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xianfeng |
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| smovecr.sa 3.1 12/10/90
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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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| Input: An offset in the instruction word.
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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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| Modified: fp0.
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| Copyright (C) Motorola, Inc. 1990
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| All Rights Reserved
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| For details on the license for this file, please see the
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| file, README, in this same directory.
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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: .long 00000000
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| FMOVECR
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.global 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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| check range of offset
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tstb %d0 |if zero, offset is to pi
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beqs PI_TBL |it is pi
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cmpib #0x0a,%d0 |check range $01 - $0a
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bles Z_VAL |if in this range, return zero
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cmpib #0x0e,%d0 |check range $0b - $0e
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bles SM_TBL |valid constants in this range
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cmpib #0x2f,%d0 |check range $10 - $2f
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bles Z_VAL |if in this range, return zero
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cmpib #0x3f,%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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fmoves FZERO,%fp0
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rts
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PI_TBL:
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tstb %d1 |offset is zero, check for rmode
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beqs PI_RN |if zero, rn mode
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cmpib #0x3,%d1 |check for rp
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beqs PI_RP |if 3, rp mode
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PI_RZRM:
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leal 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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leal 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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leal 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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subil #0xb,%d0 |make offset in 0 - 4 range
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tstb %d1 |check for rmode
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beqs SM_RN |if zero, rn mode
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cmpib #0x3,%d1 |check for rp
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beqs SM_RP |if 3, rp mode
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SM_RZRM:
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leal SMALRZRM,%a0 |rmode is rz or rm, load SMRZRM in a0
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cmpib #0x2,%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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leal SMALRN,%a0 |rmode is rn, load SMRN in a0
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cmpib #0x2,%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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leal SMALRP,%a0 |rmode is rp, load SMRP in a0
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cmpib #0x2,%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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subil #0x30,%d0 |make offset in 0 - f range
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tstb %d1 |check for rmode
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beqs BG_RN |if zero, rn mode
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cmpib #0x3,%d1 |check for rp
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beqs BG_RP |if 3, rp mode
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BG_RZRM:
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leal BIGRZRM,%a0 |rmode is rz or rm, load BGRZRM in a0
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cmpib #0x1,%d0 |check if result is inex
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ble set_finx |if 0 - 1, it is inexact
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cmpib #0x7,%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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leal BIGRN,%a0 |rmode is rn, load BGRN in a0
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cmpib #0x1,%d0 |check if result is inex
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ble set_finx |if 0 - 1, it is inexact
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cmpib #0x7,%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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leal BIGRP,%a0 |rmode is rp, load SMRP in a0
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cmpib #0x1,%d0 |check if result is inex
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ble set_finx |if 0 - 1, it is inexact
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cmpib #0x7,%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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orl #inx2a_mask,USER_FPSR(%a6) |set inex2/ainex
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no_finx:
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mulul #12,%d0 |use offset to point into tables
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movel %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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tstl %d1 |check if extended precision
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| Precision is extended
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bnes not_ext |if extended, do not call round
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fmovemx (%a0,%d0),%fp0-%fp0 |return result in fp0
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rts
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| Precision is single or double
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not_ext:
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swap %d1 |rnd prec in upper word of d1
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addl L_SCR1(%a6),%d1 |merge rmode in low word of d1
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movel (%a0,%d0),FP_SCR1(%a6) |load first word to temp storage
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movel 4(%a0,%d0),FP_SCR1+4(%a6) |load second word
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movel 8(%a0,%d0),FP_SCR1+8(%a6) |load third word
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clrl %d0 |clear g,r,s
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lea FP_SCR1(%a6),%a0
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btstb #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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beqs fin_fcr
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bsetb #sign_bit,LOCAL_EX(%a0)
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fin_fcr:
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fmovemx (%a0),%fp0-%fp0
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rts
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|end
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