From 1c252f0e7e5d78695f19450aa7c470bab445aa8e Mon Sep 17 00:00:00 2001 From: Matheus Castanho Date: Tue, 3 Mar 2020 15:20:38 -0300 Subject: [PATCH] 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 --- sysdeps/powerpc/bits/fenvinline.h | 4 ++-- 1 file 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))); \ -- 2.43.5