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| author | Joseph Myers <joseph@codesourcery.com> | 2017-12-06 21:35:20 +0000 |
|---|---|---|
| committer | Joseph Myers <joseph@codesourcery.com> | 2017-12-06 21:35:20 +0000 |
| commit | 5244527da1bfa751492e146d3e6ae128c59bfcc4 (patch) | |
| tree | 28d4610ca18dc12b2ae6c7d7877e23ac26894942 /math | |
| parent | d73fac82bedc124f00a39eba703e5a9c53e8028d (diff) | |
| download | glibc-5244527da1bfa751492e146d3e6ae128c59bfcc4.zip glibc-5244527da1bfa751492e146d3e6ae128c59bfcc4.tar.gz glibc-5244527da1bfa751492e146d3e6ae128c59bfcc4.tar.bz2 | |
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.
Diffstat (limited to 'math')
| -rw-r--r-- | math/libm-test-cacosh.inc | 9 | ||||
| -rw-r--r-- | math/s_cacosh_template.c | 5 |
2 files changed, 11 insertions, 3 deletions
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 + <http://www.open-std.org/jtc1/sc22/wg14/www/docs/n2173.htm>), + 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) |