| /* |
| * Written by J.T. Conklin <jtc@netbsd.org>. |
| * Public domain. |
| */ |
| |
| #include <machine/asm.h> |
| |
| RCSID("$NetBSD: s_ilogbf.S,v 1.4 1995/10/22 20:32:43 pk Exp $") |
| |
| ENTRY(__ieee754_ilogbf) |
| flds 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_ilogbf) |
