From 8c6c9236361fbc077769673c259828216403bc33 Mon Sep 17 00:00:00 2001 From: Joseph Myers Date: Wed, 30 Sep 2015 21:44:42 +0000 Subject: Fix i386 acosh (-qNaN) spurious "invalid" exception. The i386 versions of acoshf and acosh raise a spurious "invalid" exception for an argument that is a quiet NaN with the sign bit set. The integer arithmetic to detect arguments < 1 also detects -NaN, and then the computation 0 / 0 in that case raises the exception. This patch fixes this by using (x - x) / (x - x) as the computation in that case instead, which will always raise the exception for non-NaN arguments reaching that code, but not for quiet NaN arguments. Tested for x86_64 and x86. [BZ #19032] * sysdeps/i386/fpu/e_acosh.S (__ieee754_acosh): For arguments < 1, compute result as (x - x) / (x - x) not as 0 / 0. * sysdeps/i386/fpu/e_acoshf.S (__ieee754_acoshf): Likewise. * math/libm-test.inc (acosh_test_data): Add another test of acosh. --- math/libm-test.inc | 1 + 1 file changed, 1 insertion(+) (limited to 'math') diff --git a/math/libm-test.inc b/math/libm-test.inc index 744c66dbb1..8615957600 100644 --- a/math/libm-test.inc +++ b/math/libm-test.inc @@ -1790,6 +1790,7 @@ static const struct test_f_f_data acosh_test_data[] = TEST_f_f (acosh, plus_infty, plus_infty, ERRNO_UNCHANGED), TEST_f_f (acosh, minus_infty, qnan_value, INVALID_EXCEPTION|ERRNO_EDOM), TEST_f_f (acosh, qnan_value, qnan_value, NO_INEXACT_EXCEPTION|ERRNO_UNCHANGED), + TEST_f_f (acosh, -qnan_value, qnan_value, NO_INEXACT_EXCEPTION|ERRNO_UNCHANGED), /* x < 1: */ TEST_f_f (acosh, 0.75L, qnan_value, INVALID_EXCEPTION|ERRNO_EDOM), -- cgit v1.2.3