sortix-mirror/libm/arch/i387/s_modf.S
Jonas 'Sortie' Termansen 5980be9b3c Add Sortix Math Library.
This work is based in part on code from NetBSD libm, libc and kernel.

The library is partly public domain and partly BSD-style licensed.
2013-12-17 14:30:39 +01:00

107 lines
3 KiB
ArmAsm

/* $NetBSD: s_modf.S,v 1.1 2006/03/22 20:45:58 drochner Exp $ */
/*-
* Copyright (c) 1990 The Regents of the University of California.
* All rights reserved.
*
* This code is derived from software contributed to Berkeley by
* Sean Eric Fagan.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* from: @(#)modf.s 5.5 (Berkeley) 3/18/91
*/
#include <machine/asm.h>
#if defined(LIBC_SCCS)
RCSID("$NetBSD: s_modf.S,v 1.1 2006/03/22 20:45:58 drochner Exp $")
#endif
/*
* modf(value, iptr): return fractional part of value, and stores the
* integral part into iptr (a pointer to double).
*
* Written by Sean Eric Fagan (sef@kithrup.COM)
* Sun Mar 11 20:27:30 PST 1990
*/
/* With CHOP mode on, frndint behaves as TRUNC does. Useful. */
ENTRY(modf)
#ifdef __x86_64__
pushq %rbp
movq %rsp,%rbp
subq $24,%rsp
/* Set chop mode. */
fnstcw -12(%rbp)
movw -12(%rbp),%dx
orw $3072,%dx
movw %dx,-16(%rbp)
fldcw -16(%rbp)
/* Get integral part. */
movsd %xmm0,-24(%rbp)
fldl -24(%rbp)
frndint
fstpl -8(%rbp)
/* Restore control word. */
fldcw -12(%rbp)
/* Store integral part. */
movsd -8(%rbp),%xmm0
movsd %xmm0,(%rdi)
/* Get fractional part and return it. */
fldl -24(%rbp)
fsubl -8(%rbp)
fstpl -24(%rbp)
movsd -24(%rbp),%xmm0
#else
pushl %ebp
movl %esp,%ebp
subl $16,%esp
fnstcw -12(%ebp)
movw -12(%ebp),%dx
orw $3072,%dx
movw %dx,-16(%ebp)
fldcw -16(%ebp)
fldl 8(%ebp)
frndint
fstpl -8(%ebp)
fldcw -12(%ebp)
movl 16(%ebp),%eax
movl -8(%ebp),%edx
movl -4(%ebp),%ecx
movl %edx,(%eax)
movl %ecx,4(%eax)
fldl 8(%ebp)
fsubl -8(%ebp)
jmp L1
L1:
#endif
leave
ret