diff options
Diffstat (limited to 'sysdeps/x86_64/fpu/s_ilogbl.S')
| -rw-r--r-- | sysdeps/x86_64/fpu/s_ilogbl.S | 35 |
1 files changed, 35 insertions, 0 deletions
diff --git a/sysdeps/x86_64/fpu/s_ilogbl.S b/sysdeps/x86_64/fpu/s_ilogbl.S new file mode 100644 index 0000000000..f59040c11e --- /dev/null +++ b/sysdeps/x86_64/fpu/s_ilogbl.S @@ -0,0 +1,35 @@ +/* + * Written by J.T. Conklin <jtc@netbsd.org>. + * Changes for long double by Ulrich Drepper <drepper@cygnus.com> + * Adapted for x86-64 by Andreas Jaeger <aj@suse.de>. + * Public domain. + */ + +#include <machine/asm.h> + +ENTRY(__ilogbl) + fldt 8(%rsp) +/* 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. */ + + fxtract + fstp %st + + fistpl -4(%rsp) + fwait + movl -4(%rsp),%eax + + ret + +1: fstp %st + movl $0x7fffffff, %eax + ret +END (__ilogbl) +weak_alias (__ilogbl, ilogbl) |