arch/m68k/fpsp040/smovecr.S

   1 |
   2 |       smovecr.sa 3.1 12/10/90
   3 |
   4 |       The entry point sMOVECR returns the constant at the
   5 |       offset given in the instruction field.
   6 |
   7 |       Input: An offset in the instruction word.
   8 |
   9 |       Output: The constant rounded to the user's rounding
  10 |               mode unchecked for overflow.
  11 |
  12 |       Modified: fp0.
  13 |
  14 |
  15 |               Copyright (C) Motorola, Inc. 1990
  16 |                       All Rights Reserved
  17 |
  18 |       For details on the license for this file, please see the
  19 |       file, README, in this same directory.
  20
  21 |SMOVECR        idnt    2,1 | Motorola 040 Floating Point Software Package
  22
  23         |section 8
  24
  25 #include "fpsp.h"
  26
  27         |xref   nrm_set
  28         |xref   round
  29         |xref   PIRN
  30         |xref   PIRZRM
  31         |xref   PIRP
  32         |xref   SMALRN
  33         |xref   SMALRZRM
  34         |xref   SMALRP
  35         |xref   BIGRN
  36         |xref   BIGRZRM
  37         |xref   BIGRP
  38
  39 FZERO:  .long   00000000
  40 |
  41 |       FMOVECR
  42 |
  43         .global smovcr
  44 smovcr:
  45         bfextu  CMDREG1B(%a6){#9:#7},%d0 |get offset
  46         bfextu  USER_FPCR(%a6){#26:#2},%d1 |get rmode
  47 |
  48 | check range of offset
  49 |
  50         tstb    %d0             |if zero, offset is to pi
  51         beqs    PI_TBL          |it is pi
  52         cmpib   #0x0a,%d0               |check range $01 - $0a
  53         bles    Z_VAL           |if in this range, return zero
  54         cmpib   #0x0e,%d0               |check range $0b - $0e
  55         bles    SM_TBL          |valid constants in this range
  56         cmpib   #0x2f,%d0               |check range $10 - $2f
  57         bles    Z_VAL           |if in this range, return zero
  58         cmpib   #0x3f,%d0               |check range $30 - $3f
  59         ble     BG_TBL          |valid constants in this range
  60 Z_VAL:
  61         fmoves  FZERO,%fp0
  62         rts
  63 PI_TBL:
  64         tstb    %d1             |offset is zero, check for rmode
  65         beqs    PI_RN           |if zero, rn mode
  66         cmpib   #0x3,%d1                |check for rp
  67         beqs    PI_RP           |if 3, rp mode
  68 PI_RZRM:
  69         leal    PIRZRM,%a0      |rmode is rz or rm, load PIRZRM in a0
  70         bra     set_finx
  71 PI_RN:
  72         leal    PIRN,%a0                |rmode is rn, load PIRN in a0
  73         bra     set_finx
  74 PI_RP:
  75         leal    PIRP,%a0                |rmode is rp, load PIRP in a0
  76         bra     set_finx
  77 SM_TBL:
  78         subil   #0xb,%d0                |make offset in 0 - 4 range
  79         tstb    %d1             |check for rmode
  80         beqs    SM_RN           |if zero, rn mode
  81         cmpib   #0x3,%d1                |check for rp
  82         beqs    SM_RP           |if 3, rp mode
  83 SM_RZRM:
  84         leal    SMALRZRM,%a0    |rmode is rz or rm, load SMRZRM in a0
  85         cmpib   #0x2,%d0                |check if result is inex
  86         ble     set_finx        |if 0 - 2, it is inexact
  87         bra     no_finx         |if 3, it is exact
  88 SM_RN:
  89         leal    SMALRN,%a0      |rmode is rn, load SMRN in a0
  90         cmpib   #0x2,%d0                |check if result is inex
  91         ble     set_finx        |if 0 - 2, it is inexact
  92         bra     no_finx         |if 3, it is exact
  93 SM_RP:
  94         leal    SMALRP,%a0      |rmode is rp, load SMRP in a0
  95         cmpib   #0x2,%d0                |check if result is inex
  96         ble     set_finx        |if 0 - 2, it is inexact
  97         bra     no_finx         |if 3, it is exact
  98 BG_TBL:
  99         subil   #0x30,%d0               |make offset in 0 - f range
 100         tstb    %d1             |check for rmode
 101         beqs    BG_RN           |if zero, rn mode
 102         cmpib   #0x3,%d1                |check for rp
 103         beqs    BG_RP           |if 3, rp mode
 104 BG_RZRM:
 105         leal    BIGRZRM,%a0     |rmode is rz or rm, load BGRZRM in a0
 106         cmpib   #0x1,%d0                |check if result is inex
 107         ble     set_finx        |if 0 - 1, it is inexact
 108         cmpib   #0x7,%d0                |second check
 109         ble     no_finx         |if 0 - 7, it is exact
 110         bra     set_finx        |if 8 - f, it is inexact
 111 BG_RN:
 112         leal    BIGRN,%a0       |rmode is rn, load BGRN in a0
 113         cmpib   #0x1,%d0                |check if result is inex
 114         ble     set_finx        |if 0 - 1, it is inexact
 115         cmpib   #0x7,%d0                |second check
 116         ble     no_finx         |if 0 - 7, it is exact
 117         bra     set_finx        |if 8 - f, it is inexact
 118 BG_RP:
 119         leal    BIGRP,%a0       |rmode is rp, load SMRP in a0
 120         cmpib   #0x1,%d0                |check if result is inex
 121         ble     set_finx        |if 0 - 1, it is inexact
 122         cmpib   #0x7,%d0                |second check
 123         ble     no_finx         |if 0 - 7, it is exact
 124 |       bra     set_finx        ;if 8 - f, it is inexact
 125 set_finx:
 126         orl     #inx2a_mask,USER_FPSR(%a6) |set inex2/ainex
 127 no_finx:
 128         mulul   #12,%d0                 |use offset to point into tables
 129         movel   %d1,L_SCR1(%a6)         |load mode for round call
 130         bfextu  USER_FPCR(%a6){#24:#2},%d1      |get precision
 131         tstl    %d1                     |check if extended precision
 132 |
 133 | Precision is extended
 134 |
 135         bnes    not_ext                 |if extended, do not call round
 136         fmovemx (%a0,%d0),%fp0-%fp0             |return result in fp0
 137         rts
 138 |
 139 | Precision is single or double
 140 |
 141 not_ext:
 142         swap    %d1                     |rnd prec in upper word of d1
 143         addl    L_SCR1(%a6),%d1         |merge rmode in low word of d1
 144         movel   (%a0,%d0),FP_SCR1(%a6)  |load first word to temp storage
 145         movel   4(%a0,%d0),FP_SCR1+4(%a6)       |load second word
 146         movel   8(%a0,%d0),FP_SCR1+8(%a6)       |load third word
 147         clrl    %d0                     |clear g,r,s
 148         lea     FP_SCR1(%a6),%a0
 149         btstb   #sign_bit,LOCAL_EX(%a0)
 150         sne     LOCAL_SGN(%a0)          |convert to internal ext. format
 151
 152         bsr     round                   |go round the mantissa
 153
 154         bfclr   LOCAL_SGN(%a0){#0:#8}   |convert back to IEEE ext format
 155         beqs    fin_fcr
 156         bsetb   #sign_bit,LOCAL_EX(%a0)
 157 fin_fcr:
 158         fmovemx (%a0),%fp0-%fp0
 159         rts
 160
 161         |end