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