usr/src/sys/tahoe/math/Kfrexpf.s

/*-
 * Copyright (c) 1985 The Regents of the University of California.
 * All rights reserved.
 *
 * This code is derived from software contributed to Berkeley by
 * Computer Consoles Inc.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *      This product includes software developed by the University of
 *      California, Berkeley and its contributors.
 * 4. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 *      @(#)Kfrexpf.s   7.1 (Berkeley) 12/6/90
 */

#include "../tahoe/SYS.h"

        .text
ENTRY(Kfrexpf, 0)
        subl3   $60,fp,sp
        clrl    -60(fp)         # j=0;
        clrl    -56(fp)         # neg=0;
        tstl    4(fp)           # if(x<0){
        jgeq    1f
        lnd     4(fp)
        std     4(fp)           # x = -x;
        movl    $1,-56(fp)      # neg=1;}
1:
        cmpd2   4(fp),one       # if (x>1){
        jleq    1f
2:
        cmpd2   4(fp),one       # while(x>1){
        jleq    3f
        addl2   $1,-60(fp)      # j=j+1;
        pushl   16(fp)          # hfs
        ldd     two
        pushd
        ldd     4(fp)
        pushd
        callf   $24,_Kdivd
        ldd     r0
        std     4(fp)           # x= x/2;
        jbr     2b
1:
        cmpd2   4(fp),half      # if(x<0.5){
        jlss    2f
        jbr     3f
0:
        subl2   $1,-60(fp)      # j = j-1;
        pushl   16(fp)          # hfs
        ldd     4(fp)
        pushd
        ldd     two
        pushd
        callf   $24,_Kmuld
        ldd     r0
        std     4(fp)           # x = 2*x;
2:
        cmpd2   4(fp),half      # while (x<0.5){
        jlss    0b
3:
        movl    -60(fp),*12(fp) # *i=j;
        tstl    -56(fp)         # if (neg)
        jeql    1f
        lnd     4(fp)
        std     4(fp)
1:
        ldd     4(fp)
        cvdf
        stf     r0
        ret

        .data
        .align  2
one:    .long   0x40800000, 0x00000000 # .double 1
two:    .long   0x41000000, 0x00000000 # .double 2
half:   .long   0x40000000, 0x00000000 # .double .5