1/* $NetBSD: s_modf.S,v 1.1 2006/03/22 20:45:58 drochner Exp $ */ 2 3/*- 4 * Copyright (c) 1990 The Regents of the University of California. 5 * All rights reserved. 6 * 7 * This code is derived from software contributed to Berkeley by 8 * Sean Eric Fagan. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 3. Neither the name of the University nor the names of its contributors 19 * may be used to endorse or promote products derived from this software 20 * without specific prior written permission. 21 * 22 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 25 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 32 * SUCH DAMAGE. 33 * 34 * from: @(#)modf.s 5.5 (Berkeley) 3/18/91 35 */ 36 37#include <machine/asm.h> 38#if defined(LIBC_SCCS) 39 RCSID("$NetBSD: s_modf.S,v 1.1 2006/03/22 20:45:58 drochner Exp $") 40#endif 41 42/* 43 * modf(value, iptr): return fractional part of value, and stores the 44 * integral part into iptr (a pointer to double). 45 * 46 * Written by Sean Eric Fagan (sef@kithrup.COM) 47 * Sun Mar 11 20:27:30 PST 1990 48 */ 49 50/* With CHOP mode on, frndint behaves as TRUNC does. Useful. */ 51ENTRY(modf) 52#ifdef __x86_64__ 53 pushq %rbp 54 movq %rsp,%rbp 55 subq $24,%rsp 56 57 /* Set chop mode. */ 58 fnstcw -12(%rbp) 59 movw -12(%rbp),%dx 60 orw $3072,%dx 61 movw %dx,-16(%rbp) 62 fldcw -16(%rbp) 63 64 /* Get integral part. */ 65 movsd %xmm0,-24(%rbp) 66 fldl -24(%rbp) 67 frndint 68 fstpl -8(%rbp) 69 70 /* Restore control word. */ 71 fldcw -12(%rbp) 72 73 /* Store integral part. */ 74 movsd -8(%rbp),%xmm0 75 movsd %xmm0,(%rdi) 76 77 /* Get fractional part and return it. */ 78 fldl -24(%rbp) 79 fsubl -8(%rbp) 80 fstpl -24(%rbp) 81 movsd -24(%rbp),%xmm0 82#else 83 pushl %ebp 84 movl %esp,%ebp 85 subl $16,%esp 86 fnstcw -12(%ebp) 87 movw -12(%ebp),%dx 88 orw $3072,%dx 89 movw %dx,-16(%ebp) 90 fldcw -16(%ebp) 91 fldl 8(%ebp) 92 frndint 93 fstpl -8(%ebp) 94 fldcw -12(%ebp) 95 movl 16(%ebp),%eax 96 movl -8(%ebp),%edx 97 movl -4(%ebp),%ecx 98 movl %edx,(%eax) 99 movl %ecx,4(%eax) 100 fldl 8(%ebp) 101 fsubl -8(%ebp) 102 jmp L1 103L1: 104#endif 105 leave 106 ret 107