1 //===----------------------------------------------------------------------===//
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 #include "mlir/Dialect/Arithmetic/IR/Arithmetic.h"
10 #include "mlir/Dialect/Arithmetic/Utils/Utils.h"
11 #include "mlir/Dialect/MemRef/IR/MemRef.h"
12 #include "mlir/Dialect/MemRef/Utils/MemRefUtils.h"
13 #include "mlir/Dialect/Utils/StaticValueUtils.h"
14 #include "mlir/IR/AffineMap.h"
15 #include "mlir/IR/Builders.h"
16 #include "mlir/IR/BuiltinTypes.h"
17 #include "mlir/IR/Matchers.h"
18 #include "mlir/IR/PatternMatch.h"
19 #include "mlir/IR/TypeUtilities.h"
20 #include "mlir/Interfaces/InferTypeOpInterface.h"
21 #include "mlir/Interfaces/ViewLikeInterface.h"
22 #include "llvm/ADT/STLExtras.h"
23 
24 using namespace mlir;
25 using namespace mlir::memref;
26 
27 /// Materialize a single constant operation from a given attribute value with
28 /// the desired resultant type.
29 Operation *MemRefDialect::materializeConstant(OpBuilder &builder,
30                                               Attribute value, Type type,
31                                               Location loc) {
32   if (arith::ConstantOp::isBuildableWith(value, type))
33     return builder.create<arith::ConstantOp>(loc, value, type);
34   return nullptr;
35 }
36 
37 //===----------------------------------------------------------------------===//
38 // Common canonicalization pattern support logic
39 //===----------------------------------------------------------------------===//
40 
41 /// This is a common class used for patterns of the form
42 /// "someop(memrefcast) -> someop".  It folds the source of any memref.cast
43 /// into the root operation directly.
44 LogicalResult mlir::memref::foldMemRefCast(Operation *op, Value inner) {
45   bool folded = false;
46   for (OpOperand &operand : op->getOpOperands()) {
47     auto cast = operand.get().getDefiningOp<CastOp>();
48     if (cast && operand.get() != inner &&
49         !cast.getOperand().getType().isa<UnrankedMemRefType>()) {
50       operand.set(cast.getOperand());
51       folded = true;
52     }
53   }
54   return success(folded);
55 }
56 
57 /// Return an unranked/ranked tensor type for the given unranked/ranked memref
58 /// type.
59 Type mlir::memref::getTensorTypeFromMemRefType(Type type) {
60   if (auto memref = type.dyn_cast<MemRefType>())
61     return RankedTensorType::get(memref.getShape(), memref.getElementType());
62   if (auto memref = type.dyn_cast<UnrankedMemRefType>())
63     return UnrankedTensorType::get(memref.getElementType());
64   return NoneType::get(type.getContext());
65 }
66 
67 LogicalResult memref::CastOp::verify() {
68   return impl::verifyCastOp(*this, areCastCompatible);
69 }
70 
71 //===----------------------------------------------------------------------===//
72 // AllocOp / AllocaOp
73 //===----------------------------------------------------------------------===//
74 
75 template <typename AllocLikeOp>
76 static LogicalResult verifyAllocLikeOp(AllocLikeOp op) {
77   static_assert(llvm::is_one_of<AllocLikeOp, AllocOp, AllocaOp>::value,
78                 "applies to only alloc or alloca");
79   auto memRefType = op.getResult().getType().template dyn_cast<MemRefType>();
80   if (!memRefType)
81     return op.emitOpError("result must be a memref");
82 
83   if (static_cast<int64_t>(op.dynamicSizes().size()) !=
84       memRefType.getNumDynamicDims())
85     return op.emitOpError("dimension operand count does not equal memref "
86                           "dynamic dimension count");
87 
88   unsigned numSymbols = 0;
89   if (!memRefType.getLayout().isIdentity())
90     numSymbols = memRefType.getLayout().getAffineMap().getNumSymbols();
91   if (op.symbolOperands().size() != numSymbols)
92     return op.emitOpError("symbol operand count does not equal memref symbol "
93                           "count: expected ")
94            << numSymbols << ", got " << op.symbolOperands().size();
95 
96   return success();
97 }
98 
99 LogicalResult AllocOp::verify() { return verifyAllocLikeOp(*this); }
100 
101 LogicalResult AllocaOp::verify() {
102   // An alloca op needs to have an ancestor with an allocation scope trait.
103   if (!(*this)->getParentWithTrait<OpTrait::AutomaticAllocationScope>())
104     return emitOpError(
105         "requires an ancestor op with AutomaticAllocationScope trait");
106 
107   return verifyAllocLikeOp(*this);
108 }
109 
110 namespace {
111 /// Fold constant dimensions into an alloc like operation.
112 template <typename AllocLikeOp>
113 struct SimplifyAllocConst : public OpRewritePattern<AllocLikeOp> {
114   using OpRewritePattern<AllocLikeOp>::OpRewritePattern;
115 
116   LogicalResult matchAndRewrite(AllocLikeOp alloc,
117                                 PatternRewriter &rewriter) const override {
118     // Check to see if any dimensions operands are constants.  If so, we can
119     // substitute and drop them.
120     if (llvm::none_of(alloc.dynamicSizes(), [](Value operand) {
121           return matchPattern(operand, matchConstantIndex());
122         }))
123       return failure();
124 
125     auto memrefType = alloc.getType();
126 
127     // Ok, we have one or more constant operands.  Collect the non-constant ones
128     // and keep track of the resultant memref type to build.
129     SmallVector<int64_t, 4> newShapeConstants;
130     newShapeConstants.reserve(memrefType.getRank());
131     SmallVector<Value, 4> dynamicSizes;
132 
133     unsigned dynamicDimPos = 0;
134     for (unsigned dim = 0, e = memrefType.getRank(); dim < e; ++dim) {
135       int64_t dimSize = memrefType.getDimSize(dim);
136       // If this is already static dimension, keep it.
137       if (dimSize != -1) {
138         newShapeConstants.push_back(dimSize);
139         continue;
140       }
141       auto dynamicSize = alloc.dynamicSizes()[dynamicDimPos];
142       auto *defOp = dynamicSize.getDefiningOp();
143       if (auto constantIndexOp =
144               dyn_cast_or_null<arith::ConstantIndexOp>(defOp)) {
145         // Dynamic shape dimension will be folded.
146         newShapeConstants.push_back(constantIndexOp.value());
147       } else {
148         // Dynamic shape dimension not folded; copy dynamicSize from old memref.
149         newShapeConstants.push_back(-1);
150         dynamicSizes.push_back(dynamicSize);
151       }
152       dynamicDimPos++;
153     }
154 
155     // Create new memref type (which will have fewer dynamic dimensions).
156     MemRefType newMemRefType =
157         MemRefType::Builder(memrefType).setShape(newShapeConstants);
158     assert(static_cast<int64_t>(dynamicSizes.size()) ==
159            newMemRefType.getNumDynamicDims());
160 
161     // Create and insert the alloc op for the new memref.
162     auto newAlloc = rewriter.create<AllocLikeOp>(
163         alloc.getLoc(), newMemRefType, dynamicSizes, alloc.symbolOperands(),
164         alloc.alignmentAttr());
165     // Insert a cast so we have the same type as the old alloc.
166     auto resultCast =
167         rewriter.create<CastOp>(alloc.getLoc(), newAlloc, alloc.getType());
168 
169     rewriter.replaceOp(alloc, {resultCast});
170     return success();
171   }
172 };
173 
174 /// Fold alloc operations with no users or only store and dealloc uses.
175 template <typename T>
176 struct SimplifyDeadAlloc : public OpRewritePattern<T> {
177   using OpRewritePattern<T>::OpRewritePattern;
178 
179   LogicalResult matchAndRewrite(T alloc,
180                                 PatternRewriter &rewriter) const override {
181     if (llvm::any_of(alloc->getUsers(), [&](Operation *op) {
182           if (auto storeOp = dyn_cast<StoreOp>(op))
183             return storeOp.value() == alloc;
184           return !isa<DeallocOp>(op);
185         }))
186       return failure();
187 
188     for (Operation *user : llvm::make_early_inc_range(alloc->getUsers()))
189       rewriter.eraseOp(user);
190 
191     rewriter.eraseOp(alloc);
192     return success();
193   }
194 };
195 } // namespace
196 
197 void AllocOp::getCanonicalizationPatterns(RewritePatternSet &results,
198                                           MLIRContext *context) {
199   results.add<SimplifyAllocConst<AllocOp>, SimplifyDeadAlloc<AllocOp>>(context);
200 }
201 
202 void AllocaOp::getCanonicalizationPatterns(RewritePatternSet &results,
203                                            MLIRContext *context) {
204   results.add<SimplifyAllocConst<AllocaOp>, SimplifyDeadAlloc<AllocaOp>>(
205       context);
206 }
207 
208 //===----------------------------------------------------------------------===//
209 // AllocaScopeOp
210 //===----------------------------------------------------------------------===//
211 
212 static void print(OpAsmPrinter &p, AllocaScopeOp &op) {
213   bool printBlockTerminators = false;
214 
215   p << ' ';
216   if (!op.results().empty()) {
217     p << " -> (" << op.getResultTypes() << ")";
218     printBlockTerminators = true;
219   }
220   p << ' ';
221   p.printRegion(op.bodyRegion(),
222                 /*printEntryBlockArgs=*/false,
223                 /*printBlockTerminators=*/printBlockTerminators);
224   p.printOptionalAttrDict(op->getAttrs());
225 }
226 
227 static ParseResult parseAllocaScopeOp(OpAsmParser &parser,
228                                       OperationState &result) {
229   // Create a region for the body.
230   result.regions.reserve(1);
231   Region *bodyRegion = result.addRegion();
232 
233   // Parse optional results type list.
234   if (parser.parseOptionalArrowTypeList(result.types))
235     return failure();
236 
237   // Parse the body region.
238   if (parser.parseRegion(*bodyRegion, /*arguments=*/{}, /*argTypes=*/{}))
239     return failure();
240   AllocaScopeOp::ensureTerminator(*bodyRegion, parser.getBuilder(),
241                                   result.location);
242 
243   // Parse the optional attribute list.
244   if (parser.parseOptionalAttrDict(result.attributes))
245     return failure();
246 
247   return success();
248 }
249 
250 LogicalResult AllocaScopeOp::verify() {
251   return RegionBranchOpInterface::verifyTypes(*this);
252 }
253 
254 void AllocaScopeOp::getSuccessorRegions(
255     Optional<unsigned> index, ArrayRef<Attribute> operands,
256     SmallVectorImpl<RegionSuccessor> &regions) {
257   if (index.hasValue()) {
258     regions.push_back(RegionSuccessor(getResults()));
259     return;
260   }
261 
262   regions.push_back(RegionSuccessor(&bodyRegion()));
263 }
264 
265 //===----------------------------------------------------------------------===//
266 // AssumeAlignmentOp
267 //===----------------------------------------------------------------------===//
268 
269 LogicalResult AssumeAlignmentOp::verify() {
270   if (!llvm::isPowerOf2_32(alignment()))
271     return emitOpError("alignment must be power of 2");
272   return success();
273 }
274 
275 //===----------------------------------------------------------------------===//
276 // CastOp
277 //===----------------------------------------------------------------------===//
278 
279 /// Determines whether MemRef_CastOp casts to a more dynamic version of the
280 /// source memref. This is useful to to fold a memref.cast into a consuming op
281 /// and implement canonicalization patterns for ops in different dialects that
282 /// may consume the results of memref.cast operations. Such foldable memref.cast
283 /// operations are typically inserted as `view` and `subview` ops are
284 /// canonicalized, to preserve the type compatibility of their uses.
285 ///
286 /// Returns true when all conditions are met:
287 /// 1. source and result are ranked memrefs with strided semantics and same
288 /// element type and rank.
289 /// 2. each of the source's size, offset or stride has more static information
290 /// than the corresponding result's size, offset or stride.
291 ///
292 /// Example 1:
293 /// ```mlir
294 ///   %1 = memref.cast %0 : memref<8x16xf32> to memref<?x?xf32>
295 ///   %2 = consumer %1 ... : memref<?x?xf32> ...
296 /// ```
297 ///
298 /// may fold into:
299 ///
300 /// ```mlir
301 ///   %2 = consumer %0 ... : memref<8x16xf32> ...
302 /// ```
303 ///
304 /// Example 2:
305 /// ```
306 ///   %1 = memref.cast %0 : memref<?x16xf32, affine_map<(i, j)->(16 * i + j)>>
307 ///          to memref<?x?xf32>
308 ///   consumer %1 : memref<?x?xf32> ...
309 /// ```
310 ///
311 /// may fold into:
312 ///
313 /// ```
314 ///   consumer %0 ... : memref<?x16xf32, affine_map<(i, j)->(16 * i + j)>>
315 /// ```
316 bool CastOp::canFoldIntoConsumerOp(CastOp castOp) {
317   MemRefType sourceType = castOp.source().getType().dyn_cast<MemRefType>();
318   MemRefType resultType = castOp.getType().dyn_cast<MemRefType>();
319 
320   // Requires ranked MemRefType.
321   if (!sourceType || !resultType)
322     return false;
323 
324   // Requires same elemental type.
325   if (sourceType.getElementType() != resultType.getElementType())
326     return false;
327 
328   // Requires same rank.
329   if (sourceType.getRank() != resultType.getRank())
330     return false;
331 
332   // Only fold casts between strided memref forms.
333   int64_t sourceOffset, resultOffset;
334   SmallVector<int64_t, 4> sourceStrides, resultStrides;
335   if (failed(getStridesAndOffset(sourceType, sourceStrides, sourceOffset)) ||
336       failed(getStridesAndOffset(resultType, resultStrides, resultOffset)))
337     return false;
338 
339   // If cast is towards more static sizes along any dimension, don't fold.
340   for (auto it : llvm::zip(sourceType.getShape(), resultType.getShape())) {
341     auto ss = std::get<0>(it), st = std::get<1>(it);
342     if (ss != st)
343       if (ShapedType::isDynamic(ss) && !ShapedType::isDynamic(st))
344         return false;
345   }
346 
347   // If cast is towards more static offset along any dimension, don't fold.
348   if (sourceOffset != resultOffset)
349     if (ShapedType::isDynamicStrideOrOffset(sourceOffset) &&
350         !ShapedType::isDynamicStrideOrOffset(resultOffset))
351       return false;
352 
353   // If cast is towards more static strides along any dimension, don't fold.
354   for (auto it : llvm::zip(sourceStrides, resultStrides)) {
355     auto ss = std::get<0>(it), st = std::get<1>(it);
356     if (ss != st)
357       if (ShapedType::isDynamicStrideOrOffset(ss) &&
358           !ShapedType::isDynamicStrideOrOffset(st))
359         return false;
360   }
361 
362   return true;
363 }
364 
365 bool CastOp::areCastCompatible(TypeRange inputs, TypeRange outputs) {
366   if (inputs.size() != 1 || outputs.size() != 1)
367     return false;
368   Type a = inputs.front(), b = outputs.front();
369   auto aT = a.dyn_cast<MemRefType>();
370   auto bT = b.dyn_cast<MemRefType>();
371 
372   auto uaT = a.dyn_cast<UnrankedMemRefType>();
373   auto ubT = b.dyn_cast<UnrankedMemRefType>();
374 
375   if (aT && bT) {
376     if (aT.getElementType() != bT.getElementType())
377       return false;
378     if (aT.getLayout() != bT.getLayout()) {
379       int64_t aOffset, bOffset;
380       SmallVector<int64_t, 4> aStrides, bStrides;
381       if (failed(getStridesAndOffset(aT, aStrides, aOffset)) ||
382           failed(getStridesAndOffset(bT, bStrides, bOffset)) ||
383           aStrides.size() != bStrides.size())
384         return false;
385 
386       // Strides along a dimension/offset are compatible if the value in the
387       // source memref is static and the value in the target memref is the
388       // same. They are also compatible if either one is dynamic (see
389       // description of MemRefCastOp for details).
390       auto checkCompatible = [](int64_t a, int64_t b) {
391         return (a == MemRefType::getDynamicStrideOrOffset() ||
392                 b == MemRefType::getDynamicStrideOrOffset() || a == b);
393       };
394       if (!checkCompatible(aOffset, bOffset))
395         return false;
396       for (const auto &aStride : enumerate(aStrides))
397         if (!checkCompatible(aStride.value(), bStrides[aStride.index()]))
398           return false;
399     }
400     if (aT.getMemorySpace() != bT.getMemorySpace())
401       return false;
402 
403     // They must have the same rank, and any specified dimensions must match.
404     if (aT.getRank() != bT.getRank())
405       return false;
406 
407     for (unsigned i = 0, e = aT.getRank(); i != e; ++i) {
408       int64_t aDim = aT.getDimSize(i), bDim = bT.getDimSize(i);
409       if (aDim != -1 && bDim != -1 && aDim != bDim)
410         return false;
411     }
412     return true;
413   } else {
414     if (!aT && !uaT)
415       return false;
416     if (!bT && !ubT)
417       return false;
418     // Unranked to unranked casting is unsupported
419     if (uaT && ubT)
420       return false;
421 
422     auto aEltType = (aT) ? aT.getElementType() : uaT.getElementType();
423     auto bEltType = (bT) ? bT.getElementType() : ubT.getElementType();
424     if (aEltType != bEltType)
425       return false;
426 
427     auto aMemSpace = (aT) ? aT.getMemorySpace() : uaT.getMemorySpace();
428     auto bMemSpace = (bT) ? bT.getMemorySpace() : ubT.getMemorySpace();
429     return aMemSpace == bMemSpace;
430   }
431 
432   return false;
433 }
434 
435 OpFoldResult CastOp::fold(ArrayRef<Attribute> operands) {
436   return succeeded(foldMemRefCast(*this)) ? getResult() : Value();
437 }
438 
439 //===----------------------------------------------------------------------===//
440 // CopyOp
441 //===----------------------------------------------------------------------===//
442 
443 namespace {
444 /// If the source/target of a CopyOp is a CastOp that does not modify the shape
445 /// and element type, the cast can be skipped. Such CastOps only cast the layout
446 /// of the type.
447 struct FoldCopyOfCast : public OpRewritePattern<CopyOp> {
448   using OpRewritePattern<CopyOp>::OpRewritePattern;
449 
450   LogicalResult matchAndRewrite(CopyOp copyOp,
451                                 PatternRewriter &rewriter) const override {
452     bool modified = false;
453 
454     // Check source.
455     if (auto castOp = copyOp.source().getDefiningOp<CastOp>()) {
456       auto fromType = castOp.source().getType().dyn_cast<MemRefType>();
457       auto toType = castOp.source().getType().dyn_cast<MemRefType>();
458 
459       if (fromType && toType) {
460         if (fromType.getShape() == toType.getShape() &&
461             fromType.getElementType() == toType.getElementType()) {
462           rewriter.updateRootInPlace(
463               copyOp, [&] { copyOp.sourceMutable().assign(castOp.source()); });
464           modified = true;
465         }
466       }
467     }
468 
469     // Check target.
470     if (auto castOp = copyOp.target().getDefiningOp<CastOp>()) {
471       auto fromType = castOp.source().getType().dyn_cast<MemRefType>();
472       auto toType = castOp.source().getType().dyn_cast<MemRefType>();
473 
474       if (fromType && toType) {
475         if (fromType.getShape() == toType.getShape() &&
476             fromType.getElementType() == toType.getElementType()) {
477           rewriter.updateRootInPlace(
478               copyOp, [&] { copyOp.targetMutable().assign(castOp.source()); });
479           modified = true;
480         }
481       }
482     }
483 
484     return success(modified);
485   }
486 };
487 
488 /// Fold memref.copy(%x, %x).
489 struct FoldSelfCopy : public OpRewritePattern<CopyOp> {
490   using OpRewritePattern<CopyOp>::OpRewritePattern;
491 
492   LogicalResult matchAndRewrite(CopyOp copyOp,
493                                 PatternRewriter &rewriter) const override {
494     if (copyOp.source() != copyOp.target())
495       return failure();
496 
497     rewriter.eraseOp(copyOp);
498     return success();
499   }
500 };
501 } // namespace
502 
503 void CopyOp::getCanonicalizationPatterns(RewritePatternSet &results,
504                                          MLIRContext *context) {
505   results.add<FoldCopyOfCast, FoldSelfCopy>(context);
506 }
507 
508 LogicalResult CopyOp::fold(ArrayRef<Attribute> cstOperands,
509                            SmallVectorImpl<OpFoldResult> &results) {
510   /// copy(memrefcast) -> copy
511   bool folded = false;
512   Operation *op = *this;
513   for (OpOperand &operand : op->getOpOperands()) {
514     auto castOp = operand.get().getDefiningOp<memref::CastOp>();
515     if (castOp && memref::CastOp::canFoldIntoConsumerOp(castOp)) {
516       operand.set(castOp.getOperand());
517       folded = true;
518     }
519   }
520   return success(folded);
521 }
522 
523 //===----------------------------------------------------------------------===//
524 // DeallocOp
525 //===----------------------------------------------------------------------===//
526 
527 LogicalResult DeallocOp::fold(ArrayRef<Attribute> cstOperands,
528                               SmallVectorImpl<OpFoldResult> &results) {
529   /// dealloc(memrefcast) -> dealloc
530   return foldMemRefCast(*this);
531 }
532 
533 //===----------------------------------------------------------------------===//
534 // DimOp
535 //===----------------------------------------------------------------------===//
536 
537 void DimOp::build(OpBuilder &builder, OperationState &result, Value source,
538                   int64_t index) {
539   auto loc = result.location;
540   Value indexValue = builder.create<arith::ConstantIndexOp>(loc, index);
541   build(builder, result, source, indexValue);
542 }
543 
544 void DimOp::build(OpBuilder &builder, OperationState &result, Value source,
545                   Value index) {
546   auto indexTy = builder.getIndexType();
547   build(builder, result, indexTy, source, index);
548 }
549 
550 Optional<int64_t> DimOp::getConstantIndex() {
551   if (auto constantOp = index().getDefiningOp<arith::ConstantOp>())
552     return constantOp.getValue().cast<IntegerAttr>().getInt();
553   return {};
554 }
555 
556 LogicalResult DimOp::verify() {
557   // Assume unknown index to be in range.
558   Optional<int64_t> index = getConstantIndex();
559   if (!index.hasValue())
560     return success();
561 
562   // Check that constant index is not knowingly out of range.
563   auto type = source().getType();
564   if (auto memrefType = type.dyn_cast<MemRefType>()) {
565     if (index.getValue() >= memrefType.getRank())
566       return emitOpError("index is out of range");
567   } else if (type.isa<UnrankedMemRefType>()) {
568     // Assume index to be in range.
569   } else {
570     llvm_unreachable("expected operand with memref type");
571   }
572   return success();
573 }
574 
575 /// Return a map with key being elements in `vals` and data being number of
576 /// occurences of it. Use std::map, since the `vals` here are strides and the
577 /// dynamic stride value is the same as the tombstone value for
578 /// `DenseMap<int64_t>`.
579 static std::map<int64_t, unsigned> getNumOccurences(ArrayRef<int64_t> vals) {
580   std::map<int64_t, unsigned> numOccurences;
581   for (auto val : vals)
582     numOccurences[val]++;
583   return numOccurences;
584 }
585 
586 /// Given the `originalType` and a `candidateReducedType` whose shape is assumed
587 /// to be a subset of `originalType` with some `1` entries erased, return the
588 /// set of indices that specifies which of the entries of `originalShape` are
589 /// dropped to obtain `reducedShape`.
590 /// This accounts for cases where there are multiple unit-dims, but only a
591 /// subset of those are dropped. For MemRefTypes these can be disambiguated
592 /// using the strides. If a dimension is dropped the stride must be dropped too.
593 static llvm::Optional<llvm::SmallDenseSet<unsigned>>
594 computeMemRefRankReductionMask(MemRefType originalType, MemRefType reducedType,
595                                ArrayRef<OpFoldResult> sizes) {
596   llvm::SmallDenseSet<unsigned> unusedDims;
597   if (originalType.getRank() == reducedType.getRank())
598     return unusedDims;
599 
600   for (const auto &dim : llvm::enumerate(sizes))
601     if (auto attr = dim.value().dyn_cast<Attribute>())
602       if (attr.cast<IntegerAttr>().getInt() == 1)
603         unusedDims.insert(dim.index());
604 
605   SmallVector<int64_t> originalStrides, candidateStrides;
606   int64_t originalOffset, candidateOffset;
607   if (failed(
608           getStridesAndOffset(originalType, originalStrides, originalOffset)) ||
609       failed(
610           getStridesAndOffset(reducedType, candidateStrides, candidateOffset)))
611     return llvm::None;
612 
613   // For memrefs, a dimension is truly dropped if its corresponding stride is
614   // also dropped. This is particularly important when more than one of the dims
615   // is 1. Track the number of occurences of the strides in the original type
616   // and the candidate type. For each unused dim that stride should not be
617   // present in the candidate type. Note that there could be multiple dimensions
618   // that have the same size. We dont need to exactly figure out which dim
619   // corresponds to which stride, we just need to verify that the number of
620   // reptitions of a stride in the original + number of unused dims with that
621   // stride == number of repititions of a stride in the candidate.
622   std::map<int64_t, unsigned> currUnaccountedStrides =
623       getNumOccurences(originalStrides);
624   std::map<int64_t, unsigned> candidateStridesNumOccurences =
625       getNumOccurences(candidateStrides);
626   llvm::SmallDenseSet<unsigned> prunedUnusedDims;
627   for (unsigned dim : unusedDims) {
628     int64_t originalStride = originalStrides[dim];
629     if (currUnaccountedStrides[originalStride] >
630         candidateStridesNumOccurences[originalStride]) {
631       // This dim can be treated as dropped.
632       currUnaccountedStrides[originalStride]--;
633       continue;
634     }
635     if (currUnaccountedStrides[originalStride] ==
636         candidateStridesNumOccurences[originalStride]) {
637       // The stride for this is not dropped. Keep as is.
638       prunedUnusedDims.insert(dim);
639       continue;
640     }
641     if (currUnaccountedStrides[originalStride] <
642         candidateStridesNumOccurences[originalStride]) {
643       // This should never happen. Cant have a stride in the reduced rank type
644       // that wasnt in the original one.
645       return llvm::None;
646     }
647   }
648 
649   for (auto prunedDim : prunedUnusedDims)
650     unusedDims.erase(prunedDim);
651   if (unusedDims.size() + reducedType.getRank() != originalType.getRank())
652     return llvm::None;
653   return unusedDims;
654 }
655 
656 llvm::SmallDenseSet<unsigned> SubViewOp::getDroppedDims() {
657   MemRefType sourceType = getSourceType();
658   MemRefType resultType = getType();
659   llvm::Optional<llvm::SmallDenseSet<unsigned>> unusedDims =
660       computeMemRefRankReductionMask(sourceType, resultType, getMixedSizes());
661   assert(unusedDims && "unable to find unused dims of subview");
662   return *unusedDims;
663 }
664 
665 OpFoldResult DimOp::fold(ArrayRef<Attribute> operands) {
666   // All forms of folding require a known index.
667   auto index = operands[1].dyn_cast_or_null<IntegerAttr>();
668   if (!index)
669     return {};
670 
671   // Folding for unranked types (UnrankedMemRefType) is not supported.
672   auto memrefType = source().getType().dyn_cast<MemRefType>();
673   if (!memrefType)
674     return {};
675 
676   // Fold if the shape extent along the given index is known.
677   if (!memrefType.isDynamicDim(index.getInt())) {
678     Builder builder(getContext());
679     return builder.getIndexAttr(memrefType.getShape()[index.getInt()]);
680   }
681 
682   // The size at the given index is now known to be a dynamic size.
683   unsigned unsignedIndex = index.getValue().getZExtValue();
684 
685   // Fold dim to the size argument for an `AllocOp`, `ViewOp`, or `SubViewOp`.
686   Operation *definingOp = source().getDefiningOp();
687 
688   if (auto alloc = dyn_cast_or_null<AllocOp>(definingOp))
689     return *(alloc.getDynamicSizes().begin() +
690              memrefType.getDynamicDimIndex(unsignedIndex));
691 
692   if (auto alloca = dyn_cast_or_null<AllocaOp>(definingOp))
693     return *(alloca.getDynamicSizes().begin() +
694              memrefType.getDynamicDimIndex(unsignedIndex));
695 
696   if (auto view = dyn_cast_or_null<ViewOp>(definingOp))
697     return *(view.getDynamicSizes().begin() +
698              memrefType.getDynamicDimIndex(unsignedIndex));
699 
700   if (auto subview = dyn_cast_or_null<SubViewOp>(definingOp)) {
701     llvm::SmallDenseSet<unsigned> unusedDims = subview.getDroppedDims();
702     unsigned resultIndex = 0;
703     unsigned sourceRank = subview.getSourceType().getRank();
704     unsigned sourceIndex = 0;
705     for (auto i : llvm::seq<unsigned>(0, sourceRank)) {
706       if (unusedDims.count(i))
707         continue;
708       if (resultIndex == unsignedIndex) {
709         sourceIndex = i;
710         break;
711       }
712       resultIndex++;
713     }
714     assert(subview.isDynamicSize(sourceIndex) &&
715            "expected dynamic subview size");
716     return subview.getDynamicSize(sourceIndex);
717   }
718 
719   if (auto sizeInterface =
720           dyn_cast_or_null<OffsetSizeAndStrideOpInterface>(definingOp)) {
721     assert(sizeInterface.isDynamicSize(unsignedIndex) &&
722            "Expected dynamic subview size");
723     return sizeInterface.getDynamicSize(unsignedIndex);
724   }
725 
726   // dim(memrefcast) -> dim
727   if (succeeded(foldMemRefCast(*this)))
728     return getResult();
729 
730   return {};
731 }
732 
733 namespace {
734 /// Fold dim of a memref reshape operation to a load into the reshape's shape
735 /// operand.
736 struct DimOfMemRefReshape : public OpRewritePattern<DimOp> {
737   using OpRewritePattern<DimOp>::OpRewritePattern;
738 
739   LogicalResult matchAndRewrite(DimOp dim,
740                                 PatternRewriter &rewriter) const override {
741     auto reshape = dim.source().getDefiningOp<ReshapeOp>();
742 
743     if (!reshape)
744       return failure();
745 
746     // Place the load directly after the reshape to ensure that the shape memref
747     // was not mutated.
748     rewriter.setInsertionPointAfter(reshape);
749     Location loc = dim.getLoc();
750     Value load = rewriter.create<LoadOp>(loc, reshape.shape(), dim.index());
751     if (load.getType() != dim.getType())
752       load = rewriter.create<arith::IndexCastOp>(loc, dim.getType(), load);
753     rewriter.replaceOp(dim, load);
754     return success();
755   }
756 };
757 
758 } // namespace
759 
760 void DimOp::getCanonicalizationPatterns(RewritePatternSet &results,
761                                         MLIRContext *context) {
762   results.add<DimOfMemRefReshape>(context);
763 }
764 
765 // ---------------------------------------------------------------------------
766 // DmaStartOp
767 // ---------------------------------------------------------------------------
768 
769 void DmaStartOp::build(OpBuilder &builder, OperationState &result,
770                        Value srcMemRef, ValueRange srcIndices, Value destMemRef,
771                        ValueRange destIndices, Value numElements,
772                        Value tagMemRef, ValueRange tagIndices, Value stride,
773                        Value elementsPerStride) {
774   result.addOperands(srcMemRef);
775   result.addOperands(srcIndices);
776   result.addOperands(destMemRef);
777   result.addOperands(destIndices);
778   result.addOperands({numElements, tagMemRef});
779   result.addOperands(tagIndices);
780   if (stride)
781     result.addOperands({stride, elementsPerStride});
782 }
783 
784 static void print(OpAsmPrinter &p, DmaStartOp op) {
785   p << " " << op.getSrcMemRef() << '[' << op.getSrcIndices() << "], "
786     << op.getDstMemRef() << '[' << op.getDstIndices() << "], "
787     << op.getNumElements() << ", " << op.getTagMemRef() << '['
788     << op.getTagIndices() << ']';
789   if (op.isStrided())
790     p << ", " << op.getStride() << ", " << op.getNumElementsPerStride();
791 
792   p.printOptionalAttrDict(op->getAttrs());
793   p << " : " << op.getSrcMemRef().getType() << ", "
794     << op.getDstMemRef().getType() << ", " << op.getTagMemRef().getType();
795 }
796 
797 // Parse DmaStartOp.
798 // Ex:
799 //   %dma_id = dma_start %src[%i, %j], %dst[%k, %l], %size,
800 //                       %tag[%index], %stride, %num_elt_per_stride :
801 //                     : memref<3076 x f32, 0>,
802 //                       memref<1024 x f32, 2>,
803 //                       memref<1 x i32>
804 //
805 static ParseResult parseDmaStartOp(OpAsmParser &parser,
806                                    OperationState &result) {
807   OpAsmParser::OperandType srcMemRefInfo;
808   SmallVector<OpAsmParser::OperandType, 4> srcIndexInfos;
809   OpAsmParser::OperandType dstMemRefInfo;
810   SmallVector<OpAsmParser::OperandType, 4> dstIndexInfos;
811   OpAsmParser::OperandType numElementsInfo;
812   OpAsmParser::OperandType tagMemrefInfo;
813   SmallVector<OpAsmParser::OperandType, 4> tagIndexInfos;
814   SmallVector<OpAsmParser::OperandType, 2> strideInfo;
815 
816   SmallVector<Type, 3> types;
817   auto indexType = parser.getBuilder().getIndexType();
818 
819   // Parse and resolve the following list of operands:
820   // *) source memref followed by its indices (in square brackets).
821   // *) destination memref followed by its indices (in square brackets).
822   // *) dma size in KiB.
823   if (parser.parseOperand(srcMemRefInfo) ||
824       parser.parseOperandList(srcIndexInfos, OpAsmParser::Delimiter::Square) ||
825       parser.parseComma() || parser.parseOperand(dstMemRefInfo) ||
826       parser.parseOperandList(dstIndexInfos, OpAsmParser::Delimiter::Square) ||
827       parser.parseComma() || parser.parseOperand(numElementsInfo) ||
828       parser.parseComma() || parser.parseOperand(tagMemrefInfo) ||
829       parser.parseOperandList(tagIndexInfos, OpAsmParser::Delimiter::Square))
830     return failure();
831 
832   // Parse optional stride and elements per stride.
833   if (parser.parseTrailingOperandList(strideInfo))
834     return failure();
835 
836   bool isStrided = strideInfo.size() == 2;
837   if (!strideInfo.empty() && !isStrided) {
838     return parser.emitError(parser.getNameLoc(),
839                             "expected two stride related operands");
840   }
841 
842   if (parser.parseColonTypeList(types))
843     return failure();
844   if (types.size() != 3)
845     return parser.emitError(parser.getNameLoc(), "fewer/more types expected");
846 
847   if (parser.resolveOperand(srcMemRefInfo, types[0], result.operands) ||
848       parser.resolveOperands(srcIndexInfos, indexType, result.operands) ||
849       parser.resolveOperand(dstMemRefInfo, types[1], result.operands) ||
850       parser.resolveOperands(dstIndexInfos, indexType, result.operands) ||
851       // size should be an index.
852       parser.resolveOperand(numElementsInfo, indexType, result.operands) ||
853       parser.resolveOperand(tagMemrefInfo, types[2], result.operands) ||
854       // tag indices should be index.
855       parser.resolveOperands(tagIndexInfos, indexType, result.operands))
856     return failure();
857 
858   if (isStrided) {
859     if (parser.resolveOperands(strideInfo, indexType, result.operands))
860       return failure();
861   }
862 
863   return success();
864 }
865 
866 LogicalResult DmaStartOp::verify() {
867   unsigned numOperands = getNumOperands();
868 
869   // Mandatory non-variadic operands are: src memref, dst memref, tag memref and
870   // the number of elements.
871   if (numOperands < 4)
872     return emitOpError("expected at least 4 operands");
873 
874   // Check types of operands. The order of these calls is important: the later
875   // calls rely on some type properties to compute the operand position.
876   // 1. Source memref.
877   if (!getSrcMemRef().getType().isa<MemRefType>())
878     return emitOpError("expected source to be of memref type");
879   if (numOperands < getSrcMemRefRank() + 4)
880     return emitOpError() << "expected at least " << getSrcMemRefRank() + 4
881                          << " operands";
882   if (!getSrcIndices().empty() &&
883       !llvm::all_of(getSrcIndices().getTypes(),
884                     [](Type t) { return t.isIndex(); }))
885     return emitOpError("expected source indices to be of index type");
886 
887   // 2. Destination memref.
888   if (!getDstMemRef().getType().isa<MemRefType>())
889     return emitOpError("expected destination to be of memref type");
890   unsigned numExpectedOperands = getSrcMemRefRank() + getDstMemRefRank() + 4;
891   if (numOperands < numExpectedOperands)
892     return emitOpError() << "expected at least " << numExpectedOperands
893                          << " operands";
894   if (!getDstIndices().empty() &&
895       !llvm::all_of(getDstIndices().getTypes(),
896                     [](Type t) { return t.isIndex(); }))
897     return emitOpError("expected destination indices to be of index type");
898 
899   // 3. Number of elements.
900   if (!getNumElements().getType().isIndex())
901     return emitOpError("expected num elements to be of index type");
902 
903   // 4. Tag memref.
904   if (!getTagMemRef().getType().isa<MemRefType>())
905     return emitOpError("expected tag to be of memref type");
906   numExpectedOperands += getTagMemRefRank();
907   if (numOperands < numExpectedOperands)
908     return emitOpError() << "expected at least " << numExpectedOperands
909                          << " operands";
910   if (!getTagIndices().empty() &&
911       !llvm::all_of(getTagIndices().getTypes(),
912                     [](Type t) { return t.isIndex(); }))
913     return emitOpError("expected tag indices to be of index type");
914 
915   // Optional stride-related operands must be either both present or both
916   // absent.
917   if (numOperands != numExpectedOperands &&
918       numOperands != numExpectedOperands + 2)
919     return emitOpError("incorrect number of operands");
920 
921   // 5. Strides.
922   if (isStrided()) {
923     if (!getStride().getType().isIndex() ||
924         !getNumElementsPerStride().getType().isIndex())
925       return emitOpError(
926           "expected stride and num elements per stride to be of type index");
927   }
928 
929   return success();
930 }
931 
932 LogicalResult DmaStartOp::fold(ArrayRef<Attribute> cstOperands,
933                                SmallVectorImpl<OpFoldResult> &results) {
934   /// dma_start(memrefcast) -> dma_start
935   return foldMemRefCast(*this);
936 }
937 
938 // ---------------------------------------------------------------------------
939 // DmaWaitOp
940 // ---------------------------------------------------------------------------
941 
942 LogicalResult DmaWaitOp::fold(ArrayRef<Attribute> cstOperands,
943                               SmallVectorImpl<OpFoldResult> &results) {
944   /// dma_wait(memrefcast) -> dma_wait
945   return foldMemRefCast(*this);
946 }
947 
948 LogicalResult DmaWaitOp::verify() {
949   // Check that the number of tag indices matches the tagMemRef rank.
950   unsigned numTagIndices = tagIndices().size();
951   unsigned tagMemRefRank = getTagMemRefRank();
952   if (numTagIndices != tagMemRefRank)
953     return emitOpError() << "expected tagIndices to have the same number of "
954                             "elements as the tagMemRef rank, expected "
955                          << tagMemRefRank << ", but got " << numTagIndices;
956   return success();
957 }
958 
959 //===----------------------------------------------------------------------===//
960 // GenericAtomicRMWOp
961 //===----------------------------------------------------------------------===//
962 
963 void GenericAtomicRMWOp::build(OpBuilder &builder, OperationState &result,
964                                Value memref, ValueRange ivs) {
965   result.addOperands(memref);
966   result.addOperands(ivs);
967 
968   if (auto memrefType = memref.getType().dyn_cast<MemRefType>()) {
969     Type elementType = memrefType.getElementType();
970     result.addTypes(elementType);
971 
972     Region *bodyRegion = result.addRegion();
973     bodyRegion->push_back(new Block());
974     bodyRegion->addArgument(elementType, memref.getLoc());
975   }
976 }
977 
978 LogicalResult GenericAtomicRMWOp::verify() {
979   auto &body = getRegion();
980   if (body.getNumArguments() != 1)
981     return emitOpError("expected single number of entry block arguments");
982 
983   if (getResult().getType() != body.getArgument(0).getType())
984     return emitOpError("expected block argument of the same type result type");
985 
986   bool hasSideEffects =
987       body.walk([&](Operation *nestedOp) {
988             if (MemoryEffectOpInterface::hasNoEffect(nestedOp))
989               return WalkResult::advance();
990             nestedOp->emitError(
991                 "body of 'memref.generic_atomic_rmw' should contain "
992                 "only operations with no side effects");
993             return WalkResult::interrupt();
994           })
995           .wasInterrupted();
996   return hasSideEffects ? failure() : success();
997 }
998 
999 static ParseResult parseGenericAtomicRMWOp(OpAsmParser &parser,
1000                                            OperationState &result) {
1001   OpAsmParser::OperandType memref;
1002   Type memrefType;
1003   SmallVector<OpAsmParser::OperandType, 4> ivs;
1004 
1005   Type indexType = parser.getBuilder().getIndexType();
1006   if (parser.parseOperand(memref) ||
1007       parser.parseOperandList(ivs, OpAsmParser::Delimiter::Square) ||
1008       parser.parseColonType(memrefType) ||
1009       parser.resolveOperand(memref, memrefType, result.operands) ||
1010       parser.resolveOperands(ivs, indexType, result.operands))
1011     return failure();
1012 
1013   Region *body = result.addRegion();
1014   if (parser.parseRegion(*body, llvm::None, llvm::None) ||
1015       parser.parseOptionalAttrDict(result.attributes))
1016     return failure();
1017   result.types.push_back(memrefType.cast<MemRefType>().getElementType());
1018   return success();
1019 }
1020 
1021 static void print(OpAsmPrinter &p, GenericAtomicRMWOp op) {
1022   p << ' ' << op.memref() << "[" << op.indices()
1023     << "] : " << op.memref().getType() << ' ';
1024   p.printRegion(op.getRegion());
1025   p.printOptionalAttrDict(op->getAttrs());
1026 }
1027 
1028 //===----------------------------------------------------------------------===//
1029 // AtomicYieldOp
1030 //===----------------------------------------------------------------------===//
1031 
1032 LogicalResult AtomicYieldOp::verify() {
1033   Type parentType = (*this)->getParentOp()->getResultTypes().front();
1034   Type resultType = result().getType();
1035   if (parentType != resultType)
1036     return emitOpError() << "types mismatch between yield op: " << resultType
1037                          << " and its parent: " << parentType;
1038   return success();
1039 }
1040 
1041 //===----------------------------------------------------------------------===//
1042 // GlobalOp
1043 //===----------------------------------------------------------------------===//
1044 
1045 static void printGlobalMemrefOpTypeAndInitialValue(OpAsmPrinter &p, GlobalOp op,
1046                                                    TypeAttr type,
1047                                                    Attribute initialValue) {
1048   p << type;
1049   if (!op.isExternal()) {
1050     p << " = ";
1051     if (op.isUninitialized())
1052       p << "uninitialized";
1053     else
1054       p.printAttributeWithoutType(initialValue);
1055   }
1056 }
1057 
1058 static ParseResult
1059 parseGlobalMemrefOpTypeAndInitialValue(OpAsmParser &parser, TypeAttr &typeAttr,
1060                                        Attribute &initialValue) {
1061   Type type;
1062   if (parser.parseType(type))
1063     return failure();
1064 
1065   auto memrefType = type.dyn_cast<MemRefType>();
1066   if (!memrefType || !memrefType.hasStaticShape())
1067     return parser.emitError(parser.getNameLoc())
1068            << "type should be static shaped memref, but got " << type;
1069   typeAttr = TypeAttr::get(type);
1070 
1071   if (parser.parseOptionalEqual())
1072     return success();
1073 
1074   if (succeeded(parser.parseOptionalKeyword("uninitialized"))) {
1075     initialValue = UnitAttr::get(parser.getContext());
1076     return success();
1077   }
1078 
1079   Type tensorType = getTensorTypeFromMemRefType(memrefType);
1080   if (parser.parseAttribute(initialValue, tensorType))
1081     return failure();
1082   if (!initialValue.isa<ElementsAttr>())
1083     return parser.emitError(parser.getNameLoc())
1084            << "initial value should be a unit or elements attribute";
1085   return success();
1086 }
1087 
1088 LogicalResult GlobalOp::verify() {
1089   auto memrefType = type().dyn_cast<MemRefType>();
1090   if (!memrefType || !memrefType.hasStaticShape())
1091     return emitOpError("type should be static shaped memref, but got ")
1092            << type();
1093 
1094   // Verify that the initial value, if present, is either a unit attribute or
1095   // an elements attribute.
1096   if (initial_value().hasValue()) {
1097     Attribute initValue = initial_value().getValue();
1098     if (!initValue.isa<UnitAttr>() && !initValue.isa<ElementsAttr>())
1099       return emitOpError("initial value should be a unit or elements "
1100                          "attribute, but got ")
1101              << initValue;
1102 
1103     // Check that the type of the initial value is compatible with the type of
1104     // the global variable.
1105     if (initValue.isa<ElementsAttr>()) {
1106       Type initType = initValue.getType();
1107       Type tensorType = getTensorTypeFromMemRefType(memrefType);
1108       if (initType != tensorType)
1109         return emitOpError("initial value expected to be of type ")
1110                << tensorType << ", but was of type " << initType;
1111     }
1112   }
1113 
1114   if (Optional<uint64_t> alignAttr = alignment()) {
1115     uint64_t alignment = alignAttr.getValue();
1116 
1117     if (!llvm::isPowerOf2_64(alignment))
1118       return emitError() << "alignment attribute value " << alignment
1119                          << " is not a power of 2";
1120   }
1121 
1122   // TODO: verify visibility for declarations.
1123   return success();
1124 }
1125 
1126 //===----------------------------------------------------------------------===//
1127 // GetGlobalOp
1128 //===----------------------------------------------------------------------===//
1129 
1130 LogicalResult
1131 GetGlobalOp::verifySymbolUses(SymbolTableCollection &symbolTable) {
1132   // Verify that the result type is same as the type of the referenced
1133   // memref.global op.
1134   auto global =
1135       symbolTable.lookupNearestSymbolFrom<GlobalOp>(*this, nameAttr());
1136   if (!global)
1137     return emitOpError("'")
1138            << name() << "' does not reference a valid global memref";
1139 
1140   Type resultType = result().getType();
1141   if (global.type() != resultType)
1142     return emitOpError("result type ")
1143            << resultType << " does not match type " << global.type()
1144            << " of the global memref @" << name();
1145   return success();
1146 }
1147 
1148 //===----------------------------------------------------------------------===//
1149 // LoadOp
1150 //===----------------------------------------------------------------------===//
1151 
1152 LogicalResult LoadOp::verify() {
1153   if (getNumOperands() != 1 + getMemRefType().getRank())
1154     return emitOpError("incorrect number of indices for load");
1155   return success();
1156 }
1157 
1158 OpFoldResult LoadOp::fold(ArrayRef<Attribute> cstOperands) {
1159   /// load(memrefcast) -> load
1160   if (succeeded(foldMemRefCast(*this)))
1161     return getResult();
1162   return OpFoldResult();
1163 }
1164 
1165 //===----------------------------------------------------------------------===//
1166 // PrefetchOp
1167 //===----------------------------------------------------------------------===//
1168 
1169 static void print(OpAsmPrinter &p, PrefetchOp op) {
1170   p << " " << op.memref() << '[';
1171   p.printOperands(op.indices());
1172   p << ']' << ", " << (op.isWrite() ? "write" : "read");
1173   p << ", locality<" << op.localityHint();
1174   p << ">, " << (op.isDataCache() ? "data" : "instr");
1175   p.printOptionalAttrDict(
1176       op->getAttrs(),
1177       /*elidedAttrs=*/{"localityHint", "isWrite", "isDataCache"});
1178   p << " : " << op.getMemRefType();
1179 }
1180 
1181 static ParseResult parsePrefetchOp(OpAsmParser &parser,
1182                                    OperationState &result) {
1183   OpAsmParser::OperandType memrefInfo;
1184   SmallVector<OpAsmParser::OperandType, 4> indexInfo;
1185   IntegerAttr localityHint;
1186   MemRefType type;
1187   StringRef readOrWrite, cacheType;
1188 
1189   auto indexTy = parser.getBuilder().getIndexType();
1190   auto i32Type = parser.getBuilder().getIntegerType(32);
1191   if (parser.parseOperand(memrefInfo) ||
1192       parser.parseOperandList(indexInfo, OpAsmParser::Delimiter::Square) ||
1193       parser.parseComma() || parser.parseKeyword(&readOrWrite) ||
1194       parser.parseComma() || parser.parseKeyword("locality") ||
1195       parser.parseLess() ||
1196       parser.parseAttribute(localityHint, i32Type, "localityHint",
1197                             result.attributes) ||
1198       parser.parseGreater() || parser.parseComma() ||
1199       parser.parseKeyword(&cacheType) || parser.parseColonType(type) ||
1200       parser.resolveOperand(memrefInfo, type, result.operands) ||
1201       parser.resolveOperands(indexInfo, indexTy, result.operands))
1202     return failure();
1203 
1204   if (!readOrWrite.equals("read") && !readOrWrite.equals("write"))
1205     return parser.emitError(parser.getNameLoc(),
1206                             "rw specifier has to be 'read' or 'write'");
1207   result.addAttribute(
1208       PrefetchOp::getIsWriteAttrName(),
1209       parser.getBuilder().getBoolAttr(readOrWrite.equals("write")));
1210 
1211   if (!cacheType.equals("data") && !cacheType.equals("instr"))
1212     return parser.emitError(parser.getNameLoc(),
1213                             "cache type has to be 'data' or 'instr'");
1214 
1215   result.addAttribute(
1216       PrefetchOp::getIsDataCacheAttrName(),
1217       parser.getBuilder().getBoolAttr(cacheType.equals("data")));
1218 
1219   return success();
1220 }
1221 
1222 LogicalResult PrefetchOp::verify() {
1223   if (getNumOperands() != 1 + getMemRefType().getRank())
1224     return emitOpError("too few indices");
1225 
1226   return success();
1227 }
1228 
1229 LogicalResult PrefetchOp::fold(ArrayRef<Attribute> cstOperands,
1230                                SmallVectorImpl<OpFoldResult> &results) {
1231   // prefetch(memrefcast) -> prefetch
1232   return foldMemRefCast(*this);
1233 }
1234 
1235 //===----------------------------------------------------------------------===//
1236 // RankOp
1237 //===----------------------------------------------------------------------===//
1238 
1239 OpFoldResult RankOp::fold(ArrayRef<Attribute> operands) {
1240   // Constant fold rank when the rank of the operand is known.
1241   auto type = getOperand().getType();
1242   auto shapedType = type.dyn_cast<ShapedType>();
1243   if (shapedType && shapedType.hasRank())
1244     return IntegerAttr::get(IndexType::get(getContext()), shapedType.getRank());
1245   return IntegerAttr();
1246 }
1247 
1248 //===----------------------------------------------------------------------===//
1249 // ReinterpretCastOp
1250 //===----------------------------------------------------------------------===//
1251 
1252 /// Build a ReinterpretCastOp with all dynamic entries: `staticOffsets`,
1253 /// `staticSizes` and `staticStrides` are automatically filled with
1254 /// source-memref-rank sentinel values that encode dynamic entries.
1255 void ReinterpretCastOp::build(OpBuilder &b, OperationState &result,
1256                               MemRefType resultType, Value source,
1257                               OpFoldResult offset, ArrayRef<OpFoldResult> sizes,
1258                               ArrayRef<OpFoldResult> strides,
1259                               ArrayRef<NamedAttribute> attrs) {
1260   SmallVector<int64_t> staticOffsets, staticSizes, staticStrides;
1261   SmallVector<Value> dynamicOffsets, dynamicSizes, dynamicStrides;
1262   dispatchIndexOpFoldResults(offset, dynamicOffsets, staticOffsets,
1263                              ShapedType::kDynamicStrideOrOffset);
1264   dispatchIndexOpFoldResults(sizes, dynamicSizes, staticSizes,
1265                              ShapedType::kDynamicSize);
1266   dispatchIndexOpFoldResults(strides, dynamicStrides, staticStrides,
1267                              ShapedType::kDynamicStrideOrOffset);
1268   build(b, result, resultType, source, dynamicOffsets, dynamicSizes,
1269         dynamicStrides, b.getI64ArrayAttr(staticOffsets),
1270         b.getI64ArrayAttr(staticSizes), b.getI64ArrayAttr(staticStrides));
1271   result.addAttributes(attrs);
1272 }
1273 
1274 void ReinterpretCastOp::build(OpBuilder &b, OperationState &result,
1275                               MemRefType resultType, Value source,
1276                               int64_t offset, ArrayRef<int64_t> sizes,
1277                               ArrayRef<int64_t> strides,
1278                               ArrayRef<NamedAttribute> attrs) {
1279   SmallVector<OpFoldResult> sizeValues =
1280       llvm::to_vector<4>(llvm::map_range(sizes, [&](int64_t v) -> OpFoldResult {
1281         return b.getI64IntegerAttr(v);
1282       }));
1283   SmallVector<OpFoldResult> strideValues = llvm::to_vector<4>(
1284       llvm::map_range(strides, [&](int64_t v) -> OpFoldResult {
1285         return b.getI64IntegerAttr(v);
1286       }));
1287   build(b, result, resultType, source, b.getI64IntegerAttr(offset), sizeValues,
1288         strideValues, attrs);
1289 }
1290 
1291 void ReinterpretCastOp::build(OpBuilder &b, OperationState &result,
1292                               MemRefType resultType, Value source, Value offset,
1293                               ValueRange sizes, ValueRange strides,
1294                               ArrayRef<NamedAttribute> attrs) {
1295   SmallVector<OpFoldResult> sizeValues = llvm::to_vector<4>(
1296       llvm::map_range(sizes, [](Value v) -> OpFoldResult { return v; }));
1297   SmallVector<OpFoldResult> strideValues = llvm::to_vector<4>(
1298       llvm::map_range(strides, [](Value v) -> OpFoldResult { return v; }));
1299   build(b, result, resultType, source, offset, sizeValues, strideValues, attrs);
1300 }
1301 
1302 // TODO: ponder whether we want to allow missing trailing sizes/strides that are
1303 // completed automatically, like we have for subview and extract_slice.
1304 LogicalResult ReinterpretCastOp::verify() {
1305   // The source and result memrefs should be in the same memory space.
1306   auto srcType = source().getType().cast<BaseMemRefType>();
1307   auto resultType = getType().cast<MemRefType>();
1308   if (srcType.getMemorySpace() != resultType.getMemorySpace())
1309     return emitError("different memory spaces specified for source type ")
1310            << srcType << " and result memref type " << resultType;
1311   if (srcType.getElementType() != resultType.getElementType())
1312     return emitError("different element types specified for source type ")
1313            << srcType << " and result memref type " << resultType;
1314 
1315   // Match sizes in result memref type and in static_sizes attribute.
1316   for (auto &en : llvm::enumerate(llvm::zip(
1317            resultType.getShape(), extractFromI64ArrayAttr(static_sizes())))) {
1318     int64_t resultSize = std::get<0>(en.value());
1319     int64_t expectedSize = std::get<1>(en.value());
1320     if (!ShapedType::isDynamic(resultSize) &&
1321         !ShapedType::isDynamic(expectedSize) && resultSize != expectedSize)
1322       return emitError("expected result type with size = ")
1323              << expectedSize << " instead of " << resultSize
1324              << " in dim = " << en.index();
1325   }
1326 
1327   // Match offset and strides in static_offset and static_strides attributes. If
1328   // result memref type has no affine map specified, this will assume an
1329   // identity layout.
1330   int64_t resultOffset;
1331   SmallVector<int64_t, 4> resultStrides;
1332   if (failed(getStridesAndOffset(resultType, resultStrides, resultOffset)))
1333     return emitError("expected result type to have strided layout but found ")
1334            << resultType;
1335 
1336   // Match offset in result memref type and in static_offsets attribute.
1337   int64_t expectedOffset = extractFromI64ArrayAttr(static_offsets()).front();
1338   if (!ShapedType::isDynamicStrideOrOffset(resultOffset) &&
1339       !ShapedType::isDynamicStrideOrOffset(expectedOffset) &&
1340       resultOffset != expectedOffset)
1341     return emitError("expected result type with offset = ")
1342            << resultOffset << " instead of " << expectedOffset;
1343 
1344   // Match strides in result memref type and in static_strides attribute.
1345   for (auto &en : llvm::enumerate(llvm::zip(
1346            resultStrides, extractFromI64ArrayAttr(static_strides())))) {
1347     int64_t resultStride = std::get<0>(en.value());
1348     int64_t expectedStride = std::get<1>(en.value());
1349     if (!ShapedType::isDynamicStrideOrOffset(resultStride) &&
1350         !ShapedType::isDynamicStrideOrOffset(expectedStride) &&
1351         resultStride != expectedStride)
1352       return emitError("expected result type with stride = ")
1353              << expectedStride << " instead of " << resultStride
1354              << " in dim = " << en.index();
1355   }
1356 
1357   return success();
1358 }
1359 
1360 //===----------------------------------------------------------------------===//
1361 // Reassociative reshape ops
1362 //===----------------------------------------------------------------------===//
1363 
1364 SmallVector<AffineMap, 4> CollapseShapeOp::getReassociationMaps() {
1365   return getSymbolLessAffineMaps(getReassociationExprs());
1366 }
1367 SmallVector<ReassociationExprs, 4> CollapseShapeOp::getReassociationExprs() {
1368   return convertReassociationIndicesToExprs(getContext(),
1369                                             getReassociationIndices());
1370 }
1371 
1372 SmallVector<AffineMap, 4> ExpandShapeOp::getReassociationMaps() {
1373   return getSymbolLessAffineMaps(getReassociationExprs());
1374 }
1375 SmallVector<ReassociationExprs, 4> ExpandShapeOp::getReassociationExprs() {
1376   return convertReassociationIndicesToExprs(getContext(),
1377                                             getReassociationIndices());
1378 }
1379 
1380 static void print(OpAsmPrinter &p, ExpandShapeOp op) {
1381   ::mlir::printReshapeOp<ExpandShapeOp>(p, op);
1382 }
1383 
1384 static void print(OpAsmPrinter &p, CollapseShapeOp op) {
1385   ::mlir::printReshapeOp<CollapseShapeOp>(p, op);
1386 }
1387 
1388 /// Detect whether memref dims [dim, dim + extent) can be reshaped without
1389 /// copies.
1390 static bool isReshapableDimBand(unsigned dim, unsigned extent,
1391                                 ArrayRef<int64_t> sizes,
1392                                 ArrayRef<AffineExpr> strides) {
1393   // Bands of extent one can be reshaped, as they are not reshaped at all.
1394   if (extent == 1)
1395     return true;
1396   // Otherwise, the size of the first dimension needs to be known.
1397   if (ShapedType::isDynamic(sizes[dim]))
1398     return false;
1399   assert(sizes.size() == strides.size() && "mismatched ranks");
1400   // off by 1 indexing to avoid out of bounds
1401   //                       V
1402   for (auto idx = dim, e = dim + extent; idx + 1 < e; ++idx) {
1403     // Only bands of static shapes are reshapable. This is due to the fact that
1404     // there is no relation between dynamic sizes and dynamic strides: we do not
1405     // have enough information to know whether a "-1" size corresponds to the
1406     // proper symbol in the AffineExpr of a stride.
1407     if (ShapedType::isDynamic(sizes[idx + 1]))
1408       return false;
1409     // TODO: Refine this by passing the proper nDims and nSymbols so we can
1410     // simplify on the fly and catch more reshapable cases.
1411     if (strides[idx] != strides[idx + 1] * sizes[idx + 1])
1412       return false;
1413   }
1414   return true;
1415 }
1416 
1417 /// Compute the MemRefType obtained by applying the `reassociation` (which is
1418 /// expected to be valid) to `type`.
1419 /// If `type` is Contiguous MemRefType, this always produce a contiguous
1420 /// MemRefType.
1421 static MemRefType
1422 computeReshapeCollapsedType(MemRefType type,
1423                             ArrayRef<AffineMap> reassociation) {
1424   auto sizes = type.getShape();
1425   AffineExpr offset;
1426   SmallVector<AffineExpr, 4> strides;
1427   auto status = getStridesAndOffset(type, strides, offset);
1428   auto isIdentityLayout = type.getLayout().isIdentity();
1429   (void)status;
1430   assert(succeeded(status) && "expected strided memref");
1431 
1432   SmallVector<int64_t, 4> newSizes;
1433   newSizes.reserve(reassociation.size());
1434   SmallVector<AffineExpr, 4> newStrides;
1435   newStrides.reserve(reassociation.size());
1436 
1437   // Use the fact that reassociation is valid to simplify the logic: only use
1438   // each map's rank.
1439   assert(isReassociationValid(reassociation) && "invalid reassociation");
1440   unsigned currentDim = 0;
1441   for (AffineMap m : reassociation) {
1442     unsigned dim = m.getNumResults();
1443     int64_t size = 1;
1444     AffineExpr stride = strides[currentDim + dim - 1];
1445     if (isIdentityLayout ||
1446         isReshapableDimBand(currentDim, dim, sizes, strides)) {
1447       for (unsigned d = 0; d < dim; ++d) {
1448         int64_t currentSize = sizes[currentDim + d];
1449         if (ShapedType::isDynamic(currentSize)) {
1450           size = ShapedType::kDynamicSize;
1451           break;
1452         }
1453         size *= currentSize;
1454       }
1455     } else {
1456       size = ShapedType::kDynamicSize;
1457       stride = AffineExpr();
1458     }
1459     newSizes.push_back(size);
1460     newStrides.push_back(stride);
1461     currentDim += dim;
1462   }
1463 
1464   // Early-exit: if `type` is contiguous, the result must be contiguous.
1465   if (canonicalizeStridedLayout(type).getLayout().isIdentity())
1466     return MemRefType::Builder(type).setShape(newSizes).setLayout({});
1467 
1468   // Convert back to int64_t because we don't have enough information to create
1469   // new strided layouts from AffineExpr only. This corresponds to a case where
1470   // copies may be necessary.
1471   int64_t intOffset = ShapedType::kDynamicStrideOrOffset;
1472   if (auto o = offset.dyn_cast<AffineConstantExpr>())
1473     intOffset = o.getValue();
1474   SmallVector<int64_t, 4> intStrides;
1475   intStrides.reserve(strides.size());
1476   for (auto stride : newStrides) {
1477     if (auto cst = stride.dyn_cast_or_null<AffineConstantExpr>())
1478       intStrides.push_back(cst.getValue());
1479     else
1480       intStrides.push_back(ShapedType::kDynamicStrideOrOffset);
1481   }
1482   auto layout =
1483       makeStridedLinearLayoutMap(intStrides, intOffset, type.getContext());
1484   return canonicalizeStridedLayout(
1485       MemRefType::Builder(type).setShape(newSizes).setLayout(
1486           AffineMapAttr::get(layout)));
1487 }
1488 
1489 void ExpandShapeOp::build(OpBuilder &b, OperationState &result, Value src,
1490                           ArrayRef<ReassociationIndices> reassociation,
1491                           ArrayRef<NamedAttribute> attrs) {
1492   auto memRefType = src.getType().cast<MemRefType>();
1493   auto resultType = computeReshapeCollapsedType(
1494       memRefType, getSymbolLessAffineMaps(convertReassociationIndicesToExprs(
1495                       b.getContext(), reassociation)));
1496   build(b, result, resultType, src, attrs);
1497   result.addAttribute(getReassociationAttrName(),
1498                       getReassociationIndicesAttribute(b, reassociation));
1499 }
1500 
1501 void CollapseShapeOp::build(OpBuilder &b, OperationState &result, Value src,
1502                             ArrayRef<ReassociationIndices> reassociation,
1503                             ArrayRef<NamedAttribute> attrs) {
1504   auto memRefType = src.getType().cast<MemRefType>();
1505   auto resultType = computeReshapeCollapsedType(
1506       memRefType, getSymbolLessAffineMaps(convertReassociationIndicesToExprs(
1507                       b.getContext(), reassociation)));
1508   build(b, result, resultType, src, attrs);
1509   result.addAttribute(getReassociationAttrName(),
1510                       getReassociationIndicesAttribute(b, reassociation));
1511 }
1512 
1513 template <typename ReshapeOp,
1514           bool isExpansion = std::is_same<ReshapeOp, ExpandShapeOp>::value>
1515 static LogicalResult verifyReshapeOp(ReshapeOp op, MemRefType expandedType,
1516                                      MemRefType collapsedType) {
1517   if (failed(
1518           verifyReshapeLikeTypes(op, expandedType, collapsedType, isExpansion)))
1519     return failure();
1520   auto maps = op.getReassociationMaps();
1521   MemRefType expectedType = computeReshapeCollapsedType(expandedType, maps);
1522   if (collapsedType != expectedType)
1523     return op.emitOpError("expected collapsed type to be ")
1524            << expectedType << ", but got " << collapsedType;
1525   return success();
1526 }
1527 
1528 LogicalResult ExpandShapeOp::verify() {
1529   return verifyReshapeOp(*this, getResultType(), getSrcType());
1530 }
1531 
1532 void ExpandShapeOp::getCanonicalizationPatterns(RewritePatternSet &results,
1533                                                 MLIRContext *context) {
1534   results.add<CollapseReshapeOps<ExpandShapeOp>,
1535               CollapseMixedReshapeOps<ExpandShapeOp, CollapseShapeOp>>(context);
1536 }
1537 
1538 LogicalResult CollapseShapeOp::verify() {
1539   return verifyReshapeOp(*this, getSrcType(), getResultType());
1540 }
1541 
1542 struct CollapseShapeOpMemRefCastFolder
1543     : public OpRewritePattern<CollapseShapeOp> {
1544 public:
1545   using OpRewritePattern<CollapseShapeOp>::OpRewritePattern;
1546 
1547   LogicalResult matchAndRewrite(CollapseShapeOp op,
1548                                 PatternRewriter &rewriter) const override {
1549     auto cast = op.getOperand().getDefiningOp<CastOp>();
1550     if (!cast)
1551       return failure();
1552 
1553     if (!CastOp::canFoldIntoConsumerOp(cast))
1554       return failure();
1555 
1556     Type newResultType = computeReshapeCollapsedType(
1557         cast.getOperand().getType().cast<MemRefType>(),
1558         op.getReassociationMaps());
1559 
1560     if (newResultType == op.getResultType()) {
1561       rewriter.updateRootInPlace(
1562           op, [&]() { op.srcMutable().assign(cast.source()); });
1563     } else {
1564       Value newOp = rewriter.create<CollapseShapeOp>(
1565           op->getLoc(), cast.source(), op.getReassociationIndices());
1566       rewriter.replaceOpWithNewOp<CastOp>(op, op.getType(), newOp);
1567     }
1568     return success();
1569   }
1570 };
1571 
1572 void CollapseShapeOp::getCanonicalizationPatterns(RewritePatternSet &results,
1573                                                   MLIRContext *context) {
1574   results.add<CollapseReshapeOps<CollapseShapeOp>,
1575               CollapseMixedReshapeOps<CollapseShapeOp, ExpandShapeOp>,
1576               CollapseShapeOpMemRefCastFolder>(context);
1577 }
1578 OpFoldResult ExpandShapeOp::fold(ArrayRef<Attribute> operands) {
1579   return foldReshapeOp<ExpandShapeOp, CollapseShapeOp>(*this, operands);
1580 }
1581 OpFoldResult CollapseShapeOp::fold(ArrayRef<Attribute> operands) {
1582   return foldReshapeOp<CollapseShapeOp, ExpandShapeOp>(*this, operands);
1583 }
1584 
1585 //===----------------------------------------------------------------------===//
1586 // ReshapeOp
1587 //===----------------------------------------------------------------------===//
1588 
1589 LogicalResult ReshapeOp::verify() {
1590   Type operandType = source().getType();
1591   Type resultType = result().getType();
1592 
1593   Type operandElementType = operandType.cast<ShapedType>().getElementType();
1594   Type resultElementType = resultType.cast<ShapedType>().getElementType();
1595   if (operandElementType != resultElementType)
1596     return emitOpError("element types of source and destination memref "
1597                        "types should be the same");
1598 
1599   if (auto operandMemRefType = operandType.dyn_cast<MemRefType>())
1600     if (!operandMemRefType.getLayout().isIdentity())
1601       return emitOpError("source memref type should have identity affine map");
1602 
1603   int64_t shapeSize = shape().getType().cast<MemRefType>().getDimSize(0);
1604   auto resultMemRefType = resultType.dyn_cast<MemRefType>();
1605   if (resultMemRefType) {
1606     if (!resultMemRefType.getLayout().isIdentity())
1607       return emitOpError("result memref type should have identity affine map");
1608     if (shapeSize == ShapedType::kDynamicSize)
1609       return emitOpError("cannot use shape operand with dynamic length to "
1610                          "reshape to statically-ranked memref type");
1611     if (shapeSize != resultMemRefType.getRank())
1612       return emitOpError(
1613           "length of shape operand differs from the result's memref rank");
1614   }
1615   return success();
1616 }
1617 
1618 //===----------------------------------------------------------------------===//
1619 // StoreOp
1620 //===----------------------------------------------------------------------===//
1621 
1622 LogicalResult StoreOp::verify() {
1623   if (getNumOperands() != 2 + getMemRefType().getRank())
1624     return emitOpError("store index operand count not equal to memref rank");
1625 
1626   return success();
1627 }
1628 
1629 LogicalResult StoreOp::fold(ArrayRef<Attribute> cstOperands,
1630                             SmallVectorImpl<OpFoldResult> &results) {
1631   /// store(memrefcast) -> store
1632   return foldMemRefCast(*this, getValueToStore());
1633 }
1634 
1635 //===----------------------------------------------------------------------===//
1636 // SubViewOp
1637 //===----------------------------------------------------------------------===//
1638 
1639 namespace {
1640 /// Helpers to write more idiomatic operations.
1641 namespace saturated_arith {
1642 struct Wrapper {
1643   explicit Wrapper(int64_t v) : v(v) {}
1644   operator int64_t() { return v; }
1645   int64_t v;
1646 };
1647 Wrapper operator+(Wrapper a, int64_t b) {
1648   if (ShapedType::isDynamicStrideOrOffset(a) ||
1649       ShapedType::isDynamicStrideOrOffset(b))
1650     return Wrapper(ShapedType::kDynamicStrideOrOffset);
1651   return Wrapper(a.v + b);
1652 }
1653 Wrapper operator*(Wrapper a, int64_t b) {
1654   if (ShapedType::isDynamicStrideOrOffset(a) ||
1655       ShapedType::isDynamicStrideOrOffset(b))
1656     return Wrapper(ShapedType::kDynamicStrideOrOffset);
1657   return Wrapper(a.v * b);
1658 }
1659 } // namespace saturated_arith
1660 } // namespace
1661 
1662 /// A subview result type can be fully inferred from the source type and the
1663 /// static representation of offsets, sizes and strides. Special sentinels
1664 /// encode the dynamic case.
1665 Type SubViewOp::inferResultType(MemRefType sourceMemRefType,
1666                                 ArrayRef<int64_t> staticOffsets,
1667                                 ArrayRef<int64_t> staticSizes,
1668                                 ArrayRef<int64_t> staticStrides) {
1669   unsigned rank = sourceMemRefType.getRank();
1670   (void)rank;
1671   assert(staticOffsets.size() == rank && "staticOffsets length mismatch");
1672   assert(staticSizes.size() == rank && "staticSizes length mismatch");
1673   assert(staticStrides.size() == rank && "staticStrides length mismatch");
1674 
1675   // Extract source offset and strides.
1676   int64_t sourceOffset;
1677   SmallVector<int64_t, 4> sourceStrides;
1678   auto res = getStridesAndOffset(sourceMemRefType, sourceStrides, sourceOffset);
1679   assert(succeeded(res) && "SubViewOp expected strided memref type");
1680   (void)res;
1681 
1682   // Compute target offset whose value is:
1683   //   `sourceOffset + sum_i(staticOffset_i * sourceStrides_i)`.
1684   int64_t targetOffset = sourceOffset;
1685   for (auto it : llvm::zip(staticOffsets, sourceStrides)) {
1686     auto staticOffset = std::get<0>(it), targetStride = std::get<1>(it);
1687     using namespace saturated_arith;
1688     targetOffset = Wrapper(targetOffset) + Wrapper(staticOffset) * targetStride;
1689   }
1690 
1691   // Compute target stride whose value is:
1692   //   `sourceStrides_i * staticStrides_i`.
1693   SmallVector<int64_t, 4> targetStrides;
1694   targetStrides.reserve(staticOffsets.size());
1695   for (auto it : llvm::zip(sourceStrides, staticStrides)) {
1696     auto sourceStride = std::get<0>(it), staticStride = std::get<1>(it);
1697     using namespace saturated_arith;
1698     targetStrides.push_back(Wrapper(sourceStride) * staticStride);
1699   }
1700 
1701   // The type is now known.
1702   return MemRefType::get(
1703       staticSizes, sourceMemRefType.getElementType(),
1704       makeStridedLinearLayoutMap(targetStrides, targetOffset,
1705                                  sourceMemRefType.getContext()),
1706       sourceMemRefType.getMemorySpace());
1707 }
1708 
1709 Type SubViewOp::inferResultType(MemRefType sourceMemRefType,
1710                                 ArrayRef<OpFoldResult> offsets,
1711                                 ArrayRef<OpFoldResult> sizes,
1712                                 ArrayRef<OpFoldResult> strides) {
1713   SmallVector<int64_t> staticOffsets, staticSizes, staticStrides;
1714   SmallVector<Value> dynamicOffsets, dynamicSizes, dynamicStrides;
1715   dispatchIndexOpFoldResults(offsets, dynamicOffsets, staticOffsets,
1716                              ShapedType::kDynamicStrideOrOffset);
1717   dispatchIndexOpFoldResults(sizes, dynamicSizes, staticSizes,
1718                              ShapedType::kDynamicSize);
1719   dispatchIndexOpFoldResults(strides, dynamicStrides, staticStrides,
1720                              ShapedType::kDynamicStrideOrOffset);
1721   return SubViewOp::inferResultType(sourceMemRefType, staticOffsets,
1722                                     staticSizes, staticStrides);
1723 }
1724 
1725 Type SubViewOp::inferRankReducedResultType(unsigned resultRank,
1726                                            MemRefType sourceRankedTensorType,
1727                                            ArrayRef<int64_t> offsets,
1728                                            ArrayRef<int64_t> sizes,
1729                                            ArrayRef<int64_t> strides) {
1730   auto inferredType =
1731       inferResultType(sourceRankedTensorType, offsets, sizes, strides)
1732           .cast<MemRefType>();
1733   assert(inferredType.getRank() >= resultRank && "expected ");
1734   int rankDiff = inferredType.getRank() - resultRank;
1735   if (rankDiff > 0) {
1736     auto shape = inferredType.getShape();
1737     llvm::SmallDenseSet<unsigned> dimsToProject;
1738     mlir::getPositionsOfShapeOne(rankDiff, shape, dimsToProject);
1739     SmallVector<int64_t> projectedShape;
1740     for (unsigned pos = 0, e = shape.size(); pos < e; ++pos)
1741       if (!dimsToProject.contains(pos))
1742         projectedShape.push_back(shape[pos]);
1743 
1744     AffineMap map = inferredType.getLayout().getAffineMap();
1745     if (!map.isIdentity())
1746       map = getProjectedMap(map, dimsToProject);
1747     inferredType =
1748         MemRefType::get(projectedShape, inferredType.getElementType(), map,
1749                         inferredType.getMemorySpace());
1750   }
1751   return inferredType;
1752 }
1753 
1754 Type SubViewOp::inferRankReducedResultType(unsigned resultRank,
1755                                            MemRefType sourceRankedTensorType,
1756                                            ArrayRef<OpFoldResult> offsets,
1757                                            ArrayRef<OpFoldResult> sizes,
1758                                            ArrayRef<OpFoldResult> strides) {
1759   SmallVector<int64_t> staticOffsets, staticSizes, staticStrides;
1760   SmallVector<Value> dynamicOffsets, dynamicSizes, dynamicStrides;
1761   dispatchIndexOpFoldResults(offsets, dynamicOffsets, staticOffsets,
1762                              ShapedType::kDynamicStrideOrOffset);
1763   dispatchIndexOpFoldResults(sizes, dynamicSizes, staticSizes,
1764                              ShapedType::kDynamicSize);
1765   dispatchIndexOpFoldResults(strides, dynamicStrides, staticStrides,
1766                              ShapedType::kDynamicStrideOrOffset);
1767   return SubViewOp::inferRankReducedResultType(
1768       resultRank, sourceRankedTensorType, staticOffsets, staticSizes,
1769       staticStrides);
1770 }
1771 // Build a SubViewOp with mixed static and dynamic entries and custom result
1772 // type. If the type passed is nullptr, it is inferred.
1773 void SubViewOp::build(OpBuilder &b, OperationState &result,
1774                       MemRefType resultType, Value source,
1775                       ArrayRef<OpFoldResult> offsets,
1776                       ArrayRef<OpFoldResult> sizes,
1777                       ArrayRef<OpFoldResult> strides,
1778                       ArrayRef<NamedAttribute> attrs) {
1779   SmallVector<int64_t> staticOffsets, staticSizes, staticStrides;
1780   SmallVector<Value> dynamicOffsets, dynamicSizes, dynamicStrides;
1781   dispatchIndexOpFoldResults(offsets, dynamicOffsets, staticOffsets,
1782                              ShapedType::kDynamicStrideOrOffset);
1783   dispatchIndexOpFoldResults(sizes, dynamicSizes, staticSizes,
1784                              ShapedType::kDynamicSize);
1785   dispatchIndexOpFoldResults(strides, dynamicStrides, staticStrides,
1786                              ShapedType::kDynamicStrideOrOffset);
1787   auto sourceMemRefType = source.getType().cast<MemRefType>();
1788   // Structuring implementation this way avoids duplication between builders.
1789   if (!resultType) {
1790     resultType = SubViewOp::inferResultType(sourceMemRefType, staticOffsets,
1791                                             staticSizes, staticStrides)
1792                      .cast<MemRefType>();
1793   }
1794   build(b, result, resultType, source, dynamicOffsets, dynamicSizes,
1795         dynamicStrides, b.getI64ArrayAttr(staticOffsets),
1796         b.getI64ArrayAttr(staticSizes), b.getI64ArrayAttr(staticStrides));
1797   result.addAttributes(attrs);
1798 }
1799 
1800 // Build a SubViewOp with mixed static and dynamic entries and inferred result
1801 // type.
1802 void SubViewOp::build(OpBuilder &b, OperationState &result, Value source,
1803                       ArrayRef<OpFoldResult> offsets,
1804                       ArrayRef<OpFoldResult> sizes,
1805                       ArrayRef<OpFoldResult> strides,
1806                       ArrayRef<NamedAttribute> attrs) {
1807   build(b, result, MemRefType(), source, offsets, sizes, strides, attrs);
1808 }
1809 
1810 // Build a SubViewOp with static entries and inferred result type.
1811 void SubViewOp::build(OpBuilder &b, OperationState &result, Value source,
1812                       ArrayRef<int64_t> offsets, ArrayRef<int64_t> sizes,
1813                       ArrayRef<int64_t> strides,
1814                       ArrayRef<NamedAttribute> attrs) {
1815   SmallVector<OpFoldResult> offsetValues = llvm::to_vector<4>(
1816       llvm::map_range(offsets, [&](int64_t v) -> OpFoldResult {
1817         return b.getI64IntegerAttr(v);
1818       }));
1819   SmallVector<OpFoldResult> sizeValues =
1820       llvm::to_vector<4>(llvm::map_range(sizes, [&](int64_t v) -> OpFoldResult {
1821         return b.getI64IntegerAttr(v);
1822       }));
1823   SmallVector<OpFoldResult> strideValues = llvm::to_vector<4>(
1824       llvm::map_range(strides, [&](int64_t v) -> OpFoldResult {
1825         return b.getI64IntegerAttr(v);
1826       }));
1827   build(b, result, source, offsetValues, sizeValues, strideValues, attrs);
1828 }
1829 
1830 // Build a SubViewOp with dynamic entries and custom result type. If the
1831 // type passed is nullptr, it is inferred.
1832 void SubViewOp::build(OpBuilder &b, OperationState &result,
1833                       MemRefType resultType, Value source,
1834                       ArrayRef<int64_t> offsets, ArrayRef<int64_t> sizes,
1835                       ArrayRef<int64_t> strides,
1836                       ArrayRef<NamedAttribute> attrs) {
1837   SmallVector<OpFoldResult> offsetValues = llvm::to_vector<4>(
1838       llvm::map_range(offsets, [&](int64_t v) -> OpFoldResult {
1839         return b.getI64IntegerAttr(v);
1840       }));
1841   SmallVector<OpFoldResult> sizeValues =
1842       llvm::to_vector<4>(llvm::map_range(sizes, [&](int64_t v) -> OpFoldResult {
1843         return b.getI64IntegerAttr(v);
1844       }));
1845   SmallVector<OpFoldResult> strideValues = llvm::to_vector<4>(
1846       llvm::map_range(strides, [&](int64_t v) -> OpFoldResult {
1847         return b.getI64IntegerAttr(v);
1848       }));
1849   build(b, result, resultType, source, offsetValues, sizeValues, strideValues,
1850         attrs);
1851 }
1852 
1853 // Build a SubViewOp with dynamic entries and custom result type. If the type
1854 // passed is nullptr, it is inferred.
1855 void SubViewOp::build(OpBuilder &b, OperationState &result,
1856                       MemRefType resultType, Value source, ValueRange offsets,
1857                       ValueRange sizes, ValueRange strides,
1858                       ArrayRef<NamedAttribute> attrs) {
1859   SmallVector<OpFoldResult> offsetValues = llvm::to_vector<4>(
1860       llvm::map_range(offsets, [](Value v) -> OpFoldResult { return v; }));
1861   SmallVector<OpFoldResult> sizeValues = llvm::to_vector<4>(
1862       llvm::map_range(sizes, [](Value v) -> OpFoldResult { return v; }));
1863   SmallVector<OpFoldResult> strideValues = llvm::to_vector<4>(
1864       llvm::map_range(strides, [](Value v) -> OpFoldResult { return v; }));
1865   build(b, result, resultType, source, offsetValues, sizeValues, strideValues);
1866 }
1867 
1868 // Build a SubViewOp with dynamic entries and inferred result type.
1869 void SubViewOp::build(OpBuilder &b, OperationState &result, Value source,
1870                       ValueRange offsets, ValueRange sizes, ValueRange strides,
1871                       ArrayRef<NamedAttribute> attrs) {
1872   build(b, result, MemRefType(), source, offsets, sizes, strides, attrs);
1873 }
1874 
1875 /// For ViewLikeOpInterface.
1876 Value SubViewOp::getViewSource() { return source(); }
1877 
1878 /// Return true if t1 and t2 have equal offsets (both dynamic or of same static
1879 /// value).
1880 static bool haveCompatibleOffsets(MemRefType t1, MemRefType t2) {
1881   AffineExpr t1Offset, t2Offset;
1882   SmallVector<AffineExpr> t1Strides, t2Strides;
1883   auto res1 = getStridesAndOffset(t1, t1Strides, t1Offset);
1884   auto res2 = getStridesAndOffset(t2, t2Strides, t2Offset);
1885   return succeeded(res1) && succeeded(res2) && t1Offset == t2Offset;
1886 }
1887 
1888 /// Checks if `original` Type type can be rank reduced to `reduced` type.
1889 /// This function is slight variant of `is subsequence` algorithm where
1890 /// not matching dimension must be 1.
1891 static SliceVerificationResult
1892 isRankReducedMemRefType(MemRefType originalType,
1893                         MemRefType candidateRankReducedType,
1894                         ArrayRef<OpFoldResult> sizes) {
1895   auto partialRes = isRankReducedType(originalType, candidateRankReducedType);
1896   if (partialRes != SliceVerificationResult::Success)
1897     return partialRes;
1898 
1899   auto optionalUnusedDimsMask = computeMemRefRankReductionMask(
1900       originalType, candidateRankReducedType, sizes);
1901 
1902   // Sizes cannot be matched in case empty vector is returned.
1903   if (!optionalUnusedDimsMask.hasValue())
1904     return SliceVerificationResult::LayoutMismatch;
1905 
1906   if (originalType.getMemorySpace() !=
1907       candidateRankReducedType.getMemorySpace())
1908     return SliceVerificationResult::MemSpaceMismatch;
1909 
1910   // No amount of stride dropping can reconcile incompatible offsets.
1911   if (!haveCompatibleOffsets(originalType, candidateRankReducedType))
1912     return SliceVerificationResult::LayoutMismatch;
1913 
1914   return SliceVerificationResult::Success;
1915 }
1916 
1917 template <typename OpTy>
1918 static LogicalResult produceSubViewErrorMsg(SliceVerificationResult result,
1919                                             OpTy op, Type expectedType) {
1920   auto memrefType = expectedType.cast<ShapedType>();
1921   switch (result) {
1922   case SliceVerificationResult::Success:
1923     return success();
1924   case SliceVerificationResult::RankTooLarge:
1925     return op.emitError("expected result rank to be smaller or equal to ")
1926            << "the source rank. ";
1927   case SliceVerificationResult::SizeMismatch:
1928     return op.emitError("expected result type to be ")
1929            << expectedType
1930            << " or a rank-reduced version. (mismatch of result sizes) ";
1931   case SliceVerificationResult::ElemTypeMismatch:
1932     return op.emitError("expected result element type to be ")
1933            << memrefType.getElementType();
1934   case SliceVerificationResult::MemSpaceMismatch:
1935     return op.emitError("expected result and source memory spaces to match.");
1936   case SliceVerificationResult::LayoutMismatch:
1937     return op.emitError("expected result type to be ")
1938            << expectedType
1939            << " or a rank-reduced version. (mismatch of result layout) ";
1940   }
1941   llvm_unreachable("unexpected subview verification result");
1942 }
1943 
1944 /// Verifier for SubViewOp.
1945 LogicalResult SubViewOp::verify() {
1946   MemRefType baseType = getSourceType();
1947   MemRefType subViewType = getType();
1948 
1949   // The base memref and the view memref should be in the same memory space.
1950   if (baseType.getMemorySpace() != subViewType.getMemorySpace())
1951     return emitError("different memory spaces specified for base memref "
1952                      "type ")
1953            << baseType << " and subview memref type " << subViewType;
1954 
1955   // Verify that the base memref type has a strided layout map.
1956   if (!isStrided(baseType))
1957     return emitError("base type ") << baseType << " is not strided";
1958 
1959   // Verify result type against inferred type.
1960   auto expectedType = SubViewOp::inferResultType(
1961       baseType, extractFromI64ArrayAttr(static_offsets()),
1962       extractFromI64ArrayAttr(static_sizes()),
1963       extractFromI64ArrayAttr(static_strides()));
1964 
1965   auto result = isRankReducedMemRefType(expectedType.cast<MemRefType>(),
1966                                         subViewType, getMixedSizes());
1967   return produceSubViewErrorMsg(result, *this, expectedType);
1968 }
1969 
1970 raw_ostream &mlir::operator<<(raw_ostream &os, const Range &range) {
1971   return os << "range " << range.offset << ":" << range.size << ":"
1972             << range.stride;
1973 }
1974 
1975 /// Return the list of Range (i.e. offset, size, stride). Each Range
1976 /// entry contains either the dynamic value or a ConstantIndexOp constructed
1977 /// with `b` at location `loc`.
1978 SmallVector<Range, 8> mlir::getOrCreateRanges(OffsetSizeAndStrideOpInterface op,
1979                                               OpBuilder &b, Location loc) {
1980   std::array<unsigned, 3> ranks = op.getArrayAttrMaxRanks();
1981   assert(ranks[0] == ranks[1] && "expected offset and sizes of equal ranks");
1982   assert(ranks[1] == ranks[2] && "expected sizes and strides of equal ranks");
1983   SmallVector<Range, 8> res;
1984   unsigned rank = ranks[0];
1985   res.reserve(rank);
1986   for (unsigned idx = 0; idx < rank; ++idx) {
1987     Value offset =
1988         op.isDynamicOffset(idx)
1989             ? op.getDynamicOffset(idx)
1990             : b.create<arith::ConstantIndexOp>(loc, op.getStaticOffset(idx));
1991     Value size =
1992         op.isDynamicSize(idx)
1993             ? op.getDynamicSize(idx)
1994             : b.create<arith::ConstantIndexOp>(loc, op.getStaticSize(idx));
1995     Value stride =
1996         op.isDynamicStride(idx)
1997             ? op.getDynamicStride(idx)
1998             : b.create<arith::ConstantIndexOp>(loc, op.getStaticStride(idx));
1999     res.emplace_back(Range{offset, size, stride});
2000   }
2001   return res;
2002 }
2003 
2004 /// Compute the canonical result type of a SubViewOp. Call `inferResultType` to
2005 /// deduce the result type for the given `sourceType`. Additionally, reduce the
2006 /// rank of the inferred result type if `currentResultType` is lower rank than
2007 /// `currentSourceType`. Use this signature if `sourceType` is updated together
2008 /// with the result type. In this case, it is important to compute the dropped
2009 /// dimensions using `currentSourceType` whose strides align with
2010 /// `currentResultType`.
2011 static MemRefType getCanonicalSubViewResultType(
2012     MemRefType currentResultType, MemRefType currentSourceType,
2013     MemRefType sourceType, ArrayRef<OpFoldResult> mixedOffsets,
2014     ArrayRef<OpFoldResult> mixedSizes, ArrayRef<OpFoldResult> mixedStrides) {
2015   auto nonRankReducedType = SubViewOp::inferResultType(sourceType, mixedOffsets,
2016                                                        mixedSizes, mixedStrides)
2017                                 .cast<MemRefType>();
2018   llvm::Optional<llvm::SmallDenseSet<unsigned>> unusedDims =
2019       computeMemRefRankReductionMask(currentSourceType, currentResultType,
2020                                      mixedSizes);
2021   // Return nullptr as failure mode.
2022   if (!unusedDims)
2023     return nullptr;
2024   SmallVector<int64_t> shape;
2025   for (const auto &sizes : llvm::enumerate(nonRankReducedType.getShape())) {
2026     if (unusedDims->count(sizes.index()))
2027       continue;
2028     shape.push_back(sizes.value());
2029   }
2030   AffineMap layoutMap = nonRankReducedType.getLayout().getAffineMap();
2031   if (!layoutMap.isIdentity())
2032     layoutMap = getProjectedMap(layoutMap, unusedDims.getValue());
2033   return MemRefType::get(shape, nonRankReducedType.getElementType(), layoutMap,
2034                          nonRankReducedType.getMemorySpace());
2035 }
2036 
2037 /// Compute the canonical result type of a SubViewOp. Call `inferResultType` to
2038 /// deduce the result type. Additionally, reduce the rank of the inferred result
2039 /// type if `currentResultType` is lower rank than `sourceType`.
2040 static MemRefType getCanonicalSubViewResultType(
2041     MemRefType currentResultType, MemRefType sourceType,
2042     ArrayRef<OpFoldResult> mixedOffsets, ArrayRef<OpFoldResult> mixedSizes,
2043     ArrayRef<OpFoldResult> mixedStrides) {
2044   return getCanonicalSubViewResultType(currentResultType, sourceType,
2045                                        sourceType, mixedOffsets, mixedSizes,
2046                                        mixedStrides);
2047 }
2048 
2049 /// Helper method to check if a `subview` operation is trivially a no-op. This
2050 /// is the case if the all offsets are zero, all strides are 1, and the source
2051 /// shape is same as the size of the subview. In such cases, the subview can be
2052 /// folded into its source.
2053 static bool isTrivialSubViewOp(SubViewOp subViewOp) {
2054   if (subViewOp.getSourceType().getRank() != subViewOp.getType().getRank())
2055     return false;
2056 
2057   auto mixedOffsets = subViewOp.getMixedOffsets();
2058   auto mixedSizes = subViewOp.getMixedSizes();
2059   auto mixedStrides = subViewOp.getMixedStrides();
2060 
2061   // Check offsets are zero.
2062   if (llvm::any_of(mixedOffsets, [](OpFoldResult ofr) {
2063         Optional<int64_t> intValue = getConstantIntValue(ofr);
2064         return !intValue || intValue.getValue() != 0;
2065       }))
2066     return false;
2067 
2068   // Check strides are one.
2069   if (llvm::any_of(mixedStrides, [](OpFoldResult ofr) {
2070         Optional<int64_t> intValue = getConstantIntValue(ofr);
2071         return !intValue || intValue.getValue() != 1;
2072       }))
2073     return false;
2074 
2075   // Check all size values are static and matches the (static) source shape.
2076   ArrayRef<int64_t> sourceShape = subViewOp.getSourceType().getShape();
2077   for (const auto &size : llvm::enumerate(mixedSizes)) {
2078     Optional<int64_t> intValue = getConstantIntValue(size.value());
2079     if (!intValue || intValue.getValue() != sourceShape[size.index()])
2080       return false;
2081   }
2082   // All conditions met. The `SubViewOp` is foldable as a no-op.
2083   return true;
2084 }
2085 
2086 namespace {
2087 /// Pattern to rewrite a subview op with MemRefCast arguments.
2088 /// This essentially pushes memref.cast past its consuming subview when
2089 /// `canFoldIntoConsumerOp` is true.
2090 ///
2091 /// Example:
2092 /// ```
2093 ///   %0 = memref.cast %V : memref<16x16xf32> to memref<?x?xf32>
2094 ///   %1 = memref.subview %0[0, 0][3, 4][1, 1] :
2095 ///     memref<?x?xf32> to memref<3x4xf32, offset:?, strides:[?, 1]>
2096 /// ```
2097 /// is rewritten into:
2098 /// ```
2099 ///   %0 = memref.subview %V: memref<16x16xf32> to memref<3x4xf32, #[[map0]]>
2100 ///   %1 = memref.cast %0: memref<3x4xf32, offset:0, strides:[16, 1]> to
2101 ///     memref<3x4xf32, offset:?, strides:[?, 1]>
2102 /// ```
2103 class SubViewOpMemRefCastFolder final : public OpRewritePattern<SubViewOp> {
2104 public:
2105   using OpRewritePattern<SubViewOp>::OpRewritePattern;
2106 
2107   LogicalResult matchAndRewrite(SubViewOp subViewOp,
2108                                 PatternRewriter &rewriter) const override {
2109     // Any constant operand, just return to let SubViewOpConstantFolder kick in.
2110     if (llvm::any_of(subViewOp.getOperands(), [](Value operand) {
2111           return matchPattern(operand, matchConstantIndex());
2112         }))
2113       return failure();
2114 
2115     auto castOp = subViewOp.source().getDefiningOp<CastOp>();
2116     if (!castOp)
2117       return failure();
2118 
2119     if (!CastOp::canFoldIntoConsumerOp(castOp))
2120       return failure();
2121 
2122     // Compute the SubViewOp result type after folding the MemRefCastOp. Use the
2123     // MemRefCastOp source operand type to infer the result type and the current
2124     // SubViewOp source operand type to compute the dropped dimensions if the
2125     // operation is rank-reducing.
2126     auto resultType = getCanonicalSubViewResultType(
2127         subViewOp.getType(), subViewOp.getSourceType(),
2128         castOp.source().getType().cast<MemRefType>(),
2129         subViewOp.getMixedOffsets(), subViewOp.getMixedSizes(),
2130         subViewOp.getMixedStrides());
2131     if (!resultType)
2132       return failure();
2133 
2134     Value newSubView = rewriter.create<SubViewOp>(
2135         subViewOp.getLoc(), resultType, castOp.source(), subViewOp.offsets(),
2136         subViewOp.sizes(), subViewOp.strides(), subViewOp.static_offsets(),
2137         subViewOp.static_sizes(), subViewOp.static_strides());
2138     rewriter.replaceOpWithNewOp<CastOp>(subViewOp, subViewOp.getType(),
2139                                         newSubView);
2140     return success();
2141   }
2142 };
2143 
2144 /// Canonicalize subview ops that are no-ops. When the source shape is not same
2145 /// as a result shape due to use of `affine_map`.
2146 class TrivialSubViewOpFolder final : public OpRewritePattern<SubViewOp> {
2147 public:
2148   using OpRewritePattern<SubViewOp>::OpRewritePattern;
2149 
2150   LogicalResult matchAndRewrite(SubViewOp subViewOp,
2151                                 PatternRewriter &rewriter) const override {
2152     if (!isTrivialSubViewOp(subViewOp))
2153       return failure();
2154     if (subViewOp.getSourceType() == subViewOp.getType()) {
2155       rewriter.replaceOp(subViewOp, subViewOp.source());
2156       return success();
2157     }
2158     rewriter.replaceOpWithNewOp<CastOp>(subViewOp, subViewOp.source(),
2159                                         subViewOp.getType());
2160     return success();
2161   }
2162 };
2163 } // namespace
2164 
2165 /// Return the canonical type of the result of a subview.
2166 struct SubViewReturnTypeCanonicalizer {
2167   MemRefType operator()(SubViewOp op, ArrayRef<OpFoldResult> mixedOffsets,
2168                         ArrayRef<OpFoldResult> mixedSizes,
2169                         ArrayRef<OpFoldResult> mixedStrides) {
2170     return getCanonicalSubViewResultType(op.getType(), op.getSourceType(),
2171                                          mixedOffsets, mixedSizes,
2172                                          mixedStrides);
2173   }
2174 };
2175 
2176 /// A canonicalizer wrapper to replace SubViewOps.
2177 struct SubViewCanonicalizer {
2178   void operator()(PatternRewriter &rewriter, SubViewOp op, SubViewOp newOp) {
2179     rewriter.replaceOpWithNewOp<CastOp>(op, newOp, op.getType());
2180   }
2181 };
2182 
2183 void SubViewOp::getCanonicalizationPatterns(RewritePatternSet &results,
2184                                             MLIRContext *context) {
2185   results
2186       .add<OpWithOffsetSizesAndStridesConstantArgumentFolder<
2187                SubViewOp, SubViewReturnTypeCanonicalizer, SubViewCanonicalizer>,
2188            SubViewOpMemRefCastFolder, TrivialSubViewOpFolder>(context);
2189 }
2190 
2191 OpFoldResult SubViewOp::fold(ArrayRef<Attribute> operands) {
2192   auto resultShapedType = getResult().getType().cast<ShapedType>();
2193   auto sourceShapedType = source().getType().cast<ShapedType>();
2194 
2195   if (resultShapedType.hasStaticShape() &&
2196       resultShapedType == sourceShapedType) {
2197     return getViewSource();
2198   }
2199 
2200   return {};
2201 }
2202 
2203 //===----------------------------------------------------------------------===//
2204 // TransposeOp
2205 //===----------------------------------------------------------------------===//
2206 
2207 /// Build a strided memref type by applying `permutationMap` tp `memRefType`.
2208 static MemRefType inferTransposeResultType(MemRefType memRefType,
2209                                            AffineMap permutationMap) {
2210   auto rank = memRefType.getRank();
2211   auto originalSizes = memRefType.getShape();
2212   // Compute permuted sizes.
2213   SmallVector<int64_t, 4> sizes(rank, 0);
2214   for (const auto &en : llvm::enumerate(permutationMap.getResults()))
2215     sizes[en.index()] =
2216         originalSizes[en.value().cast<AffineDimExpr>().getPosition()];
2217 
2218   // Compute permuted strides.
2219   int64_t offset;
2220   SmallVector<int64_t, 4> strides;
2221   auto res = getStridesAndOffset(memRefType, strides, offset);
2222   assert(succeeded(res) && strides.size() == static_cast<unsigned>(rank));
2223   (void)res;
2224   auto map =
2225       makeStridedLinearLayoutMap(strides, offset, memRefType.getContext());
2226   map = permutationMap ? map.compose(permutationMap) : map;
2227   return MemRefType::Builder(memRefType)
2228       .setShape(sizes)
2229       .setLayout(AffineMapAttr::get(map));
2230 }
2231 
2232 void TransposeOp::build(OpBuilder &b, OperationState &result, Value in,
2233                         AffineMapAttr permutation,
2234                         ArrayRef<NamedAttribute> attrs) {
2235   auto permutationMap = permutation.getValue();
2236   assert(permutationMap);
2237 
2238   auto memRefType = in.getType().cast<MemRefType>();
2239   // Compute result type.
2240   MemRefType resultType = inferTransposeResultType(memRefType, permutationMap);
2241 
2242   build(b, result, resultType, in, attrs);
2243   result.addAttribute(TransposeOp::getPermutationAttrName(), permutation);
2244 }
2245 
2246 // transpose $in $permutation attr-dict : type($in) `to` type(results)
2247 static void print(OpAsmPrinter &p, TransposeOp op) {
2248   p << " " << op.in() << " " << op.permutation();
2249   p.printOptionalAttrDict(op->getAttrs(),
2250                           {TransposeOp::getPermutationAttrName()});
2251   p << " : " << op.in().getType() << " to " << op.getType();
2252 }
2253 
2254 static ParseResult parseTransposeOp(OpAsmParser &parser,
2255                                     OperationState &result) {
2256   OpAsmParser::OperandType in;
2257   AffineMap permutation;
2258   MemRefType srcType, dstType;
2259   if (parser.parseOperand(in) || parser.parseAffineMap(permutation) ||
2260       parser.parseOptionalAttrDict(result.attributes) ||
2261       parser.parseColonType(srcType) ||
2262       parser.resolveOperand(in, srcType, result.operands) ||
2263       parser.parseKeywordType("to", dstType) ||
2264       parser.addTypeToList(dstType, result.types))
2265     return failure();
2266 
2267   result.addAttribute(TransposeOp::getPermutationAttrName(),
2268                       AffineMapAttr::get(permutation));
2269   return success();
2270 }
2271 
2272 LogicalResult TransposeOp::verify() {
2273   if (!permutation().isPermutation())
2274     return emitOpError("expected a permutation map");
2275   if (permutation().getNumDims() != getShapedType().getRank())
2276     return emitOpError("expected a permutation map of same rank as the input");
2277 
2278   auto srcType = in().getType().cast<MemRefType>();
2279   auto dstType = getType().cast<MemRefType>();
2280   auto transposedType = inferTransposeResultType(srcType, permutation());
2281   if (dstType != transposedType)
2282     return emitOpError("output type ")
2283            << dstType << " does not match transposed input type " << srcType
2284            << ", " << transposedType;
2285   return success();
2286 }
2287 
2288 OpFoldResult TransposeOp::fold(ArrayRef<Attribute>) {
2289   if (succeeded(foldMemRefCast(*this)))
2290     return getResult();
2291   return {};
2292 }
2293 
2294 //===----------------------------------------------------------------------===//
2295 // ViewOp
2296 //===----------------------------------------------------------------------===//
2297 
2298 static ParseResult parseViewOp(OpAsmParser &parser, OperationState &result) {
2299   OpAsmParser::OperandType srcInfo;
2300   SmallVector<OpAsmParser::OperandType, 1> offsetInfo;
2301   SmallVector<OpAsmParser::OperandType, 4> sizesInfo;
2302   auto indexType = parser.getBuilder().getIndexType();
2303   Type srcType, dstType;
2304   SMLoc offsetLoc;
2305   if (parser.parseOperand(srcInfo) || parser.getCurrentLocation(&offsetLoc) ||
2306       parser.parseOperandList(offsetInfo, OpAsmParser::Delimiter::Square))
2307     return failure();
2308 
2309   if (offsetInfo.size() != 1)
2310     return parser.emitError(offsetLoc) << "expects 1 offset operand";
2311 
2312   return failure(
2313       parser.parseOperandList(sizesInfo, OpAsmParser::Delimiter::Square) ||
2314       parser.parseOptionalAttrDict(result.attributes) ||
2315       parser.parseColonType(srcType) ||
2316       parser.resolveOperand(srcInfo, srcType, result.operands) ||
2317       parser.resolveOperands(offsetInfo, indexType, result.operands) ||
2318       parser.resolveOperands(sizesInfo, indexType, result.operands) ||
2319       parser.parseKeywordType("to", dstType) ||
2320       parser.addTypeToList(dstType, result.types));
2321 }
2322 
2323 static void print(OpAsmPrinter &p, ViewOp op) {
2324   p << ' ' << op.getOperand(0) << '[';
2325   p.printOperand(op.byte_shift());
2326   p << "][" << op.sizes() << ']';
2327   p.printOptionalAttrDict(op->getAttrs());
2328   p << " : " << op.getOperand(0).getType() << " to " << op.getType();
2329 }
2330 
2331 LogicalResult ViewOp::verify() {
2332   auto baseType = getOperand(0).getType().cast<MemRefType>();
2333   auto viewType = getType();
2334 
2335   // The base memref should have identity layout map (or none).
2336   if (!baseType.getLayout().isIdentity())
2337     return emitError("unsupported map for base memref type ") << baseType;
2338 
2339   // The result memref should have identity layout map (or none).
2340   if (!viewType.getLayout().isIdentity())
2341     return emitError("unsupported map for result memref type ") << viewType;
2342 
2343   // The base memref and the view memref should be in the same memory space.
2344   if (baseType.getMemorySpace() != viewType.getMemorySpace())
2345     return emitError("different memory spaces specified for base memref "
2346                      "type ")
2347            << baseType << " and view memref type " << viewType;
2348 
2349   // Verify that we have the correct number of sizes for the result type.
2350   unsigned numDynamicDims = viewType.getNumDynamicDims();
2351   if (sizes().size() != numDynamicDims)
2352     return emitError("incorrect number of size operands for type ") << viewType;
2353 
2354   return success();
2355 }
2356 
2357 Value ViewOp::getViewSource() { return source(); }
2358 
2359 namespace {
2360 
2361 struct ViewOpShapeFolder : public OpRewritePattern<ViewOp> {
2362   using OpRewritePattern<ViewOp>::OpRewritePattern;
2363 
2364   LogicalResult matchAndRewrite(ViewOp viewOp,
2365                                 PatternRewriter &rewriter) const override {
2366     // Return if none of the operands are constants.
2367     if (llvm::none_of(viewOp.getOperands(), [](Value operand) {
2368           return matchPattern(operand, matchConstantIndex());
2369         }))
2370       return failure();
2371 
2372     // Get result memref type.
2373     auto memrefType = viewOp.getType();
2374 
2375     // Get offset from old memref view type 'memRefType'.
2376     int64_t oldOffset;
2377     SmallVector<int64_t, 4> oldStrides;
2378     if (failed(getStridesAndOffset(memrefType, oldStrides, oldOffset)))
2379       return failure();
2380     assert(oldOffset == 0 && "Expected 0 offset");
2381 
2382     SmallVector<Value, 4> newOperands;
2383 
2384     // Offset cannot be folded into result type.
2385 
2386     // Fold any dynamic dim operands which are produced by a constant.
2387     SmallVector<int64_t, 4> newShapeConstants;
2388     newShapeConstants.reserve(memrefType.getRank());
2389 
2390     unsigned dynamicDimPos = 0;
2391     unsigned rank = memrefType.getRank();
2392     for (unsigned dim = 0, e = rank; dim < e; ++dim) {
2393       int64_t dimSize = memrefType.getDimSize(dim);
2394       // If this is already static dimension, keep it.
2395       if (!ShapedType::isDynamic(dimSize)) {
2396         newShapeConstants.push_back(dimSize);
2397         continue;
2398       }
2399       auto *defOp = viewOp.sizes()[dynamicDimPos].getDefiningOp();
2400       if (auto constantIndexOp =
2401               dyn_cast_or_null<arith::ConstantIndexOp>(defOp)) {
2402         // Dynamic shape dimension will be folded.
2403         newShapeConstants.push_back(constantIndexOp.value());
2404       } else {
2405         // Dynamic shape dimension not folded; copy operand from old memref.
2406         newShapeConstants.push_back(dimSize);
2407         newOperands.push_back(viewOp.sizes()[dynamicDimPos]);
2408       }
2409       dynamicDimPos++;
2410     }
2411 
2412     // Create new memref type with constant folded dims.
2413     MemRefType newMemRefType =
2414         MemRefType::Builder(memrefType).setShape(newShapeConstants);
2415     // Nothing new, don't fold.
2416     if (newMemRefType == memrefType)
2417       return failure();
2418 
2419     // Create new ViewOp.
2420     auto newViewOp = rewriter.create<ViewOp>(viewOp.getLoc(), newMemRefType,
2421                                              viewOp.getOperand(0),
2422                                              viewOp.byte_shift(), newOperands);
2423     // Insert a cast so we have the same type as the old memref type.
2424     rewriter.replaceOpWithNewOp<CastOp>(viewOp, newViewOp, viewOp.getType());
2425     return success();
2426   }
2427 };
2428 
2429 struct ViewOpMemrefCastFolder : public OpRewritePattern<ViewOp> {
2430   using OpRewritePattern<ViewOp>::OpRewritePattern;
2431 
2432   LogicalResult matchAndRewrite(ViewOp viewOp,
2433                                 PatternRewriter &rewriter) const override {
2434     Value memrefOperand = viewOp.getOperand(0);
2435     CastOp memrefCastOp = memrefOperand.getDefiningOp<CastOp>();
2436     if (!memrefCastOp)
2437       return failure();
2438     Value allocOperand = memrefCastOp.getOperand();
2439     AllocOp allocOp = allocOperand.getDefiningOp<AllocOp>();
2440     if (!allocOp)
2441       return failure();
2442     rewriter.replaceOpWithNewOp<ViewOp>(viewOp, viewOp.getType(), allocOperand,
2443                                         viewOp.byte_shift(), viewOp.sizes());
2444     return success();
2445   }
2446 };
2447 
2448 } // namespace
2449 
2450 void ViewOp::getCanonicalizationPatterns(RewritePatternSet &results,
2451                                          MLIRContext *context) {
2452   results.add<ViewOpShapeFolder, ViewOpMemrefCastFolder>(context);
2453 }
2454 
2455 //===----------------------------------------------------------------------===//
2456 // AtomicRMWOp
2457 //===----------------------------------------------------------------------===//
2458 
2459 LogicalResult AtomicRMWOp::verify() {
2460   if (getMemRefType().getRank() != getNumOperands() - 2)
2461     return emitOpError(
2462         "expects the number of subscripts to be equal to memref rank");
2463   switch (kind()) {
2464   case arith::AtomicRMWKind::addf:
2465   case arith::AtomicRMWKind::maxf:
2466   case arith::AtomicRMWKind::minf:
2467   case arith::AtomicRMWKind::mulf:
2468     if (!value().getType().isa<FloatType>())
2469       return emitOpError() << "with kind '"
2470                            << arith::stringifyAtomicRMWKind(kind())
2471                            << "' expects a floating-point type";
2472     break;
2473   case arith::AtomicRMWKind::addi:
2474   case arith::AtomicRMWKind::maxs:
2475   case arith::AtomicRMWKind::maxu:
2476   case arith::AtomicRMWKind::mins:
2477   case arith::AtomicRMWKind::minu:
2478   case arith::AtomicRMWKind::muli:
2479   case arith::AtomicRMWKind::ori:
2480   case arith::AtomicRMWKind::andi:
2481     if (!value().getType().isa<IntegerType>())
2482       return emitOpError() << "with kind '"
2483                            << arith::stringifyAtomicRMWKind(kind())
2484                            << "' expects an integer type";
2485     break;
2486   default:
2487     break;
2488   }
2489   return success();
2490 }
2491 
2492 OpFoldResult AtomicRMWOp::fold(ArrayRef<Attribute> operands) {
2493   /// atomicrmw(memrefcast) -> atomicrmw
2494   if (succeeded(foldMemRefCast(*this, value())))
2495     return getResult();
2496   return OpFoldResult();
2497 }
2498 
2499 //===----------------------------------------------------------------------===//
2500 // TableGen'd op method definitions
2501 //===----------------------------------------------------------------------===//
2502 
2503 #define GET_OP_CLASSES
2504 #include "mlir/Dialect/MemRef/IR/MemRefOps.cpp.inc"
2505