xref: /titanic_50/usr/src/lib/libm/i386/src/log.s (revision ddc0e0b53c661f6e439e3b7072b3ef353eadb4af)
1*25c28e83SPiotr Jasiukajtis/*
2*25c28e83SPiotr Jasiukajtis * CDDL HEADER START
3*25c28e83SPiotr Jasiukajtis *
4*25c28e83SPiotr Jasiukajtis * The contents of this file are subject to the terms of the
5*25c28e83SPiotr Jasiukajtis * Common Development and Distribution License (the "License").
6*25c28e83SPiotr Jasiukajtis * You may not use this file except in compliance with the License.
7*25c28e83SPiotr Jasiukajtis *
8*25c28e83SPiotr Jasiukajtis * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9*25c28e83SPiotr Jasiukajtis * or http://www.opensolaris.org/os/licensing.
10*25c28e83SPiotr Jasiukajtis * See the License for the specific language governing permissions
11*25c28e83SPiotr Jasiukajtis * and limitations under the License.
12*25c28e83SPiotr Jasiukajtis *
13*25c28e83SPiotr Jasiukajtis * When distributing Covered Code, include this CDDL HEADER in each
14*25c28e83SPiotr Jasiukajtis * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15*25c28e83SPiotr Jasiukajtis * If applicable, add the following below this CDDL HEADER, with the
16*25c28e83SPiotr Jasiukajtis * fields enclosed by brackets "[]" replaced with your own identifying
17*25c28e83SPiotr Jasiukajtis * information: Portions Copyright [yyyy] [name of copyright owner]
18*25c28e83SPiotr Jasiukajtis *
19*25c28e83SPiotr Jasiukajtis * CDDL HEADER END
20*25c28e83SPiotr Jasiukajtis */
21*25c28e83SPiotr Jasiukajtis/*
22*25c28e83SPiotr Jasiukajtis * Copyright 2011 Nexenta Systems, Inc.  All rights reserved.
23*25c28e83SPiotr Jasiukajtis */
24*25c28e83SPiotr Jasiukajtis/*
25*25c28e83SPiotr Jasiukajtis * Copyright 2006 Sun Microsystems, Inc.  All rights reserved.
26*25c28e83SPiotr Jasiukajtis * Use is subject to license terms.
27*25c28e83SPiotr Jasiukajtis */
28*25c28e83SPiotr Jasiukajtis
29*25c28e83SPiotr Jasiukajtis	.file "log.s"
30*25c28e83SPiotr Jasiukajtis
31*25c28e83SPiotr Jasiukajtis#include "libm.h"
32*25c28e83SPiotr JasiukajtisLIBM_ANSI_PRAGMA_WEAK(log,function)
33*25c28e83SPiotr Jasiukajtis#include "libm_protos.h"
34*25c28e83SPiotr Jasiukajtis
35*25c28e83SPiotr Jasiukajtis	ENTRY(log)
36*25c28e83SPiotr Jasiukajtis	fldln2				/ loge(2)
37*25c28e83SPiotr Jasiukajtis	movl	8(%esp),%eax		/ eax <-- hi_32(x)
38*25c28e83SPiotr Jasiukajtis	testl	$0x80000000,%eax
39*25c28e83SPiotr Jasiukajtis	jnz	.maybe_0_or_less
40*25c28e83SPiotr Jasiukajtis	testl	$0x7fffffff,%eax
41*25c28e83SPiotr Jasiukajtis	jz	.maybe_0
42*25c28e83SPiotr Jasiukajtis	fldl	4(%esp)			/ arg, loge(2)
43*25c28e83SPiotr Jasiukajtis	fyl2x				/ loge(2)*log2(arg); ln(arg)
44*25c28e83SPiotr Jasiukajtis	ret
45*25c28e83SPiotr Jasiukajtis
46*25c28e83SPiotr Jasiukajtis.maybe_0:
47*25c28e83SPiotr Jasiukajtis	movl	4(%esp),%ecx		/ ecx <-- lo_32(x)
48*25c28e83SPiotr Jasiukajtis	cmpl	$0,%ecx
49*25c28e83SPiotr Jasiukajtis	je	.zero			/ no branch if x is +denormal
50*25c28e83SPiotr Jasiukajtis.neg_nan_reentry:
51*25c28e83SPiotr Jasiukajtis	fldl	4(%esp)			/ arg, loge(2)
52*25c28e83SPiotr Jasiukajtis	fyl2x				/ loge(2)*log2(arg); ln(arg)
53*25c28e83SPiotr Jasiukajtis	ret
54*25c28e83SPiotr Jasiukajtis
55*25c28e83SPiotr Jasiukajtis.zero_or_less:
56*25c28e83SPiotr Jasiukajtis	/ x =< 0
57*25c28e83SPiotr Jasiukajtis	testl	$0x7fffffff,%eax
58*25c28e83SPiotr Jasiukajtis	jnz	.less_than_0
59*25c28e83SPiotr Jasiukajtis	movl	4(%esp),%ecx		/ ecx <-- lo_32(x)
60*25c28e83SPiotr Jasiukajtis	cmpl	$0,%ecx
61*25c28e83SPiotr Jasiukajtis	jne	.less_than_0		/ branch if x is -denormal
62*25c28e83SPiotr Jasiukajtis.zero:
63*25c28e83SPiotr Jasiukajtis	/ x = +/-0
64*25c28e83SPiotr Jasiukajtis	pushl	%ebp
65*25c28e83SPiotr Jasiukajtis	movl	%esp,%ebp
66*25c28e83SPiotr Jasiukajtis	PIC_SETUP(1)
67*25c28e83SPiotr Jasiukajtis	pushl	$16
68*25c28e83SPiotr Jasiukajtis	jmp	.merge
69*25c28e83SPiotr Jasiukajtis
70*25c28e83SPiotr Jasiukajtis.maybe_0_or_less:
71*25c28e83SPiotr Jasiukajtis	cmpl	$0xfff00000,%eax	/ -INF below hi_32(x)?
72*25c28e83SPiotr Jasiukajtis	ja	.neg_nan_reentry
73*25c28e83SPiotr Jasiukajtis	jb	.zero_or_less
74*25c28e83SPiotr Jasiukajtis	movl	4(%esp),%ecx		/ ecx <-- lo_32(x)
75*25c28e83SPiotr Jasiukajtis	cmpl	$0,%ecx			/ is x NaN or -INF?
76*25c28e83SPiotr Jasiukajtis	jne	.neg_nan_reentry	/ branch if x is NaN with signbit = 1
77*25c28e83SPiotr Jasiukajtis	/ x = -INF
78*25c28e83SPiotr Jasiukajtis.less_than_0:
79*25c28e83SPiotr Jasiukajtis	pushl	%ebp
80*25c28e83SPiotr Jasiukajtis	movl	%esp,%ebp
81*25c28e83SPiotr Jasiukajtis	PIC_SETUP(2)
82*25c28e83SPiotr Jasiukajtis	pushl	$17
83*25c28e83SPiotr Jasiukajtis.merge:
84*25c28e83SPiotr Jasiukajtis	fstp	%st(0)			/ stack empty
85*25c28e83SPiotr Jasiukajtis	pushl	12(%ebp)
86*25c28e83SPiotr Jasiukajtis	pushl	8(%ebp)
87*25c28e83SPiotr Jasiukajtis	pushl	12(%ebp)
88*25c28e83SPiotr Jasiukajtis	pushl	8(%ebp)
89*25c28e83SPiotr Jasiukajtis	call	PIC_F(_SVID_libm_err)
90*25c28e83SPiotr Jasiukajtis	addl	$20,%esp
91*25c28e83SPiotr Jasiukajtis	PIC_WRAPUP
92*25c28e83SPiotr Jasiukajtis	leave
93*25c28e83SPiotr Jasiukajtis	ret
94*25c28e83SPiotr Jasiukajtis	.align	4
95*25c28e83SPiotr Jasiukajtis	SET_SIZE(log)
96