1 /*
2 * Copyright (C) 2009 Nicolai Haehnle.
3 *
4 * All Rights Reserved.
5 *
6 * Permission is hereby granted, free of charge, to any person obtaining
7 * a copy of this software and associated documentation files (the
8 * "Software"), to deal in the Software without restriction, including
9 * without limitation the rights to use, copy, modify, merge, publish,
10 * distribute, sublicense, and/or sell copies of the Software, and to
11 * permit persons to whom the Software is furnished to do so, subject to
12 * the following conditions:
13 *
14 * The above copyright notice and this permission notice (including the
15 * next paragraph) shall be included in all copies or substantial
16 * portions of the Software.
17 *
18 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
19 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
20 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
21 * IN NO EVENT SHALL THE COPYRIGHT OWNER(S) AND/OR ITS SUPPLIERS BE
22 * LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
23 * OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
24 * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
25 *
26 */
27
28 #include "radeon_dataflow.h"
29
30 #include "radeon_compiler.h"
31
32
33 struct updatemask_state {
34 unsigned char Output[RC_REGISTER_MAX_INDEX];
35 unsigned char Temporary[RC_REGISTER_MAX_INDEX];
36 unsigned char Address;
37 unsigned char Special[RC_NUM_SPECIAL_REGISTERS];
38 };
39
40 struct instruction_state {
41 unsigned char WriteMask:4;
42 unsigned char WriteALUResult:1;
43 unsigned char SrcReg[3];
44 };
45
46 struct loopinfo {
47 struct updatemask_state * Breaks;
48 unsigned int BreakCount;
49 unsigned int BreaksReserved;
50 };
51
52 struct branchinfo {
53 unsigned int HaveElse:1;
54
55 struct updatemask_state StoreEndif;
56 struct updatemask_state StoreElse;
57 };
58
59 struct deadcode_state {
60 struct radeon_compiler * C;
61 struct instruction_state * Instructions;
62
63 struct updatemask_state R;
64
65 struct branchinfo * BranchStack;
66 unsigned int BranchStackSize;
67 unsigned int BranchStackReserved;
68
69 struct loopinfo * LoopStack;
70 unsigned int LoopStackSize;
71 unsigned int LoopStackReserved;
72 };
73
74
or_updatemasks(struct updatemask_state * dst,struct updatemask_state * a,struct updatemask_state * b)75 static void or_updatemasks(
76 struct updatemask_state * dst,
77 struct updatemask_state * a,
78 struct updatemask_state * b)
79 {
80 for(unsigned int i = 0; i < RC_REGISTER_MAX_INDEX; ++i) {
81 dst->Output[i] = a->Output[i] | b->Output[i];
82 dst->Temporary[i] = a->Temporary[i] | b->Temporary[i];
83 }
84
85 for(unsigned int i = 0; i < RC_NUM_SPECIAL_REGISTERS; ++i)
86 dst->Special[i] = a->Special[i] | b->Special[i];
87
88 dst->Address = a->Address | b->Address;
89 }
90
push_break(struct deadcode_state * s)91 static void push_break(struct deadcode_state *s)
92 {
93 struct loopinfo * loop = &s->LoopStack[s->LoopStackSize - 1];
94 memory_pool_array_reserve(&s->C->Pool, struct updatemask_state,
95 loop->Breaks, loop->BreakCount, loop->BreaksReserved, 1);
96
97 memcpy(&loop->Breaks[loop->BreakCount++], &s->R, sizeof(s->R));
98 }
99
push_loop(struct deadcode_state * s)100 static void push_loop(struct deadcode_state * s)
101 {
102 memory_pool_array_reserve(&s->C->Pool, struct loopinfo, s->LoopStack,
103 s->LoopStackSize, s->LoopStackReserved, 1);
104 memset(&s->LoopStack[s->LoopStackSize++], 0, sizeof(struct loopinfo));
105 }
106
push_branch(struct deadcode_state * s)107 static void push_branch(struct deadcode_state * s)
108 {
109 struct branchinfo * branch;
110
111 memory_pool_array_reserve(&s->C->Pool, struct branchinfo, s->BranchStack,
112 s->BranchStackSize, s->BranchStackReserved, 1);
113
114 branch = &s->BranchStack[s->BranchStackSize++];
115 branch->HaveElse = 0;
116 memcpy(&branch->StoreEndif, &s->R, sizeof(s->R));
117 }
118
get_used_ptr(struct deadcode_state * s,rc_register_file file,unsigned int index)119 static unsigned char * get_used_ptr(struct deadcode_state *s, rc_register_file file, unsigned int index)
120 {
121 if (file == RC_FILE_OUTPUT || file == RC_FILE_TEMPORARY) {
122 if (index >= RC_REGISTER_MAX_INDEX) {
123 rc_error(s->C, "%s: index %i is out of bounds for file %i\n", __FUNCTION__, index, file);
124 return 0;
125 }
126
127 if (file == RC_FILE_OUTPUT)
128 return &s->R.Output[index];
129 else
130 return &s->R.Temporary[index];
131 } else if (file == RC_FILE_ADDRESS) {
132 return &s->R.Address;
133 } else if (file == RC_FILE_SPECIAL) {
134 if (index >= RC_NUM_SPECIAL_REGISTERS) {
135 rc_error(s->C, "%s: special file index %i out of bounds\n", __FUNCTION__, index);
136 return 0;
137 }
138
139 return &s->R.Special[index];
140 }
141
142 return 0;
143 }
144
mark_used(struct deadcode_state * s,rc_register_file file,unsigned int index,unsigned int mask)145 static void mark_used(struct deadcode_state * s, rc_register_file file, unsigned int index, unsigned int mask)
146 {
147 unsigned char * pused = get_used_ptr(s, file, index);
148 if (pused)
149 *pused |= mask;
150 }
151
update_instruction(struct deadcode_state * s,struct rc_instruction * inst)152 static void update_instruction(struct deadcode_state * s, struct rc_instruction * inst)
153 {
154 const struct rc_opcode_info * opcode = rc_get_opcode_info(inst->U.I.Opcode);
155 struct instruction_state * insts = &s->Instructions[inst->IP];
156 unsigned int usedmask = 0;
157 unsigned int srcmasks[3];
158
159 if (opcode->HasDstReg) {
160 unsigned char * pused = get_used_ptr(s, inst->U.I.DstReg.File, inst->U.I.DstReg.Index);
161 if (pused) {
162 usedmask = *pused & inst->U.I.DstReg.WriteMask;
163 *pused &= ~usedmask;
164 }
165 }
166
167 insts->WriteMask |= usedmask;
168
169 if (inst->U.I.WriteALUResult) {
170 unsigned char * pused = get_used_ptr(s, RC_FILE_SPECIAL, RC_SPECIAL_ALU_RESULT);
171 if (pused && *pused) {
172 if (inst->U.I.WriteALUResult == RC_ALURESULT_X)
173 usedmask |= RC_MASK_X;
174 else if (inst->U.I.WriteALUResult == RC_ALURESULT_W)
175 usedmask |= RC_MASK_W;
176
177 *pused = 0;
178 insts->WriteALUResult = 1;
179 }
180 }
181
182 rc_compute_sources_for_writemask(inst, usedmask, srcmasks);
183
184 for(unsigned int src = 0; src < opcode->NumSrcRegs; ++src) {
185 unsigned int refmask = 0;
186 unsigned int newsrcmask = srcmasks[src] & ~insts->SrcReg[src];
187 insts->SrcReg[src] |= newsrcmask;
188
189 for(unsigned int chan = 0; chan < 4; ++chan) {
190 if (GET_BIT(newsrcmask, chan))
191 refmask |= 1 << GET_SWZ(inst->U.I.SrcReg[src].Swizzle, chan);
192 }
193
194 /* get rid of spurious bits from ZERO, ONE, etc. swizzles */
195 refmask &= RC_MASK_XYZW;
196
197 if (!refmask)
198 continue;
199
200 mark_used(s, inst->U.I.SrcReg[src].File, inst->U.I.SrcReg[src].Index, refmask);
201
202 if (inst->U.I.SrcReg[src].RelAddr)
203 mark_used(s, RC_FILE_ADDRESS, 0, RC_MASK_X);
204 }
205 }
206
mark_output_use(void * data,unsigned int index,unsigned int mask)207 static void mark_output_use(void * data, unsigned int index, unsigned int mask)
208 {
209 struct deadcode_state * s = data;
210
211 mark_used(s, RC_FILE_OUTPUT, index, mask);
212 }
213
rc_dataflow_deadcode(struct radeon_compiler * c,void * user)214 void rc_dataflow_deadcode(struct radeon_compiler * c, void *user)
215 {
216 struct deadcode_state s;
217 unsigned int nr_instructions;
218 rc_dataflow_mark_outputs_fn dce = (rc_dataflow_mark_outputs_fn)user;
219 unsigned int ip;
220
221 memset(&s, 0, sizeof(s));
222 s.C = c;
223
224 nr_instructions = rc_recompute_ips(c);
225 s.Instructions = memory_pool_malloc(&c->Pool, sizeof(struct instruction_state)*nr_instructions);
226 memset(s.Instructions, 0, sizeof(struct instruction_state)*nr_instructions);
227
228 dce(c, &s, &mark_output_use);
229
230 for(struct rc_instruction * inst = c->Program.Instructions.Prev;
231 inst != &c->Program.Instructions;
232 inst = inst->Prev) {
233 const struct rc_opcode_info * opcode = rc_get_opcode_info(inst->U.I.Opcode);
234
235 switch(opcode->Opcode){
236 /* Mark all sources in the loop body as used before doing
237 * normal deadcode analysis. This is probably not optimal.
238 */
239 case RC_OPCODE_ENDLOOP:
240 {
241 int endloops = 1;
242 struct rc_instruction *ptr;
243 for(ptr = inst->Prev; endloops > 0; ptr = ptr->Prev){
244 opcode = rc_get_opcode_info(ptr->U.I.Opcode);
245 if(ptr->U.I.Opcode == RC_OPCODE_BGNLOOP){
246 endloops--;
247 continue;
248 }
249 if(ptr->U.I.Opcode == RC_OPCODE_ENDLOOP){
250 endloops++;
251 continue;
252 }
253 if(opcode->HasDstReg){
254 int src = 0;
255 unsigned int srcmasks[3];
256 rc_compute_sources_for_writemask(ptr,
257 ptr->U.I.DstReg.WriteMask, srcmasks);
258 for(src=0; src < opcode->NumSrcRegs; src++){
259 mark_used(&s,
260 ptr->U.I.SrcReg[src].File,
261 ptr->U.I.SrcReg[src].Index,
262 srcmasks[src]);
263 }
264 }
265 }
266 push_loop(&s);
267 break;
268 }
269 case RC_OPCODE_BRK:
270 push_break(&s);
271 break;
272 case RC_OPCODE_BGNLOOP:
273 {
274 unsigned int i;
275 struct loopinfo * loop = &s.LoopStack[s.LoopStackSize-1];
276 for(i = 0; i < loop->BreakCount; i++) {
277 or_updatemasks(&s.R, &s.R, &loop->Breaks[i]);
278 }
279 break;
280 }
281 case RC_OPCODE_CONT:
282 break;
283 case RC_OPCODE_ENDIF:
284 push_branch(&s);
285 break;
286 default:
287 if (opcode->IsFlowControl && s.BranchStackSize) {
288 struct branchinfo * branch = &s.BranchStack[s.BranchStackSize-1];
289 if (opcode->Opcode == RC_OPCODE_IF) {
290 or_updatemasks(&s.R,
291 &s.R,
292 branch->HaveElse ? &branch->StoreElse : &branch->StoreEndif);
293
294 s.BranchStackSize--;
295 } else if (opcode->Opcode == RC_OPCODE_ELSE) {
296 if (branch->HaveElse) {
297 rc_error(c, "%s: Multiple ELSE for one IF/ENDIF\n", __FUNCTION__);
298 } else {
299 memcpy(&branch->StoreElse, &s.R, sizeof(s.R));
300 memcpy(&s.R, &branch->StoreEndif, sizeof(s.R));
301 branch->HaveElse = 1;
302 }
303 } else {
304 rc_error(c, "%s: Unhandled control flow instruction %s\n", __FUNCTION__, opcode->Name);
305 }
306 }
307 }
308
309 update_instruction(&s, inst);
310 }
311
312 ip = 0;
313 for(struct rc_instruction * inst = c->Program.Instructions.Next;
314 inst != &c->Program.Instructions;
315 inst = inst->Next, ++ip) {
316 const struct rc_opcode_info * opcode = rc_get_opcode_info(inst->U.I.Opcode);
317 int dead = 1;
318 unsigned int srcmasks[3];
319 unsigned int usemask;
320
321 if (!opcode->HasDstReg) {
322 dead = 0;
323 } else {
324 inst->U.I.DstReg.WriteMask = s.Instructions[ip].WriteMask;
325 if (s.Instructions[ip].WriteMask)
326 dead = 0;
327
328 if (s.Instructions[ip].WriteALUResult)
329 dead = 0;
330 else
331 inst->U.I.WriteALUResult = RC_ALURESULT_NONE;
332 }
333
334 if (dead) {
335 struct rc_instruction * todelete = inst;
336 inst = inst->Prev;
337 rc_remove_instruction(todelete);
338 continue;
339 }
340
341 usemask = s.Instructions[ip].WriteMask;
342
343 if (inst->U.I.WriteALUResult == RC_ALURESULT_X)
344 usemask |= RC_MASK_X;
345 else if (inst->U.I.WriteALUResult == RC_ALURESULT_W)
346 usemask |= RC_MASK_W;
347
348 rc_compute_sources_for_writemask(inst, usemask, srcmasks);
349
350 for(unsigned int src = 0; src < 3; ++src) {
351 for(unsigned int chan = 0; chan < 4; ++chan) {
352 if (!GET_BIT(srcmasks[src], chan))
353 SET_SWZ(inst->U.I.SrcReg[src].Swizzle, chan, RC_SWIZZLE_UNUSED);
354 }
355 }
356 }
357
358 rc_calculate_inputs_outputs(c);
359 }
360