1 // Copyright (c) 2016 Google Inc. 2 // 3 // Licensed under the Apache License, Version 2.0 (the "License"); 4 // you may not use this file except in compliance with the License. 5 // You may obtain a copy of the License at 6 // 7 // http://www.apache.org/licenses/LICENSE-2.0 8 // 9 // Unless required by applicable law or agreed to in writing, software 10 // distributed under the License is distributed on an "AS IS" BASIS, 11 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 12 // See the License for the specific language governing permissions and 13 // limitations under the License. 14 15 #ifndef INCLUDE_SPIRV_TOOLS_OPTIMIZER_HPP_ 16 #define INCLUDE_SPIRV_TOOLS_OPTIMIZER_HPP_ 17 18 #include <memory> 19 #include <ostream> 20 #include <string> 21 #include <unordered_map> 22 #include <vector> 23 24 #include "libspirv.hpp" 25 26 namespace spvtools { 27 28 namespace opt { 29 class Pass; 30 } 31 32 // C++ interface for SPIR-V optimization functionalities. It wraps the context 33 // (including target environment and the corresponding SPIR-V grammar) and 34 // provides methods for registering optimization passes and optimizing. 35 // 36 // Instances of this class provides basic thread-safety guarantee. 37 class Optimizer { 38 public: 39 // The token for an optimization pass. It is returned via one of the 40 // Create*Pass() standalone functions at the end of this header file and 41 // consumed by the RegisterPass() method. Tokens are one-time objects that 42 // only support move; copying is not allowed. 43 struct PassToken { 44 struct Impl; // Opaque struct for holding inernal data. 45 46 PassToken(std::unique_ptr<Impl>); 47 48 // Tokens for built-in passes should be created using Create*Pass functions 49 // below; for out-of-tree passes, use this constructor instead. 50 // Note that this API isn't guaranteed to be stable and may change without 51 // preserving source or binary compatibility in the future. 52 PassToken(std::unique_ptr<opt::Pass>&& pass); 53 54 // Tokens can only be moved. Copying is disabled. 55 PassToken(const PassToken&) = delete; 56 PassToken(PassToken&&); 57 PassToken& operator=(const PassToken&) = delete; 58 PassToken& operator=(PassToken&&); 59 60 ~PassToken(); 61 62 std::unique_ptr<Impl> impl_; // Unique pointer to internal data. 63 }; 64 65 // Constructs an instance with the given target |env|, which is used to decode 66 // the binaries to be optimized later. 67 // 68 // The instance will have an empty message consumer, which ignores all 69 // messages from the library. Use SetMessageConsumer() to supply a consumer 70 // if messages are of concern. 71 // 72 // For collections of passes that are meant to transform the input into 73 // another execution environment, then the source environment should be 74 // supplied. e.g. for VulkanToWebGPUPasses the environment should be 75 // SPV_ENV_VULKAN_1_1 not SPV_ENV_WEBGPU_0. 76 explicit Optimizer(spv_target_env env); 77 78 // Disables copy/move constructor/assignment operations. 79 Optimizer(const Optimizer&) = delete; 80 Optimizer(Optimizer&&) = delete; 81 Optimizer& operator=(const Optimizer&) = delete; 82 Optimizer& operator=(Optimizer&&) = delete; 83 84 // Destructs this instance. 85 ~Optimizer(); 86 87 // Sets the message consumer to the given |consumer|. The |consumer| will be 88 // invoked once for each message communicated from the library. 89 void SetMessageConsumer(MessageConsumer consumer); 90 91 // Returns a reference to the registered message consumer. 92 const MessageConsumer& consumer() const; 93 94 // Registers the given |pass| to this optimizer. Passes will be run in the 95 // exact order of registration. The token passed in will be consumed by this 96 // method. 97 Optimizer& RegisterPass(PassToken&& pass); 98 99 // Registers passes that attempt to improve performance of generated code. 100 // This sequence of passes is subject to constant review and will change 101 // from time to time. 102 Optimizer& RegisterPerformancePasses(); 103 104 // Registers passes that attempt to improve the size of generated code. 105 // This sequence of passes is subject to constant review and will change 106 // from time to time. 107 Optimizer& RegisterSizePasses(); 108 109 // Registers passes that have been prescribed for converting from Vulkan to 110 // WebGPU. This sequence of passes is subject to constant review and will 111 // change from time to time. 112 Optimizer& RegisterVulkanToWebGPUPasses(); 113 114 // Registers passes that have been prescribed for converting from WebGPU to 115 // Vulkan. This sequence of passes is subject to constant review and will 116 // change from time to time. 117 Optimizer& RegisterWebGPUToVulkanPasses(); 118 119 // Registers passes that attempt to legalize the generated code. 120 // 121 // Note: this recipe is specially designed for legalizing SPIR-V. It should be 122 // used by compilers after translating HLSL source code literally. It should 123 // *not* be used by general workloads for performance or size improvement. 124 // 125 // This sequence of passes is subject to constant review and will change 126 // from time to time. 127 Optimizer& RegisterLegalizationPasses(); 128 129 // Register passes specified in the list of |flags|. Each flag must be a 130 // string of a form accepted by Optimizer::FlagHasValidForm(). 131 // 132 // If the list of flags contains an invalid entry, it returns false and an 133 // error message is emitted to the MessageConsumer object (use 134 // Optimizer::SetMessageConsumer to define a message consumer, if needed). 135 // 136 // If all the passes are registered successfully, it returns true. 137 bool RegisterPassesFromFlags(const std::vector<std::string>& flags); 138 139 // Registers the optimization pass associated with |flag|. This only accepts 140 // |flag| values of the form "--pass_name[=pass_args]". If no such pass 141 // exists, it returns false. Otherwise, the pass is registered and it returns 142 // true. 143 // 144 // The following flags have special meaning: 145 // 146 // -O: Registers all performance optimization passes 147 // (Optimizer::RegisterPerformancePasses) 148 // 149 // -Os: Registers all size optimization passes 150 // (Optimizer::RegisterSizePasses). 151 // 152 // --legalize-hlsl: Registers all passes that legalize SPIR-V generated by an 153 // HLSL front-end. 154 bool RegisterPassFromFlag(const std::string& flag); 155 156 // Validates that |flag| has a valid format. Strings accepted: 157 // 158 // --pass_name[=pass_args] 159 // -O 160 // -Os 161 // 162 // If |flag| takes one of the forms above, it returns true. Otherwise, it 163 // returns false. 164 bool FlagHasValidForm(const std::string& flag) const; 165 166 // Allows changing, after creation time, the target environment to be 167 // optimized for and validated. Should be called before calling Run(). 168 void SetTargetEnv(const spv_target_env env); 169 170 // Optimizes the given SPIR-V module |original_binary| and writes the 171 // optimized binary into |optimized_binary|. The optimized binary uses 172 // the same SPIR-V version as the original binary. 173 // 174 // Returns true on successful optimization, whether or not the module is 175 // modified. Returns false if |original_binary| fails to validate or if errors 176 // occur when processing |original_binary| using any of the registered passes. 177 // In that case, no further passes are executed and the contents in 178 // |optimized_binary| may be invalid. 179 // 180 // By default, the binary is validated before any transforms are performed, 181 // and optionally after each transform. Validation uses SPIR-V spec rules 182 // for the SPIR-V version named in the binary's header (at word offset 1). 183 // Additionally, if the target environment is a client API (such as 184 // Vulkan 1.1), then validate for that client API version, to the extent 185 // that it is verifiable from data in the binary itself. 186 // 187 // It's allowed to alias |original_binary| to the start of |optimized_binary|. 188 bool Run(const uint32_t* original_binary, size_t original_binary_size, 189 std::vector<uint32_t>* optimized_binary) const; 190 191 // DEPRECATED: Same as above, except passes |options| to the validator when 192 // trying to validate the binary. If |skip_validation| is true, then the 193 // caller is guaranteeing that |original_binary| is valid, and the validator 194 // will not be run. The |max_id_bound| is the limit on the max id in the 195 // module. 196 bool Run(const uint32_t* original_binary, const size_t original_binary_size, 197 std::vector<uint32_t>* optimized_binary, 198 const ValidatorOptions& options, bool skip_validation) const; 199 200 // Same as above, except it takes an options object. See the documentation 201 // for |OptimizerOptions| to see which options can be set. 202 // 203 // By default, the binary is validated before any transforms are performed, 204 // and optionally after each transform. Validation uses SPIR-V spec rules 205 // for the SPIR-V version named in the binary's header (at word offset 1). 206 // Additionally, if the target environment is a client API (such as 207 // Vulkan 1.1), then validate for that client API version, to the extent 208 // that it is verifiable from data in the binary itself, or from the 209 // validator options set on the optimizer options. 210 bool Run(const uint32_t* original_binary, const size_t original_binary_size, 211 std::vector<uint32_t>* optimized_binary, 212 const spv_optimizer_options opt_options) const; 213 214 // Returns a vector of strings with all the pass names added to this 215 // optimizer's pass manager. These strings are valid until the associated 216 // pass manager is destroyed. 217 std::vector<const char*> GetPassNames() const; 218 219 // Sets the option to print the disassembly before each pass and after the 220 // last pass. If |out| is null, then no output is generated. Otherwise, 221 // output is sent to the |out| output stream. 222 Optimizer& SetPrintAll(std::ostream* out); 223 224 // Sets the option to print the resource utilization of each pass. If |out| 225 // is null, then no output is generated. Otherwise, output is sent to the 226 // |out| output stream. 227 Optimizer& SetTimeReport(std::ostream* out); 228 229 // Sets the option to validate the module after each pass. 230 Optimizer& SetValidateAfterAll(bool validate); 231 232 private: 233 struct Impl; // Opaque struct for holding internal data. 234 std::unique_ptr<Impl> impl_; // Unique pointer to internal data. 235 }; 236 237 // Creates a null pass. 238 // A null pass does nothing to the SPIR-V module to be optimized. 239 Optimizer::PassToken CreateNullPass(); 240 241 // Creates a strip-atomic-counter-memory pass. 242 // A strip-atomic-counter-memory pass removes all usages of the 243 // AtomicCounterMemory bit in Memory Semantics bitmasks. This bit is a no-op in 244 // Vulkan, so isn't needed in that env. And the related capability is not 245 // allowed in WebGPU, so it is not allowed in that env. 246 Optimizer::PassToken CreateStripAtomicCounterMemoryPass(); 247 248 // Creates a strip-debug-info pass. 249 // A strip-debug-info pass removes all debug instructions (as documented in 250 // Section 3.32.2 of the SPIR-V spec) of the SPIR-V module to be optimized. 251 Optimizer::PassToken CreateStripDebugInfoPass(); 252 253 // Creates a strip-reflect-info pass. 254 // A strip-reflect-info pass removes all reflections instructions. 255 // For now, this is limited to removing decorations defined in 256 // SPV_GOOGLE_hlsl_functionality1. The coverage may expand in 257 // the future. 258 Optimizer::PassToken CreateStripReflectInfoPass(); 259 260 // Creates an eliminate-dead-functions pass. 261 // An eliminate-dead-functions pass will remove all functions that are not in 262 // the call trees rooted at entry points and exported functions. These 263 // functions are not needed because they will never be called. 264 Optimizer::PassToken CreateEliminateDeadFunctionsPass(); 265 266 // Creates an eliminate-dead-members pass. 267 // An eliminate-dead-members pass will remove all unused members of structures. 268 // This will not affect the data layout of the remaining members. 269 Optimizer::PassToken CreateEliminateDeadMembersPass(); 270 271 // Creates a set-spec-constant-default-value pass from a mapping from spec-ids 272 // to the default values in the form of string. 273 // A set-spec-constant-default-value pass sets the default values for the 274 // spec constants that have SpecId decorations (i.e., those defined by 275 // OpSpecConstant{|True|False} instructions). 276 Optimizer::PassToken CreateSetSpecConstantDefaultValuePass( 277 const std::unordered_map<uint32_t, std::string>& id_value_map); 278 279 // Creates a set-spec-constant-default-value pass from a mapping from spec-ids 280 // to the default values in the form of bit pattern. 281 // A set-spec-constant-default-value pass sets the default values for the 282 // spec constants that have SpecId decorations (i.e., those defined by 283 // OpSpecConstant{|True|False} instructions). 284 Optimizer::PassToken CreateSetSpecConstantDefaultValuePass( 285 const std::unordered_map<uint32_t, std::vector<uint32_t>>& id_value_map); 286 287 // Creates a flatten-decoration pass. 288 // A flatten-decoration pass replaces grouped decorations with equivalent 289 // ungrouped decorations. That is, it replaces each OpDecorationGroup 290 // instruction and associated OpGroupDecorate and OpGroupMemberDecorate 291 // instructions with equivalent OpDecorate and OpMemberDecorate instructions. 292 // The pass does not attempt to preserve debug information for instructions 293 // it removes. 294 Optimizer::PassToken CreateFlattenDecorationPass(); 295 296 // Creates a freeze-spec-constant-value pass. 297 // A freeze-spec-constant pass specializes the value of spec constants to 298 // their default values. This pass only processes the spec constants that have 299 // SpecId decorations (defined by OpSpecConstant, OpSpecConstantTrue, or 300 // OpSpecConstantFalse instructions) and replaces them with their normal 301 // counterparts (OpConstant, OpConstantTrue, or OpConstantFalse). The 302 // corresponding SpecId annotation instructions will also be removed. This 303 // pass does not fold the newly added normal constants and does not process 304 // other spec constants defined by OpSpecConstantComposite or 305 // OpSpecConstantOp. 306 Optimizer::PassToken CreateFreezeSpecConstantValuePass(); 307 308 // Creates a fold-spec-constant-op-and-composite pass. 309 // A fold-spec-constant-op-and-composite pass folds spec constants defined by 310 // OpSpecConstantOp or OpSpecConstantComposite instruction, to normal Constants 311 // defined by OpConstantTrue, OpConstantFalse, OpConstant, OpConstantNull, or 312 // OpConstantComposite instructions. Note that spec constants defined with 313 // OpSpecConstant, OpSpecConstantTrue, or OpSpecConstantFalse instructions are 314 // not handled, as these instructions indicate their value are not determined 315 // and can be changed in future. A spec constant is foldable if all of its 316 // value(s) can be determined from the module. E.g., an integer spec constant 317 // defined with OpSpecConstantOp instruction can be folded if its value won't 318 // change later. This pass will replace the original OpSpecContantOp instruction 319 // with an OpConstant instruction. When folding composite spec constants, 320 // new instructions may be inserted to define the components of the composite 321 // constant first, then the original spec constants will be replaced by 322 // OpConstantComposite instructions. 323 // 324 // There are some operations not supported yet: 325 // OpSConvert, OpFConvert, OpQuantizeToF16 and 326 // all the operations under Kernel capability. 327 // TODO(qining): Add support for the operations listed above. 328 Optimizer::PassToken CreateFoldSpecConstantOpAndCompositePass(); 329 330 // Creates a unify-constant pass. 331 // A unify-constant pass de-duplicates the constants. Constants with the exact 332 // same value and identical form will be unified and only one constant will 333 // be kept for each unique pair of type and value. 334 // There are several cases not handled by this pass: 335 // 1) Constants defined by OpConstantNull instructions (null constants) and 336 // constants defined by OpConstantFalse, OpConstant or OpConstantComposite 337 // with value 0 (zero-valued normal constants) are not considered equivalent. 338 // So null constants won't be used to replace zero-valued normal constants, 339 // vice versa. 340 // 2) Whenever there are decorations to the constant's result id id, the 341 // constant won't be handled, which means, it won't be used to replace any 342 // other constants, neither can other constants replace it. 343 // 3) NaN in float point format with different bit patterns are not unified. 344 Optimizer::PassToken CreateUnifyConstantPass(); 345 346 // Creates a eliminate-dead-constant pass. 347 // A eliminate-dead-constant pass removes dead constants, including normal 348 // contants defined by OpConstant, OpConstantComposite, OpConstantTrue, or 349 // OpConstantFalse and spec constants defined by OpSpecConstant, 350 // OpSpecConstantComposite, OpSpecConstantTrue, OpSpecConstantFalse or 351 // OpSpecConstantOp. 352 Optimizer::PassToken CreateEliminateDeadConstantPass(); 353 354 // Creates a strength-reduction pass. 355 // A strength-reduction pass will look for opportunities to replace an 356 // instruction with an equivalent and less expensive one. For example, 357 // multiplying by a power of 2 can be replaced by a bit shift. 358 Optimizer::PassToken CreateStrengthReductionPass(); 359 360 // Creates a block merge pass. 361 // This pass searches for blocks with a single Branch to a block with no 362 // other predecessors and merges the blocks into a single block. Continue 363 // blocks and Merge blocks are not candidates for the second block. 364 // 365 // The pass is most useful after Dead Branch Elimination, which can leave 366 // such sequences of blocks. Merging them makes subsequent passes more 367 // effective, such as single block local store-load elimination. 368 // 369 // While this pass reduces the number of occurrences of this sequence, at 370 // this time it does not guarantee all such sequences are eliminated. 371 // 372 // Presence of phi instructions can inhibit this optimization. Handling 373 // these is left for future improvements. 374 Optimizer::PassToken CreateBlockMergePass(); 375 376 // Creates an exhaustive inline pass. 377 // An exhaustive inline pass attempts to exhaustively inline all function 378 // calls in all functions in an entry point call tree. The intent is to enable, 379 // albeit through brute force, analysis and optimization across function 380 // calls by subsequent optimization passes. As the inlining is exhaustive, 381 // there is no attempt to optimize for size or runtime performance. Functions 382 // that are not in the call tree of an entry point are not changed. 383 Optimizer::PassToken CreateInlineExhaustivePass(); 384 385 // Creates an opaque inline pass. 386 // An opaque inline pass inlines all function calls in all functions in all 387 // entry point call trees where the called function contains an opaque type 388 // in either its parameter types or return type. An opaque type is currently 389 // defined as Image, Sampler or SampledImage. The intent is to enable, albeit 390 // through brute force, analysis and optimization across these function calls 391 // by subsequent passes in order to remove the storing of opaque types which is 392 // not legal in Vulkan. Functions that are not in the call tree of an entry 393 // point are not changed. 394 Optimizer::PassToken CreateInlineOpaquePass(); 395 396 // Creates a single-block local variable load/store elimination pass. 397 // For every entry point function, do single block memory optimization of 398 // function variables referenced only with non-access-chain loads and stores. 399 // For each targeted variable load, if previous store to that variable in the 400 // block, replace the load's result id with the value id of the store. 401 // If previous load within the block, replace the current load's result id 402 // with the previous load's result id. In either case, delete the current 403 // load. Finally, check if any remaining stores are useless, and delete store 404 // and variable if possible. 405 // 406 // The presence of access chain references and function calls can inhibit 407 // the above optimization. 408 // 409 // Only modules with relaxed logical addressing (see opt/instruction.h) are 410 // currently processed. 411 // 412 // This pass is most effective if preceeded by Inlining and 413 // LocalAccessChainConvert. This pass will reduce the work needed to be done 414 // by LocalSingleStoreElim and LocalMultiStoreElim. 415 // 416 // Only functions in the call tree of an entry point are processed. 417 Optimizer::PassToken CreateLocalSingleBlockLoadStoreElimPass(); 418 419 // Create dead branch elimination pass. 420 // For each entry point function, this pass will look for SelectionMerge 421 // BranchConditionals with constant condition and convert to a Branch to 422 // the indicated label. It will delete resulting dead blocks. 423 // 424 // For all phi functions in merge block, replace all uses with the id 425 // corresponding to the living predecessor. 426 // 427 // Note that some branches and blocks may be left to avoid creating invalid 428 // control flow. Improving this is left to future work. 429 // 430 // This pass is most effective when preceeded by passes which eliminate 431 // local loads and stores, effectively propagating constant values where 432 // possible. 433 Optimizer::PassToken CreateDeadBranchElimPass(); 434 435 // Creates an SSA local variable load/store elimination pass. 436 // For every entry point function, eliminate all loads and stores of function 437 // scope variables only referenced with non-access-chain loads and stores. 438 // Eliminate the variables as well. 439 // 440 // The presence of access chain references and function calls can inhibit 441 // the above optimization. 442 // 443 // Only shader modules with relaxed logical addressing (see opt/instruction.h) 444 // are currently processed. Currently modules with any extensions enabled are 445 // not processed. This is left for future work. 446 // 447 // This pass is most effective if preceeded by Inlining and 448 // LocalAccessChainConvert. LocalSingleStoreElim and LocalSingleBlockElim 449 // will reduce the work that this pass has to do. 450 Optimizer::PassToken CreateLocalMultiStoreElimPass(); 451 452 // Creates a local access chain conversion pass. 453 // A local access chain conversion pass identifies all function scope 454 // variables which are accessed only with loads, stores and access chains 455 // with constant indices. It then converts all loads and stores of such 456 // variables into equivalent sequences of loads, stores, extracts and inserts. 457 // 458 // This pass only processes entry point functions. It currently only converts 459 // non-nested, non-ptr access chains. It does not process modules with 460 // non-32-bit integer types present. Optional memory access options on loads 461 // and stores are ignored as we are only processing function scope variables. 462 // 463 // This pass unifies access to these variables to a single mode and simplifies 464 // subsequent analysis and elimination of these variables along with their 465 // loads and stores allowing values to propagate to their points of use where 466 // possible. 467 Optimizer::PassToken CreateLocalAccessChainConvertPass(); 468 469 // Creates a local single store elimination pass. 470 // For each entry point function, this pass eliminates loads and stores for 471 // function scope variable that are stored to only once, where possible. Only 472 // whole variable loads and stores are eliminated; access-chain references are 473 // not optimized. Replace all loads of such variables with the value that is 474 // stored and eliminate any resulting dead code. 475 // 476 // Currently, the presence of access chains and function calls can inhibit this 477 // pass, however the Inlining and LocalAccessChainConvert passes can make it 478 // more effective. In additional, many non-load/store memory operations are 479 // not supported and will prohibit optimization of a function. Support of 480 // these operations are future work. 481 // 482 // Only shader modules with relaxed logical addressing (see opt/instruction.h) 483 // are currently processed. 484 // 485 // This pass will reduce the work needed to be done by LocalSingleBlockElim 486 // and LocalMultiStoreElim and can improve the effectiveness of other passes 487 // such as DeadBranchElimination which depend on values for their analysis. 488 Optimizer::PassToken CreateLocalSingleStoreElimPass(); 489 490 // Creates an insert/extract elimination pass. 491 // This pass processes each entry point function in the module, searching for 492 // extracts on a sequence of inserts. It further searches the sequence for an 493 // insert with indices identical to the extract. If such an insert can be 494 // found before hitting a conflicting insert, the extract's result id is 495 // replaced with the id of the values from the insert. 496 // 497 // Besides removing extracts this pass enables subsequent dead code elimination 498 // passes to delete the inserts. This pass performs best after access chains are 499 // converted to inserts and extracts and local loads and stores are eliminated. 500 Optimizer::PassToken CreateInsertExtractElimPass(); 501 502 // Creates a dead insert elimination pass. 503 // This pass processes each entry point function in the module, searching for 504 // unreferenced inserts into composite types. These are most often unused 505 // stores to vector components. They are unused because they are never 506 // referenced, or because there is another insert to the same component between 507 // the insert and the reference. After removing the inserts, dead code 508 // elimination is attempted on the inserted values. 509 // 510 // This pass performs best after access chains are converted to inserts and 511 // extracts and local loads and stores are eliminated. While executing this 512 // pass can be advantageous on its own, it is also advantageous to execute 513 // this pass after CreateInsertExtractPass() as it will remove any unused 514 // inserts created by that pass. 515 Optimizer::PassToken CreateDeadInsertElimPass(); 516 517 // Create aggressive dead code elimination pass 518 // This pass eliminates unused code from the module. In addition, 519 // it detects and eliminates code which may have spurious uses but which do 520 // not contribute to the output of the function. The most common cause of 521 // such code sequences is summations in loops whose result is no longer used 522 // due to dead code elimination. This optimization has additional compile 523 // time cost over standard dead code elimination. 524 // 525 // This pass only processes entry point functions. It also only processes 526 // shaders with relaxed logical addressing (see opt/instruction.h). It 527 // currently will not process functions with function calls. Unreachable 528 // functions are deleted. 529 // 530 // This pass will be made more effective by first running passes that remove 531 // dead control flow and inlines function calls. 532 // 533 // This pass can be especially useful after running Local Access Chain 534 // Conversion, which tends to cause cycles of dead code to be left after 535 // Store/Load elimination passes are completed. These cycles cannot be 536 // eliminated with standard dead code elimination. 537 Optimizer::PassToken CreateAggressiveDCEPass(); 538 539 // Creates an empty pass. 540 // This is deprecated and will be removed. 541 // TODO(jaebaek): remove this pass after handling glslang's broken unit tests. 542 // https://github.com/KhronosGroup/glslang/pull/2440 543 Optimizer::PassToken CreatePropagateLineInfoPass(); 544 545 // Creates an empty pass. 546 // This is deprecated and will be removed. 547 // TODO(jaebaek): remove this pass after handling glslang's broken unit tests. 548 // https://github.com/KhronosGroup/glslang/pull/2440 549 Optimizer::PassToken CreateRedundantLineInfoElimPass(); 550 551 // Creates a compact ids pass. 552 // The pass remaps result ids to a compact and gapless range starting from %1. 553 Optimizer::PassToken CreateCompactIdsPass(); 554 555 // Creates a remove duplicate pass. 556 // This pass removes various duplicates: 557 // * duplicate capabilities; 558 // * duplicate extended instruction imports; 559 // * duplicate types; 560 // * duplicate decorations. 561 Optimizer::PassToken CreateRemoveDuplicatesPass(); 562 563 // Creates a CFG cleanup pass. 564 // This pass removes cruft from the control flow graph of functions that are 565 // reachable from entry points and exported functions. It currently includes the 566 // following functionality: 567 // 568 // - Removal of unreachable basic blocks. 569 Optimizer::PassToken CreateCFGCleanupPass(); 570 571 // Create dead variable elimination pass. 572 // This pass will delete module scope variables, along with their decorations, 573 // that are not referenced. 574 Optimizer::PassToken CreateDeadVariableEliminationPass(); 575 576 // create merge return pass. 577 // changes functions that have multiple return statements so they have a single 578 // return statement. 579 // 580 // for structured control flow it is assumed that the only unreachable blocks in 581 // the function are trivial merge and continue blocks. 582 // 583 // a trivial merge block contains the label and an opunreachable instructions, 584 // nothing else. a trivial continue block contain a label and an opbranch to 585 // the header, nothing else. 586 // 587 // these conditions are guaranteed to be met after running dead-branch 588 // elimination. 589 Optimizer::PassToken CreateMergeReturnPass(); 590 591 // Create value numbering pass. 592 // This pass will look for instructions in the same basic block that compute the 593 // same value, and remove the redundant ones. 594 Optimizer::PassToken CreateLocalRedundancyEliminationPass(); 595 596 // Create LICM pass. 597 // This pass will look for invariant instructions inside loops and hoist them to 598 // the loops preheader. 599 Optimizer::PassToken CreateLoopInvariantCodeMotionPass(); 600 601 // Creates a loop fission pass. 602 // This pass will split all top level loops whose register pressure exceedes the 603 // given |threshold|. 604 Optimizer::PassToken CreateLoopFissionPass(size_t threshold); 605 606 // Creates a loop fusion pass. 607 // This pass will look for adjacent loops that are compatible and legal to be 608 // fused. The fuse all such loops as long as the register usage for the fused 609 // loop stays under the threshold defined by |max_registers_per_loop|. 610 Optimizer::PassToken CreateLoopFusionPass(size_t max_registers_per_loop); 611 612 // Creates a loop peeling pass. 613 // This pass will look for conditions inside a loop that are true or false only 614 // for the N first or last iteration. For loop with such condition, those N 615 // iterations of the loop will be executed outside of the main loop. 616 // To limit code size explosion, the loop peeling can only happen if the code 617 // size growth for each loop is under |code_growth_threshold|. 618 Optimizer::PassToken CreateLoopPeelingPass(); 619 620 // Creates a loop unswitch pass. 621 // This pass will look for loop independent branch conditions and move the 622 // condition out of the loop and version the loop based on the taken branch. 623 // Works best after LICM and local multi store elimination pass. 624 Optimizer::PassToken CreateLoopUnswitchPass(); 625 626 // Create global value numbering pass. 627 // This pass will look for instructions where the same value is computed on all 628 // paths leading to the instruction. Those instructions are deleted. 629 Optimizer::PassToken CreateRedundancyEliminationPass(); 630 631 // Create scalar replacement pass. 632 // This pass replaces composite function scope variables with variables for each 633 // element if those elements are accessed individually. The parameter is a 634 // limit on the number of members in the composite variable that the pass will 635 // consider replacing. 636 Optimizer::PassToken CreateScalarReplacementPass(uint32_t size_limit = 100); 637 638 // Create a private to local pass. 639 // This pass looks for variables delcared in the private storage class that are 640 // used in only one function. Those variables are moved to the function storage 641 // class in the function that they are used. 642 Optimizer::PassToken CreatePrivateToLocalPass(); 643 644 // Creates a conditional constant propagation (CCP) pass. 645 // This pass implements the SSA-CCP algorithm in 646 // 647 // Constant propagation with conditional branches, 648 // Wegman and Zadeck, ACM TOPLAS 13(2):181-210. 649 // 650 // Constant values in expressions and conditional jumps are folded and 651 // simplified. This may reduce code size by removing never executed jump targets 652 // and computations with constant operands. 653 Optimizer::PassToken CreateCCPPass(); 654 655 // Creates a workaround driver bugs pass. This pass attempts to work around 656 // a known driver bug (issue #1209) by identifying the bad code sequences and 657 // rewriting them. 658 // 659 // Current workaround: Avoid OpUnreachable instructions in loops. 660 Optimizer::PassToken CreateWorkaround1209Pass(); 661 662 // Creates a pass that converts if-then-else like assignments into OpSelect. 663 Optimizer::PassToken CreateIfConversionPass(); 664 665 // Creates a pass that will replace instructions that are not valid for the 666 // current shader stage by constants. Has no effect on non-shader modules. 667 Optimizer::PassToken CreateReplaceInvalidOpcodePass(); 668 669 // Creates a pass that simplifies instructions using the instruction folder. 670 Optimizer::PassToken CreateSimplificationPass(); 671 672 // Create loop unroller pass. 673 // Creates a pass to unroll loops which have the "Unroll" loop control 674 // mask set. The loops must meet a specific criteria in order to be unrolled 675 // safely this criteria is checked before doing the unroll by the 676 // LoopUtils::CanPerformUnroll method. Any loop that does not meet the criteria 677 // won't be unrolled. See CanPerformUnroll LoopUtils.h for more information. 678 Optimizer::PassToken CreateLoopUnrollPass(bool fully_unroll, int factor = 0); 679 680 // Create the SSA rewrite pass. 681 // This pass converts load/store operations on function local variables into 682 // operations on SSA IDs. This allows SSA optimizers to act on these variables. 683 // Only variables that are local to the function and of supported types are 684 // processed (see IsSSATargetVar for details). 685 Optimizer::PassToken CreateSSARewritePass(); 686 687 // Create pass to convert relaxed precision instructions to half precision. 688 // This pass converts as many relaxed float32 arithmetic operations to half as 689 // possible. It converts any float32 operands to half if needed. It converts 690 // any resulting half precision values back to float32 as needed. No variables 691 // are changed. No image operations are changed. 692 // 693 // Best if run after function scope store/load and composite operation 694 // eliminations are run. Also best if followed by instruction simplification, 695 // redundancy elimination and DCE. 696 Optimizer::PassToken CreateConvertRelaxedToHalfPass(); 697 698 // Create relax float ops pass. 699 // This pass decorates all float32 result instructions with RelaxedPrecision 700 // if not already so decorated. 701 Optimizer::PassToken CreateRelaxFloatOpsPass(); 702 703 // Create copy propagate arrays pass. 704 // This pass looks to copy propagate memory references for arrays. It looks 705 // for specific code patterns to recognize array copies. 706 Optimizer::PassToken CreateCopyPropagateArraysPass(); 707 708 // Create a vector dce pass. 709 // This pass looks for components of vectors that are unused, and removes them 710 // from the vector. Note this would still leave around lots of dead code that 711 // a pass of ADCE will be able to remove. 712 Optimizer::PassToken CreateVectorDCEPass(); 713 714 // Create a pass to reduce the size of loads. 715 // This pass looks for loads of structures where only a few of its members are 716 // used. It replaces the loads feeding an OpExtract with an OpAccessChain and 717 // a load of the specific elements. 718 Optimizer::PassToken CreateReduceLoadSizePass(); 719 720 // Create a pass to combine chained access chains. 721 // This pass looks for access chains fed by other access chains and combines 722 // them into a single instruction where possible. 723 Optimizer::PassToken CreateCombineAccessChainsPass(); 724 725 // Create a pass to instrument bindless descriptor checking 726 // This pass instruments all bindless references to check that descriptor 727 // array indices are inbounds, and if the descriptor indexing extension is 728 // enabled, that the descriptor has been initialized. If the reference is 729 // invalid, a record is written to the debug output buffer (if space allows) 730 // and a null value is returned. This pass is designed to support bindless 731 // validation in the Vulkan validation layers. 732 // 733 // TODO(greg-lunarg): Add support for buffer references. Currently only does 734 // checking for image references. 735 // 736 // Dead code elimination should be run after this pass as the original, 737 // potentially invalid code is not removed and could cause undefined behavior, 738 // including crashes. It may also be beneficial to run Simplification 739 // (ie Constant Propagation), DeadBranchElim and BlockMerge after this pass to 740 // optimize instrument code involving the testing of compile-time constants. 741 // It is also generally recommended that this pass (and all 742 // instrumentation passes) be run after any legalization and optimization 743 // passes. This will give better analysis for the instrumentation and avoid 744 // potentially de-optimizing the instrument code, for example, inlining 745 // the debug record output function throughout the module. 746 // 747 // The instrumentation will read and write buffers in debug 748 // descriptor set |desc_set|. It will write |shader_id| in each output record 749 // to identify the shader module which generated the record. 750 // |input_length_enable| controls instrumentation of runtime descriptor array 751 // references, and |input_init_enable| controls instrumentation of descriptor 752 // initialization checking, both of which require input buffer support. 753 Optimizer::PassToken CreateInstBindlessCheckPass( 754 uint32_t desc_set, uint32_t shader_id, bool input_length_enable = false, 755 bool input_init_enable = false, bool input_buff_oob_enable = false); 756 757 // Create a pass to instrument physical buffer address checking 758 // This pass instruments all physical buffer address references to check that 759 // all referenced bytes fall in a valid buffer. If the reference is 760 // invalid, a record is written to the debug output buffer (if space allows) 761 // and a null value is returned. This pass is designed to support buffer 762 // address validation in the Vulkan validation layers. 763 // 764 // Dead code elimination should be run after this pass as the original, 765 // potentially invalid code is not removed and could cause undefined behavior, 766 // including crashes. Instruction simplification would likely also be 767 // beneficial. It is also generally recommended that this pass (and all 768 // instrumentation passes) be run after any legalization and optimization 769 // passes. This will give better analysis for the instrumentation and avoid 770 // potentially de-optimizing the instrument code, for example, inlining 771 // the debug record output function throughout the module. 772 // 773 // The instrumentation will read and write buffers in debug 774 // descriptor set |desc_set|. It will write |shader_id| in each output record 775 // to identify the shader module which generated the record. 776 Optimizer::PassToken CreateInstBuffAddrCheckPass(uint32_t desc_set, 777 uint32_t shader_id); 778 779 // Create a pass to instrument OpDebugPrintf instructions. 780 // This pass replaces all OpDebugPrintf instructions with instructions to write 781 // a record containing the string id and the all specified values into a special 782 // printf output buffer (if space allows). This pass is designed to support 783 // the printf validation in the Vulkan validation layers. 784 // 785 // The instrumentation will write buffers in debug descriptor set |desc_set|. 786 // It will write |shader_id| in each output record to identify the shader 787 // module which generated the record. 788 Optimizer::PassToken CreateInstDebugPrintfPass(uint32_t desc_set, 789 uint32_t shader_id); 790 791 // Create a pass to upgrade to the VulkanKHR memory model. 792 // This pass upgrades the Logical GLSL450 memory model to Logical VulkanKHR. 793 // Additionally, it modifies memory, image, atomic and barrier operations to 794 // conform to that model's requirements. 795 Optimizer::PassToken CreateUpgradeMemoryModelPass(); 796 797 // Create a pass to do code sinking. Code sinking is a transformation 798 // where an instruction is moved into a more deeply nested construct. 799 Optimizer::PassToken CreateCodeSinkingPass(); 800 801 // Create a pass to adds initializers for OpVariable calls that require them 802 // in WebGPU. Currently this pass naively initializes variables that are 803 // missing an initializer with a null value. In the future it may initialize 804 // variables to the first value stored in them, if that is a constant. 805 Optimizer::PassToken CreateGenerateWebGPUInitializersPass(); 806 807 // Create a pass to fix incorrect storage classes. In order to make code 808 // generation simpler, DXC may generate code where the storage classes do not 809 // match up correctly. This pass will fix the errors that it can. 810 Optimizer::PassToken CreateFixStorageClassPass(); 811 812 // Create a pass to legalize OpVectorShuffle operands going into WebGPU. WebGPU 813 // forbids using 0xFFFFFFFF, which indicates an undefined result, so this pass 814 // converts those literals to 0. 815 Optimizer::PassToken CreateLegalizeVectorShufflePass(); 816 817 // Create a pass to decompose initialized variables into a seperate variable 818 // declaration and an initial store. 819 Optimizer::PassToken CreateDecomposeInitializedVariablesPass(); 820 821 // Create a pass to attempt to split up invalid unreachable merge-blocks and 822 // continue-targets to legalize for WebGPU. 823 Optimizer::PassToken CreateSplitInvalidUnreachablePass(); 824 825 // Creates a graphics robust access pass. 826 // 827 // This pass injects code to clamp indexed accesses to buffers and internal 828 // arrays, providing guarantees satisfying Vulkan's robustBufferAccess rules. 829 // 830 // TODO(dneto): Clamps coordinates and sample index for pointer calculations 831 // into storage images (OpImageTexelPointer). For an cube array image, it 832 // assumes the maximum layer count times 6 is at most 0xffffffff. 833 // 834 // NOTE: This pass will fail with a message if: 835 // - The module is not a Shader module. 836 // - The module declares VariablePointers, VariablePointersStorageBuffer, or 837 // RuntimeDescriptorArrayEXT capabilities. 838 // - The module uses an addressing model other than Logical 839 // - Access chain indices are wider than 64 bits. 840 // - Access chain index for a struct is not an OpConstant integer or is out 841 // of range. (The module is already invalid if that is the case.) 842 // - TODO(dneto): The OpImageTexelPointer coordinate component is not 32-bits 843 // wide. 844 // 845 // NOTE: Access chain indices are always treated as signed integers. So 846 // if an array has a fixed size of more than 2^31 elements, then elements 847 // from 2^31 and above are never accessible with a 32-bit index, 848 // signed or unsigned. For this case, this pass will clamp the index 849 // between 0 and at 2^31-1, inclusive. 850 // Similarly, if an array has more then 2^15 element and is accessed with 851 // a 16-bit index, then elements from 2^15 and above are not accessible. 852 // In this case, the pass will clamp the index between 0 and 2^15-1 853 // inclusive. 854 Optimizer::PassToken CreateGraphicsRobustAccessPass(); 855 856 // Create descriptor scalar replacement pass. 857 // This pass replaces every array variable |desc| that has a DescriptorSet and 858 // Binding decorations with a new variable for each element of the array. 859 // Suppose |desc| was bound at binding |b|. Then the variable corresponding to 860 // |desc[i]| will have binding |b+i|. The descriptor set will be the same. It 861 // is assumed that no other variable already has a binding that will used by one 862 // of the new variables. If not, the pass will generate invalid Spir-V. All 863 // accesses to |desc| must be OpAccessChain instructions with a literal index 864 // for the first index. 865 Optimizer::PassToken CreateDescriptorScalarReplacementPass(); 866 867 // Create a pass to replace each OpKill instruction with a function call to a 868 // function that has a single OpKill. Also replace each OpTerminateInvocation 869 // instruction with a function call to a function that has a single 870 // OpTerminateInvocation. This allows more code to be inlined. 871 Optimizer::PassToken CreateWrapOpKillPass(); 872 873 // Replaces the extensions VK_AMD_shader_ballot,VK_AMD_gcn_shader, and 874 // VK_AMD_shader_trinary_minmax with equivalent code using core instructions and 875 // capabilities. 876 Optimizer::PassToken CreateAmdExtToKhrPass(); 877 878 } // namespace spvtools 879 880 #endif // INCLUDE_SPIRV_TOOLS_OPTIMIZER_HPP_ 881