From b72592e75fdecb34e2ac5f931730409a1fb68e8a Mon Sep 17 00:00:00 2001 From: Joseph Myers Date: Fri, 23 May 2014 12:07:50 +0000 Subject: Fix log10 (1) in round-downward mode (bug 16977). As with various other issues of this kind, bug 16977 is log10 (1) wrongly returning -0 rather than +0 in round-downward mode because of an implementation effectively in terms of log1p (x - 1). This patch fixes the issue in the same way used for log. Tested x86_64 and x86 and ulps updated accordingly. Also tested for mips64 to confirm a fix was needed for ldbl-128 and to validate that fix (also applied to ldbl-128ibm since that version of logl is essentially the same as the ldbl-128 one). [BZ #16977] * sysdeps/i386/fpu/e_log10.S (__ieee754_log10): Take absolute value when x - 1 is zero. * sysdeps/i386/fpu/e_log10f.S (__ieee754_log10f): Likewise. * sysdeps/i386/fpu/e_log10l.S (__ieee754_log10l): Likewise. * sysdeps/ieee754/ldbl-128/e_log10l.c (__ieee754_log10l): Return 0.0L for an argument of 1.0L. * sysdeps/ieee754/ldbl-128ibm/e_log10l.c (__ieee754_log10l): Likewise. * sysdeps/x86_64/fpu/e_log10l.S (__ieee754_log10l): Take absolute value when x - 1 is zero. * math/libm-test.inc (log10_test): Use ALL_RM_TEST. * sysdeps/i386/fpu/libm-test-ulps: Update. * sysdeps/x86_64/fpu/libm-test-ulps: Likewise. --- math/libm-test.inc | 4 +--- 1 file changed, 1 insertion(+), 3 deletions(-) (limited to 'math') diff --git a/math/libm-test.inc b/math/libm-test.inc index de7bc8a..0d467a2 100644 --- a/math/libm-test.inc +++ b/math/libm-test.inc @@ -7798,9 +7798,7 @@ static const struct test_f_f_data log10_test_data[] = static void log10_test (void) { - START (log10, 0); - RUN_TEST_LOOP_f_f (log10, log10_test_data, ); - END; + ALL_RM_TEST (log10, 0, log10_test_data, RUN_TEST_LOOP_f_f, END); } -- cgit v1.1