1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
|
/*
* $XConsortium: stipmips.s,v 1.10 94/04/17 20:29:08 keith Exp $
*
Copyright (c) 1990 X Consortium
Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:
The above copyright notice and this permission notice shall be included in
all copies or substantial portions of the Software.
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
X CONSORTIUM BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
Except as contained in this notice, the name of the X Consortium shall not be
used in advertising or otherwise to promote the sale, use or other dealings
in this Software without prior written authorization from the X Consortium.
*
* Author: Keith Packard, MIT X Consortium
*/
/*
* MIPS assembly code for optimized text rendering.
*
* Other stippling could be done in assembly, but the payoff is
* not nearly as large. Mostly because large areas are heavily
* optimized already.
*/
#ifdef MIPSEL
# define BitsR sll
# define BitsL srl
# define BO(o) o
# define HO(o) o
# define WO(o) o
# define FourBits(dest,bits) and dest, bits, 0xf
#else
# define BitsR srl
# define BitsL sll
# define BO(o) 3-o
# define HO(o) 2-o
# define WO(o) o
# define FourBits(dest,bits) srl dest, bits, 28
#endif
/* reordering instructions would be fatal here */
.set noreorder
/*
* cfbStippleStack(addr, stipple, value, stride, Count, Shift)
* 4 5 6 7 16(sp) 20(sp)
*
* Apply successive 32-bit stipples starting at addr, addr+stride, ...
*
* Used for text rendering, but only when no data could be lost
* when the stipple is shifted left by Shift bits
*/
/* arguments */
#define addr $4
#define stipple $5
#define value $6
#define stride $7
#define Count 16($sp)
#define Shift 20($sp)
/* local variables */
#define count $14
#define shift $13
#define atemp $12
#define bits $11
#define lshift $9
#define sbase $8
#define stemp $2
#define CASE_SIZE 5 /* case blocks are 2^5 bytes each */
#define CASE_MASK 0x1e0 /* first case mask */
#define ForEachLine $200
#define NextLine $201
#define NextLine1 $202
#define CaseBegin $203
#define ForEachBits $204
#define ForEachBits1 $205
#define NextBits $206
#ifdef TETEXT
#define cfbStippleStack cfbStippleStackTE
#endif
.globl cfbStippleStack
.ent cfbStippleStack 2
cfbStippleStack:
.frame $sp, 0, $31
lw count, Count /* fetch stack params */
la sbase,CaseBegin /* load up switch table */
lw shift, Shift
li lshift, 4 /* compute offset within */
subu lshift, lshift, shift /* stipple of remaining bits */
#ifdef MIPSEL
addu shift, shift, CASE_SIZE /* first shift for LSB */
#else
addu shift, shift, 28-CASE_SIZE /* first shift for MSB */
#endif
/* do ... while (--count > 0); */
ForEachLine:
lw bits, 0(stipple) /* get stipple bits */
move atemp, addr /* set up for this line */
#ifdef TETEXT
/* Terminal emulator fonts are expanded and have many 0 rows */
beqz bits, NextLine /* skip out early on 0 */
#endif
addu addr, addr, stride /* step for the loop */
BitsR stemp, bits, shift /* get first bits */
and stemp, stemp, CASE_MASK /* compute first branch */
addu stemp, stemp, sbase /* ... */
j stemp /* ... */
BitsL bits, bits, lshift /* set remaining bits */
ForEachBits:
addu atemp, atemp, 4
ForEachBits1:
FourBits(stemp, bits) /* compute jump for */
sll stemp, stemp, CASE_SIZE /* next four bits */
addu stemp, stemp, sbase /* ... */
j stemp /* ... */
BitsL bits, bits, 4 /* step for remaining bits */
CaseBegin:
bnez bits, ForEachBits1 /* 0 */
addu atemp, atemp, 4
NextLine:
addu count, count, -1
bnez count, ForEachLine
addu stipple, stipple, 4
j $31
nop
nop
bnez bits, ForEachBits /* 1 */
sb value, BO(0)(atemp)
addu count, count, -1
bnez count, ForEachLine
addu stipple, stipple, 4
j $31
nop
nop
bnez bits, ForEachBits /* 2 */
sb value, BO(1)(atemp)
addu count, count, -1
bnez count, ForEachLine
addu stipple, stipple, 4
j $31
nop
nop
bnez bits, ForEachBits /* 3 */
sh value, HO(0)(atemp)
addu count, count, -1
bnez count, ForEachLine
addu stipple, stipple, 4
j $31
nop
nop
bnez bits, ForEachBits /* 4 */
sb value, BO(2)(atemp)
addu count, count, -1
bnez count, ForEachLine
addu stipple, stipple, 4
j $31
nop
nop
sb value, BO(0)(atemp) /* 5 */
bnez bits, ForEachBits
sb value, BO(2)(atemp)
addu count, count, -1
bnez count, ForEachLine
addu stipple, stipple, 4
j $31
nop
sb value, BO(1)(atemp) /* 6 */
bnez bits, ForEachBits
sb value, BO(2)(atemp)
addu count, count, -1
bnez count, ForEachLine
addu stipple, stipple, 4
j $31
nop
bnez bits, ForEachBits /* 7 */
swl value, BO(2)(atemp) /* untested on MSB */
addu count, count, -1
bnez count, ForEachLine
addu stipple, stipple, 4
j $31
nop
nop
bnez bits, ForEachBits /* 8 */
sb value, BO(3)(atemp)
addu count, count, -1
bnez count, ForEachLine
addu stipple, stipple, 4
j $31
nop
nop
sb value, BO(0)(atemp) /* 9 */
bnez bits, ForEachBits
sb value, BO(3)(atemp)
addu count, count, -1
bnez count, ForEachLine
addu stipple, stipple, 4
j $31
nop
sb value, BO(1)(atemp) /* a */
bnez bits, ForEachBits
sb value, BO(3)(atemp)
addu count, count, -1
bnez count, ForEachLine
addu stipple, stipple, 4
j $31
nop
sh value, HO(0)(atemp) /* b */
bnez bits, ForEachBits
sb value, BO(3)(atemp)
addu count, count, -1
bnez count, ForEachLine
addu stipple, stipple, 4
j $31
nop
bnez bits, ForEachBits /* c */
sh value, HO(2)(atemp)
addu count, count, -1
bnez count, ForEachLine
addu stipple, stipple, 4
j $31
nop
nop
sb value, BO(0)(atemp) /* d */
bnez bits, ForEachBits
sh value, HO(2)(atemp)
addu count, count, -1
bnez count, ForEachLine
addu stipple, stipple, 4
j $31
nop
bnez bits, ForEachBits /* e */
swr value, BO(1)(atemp) /* untested on MSB */
addu count, count, -1
bnez count, ForEachLine
addu stipple, stipple, 4
j $31
nop
nop
bnez bits, ForEachBits /* f */
sw value, WO(0)(atemp)
addu count, count, -1
bnez count, ForEachLine
addu stipple, stipple, 4
j $31
nop
nop
.end cfbStippleStack
|
