Annotation of sys/arch/m68k/fpsp/smovecr.sa, Revision 1.1
1.1 ! nbrk 1: * $OpenBSD: smovecr.sa,v 1.2 1996/05/29 21:05:40 niklas Exp $
! 2: * $NetBSD: smovecr.sa,v 1.2 1994/10/26 07:49:57 cgd Exp $
! 3:
! 4: * MOTOROLA MICROPROCESSOR & MEMORY TECHNOLOGY GROUP
! 5: * M68000 Hi-Performance Microprocessor Division
! 6: * M68040 Software Package
! 7: *
! 8: * M68040 Software Package Copyright (c) 1993, 1994 Motorola Inc.
! 9: * All rights reserved.
! 10: *
! 11: * THE SOFTWARE is provided on an "AS IS" basis and without warranty.
! 12: * To the maximum extent permitted by applicable law,
! 13: * MOTOROLA DISCLAIMS ALL WARRANTIES WHETHER EXPRESS OR IMPLIED,
! 14: * INCLUDING IMPLIED WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A
! 15: * PARTICULAR PURPOSE and any warranty against infringement with
! 16: * regard to the SOFTWARE (INCLUDING ANY MODIFIED VERSIONS THEREOF)
! 17: * and any accompanying written materials.
! 18: *
! 19: * To the maximum extent permitted by applicable law,
! 20: * IN NO EVENT SHALL MOTOROLA BE LIABLE FOR ANY DAMAGES WHATSOEVER
! 21: * (INCLUDING WITHOUT LIMITATION, DAMAGES FOR LOSS OF BUSINESS
! 22: * PROFITS, BUSINESS INTERRUPTION, LOSS OF BUSINESS INFORMATION, OR
! 23: * OTHER PECUNIARY LOSS) ARISING OF THE USE OR INABILITY TO USE THE
! 24: * SOFTWARE. Motorola assumes no responsibility for the maintenance
! 25: * and support of the SOFTWARE.
! 26: *
! 27: * You are hereby granted a copyright license to use, modify, and
! 28: * distribute the SOFTWARE so long as this entire notice is retained
! 29: * without alteration in any modified and/or redistributed versions,
! 30: * and that such modified versions are clearly identified as such.
! 31: * No licenses are granted by implication, estoppel or otherwise
! 32: * under any patents or trademarks of Motorola, Inc.
! 33:
! 34: *
! 35: * smovecr.sa 3.1 12/10/90
! 36: *
! 37: * The entry point sMOVECR returns the constant at the
! 38: * offset given in the instruction field.
! 39: *
! 40: * Input: An offset in the instruction word.
! 41: *
! 42: * Output: The constant rounded to the user's rounding
! 43: * mode unchecked for overflow.
! 44: *
! 45: * Modified: fp0.
! 46: *
! 47:
! 48: SMOVECR IDNT 2,1 Motorola 040 Floating Point Software Package
! 49:
! 50: section 8
! 51:
! 52: include fpsp.h
! 53:
! 54: xref nrm_set
! 55: xref round
! 56: xref PIRN
! 57: xref PIRZRM
! 58: xref PIRP
! 59: xref SMALRN
! 60: xref SMALRZRM
! 61: xref SMALRP
! 62: xref BIGRN
! 63: xref BIGRZRM
! 64: xref BIGRP
! 65:
! 66: FZERO dc.l 00000000
! 67: *
! 68: * FMOVECR
! 69: *
! 70: xdef smovcr
! 71: smovcr:
! 72: bfextu CMDREG1B(a6){9:7},d0 ;get offset
! 73: bfextu USER_FPCR(a6){26:2},d1 ;get rmode
! 74: *
! 75: * check range of offset
! 76: *
! 77: tst.b d0 ;if zero, offset is to pi
! 78: beq.b PI_TBL ;it is pi
! 79: cmpi.b #$0a,d0 ;check range $01 - $0a
! 80: ble.b Z_VAL ;if in this range, return zero
! 81: cmpi.b #$0e,d0 ;check range $0b - $0e
! 82: ble.b SM_TBL ;valid constants in this range
! 83: cmpi.b #$2f,d0 ;check range $10 - $2f
! 84: ble.b Z_VAL ;if in this range, return zero
! 85: cmpi.b #$3f,d0 ;check range $30 - $3f
! 86: ble BG_TBL ;valid constants in this range
! 87: Z_VAL:
! 88: fmove.s FZERO,fp0
! 89: rts
! 90: PI_TBL:
! 91: tst.b d1 ;offset is zero, check for rmode
! 92: beq.b PI_RN ;if zero, rn mode
! 93: cmpi.b #$3,d1 ;check for rp
! 94: beq.b PI_RP ;if 3, rp mode
! 95: PI_RZRM:
! 96: lea.l PIRZRM,a0 ;rmode is rz or rm, load PIRZRM in a0
! 97: bra set_finx
! 98: PI_RN:
! 99: lea.l PIRN,a0 ;rmode is rn, load PIRN in a0
! 100: bra set_finx
! 101: PI_RP:
! 102: lea.l PIRP,a0 ;rmode is rp, load PIRP in a0
! 103: bra set_finx
! 104: SM_TBL:
! 105: subi.l #$b,d0 ;make offset in 0 - 4 range
! 106: tst.b d1 ;check for rmode
! 107: beq.b SM_RN ;if zero, rn mode
! 108: cmpi.b #$3,d1 ;check for rp
! 109: beq.b SM_RP ;if 3, rp mode
! 110: SM_RZRM:
! 111: lea.l SMALRZRM,a0 ;rmode is rz or rm, load SMRZRM in a0
! 112: cmpi.b #$2,d0 ;check if result is inex
! 113: ble set_finx ;if 0 - 2, it is inexact
! 114: bra no_finx ;if 3, it is exact
! 115: SM_RN:
! 116: lea.l SMALRN,a0 ;rmode is rn, load SMRN in a0
! 117: cmpi.b #$2,d0 ;check if result is inex
! 118: ble set_finx ;if 0 - 2, it is inexact
! 119: bra no_finx ;if 3, it is exact
! 120: SM_RP:
! 121: lea.l SMALRP,a0 ;rmode is rp, load SMRP in a0
! 122: cmpi.b #$2,d0 ;check if result is inex
! 123: ble set_finx ;if 0 - 2, it is inexact
! 124: bra no_finx ;if 3, it is exact
! 125: BG_TBL:
! 126: subi.l #$30,d0 ;make offset in 0 - f range
! 127: tst.b d1 ;check for rmode
! 128: beq.b BG_RN ;if zero, rn mode
! 129: cmpi.b #$3,d1 ;check for rp
! 130: beq.b BG_RP ;if 3, rp mode
! 131: BG_RZRM:
! 132: lea.l BIGRZRM,a0 ;rmode is rz or rm, load BGRZRM in a0
! 133: cmpi.b #$1,d0 ;check if result is inex
! 134: ble set_finx ;if 0 - 1, it is inexact
! 135: cmpi.b #$7,d0 ;second check
! 136: ble no_finx ;if 0 - 7, it is exact
! 137: bra set_finx ;if 8 - f, it is inexact
! 138: BG_RN:
! 139: lea.l BIGRN,a0 ;rmode is rn, load BGRN in a0
! 140: cmpi.b #$1,d0 ;check if result is inex
! 141: ble set_finx ;if 0 - 1, it is inexact
! 142: cmpi.b #$7,d0 ;second check
! 143: ble no_finx ;if 0 - 7, it is exact
! 144: bra set_finx ;if 8 - f, it is inexact
! 145: BG_RP:
! 146: lea.l BIGRP,a0 ;rmode is rp, load SMRP in a0
! 147: cmpi.b #$1,d0 ;check if result is inex
! 148: ble set_finx ;if 0 - 1, it is inexact
! 149: cmpi.b #$7,d0 ;second check
! 150: ble no_finx ;if 0 - 7, it is exact
! 151: * bra set_finx ;if 8 - f, it is inexact
! 152: set_finx:
! 153: or.l #inx2a_mask,USER_FPSR(a6) ;set inex2/ainex
! 154: no_finx:
! 155: mulu.l #12,d0 ;use offset to point into tables
! 156: move.l d1,L_SCR1(a6) ;load mode for round call
! 157: bfextu USER_FPCR(a6){24:2},d1 ;get precision
! 158: tst.l d1 ;check if extended precision
! 159: *
! 160: * Precision is extended
! 161: *
! 162: bne.b not_ext ;if extended, do not call round
! 163: fmovem.x (a0,d0),fp0 ;return result in fp0
! 164: rts
! 165: *
! 166: * Precision is single or double
! 167: *
! 168: not_ext:
! 169: swap d1 ;rnd prec in upper word of d1
! 170: add.l L_SCR1(a6),d1 ;merge rmode in low word of d1
! 171: move.l (a0,d0),FP_SCR1(a6) ;load first word to temp storage
! 172: move.l 4(a0,d0),FP_SCR1+4(a6) ;load second word
! 173: move.l 8(a0,d0),FP_SCR1+8(a6) ;load third word
! 174: clr.l d0 ;clear g,r,s
! 175: lea FP_SCR1(a6),a0
! 176: btst.b #sign_bit,LOCAL_EX(a0)
! 177: sne LOCAL_SGN(a0) ;convert to internal ext. format
! 178:
! 179: bsr round ;go round the mantissa
! 180:
! 181: bfclr LOCAL_SGN(a0){0:8} ;convert back to IEEE ext format
! 182: beq.b fin_fcr
! 183: bset.b #sign_bit,LOCAL_EX(a0)
! 184: fin_fcr:
! 185: fmovem.x (a0),fp0
! 186: rts
! 187:
! 188: end
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