1 // Inferno utils/5l/pass.c
2 // http://code.google.com/p/inferno-os/source/browse/utils/5l/pass.c
3 //
4 // Copyright © 1994-1999 Lucent Technologies Inc. All rights reserved.
5 // Portions Copyright © 1995-1997 C H Forsyth (forsyth@terzarima.net)
6 // Portions Copyright © 1997-1999 Vita Nuova Limited
7 // Portions Copyright © 2000-2007 Vita Nuova Holdings Limited (www.vitanuova.com)
8 // Portions Copyright © 2004,2006 Bruce Ellis
9 // Portions Copyright © 2005-2007 C H Forsyth (forsyth@terzarima.net)
10 // Revisions Copyright © 2000-2007 Lucent Technologies Inc. and others
11 // Portions Copyright © 2009 The Go Authors. All rights reserved.
12 //
13 // Permission is hereby granted, free of charge, to any person obtaining a copy
14 // of this software and associated documentation files (the "Software"), to deal
15 // in the Software without restriction, including without limitation the rights
16 // to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
17 // copies of the Software, and to permit persons to whom the Software is
18 // furnished to do so, subject to the following conditions:
19 //
20 // The above copyright notice and this permission notice shall be included in
21 // all copies or substantial portions of the Software.
22 //
23 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
24 // IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
25 // FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
26 // AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
27 // LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
28 // OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
29 // THE SOFTWARE.
30
31 // Code and data passes.
32
33 #include "l.h"
34 #include "../ld/lib.h"
35
36 static void xfol(Prog*, Prog**);
37
38 Prog*
39 brchain(Prog *p)
40 {
41 int i;
42
43 for(i=0; i<20; i++) {
44 if(p == P || p->as != AB)
45 return p;
46 p = p->cond;
47 }
48 return P;
49 }
50
51 int
52 relinv(int a)
53 {
54 switch(a) {
55 case ABEQ: return ABNE;
56 case ABNE: return ABEQ;
57 case ABCS: return ABCC;
58 case ABHS: return ABLO;
59 case ABCC: return ABCS;
60 case ABLO: return ABHS;
61 case ABMI: return ABPL;
62 case ABPL: return ABMI;
63 case ABVS: return ABVC;
64 case ABVC: return ABVS;
65 case ABHI: return ABLS;
66 case ABLS: return ABHI;
67 case ABGE: return ABLT;
68 case ABLT: return ABGE;
69 case ABGT: return ABLE;
70 case ABLE: return ABGT;
71 }
72 diag("unknown relation: %s", anames[a]);
73 return a;
74 }
75
76 void
77 follow(void)
78 {
79 Prog *firstp, *lastp;
80
81 if(debug['v'])
82 Bprint(&bso, "%5.2f follow\n", cputime());
83 Bflush(&bso);
84
85 for(cursym = textp; cursym != nil; cursym = cursym->next) {
86 firstp = prg();
87 lastp = firstp;
88 xfol(cursym->text, &lastp);
89 lastp->link = nil;
90 cursym->text = firstp->link;
91 }
92 }
93
94 static void
95 xfol(Prog *p, Prog **last)
96 {
97 Prog *q, *r;
98 int a, i;
99
100 loop:
101 if(p == P)
102 return;
103 a = p->as;
104 if(a == AB) {
105 q = p->cond;
106 if(q != P && q->as != ATEXT) {
107 p->mark |= FOLL;
108 p = q;
109 if(!(p->mark & FOLL))
110 goto loop;
111 }
112 }
113 if(p->mark & FOLL) {
114 for(i=0,q=p; i<4; i++,q=q->link) {
115 if(q == *last || q == nil)
116 break;
117 a = q->as;
118 if(a == ANOP) {
119 i--;
120 continue;
121 }
122 if(a == AB || (a == ARET && q->scond == 14) || a == ARFE)
123 goto copy;
124 if(q->cond == P || (q->cond->mark&FOLL))
125 continue;
126 if(a != ABEQ && a != ABNE)
127 continue;
128 copy:
129 for(;;) {
130 r = prg();
131 *r = *p;
132 if(!(r->mark&FOLL))
133 print("cant happen 1\n");
134 r->mark |= FOLL;
135 if(p != q) {
136 p = p->link;
137 (*last)->link = r;
138 *last = r;
139 continue;
140 }
141 (*last)->link = r;
142 *last = r;
143 if(a == AB || (a == ARET && q->scond == 14) || a == ARFE)
144 return;
145 r->as = ABNE;
146 if(a == ABNE)
147 r->as = ABEQ;
148 r->cond = p->link;
149 r->link = p->cond;
150 if(!(r->link->mark&FOLL))
151 xfol(r->link, last);
152 if(!(r->cond->mark&FOLL))
153 print("cant happen 2\n");
154 return;
155 }
156 }
157 a = AB;
158 q = prg();
159 q->as = a;
160 q->line = p->line;
161 q->to.type = D_BRANCH;
162 q->to.offset = p->pc;
163 q->cond = p;
164 p = q;
165 }
166 p->mark |= FOLL;
167 (*last)->link = p;
168 *last = p;
169 if(a == AB || (a == ARET && p->scond == 14) || a == ARFE){
170 return;
171 }
172 if(p->cond != P)
173 if(a != ABL && a != ABX && p->link != P) {
174 q = brchain(p->link);
175 if(a != ATEXT && a != ABCASE)
176 if(q != P && (q->mark&FOLL)) {
177 p->as = relinv(a);
178 p->link = p->cond;
179 p->cond = q;
180 }
181 xfol(p->link, last);
182 q = brchain(p->cond);
183 if(q == P)
184 q = p->cond;
185 if(q->mark&FOLL) {
186 p->cond = q;
187 return;
188 }
189 p = q;
190 goto loop;
191 }
192 p = p->link;
193 goto loop;
194 }
195
196 void
197 patch(void)
198 {
199 int32 c, vexit;
200 Prog *p, *q;
201 Sym *s;
202 int a;
203
204 if(debug['v'])
205 Bprint(&bso, "%5.2f patch\n", cputime());
206 Bflush(&bso);
207 mkfwd();
208 s = lookup("exit", 0);
209 vexit = s->value;
210 for(cursym = textp; cursym != nil; cursym = cursym->next) {
211 for(p = cursym->text; p != P; p = p->link) {
212 a = p->as;
213 if((a == ABL || a == ABX || a == AB || a == ARET) &&
214 p->to.type != D_BRANCH && p->to.sym != S) {
215 s = p->to.sym;
216 switch(s->type) {
217 default:
218 diag("undefined: %s", s->name);
219 s->type = STEXT;
220 s->value = vexit;
221 continue; // avoid more error messages
222 case STEXT:
223 p->to.offset = s->value;
224 p->to.type = D_BRANCH;
225 break;
226 }
227 }
228 if(p->to.type != D_BRANCH)
229 continue;
230 c = p->to.offset;
231 for(q = textp->text; q != P;) {
232 if(c == q->pc)
233 break;
234 if(q->forwd != P && c >= q->forwd->pc)
235 q = q->forwd;
236 else
237 q = q->link;
238 }
239 if(q == P) {
240 diag("branch out of range %d\n%P", c, p);
241 p->to.type = D_NONE;
242 }
243 p->cond = q;
244 }
245 }
246
247 for(cursym = textp; cursym != nil; cursym = cursym->next) {
248 for(p = cursym->text; p != P; p = p->link) {
249 if(p->cond != P) {
250 p->cond = brloop(p->cond);
251 if(p->cond != P)
252 if(p->to.type == D_BRANCH)
253 p->to.offset = p->cond->pc;
254 }
255 }
256 }
257 }
258
259 Prog*
260 brloop(Prog *p)
261 {
262 Prog *q;
263 int c;
264
265 for(c=0; p!=P;) {
266 if(p->as != AB)
267 return p;
268 q = p->cond;
269 if(q <= p) {
270 c++;
271 if(q == p || c > 5000)
272 break;
273 }
274 p = q;
275 }
276 return P;
277 }
278
279 int32
280 atolwhex(char *s)
281 {
282 int32 n;
283 int f;
284
285 n = 0;
286 f = 0;
287 while(*s == ' ' || *s == '\t')
288 s++;
289 if(*s == '-' || *s == '+') {
290 if(*s++ == '-')
291 f = 1;
292 while(*s == ' ' || *s == '\t')
293 s++;
294 }
295 if(s[0]=='0' && s[1]){
296 if(s[1]=='x' || s[1]=='X'){
297 s += 2;
298 for(;;){
299 if(*s >= '0' && *s <= '9')
300 n = n*16 + *s++ - '0';
301 else if(*s >= 'a' && *s <= 'f')
302 n = n*16 + *s++ - 'a' + 10;
303 else if(*s >= 'A' && *s <= 'F')
304 n = n*16 + *s++ - 'A' + 10;
305 else
306 break;
307 }
308 } else
309 while(*s >= '0' && *s <= '7')
310 n = n*8 + *s++ - '0';
311 } else
312 while(*s >= '0' && *s <= '9')
313 n = n*10 + *s++ - '0';
314 if(f)
315 n = -n;
316 return n;
317 }
318
319 int32
320 rnd(int32 v, int32 r)
321 {
322 int32 c;
323
324 if(r <= 0)
325 return v;
326 v += r - 1;
327 c = v % r;
328 if(c < 0)
329 c += r;
330 v -= c;
331 return v;
332 }