diff options
| author | Joseph Myers <joseph@codesourcery.com> | 2016-06-23 22:17:41 +0000 |
|---|---|---|
| committer | Joseph Myers <joseph@codesourcery.com> | 2016-06-23 22:17:41 +0000 |
| commit | 40244be3729149ff440caf18e445ec17b0d0b511 (patch) | |
| tree | 17752b5c0173889687263d735f6f259909e31c5a /sysdeps/x86_64 | |
| parent | 7ed84b89f344c54dbf8665cb1cd29044bec62d18 (diff) | |
| download | glibc-40244be3729149ff440caf18e445ec17b0d0b511.tar.gz glibc-40244be3729149ff440caf18e445ec17b0d0b511.tar.xz glibc-40244be3729149ff440caf18e445ec17b0d0b511.zip | |
Fix i386/x86_64 scalbl with sNaN input (bug 20296).
The x86_64 and i386 versions of scalbl return sNaN for some cases of sNaN input and are missing "invalid" exceptions for other cases. This results from overly complicated code that either returns a NaN input, or discards both inputs when one is NaN and loads a NaN from memory. This patch fixes this by simplifying the code to add the arguments when either one is NaN. Tested for x86_64 and x86. [BZ #20296] * sysdeps/i386/fpu/e_scalbl.S (__ieee754_scalbl): Add arguments when either argument is a NaN. * sysdeps/x86_64/fpu/e_scalbl.S (__ieee754_scalbl): Likewise. * math/libm-test.inc (scalb_test_data): Add sNaN tests.
Diffstat (limited to 'sysdeps/x86_64')
| -rw-r--r-- | sysdeps/x86_64/fpu/e_scalbl.S | 13 |
1 files changed, 3 insertions, 10 deletions
diff --git a/sysdeps/x86_64/fpu/e_scalbl.S b/sysdeps/x86_64/fpu/e_scalbl.S index 331bee580c..2982dc3b9e 100644 --- a/sysdeps/x86_64/fpu/e_scalbl.S +++ b/sysdeps/x86_64/fpu/e_scalbl.S @@ -44,7 +44,7 @@ ENTRY(__ieee754_scalbl) fnstsw andl $0x4500, %eax cmpl $0x0100, %eax - je 3f + je 2f fld %st(1) frndint fcomip %st(2), %st @@ -75,15 +75,8 @@ ENTRY(__ieee754_scalbl) #endif ret - /* The result is NaN, but we must not raise an exception. - So use a variable. */ -2: fstp %st - fstp %st - fldl MO(nan) - ret - - /* The first parameter is a NaN. Return it. */ -3: fstp %st(1) + /* The result is NaN; raise an exception for sNaN arguments. */ +2: faddp ret /* Return NaN and raise the invalid exception. */ |