/*
 * 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 "exp10l.s"

#include "libm.h"

        .data
        .align  4
lt2_hi: .long   0xfbd00000, 0x9a209a84, 0x00003ffd
lt2_lo: .long   0x653f4837, 0x8677076a, 0x0000bfc9

        ENTRY(exp10l)
        movl    12(%esp),%ecx           / cx <--sign&bexp(x)
        andl    $0x00007fff,%ecx        / ecx <-- zero_xtnd(bexp(x))
        cmpl    $0x00003ffd,%ecx        / Is |x| < log10(2)?
        jb      .shortcut               / If so, take a shortcut.
        je      .check_tail             / maybe |x| only slightly < log10(2)
        cmpl    $0x00007fff,%ecx        / bexp(|x|) = bexp(INF)?
        je      .not_finite             / if so, x is not finite
        cmpl    $0x0000400e,%ecx        / |x| < 32768 = 2^15?
        jb      .finite_non_special     / if so, proceed with argument reduction
        fldt    4(%esp)                 / x
        fld1                            / 1, x
        jmp     1f
.finite_non_special:                    / Here, log10(2) < |x| < 2^15
        fldt    4(%esp)                 / x
        fld     %st(0)                  / x, x
        fldl2t                          / log2(10), x, x
        fmulp                           / z := x*log2(10), x
        frndint                         / [z], x
        fst     %st(2)                  / [z], x, [z]
        PIC_SETUP(1)
        fldt    PIC_L(lt2_hi)           / lt2_hi, [z], x, [z]
        fmulp                           / [z]*lt2_hi, x, [z]
        fsubrp  %st,%st(1)              / x-[z]*lt2_hi, [z]
        fldt    PIC_L(lt2_lo)           / lt2_lo, x-[z]*lt2_hi, [z]
        PIC_WRAPUP
        fmul    %st(2),%st              / [z]*lt2_lo, x-[z]*lt2_hi, [z]
        fsubrp  %st,%st(1)              / r := x-[z]*log10(2), [z]
        fldl2t                          / log2(10), r, [z]
        fmulp                           / f := r*log2(10), [z]
        f2xm1                           / 2^f-1,[z]
        fld1                            / 1, 2^f-1, [z]
        faddp   %st,%st(1)              / 2^f, [z]
1:
        fscale                          / 10^x, [z]
        fstp    %st(1)
        ret

.check_tail:
        movl    8(%esp),%ecx            / ecx <-- hi_32(sgnfcnd(x))
        cmpl    $0x9a209a84,%ecx        / Is |x| < log10(2)?
        ja      .finite_non_special
        jb      .shortcut
        movl    4(%esp),%edx            / edx <-- lo_32(sgnfcnd(x))
        cmpl    $0xfbcff798,%edx        / Is |x| slightly > log10(2)?
        ja      .finite_non_special     / branch if |x| slightly > log10(2)
.shortcut:
        / Here, |x| < log10(2), so |z| = |x/log10(2)| < 1
        / whence z is in f2xm1's domain.
        fldt    4(%esp)                 / x
        fldl2t                          / log2(10), x
        fmulp                           / z := x*log2(10)
        f2xm1                           / 2^z-1
        fld1                            / 1, 2^z-1
        faddp   %st,%st(1)              / 10^x
        ret

.not_finite:
        movl    8(%esp),%ecx            / ecx <-- hi_32(sgnfcnd(x))
        cmpl    $0x80000000,%ecx        / hi_32(sgnfcnd(x)) = hi_32(sgnfcnd(INF))?
        jne     .NaN_or_pinf            / if not, x is NaN or unsupp.
        movl    4(%esp),%edx            / edx <-- lo_32(sgnfcnd(x))
        cmpl    $0,%edx                 / lo_32(sgnfcnd(x)) = 0?
        jne     .NaN_or_pinf            / if not, x is NaN
        movl    12(%esp),%eax           / ax <-- sign&bexp((x))
        andl    $0x00008000,%eax        / here, x is infinite, but +/-?
        jz      .NaN_or_pinf            / branch if x = +INF
        fldz                            / Here, x = -inf, so return 0
        ret

.NaN_or_pinf:
        / Here, x = NaN or +inf, so load x and return immediately.
        fldt    4(%esp)
        ret
        .align  4
        SET_SIZE(exp10l)