| 1 |
30 |
unneback |
//
|
| 2 |
|
|
// $Id: smovecr.S,v 1.2 2001-09-27 12:01:22 chris Exp $
|
| 3 |
|
|
//
|
| 4 |
|
|
// smovecr.sa 3.1 12/10/90
|
| 5 |
|
|
//
|
| 6 |
|
|
// The entry point sMOVECR returns the constant at the
|
| 7 |
|
|
// offset given in the instruction field.
|
| 8 |
|
|
//
|
| 9 |
|
|
// Input: An offset in the instruction word.
|
| 10 |
|
|
//
|
| 11 |
|
|
// Output: The constant rounded to the user's rounding
|
| 12 |
|
|
// mode unchecked for overflow.
|
| 13 |
|
|
//
|
| 14 |
|
|
// Modified: fp0.
|
| 15 |
|
|
//
|
| 16 |
|
|
//
|
| 17 |
|
|
// Copyright (C) Motorola, Inc. 1990
|
| 18 |
|
|
// All Rights Reserved
|
| 19 |
|
|
//
|
| 20 |
|
|
// THIS IS UNPUBLISHED PROPRIETARY SOURCE CODE OF MOTOROLA
|
| 21 |
|
|
// The copyright notice above does not evidence any
|
| 22 |
|
|
// actual or intended publication of such source code.
|
| 23 |
|
|
|
| 24 |
|
|
//SMOVECR idnt 2,1 | Motorola 040 Floating Point Software Package
|
| 25 |
|
|
|
| 26 |
|
|
|section 8
|
| 27 |
|
|
|
| 28 |
|
|
#include "fpsp.defs"
|
| 29 |
|
|
|
| 30 |
|
|
|xref nrm_set
|
| 31 |
|
|
|xref round
|
| 32 |
|
|
|xref PIRN
|
| 33 |
|
|
|xref PIRZRM
|
| 34 |
|
|
|xref PIRP
|
| 35 |
|
|
|xref SMALRN
|
| 36 |
|
|
|xref SMALRZRM
|
| 37 |
|
|
|xref SMALRP
|
| 38 |
|
|
|xref BIGRN
|
| 39 |
|
|
|xref BIGRZRM
|
| 40 |
|
|
|xref BIGRP
|
| 41 |
|
|
|
| 42 |
|
|
FZERO: .long 00000000
|
| 43 |
|
|
//
|
| 44 |
|
|
// FMOVECR
|
| 45 |
|
|
//
|
| 46 |
|
|
.global smovcr
|
| 47 |
|
|
smovcr:
|
| 48 |
|
|
bfextu CMDREG1B(%a6){#9:#7},%d0 //get offset
|
| 49 |
|
|
bfextu USER_FPCR(%a6){#26:#2},%d1 //get rmode
|
| 50 |
|
|
//
|
| 51 |
|
|
// check range of offset
|
| 52 |
|
|
//
|
| 53 |
|
|
tstb %d0 //if zero, offset is to pi
|
| 54 |
|
|
beqs PI_TBL //it is pi
|
| 55 |
|
|
cmpib #0x0a,%d0 //check range $01 - $0a
|
| 56 |
|
|
bles Z_VAL //if in this range, return zero
|
| 57 |
|
|
cmpib #0x0e,%d0 //check range $0b - $0e
|
| 58 |
|
|
bles SM_TBL //valid constants in this range
|
| 59 |
|
|
cmpib #0x2f,%d0 //check range $10 - $2f
|
| 60 |
|
|
bles Z_VAL //if in this range, return zero
|
| 61 |
|
|
cmpib #0x3f,%d0 //check range $30 - $3f
|
| 62 |
|
|
ble BG_TBL //valid constants in this range
|
| 63 |
|
|
Z_VAL:
|
| 64 |
|
|
fmoves FZERO,%fp0
|
| 65 |
|
|
rts
|
| 66 |
|
|
PI_TBL:
|
| 67 |
|
|
tstb %d1 //offset is zero, check for rmode
|
| 68 |
|
|
beqs PI_RN //if zero, rn mode
|
| 69 |
|
|
cmpib #0x3,%d1 //check for rp
|
| 70 |
|
|
beqs PI_RP //if 3, rp mode
|
| 71 |
|
|
PI_RZRM:
|
| 72 |
|
|
leal PIRZRM,%a0 //rmode is rz or rm, load PIRZRM in a0
|
| 73 |
|
|
bra set_finx
|
| 74 |
|
|
PI_RN:
|
| 75 |
|
|
leal PIRN,%a0 //rmode is rn, load PIRN in a0
|
| 76 |
|
|
bra set_finx
|
| 77 |
|
|
PI_RP:
|
| 78 |
|
|
leal PIRP,%a0 //rmode is rp, load PIRP in a0
|
| 79 |
|
|
bra set_finx
|
| 80 |
|
|
SM_TBL:
|
| 81 |
|
|
subil #0xb,%d0 //make offset in 0 - 4 range
|
| 82 |
|
|
tstb %d1 //check for rmode
|
| 83 |
|
|
beqs SM_RN //if zero, rn mode
|
| 84 |
|
|
cmpib #0x3,%d1 //check for rp
|
| 85 |
|
|
beqs SM_RP //if 3, rp mode
|
| 86 |
|
|
SM_RZRM:
|
| 87 |
|
|
leal SMALRZRM,%a0 //rmode is rz or rm, load SMRZRM in a0
|
| 88 |
|
|
cmpib #0x2,%d0 //check if result is inex
|
| 89 |
|
|
ble set_finx //if 0 - 2, it is inexact
|
| 90 |
|
|
bra no_finx //if 3, it is exact
|
| 91 |
|
|
SM_RN:
|
| 92 |
|
|
leal SMALRN,%a0 //rmode is rn, load SMRN in a0
|
| 93 |
|
|
cmpib #0x2,%d0 //check if result is inex
|
| 94 |
|
|
ble set_finx //if 0 - 2, it is inexact
|
| 95 |
|
|
bra no_finx //if 3, it is exact
|
| 96 |
|
|
SM_RP:
|
| 97 |
|
|
leal SMALRP,%a0 //rmode is rp, load SMRP in a0
|
| 98 |
|
|
cmpib #0x2,%d0 //check if result is inex
|
| 99 |
|
|
ble set_finx //if 0 - 2, it is inexact
|
| 100 |
|
|
bra no_finx //if 3, it is exact
|
| 101 |
|
|
BG_TBL:
|
| 102 |
|
|
subil #0x30,%d0 //make offset in 0 - f range
|
| 103 |
|
|
tstb %d1 //check for rmode
|
| 104 |
|
|
beqs BG_RN //if zero, rn mode
|
| 105 |
|
|
cmpib #0x3,%d1 //check for rp
|
| 106 |
|
|
beqs BG_RP //if 3, rp mode
|
| 107 |
|
|
BG_RZRM:
|
| 108 |
|
|
leal BIGRZRM,%a0 //rmode is rz or rm, load BGRZRM in a0
|
| 109 |
|
|
cmpib #0x1,%d0 //check if result is inex
|
| 110 |
|
|
ble set_finx //if 0 - 1, it is inexact
|
| 111 |
|
|
cmpib #0x7,%d0 //second check
|
| 112 |
|
|
ble no_finx //if 0 - 7, it is exact
|
| 113 |
|
|
bra set_finx //if 8 - f, it is inexact
|
| 114 |
|
|
BG_RN:
|
| 115 |
|
|
leal BIGRN,%a0 //rmode is rn, load BGRN in a0
|
| 116 |
|
|
cmpib #0x1,%d0 //check if result is inex
|
| 117 |
|
|
ble set_finx //if 0 - 1, it is inexact
|
| 118 |
|
|
cmpib #0x7,%d0 //second check
|
| 119 |
|
|
ble no_finx //if 0 - 7, it is exact
|
| 120 |
|
|
bra set_finx //if 8 - f, it is inexact
|
| 121 |
|
|
BG_RP:
|
| 122 |
|
|
leal BIGRP,%a0 //rmode is rp, load SMRP in a0
|
| 123 |
|
|
cmpib #0x1,%d0 //check if result is inex
|
| 124 |
|
|
ble set_finx //if 0 - 1, it is inexact
|
| 125 |
|
|
cmpib #0x7,%d0 //second check
|
| 126 |
|
|
ble no_finx //if 0 - 7, it is exact
|
| 127 |
|
|
// bra set_finx ;if 8 - f, it is inexact
|
| 128 |
|
|
set_finx:
|
| 129 |
|
|
orl #inx2a_mask,USER_FPSR(%a6) //set inex2/ainex
|
| 130 |
|
|
no_finx:
|
| 131 |
|
|
mulul #12,%d0 //use offset to point into tables
|
| 132 |
|
|
movel %d1,L_SCR1(%a6) //load mode for round call
|
| 133 |
|
|
bfextu USER_FPCR(%a6){#24:#2},%d1 //get precision
|
| 134 |
|
|
tstl %d1 //check if extended precision
|
| 135 |
|
|
//
|
| 136 |
|
|
// Precision is extended
|
| 137 |
|
|
//
|
| 138 |
|
|
bnes not_ext //if extended, do not call round
|
| 139 |
|
|
fmovemx (%a0,%d0),%fp0-%fp0 //return result in fp0
|
| 140 |
|
|
rts
|
| 141 |
|
|
//
|
| 142 |
|
|
// Precision is single or double
|
| 143 |
|
|
//
|
| 144 |
|
|
not_ext:
|
| 145 |
|
|
swap %d1 //rnd prec in upper word of d1
|
| 146 |
|
|
addl L_SCR1(%a6),%d1 //merge rmode in low word of d1
|
| 147 |
|
|
movel (%a0,%d0),FP_SCR1(%a6) //load first word to temp storage
|
| 148 |
|
|
movel 4(%a0,%d0),FP_SCR1+4(%a6) //load second word
|
| 149 |
|
|
movel 8(%a0,%d0),FP_SCR1+8(%a6) //load third word
|
| 150 |
|
|
clrl %d0 //clear g,r,s
|
| 151 |
|
|
lea FP_SCR1(%a6),%a0
|
| 152 |
|
|
btstb #sign_bit,LOCAL_EX(%a0)
|
| 153 |
|
|
sne LOCAL_SGN(%a0) //convert to internal ext. format
|
| 154 |
|
|
|
| 155 |
|
|
bsr round //go round the mantissa
|
| 156 |
|
|
|
| 157 |
|
|
bfclr LOCAL_SGN(%a0){#0:#8} //convert back to IEEE ext format
|
| 158 |
|
|
beqs fin_fcr
|
| 159 |
|
|
bsetb #sign_bit,LOCAL_EX(%a0)
|
| 160 |
|
|
fin_fcr:
|
| 161 |
|
|
fmovemx (%a0),%fp0-%fp0
|
| 162 |
|
|
rts
|
| 163 |
|
|
|
| 164 |
|
|
|end
|
