diff options
| author | Adhemerval Zanella <azanella@linux.vnet.ibm.com> | 2012-04-11 16:30:13 -0300 |
|---|---|---|
| committer | Andreas Jaeger <aj@suse.de> | 2012-04-17 22:12:53 +0200 |
| commit | 76da7265320010c7a273ed99f53938c0f32d5fad (patch) | |
| tree | f094871a5f38652d2d320a11423fee602a8746e6 /sysdeps/i386/fpu/e_ilogbl.S | |
| parent | 0396e69dbefb3630651d93e0a7526c4326a071bb (diff) | |
| download | glibc-76da7265320010c7a273ed99f53938c0f32d5fad.tar.gz | |
Fix ilogb exception and errno (bug 6794)
[BZ #6794]
Following Joseph comments about bug 6794, here is a proposed fix. It turned out
to be a large fix mainly because I had to move some file along to follow libm
files/names conventions.
Basically I have added wrappers (w_ilogb.c, w_ilogbf.c, w_ilogbl.c) that now calls
the symbol '__ieee754_ilogb'. The wrappers checks for '__ieee754_ilogb' output and
set the errno and raise exceptions as expected.
The '__ieee754_ilogb' is implemented in sysdeps. I have moved the 's_ilogb[f|l]' files
to e_ilogb[f|l] and renamed the '__ilogb[f|l]' to '__ieee754_ilogb[f|l]'.
I also found out a bug in i386 and x86-64 assembly coded ilogb implementation where
it raises a FE_DIVBYZERO when argument is '0.0'. I corrected this issue as well.
Finally I added the errno and FE_INVALID tests for 0.0, NaN and +-InF argument. Tested
on i386, x86-64, ppc32 and ppc64.
Diffstat (limited to 'sysdeps/i386/fpu/e_ilogbl.S')
| -rw-r--r-- | sysdeps/i386/fpu/e_ilogbl.S | 44 |
1 files changed, 44 insertions, 0 deletions
diff --git a/sysdeps/i386/fpu/e_ilogbl.S b/sysdeps/i386/fpu/e_ilogbl.S new file mode 100644 index 0000000000..6e2be9a300 --- /dev/null +++ b/sysdeps/i386/fpu/e_ilogbl.S @@ -0,0 +1,44 @@ +/* + * Written by J.T. Conklin <jtc@netbsd.org>. + * Changes for long double by Ulrich Drepper <drepper@cygnus.com> + * Public domain. + */ + +#include <machine/asm.h> + +RCSID("$NetBSD: $") + +ENTRY(__ieee754_ilogbl) + fldt 4(%esp) +/* I added the following ugly construct because ilogb(+-Inf) is + required to return INT_MAX in ISO C99. + -- jakub@redhat.com. */ + fxam /* Is NaN or +-Inf? */ + fstsw %ax + movb $0x45, %dh + andb %ah, %dh + cmpb $0x05, %dh + je 1f /* Is +-Inf, jump. */ + cmpb $0x40, %dh + je 2f /* Is +-0, jump. */ + + fxtract + pushl %eax + cfi_adjust_cfa_offset (4) + fstp %st + + fistpl (%esp) + fwait + popl %eax + cfi_adjust_cfa_offset (-4) + + ret + +1: fstp %st + movl $0x7fffffff, %eax + ret +2: fstp %st + movl $0x80000000, %eax /* FP_ILOGB0 */ + ret +END (__ieee754_ilogbl) +weak_alias (__ieee754_ilogbl, __ilogbl_finite) |