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Fix csin, csinh overflow in directed rounding modes (bug 18593).

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csin and csinh can produce bad results when overflowing in directed
rounding modes, because a multiplication that can overflow is followed
by a possible negation.  This patch fixes this by negating one of the
arguments of the multiplication before the multiplication instead of
negating the result.

The new tests for this issue are added to auto-libm-test-in, starting
use of that file for csin and csinh.  The issue was found in the
course of moving existing tests for csin and csinh (existing tests, by
being enabled in more cases than previously, showed the issue for
float and double but not for long double); that move will now be done
separately.

Tested for x86_64 and x86 and ulps updated accordingly.

	[BZ #18593]
	* math/s_csin.c (__csin): Negate before rather than after possibly
	overflowing multiplication.
	* math/s_csinf.c (__csinf): Likewise.
	* math/s_csinh.c (__csinh): Likewise.
	* math/s_csinhf.c (__csinhf): Likewise.
	* math/s_csinhl.c (__csinhl): Likewise.
	* math/s_csinl.c (__csinl): Likewise.
	* math/auto-libm-test-in: Add some tests of csin and csinh.
	* math/auto-libm-test-out: Regenerated.
	* math/libm-test.inc (csin_test_data): Use AUTO_TESTS_c_c.
	(csinh_test_data): Likewise.
	* sysdeps/x86_64/fpu/libm-test-ulps: Update.
This commit is contained in:
Joseph Myers
2015-06-24 16:20:48 +00:00
parent 8475ab1684
commit ac831b362a
12 changed files with 251 additions and 23 deletions
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4
math/libm-test.inc
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@ -6466,6 +6466,8 @@ static const struct test_c_c_data csin_test_data[] =
TEST_c_c (csin, 0x1p-16434L, 22730, 1.217853148905605987081057582351152052687e4924L, plus_oflow, OVERFLOW_EXCEPTION),
#endif
AUTO_TESTS_c_c (csin),
TEST_c_c (csin, min_subnorm_value, min_value, min_subnorm_value, min_value, UNDERFLOW_EXCEPTION),
TEST_c_c (csin, min_value, min_subnorm_value, min_value, min_subnorm_value, UNDERFLOW_EXCEPTION),
};
@ -6563,6 +6565,8 @@ static const struct test_c_c_data csinh_test_data[] =
TEST_c_c (csinh, 22730, 0x1p-16434L, plus_oflow, 1.217853148905605987081057582351152052687e4924L, OVERFLOW_EXCEPTION),
#endif
AUTO_TESTS_c_c (csinh),
TEST_c_c (csinh, min_subnorm_value, min_value, min_subnorm_value, min_value, UNDERFLOW_EXCEPTION),
TEST_c_c (csinh, min_value, min_subnorm_value, min_value, min_subnorm_value, UNDERFLOW_EXCEPTION),
};