i386/src/log10.s

	log10.s revision ddc0e0b53c661f6e439e3b7072b3ef353eadb4af
/*
 * 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 "log10.s"

#include "libm.h"
LIBM_ANSI_PRAGMA_WEAK(log10,function)
#include "libm_protos.h"

    ENTRY(log10)
    fldlg2              / log10(2)
    movl    8(%esp),%eax        / eax <-- hi_32(x)
    testl   $0x80000000,%eax
    jnz .maybe_0_or_less
    testl   $0x7fffffff,%eax
    jz  .maybe_0
    fldl    4(%esp)         / arg, log10(2)
    fyl2x               / log10(2)*log2(arg); log10(arg)
    ret

.maybe_0:
    movl    4(%esp),%ecx        / ecx <-- lo_32(x)
    cmpl    $0,%ecx
    je  .zero           / no branch if x is +denormal
.neg_nan_reentry:
    fldl    4(%esp)         / arg, log10(2)
    fyl2x               / log10(2)*log2(arg); log10(arg)
    ret

.zero_or_less:
    / x =< 0
    testl   $0x7fffffff,%eax
    jnz .less_than_0
    movl    4(%esp),%ecx        / ecx <-- lo_32(x)
    cmpl    $0,%ecx
    jne .less_than_0        / branch if x is -denormal
.zero:
    / x = +/-0
    pushl   %ebp
    movl    %esp,%ebp
    PIC_SETUP(1)
    pushl   $18
    jmp .merge

.maybe_0_or_less:
    cmpl    $0xfff00000,%eax    / -INF below hi_32(x)?
    ja  .neg_nan_reentry
    jb  .zero_or_less
    movl    4(%esp),%ecx        / ecx <-- lo_32(x)
    cmpl    $0,%ecx         / is x NaN or -INF?
    jne .neg_nan_reentry    / branch if x is NaN with signbit = 1
    / x = -INF
.less_than_0:
    pushl   %ebp
    movl    %esp,%ebp
    PIC_SETUP(2)
    pushl   $19
.merge:
    fstp    %st(0)          / stack empty
    pushl   12(%ebp)
    pushl   8(%ebp)
    pushl   12(%ebp)
    pushl   8(%ebp)
    call    PIC_F(_SVID_libm_err)
    addl    $20,%esp
    PIC_WRAPUP
    leave
    ret
    .align  4
    SET_SIZE(log10)