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authorJoseph Myers <joseph@codesourcery.com>2017-12-06 21:35:20 +0000
committerJoseph Myers <joseph@codesourcery.com>2017-12-06 21:35:20 +0000
commit5244527da1bfa751492e146d3e6ae128c59bfcc4 (patch)
tree28d4610ca18dc12b2ae6c7d7877e23ac26894942
parentd73fac82bedc124f00a39eba703e5a9c53e8028d (diff)
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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.
-rw-r--r--ChangeLog8
-rw-r--r--math/libm-test-cacosh.inc9
-rw-r--r--math/s_cacosh_template.c5
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 <joseph@codesourcery.com>
+
+ [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 <adhemerval.zanella@linaro.org>
* 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
+ <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)