/* * Written by J.T. Conklin <jtc@netbsd.org>. * Public domain. */ #include <machine/asm.h> RCSID("$NetBSD: s_ilogb.S,v 1.5 1995/10/12 15:53:09 jtc Exp $") ENTRY(__ieee754_ilogb) fldl 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_ilogb)