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Fix wordsize-64 cosh regression (bug 14273)
- From: "Joseph S. Myers" <joseph at codesourcery dot com>
- To: libc-alpha at sourceware dot org
- Date: Thu, 21 Jun 2012 16:27:49 +0000 (UTC)
- Subject: Fix wordsize-64 cosh regression (bug 14273)
This patch fixes bug 14273, spurious cosh overflows that are a
regression in 2.15 and 2.16 introduced by the dbl-64/wordsize-64
version of cosh.
Tested x86_64 and i386; no ulps updates needed, but it's certainly
possible that some other architecture will need an ulps update, so do
we wish to defer the testcase until after 2.16 branches and apply only
the code change to master before then (and apply only the code change
to 2.15 branch)?
(The input used in the tests is the result of rounding the input given
in the bug report to 53-bit precision.)
2012-06-21 Joseph Myers <joseph@codesourcery.com>
[BZ #14273]
* sysdeps/ieee754/dbl-64/wordsize-64/e_cosh.c: Clear sign bit of
64-bit integer value before comparing against overflow value.
* math/libm-test.inc (cosh_test): Add more tests.
diff --git a/math/libm-test.inc b/math/libm-test.inc
index 8e4d02e..48b05a6 100644
--- a/math/libm-test.inc
+++ b/math/libm-test.inc
@@ -2759,6 +2759,11 @@ cosh_test (void)
TEST_f_f (cosh, 0.75L, 1.29468328467684468784170818539018176L);
+#ifndef TEST_FLOAT
+ TEST_f_f (cosh, 709.8893558127259666434838436543941497802734375L, 9.9999998999995070652573675944761818416035e+307L);
+ TEST_f_f (cosh, -709.8893558127259666434838436543941497802734375L, 9.9999998999995070652573675944761818416035e+307L);
+#endif
+
END (cosh);
}
diff --git a/sysdeps/ieee754/dbl-64/wordsize-64/e_cosh.c b/sysdeps/ieee754/dbl-64/wordsize-64/e_cosh.c
index b8ab748..8459352 100644
--- a/sysdeps/ieee754/dbl-64/wordsize-64/e_cosh.c
+++ b/sysdeps/ieee754/dbl-64/wordsize-64/e_cosh.c
@@ -67,6 +67,7 @@ __ieee754_cosh (double x)
/* |x| in [log(maxdouble), overflowthresold] */
int64_t fix;
EXTRACT_WORDS64(fix, x);
+ fix &= UINT64_C(0x7fffffffffffffff);
if (fix <= UINT64_C(0x408633ce8fb9f87d)) {
w = __ieee754_exp(half*fabs(x));
t = half*w;
--
Joseph S. Myers
joseph@codesourcery.com