1 //===- GPUDialect.cpp - MLIR Dialect for GPU Kernels implementation -------===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 //
9 // This file implements the GPU kernel-related dialect and its operations.
10 //
11 //===----------------------------------------------------------------------===//
12 
13 #include "mlir/Dialect/GPU/GPUDialect.h"
14 
15 #include "mlir/Dialect/Arithmetic/IR/Arithmetic.h"
16 #include "mlir/Dialect/LLVMIR/LLVMDialect.h"
17 #include "mlir/Dialect/MemRef/IR/MemRef.h"
18 #include "mlir/Dialect/StandardOps/IR/Ops.h"
19 #include "mlir/IR/Attributes.h"
20 #include "mlir/IR/Builders.h"
21 #include "mlir/IR/BuiltinOps.h"
22 #include "mlir/IR/BuiltinTypes.h"
23 #include "mlir/IR/DialectImplementation.h"
24 #include "mlir/IR/FunctionImplementation.h"
25 #include "mlir/IR/Matchers.h"
26 #include "mlir/IR/OpImplementation.h"
27 #include "mlir/IR/PatternMatch.h"
28 #include "mlir/IR/TypeUtilities.h"
29 #include "mlir/Transforms/InliningUtils.h"
30 #include "llvm/ADT/TypeSwitch.h"
31 
32 using namespace mlir;
33 using namespace mlir::gpu;
34 
35 #include "mlir/Dialect/GPU/GPUOpsDialect.cpp.inc"
36 
37 //===----------------------------------------------------------------------===//
38 // MMAMatrixType
39 //===----------------------------------------------------------------------===//
40 
41 MMAMatrixType MMAMatrixType::get(ArrayRef<int64_t> shape, Type elementType,
42                                  StringRef operand) {
43   return Base::get(elementType.getContext(), shape, elementType, operand);
44 }
45 
46 MMAMatrixType
47 MMAMatrixType::getChecked(function_ref<InFlightDiagnostic()> emitError,
48                           ArrayRef<int64_t> shape, Type elementType,
49                           StringRef operand) {
50   return Base::getChecked(emitError, elementType.getContext(), shape,
51                           elementType, operand);
52 }
53 
54 unsigned MMAMatrixType::getNumDims() const { return getImpl()->numDims; }
55 
56 ArrayRef<int64_t> MMAMatrixType::getShape() const {
57   return getImpl()->getShape();
58 }
59 
60 Type MMAMatrixType::getElementType() const { return getImpl()->elementType; }
61 
62 StringRef MMAMatrixType::getOperand() const { return getImpl()->getOperand(); }
63 
64 bool MMAMatrixType::isValidElementType(Type elementType) {
65   return elementType.isF16() || elementType.isF32();
66 }
67 
68 LogicalResult
69 MMAMatrixType::verify(function_ref<InFlightDiagnostic()> emitError,
70                       ArrayRef<int64_t> shape, Type elementType,
71                       StringRef operand) {
72   if (!operand.equals("AOp") && !operand.equals("BOp") &&
73       !operand.equals("COp"))
74     return emitError() << "operand expected to be one of AOp, BOp or COp";
75 
76   if (shape.size() != 2)
77     return emitError() << "MMAMatrixType must have exactly two dimensions";
78 
79   if (!MMAMatrixType::isValidElementType(elementType))
80     return emitError() << "MMAMatrixType elements must be F16 or F32";
81 
82   return success();
83 }
84 
85 //===----------------------------------------------------------------------===//
86 // GPUDialect
87 //===----------------------------------------------------------------------===//
88 
89 /// GPU memory space identifiers.
90 enum GPUMemorySpace {
91   /// Generic memory space identifier.
92   kGenericMemorySpace = 0,
93 
94   /// Global memory space identifier.
95   kGlobalMemorySpace = 1,
96 
97   /// Shared memory space identifier.
98   kSharedMemorySpace = 3
99 };
100 
101 bool GPUDialect::isKernel(Operation *op) {
102   UnitAttr isKernelAttr = op->getAttrOfType<UnitAttr>(getKernelFuncAttrName());
103   return static_cast<bool>(isKernelAttr);
104 }
105 
106 namespace {
107 /// This class defines the interface for handling inlining with gpu
108 /// operations.
109 struct GPUInlinerInterface : public DialectInlinerInterface {
110   using DialectInlinerInterface::DialectInlinerInterface;
111 
112   /// All gpu dialect ops can be inlined.
113   bool isLegalToInline(Operation *, Region *, bool,
114                        BlockAndValueMapping &) const final {
115     return true;
116   }
117 };
118 } // namespace
119 
120 void GPUDialect::initialize() {
121   addTypes<AsyncTokenType>();
122   addTypes<MMAMatrixType>();
123   addOperations<
124 #define GET_OP_LIST
125 #include "mlir/Dialect/GPU/GPUOps.cpp.inc"
126       >();
127   addInterfaces<GPUInlinerInterface>();
128 }
129 
130 Type GPUDialect::parseType(DialectAsmParser &parser) const {
131   // Parse the main keyword for the type.
132   StringRef keyword;
133   if (parser.parseKeyword(&keyword))
134     return Type();
135   MLIRContext *context = getContext();
136 
137   // Handle 'async token' types.
138   if (keyword == "async.token")
139     return AsyncTokenType::get(context);
140 
141   if (keyword == "mma_matrix") {
142     llvm::SMLoc beginLoc = parser.getNameLoc();
143 
144     // Parse '<'.
145     if (parser.parseLess())
146       return nullptr;
147 
148     // Parse the size and elementType.
149     SmallVector<int64_t> shape;
150     Type elementType;
151     if (parser.parseDimensionList(shape, /*allowDynamic=*/false) ||
152         parser.parseType(elementType))
153       return nullptr;
154 
155     // Parse ','
156     if (parser.parseComma())
157       return nullptr;
158 
159     // Parse operand.
160     std::string operand;
161     if (failed(parser.parseOptionalString(&operand)))
162       return nullptr;
163 
164     // Parse '>'.
165     if (parser.parseGreater())
166       return nullptr;
167 
168     return MMAMatrixType::getChecked(mlir::detail::getDefaultDiagnosticEmitFn(
169                                          parser.getEncodedSourceLoc(beginLoc)),
170                                      shape, elementType, operand);
171   }
172 
173   parser.emitError(parser.getNameLoc(), "unknown gpu type: " + keyword);
174   return Type();
175 }
176 
177 void GPUDialect::printType(Type type, DialectAsmPrinter &os) const {
178   TypeSwitch<Type>(type)
179       .Case<AsyncTokenType>([&](Type) { os << "async.token"; })
180       .Case<MMAMatrixType>([&](MMAMatrixType fragTy) {
181         os << "mma_matrix<";
182         auto shape = fragTy.getShape();
183         for (auto dim = shape.begin(), e = shape.end() - 1; dim != e; ++dim)
184           os << *dim << 'x';
185         os << shape.back() << 'x' << fragTy.getElementType();
186         os << ", \"" << fragTy.getOperand() << "\"" << '>';
187       })
188       .Default([](Type) { llvm_unreachable("unexpected 'gpu' type kind"); });
189 }
190 
191 LogicalResult GPUDialect::verifyOperationAttribute(Operation *op,
192                                                    NamedAttribute attr) {
193   if (!attr.getValue().isa<UnitAttr>() ||
194       attr.getName() != getContainerModuleAttrName())
195     return success();
196 
197   auto module = dyn_cast<ModuleOp>(op);
198   if (!module)
199     return op->emitError("expected '")
200            << getContainerModuleAttrName() << "' attribute to be attached to '"
201            << ModuleOp::getOperationName() << '\'';
202 
203   auto walkResult = module.walk([&module](LaunchFuncOp launchOp) -> WalkResult {
204     // Ignore launches that are nested more or less deep than functions in the
205     // module we are currently checking.
206     if (!launchOp->getParentOp() ||
207         launchOp->getParentOp()->getParentOp() != module)
208       return success();
209 
210     // Ignore launch ops with missing attributes here. The errors will be
211     // reported by the verifiers of those ops.
212     if (!launchOp->getAttrOfType<SymbolRefAttr>(
213             LaunchFuncOp::getKernelAttrName()))
214       return success();
215 
216     // Check that `launch_func` refers to a well-formed GPU kernel module.
217     StringAttr kernelModuleName = launchOp.getKernelModuleName();
218     auto kernelModule = module.lookupSymbol<GPUModuleOp>(kernelModuleName);
219     if (!kernelModule)
220       return launchOp.emitOpError()
221              << "kernel module '" << kernelModuleName.getValue()
222              << "' is undefined";
223 
224     // Check that `launch_func` refers to a well-formed kernel function.
225     Operation *kernelFunc = module.lookupSymbol(launchOp.kernelAttr());
226     auto kernelGPUFunction = dyn_cast_or_null<gpu::GPUFuncOp>(kernelFunc);
227     auto kernelLLVMFunction = dyn_cast_or_null<LLVM::LLVMFuncOp>(kernelFunc);
228     if (!kernelGPUFunction && !kernelLLVMFunction)
229       return launchOp.emitOpError("kernel function '")
230              << launchOp.kernel() << "' is undefined";
231     if (!kernelFunc->getAttrOfType<mlir::UnitAttr>(
232             GPUDialect::getKernelFuncAttrName()))
233       return launchOp.emitOpError("kernel function is missing the '")
234              << GPUDialect::getKernelFuncAttrName() << "' attribute";
235 
236     // TODO: if the kernel function has been converted to
237     // the LLVM dialect but the caller hasn't (which happens during the
238     // separate compilation), do not check type correspondence as it would
239     // require the verifier to be aware of the LLVM type conversion.
240     if (kernelLLVMFunction)
241       return success();
242 
243     unsigned actualNumArguments = launchOp.getNumKernelOperands();
244     unsigned expectedNumArguments = kernelGPUFunction.getNumArguments();
245     if (expectedNumArguments != actualNumArguments)
246       return launchOp.emitOpError("got ")
247              << actualNumArguments << " kernel operands but expected "
248              << expectedNumArguments;
249 
250     auto functionType = kernelGPUFunction.getType();
251     for (unsigned i = 0; i < expectedNumArguments; ++i) {
252       if (launchOp.getKernelOperand(i).getType() != functionType.getInput(i)) {
253         return launchOp.emitOpError("type of function argument ")
254                << i << " does not match";
255       }
256     }
257 
258     return success();
259   });
260 
261   return walkResult.wasInterrupted() ? failure() : success();
262 }
263 
264 template <typename T>
265 static LogicalResult verifyIndexOp(T op) {
266   auto dimension = op.dimension();
267   if (dimension != "x" && dimension != "y" && dimension != "z")
268     return op.emitError("dimension \"") << dimension << "\" is invalid";
269   return success();
270 }
271 
272 static LogicalResult verifyAllReduce(gpu::AllReduceOp allReduce) {
273   if (allReduce.body().empty() != allReduce.op().hasValue())
274     return allReduce.emitError(
275         "expected either an op attribute or a non-empty body");
276   if (!allReduce.body().empty()) {
277     if (allReduce.body().getNumArguments() != 2)
278       return allReduce.emitError("expected two region arguments");
279     for (auto argument : allReduce.body().getArguments()) {
280       if (argument.getType() != allReduce.getType())
281         return allReduce.emitError("incorrect region argument type");
282     }
283     unsigned yieldCount = 0;
284     for (Block &block : allReduce.body()) {
285       if (auto yield = dyn_cast<gpu::YieldOp>(block.getTerminator())) {
286         if (yield.getNumOperands() != 1)
287           return allReduce.emitError("expected one gpu.yield operand");
288         if (yield.getOperand(0).getType() != allReduce.getType())
289           return allReduce.emitError("incorrect gpu.yield type");
290         ++yieldCount;
291       }
292     }
293     if (yieldCount == 0)
294       return allReduce.emitError("expected gpu.yield op in region");
295   } else {
296     StringRef opName = *allReduce.op();
297     if ((opName == "and" || opName == "or" || opName == "xor") &&
298         !allReduce.getType().isa<IntegerType>()) {
299       return allReduce.emitError()
300              << '`' << opName << '`'
301              << " accumulator is only compatible with Integer type";
302     }
303   }
304   return success();
305 }
306 
307 static LogicalResult verifyShuffleOp(gpu::ShuffleOp shuffleOp) {
308   auto type = shuffleOp.value().getType();
309   if (shuffleOp.result().getType() != type) {
310     return shuffleOp.emitOpError()
311            << "requires the same type for value operand and result";
312   }
313   if (!type.isSignlessIntOrFloat() || type.getIntOrFloatBitWidth() != 32) {
314     return shuffleOp.emitOpError()
315            << "requires value operand type to be f32 or i32";
316   }
317   return success();
318 }
319 
320 static void printShuffleOp(OpAsmPrinter &p, ShuffleOp op) {
321   p << ' ' << op.getOperands() << ' ' << stringifyEnum(op.mode()) << " : "
322     << op.value().getType();
323 }
324 
325 static ParseResult parseShuffleOp(OpAsmParser &parser, OperationState &state) {
326   SmallVector<OpAsmParser::OperandType, 3> operandInfo;
327   if (parser.parseOperandList(operandInfo, 3))
328     return failure();
329 
330   StringRef mode;
331   if (parser.parseKeyword(&mode))
332     return failure();
333   state.addAttribute("mode", parser.getBuilder().getStringAttr(mode));
334 
335   Type valueType;
336   Type int32Type = parser.getBuilder().getIntegerType(32);
337   Type int1Type = parser.getBuilder().getI1Type();
338   if (parser.parseColonType(valueType) ||
339       parser.resolveOperands(operandInfo, {valueType, int32Type, int32Type},
340                              parser.getCurrentLocation(), state.operands) ||
341       parser.addTypesToList({valueType, int1Type}, state.types))
342     return failure();
343   return success();
344 }
345 
346 //===----------------------------------------------------------------------===//
347 // AsyncOpInterface
348 //===----------------------------------------------------------------------===//
349 
350 void gpu::addAsyncDependency(Operation *op, Value token) {
351   op->insertOperands(0, {token});
352   if (!op->template hasTrait<OpTrait::AttrSizedOperandSegments>())
353     return;
354   auto attrName =
355       OpTrait::AttrSizedOperandSegments<void>::getOperandSegmentSizeAttr();
356   auto sizeAttr = op->template getAttrOfType<DenseIntElementsAttr>(attrName);
357 
358   // Async dependencies is the only variadic operand.
359   if (!sizeAttr)
360     return;
361 
362   SmallVector<int32_t, 8> sizes(sizeAttr.getValues<int32_t>());
363   ++sizes.front();
364   op->setAttr(attrName, Builder(op->getContext()).getI32VectorAttr(sizes));
365 }
366 
367 //===----------------------------------------------------------------------===//
368 // LaunchOp
369 //===----------------------------------------------------------------------===//
370 
371 void LaunchOp::build(OpBuilder &builder, OperationState &result,
372                      Value gridSizeX, Value gridSizeY, Value gridSizeZ,
373                      Value blockSizeX, Value blockSizeY, Value blockSizeZ,
374                      Value dynamicSharedMemorySize) {
375   // Add grid and block sizes as op operands, followed by the data operands.
376   result.addOperands(
377       {gridSizeX, gridSizeY, gridSizeZ, blockSizeX, blockSizeY, blockSizeZ});
378   if (dynamicSharedMemorySize)
379     result.addOperands(dynamicSharedMemorySize);
380 
381   // Create a kernel body region with kNumConfigRegionAttributes + N arguments,
382   // where the first kNumConfigRegionAttributes arguments have `index` type and
383   // the rest have the same types as the data operands.
384   Region *kernelRegion = result.addRegion();
385   Block *body = new Block();
386   body->addArguments(
387       std::vector<Type>(kNumConfigRegionAttributes, builder.getIndexType()));
388   kernelRegion->push_back(body);
389 }
390 
391 KernelDim3 LaunchOp::getBlockIds() {
392   assert(!body().empty() && "LaunchOp body must not be empty.");
393   auto args = body().getArguments();
394   return KernelDim3{args[0], args[1], args[2]};
395 }
396 
397 KernelDim3 LaunchOp::getThreadIds() {
398   assert(!body().empty() && "LaunchOp body must not be empty.");
399   auto args = body().getArguments();
400   return KernelDim3{args[3], args[4], args[5]};
401 }
402 
403 KernelDim3 LaunchOp::getGridSize() {
404   assert(!body().empty() && "LaunchOp body must not be empty.");
405   auto args = body().getArguments();
406   return KernelDim3{args[6], args[7], args[8]};
407 }
408 
409 KernelDim3 LaunchOp::getBlockSize() {
410   assert(!body().empty() && "LaunchOp body must not be empty.");
411   auto args = body().getArguments();
412   return KernelDim3{args[9], args[10], args[11]};
413 }
414 
415 KernelDim3 LaunchOp::getGridSizeOperandValues() {
416   return KernelDim3{getOperand(0), getOperand(1), getOperand(2)};
417 }
418 
419 KernelDim3 LaunchOp::getBlockSizeOperandValues() {
420   return KernelDim3{getOperand(3), getOperand(4), getOperand(5)};
421 }
422 
423 static LogicalResult verify(LaunchOp op) {
424   // Kernel launch takes kNumConfigOperands leading operands for grid/block
425   // sizes and transforms them into kNumConfigRegionAttributes region arguments
426   // for block/thread identifiers and grid/block sizes.
427   if (!op.body().empty()) {
428     if (op.body().getNumArguments() !=
429         LaunchOp::kNumConfigOperands + op.getNumOperands() -
430             (op.dynamicSharedMemorySize() ? 1 : 0))
431       return op.emitOpError("unexpected number of region arguments");
432   }
433 
434   // Block terminators without successors are expected to exit the kernel region
435   // and must be `gpu.terminator`.
436   for (Block &block : op.body()) {
437     if (block.empty())
438       continue;
439     if (block.back().getNumSuccessors() != 0)
440       continue;
441     if (!isa<gpu::TerminatorOp>(&block.back())) {
442       return block.back()
443           .emitError()
444           .append("expected '", gpu::TerminatorOp::getOperationName(),
445                   "' or a terminator with successors")
446           .attachNote(op.getLoc())
447           .append("in '", LaunchOp::getOperationName(), "' body region");
448     }
449   }
450 
451   return success();
452 }
453 
454 // Pretty-print the kernel grid/block size assignment as
455 //   (%iter-x, %iter-y, %iter-z) in
456 //   (%size-x = %ssa-use, %size-y = %ssa-use, %size-z = %ssa-use)
457 // where %size-* and %iter-* will correspond to the body region arguments.
458 static void printSizeAssignment(OpAsmPrinter &p, KernelDim3 size,
459                                 KernelDim3 operands, KernelDim3 ids) {
460   p << '(' << ids.x << ", " << ids.y << ", " << ids.z << ") in (";
461   p << size.x << " = " << operands.x << ", ";
462   p << size.y << " = " << operands.y << ", ";
463   p << size.z << " = " << operands.z << ')';
464 }
465 
466 static void printLaunchOp(OpAsmPrinter &p, LaunchOp op) {
467   // Print the launch configuration.
468   p << ' ' << op.getBlocksKeyword();
469   printSizeAssignment(p, op.getGridSize(), op.getGridSizeOperandValues(),
470                       op.getBlockIds());
471   p << ' ' << op.getThreadsKeyword();
472   printSizeAssignment(p, op.getBlockSize(), op.getBlockSizeOperandValues(),
473                       op.getThreadIds());
474   if (op.dynamicSharedMemorySize())
475     p << ' ' << op.getDynamicSharedMemorySizeKeyword() << ' '
476       << op.dynamicSharedMemorySize();
477 
478   p.printRegion(op.body(), /*printEntryBlockArgs=*/false);
479   p.printOptionalAttrDict(op->getAttrs());
480 }
481 
482 // Parse the size assignment blocks for blocks and threads.  These have the form
483 //   (%region_arg, %region_arg, %region_arg) in
484 //   (%region_arg = %operand, %region_arg = %operand, %region_arg = %operand)
485 // where %region_arg are percent-identifiers for the region arguments to be
486 // introduced further (SSA defs), and %operand are percent-identifiers for the
487 // SSA value uses.
488 static ParseResult
489 parseSizeAssignment(OpAsmParser &parser,
490                     MutableArrayRef<OpAsmParser::OperandType> sizes,
491                     MutableArrayRef<OpAsmParser::OperandType> regionSizes,
492                     MutableArrayRef<OpAsmParser::OperandType> indices) {
493   assert(indices.size() == 3 && "space for three indices expected");
494   SmallVector<OpAsmParser::OperandType, 3> args;
495   if (parser.parseRegionArgumentList(args, /*requiredOperandCount=*/3,
496                                      OpAsmParser::Delimiter::Paren) ||
497       parser.parseKeyword("in") || parser.parseLParen())
498     return failure();
499   std::move(args.begin(), args.end(), indices.begin());
500 
501   for (int i = 0; i < 3; ++i) {
502     if (i != 0 && parser.parseComma())
503       return failure();
504     if (parser.parseRegionArgument(regionSizes[i]) || parser.parseEqual() ||
505         parser.parseOperand(sizes[i]))
506       return failure();
507   }
508 
509   return parser.parseRParen();
510 }
511 
512 // Parses a Launch operation.
513 // operation ::= `gpu.launch` `blocks` `(` ssa-id-list `)` `in` ssa-reassignment
514 //                           `threads` `(` ssa-id-list `)` `in` ssa-reassignment
515 //                            region attr-dict?
516 // ssa-reassignment ::= `(` ssa-id `=` ssa-use (`,` ssa-id `=` ssa-use)* `)`
517 static ParseResult parseLaunchOp(OpAsmParser &parser, OperationState &result) {
518   // Sizes of the grid and block.
519   SmallVector<OpAsmParser::OperandType, LaunchOp::kNumConfigOperands> sizes(
520       LaunchOp::kNumConfigOperands);
521   MutableArrayRef<OpAsmParser::OperandType> sizesRef(sizes);
522 
523   // Actual (data) operands passed to the kernel.
524   SmallVector<OpAsmParser::OperandType, 4> dataOperands;
525 
526   // Region arguments to be created.
527   SmallVector<OpAsmParser::OperandType, 16> regionArgs(
528       LaunchOp::kNumConfigRegionAttributes);
529   MutableArrayRef<OpAsmParser::OperandType> regionArgsRef(regionArgs);
530 
531   // Parse the size assignment segments: the first segment assigns grid sizes
532   // and defines values for block identifiers; the second segment assigns block
533   // sizes and defines values for thread identifiers.  In the region argument
534   // list, identifiers precede sizes, and block-related values precede
535   // thread-related values.
536   if (parser.parseKeyword(LaunchOp::getBlocksKeyword().data()) ||
537       parseSizeAssignment(parser, sizesRef.take_front(3),
538                           regionArgsRef.slice(6, 3),
539                           regionArgsRef.slice(0, 3)) ||
540       parser.parseKeyword(LaunchOp::getThreadsKeyword().data()) ||
541       parseSizeAssignment(parser, sizesRef.drop_front(3),
542                           regionArgsRef.slice(9, 3),
543                           regionArgsRef.slice(3, 3)) ||
544       parser.resolveOperands(sizes, parser.getBuilder().getIndexType(),
545                              result.operands))
546     return failure();
547 
548   OpAsmParser::OperandType dynamicSharedMemorySize;
549   if (!parser.parseOptionalKeyword(
550           LaunchOp::getDynamicSharedMemorySizeKeyword()))
551     if (parser.parseOperand(dynamicSharedMemorySize) ||
552         parser.resolveOperand(dynamicSharedMemorySize,
553                               parser.getBuilder().getI32Type(),
554                               result.operands))
555       return failure();
556 
557   // Introduce the body region and parse it. The region has
558   // kNumConfigRegionAttributes arguments that correspond to
559   // block/thread identifiers and grid/block sizes, all of the `index` type.
560   Type index = parser.getBuilder().getIndexType();
561   SmallVector<Type, LaunchOp::kNumConfigRegionAttributes> dataTypes(
562       LaunchOp::kNumConfigRegionAttributes, index);
563   Region *body = result.addRegion();
564   return failure(parser.parseRegion(*body, regionArgs, dataTypes) ||
565                  parser.parseOptionalAttrDict(result.attributes));
566 }
567 
568 /// Simplify the gpu.launch when the range of a thread or block ID is
569 /// trivially known to be one.
570 struct FoldLaunchArguments : public OpRewritePattern<LaunchOp> {
571   using OpRewritePattern<LaunchOp>::OpRewritePattern;
572   LogicalResult matchAndRewrite(LaunchOp op,
573                                 PatternRewriter &rewriter) const override {
574     // If the range implies a single value for `id`, replace `id`'s uses by
575     // zero.
576     Value zero;
577     bool simplified = false;
578     auto constPropIdUses = [&](Value id, Value size) {
579       // Check if size is trivially one.
580       if (!matchPattern(size, m_One()))
581         return;
582       if (!simplified) {
583         // Create a zero value the first time.
584         OpBuilder::InsertionGuard guard(rewriter);
585         rewriter.setInsertionPointToStart(&op.body().front());
586         zero =
587             rewriter.create<arith::ConstantIndexOp>(op.getLoc(), /*value=*/0);
588       }
589       id.replaceAllUsesWith(zero);
590       simplified = true;
591     };
592     constPropIdUses(op.getBlockIds().x, op.gridSizeX());
593     constPropIdUses(op.getBlockIds().y, op.gridSizeY());
594     constPropIdUses(op.getBlockIds().z, op.gridSizeZ());
595     constPropIdUses(op.getThreadIds().x, op.blockSizeX());
596     constPropIdUses(op.getThreadIds().y, op.blockSizeY());
597     constPropIdUses(op.getThreadIds().z, op.blockSizeZ());
598 
599     return success(simplified);
600   }
601 };
602 
603 void LaunchOp::getCanonicalizationPatterns(RewritePatternSet &rewrites,
604                                            MLIRContext *context) {
605   rewrites.add<FoldLaunchArguments>(context);
606 }
607 
608 //===----------------------------------------------------------------------===//
609 // LaunchFuncOp
610 //===----------------------------------------------------------------------===//
611 
612 void LaunchFuncOp::build(OpBuilder &builder, OperationState &result,
613                          GPUFuncOp kernelFunc, KernelDim3 gridSize,
614                          KernelDim3 blockSize, Value dynamicSharedMemorySize,
615                          ValueRange kernelOperands) {
616   // Add grid and block sizes as op operands, followed by the data operands.
617   result.addOperands({gridSize.x, gridSize.y, gridSize.z, blockSize.x,
618                       blockSize.y, blockSize.z});
619   if (dynamicSharedMemorySize)
620     result.addOperands(dynamicSharedMemorySize);
621   result.addOperands(kernelOperands);
622   auto kernelModule = kernelFunc->getParentOfType<GPUModuleOp>();
623   auto kernelSymbol =
624       SymbolRefAttr::get(kernelModule.getNameAttr(),
625                          {SymbolRefAttr::get(kernelFunc.getNameAttr())});
626   result.addAttribute(getKernelAttrName(), kernelSymbol);
627   SmallVector<int32_t, 9> segmentSizes(9, 1);
628   segmentSizes.front() = 0; // Initially no async dependencies.
629   segmentSizes[segmentSizes.size() - 2] = dynamicSharedMemorySize ? 1 : 0;
630   segmentSizes.back() = static_cast<int32_t>(kernelOperands.size());
631   result.addAttribute(getOperandSegmentSizeAttr(),
632                       builder.getI32VectorAttr(segmentSizes));
633 }
634 
635 unsigned LaunchFuncOp::getNumKernelOperands() {
636   return getNumOperands() - asyncDependencies().size() - kNumConfigOperands -
637          (dynamicSharedMemorySize() ? 1 : 0);
638 }
639 
640 StringAttr LaunchFuncOp::getKernelModuleName() {
641   return kernel().getRootReference();
642 }
643 
644 StringAttr LaunchFuncOp::getKernelName() { return kernel().getLeafReference(); }
645 
646 Value LaunchFuncOp::getKernelOperand(unsigned i) {
647   return getOperand(asyncDependencies().size() + kNumConfigOperands +
648                     (dynamicSharedMemorySize() ? 1 : 0) + i);
649 }
650 
651 KernelDim3 LaunchFuncOp::getGridSizeOperandValues() {
652   auto operands = getOperands().drop_front(asyncDependencies().size());
653   return KernelDim3{operands[0], operands[1], operands[2]};
654 }
655 
656 KernelDim3 LaunchFuncOp::getBlockSizeOperandValues() {
657   auto operands = getOperands().drop_front(asyncDependencies().size());
658   return KernelDim3{operands[3], operands[4], operands[5]};
659 }
660 
661 static LogicalResult verify(LaunchFuncOp op) {
662   auto module = op->getParentOfType<ModuleOp>();
663   if (!module)
664     return op.emitOpError("expected to belong to a module");
665 
666   if (!module->getAttrOfType<UnitAttr>(
667           GPUDialect::getContainerModuleAttrName()))
668     return op.emitOpError(
669         "expected the closest surrounding module to have the '" +
670         GPUDialect::getContainerModuleAttrName() + "' attribute");
671 
672   auto kernelAttr = op->getAttrOfType<SymbolRefAttr>(op.getKernelAttrName());
673   if (!kernelAttr)
674     return op.emitOpError("symbol reference attribute '" +
675                           op.getKernelAttrName() + "' must be specified");
676 
677   return success();
678 }
679 
680 static ParseResult
681 parseLaunchFuncOperands(OpAsmParser &parser,
682                         SmallVectorImpl<OpAsmParser::OperandType> &argNames,
683                         SmallVectorImpl<Type> &argTypes) {
684   if (parser.parseOptionalKeyword("args"))
685     return success();
686   SmallVector<NamedAttrList, 4> argAttrs;
687   bool isVariadic = false;
688   return function_like_impl::parseFunctionArgumentList(
689       parser, /*allowAttributes=*/false,
690       /*allowVariadic=*/false, argNames, argTypes, argAttrs, isVariadic);
691 }
692 
693 static void printLaunchFuncOperands(OpAsmPrinter &printer, Operation *,
694                                     OperandRange operands, TypeRange types) {
695   if (operands.empty())
696     return;
697   printer << "args(";
698   llvm::interleaveComma(llvm::zip(operands, types), printer,
699                         [&](const auto &pair) {
700                           printer.printOperand(std::get<0>(pair));
701                           printer << " : ";
702                           printer.printType(std::get<1>(pair));
703                         });
704   printer << ")";
705 }
706 
707 //===----------------------------------------------------------------------===//
708 // GPUFuncOp
709 //===----------------------------------------------------------------------===//
710 
711 /// Adds a new block argument that corresponds to buffers located in
712 /// workgroup memory.
713 BlockArgument GPUFuncOp::addWorkgroupAttribution(Type type) {
714   auto attrName = getNumWorkgroupAttributionsAttrName();
715   auto attr = (*this)->getAttrOfType<IntegerAttr>(attrName);
716   (*this)->setAttr(attrName,
717                    IntegerAttr::get(attr.getType(), attr.getValue() + 1));
718   return getBody().insertArgument(getType().getNumInputs() + attr.getInt(),
719                                   type);
720 }
721 
722 /// Adds a new block argument that corresponds to buffers located in
723 /// private memory.
724 BlockArgument GPUFuncOp::addPrivateAttribution(Type type) {
725   // Buffers on the private memory always come after buffers on the workgroup
726   // memory.
727   return getBody().addArgument(type);
728 }
729 
730 void GPUFuncOp::build(OpBuilder &builder, OperationState &result,
731                       StringRef name, FunctionType type,
732                       TypeRange workgroupAttributions,
733                       TypeRange privateAttributions,
734                       ArrayRef<NamedAttribute> attrs) {
735   result.addAttribute(SymbolTable::getSymbolAttrName(),
736                       builder.getStringAttr(name));
737   result.addAttribute(getTypeAttrName(), TypeAttr::get(type));
738   result.addAttribute(getNumWorkgroupAttributionsAttrName(),
739                       builder.getI64IntegerAttr(workgroupAttributions.size()));
740   result.addAttributes(attrs);
741   Region *body = result.addRegion();
742   Block *entryBlock = new Block;
743   entryBlock->addArguments(type.getInputs());
744   entryBlock->addArguments(workgroupAttributions);
745   entryBlock->addArguments(privateAttributions);
746 
747   body->getBlocks().push_back(entryBlock);
748 }
749 
750 /// Parses a GPU function memory attribution.
751 ///
752 /// memory-attribution ::= (`workgroup` `(` ssa-id-and-type-list `)`)?
753 ///                        (`private` `(` ssa-id-and-type-list `)`)?
754 ///
755 /// Note that this function parses only one of the two similar parts, with the
756 /// keyword provided as argument.
757 static ParseResult
758 parseAttributions(OpAsmParser &parser, StringRef keyword,
759                   SmallVectorImpl<OpAsmParser::OperandType> &args,
760                   SmallVectorImpl<Type> &argTypes) {
761   // If we could not parse the keyword, just assume empty list and succeed.
762   if (failed(parser.parseOptionalKeyword(keyword)))
763     return success();
764 
765   if (failed(parser.parseLParen()))
766     return failure();
767 
768   // Early exit for an empty list.
769   if (succeeded(parser.parseOptionalRParen()))
770     return success();
771 
772   do {
773     OpAsmParser::OperandType arg;
774     Type type;
775 
776     if (parser.parseRegionArgument(arg) || parser.parseColonType(type))
777       return failure();
778 
779     args.push_back(arg);
780     argTypes.push_back(type);
781   } while (succeeded(parser.parseOptionalComma()));
782 
783   return parser.parseRParen();
784 }
785 
786 /// Parses a GPU function.
787 ///
788 /// <operation> ::= `gpu.func` symbol-ref-id `(` argument-list `)`
789 ///                 (`->` function-result-list)? memory-attribution `kernel`?
790 ///                 function-attributes? region
791 static ParseResult parseGPUFuncOp(OpAsmParser &parser, OperationState &result) {
792   SmallVector<OpAsmParser::OperandType, 8> entryArgs;
793   SmallVector<NamedAttrList, 1> argAttrs;
794   SmallVector<NamedAttrList, 1> resultAttrs;
795   SmallVector<Type, 8> argTypes;
796   SmallVector<Type, 4> resultTypes;
797   bool isVariadic;
798 
799   // Parse the function name.
800   StringAttr nameAttr;
801   if (parser.parseSymbolName(nameAttr, ::mlir::SymbolTable::getSymbolAttrName(),
802                              result.attributes))
803     return failure();
804 
805   auto signatureLocation = parser.getCurrentLocation();
806   if (failed(function_like_impl::parseFunctionSignature(
807           parser, /*allowVariadic=*/false, entryArgs, argTypes, argAttrs,
808           isVariadic, resultTypes, resultAttrs)))
809     return failure();
810 
811   if (entryArgs.empty() && !argTypes.empty())
812     return parser.emitError(signatureLocation)
813            << "gpu.func requires named arguments";
814 
815   // Construct the function type. More types will be added to the region, but
816   // not to the function type.
817   Builder &builder = parser.getBuilder();
818   auto type = builder.getFunctionType(argTypes, resultTypes);
819   result.addAttribute(GPUFuncOp::getTypeAttrName(), TypeAttr::get(type));
820 
821   // Parse workgroup memory attributions.
822   if (failed(parseAttributions(parser, GPUFuncOp::getWorkgroupKeyword(),
823                                entryArgs, argTypes)))
824     return failure();
825 
826   // Store the number of operands we just parsed as the number of workgroup
827   // memory attributions.
828   unsigned numWorkgroupAttrs = argTypes.size() - type.getNumInputs();
829   result.addAttribute(GPUFuncOp::getNumWorkgroupAttributionsAttrName(),
830                       builder.getI64IntegerAttr(numWorkgroupAttrs));
831 
832   // Parse private memory attributions.
833   if (failed(parseAttributions(parser, GPUFuncOp::getPrivateKeyword(),
834                                entryArgs, argTypes)))
835     return failure();
836 
837   // Parse the kernel attribute if present.
838   if (succeeded(parser.parseOptionalKeyword(GPUFuncOp::getKernelKeyword())))
839     result.addAttribute(GPUDialect::getKernelFuncAttrName(),
840                         builder.getUnitAttr());
841 
842   // Parse attributes.
843   if (failed(parser.parseOptionalAttrDictWithKeyword(result.attributes)))
844     return failure();
845   function_like_impl::addArgAndResultAttrs(builder, result, argAttrs,
846                                            resultAttrs);
847 
848   // Parse the region. If no argument names were provided, take all names
849   // (including those of attributions) from the entry block.
850   auto *body = result.addRegion();
851   return parser.parseRegion(*body, entryArgs, argTypes);
852 }
853 
854 static void printAttributions(OpAsmPrinter &p, StringRef keyword,
855                               ArrayRef<BlockArgument> values) {
856   if (values.empty())
857     return;
858 
859   p << ' ' << keyword << '(';
860   llvm::interleaveComma(
861       values, p, [&p](BlockArgument v) { p << v << " : " << v.getType(); });
862   p << ')';
863 }
864 
865 /// Prints a GPU Func op.
866 static void printGPUFuncOp(OpAsmPrinter &p, GPUFuncOp op) {
867   p << ' ';
868   p.printSymbolName(op.getName());
869 
870   FunctionType type = op.getType();
871   function_like_impl::printFunctionSignature(
872       p, op.getOperation(), type.getInputs(),
873       /*isVariadic=*/false, type.getResults());
874 
875   printAttributions(p, op.getWorkgroupKeyword(), op.getWorkgroupAttributions());
876   printAttributions(p, op.getPrivateKeyword(), op.getPrivateAttributions());
877   if (op.isKernel())
878     p << ' ' << op.getKernelKeyword();
879 
880   function_like_impl::printFunctionAttributes(
881       p, op.getOperation(), type.getNumInputs(), type.getNumResults(),
882       {op.getNumWorkgroupAttributionsAttrName(),
883        GPUDialect::getKernelFuncAttrName()});
884   p.printRegion(op.getBody(), /*printEntryBlockArgs=*/false);
885 }
886 
887 /// Hook for FunctionLike verifier.
888 LogicalResult GPUFuncOp::verifyType() {
889   Type type = getTypeAttr().getValue();
890   if (!type.isa<FunctionType>())
891     return emitOpError("requires '" + getTypeAttrName() +
892                        "' attribute of function type");
893 
894   if (isKernel() && getType().getNumResults() != 0)
895     return emitOpError() << "expected void return type for kernel function";
896 
897   return success();
898 }
899 
900 static LogicalResult verifyAttributions(Operation *op,
901                                         ArrayRef<BlockArgument> attributions,
902                                         unsigned memorySpace) {
903   for (Value v : attributions) {
904     auto type = v.getType().dyn_cast<MemRefType>();
905     if (!type)
906       return op->emitOpError() << "expected memref type in attribution";
907 
908     if (type.getMemorySpaceAsInt() != memorySpace) {
909       return op->emitOpError()
910              << "expected memory space " << memorySpace << " in attribution";
911     }
912   }
913   return success();
914 }
915 
916 /// Verifies the body of the function.
917 LogicalResult GPUFuncOp::verifyBody() {
918   unsigned numFuncArguments = getNumArguments();
919   unsigned numWorkgroupAttributions = getNumWorkgroupAttributions();
920   unsigned numBlockArguments = front().getNumArguments();
921   if (numBlockArguments < numFuncArguments + numWorkgroupAttributions)
922     return emitOpError() << "expected at least "
923                          << numFuncArguments + numWorkgroupAttributions
924                          << " arguments to body region";
925 
926   ArrayRef<Type> funcArgTypes = getType().getInputs();
927   for (unsigned i = 0; i < numFuncArguments; ++i) {
928     Type blockArgType = front().getArgument(i).getType();
929     if (funcArgTypes[i] != blockArgType)
930       return emitOpError() << "expected body region argument #" << i
931                            << " to be of type " << funcArgTypes[i] << ", got "
932                            << blockArgType;
933   }
934 
935   if (failed(verifyAttributions(getOperation(), getWorkgroupAttributions(),
936                                 GPUDialect::getWorkgroupAddressSpace())) ||
937       failed(verifyAttributions(getOperation(), getPrivateAttributions(),
938                                 GPUDialect::getPrivateAddressSpace())))
939     return failure();
940 
941   return success();
942 }
943 
944 //===----------------------------------------------------------------------===//
945 // ReturnOp
946 //===----------------------------------------------------------------------===//
947 
948 static LogicalResult verify(gpu::ReturnOp returnOp) {
949   GPUFuncOp function = returnOp->getParentOfType<GPUFuncOp>();
950 
951   FunctionType funType = function.getType();
952 
953   if (funType.getNumResults() != returnOp.operands().size())
954     return returnOp.emitOpError()
955         .append("expected ", funType.getNumResults(), " result operands")
956         .attachNote(function.getLoc())
957         .append("return type declared here");
958 
959   for (const auto &pair : llvm::enumerate(
960            llvm::zip(function.getType().getResults(), returnOp.operands()))) {
961     Type type;
962     Value operand;
963     std::tie(type, operand) = pair.value();
964     if (type != operand.getType())
965       return returnOp.emitOpError() << "unexpected type `" << operand.getType()
966                                     << "' for operand #" << pair.index();
967   }
968   return success();
969 }
970 
971 //===----------------------------------------------------------------------===//
972 // GPUModuleOp
973 //===----------------------------------------------------------------------===//
974 
975 void GPUModuleOp::build(OpBuilder &builder, OperationState &result,
976                         StringRef name) {
977   ensureTerminator(*result.addRegion(), builder, result.location);
978   result.attributes.push_back(builder.getNamedAttr(
979       ::mlir::SymbolTable::getSymbolAttrName(), builder.getStringAttr(name)));
980 }
981 
982 static ParseResult parseGPUModuleOp(OpAsmParser &parser,
983                                     OperationState &result) {
984   StringAttr nameAttr;
985   if (parser.parseSymbolName(nameAttr, SymbolTable::getSymbolAttrName(),
986                              result.attributes))
987     return failure();
988 
989   // If module attributes are present, parse them.
990   if (parser.parseOptionalAttrDictWithKeyword(result.attributes))
991     return failure();
992 
993   // Parse the module body.
994   auto *body = result.addRegion();
995   if (parser.parseRegion(*body, None, None))
996     return failure();
997 
998   // Ensure that this module has a valid terminator.
999   GPUModuleOp::ensureTerminator(*body, parser.getBuilder(), result.location);
1000   return success();
1001 }
1002 
1003 static void print(OpAsmPrinter &p, GPUModuleOp op) {
1004   p << ' ';
1005   p.printSymbolName(op.getName());
1006   p.printOptionalAttrDictWithKeyword(op->getAttrs(),
1007                                      {SymbolTable::getSymbolAttrName()});
1008   p.printRegion(op->getRegion(0), /*printEntryBlockArgs=*/false,
1009                 /*printBlockTerminators=*/false);
1010 }
1011 
1012 //===----------------------------------------------------------------------===//
1013 // GPUMemcpyOp
1014 //===----------------------------------------------------------------------===//
1015 
1016 static LogicalResult verify(MemcpyOp op) {
1017   auto srcType = op.src().getType();
1018   auto dstType = op.dst().getType();
1019 
1020   if (getElementTypeOrSelf(srcType) != getElementTypeOrSelf(dstType))
1021     return op.emitOpError("arguments have incompatible element type");
1022 
1023   if (failed(verifyCompatibleShape(srcType, dstType)))
1024     return op.emitOpError("arguments have incompatible shape");
1025 
1026   return success();
1027 }
1028 
1029 static ParseResult parseAsyncDependencies(
1030     OpAsmParser &parser, Type &asyncTokenType,
1031     SmallVectorImpl<OpAsmParser::OperandType> &asyncDependencies) {
1032   auto loc = parser.getCurrentLocation();
1033   if (succeeded(parser.parseOptionalKeyword("async"))) {
1034     if (parser.getNumResults() == 0)
1035       return parser.emitError(loc, "needs to be named when marked 'async'");
1036     asyncTokenType = parser.getBuilder().getType<AsyncTokenType>();
1037   }
1038   return parser.parseOperandList(asyncDependencies,
1039                                  OpAsmParser::Delimiter::OptionalSquare);
1040 }
1041 
1042 static void printAsyncDependencies(OpAsmPrinter &printer, Operation *op,
1043                                    Type asyncTokenType,
1044                                    OperandRange asyncDependencies) {
1045   if (asyncTokenType)
1046     printer << "async ";
1047   if (asyncDependencies.empty())
1048     return;
1049   printer << "[";
1050   llvm::interleaveComma(asyncDependencies, printer);
1051   printer << "]";
1052 }
1053 
1054 //===----------------------------------------------------------------------===//
1055 // GPU_SubgroupMmaLoadMatrixOp
1056 //===----------------------------------------------------------------------===//
1057 
1058 static LogicalResult verify(SubgroupMmaLoadMatrixOp op) {
1059   auto srcType = op.srcMemref().getType();
1060   auto resType = op.res().getType();
1061   auto resMatrixType = resType.cast<gpu::MMAMatrixType>();
1062   auto operand = resMatrixType.getOperand();
1063   auto srcMemrefType = srcType.cast<MemRefType>();
1064   auto srcMemSpace = srcMemrefType.getMemorySpaceAsInt();
1065 
1066   if (!srcMemrefType.getLayout().isIdentity())
1067     return op.emitError("expected identity layout map for source memref");
1068 
1069   if (srcMemSpace != kGenericMemorySpace && srcMemSpace != kSharedMemorySpace &&
1070       srcMemSpace != kGlobalMemorySpace)
1071     return op.emitError(
1072         "source memorySpace kGenericMemorySpace, kSharedMemorySpace or "
1073         "kGlobalMemorySpace only allowed");
1074 
1075   if (!operand.equals("AOp") && !operand.equals("BOp") &&
1076       !operand.equals("COp"))
1077     return op.emitError("only AOp, BOp and COp can be loaded");
1078 
1079   return success();
1080 }
1081 
1082 //===----------------------------------------------------------------------===//
1083 // GPU_SubgroupMmaStoreMatrixOp
1084 //===----------------------------------------------------------------------===//
1085 
1086 static LogicalResult verify(SubgroupMmaStoreMatrixOp op) {
1087   auto srcType = op.src().getType();
1088   auto dstType = op.dstMemref().getType();
1089   auto srcMatrixType = srcType.cast<gpu::MMAMatrixType>();
1090   auto dstMemrefType = dstType.cast<MemRefType>();
1091   auto dstMemSpace = dstMemrefType.getMemorySpaceAsInt();
1092   if (!dstMemrefType.getLayout().isIdentity())
1093     return op.emitError("expected identity layout map for destination memref");
1094 
1095   if (dstMemSpace != kGenericMemorySpace && dstMemSpace != kSharedMemorySpace &&
1096       dstMemSpace != kGlobalMemorySpace)
1097     return op.emitError(
1098         "destination memorySpace of kGenericMemorySpace, "
1099         "kGlobalMemorySpace or kSharedMemorySpace only allowed");
1100 
1101   if (!srcMatrixType.getOperand().equals("COp"))
1102     return op.emitError(
1103         "expected the operand matrix being stored to have 'COp' operand type");
1104 
1105   return success();
1106 }
1107 
1108 //===----------------------------------------------------------------------===//
1109 // GPU_SubgroupMmaComputeOp
1110 //===----------------------------------------------------------------------===//
1111 
1112 static LogicalResult verify(SubgroupMmaComputeOp op) {
1113   enum OperandMap { A, B, C };
1114   SmallVector<MMAMatrixType, 3> opTypes;
1115 
1116   auto populateOpInfo = [&opTypes, &op]() {
1117     opTypes.push_back(op.opA().getType().cast<MMAMatrixType>());
1118     opTypes.push_back(op.opB().getType().cast<MMAMatrixType>());
1119     opTypes.push_back(op.opC().getType().cast<MMAMatrixType>());
1120   };
1121   populateOpInfo();
1122 
1123   if (!opTypes[A].getOperand().equals("AOp") ||
1124       !opTypes[B].getOperand().equals("BOp") ||
1125       !opTypes[C].getOperand().equals("COp"))
1126     return op.emitError("operands must be in the order AOp, BOp, COp");
1127 
1128   ArrayRef<int64_t> aShape, bShape, cShape;
1129   aShape = opTypes[A].getShape();
1130   bShape = opTypes[B].getShape();
1131   cShape = opTypes[C].getShape();
1132 
1133   if (aShape[1] != bShape[0] || aShape[0] != cShape[0] ||
1134       bShape[1] != cShape[1])
1135     return op.emitError("operand shapes do not satisfy matmul constraints");
1136 
1137   return success();
1138 }
1139 
1140 /// This is a common class used for patterns of the form
1141 /// "someop(memrefcast) -> someop".  It folds the source of any memref.cast
1142 /// into the root operation directly.
1143 static LogicalResult foldMemRefCast(Operation *op) {
1144   bool folded = false;
1145   for (OpOperand &operand : op->getOpOperands()) {
1146     auto cast = operand.get().getDefiningOp<mlir::memref::CastOp>();
1147     if (cast) {
1148       operand.set(cast.getOperand());
1149       folded = true;
1150     }
1151   }
1152   return success(folded);
1153 }
1154 
1155 LogicalResult MemcpyOp::fold(ArrayRef<Attribute> operands,
1156                              SmallVectorImpl<::mlir::OpFoldResult> &results) {
1157   return foldMemRefCast(*this);
1158 }
1159 
1160 LogicalResult MemsetOp::fold(ArrayRef<Attribute> operands,
1161                              SmallVectorImpl<::mlir::OpFoldResult> &results) {
1162   return foldMemRefCast(*this);
1163 }
1164 
1165 //===----------------------------------------------------------------------===//
1166 // GPU_AllocOp
1167 //===----------------------------------------------------------------------===//
1168 namespace {
1169 
1170 /// Folding of memref.dim(gpu.alloc(%size), %idx) -> %size similar to
1171 /// `memref::AllocOp`.
1172 struct SimplifyDimOfAllocOp : public OpRewritePattern<memref::DimOp> {
1173   using OpRewritePattern<memref::DimOp>::OpRewritePattern;
1174 
1175   LogicalResult matchAndRewrite(memref::DimOp dimOp,
1176                                 PatternRewriter &rewriter) const override {
1177     auto index = dimOp.index().getDefiningOp<arith::ConstantIndexOp>();
1178     if (!index)
1179       return failure();
1180 
1181     auto memrefType = dimOp.source().getType().dyn_cast<MemRefType>();
1182     if (!memrefType || !memrefType.isDynamicDim(index.value()))
1183       return failure();
1184 
1185     auto alloc = dimOp.source().getDefiningOp<AllocOp>();
1186     if (!alloc)
1187       return failure();
1188 
1189     Value substituteOp = *(alloc.dynamicSizes().begin() +
1190                            memrefType.getDynamicDimIndex(index.value()));
1191     rewriter.replaceOp(dimOp, substituteOp);
1192     return success();
1193   }
1194 };
1195 
1196 } // namespace
1197 
1198 void AllocOp::getCanonicalizationPatterns(RewritePatternSet &results,
1199                                           MLIRContext *context) {
1200   results.add<SimplifyDimOfAllocOp>(context);
1201 }
1202 
1203 #include "mlir/Dialect/GPU/GPUOpInterfaces.cpp.inc"
1204 #include "mlir/Dialect/GPU/GPUOpsEnums.cpp.inc"
1205 
1206 #define GET_OP_CLASSES
1207 #include "mlir/Dialect/GPU/GPUOps.cpp.inc"
1208