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//
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// $Id: smovecr.S,v 1.2 2001-09-27 12:01:22 chris Exp $
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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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//
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// Copyright (C) Motorola, Inc. 1990
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// All Rights Reserved
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//
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// THIS IS UNPUBLISHED PROPRIETARY SOURCE CODE OF MOTOROLA
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// The copyright notice above does not evidence any
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// actual or intended publication of such source code.
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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.defs"
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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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//
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// FMOVECR
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//
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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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//
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// check range of offset
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//
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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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//
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// Precision is extended
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//
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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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//
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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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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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