diff options
| author | Joseph Myers <joseph@codesourcery.com> | 2014-06-10 12:07:15 +0000 |
|---|---|---|
| committer | Joseph Myers <joseph@codesourcery.com> | 2014-06-10 12:07:15 +0000 |
| commit | f8ba1b5654d876c8db4c9a020e6fa976d434f988 (patch) | |
| tree | f5e34ce57471cbb1c54ec4cd0492b665f94151bb /math | |
| parent | 2c3520d98d9773d9e092196c3c36150244eed1dd (diff) | |
Fix log2 (1) in round-downward mode (bug 17042).
As with other issues of this kind, bug 17042 is log2 (1) wrongly
returning -0 instead of +0 in round-downward mode because of
implementations effectively in terms of log1p (x - 1). This patch
fixes the issue in the same way used for log and log10.
Tested x86_64 and x86 and ulps updated accordingly. Also tested for
mips64 to confirm a fix was needed for ldbl-128 and to validate that
fix (also applied to ldbl-128ibm since that version of log2l is
essentially the same as the ldbl-128 one).
[BZ #17042]
* sysdeps/i386/fpu/e_log2.S (__ieee754_log2): Take absolete value
when x - 1 is zero.
* sysdeps/i386/fpu/e_log2f.S (__ieee754_log2f): Likewise.
* sysdeps/i386/fpu/e_log2l.S (__ieee754_log2l): Likewise.
* sysdeps/ieee754/ldbl-128/e_log2l.c (__ieee754_log2l): Return
0.0L for an argument of 1.0L.
* sysdeps/ieee754/ldbl-128ibm/e_log2l.c (__ieee754_log2l):
Likewise.
* sysdeps/x86_64/fpu/e_log2l.S (__ieee754_log2l): Take absolute
value when x - 1 is zero.
* math/libm-test.inc (log2_test): Use ALL_RM_TEST.
* sysdeps/i386/fpu/libm-test-ulps: Update.
* sysdeps/x86_64/fpu/libm-test-ulps: Likewise.
Diffstat (limited to 'math')
| -rw-r--r-- | math/libm-test.inc | 4 |
1 files changed, 1 insertions, 3 deletions
diff --git a/math/libm-test.inc b/math/libm-test.inc index 0d467a2195..fa8e2385dc 100644 --- a/math/libm-test.inc +++ b/math/libm-test.inc @@ -7840,9 +7840,7 @@ static const struct test_f_f_data log2_test_data[] = static void log2_test (void) { - START (log2, 0); - RUN_TEST_LOOP_f_f (log2, log2_test_data, ); - END; + ALL_RM_TEST (log2, 0, log2_test_data, RUN_TEST_LOOP_f_f, END); } |