From 18b4e0e5187f7e2076661e53747977f21dabedff Mon Sep 17 00:00:00 2001 From: Fabian Schriever Date: Tue, 10 Mar 2020 11:24:12 +0100 Subject: Fix error in fdim/f for infinities The comparison c == FP_INFINITE causes the function to return +inf as it expects x = +inf to always be larger than y. This shortcut causes several issues as it also returns +inf for the following cases: - fdim(+inf, +inf), expected (as per C99): +0.0 - fdim(-inf, any non NaN), expected: +0.0 I don't see a reason to keep the comparison as all the infinity cases return the correct result using just the ternary operation. --- newlib/libm/common/s_fdim.c | 5 +---- newlib/libm/common/sf_fdim.c | 5 +---- 2 files changed, 2 insertions(+), 8 deletions(-) diff --git a/newlib/libm/common/s_fdim.c b/newlib/libm/common/s_fdim.c index 73a0279..61a4908 100644 --- a/newlib/libm/common/s_fdim.c +++ b/newlib/libm/common/s_fdim.c @@ -49,11 +49,8 @@ ANSI C, POSIX. double y; #endif { - int c = __fpclassifyd(x); - if (c == FP_NAN) return(x); + if (__fpclassifyd(x) == FP_NAN) return(x); if (__fpclassifyd(y) == FP_NAN) return(y); - if (c == FP_INFINITE) - return HUGE_VAL; return x > y ? x - y : 0.0; } diff --git a/newlib/libm/common/sf_fdim.c b/newlib/libm/common/sf_fdim.c index fe34909..8fee570 100644 --- a/newlib/libm/common/sf_fdim.c +++ b/newlib/libm/common/sf_fdim.c @@ -14,11 +14,8 @@ float y; #endif { - int c = __fpclassifyf(x); - if (c == FP_NAN) return(x); + if (__fpclassifyf(x) == FP_NAN) return(x); if (__fpclassifyf(y) == FP_NAN) return(y); - if (c == FP_INFINITE) - return HUGE_VALF; return x > y ? x - y : 0.0; } -- cgit v1.1