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
27 // COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
28 // INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
29 // BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
30 // LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
31 // CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
32 // LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
33 // ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
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
60 namespace spv {
61
62 class Block;
63 class Function;
64 class Module;
65
66 const Id NoResult = 0;
67 const Id NoType = 0;
68
69 const Decoration NoPrecision = DecorationMax;
70
71 #ifdef __GNUC__
72 # define POTENTIALLY_UNUSED __attribute__((unused))
73 #else
74 # define POTENTIALLY_UNUSED
75 #endif
76
77 POTENTIALLY_UNUSED
78 const MemorySemanticsMask MemorySemanticsAllMemory =
79 (MemorySemanticsMask)(MemorySemanticsUniformMemoryMask |
80 MemorySemanticsWorkgroupMemoryMask |
81 MemorySemanticsAtomicCounterMemoryMask |
82 MemorySemanticsImageMemoryMask);
83
84 struct IdImmediate {
85 bool isId; // true if word is an Id, false if word is an immediate
86 unsigned word;
IdImmediateIdImmediate87 IdImmediate(bool i, unsigned w) : isId(i), word(w) {}
88 };
89
90 //
91 // SPIR-V IR instruction.
92 //
93
94 class Instruction {
95 public:
Instruction(Id resultId,Id typeId,Op opCode)96 Instruction(Id resultId, Id typeId, Op opCode) : resultId(resultId), typeId(typeId), opCode(opCode), block(nullptr) { }
Instruction(Op opCode)97 explicit Instruction(Op opCode) : resultId(NoResult), typeId(NoType), opCode(opCode), block(nullptr) { }
~Instruction()98 virtual ~Instruction() {}
addIdOperand(Id id)99 void addIdOperand(Id id) {
100 // ids can't be 0
101 assert(id);
102 operands.push_back(id);
103 idOperand.push_back(true);
104 }
addImmediateOperand(unsigned int immediate)105 void addImmediateOperand(unsigned int immediate) {
106 operands.push_back(immediate);
107 idOperand.push_back(false);
108 }
setImmediateOperand(unsigned idx,unsigned int immediate)109 void setImmediateOperand(unsigned idx, unsigned int immediate) {
110 assert(!idOperand[idx]);
111 operands[idx] = immediate;
112 }
113
addStringOperand(const char * str)114 void addStringOperand(const char* str)
115 {
116 unsigned int word = 0;
117 unsigned int shiftAmount = 0;
118 char c;
119
120 do {
121 c = *(str++);
122 word |= ((unsigned int)c) << shiftAmount;
123 shiftAmount += 8;
124 if (shiftAmount == 32) {
125 addImmediateOperand(word);
126 word = 0;
127 shiftAmount = 0;
128 }
129 } while (c != 0);
130
131 // deal with partial last word
132 if (shiftAmount > 0) {
133 addImmediateOperand(word);
134 }
135 }
isIdOperand(int op)136 bool isIdOperand(int op) const { return idOperand[op]; }
setBlock(Block * b)137 void setBlock(Block* b) { block = b; }
getBlock()138 Block* getBlock() const { return block; }
getOpCode()139 Op getOpCode() const { return opCode; }
getNumOperands()140 int getNumOperands() const
141 {
142 assert(operands.size() == idOperand.size());
143 return (int)operands.size();
144 }
getResultId()145 Id getResultId() const { return resultId; }
getTypeId()146 Id getTypeId() const { return typeId; }
getIdOperand(int op)147 Id getIdOperand(int op) const {
148 assert(idOperand[op]);
149 return operands[op];
150 }
getImmediateOperand(int op)151 unsigned int getImmediateOperand(int op) const {
152 assert(!idOperand[op]);
153 return operands[op];
154 }
155
156 // Write out the binary form.
dump(std::vector<unsigned int> & out)157 void dump(std::vector<unsigned int>& out) const
158 {
159 // Compute the wordCount
160 unsigned int wordCount = 1;
161 if (typeId)
162 ++wordCount;
163 if (resultId)
164 ++wordCount;
165 wordCount += (unsigned int)operands.size();
166
167 // Write out the beginning of the instruction
168 out.push_back(((wordCount) << WordCountShift) | opCode);
169 if (typeId)
170 out.push_back(typeId);
171 if (resultId)
172 out.push_back(resultId);
173
174 // Write out the operands
175 for (int op = 0; op < (int)operands.size(); ++op)
176 out.push_back(operands[op]);
177 }
178
179 protected:
180 Instruction(const Instruction&);
181 Id resultId;
182 Id typeId;
183 Op opCode;
184 std::vector<Id> operands; // operands, both <id> and immediates (both are unsigned int)
185 std::vector<bool> idOperand; // true for operands that are <id>, false for immediates
186 Block* block;
187 };
188
189 //
190 // SPIR-V IR block.
191 //
192
193 class Block {
194 public:
195 Block(Id id, Function& parent);
~Block()196 virtual ~Block()
197 {
198 }
199
getId()200 Id getId() { return instructions.front()->getResultId(); }
201
getParent()202 Function& getParent() const { return parent; }
203 void addInstruction(std::unique_ptr<Instruction> inst);
addPredecessor(Block * pred)204 void addPredecessor(Block* pred) { predecessors.push_back(pred); pred->successors.push_back(this);}
addLocalVariable(std::unique_ptr<Instruction> inst)205 void addLocalVariable(std::unique_ptr<Instruction> inst) { localVariables.push_back(std::move(inst)); }
getPredecessors()206 const std::vector<Block*>& getPredecessors() const { return predecessors; }
getSuccessors()207 const std::vector<Block*>& getSuccessors() const { return successors; }
getInstructions()208 const std::vector<std::unique_ptr<Instruction> >& getInstructions() const {
209 return instructions;
210 }
getLocalVariables()211 const std::vector<std::unique_ptr<Instruction> >& getLocalVariables() const { return localVariables; }
setUnreachable()212 void setUnreachable() { unreachable = true; }
isUnreachable()213 bool isUnreachable() const { return unreachable; }
214 // Returns the block's merge instruction, if one exists (otherwise null).
getMergeInstruction()215 const Instruction* getMergeInstruction() const {
216 if (instructions.size() < 2) return nullptr;
217 const Instruction* nextToLast = (instructions.cend() - 2)->get();
218 switch (nextToLast->getOpCode()) {
219 case OpSelectionMerge:
220 case OpLoopMerge:
221 return nextToLast;
222 default:
223 return nullptr;
224 }
225 return nullptr;
226 }
227
228 // Change this block into a canonical dead merge block. Delete instructions
229 // as necessary. A canonical dead merge block has only an OpLabel and an
230 // OpUnreachable.
rewriteAsCanonicalUnreachableMerge()231 void rewriteAsCanonicalUnreachableMerge() {
232 assert(localVariables.empty());
233 // Delete all instructions except for the label.
234 assert(instructions.size() > 0);
235 instructions.resize(1);
236 successors.clear();
237 addInstruction(std::unique_ptr<Instruction>(new Instruction(OpUnreachable)));
238 }
239 // Change this block into a canonical dead continue target branching to the
240 // given header ID. Delete instructions as necessary. A canonical dead continue
241 // target has only an OpLabel and an unconditional branch back to the corresponding
242 // header.
rewriteAsCanonicalUnreachableContinue(Block * header)243 void rewriteAsCanonicalUnreachableContinue(Block* header) {
244 assert(localVariables.empty());
245 // Delete all instructions except for the label.
246 assert(instructions.size() > 0);
247 instructions.resize(1);
248 successors.clear();
249 // Add OpBranch back to the header.
250 assert(header != nullptr);
251 Instruction* branch = new Instruction(OpBranch);
252 branch->addIdOperand(header->getId());
253 addInstruction(std::unique_ptr<Instruction>(branch));
254 successors.push_back(header);
255 }
256
isTerminated()257 bool isTerminated() const
258 {
259 switch (instructions.back()->getOpCode()) {
260 case OpBranch:
261 case OpBranchConditional:
262 case OpSwitch:
263 case OpKill:
264 case OpTerminateInvocation:
265 case OpReturn:
266 case OpReturnValue:
267 case OpUnreachable:
268 return true;
269 default:
270 return false;
271 }
272 }
273
dump(std::vector<unsigned int> & out)274 void dump(std::vector<unsigned int>& out) const
275 {
276 instructions[0]->dump(out);
277 for (int i = 0; i < (int)localVariables.size(); ++i)
278 localVariables[i]->dump(out);
279 for (int i = 1; i < (int)instructions.size(); ++i)
280 instructions[i]->dump(out);
281 }
282
283 protected:
284 Block(const Block&);
285 Block& operator=(Block&);
286
287 // To enforce keeping parent and ownership in sync:
288 friend Function;
289
290 std::vector<std::unique_ptr<Instruction> > instructions;
291 std::vector<Block*> predecessors, successors;
292 std::vector<std::unique_ptr<Instruction> > localVariables;
293 Function& parent;
294
295 // track whether this block is known to be uncreachable (not necessarily
296 // true for all unreachable blocks, but should be set at least
297 // for the extraneous ones introduced by the builder).
298 bool unreachable;
299 };
300
301 // The different reasons for reaching a block in the inReadableOrder traversal.
302 enum ReachReason {
303 // Reachable from the entry block via transfers of control, i.e. branches.
304 ReachViaControlFlow = 0,
305 // A continue target that is not reachable via control flow.
306 ReachDeadContinue,
307 // A merge block that is not reachable via control flow.
308 ReachDeadMerge
309 };
310
311 // Traverses the control-flow graph rooted at root in an order suited for
312 // readable code generation. Invokes callback at every node in the traversal
313 // order. The callback arguments are:
314 // - the block,
315 // - the reason we reached the block,
316 // - if the reason was that block is an unreachable continue or unreachable merge block
317 // then the last parameter is the corresponding header block.
318 void inReadableOrder(Block* root, std::function<void(Block*, ReachReason, Block* header)> callback);
319
320 //
321 // SPIR-V IR Function.
322 //
323
324 class Function {
325 public:
326 Function(Id id, Id resultType, Id functionType, Id firstParam, LinkageType linkage, const std::string& name, Module& parent);
~Function()327 virtual ~Function()
328 {
329 for (int i = 0; i < (int)parameterInstructions.size(); ++i)
330 delete parameterInstructions[i];
331
332 for (int i = 0; i < (int)blocks.size(); ++i)
333 delete blocks[i];
334 }
getId()335 Id getId() const { return functionInstruction.getResultId(); }
getParamId(int p)336 Id getParamId(int p) const { return parameterInstructions[p]->getResultId(); }
getParamType(int p)337 Id getParamType(int p) const { return parameterInstructions[p]->getTypeId(); }
338
addBlock(Block * block)339 void addBlock(Block* block) { blocks.push_back(block); }
removeBlock(Block * block)340 void removeBlock(Block* block)
341 {
342 auto found = find(blocks.begin(), blocks.end(), block);
343 assert(found != blocks.end());
344 blocks.erase(found);
345 delete block;
346 }
347
getParent()348 Module& getParent() const { return parent; }
getEntryBlock()349 Block* getEntryBlock() const { return blocks.front(); }
getLastBlock()350 Block* getLastBlock() const { return blocks.back(); }
getBlocks()351 const std::vector<Block*>& getBlocks() const { return blocks; }
352 void addLocalVariable(std::unique_ptr<Instruction> inst);
getReturnType()353 Id getReturnType() const { return functionInstruction.getTypeId(); }
getFuncId()354 Id getFuncId() const { return functionInstruction.getResultId(); }
getFuncTypeId()355 Id getFuncTypeId() const { return functionInstruction.getIdOperand(1); }
setReturnPrecision(Decoration precision)356 void setReturnPrecision(Decoration precision)
357 {
358 if (precision == DecorationRelaxedPrecision)
359 reducedPrecisionReturn = true;
360 }
getReturnPrecision()361 Decoration getReturnPrecision() const
362 { return reducedPrecisionReturn ? DecorationRelaxedPrecision : NoPrecision; }
363
setDebugLineInfo(Id fileName,int line,int column)364 void setDebugLineInfo(Id fileName, int line, int column) {
365 lineInstruction = std::unique_ptr<Instruction>{new Instruction(OpLine)};
366 lineInstruction->addIdOperand(fileName);
367 lineInstruction->addImmediateOperand(line);
368 lineInstruction->addImmediateOperand(column);
369 }
hasDebugLineInfo()370 bool hasDebugLineInfo() const { return lineInstruction != nullptr; }
371
setImplicitThis()372 void setImplicitThis() { implicitThis = true; }
hasImplicitThis()373 bool hasImplicitThis() const { return implicitThis; }
374
addParamPrecision(unsigned param,Decoration precision)375 void addParamPrecision(unsigned param, Decoration precision)
376 {
377 if (precision == DecorationRelaxedPrecision)
378 reducedPrecisionParams.insert(param);
379 }
getParamPrecision(unsigned param)380 Decoration getParamPrecision(unsigned param) const
381 {
382 return reducedPrecisionParams.find(param) != reducedPrecisionParams.end() ?
383 DecorationRelaxedPrecision : NoPrecision;
384 }
385
dump(std::vector<unsigned int> & out)386 void dump(std::vector<unsigned int>& out) const
387 {
388 // OpLine
389 if (lineInstruction != nullptr) {
390 lineInstruction->dump(out);
391 }
392
393 // OpFunction
394 functionInstruction.dump(out);
395
396 // OpFunctionParameter
397 for (int p = 0; p < (int)parameterInstructions.size(); ++p)
398 parameterInstructions[p]->dump(out);
399
400 // Blocks
401 inReadableOrder(blocks[0], [&out](const Block* b, ReachReason, Block*) { b->dump(out); });
402 Instruction end(0, 0, OpFunctionEnd);
403 end.dump(out);
404 }
405
getLinkType()406 LinkageType getLinkType() const { return linkType; }
getExportName()407 const char* getExportName() const { return exportName.c_str(); }
408
409 protected:
410 Function(const Function&);
411 Function& operator=(Function&);
412
413 Module& parent;
414 std::unique_ptr<Instruction> lineInstruction;
415 Instruction functionInstruction;
416 std::vector<Instruction*> parameterInstructions;
417 std::vector<Block*> blocks;
418 bool implicitThis; // true if this is a member function expecting to be passed a 'this' as the first argument
419 bool reducedPrecisionReturn;
420 std::set<int> reducedPrecisionParams; // list of parameter indexes that need a relaxed precision arg
421 LinkageType linkType;
422 std::string exportName;
423 };
424
425 //
426 // SPIR-V IR Module.
427 //
428
429 class Module {
430 public:
Module()431 Module() {}
~Module()432 virtual ~Module()
433 {
434 // TODO delete things
435 }
436
addFunction(Function * fun)437 void addFunction(Function *fun) { functions.push_back(fun); }
438
mapInstruction(Instruction * instruction)439 void mapInstruction(Instruction *instruction)
440 {
441 spv::Id resultId = instruction->getResultId();
442 // map the instruction's result id
443 if (resultId >= idToInstruction.size())
444 idToInstruction.resize(resultId + 16);
445 idToInstruction[resultId] = instruction;
446 }
447
getInstruction(Id id)448 Instruction* getInstruction(Id id) const { return idToInstruction[id]; }
getFunctions()449 const std::vector<Function*>& getFunctions() const { return functions; }
getTypeId(Id resultId)450 spv::Id getTypeId(Id resultId) const {
451 return idToInstruction[resultId] == nullptr ? NoType : idToInstruction[resultId]->getTypeId();
452 }
getStorageClass(Id typeId)453 StorageClass getStorageClass(Id typeId) const
454 {
455 assert(idToInstruction[typeId]->getOpCode() == spv::OpTypePointer);
456 return (StorageClass)idToInstruction[typeId]->getImmediateOperand(0);
457 }
458
dump(std::vector<unsigned int> & out)459 void dump(std::vector<unsigned int>& out) const
460 {
461 for (int f = 0; f < (int)functions.size(); ++f)
462 functions[f]->dump(out);
463 }
464
465 protected:
466 Module(const Module&);
467 std::vector<Function*> functions;
468
469 // map from result id to instruction having that result id
470 std::vector<Instruction*> idToInstruction;
471
472 // map from a result id to its type id
473 };
474
475 //
476 // Implementation (it's here due to circular type definitions).
477 //
478
479 // Add both
480 // - the OpFunction instruction
481 // - all the OpFunctionParameter instructions
Function(Id id,Id resultType,Id functionType,Id firstParamId,LinkageType linkage,const std::string & name,Module & parent)482 __inline Function::Function(Id id, Id resultType, Id functionType, Id firstParamId, LinkageType linkage, const std::string& name, Module& parent)
483 : parent(parent), lineInstruction(nullptr),
484 functionInstruction(id, resultType, OpFunction), implicitThis(false),
485 reducedPrecisionReturn(false),
486 linkType(linkage)
487 {
488 // OpFunction
489 functionInstruction.addImmediateOperand(FunctionControlMaskNone);
490 functionInstruction.addIdOperand(functionType);
491 parent.mapInstruction(&functionInstruction);
492 parent.addFunction(this);
493
494 // OpFunctionParameter
495 Instruction* typeInst = parent.getInstruction(functionType);
496 int numParams = typeInst->getNumOperands() - 1;
497 for (int p = 0; p < numParams; ++p) {
498 Instruction* param = new Instruction(firstParamId + p, typeInst->getIdOperand(p + 1), OpFunctionParameter);
499 parent.mapInstruction(param);
500 parameterInstructions.push_back(param);
501 }
502
503 // If importing/exporting, save the function name (without the mangled parameters) for the linkage decoration
504 if (linkType != LinkageTypeMax) {
505 exportName = name.substr(0, name.find_first_of('('));
506 }
507 }
508
addLocalVariable(std::unique_ptr<Instruction> inst)509 __inline void Function::addLocalVariable(std::unique_ptr<Instruction> inst)
510 {
511 Instruction* raw_instruction = inst.get();
512 blocks[0]->addLocalVariable(std::move(inst));
513 parent.mapInstruction(raw_instruction);
514 }
515
Block(Id id,Function & parent)516 __inline Block::Block(Id id, Function& parent) : parent(parent), unreachable(false)
517 {
518 instructions.push_back(std::unique_ptr<Instruction>(new Instruction(id, NoType, OpLabel)));
519 instructions.back()->setBlock(this);
520 parent.getParent().mapInstruction(instructions.back().get());
521 }
522
addInstruction(std::unique_ptr<Instruction> inst)523 __inline void Block::addInstruction(std::unique_ptr<Instruction> inst)
524 {
525 Instruction* raw_instruction = inst.get();
526 instructions.push_back(std::move(inst));
527 raw_instruction->setBlock(this);
528 if (raw_instruction->getResultId())
529 parent.getParent().mapInstruction(raw_instruction);
530 }
531
532 } // end spv namespace
533
534 #endif // spvIR_H
535