret = 0;							      \
     if (__builtin_constant_p (__e)					      \
-        && powerof2 (__e)						      \
+        && __builtin_popcount (__e) == 1				      \
         && __e != FE_INVALID)						      \
       {									      \
 	__MTFSB0 ((__builtin_clz (__e)));				      \