From a84e78c8b3c4de94b488fdc5321f71feeb99358f Mon Sep 17 00:00:00 2001 From: Joseph Myers Date: Wed, 2 Apr 2014 17:41:02 +0000 Subject: Fix catan, catanh, __ieee754_logf in round-downward mode (bug 16799, bug 16800). This patch fixes incorrect results from catan and catanh of certain special inputs in round-downward mode (bug 16799), and incorrect results of __ieee754_logf (+/-0) in round-downward mode (bug 16800) that show up through catan/catanh when tested in all rounding modes, but not directly in the testing for logf because the bug gets hidden by the wrappers. Both bugs involve a zero that should be +0 being -0 instead: one computed as (1-x)*(1+x) in the catan/catanh case, and one as (x-x) in the logf case. The fixes ensure positive zero is used. Testing of catan and catanh in all rounding modes is duly enabled. I expect there are various other bugs in special cases in __ieee754_* functions that are normally hidden by the wrappers but would show up for testing with -lieee (or in future with -fno-math-errno if we replace -lieee and _LIB_VERSION with compile-time redirection to new *_noerrno symbol names). Tested x86_64 and x86 and ulps updated accordingly. [BZ #16799] [BZ #16800] * math/s_catan.c (__catan): Avoid passing -0 denominator to atan2 with 0 numerator. * math/s_catanf.c (__catanf): Likewise. * math/s_catanh.c (__catanh): Likewise. * math/s_catanhf.c (__catanhf): Likewise. * math/s_catanhl.c (__catanhl): Likewise. * math/s_catanl.c (__catanl): Likewise. * sysdeps/ieee754/flt-32/e_logf.c (__ieee754_logf): Always divide by positive zero when computing -Inf result. * math/libm-test.inc (catan_test): Use ALL_RM_TEST. (catanh_test): Likewise. * sysdeps/i386/fpu/libm-test-ulps: Update. * sysdeps/x86_64/fpu/libm-test-ulps: Likewise. --- math/libm-test.inc | 8 ++------ math/s_catan.c | 6 +++++- math/s_catanf.c | 6 +++++- math/s_catanh.c | 6 +++++- math/s_catanhf.c | 6 +++++- math/s_catanhl.c | 6 +++++- math/s_catanl.c | 6 +++++- 7 files changed, 32 insertions(+), 12 deletions(-) (limited to 'math') diff --git a/math/libm-test.inc b/math/libm-test.inc index c6279e75a9..5e6789f9fb 100644 --- a/math/libm-test.inc +++ b/math/libm-test.inc @@ -5239,9 +5239,7 @@ static const struct test_c_c_data catan_test_data[] = static void catan_test (void) { - START (catan, 0); - RUN_TEST_LOOP_c_c (catan, catan_test_data, ); - END_COMPLEX; + ALL_RM_TEST (catan, 0, catan_test_data, RUN_TEST_LOOP_c_c, END_COMPLEX); } static const struct test_c_c_data catanh_test_data[] = @@ -5746,9 +5744,7 @@ static const struct test_c_c_data catanh_test_data[] = static void catanh_test (void) { - START (catanh, 0); - RUN_TEST_LOOP_c_c (catanh, catanh_test_data, ); - END_COMPLEX; + ALL_RM_TEST (catanh, 0, catanh_test_data, RUN_TEST_LOOP_c_c, END_COMPLEX); } static const struct test_f_f_data cbrt_test_data[] = diff --git a/math/s_catan.c b/math/s_catan.c index d6552d8b7c..0cfa92434a 100644 --- a/math/s_catan.c +++ b/math/s_catan.c @@ -89,7 +89,11 @@ __catan (__complex__ double x) } if (absy < DBL_EPSILON / 2.0) - den = (1.0 - absx) * (1.0 + absx); + { + den = (1.0 - absx) * (1.0 + absx); + if (den == -0.0) + den = 0.0; + } else if (absx >= 1.0) den = (1.0 - absx) * (1.0 + absx) - absy * absy; else if (absx >= 0.75 || absy >= 0.5) diff --git a/math/s_catanf.c b/math/s_catanf.c index 41e419d8b0..b478684652 100644 --- a/math/s_catanf.c +++ b/math/s_catanf.c @@ -90,7 +90,11 @@ __catanf (__complex__ float x) } if (absy < FLT_EPSILON / 2.0f) - den = (1.0f - absx) * (1.0f + absx); + { + den = (1.0f - absx) * (1.0f + absx); + if (den == -0.0f) + den = 0.0f; + } else if (absx >= 1.0f) den = (1.0f - absx) * (1.0f + absx) - absy * absy; else if (absx >= 0.75f || absy >= 0.5f) diff --git a/math/s_catanh.c b/math/s_catanh.c index 2ba1298bb6..7ef9142b0d 100644 --- a/math/s_catanh.c +++ b/math/s_catanh.c @@ -110,7 +110,11 @@ __catanh (__complex__ double x) } if (absy < DBL_EPSILON / 2.0) - den = (1.0 - absx) * (1.0 + absx); + { + den = (1.0 - absx) * (1.0 + absx); + if (den == -0.0) + den = 0.0; + } else if (absx >= 1.0) den = (1.0 - absx) * (1.0 + absx) - absy * absy; else if (absx >= 0.75 || absy >= 0.5) diff --git a/math/s_catanhf.c b/math/s_catanhf.c index 0ee69a5ba0..0e55aff16c 100644 --- a/math/s_catanhf.c +++ b/math/s_catanhf.c @@ -112,7 +112,11 @@ __catanhf (__complex__ float x) } if (absy < FLT_EPSILON / 2.0f) - den = (1.0f - absx) * (1.0f + absx); + { + den = (1.0f - absx) * (1.0f + absx); + if (den == -0.0f) + den = 0.0f; + } else if (absx >= 1.0f) den = (1.0f - absx) * (1.0f + absx) - absy * absy; else if (absx >= 0.75f || absy >= 0.5f) diff --git a/math/s_catanhl.c b/math/s_catanhl.c index 537bb3e28d..6410afec31 100644 --- a/math/s_catanhl.c +++ b/math/s_catanhl.c @@ -118,7 +118,11 @@ __catanhl (__complex__ long double x) } if (absy < LDBL_EPSILON / 2.0L) - den = (1.0L - absx) * (1.0L + absx); + { + den = (1.0L - absx) * (1.0L + absx); + if (den == -0.0L) + den = 0.0L; + } else if (absx >= 1.0L) den = (1.0L - absx) * (1.0L + absx) - absy * absy; else if (absx >= 0.75L || absy >= 0.5L) diff --git a/math/s_catanl.c b/math/s_catanl.c index cea9282a54..dd01d16dcd 100644 --- a/math/s_catanl.c +++ b/math/s_catanl.c @@ -97,7 +97,11 @@ __catanl (__complex__ long double x) } if (absy < LDBL_EPSILON / 2.0L) - den = (1.0L - absx) * (1.0L + absx); + { + den = (1.0L - absx) * (1.0L + absx); + if (den == -0.0L) + den = 0.0L; + } else if (absx >= 1.0L) den = (1.0L - absx) * (1.0L + absx) - absy * absy; else if (absx >= 0.75L || absy >= 0.5L) -- cgit v1.2.1