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