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