1//
2// Copyright (C) 2014 LunarG, Inc.
3// Copyright (C) 2015-2018 Google, Inc.
4//
5// All rights reserved.
6//
7// Redistribution and use in source and binary forms, with or without
8// modification, are permitted provided that the following conditions
9// are met:
10//
11// Redistributions of source code must retain the above copyright
12// notice, this list of conditions and the following disclaimer.
13//
14// Redistributions in binary form must reproduce the above
15// copyright notice, this list of conditions and the following
16// disclaimer in the documentation and/or other materials provided
17// with the distribution.
18//
19// Neither the name of 3Dlabs Inc. Ltd. nor the names of its
20// contributors may be used to endorse or promote products derived
21// from this software without specific prior written permission.
22//
23// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
24// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
25// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
26// FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
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32// LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
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34// POSSIBILITY OF SUCH DAMAGE.
35
36// SPIRV-IR
37//
38// Simple in-memory representation (IR) of SPIRV. Just for holding
39// Each function's CFG of blocks. Has this hierarchy:
40// - Module, which is a list of
41// - Function, which is a list of
42// - Block, which is a list of
43// - Instruction
44//
45
46#pragma once
47#ifndef spvIR_H
48#define spvIR_H
49
50#include "spirv.hpp"
51
52#include <algorithm>
53#include <cassert>
54#include <functional>
55#include <iostream>
56#include <memory>
57#include <vector>
58#include <set>
59
60namespace spv {
61
62class Block;
63class Function;
64class Module;
65
66const Id NoResult = 0;
67const Id NoType = 0;
68
69const Decoration NoPrecision = DecorationMax;
70
71#ifdef __GNUC__
72# define POTENTIALLY_UNUSED __attribute__((unused))
73#else
74# define POTENTIALLY_UNUSED
75#endif
76
77POTENTIALLY_UNUSED
78const MemorySemanticsMask MemorySemanticsAllMemory =
79 (MemorySemanticsMask)(MemorySemanticsUniformMemoryMask |
80 MemorySemanticsWorkgroupMemoryMask |
81 MemorySemanticsAtomicCounterMemoryMask |
82 MemorySemanticsImageMemoryMask);
83
84struct IdImmediate {
85 bool isId; // true if word is an Id, false if word is an immediate
86 unsigned word;
87 IdImmediate(bool i, unsigned w) : isId(i), word(w) {}
88};
89
90//
91// SPIR-V IR instruction.
92//
93
94class Instruction {
95public:
96 Instruction(Id resultId, Id typeId, Op opCode) : resultId(resultId), typeId(typeId), opCode(opCode), block(nullptr) { }
97 explicit Instruction(Op opCode) : resultId(NoResult), typeId(NoType), opCode(opCode), block(nullptr) { }
98 virtual ~Instruction() {}
99 void addIdOperand(Id id) {
100 operands.push_back(id);
101 idOperand.push_back(true);
102 }
103 void addImmediateOperand(unsigned int immediate) {
104 operands.push_back(immediate);
105 idOperand.push_back(false);
106 }
107 void setImmediateOperand(unsigned idx, unsigned int immediate) {
108 assert(!idOperand[idx]);
109 operands[idx] = immediate;
110 }
111
112 void addStringOperand(const char* str)
113 {
114 unsigned int word = 0;
115 unsigned int shiftAmount = 0;
116 char c;
117
118 do {
119 c = *(str++);
120 word |= ((unsigned int)c) << shiftAmount;
121 shiftAmount += 8;
122 if (shiftAmount == 32) {
123 addImmediateOperand(word);
124 word = 0;
125 shiftAmount = 0;
126 }
127 } while (c != 0);
128
129 // deal with partial last word
130 if (shiftAmount > 0) {
131 addImmediateOperand(word);
132 }
133 }
134 bool isIdOperand(int op) const { return idOperand[op]; }
135 void setBlock(Block* b) { block = b; }
136 Block* getBlock() const { return block; }
137 Op getOpCode() const { return opCode; }
138 int getNumOperands() const
139 {
140 assert(operands.size() == idOperand.size());
141 return (int)operands.size();
142 }
143 Id getResultId() const { return resultId; }
144 Id getTypeId() const { return typeId; }
145 Id getIdOperand(int op) const {
146 assert(idOperand[op]);
147 return operands[op];
148 }
149 unsigned int getImmediateOperand(int op) const {
150 assert(!idOperand[op]);
151 return operands[op];
152 }
153
154 // Write out the binary form.
155 void dump(std::vector<unsigned int>& out) const
156 {
157 // Compute the wordCount
158 unsigned int wordCount = 1;
159 if (typeId)
160 ++wordCount;
161 if (resultId)
162 ++wordCount;
163 wordCount += (unsigned int)operands.size();
164
165 // Write out the beginning of the instruction
166 out.push_back(((wordCount) << WordCountShift) | opCode);
167 if (typeId)
168 out.push_back(typeId);
169 if (resultId)
170 out.push_back(resultId);
171
172 // Write out the operands
173 for (int op = 0; op < (int)operands.size(); ++op)
174 out.push_back(operands[op]);
175 }
176
177protected:
178 Instruction(const Instruction&);
179 Id resultId;
180 Id typeId;
181 Op opCode;
182 std::vector<Id> operands; // operands, both <id> and immediates (both are unsigned int)
183 std::vector<bool> idOperand; // true for operands that are <id>, false for immediates
184 Block* block;
185};
186
187//
188// SPIR-V IR block.
189//
190
191class Block {
192public:
193 Block(Id id, Function& parent);
194 virtual ~Block()
195 {
196 }
197
198 Id getId() { return instructions.front()->getResultId(); }
199
200 Function& getParent() const { return parent; }
201 void addInstruction(std::unique_ptr<Instruction> inst);
202 void addPredecessor(Block* pred) { predecessors.push_back(pred); pred->successors.push_back(this);}
203 void addLocalVariable(std::unique_ptr<Instruction> inst) { localVariables.push_back(std::move(inst)); }
204 const std::vector<Block*>& getPredecessors() const { return predecessors; }
205 const std::vector<Block*>& getSuccessors() const { return successors; }
206 const std::vector<std::unique_ptr<Instruction> >& getInstructions() const {
207 return instructions;
208 }
209 const std::vector<std::unique_ptr<Instruction> >& getLocalVariables() const { return localVariables; }
210 void setUnreachable() { unreachable = true; }
211 bool isUnreachable() const { return unreachable; }
212 // Returns the block's merge instruction, if one exists (otherwise null).
213 const Instruction* getMergeInstruction() const {
214 if (instructions.size() < 2) return nullptr;
215 const Instruction* nextToLast = (instructions.cend() - 2)->get();
216 switch (nextToLast->getOpCode()) {
217 case OpSelectionMerge:
218 case OpLoopMerge:
219 return nextToLast;
220 default:
221 return nullptr;
222 }
223 return nullptr;
224 }
225
226 // Change this block into a canonical dead merge block. Delete instructions
227 // as necessary. A canonical dead merge block has only an OpLabel and an
228 // OpUnreachable.
229 void rewriteAsCanonicalUnreachableMerge() {
230 assert(localVariables.empty());
231 // Delete all instructions except for the label.
232 assert(instructions.size() > 0);
233 instructions.resize(1);
234 successors.clear();
235 addInstruction(std::unique_ptr<Instruction>(new Instruction(OpUnreachable)));
236 }
237 // Change this block into a canonical dead continue target branching to the
238 // given header ID. Delete instructions as necessary. A canonical dead continue
239 // target has only an OpLabel and an unconditional branch back to the corresponding
240 // header.
241 void rewriteAsCanonicalUnreachableContinue(Block* header) {
242 assert(localVariables.empty());
243 // Delete all instructions except for the label.
244 assert(instructions.size() > 0);
245 instructions.resize(1);
246 successors.clear();
247 // Add OpBranch back to the header.
248 assert(header != nullptr);
249 Instruction* branch = new Instruction(OpBranch);
250 branch->addIdOperand(header->getId());
251 addInstruction(std::unique_ptr<Instruction>(branch));
252 successors.push_back(header);
253 }
254
255 bool isTerminated() const
256 {
257 switch (instructions.back()->getOpCode()) {
258 case OpBranch:
259 case OpBranchConditional:
260 case OpSwitch:
261 case OpKill:
262 case OpTerminateInvocation:
263 case OpReturn:
264 case OpReturnValue:
265 case OpUnreachable:
266 return true;
267 default:
268 return false;
269 }
270 }
271
272 void dump(std::vector<unsigned int>& out) const
273 {
274 instructions[0]->dump(out);
275 for (int i = 0; i < (int)localVariables.size(); ++i)
276 localVariables[i]->dump(out);
277 for (int i = 1; i < (int)instructions.size(); ++i)
278 instructions[i]->dump(out);
279 }
280
281protected:
282 Block(const Block&);
283 Block& operator=(Block&);
284
285 // To enforce keeping parent and ownership in sync:
286 friend Function;
287
288 std::vector<std::unique_ptr<Instruction> > instructions;
289 std::vector<Block*> predecessors, successors;
290 std::vector<std::unique_ptr<Instruction> > localVariables;
291 Function& parent;
292
293 // track whether this block is known to be uncreachable (not necessarily
294 // true for all unreachable blocks, but should be set at least
295 // for the extraneous ones introduced by the builder).
296 bool unreachable;
297};
298
299// The different reasons for reaching a block in the inReadableOrder traversal.
300enum ReachReason {
301 // Reachable from the entry block via transfers of control, i.e. branches.
302 ReachViaControlFlow = 0,
303 // A continue target that is not reachable via control flow.
304 ReachDeadContinue,
305 // A merge block that is not reachable via control flow.
306 ReachDeadMerge
307};
308
309// Traverses the control-flow graph rooted at root in an order suited for
310// readable code generation. Invokes callback at every node in the traversal
311// order. The callback arguments are:
312// - the block,
313// - the reason we reached the block,
314// - if the reason was that block is an unreachable continue or unreachable merge block
315// then the last parameter is the corresponding header block.
316void inReadableOrder(Block* root, std::function<void(Block*, ReachReason, Block* header)> callback);
317
318//
319// SPIR-V IR Function.
320//
321
322class Function {
323public:
324 Function(Id id, Id resultType, Id functionType, Id firstParam, Module& parent);
325 virtual ~Function()
326 {
327 for (int i = 0; i < (int)parameterInstructions.size(); ++i)
328 delete parameterInstructions[i];
329
330 for (int i = 0; i < (int)blocks.size(); ++i)
331 delete blocks[i];
332 }
333 Id getId() const { return functionInstruction.getResultId(); }
334 Id getParamId(int p) const { return parameterInstructions[p]->getResultId(); }
335 Id getParamType(int p) const { return parameterInstructions[p]->getTypeId(); }
336
337 void addBlock(Block* block) { blocks.push_back(block); }
338 void removeBlock(Block* block)
339 {
340 auto found = find(blocks.begin(), blocks.end(), block);
341 assert(found != blocks.end());
342 blocks.erase(found);
343 delete block;
344 }
345
346 Module& getParent() const { return parent; }
347 Block* getEntryBlock() const { return blocks.front(); }
348 Block* getLastBlock() const { return blocks.back(); }
349 const std::vector<Block*>& getBlocks() const { return blocks; }
350 void addLocalVariable(std::unique_ptr<Instruction> inst);
351 Id getReturnType() const { return functionInstruction.getTypeId(); }
352 Id getFuncId() const { return functionInstruction.getResultId(); }
353 void setReturnPrecision(Decoration precision)
354 {
355 if (precision == DecorationRelaxedPrecision)
356 reducedPrecisionReturn = true;
357 }
358 Decoration getReturnPrecision() const
359 { return reducedPrecisionReturn ? DecorationRelaxedPrecision : NoPrecision; }
360
361 void setDebugLineInfo(Id fileName, int line, int column) {
362 lineInstruction = std::unique_ptr<Instruction>{new Instruction(OpLine)};
363 lineInstruction->addIdOperand(fileName);
364 lineInstruction->addImmediateOperand(line);
365 lineInstruction->addImmediateOperand(column);
366 }
367 bool hasDebugLineInfo() const { return lineInstruction != nullptr; }
368
369 void setImplicitThis() { implicitThis = true; }
370 bool hasImplicitThis() const { return implicitThis; }
371
372 void addParamPrecision(unsigned param, Decoration precision)
373 {
374 if (precision == DecorationRelaxedPrecision)
375 reducedPrecisionParams.insert(param);
376 }
377 Decoration getParamPrecision(unsigned param) const
378 {
379 return reducedPrecisionParams.find(param) != reducedPrecisionParams.end() ?
380 DecorationRelaxedPrecision : NoPrecision;
381 }
382
383 void dump(std::vector<unsigned int>& out) const
384 {
385 // OpLine
386 if (lineInstruction != nullptr) {
387 lineInstruction->dump(out);
388 }
389
390 // OpFunction
391 functionInstruction.dump(out);
392
393 // OpFunctionParameter
394 for (int p = 0; p < (int)parameterInstructions.size(); ++p)
395 parameterInstructions[p]->dump(out);
396
397 // Blocks
398 inReadableOrder(blocks[0], [&out](const Block* b, ReachReason, Block*) { b->dump(out); });
399 Instruction end(0, 0, OpFunctionEnd);
400 end.dump(out);
401 }
402
403protected:
404 Function(const Function&);
405 Function& operator=(Function&);
406
407 Module& parent;
408 std::unique_ptr<Instruction> lineInstruction;
409 Instruction functionInstruction;
410 std::vector<Instruction*> parameterInstructions;
411 std::vector<Block*> blocks;
412 bool implicitThis; // true if this is a member function expecting to be passed a 'this' as the first argument
413 bool reducedPrecisionReturn;
414 std::set<int> reducedPrecisionParams; // list of parameter indexes that need a relaxed precision arg
415};
416
417//
418// SPIR-V IR Module.
419//
420
421class Module {
422public:
423 Module() {}
424 virtual ~Module()
425 {
426 // TODO delete things
427 }
428
429 void addFunction(Function *fun) { functions.push_back(fun); }
430
431 void mapInstruction(Instruction *instruction)
432 {
433 spv::Id resultId = instruction->getResultId();
434 // map the instruction's result id
435 if (resultId >= idToInstruction.size())
436 idToInstruction.resize(resultId + 16);
437 idToInstruction[resultId] = instruction;
438 }
439
440 Instruction* getInstruction(Id id) const { return idToInstruction[id]; }
441 const std::vector<Function*>& getFunctions() const { return functions; }
442 spv::Id getTypeId(Id resultId) const {
443 return idToInstruction[resultId] == nullptr ? NoType : idToInstruction[resultId]->getTypeId();
444 }
445 StorageClass getStorageClass(Id typeId) const
446 {
447 assert(idToInstruction[typeId]->getOpCode() == spv::OpTypePointer);
448 return (StorageClass)idToInstruction[typeId]->getImmediateOperand(0);
449 }
450
451 void dump(std::vector<unsigned int>& out) const
452 {
453 for (int f = 0; f < (int)functions.size(); ++f)
454 functions[f]->dump(out);
455 }
456
457protected:
458 Module(const Module&);
459 std::vector<Function*> functions;
460
461 // map from result id to instruction having that result id
462 std::vector<Instruction*> idToInstruction;
463
464 // map from a result id to its type id
465};
466
467//
468// Implementation (it's here due to circular type definitions).
469//
470
471// Add both
472// - the OpFunction instruction
473// - all the OpFunctionParameter instructions
474__inline Function::Function(Id id, Id resultType, Id functionType, Id firstParamId, Module& parent)
475 : parent(parent), lineInstruction(nullptr),
476 functionInstruction(id, resultType, OpFunction), implicitThis(false),
477 reducedPrecisionReturn(false)
478{
479 // OpFunction
480 functionInstruction.addImmediateOperand(FunctionControlMaskNone);
481 functionInstruction.addIdOperand(functionType);
482 parent.mapInstruction(&functionInstruction);
483 parent.addFunction(this);
484
485 // OpFunctionParameter
486 Instruction* typeInst = parent.getInstruction(functionType);
487 int numParams = typeInst->getNumOperands() - 1;
488 for (int p = 0; p < numParams; ++p) {
489 Instruction* param = new Instruction(firstParamId + p, typeInst->getIdOperand(p + 1), OpFunctionParameter);
490 parent.mapInstruction(param);
491 parameterInstructions.push_back(param);
492 }
493}
494
495__inline void Function::addLocalVariable(std::unique_ptr<Instruction> inst)
496{
497 Instruction* raw_instruction = inst.get();
498 blocks[0]->addLocalVariable(std::move(inst));
499 parent.mapInstruction(raw_instruction);
500}
501
502__inline Block::Block(Id id, Function& parent) : parent(parent), unreachable(false)
503{
504 instructions.push_back(std::unique_ptr<Instruction>(new Instruction(id, NoType, OpLabel)));
505 instructions.back()->setBlock(this);
506 parent.getParent().mapInstruction(instructions.back().get());
507}
508
509__inline void Block::addInstruction(std::unique_ptr<Instruction> inst)
510{
511 Instruction* raw_instruction = inst.get();
512 instructions.push_back(std::move(inst));
513 raw_instruction->setBlock(this);
514 if (raw_instruction->getResultId())
515 parent.getParent().mapInstruction(raw_instruction);
516}
517
518} // end spv namespace
519
520#endif // spvIR_H
521