/*
 * 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 "log.s"

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

        ENTRY(log)
        fldln2                          / loge(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, loge(2)
        fyl2x                           / loge(2)*log2(arg); ln(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, loge(2)
        fyl2x                           / loge(2)*log2(arg); ln(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   $16
        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   $17
.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(log)