186 lines
5.4 KiB
Plaintext
186 lines
5.4 KiB
Plaintext
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* MOTOROLA MICROPROCESSOR & MEMORY TECHNOLOGY GROUP
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* M68000 Hi-Performance Microprocessor Division
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* M68040 Software Package
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*
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* M68040 Software Package Copyright (c) 1993, 1994 Motorola Inc.
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* All rights reserved.
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*
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* THE SOFTWARE is provided on an "AS IS" basis and without warranty.
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* To the maximum extent permitted by applicable law,
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* MOTOROLA DISCLAIMS ALL WARRANTIES WHETHER EXPRESS OR IMPLIED,
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* INCLUDING IMPLIED WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A
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* PARTICULAR PURPOSE and any warranty against infringement with
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* regard to the SOFTWARE (INCLUDING ANY MODIFIED VERSIONS THEREOF)
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* and any accompanying written materials.
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*
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* To the maximum extent permitted by applicable law,
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* IN NO EVENT SHALL MOTOROLA BE LIABLE FOR ANY DAMAGES WHATSOEVER
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* (INCLUDING WITHOUT LIMITATION, DAMAGES FOR LOSS OF BUSINESS
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* PROFITS, BUSINESS INTERRUPTION, LOSS OF BUSINESS INFORMATION, OR
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* OTHER PECUNIARY LOSS) ARISING OF THE USE OR INABILITY TO USE THE
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* SOFTWARE. Motorola assumes no responsibility for the maintenance
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* and support of the SOFTWARE.
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*
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* You are hereby granted a copyright license to use, modify, and
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* distribute the SOFTWARE so long as this entire notice is retained
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* without alteration in any modified and/or redistributed versions,
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* and that such modified versions are clearly identified as such.
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* No licenses are granted by implication, estoppel or otherwise
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* under any patents or trademarks of Motorola, Inc.
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*
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* smovecr.sa 3.1 12/10/90
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*
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* The entry point sMOVECR returns the constant at the
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* offset given in the instruction field.
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*
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* Input: An offset in the instruction word.
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*
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* Output: The constant rounded to the user's rounding
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* mode unchecked for overflow.
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*
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* Modified: fp0.
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*
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SMOVECR IDNT 2,1 Motorola 040 Floating Point Software Package
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section 8
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include fpsp.h
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xref nrm_set
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xref round
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xref PIRN
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xref PIRZRM
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xref PIRP
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xref SMALRN
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xref SMALRZRM
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xref SMALRP
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xref BIGRN
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xref BIGRZRM
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xref BIGRP
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FZERO dc.l 00000000
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*
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* FMOVECR
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*
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xdef smovcr
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smovcr:
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bfextu CMDREG1B(a6){9:7},d0 ;get offset
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bfextu USER_FPCR(a6){26:2},d1 ;get rmode
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*
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* check range of offset
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*
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tst.b d0 ;if zero, offset is to pi
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beq.b PI_TBL ;it is pi
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cmpi.b #$0a,d0 ;check range $01 - $0a
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ble.b Z_VAL ;if in this range, return zero
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cmpi.b #$0e,d0 ;check range $0b - $0e
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ble.b SM_TBL ;valid constants in this range
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cmpi.b #$2f,d0 ;check range $10 - $2f
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ble.b Z_VAL ;if in this range, return zero
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cmpi.b #$3f,d0 ;check range $30 - $3f
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ble BG_TBL ;valid constants in this range
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Z_VAL:
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fmove.s FZERO,fp0
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rts
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PI_TBL:
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tst.b d1 ;offset is zero, check for rmode
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beq.b PI_RN ;if zero, rn mode
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cmpi.b #$3,d1 ;check for rp
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beq.b PI_RP ;if 3, rp mode
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PI_RZRM:
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lea.l PIRZRM,a0 ;rmode is rz or rm, load PIRZRM in a0
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bra set_finx
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PI_RN:
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lea.l PIRN,a0 ;rmode is rn, load PIRN in a0
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bra set_finx
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PI_RP:
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lea.l PIRP,a0 ;rmode is rp, load PIRP in a0
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bra set_finx
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SM_TBL:
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subi.l #$b,d0 ;make offset in 0 - 4 range
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tst.b d1 ;check for rmode
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beq.b SM_RN ;if zero, rn mode
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cmpi.b #$3,d1 ;check for rp
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beq.b SM_RP ;if 3, rp mode
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SM_RZRM:
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lea.l SMALRZRM,a0 ;rmode is rz or rm, load SMRZRM in a0
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cmpi.b #$2,d0 ;check if result is inex
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ble set_finx ;if 0 - 2, it is inexact
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bra no_finx ;if 3, it is exact
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SM_RN:
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lea.l SMALRN,a0 ;rmode is rn, load SMRN in a0
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cmpi.b #$2,d0 ;check if result is inex
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ble set_finx ;if 0 - 2, it is inexact
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bra no_finx ;if 3, it is exact
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SM_RP:
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lea.l SMALRP,a0 ;rmode is rp, load SMRP in a0
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cmpi.b #$2,d0 ;check if result is inex
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ble set_finx ;if 0 - 2, it is inexact
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bra no_finx ;if 3, it is exact
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BG_TBL:
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subi.l #$30,d0 ;make offset in 0 - f range
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tst.b d1 ;check for rmode
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beq.b BG_RN ;if zero, rn mode
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cmpi.b #$3,d1 ;check for rp
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beq.b BG_RP ;if 3, rp mode
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BG_RZRM:
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lea.l BIGRZRM,a0 ;rmode is rz or rm, load BGRZRM in a0
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cmpi.b #$1,d0 ;check if result is inex
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ble set_finx ;if 0 - 1, it is inexact
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cmpi.b #$7,d0 ;second check
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ble no_finx ;if 0 - 7, it is exact
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bra set_finx ;if 8 - f, it is inexact
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BG_RN:
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lea.l BIGRN,a0 ;rmode is rn, load BGRN in a0
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cmpi.b #$1,d0 ;check if result is inex
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ble set_finx ;if 0 - 1, it is inexact
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cmpi.b #$7,d0 ;second check
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ble no_finx ;if 0 - 7, it is exact
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bra set_finx ;if 8 - f, it is inexact
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BG_RP:
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lea.l BIGRP,a0 ;rmode is rp, load SMRP in a0
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cmpi.b #$1,d0 ;check if result is inex
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ble set_finx ;if 0 - 1, it is inexact
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cmpi.b #$7,d0 ;second check
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ble no_finx ;if 0 - 7, it is exact
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* bra set_finx ;if 8 - f, it is inexact
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set_finx:
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or.l #inx2a_mask,USER_FPSR(a6) ;set inex2/ainex
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no_finx:
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mulu.l #12,d0 ;use offset to point into tables
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move.l d1,L_SCR1(a6) ;load mode for round call
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bfextu USER_FPCR(a6){24:2},d1 ;get precision
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tst.l d1 ;check if extended precision
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*
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* Precision is extended
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*
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bne.b not_ext ;if extended, do not call round
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fmovem.x (a0,d0),fp0 ;return result in fp0
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rts
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*
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* Precision is single or double
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*
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not_ext:
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swap d1 ;rnd prec in upper word of d1
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add.l L_SCR1(a6),d1 ;merge rmode in low word of d1
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move.l (a0,d0),FP_SCR1(a6) ;load first word to temp storage
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move.l 4(a0,d0),FP_SCR1+4(a6) ;load second word
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move.l 8(a0,d0),FP_SCR1+8(a6) ;load third word
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clr.l d0 ;clear g,r,s
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lea FP_SCR1(a6),a0
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btst.b #sign_bit,LOCAL_EX(a0)
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sne LOCAL_SGN(a0) ;convert to internal ext. format
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bsr round ;go round the mantissa
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bfclr LOCAL_SGN(a0){0:8} ;convert back to IEEE ext format
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beq.b fin_fcr
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bset.b #sign_bit,LOCAL_EX(a0)
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fin_fcr:
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fmovem.x (a0),fp0
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rts
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end
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