summaryrefslogtreecommitdiffstats
path: root/libm/amd64/s_remquof.S
blob: 02b604fa43e0f153906e46c04a15a2c87c585585 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
/*-
 * Copyright (c) 2005 David Schultz <das@FreeBSD.ORG>
 * All rights reserved.
 *
 * 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.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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.
 */

/*
 * Based on public-domain remainder routine by J.T. Conklin <jtc@NetBSD.org>.
 */

#include <machine/asm.h>
__FBSDID("$FreeBSD: src/lib/msun/amd64/s_remquof.S,v 1.1 2005/03/25 04:40:44 das Exp $"); 
	
ENTRY(remquof)
	movss	%xmm0,-4(%rsp)
	movss	%xmm1,-8(%rsp)
	flds	-8(%rsp)
	flds	-4(%rsp)
1:	fprem1
	fstsw	%ax
	btw	$10,%ax
	jc	1b
	fstp	%st(1)
/* Extract the three low-order bits of the quotient from C0,C3,C1. */
	shrl	$6,%eax
	movl	%eax,%ecx
	andl	$0x108,%eax
	rorl	$7,%eax
	orl	%eax,%ecx
	roll	$4,%eax
	orl	%ecx,%eax
	andl	$7,%eax
/* Negate the quotient bits if x*y<0.  Avoid using an unpredictable branch. */
	movl	-8(%rsp),%ecx
	xorl	-4(%rsp),%ecx
	sarl	$16,%ecx
	sarl	$16,%ecx
	xorl	%ecx,%eax
	andl	$1,%ecx
	addl	%ecx,%eax
/* Store the quotient and return. */
	movl	%eax,(%rdi)
	fstps	-4(%rsp)
	movss	-4(%rsp),%xmm0
	ret