smovecr.sa revision 1.1
1 * MOTOROLA MICROPROCESSOR & MEMORY TECHNOLOGY GROUP 2 * M68000 Hi-Performance Microprocessor Division 3 * M68040 Software Package 4 * 5 * M68040 Software Package Copyright (c) 1993, 1994 Motorola Inc. 6 * All rights reserved. 7 * 8 * THE SOFTWARE is provided on an "AS IS" basis and without warranty. 9 * To the maximum extent permitted by applicable law, 10 * MOTOROLA DISCLAIMS ALL WARRANTIES WHETHER EXPRESS OR IMPLIED, 11 * INCLUDING IMPLIED WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A 12 * PARTICULAR PURPOSE and any warranty against infringement with 13 * regard to the SOFTWARE (INCLUDING ANY MODIFIED VERSIONS THEREOF) 14 * and any accompanying written materials. 15 * 16 * To the maximum extent permitted by applicable law, 17 * IN NO EVENT SHALL MOTOROLA BE LIABLE FOR ANY DAMAGES WHATSOEVER 18 * (INCLUDING WITHOUT LIMITATION, DAMAGES FOR LOSS OF BUSINESS 19 * PROFITS, BUSINESS INTERRUPTION, LOSS OF BUSINESS INFORMATION, OR 20 * OTHER PECUNIARY LOSS) ARISING OF THE USE OR INABILITY TO USE THE 21 * SOFTWARE. Motorola assumes no responsibility for the maintenance 22 * and support of the SOFTWARE. 23 * 24 * You are hereby granted a copyright license to use, modify, and 25 * distribute the SOFTWARE so long as this entire notice is retained 26 * without alteration in any modified and/or redistributed versions, 27 * and that such modified versions are clearly identified as such. 28 * No licenses are granted by implication, estoppel or otherwise 29 * under any patents or trademarks of Motorola, Inc. 30 31 * 32 * smovecr.sa 3.1 12/10/90 33 * 34 * The entry point sMOVECR returns the constant at the 35 * offset given in the instruction field. 36 * 37 * Input: An offset in the instruction word. 38 * 39 * Output: The constant rounded to the user's rounding 40 * mode unchecked for overflow. 41 * 42 * Modified: fp0. 43 * 44 45 SMOVECR IDNT 2,1 Motorola 040 Floating Point Software Package 46 47 section 8 48 49 include fpsp.h 50 51 xref nrm_set 52 xref round 53 xref PIRN 54 xref PIRZRM 55 xref PIRP 56 xref SMALRN 57 xref SMALRZRM 58 xref SMALRP 59 xref BIGRN 60 xref BIGRZRM 61 xref BIGRP 62 63 FZERO dc.l 00000000 64 * 65 * FMOVECR 66 * 67 xdef smovcr 68 smovcr: 69 bfextu CMDREG1B(a6){9:7},d0 ;get offset 70 bfextu USER_FPCR(a6){26:2},d1 ;get rmode 71 * 72 * check range of offset 73 * 74 tst.b d0 ;if zero, offset is to pi 75 beq.b PI_TBL ;it is pi 76 cmpi.b #$0a,d0 ;check range $01 - $0a 77 ble.b Z_VAL ;if in this range, return zero 78 cmpi.b #$0e,d0 ;check range $0b - $0e 79 ble.b SM_TBL ;valid constants in this range 80 cmpi.b #$2f,d0 ;check range $10 - $2f 81 ble.b Z_VAL ;if in this range, return zero 82 cmpi.b #$3f,d0 ;check range $30 - $3f 83 ble BG_TBL ;valid constants in this range 84 Z_VAL: 85 fmove.s FZERO,fp0 86 rts 87 PI_TBL: 88 tst.b d1 ;offset is zero, check for rmode 89 beq.b PI_RN ;if zero, rn mode 90 cmpi.b #$3,d1 ;check for rp 91 beq.b PI_RP ;if 3, rp mode 92 PI_RZRM: 93 lea.l PIRZRM,a0 ;rmode is rz or rm, load PIRZRM in a0 94 bra set_finx 95 PI_RN: 96 lea.l PIRN,a0 ;rmode is rn, load PIRN in a0 97 bra set_finx 98 PI_RP: 99 lea.l PIRP,a0 ;rmode is rp, load PIRP in a0 100 bra set_finx 101 SM_TBL: 102 subi.l #$b,d0 ;make offset in 0 - 4 range 103 tst.b d1 ;check for rmode 104 beq.b SM_RN ;if zero, rn mode 105 cmpi.b #$3,d1 ;check for rp 106 beq.b SM_RP ;if 3, rp mode 107 SM_RZRM: 108 lea.l SMALRZRM,a0 ;rmode is rz or rm, load SMRZRM in a0 109 cmpi.b #$2,d0 ;check if result is inex 110 ble set_finx ;if 0 - 2, it is inexact 111 bra no_finx ;if 3, it is exact 112 SM_RN: 113 lea.l SMALRN,a0 ;rmode is rn, load SMRN in a0 114 cmpi.b #$2,d0 ;check if result is inex 115 ble set_finx ;if 0 - 2, it is inexact 116 bra no_finx ;if 3, it is exact 117 SM_RP: 118 lea.l SMALRP,a0 ;rmode is rp, load SMRP in a0 119 cmpi.b #$2,d0 ;check if result is inex 120 ble set_finx ;if 0 - 2, it is inexact 121 bra no_finx ;if 3, it is exact 122 BG_TBL: 123 subi.l #$30,d0 ;make offset in 0 - f range 124 tst.b d1 ;check for rmode 125 beq.b BG_RN ;if zero, rn mode 126 cmpi.b #$3,d1 ;check for rp 127 beq.b BG_RP ;if 3, rp mode 128 BG_RZRM: 129 lea.l BIGRZRM,a0 ;rmode is rz or rm, load BGRZRM in a0 130 cmpi.b #$1,d0 ;check if result is inex 131 ble set_finx ;if 0 - 1, it is inexact 132 cmpi.b #$7,d0 ;second check 133 ble no_finx ;if 0 - 7, it is exact 134 bra set_finx ;if 8 - f, it is inexact 135 BG_RN: 136 lea.l BIGRN,a0 ;rmode is rn, load BGRN in a0 137 cmpi.b #$1,d0 ;check if result is inex 138 ble set_finx ;if 0 - 1, it is inexact 139 cmpi.b #$7,d0 ;second check 140 ble no_finx ;if 0 - 7, it is exact 141 bra set_finx ;if 8 - f, it is inexact 142 BG_RP: 143 lea.l BIGRP,a0 ;rmode is rp, load SMRP in a0 144 cmpi.b #$1,d0 ;check if result is inex 145 ble set_finx ;if 0 - 1, it is inexact 146 cmpi.b #$7,d0 ;second check 147 ble no_finx ;if 0 - 7, it is exact 148 * bra set_finx ;if 8 - f, it is inexact 149 set_finx: 150 or.l #inx2a_mask,USER_FPSR(a6) ;set inex2/ainex 151 no_finx: 152 mulu.l #12,d0 ;use offset to point into tables 153 move.l d1,L_SCR1(a6) ;load mode for round call 154 bfextu USER_FPCR(a6){24:2},d1 ;get precision 155 tst.l d1 ;check if extended precision 156 * 157 * Precision is extended 158 * 159 bne.b not_ext ;if extended, do not call round 160 fmovem.x (a0,d0),fp0 ;return result in fp0 161 rts 162 * 163 * Precision is single or double 164 * 165 not_ext: 166 swap d1 ;rnd prec in upper word of d1 167 add.l L_SCR1(a6),d1 ;merge rmode in low word of d1 168 move.l (a0,d0),FP_SCR1(a6) ;load first word to temp storage 169 move.l 4(a0,d0),FP_SCR1+4(a6) ;load second word 170 move.l 8(a0,d0),FP_SCR1+8(a6) ;load third word 171 clr.l d0 ;clear g,r,s 172 lea FP_SCR1(a6),a0 173 btst.b #sign_bit,LOCAL_EX(a0) 174 sne LOCAL_SGN(a0) ;convert to internal ext. format 175 176 bsr round ;go round the mantissa 177 178 bfclr LOCAL_SGN(a0){0:8} ;convert back to IEEE ext format 179 beq.b fin_fcr 180 bset.b #sign_bit,LOCAL_EX(a0) 181 fin_fcr: 182 fmovem.x (a0),fp0 183 rts 184 185 end 186
Indexes created Wed Oct 29 09:09:48 GMT 2025