From 5244527da1bfa751492e146d3e6ae128c59bfcc4 Mon Sep 17 00:00:00 2001 From: Joseph Myers Date: Wed, 6 Dec 2017 21:35:20 +0000 Subject: [PATCH] Make cacosh (0 + iNaN) return NaN + i pi/2 (bug 22561, DR#471). As per C11 DR#471 (adjusted resolution accepted for C17), cacosh (0 + iNaN) should return NaN +/- i pi/2, not NaN + iNaN. This patch fixes the code accordingly. The test has hardcoded the result with positive sign of the imaginary part (with an associated comment), since the unspecified sign for a result other than 0 or infinity isn't currently supported by the test infrastructure. Tested for x86_64. [BZ #22561] * math/s_cacosh_template.c (M_DECL_FUNC (__cacosh)): Use pi/2 for real part of result for argument 0 + i * NaN. * math/libm-test-cacosh.inc (cacosh_test_data): Update expected results for tests of 0 + i * NaN. --- ChangeLog | 8 ++++++++ math/libm-test-cacosh.inc | 9 +++++++-- math/s_cacosh_template.c | 5 ++++- 3 files changed, 19 insertions(+), 3 deletions(-) diff --git a/ChangeLog b/ChangeLog index 9a57c30..b81d994 100644 --- a/ChangeLog +++ b/ChangeLog @@ -1,3 +1,11 @@ +2017-12-06 Joseph Myers + + [BZ #22561] + * math/s_cacosh_template.c (M_DECL_FUNC (__cacosh)): Use pi/2 for + real part of result for argument 0 + i * NaN. + * math/libm-test-cacosh.inc (cacosh_test_data): Update expected + results for tests of 0 + i * NaN. + 2017-12-06 Adhemerval Zanella * sysdeps/alpha/fpu/libm-test-ulps: Update. diff --git a/math/libm-test-cacosh.inc b/math/libm-test-cacosh.inc index 518cb29..db700b9 100644 --- a/math/libm-test-cacosh.inc +++ b/math/libm-test-cacosh.inc @@ -46,8 +46,13 @@ static const struct test_c_c_data cacosh_test_data[] = TEST_c_c (cacosh, plus_infty, qnan_value, plus_infty, qnan_value), TEST_c_c (cacosh, minus_infty, qnan_value, plus_infty, qnan_value), - TEST_c_c (cacosh, 0, qnan_value, qnan_value, qnan_value), - TEST_c_c (cacosh, minus_zero, qnan_value, qnan_value, qnan_value), + /* The sign of the imaginary part of the result is unspecified + (see + ), + but the libm-test infrastructure does not support describing + that. */ + TEST_c_c (cacosh, 0, qnan_value, qnan_value, lit_pi_2_d), + TEST_c_c (cacosh, minus_zero, qnan_value, qnan_value, lit_pi_2_d), TEST_c_c (cacosh, qnan_value, plus_infty, plus_infty, qnan_value), TEST_c_c (cacosh, qnan_value, minus_infty, plus_infty, qnan_value), diff --git a/math/s_cacosh_template.c b/math/s_cacosh_template.c index 14f0b2a..0014fd4 100644 --- a/math/s_cacosh_template.c +++ b/math/s_cacosh_template.c @@ -57,7 +57,10 @@ M_DECL_FUNC (__cacosh) (CFLOAT x) else { __real__ res = M_NAN; - __imag__ res = M_NAN; + if (rcls == FP_ZERO) + __imag__ res = M_MLIT (M_PI_2); + else + __imag__ res = M_NAN; } } else if (rcls == FP_ZERO && icls == FP_ZERO) -- 2.7.4