nextafterf.s revision 25c28e83beb90e7c80452a7c818c5e6f73a07dc8
/*
* CDDL HEADER START
*
* The contents of this file are subject to the terms of the
* Common Development and Distribution License (the "License").
* You may not use this file except in compliance with the License.
*
* You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
* or http://www.opensolaris.org/os/licensing.
* See the License for the specific language governing permissions
* and limitations under the License.
*
* When distributing Covered Code, include this CDDL HEADER in each
* file and include the License file at usr/src/OPENSOLARIS.LICENSE.
* If applicable, add the following below this CDDL HEADER, with the
* fields enclosed by brackets "[]" replaced with your own identifying
* information: Portions Copyright [yyyy] [name of copyright owner]
*
* CDDL HEADER END
*/
/*
* Copyright 2011 Nexenta Systems, Inc. All rights reserved.
*/
/*
* Copyright 2006 Sun Microsystems, Inc. All rights reserved.
* Use is subject to license terms.
*/
.file "nextafterf.s"
#include "libm.h"
LIBM_ANSI_PRAGMA_WEAK(nextafterf,function)
#include "libm_synonyms.h"
.data
.align 4
Fmaxf: .long 0x7f7fffff
Fminf: .long 0x1
ftmpf: .long 0
ENTRY(nextafterf)
pushl %ebp
movl %esp,%ebp
movl $0,%eax /// upper half of %eax must be initialized
flds 12(%ebp) / y
subl $4,%esp
flds 8(%ebp) / x, y
fucom / x : y
fstsw %ax
sahf
jp .NaN
je .equal
fstp %st(1) / x
ja .bigger
/ x < y
ftst / x : 0
movl $0x1,-4(%ebp) / -4(%ebp) contains Fminf
fnstsw %ax
sahf
je .final
ja .addulp
jb .subulp
.bigger:
/ x > y
ftst / x : 0
movl $0x80000001,-4(%ebp) / -4(%ebp) contains -Fminf
fnstsw %ax
sahf
je .final
jb .addulp
.subulp:
movl 8(%ebp),%eax / x
subl $1,%eax / x - ulp
movl %eax,-4(%ebp)
jmp .final
.addulp:
movl 8(%ebp),%eax / x
addl $1,%eax / x + ulp
movl %eax,-4(%ebp)
.final:
fstp %st(0) / empty
flds -4(%ebp) / z
andl $0x7f800000,%eax
jz .underflow
cmpl $0x7f800000,%eax
je .overflow
jmp .return
.overflow:
PIC_SETUP(1)
flds PIC_L(Fmaxf) / Fmaxf, z
fmul %st(0),%st / overflow-to-Inf, z
fstps PIC_L(ftmpf) / z & create overflow signal
PIC_WRAPUP
jmp .return
.underflow:
PIC_SETUP(2)
flds PIC_L(Fminf) / Fminf, z
fmul %st(0),%st / underflow-to-0, z
fstps PIC_L(ftmpf) / z & create underflow signal
PIC_WRAPUP
jmp .return
.equal:
fstp %st(0) / C99 says to return y when x == y
jmp .return
.NaN:
faddp %st,%st(1) / x+y
.return:
fwait
leave
ret
.align 4
SET_SIZE(nextafterf)