From cb5c057c87240a9534f8e0d9b7ff2560082f6218 Mon Sep 17 00:00:00 2001 From: Szabolcs Nagy Date: Sat, 11 Apr 2015 00:35:07 +0000 Subject: [PATCH] math: fix pow(+-0,-inf) not to raise divbyzero flag this reverts the commit f29fea00b5bc72d4b8abccba2bb1e312684d1fce which was based on a bug in C99 and POSIX and did not match IEEE-754 http://www.open-std.org/jtc1/sc22/wg14/www/docs/n1515.pdf --- src/math/pow.c | 2 +- src/math/powf.c | 2 +- src/math/powl.c | 2 +- 3 files changed, 3 insertions(+), 3 deletions(-) diff --git a/src/math/pow.c b/src/math/pow.c index 82f684bd..b66f632d 100644 --- a/src/math/pow.c +++ b/src/math/pow.c @@ -143,7 +143,7 @@ double pow(double x, double y) return 1.0; else if (ix >= 0x3ff00000) /* (|x|>1)**+-inf = inf,0 */ return hy >= 0 ? y : 0.0; - else if ((ix|lx) != 0) /* (|x|<1)**+-inf = 0,inf if x!=0 */ + else /* (|x|<1)**+-inf = 0,inf */ return hy >= 0 ? 0.0 : -y; } if (iy == 0x3ff00000) { /* y is +-1 */ diff --git a/src/math/powf.c b/src/math/powf.c index 59baf6f3..427c8965 100644 --- a/src/math/powf.c +++ b/src/math/powf.c @@ -90,7 +90,7 @@ float powf(float x, float y) return 1.0f; else if (ix > 0x3f800000) /* (|x|>1)**+-inf = inf,0 */ return hy >= 0 ? y : 0.0f; - else if (ix != 0) /* (|x|<1)**+-inf = 0,inf if x!=0 */ + else /* (|x|<1)**+-inf = 0,inf */ return hy >= 0 ? 0.0f: -y; } if (iy == 0x3f800000) /* y is +-1 */ diff --git a/src/math/powl.c b/src/math/powl.c index a765706d..5b6da07b 100644 --- a/src/math/powl.c +++ b/src/math/powl.c @@ -227,7 +227,7 @@ long double powl(long double x, long double y) if (y <= -LDBL_MAX) { if (x > 1.0 || x < -1.0) return 0.0; - if (x != 0.0) + if (x != 0.0 || y == -INFINITY) return INFINITY; } if (x >= LDBL_MAX) { -- 2.25.1