diff options
| author | Joseph Myers <joseph@codesourcery.com> | 2015-09-30 21:44:42 +0000 |
|---|---|---|
| committer | Joseph Myers <joseph@codesourcery.com> | 2015-09-30 21:44:42 +0000 |
| commit | 8c6c9236361fbc077769673c259828216403bc33 (patch) | |
| tree | 04b02cf33c6654bc380d2c2ef986c41c4166d2ee /sysdeps/i386/fpu/e_acosh.S | |
| parent | 93e448cbed1095c88133f2a304b1bbba72e480af (diff) | |
Fix i386 acosh (-qNaN) spurious "invalid" exception.
The i386 versions of acoshf and acosh raise a spurious "invalid"
exception for an argument that is a quiet NaN with the sign bit set.
The integer arithmetic to detect arguments < 1 also detects -NaN, and
then the computation 0 / 0 in that case raises the exception. This
patch fixes this by using (x - x) / (x - x) as the computation in that
case instead, which will always raise the exception for non-NaN
arguments reaching that code, but not for quiet NaN arguments.
Tested for x86_64 and x86.
[BZ #19032]
* sysdeps/i386/fpu/e_acosh.S (__ieee754_acosh): For arguments < 1,
compute result as (x - x) / (x - x) not as 0 / 0.
* sysdeps/i386/fpu/e_acoshf.S (__ieee754_acoshf): Likewise.
* math/libm-test.inc (acosh_test_data): Add another test of acosh.
Diffstat (limited to 'sysdeps/i386/fpu/e_acosh.S')
| -rw-r--r-- | sysdeps/i386/fpu/e_acosh.S | 5 |
1 files changed, 3 insertions, 2 deletions
diff --git a/sysdeps/i386/fpu/e_acosh.S b/sysdeps/i386/fpu/e_acosh.S index c5cd4474ec..263c01a4ed 100644 --- a/sysdeps/i386/fpu/e_acosh.S +++ b/sysdeps/i386/fpu/e_acosh.S @@ -91,9 +91,10 @@ ENTRY(__ieee754_acosh) fyl2x // log(2*x+1/(x+sqrt(x^2-1))) ret - // x < 1 => NaN + // x < 1 (or -NaN) => NaN .align ALIGNARG(4) -5: fldz +5: fldl 4(%esp) + fsub %st fdiv %st, %st(0) ret END(__ieee754_acosh) |