/*
 * 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   "nexttowardl.s"

#include "libm.h"
LIBM_ANSI_PRAGMA_WEAK(nexttowardl,function)

        .section .rodata
        .align  4
.LFmaxl:        .long   0xffffffff,0xffffffff,0x00007ffe
.LFminl:        .long   0x1,0x0,0x0


        ENTRY(nexttowardl)
        pushl   %ebp
        movl    %esp,%ebp
        fldt    20(%ebp)        / y
        subl    $12,%esp
        fldt    8(%ebp)         / load x
        fucom                   / x : y
        fstsw   %ax
        sahf
        jp      .LNaN
        je      .Lequal
        fstp    %st(1)          / x
        ja      .Lbigger
        / x < y
        ftst
        movl    $1,-12(%ebp)    /// -12(%ebp) contains Fminl
        movl    $0,-8(%ebp)
        movl    $0,%ecx                 /// final needs this
        movl    %ecx,-4(%ebp)
        fnstsw  %ax
        sahf
        je      .Lfinal
        ja      .Laddulp
        jb      .Lsubulp
.Lbigger:
        / x > y
        ftst
        movl    $1,-12(%ebp)    /// -12(%ebp) contains -Fminl
        movl    $0,-8(%ebp)
        movl    $0x00008000,%ecx        /// final needs this
        movl    %ecx,-4(%ebp)
        fnstsw  %ax
        sahf
        je      .Lfinal
        jb      .Laddulp
.Lsubulp:
        movl    12(%ebp),%edx   / high word of significand of x
        movl    16(%ebp),%ecx   / x's exponent
        andl    $0x0000ffff,%ecx
        movl    %edx,%eax
        not     %eax
        andl    $0x80000000,%eax        / look at explicit leading bit
        orl     %ecx,%eax
        andl    $0x80007fff,%eax
        jnz     .Lnot_pseudonormal      / zero value implies pseudonormal
        addl    $1,%ecx         / if pseudonormal, turn into equivalent normal
.Lnot_pseudonormal:
        movl    8(%ebp),%eax    / low x
        subl    $1,%eax         / low x - ulp
        movl    %eax,-12(%ebp)
        cmpl    $0xffffffff,%eax        / this means low x was 0
        jz      .Lborrow
        movl    %edx,-8(%ebp)
        movl    %ecx,-4(%ebp)
        jmp     .Lfinal
.Lborrow:
        cmpl    $0x80000000,%edx        / look at high x
        je      .Lsecond_borrow
        subl    $1,%edx
        movl    %edx,-8(%ebp)
        movl    %ecx,-4(%ebp)
        jmp     .Lfinal
.Lsecond_borrow:
        movl    %ecx,%eax
        andl    $0x7fff,%eax    / look at exp x without sign bit
        cmpl    $1,%eax
        jbe     .Lsubnormal_result      / exp > 1 ==> result will be normal
        movl    $0xffffffff,-8(%ebp)
        subl    $1,%ecx
        movl    %ecx,-4(%ebp)
        jmp     .Lfinal
.Lsubnormal_result:
        movl    $0x7fffffff,-8(%ebp)
        movl    %ecx,%eax
        andl    $0x8000,%eax    / look at sign bit
        jz      .Lpositive
        movl    $0x8000,%ecx
        movl    %ecx,-4(%ebp)
        jmp     .Lfinal
.Lpositive:
        movl    $0,%ecx
        movl    %ecx,-4(%ebp)
        jmp     .Lfinal
.Laddulp:
        movl    12(%ebp),%edx   / high x
        movl    16(%ebp),%ecx   / x's exponent
        andl    $0x0000ffff,%ecx
        movl    %edx,%eax
        not     %eax
        andl    $0x80000000,%eax        / look at explicit leading bit
        orl     %ecx,%eax
        andl    $0x80007fff,%eax
        jnz     .Lnot_pseudonormal_2    / zero value implies pseudonormal
        addl    $1,%ecx
.Lnot_pseudonormal_2:
        movl    8(%ebp),%eax    / low x
        addl    $1,%eax         / low x + ulp
        movl    %eax,-12(%ebp)
        jz      .Lcarry         / jump if the content of %eax is 0
        movl    %edx,-8(%ebp)
        movl    %ecx,-4(%ebp)
        jmp .Lfinal
.Lcarry:
        movl    %edx,%eax
        andl    $0x7fffffff,%eax
        cmpl    $0x7fffffff,%eax        / look at high x
        je      .Lsecond_carry
        addl    $1,%edx
        movl    %edx,-8(%ebp)
        movl    %ecx,-4(%ebp)
        jmp     .Lfinal
.Lsecond_carry:
        movl    $0x80000000,-8(%ebp)
        addl    $1,%ecx
        movl    %ecx,-4(%ebp)
.Lfinal:
        fstp    %st(0)
        fldt    -12(%ebp)
        andl    $0x00007fff,%ecx
        jz      .Lunderflow
        cmpw    $0x7fff,%cx
        je      .Loverflow
        jmp     .Lreturn
.Loverflow:
        PIC_SETUP(1)
        fldt    PIC_L(.LFmaxl)
        PIC_WRAPUP
        fmulp   %st,%st(0)      / create overflow signal
        jmp     .Lreturn
.Lunderflow:
        PIC_SETUP(2)
        fldt    PIC_L(.LFminl)
        PIC_WRAPUP
        fmulp   %st,%st(0)      / create underflow signal
        jmp     .Lreturn
.Lequal:
        fstp    %st(0)          / C99 says to return y when x == y
        jmp     .Lreturn
.LNaN:
        faddp   %st,%st(1)      / x+y,x
.Lreturn:
        fwait
        leave
        ret
        .align  4
        SET_SIZE(nexttowardl)