1 //===- Operation.cpp - Operation support code -----------------------------===//
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/IR/Operation.h"
10 #include "mlir/IR/BlockAndValueMapping.h"
11 #include "mlir/IR/BuiltinTypes.h"
12 #include "mlir/IR/Dialect.h"
13 #include "mlir/IR/OpImplementation.h"
14 #include "mlir/IR/PatternMatch.h"
15 #include "mlir/IR/TypeUtilities.h"
16 #include "mlir/Interfaces/FoldInterfaces.h"
17 #include <numeric>
18 
19 using namespace mlir;
20 
21 OpAsmParser::~OpAsmParser() {}
22 
23 //===----------------------------------------------------------------------===//
24 // OperationName
25 //===----------------------------------------------------------------------===//
26 
27 /// Form the OperationName for an op with the specified string.  This either is
28 /// a reference to an AbstractOperation if one is known, or a uniqued Identifier
29 /// if not.
30 OperationName::OperationName(StringRef name, MLIRContext *context) {
31   if (auto *op = AbstractOperation::lookup(name, context))
32     representation = op;
33   else
34     representation = Identifier::get(name, context);
35 }
36 
37 /// Return the name of the dialect this operation is registered to.
38 StringRef OperationName::getDialectNamespace() const {
39   if (Dialect *dialect = getDialect())
40     return dialect->getNamespace();
41   return representation.get<Identifier>().strref().split('.').first;
42 }
43 
44 /// Return the operation name with dialect name stripped, if it has one.
45 StringRef OperationName::stripDialect() const {
46   auto splitName = getStringRef().split(".");
47   return splitName.second.empty() ? splitName.first : splitName.second;
48 }
49 
50 /// Return the name of this operation. This always succeeds.
51 StringRef OperationName::getStringRef() const {
52   return getIdentifier().strref();
53 }
54 
55 /// Return the name of this operation as an identifier. This always succeeds.
56 Identifier OperationName::getIdentifier() const {
57   if (auto *op = representation.dyn_cast<const AbstractOperation *>())
58     return op->name;
59   return representation.get<Identifier>();
60 }
61 
62 OperationName OperationName::getFromOpaquePointer(const void *pointer) {
63   return OperationName(
64       RepresentationUnion::getFromOpaqueValue(const_cast<void *>(pointer)));
65 }
66 
67 //===----------------------------------------------------------------------===//
68 // Operation
69 //===----------------------------------------------------------------------===//
70 
71 /// Create a new Operation with the specific fields.
72 Operation *Operation::create(Location location, OperationName name,
73                              TypeRange resultTypes, ValueRange operands,
74                              ArrayRef<NamedAttribute> attributes,
75                              BlockRange successors, unsigned numRegions) {
76   return create(location, name, resultTypes, operands,
77                 DictionaryAttr::get(location.getContext(), attributes),
78                 successors, numRegions);
79 }
80 
81 /// Create a new Operation from operation state.
82 Operation *Operation::create(const OperationState &state) {
83   return create(state.location, state.name, state.types, state.operands,
84                 state.attributes.getDictionary(state.getContext()),
85                 state.successors, state.regions);
86 }
87 
88 /// Create a new Operation with the specific fields.
89 Operation *Operation::create(Location location, OperationName name,
90                              TypeRange resultTypes, ValueRange operands,
91                              DictionaryAttr attributes, BlockRange successors,
92                              RegionRange regions) {
93   unsigned numRegions = regions.size();
94   Operation *op = create(location, name, resultTypes, operands, attributes,
95                          successors, numRegions);
96   for (unsigned i = 0; i < numRegions; ++i)
97     if (regions[i])
98       op->getRegion(i).takeBody(*regions[i]);
99   return op;
100 }
101 
102 /// Overload of create that takes an existing DictionaryAttr to avoid
103 /// unnecessarily uniquing a list of attributes.
104 Operation *Operation::create(Location location, OperationName name,
105                              TypeRange resultTypes, ValueRange operands,
106                              DictionaryAttr attributes, BlockRange successors,
107                              unsigned numRegions) {
108   assert(llvm::all_of(resultTypes, [](Type t) { return t; }) &&
109          "unexpected null result type");
110 
111   // We only need to allocate additional memory for a subset of results.
112   unsigned numTrailingResults = OpResult::getNumTrailing(resultTypes.size());
113   unsigned numInlineResults = OpResult::getNumInline(resultTypes.size());
114   unsigned numSuccessors = successors.size();
115   unsigned numOperands = operands.size();
116   unsigned numResults = resultTypes.size();
117 
118   // If the operation is known to have no operands, don't allocate an operand
119   // storage.
120   bool needsOperandStorage = true;
121   if (operands.empty()) {
122     if (const AbstractOperation *abstractOp = name.getAbstractOperation())
123       needsOperandStorage = !abstractOp->hasTrait<OpTrait::ZeroOperands>();
124   }
125 
126   // Compute the byte size for the operation and the operand storage. This takes
127   // into account the size of the operation, its trailing objects, and its
128   // prefixed objects.
129   size_t byteSize =
130       totalSizeToAlloc<BlockOperand, Region, detail::OperandStorage>(
131           numSuccessors, numRegions, needsOperandStorage ? 1 : 0) +
132       detail::OperandStorage::additionalAllocSize(numOperands);
133   size_t prefixByteSize = llvm::alignTo(
134       Operation::prefixAllocSize(numTrailingResults, numInlineResults),
135       alignof(Operation));
136   char *mallocMem = reinterpret_cast<char *>(malloc(byteSize + prefixByteSize));
137   void *rawMem = mallocMem + prefixByteSize;
138 
139   // Create the new Operation.
140   Operation *op =
141       ::new (rawMem) Operation(location, name, numResults, numSuccessors,
142                                numRegions, attributes, needsOperandStorage);
143 
144   assert((numSuccessors == 0 || op->mightHaveTrait<OpTrait::IsTerminator>()) &&
145          "unexpected successors in a non-terminator operation");
146 
147   // Initialize the results.
148   auto resultTypeIt = resultTypes.begin();
149   for (unsigned i = 0; i < numInlineResults; ++i, ++resultTypeIt)
150     new (op->getInlineOpResult(i)) detail::InlineOpResult(*resultTypeIt, i);
151   for (unsigned i = 0; i < numTrailingResults; ++i, ++resultTypeIt) {
152     new (op->getOutOfLineOpResult(i))
153         detail::OutOfLineOpResult(*resultTypeIt, i);
154   }
155 
156   // Initialize the regions.
157   for (unsigned i = 0; i != numRegions; ++i)
158     new (&op->getRegion(i)) Region(op);
159 
160   // Initialize the operands.
161   if (needsOperandStorage)
162     new (&op->getOperandStorage()) detail::OperandStorage(op, operands);
163 
164   // Initialize the successors.
165   auto blockOperands = op->getBlockOperands();
166   for (unsigned i = 0; i != numSuccessors; ++i)
167     new (&blockOperands[i]) BlockOperand(op, successors[i]);
168 
169   return op;
170 }
171 
172 Operation::Operation(Location location, OperationName name, unsigned numResults,
173                      unsigned numSuccessors, unsigned numRegions,
174                      DictionaryAttr attributes, bool hasOperandStorage)
175     : location(location), numResults(numResults), numSuccs(numSuccessors),
176       numRegions(numRegions), hasOperandStorage(hasOperandStorage), name(name),
177       attrs(attributes) {
178   assert(attributes && "unexpected null attribute dictionary");
179 #ifndef NDEBUG
180   if (!getDialect() && !getContext()->allowsUnregisteredDialects())
181     llvm::report_fatal_error(
182         name.getStringRef() +
183         " created with unregistered dialect. If this is intended, please call "
184         "allowUnregisteredDialects() on the MLIRContext, or use "
185         "-allow-unregistered-dialect with the MLIR opt tool used");
186 #endif
187 }
188 
189 // Operations are deleted through the destroy() member because they are
190 // allocated via malloc.
191 Operation::~Operation() {
192   assert(block == nullptr && "operation destroyed but still in a block");
193 #ifndef NDEBUG
194   if (!use_empty()) {
195     {
196       InFlightDiagnostic diag =
197           emitOpError("operation destroyed but still has uses");
198       for (Operation *user : getUsers())
199         diag.attachNote(user->getLoc()) << "- use: " << *user << "\n";
200     }
201     llvm::report_fatal_error("operation destroyed but still has uses");
202   }
203 #endif
204   // Explicitly run the destructors for the operands.
205   if (hasOperandStorage)
206     getOperandStorage().~OperandStorage();
207 
208   // Explicitly run the destructors for the successors.
209   for (auto &successor : getBlockOperands())
210     successor.~BlockOperand();
211 
212   // Explicitly destroy the regions.
213   for (auto &region : getRegions())
214     region.~Region();
215 }
216 
217 /// Destroy this operation or one of its subclasses.
218 void Operation::destroy() {
219   // Operations may have additional prefixed allocation, which needs to be
220   // accounted for here when computing the address to free.
221   char *rawMem = reinterpret_cast<char *>(this) -
222                  llvm::alignTo(prefixAllocSize(), alignof(Operation));
223   this->~Operation();
224   free(rawMem);
225 }
226 
227 /// Return true if this operation is a proper ancestor of the `other`
228 /// operation.
229 bool Operation::isProperAncestor(Operation *other) {
230   while ((other = other->getParentOp()))
231     if (this == other)
232       return true;
233   return false;
234 }
235 
236 /// Replace any uses of 'from' with 'to' within this operation.
237 void Operation::replaceUsesOfWith(Value from, Value to) {
238   if (from == to)
239     return;
240   for (auto &operand : getOpOperands())
241     if (operand.get() == from)
242       operand.set(to);
243 }
244 
245 /// Replace the current operands of this operation with the ones provided in
246 /// 'operands'.
247 void Operation::setOperands(ValueRange operands) {
248   if (LLVM_LIKELY(hasOperandStorage))
249     return getOperandStorage().setOperands(this, operands);
250   assert(operands.empty() && "setting operands without an operand storage");
251 }
252 
253 /// Replace the operands beginning at 'start' and ending at 'start' + 'length'
254 /// with the ones provided in 'operands'. 'operands' may be smaller or larger
255 /// than the range pointed to by 'start'+'length'.
256 void Operation::setOperands(unsigned start, unsigned length,
257                             ValueRange operands) {
258   assert((start + length) <= getNumOperands() &&
259          "invalid operand range specified");
260   if (LLVM_LIKELY(hasOperandStorage))
261     return getOperandStorage().setOperands(this, start, length, operands);
262   assert(operands.empty() && "setting operands without an operand storage");
263 }
264 
265 /// Insert the given operands into the operand list at the given 'index'.
266 void Operation::insertOperands(unsigned index, ValueRange operands) {
267   if (LLVM_LIKELY(hasOperandStorage))
268     return setOperands(index, /*length=*/0, operands);
269   assert(operands.empty() && "inserting operands without an operand storage");
270 }
271 
272 //===----------------------------------------------------------------------===//
273 // Diagnostics
274 //===----------------------------------------------------------------------===//
275 
276 /// Emit an error about fatal conditions with this operation, reporting up to
277 /// any diagnostic handlers that may be listening.
278 InFlightDiagnostic Operation::emitError(const Twine &message) {
279   InFlightDiagnostic diag = mlir::emitError(getLoc(), message);
280   if (getContext()->shouldPrintOpOnDiagnostic()) {
281     // Print out the operation explicitly here so that we can print the generic
282     // form.
283     // TODO: It would be nice if we could instead provide the
284     // specific printing flags when adding the operation as an argument to the
285     // diagnostic.
286     std::string printedOp;
287     {
288       llvm::raw_string_ostream os(printedOp);
289       print(os, OpPrintingFlags().printGenericOpForm().useLocalScope());
290     }
291     diag.attachNote(getLoc()) << "see current operation: " << printedOp;
292   }
293   return diag;
294 }
295 
296 /// Emit a warning about this operation, reporting up to any diagnostic
297 /// handlers that may be listening.
298 InFlightDiagnostic Operation::emitWarning(const Twine &message) {
299   InFlightDiagnostic diag = mlir::emitWarning(getLoc(), message);
300   if (getContext()->shouldPrintOpOnDiagnostic())
301     diag.attachNote(getLoc()) << "see current operation: " << *this;
302   return diag;
303 }
304 
305 /// Emit a remark about this operation, reporting up to any diagnostic
306 /// handlers that may be listening.
307 InFlightDiagnostic Operation::emitRemark(const Twine &message) {
308   InFlightDiagnostic diag = mlir::emitRemark(getLoc(), message);
309   if (getContext()->shouldPrintOpOnDiagnostic())
310     diag.attachNote(getLoc()) << "see current operation: " << *this;
311   return diag;
312 }
313 
314 //===----------------------------------------------------------------------===//
315 // Operation Ordering
316 //===----------------------------------------------------------------------===//
317 
318 constexpr unsigned Operation::kInvalidOrderIdx;
319 constexpr unsigned Operation::kOrderStride;
320 
321 /// Given an operation 'other' that is within the same parent block, return
322 /// whether the current operation is before 'other' in the operation list
323 /// of the parent block.
324 /// Note: This function has an average complexity of O(1), but worst case may
325 /// take O(N) where N is the number of operations within the parent block.
326 bool Operation::isBeforeInBlock(Operation *other) {
327   assert(block && "Operations without parent blocks have no order.");
328   assert(other && other->block == block &&
329          "Expected other operation to have the same parent block.");
330   // If the order of the block is already invalid, directly recompute the
331   // parent.
332   if (!block->isOpOrderValid()) {
333     block->recomputeOpOrder();
334   } else {
335     // Update the order either operation if necessary.
336     updateOrderIfNecessary();
337     other->updateOrderIfNecessary();
338   }
339 
340   return orderIndex < other->orderIndex;
341 }
342 
343 /// Update the order index of this operation of this operation if necessary,
344 /// potentially recomputing the order of the parent block.
345 void Operation::updateOrderIfNecessary() {
346   assert(block && "expected valid parent");
347 
348   // If the order is valid for this operation there is nothing to do.
349   if (hasValidOrder())
350     return;
351   Operation *blockFront = &block->front();
352   Operation *blockBack = &block->back();
353 
354   // This method is expected to only be invoked on blocks with more than one
355   // operation.
356   assert(blockFront != blockBack && "expected more than one operation");
357 
358   // If the operation is at the end of the block.
359   if (this == blockBack) {
360     Operation *prevNode = getPrevNode();
361     if (!prevNode->hasValidOrder())
362       return block->recomputeOpOrder();
363 
364     // Add the stride to the previous operation.
365     orderIndex = prevNode->orderIndex + kOrderStride;
366     return;
367   }
368 
369   // If this is the first operation try to use the next operation to compute the
370   // ordering.
371   if (this == blockFront) {
372     Operation *nextNode = getNextNode();
373     if (!nextNode->hasValidOrder())
374       return block->recomputeOpOrder();
375     // There is no order to give this operation.
376     if (nextNode->orderIndex == 0)
377       return block->recomputeOpOrder();
378 
379     // If we can't use the stride, just take the middle value left. This is safe
380     // because we know there is at least one valid index to assign to.
381     if (nextNode->orderIndex <= kOrderStride)
382       orderIndex = (nextNode->orderIndex / 2);
383     else
384       orderIndex = kOrderStride;
385     return;
386   }
387 
388   // Otherwise, this operation is between two others. Place this operation in
389   // the middle of the previous and next if possible.
390   Operation *prevNode = getPrevNode(), *nextNode = getNextNode();
391   if (!prevNode->hasValidOrder() || !nextNode->hasValidOrder())
392     return block->recomputeOpOrder();
393   unsigned prevOrder = prevNode->orderIndex, nextOrder = nextNode->orderIndex;
394 
395   // Check to see if there is a valid order between the two.
396   if (prevOrder + 1 == nextOrder)
397     return block->recomputeOpOrder();
398   orderIndex = prevOrder + ((nextOrder - prevOrder) / 2);
399 }
400 
401 //===----------------------------------------------------------------------===//
402 // ilist_traits for Operation
403 //===----------------------------------------------------------------------===//
404 
405 auto llvm::ilist_detail::SpecificNodeAccess<
406     typename llvm::ilist_detail::compute_node_options<
407         ::mlir::Operation>::type>::getNodePtr(pointer N) -> node_type * {
408   return NodeAccess::getNodePtr<OptionsT>(N);
409 }
410 
411 auto llvm::ilist_detail::SpecificNodeAccess<
412     typename llvm::ilist_detail::compute_node_options<
413         ::mlir::Operation>::type>::getNodePtr(const_pointer N)
414     -> const node_type * {
415   return NodeAccess::getNodePtr<OptionsT>(N);
416 }
417 
418 auto llvm::ilist_detail::SpecificNodeAccess<
419     typename llvm::ilist_detail::compute_node_options<
420         ::mlir::Operation>::type>::getValuePtr(node_type *N) -> pointer {
421   return NodeAccess::getValuePtr<OptionsT>(N);
422 }
423 
424 auto llvm::ilist_detail::SpecificNodeAccess<
425     typename llvm::ilist_detail::compute_node_options<
426         ::mlir::Operation>::type>::getValuePtr(const node_type *N)
427     -> const_pointer {
428   return NodeAccess::getValuePtr<OptionsT>(N);
429 }
430 
431 void llvm::ilist_traits<::mlir::Operation>::deleteNode(Operation *op) {
432   op->destroy();
433 }
434 
435 Block *llvm::ilist_traits<::mlir::Operation>::getContainingBlock() {
436   size_t Offset(size_t(&((Block *)nullptr->*Block::getSublistAccess(nullptr))));
437   iplist<Operation> *Anchor(static_cast<iplist<Operation> *>(this));
438   return reinterpret_cast<Block *>(reinterpret_cast<char *>(Anchor) - Offset);
439 }
440 
441 /// This is a trait method invoked when an operation is added to a block.  We
442 /// keep the block pointer up to date.
443 void llvm::ilist_traits<::mlir::Operation>::addNodeToList(Operation *op) {
444   assert(!op->getBlock() && "already in an operation block!");
445   op->block = getContainingBlock();
446 
447   // Invalidate the order on the operation.
448   op->orderIndex = Operation::kInvalidOrderIdx;
449 }
450 
451 /// This is a trait method invoked when an operation is removed from a block.
452 /// We keep the block pointer up to date.
453 void llvm::ilist_traits<::mlir::Operation>::removeNodeFromList(Operation *op) {
454   assert(op->block && "not already in an operation block!");
455   op->block = nullptr;
456 }
457 
458 /// This is a trait method invoked when an operation is moved from one block
459 /// to another.  We keep the block pointer up to date.
460 void llvm::ilist_traits<::mlir::Operation>::transferNodesFromList(
461     ilist_traits<Operation> &otherList, op_iterator first, op_iterator last) {
462   Block *curParent = getContainingBlock();
463 
464   // Invalidate the ordering of the parent block.
465   curParent->invalidateOpOrder();
466 
467   // If we are transferring operations within the same block, the block
468   // pointer doesn't need to be updated.
469   if (curParent == otherList.getContainingBlock())
470     return;
471 
472   // Update the 'block' member of each operation.
473   for (; first != last; ++first)
474     first->block = curParent;
475 }
476 
477 /// Remove this operation (and its descendants) from its Block and delete
478 /// all of them.
479 void Operation::erase() {
480   if (auto *parent = getBlock())
481     parent->getOperations().erase(this);
482   else
483     destroy();
484 }
485 
486 /// Remove the operation from its parent block, but don't delete it.
487 void Operation::remove() {
488   if (Block *parent = getBlock())
489     parent->getOperations().remove(this);
490 }
491 
492 /// Unlink this operation from its current block and insert it right before
493 /// `existingOp` which may be in the same or another block in the same
494 /// function.
495 void Operation::moveBefore(Operation *existingOp) {
496   moveBefore(existingOp->getBlock(), existingOp->getIterator());
497 }
498 
499 /// Unlink this operation from its current basic block and insert it right
500 /// before `iterator` in the specified basic block.
501 void Operation::moveBefore(Block *block,
502                            llvm::iplist<Operation>::iterator iterator) {
503   block->getOperations().splice(iterator, getBlock()->getOperations(),
504                                 getIterator());
505 }
506 
507 /// Unlink this operation from its current block and insert it right after
508 /// `existingOp` which may be in the same or another block in the same function.
509 void Operation::moveAfter(Operation *existingOp) {
510   moveAfter(existingOp->getBlock(), existingOp->getIterator());
511 }
512 
513 /// Unlink this operation from its current block and insert it right after
514 /// `iterator` in the specified block.
515 void Operation::moveAfter(Block *block,
516                           llvm::iplist<Operation>::iterator iterator) {
517   assert(iterator != block->end() && "cannot move after end of block");
518   moveBefore(&*std::next(iterator));
519 }
520 
521 /// This drops all operand uses from this operation, which is an essential
522 /// step in breaking cyclic dependences between references when they are to
523 /// be deleted.
524 void Operation::dropAllReferences() {
525   for (auto &op : getOpOperands())
526     op.drop();
527 
528   for (auto &region : getRegions())
529     region.dropAllReferences();
530 
531   for (auto &dest : getBlockOperands())
532     dest.drop();
533 }
534 
535 /// This drops all uses of any values defined by this operation or its nested
536 /// regions, wherever they are located.
537 void Operation::dropAllDefinedValueUses() {
538   dropAllUses();
539 
540   for (auto &region : getRegions())
541     for (auto &block : region)
542       block.dropAllDefinedValueUses();
543 }
544 
545 void Operation::setSuccessor(Block *block, unsigned index) {
546   assert(index < getNumSuccessors());
547   getBlockOperands()[index].set(block);
548 }
549 
550 /// Attempt to fold this operation using the Op's registered foldHook.
551 LogicalResult Operation::fold(ArrayRef<Attribute> operands,
552                               SmallVectorImpl<OpFoldResult> &results) {
553   // If we have a registered operation definition matching this one, use it to
554   // try to constant fold the operation.
555   auto *abstractOp = getAbstractOperation();
556   if (abstractOp && succeeded(abstractOp->foldHook(this, operands, results)))
557     return success();
558 
559   // Otherwise, fall back on the dialect hook to handle it.
560   Dialect *dialect = getDialect();
561   if (!dialect)
562     return failure();
563 
564   auto *interface = dialect->getRegisteredInterface<DialectFoldInterface>();
565   if (!interface)
566     return failure();
567 
568   return interface->fold(this, operands, results);
569 }
570 
571 /// Emit an error with the op name prefixed, like "'dim' op " which is
572 /// convenient for verifiers.
573 InFlightDiagnostic Operation::emitOpError(const Twine &message) {
574   return emitError() << "'" << getName() << "' op " << message;
575 }
576 
577 //===----------------------------------------------------------------------===//
578 // Operation Cloning
579 //===----------------------------------------------------------------------===//
580 
581 /// Create a deep copy of this operation but keep the operation regions empty.
582 /// Operands are remapped using `mapper` (if present), and `mapper` is updated
583 /// to contain the results.
584 Operation *Operation::cloneWithoutRegions(BlockAndValueMapping &mapper) {
585   SmallVector<Value, 8> operands;
586   SmallVector<Block *, 2> successors;
587 
588   // Remap the operands.
589   operands.reserve(getNumOperands());
590   for (auto opValue : getOperands())
591     operands.push_back(mapper.lookupOrDefault(opValue));
592 
593   // Remap the successors.
594   successors.reserve(getNumSuccessors());
595   for (Block *successor : getSuccessors())
596     successors.push_back(mapper.lookupOrDefault(successor));
597 
598   // Create the new operation.
599   auto *newOp = create(getLoc(), getName(), getResultTypes(), operands, attrs,
600                        successors, getNumRegions());
601 
602   // Remember the mapping of any results.
603   for (unsigned i = 0, e = getNumResults(); i != e; ++i)
604     mapper.map(getResult(i), newOp->getResult(i));
605 
606   return newOp;
607 }
608 
609 Operation *Operation::cloneWithoutRegions() {
610   BlockAndValueMapping mapper;
611   return cloneWithoutRegions(mapper);
612 }
613 
614 /// Create a deep copy of this operation, remapping any operands that use
615 /// values outside of the operation using the map that is provided (leaving
616 /// them alone if no entry is present).  Replaces references to cloned
617 /// sub-operations to the corresponding operation that is copied, and adds
618 /// those mappings to the map.
619 Operation *Operation::clone(BlockAndValueMapping &mapper) {
620   auto *newOp = cloneWithoutRegions(mapper);
621 
622   // Clone the regions.
623   for (unsigned i = 0; i != numRegions; ++i)
624     getRegion(i).cloneInto(&newOp->getRegion(i), mapper);
625 
626   return newOp;
627 }
628 
629 Operation *Operation::clone() {
630   BlockAndValueMapping mapper;
631   return clone(mapper);
632 }
633 
634 //===----------------------------------------------------------------------===//
635 // OpState trait class.
636 //===----------------------------------------------------------------------===//
637 
638 // The fallback for the parser is to reject the custom assembly form.
639 ParseResult OpState::parse(OpAsmParser &parser, OperationState &result) {
640   return parser.emitError(parser.getNameLoc(), "has no custom assembly form");
641 }
642 
643 // The fallback for the printer is to print in the generic assembly form.
644 void OpState::print(Operation *op, OpAsmPrinter &p) { p.printGenericOp(op); }
645 
646 /// Emit an error about fatal conditions with this operation, reporting up to
647 /// any diagnostic handlers that may be listening.
648 InFlightDiagnostic OpState::emitError(const Twine &message) {
649   return getOperation()->emitError(message);
650 }
651 
652 /// Emit an error with the op name prefixed, like "'dim' op " which is
653 /// convenient for verifiers.
654 InFlightDiagnostic OpState::emitOpError(const Twine &message) {
655   return getOperation()->emitOpError(message);
656 }
657 
658 /// Emit a warning about this operation, reporting up to any diagnostic
659 /// handlers that may be listening.
660 InFlightDiagnostic OpState::emitWarning(const Twine &message) {
661   return getOperation()->emitWarning(message);
662 }
663 
664 /// Emit a remark about this operation, reporting up to any diagnostic
665 /// handlers that may be listening.
666 InFlightDiagnostic OpState::emitRemark(const Twine &message) {
667   return getOperation()->emitRemark(message);
668 }
669 
670 //===----------------------------------------------------------------------===//
671 // Op Trait implementations
672 //===----------------------------------------------------------------------===//
673 
674 OpFoldResult OpTrait::impl::foldIdempotent(Operation *op) {
675   auto *argumentOp = op->getOperand(0).getDefiningOp();
676   if (argumentOp && op->getName() == argumentOp->getName()) {
677     // Replace the outer operation output with the inner operation.
678     return op->getOperand(0);
679   }
680 
681   return {};
682 }
683 
684 OpFoldResult OpTrait::impl::foldInvolution(Operation *op) {
685   auto *argumentOp = op->getOperand(0).getDefiningOp();
686   if (argumentOp && op->getName() == argumentOp->getName()) {
687     // Replace the outer involutions output with inner's input.
688     return argumentOp->getOperand(0);
689   }
690 
691   return {};
692 }
693 
694 LogicalResult OpTrait::impl::verifyZeroOperands(Operation *op) {
695   if (op->getNumOperands() != 0)
696     return op->emitOpError() << "requires zero operands";
697   return success();
698 }
699 
700 LogicalResult OpTrait::impl::verifyOneOperand(Operation *op) {
701   if (op->getNumOperands() != 1)
702     return op->emitOpError() << "requires a single operand";
703   return success();
704 }
705 
706 LogicalResult OpTrait::impl::verifyNOperands(Operation *op,
707                                              unsigned numOperands) {
708   if (op->getNumOperands() != numOperands) {
709     return op->emitOpError() << "expected " << numOperands
710                              << " operands, but found " << op->getNumOperands();
711   }
712   return success();
713 }
714 
715 LogicalResult OpTrait::impl::verifyAtLeastNOperands(Operation *op,
716                                                     unsigned numOperands) {
717   if (op->getNumOperands() < numOperands)
718     return op->emitOpError()
719            << "expected " << numOperands << " or more operands";
720   return success();
721 }
722 
723 /// If this is a vector type, or a tensor type, return the scalar element type
724 /// that it is built around, otherwise return the type unmodified.
725 static Type getTensorOrVectorElementType(Type type) {
726   if (auto vec = type.dyn_cast<VectorType>())
727     return vec.getElementType();
728 
729   // Look through tensor<vector<...>> to find the underlying element type.
730   if (auto tensor = type.dyn_cast<TensorType>())
731     return getTensorOrVectorElementType(tensor.getElementType());
732   return type;
733 }
734 
735 LogicalResult OpTrait::impl::verifyIsIdempotent(Operation *op) {
736   // FIXME: Add back check for no side effects on operation.
737   // Currently adding it would cause the shared library build
738   // to fail since there would be a dependency of IR on SideEffectInterfaces
739   // which is cyclical.
740   return success();
741 }
742 
743 LogicalResult OpTrait::impl::verifyIsInvolution(Operation *op) {
744   // FIXME: Add back check for no side effects on operation.
745   // Currently adding it would cause the shared library build
746   // to fail since there would be a dependency of IR on SideEffectInterfaces
747   // which is cyclical.
748   return success();
749 }
750 
751 LogicalResult
752 OpTrait::impl::verifyOperandsAreSignlessIntegerLike(Operation *op) {
753   for (auto opType : op->getOperandTypes()) {
754     auto type = getTensorOrVectorElementType(opType);
755     if (!type.isSignlessIntOrIndex())
756       return op->emitOpError() << "requires an integer or index type";
757   }
758   return success();
759 }
760 
761 LogicalResult OpTrait::impl::verifyOperandsAreFloatLike(Operation *op) {
762   for (auto opType : op->getOperandTypes()) {
763     auto type = getTensorOrVectorElementType(opType);
764     if (!type.isa<FloatType>())
765       return op->emitOpError("requires a float type");
766   }
767   return success();
768 }
769 
770 LogicalResult OpTrait::impl::verifySameTypeOperands(Operation *op) {
771   // Zero or one operand always have the "same" type.
772   unsigned nOperands = op->getNumOperands();
773   if (nOperands < 2)
774     return success();
775 
776   auto type = op->getOperand(0).getType();
777   for (auto opType : llvm::drop_begin(op->getOperandTypes(), 1))
778     if (opType != type)
779       return op->emitOpError() << "requires all operands to have the same type";
780   return success();
781 }
782 
783 LogicalResult OpTrait::impl::verifyZeroRegion(Operation *op) {
784   if (op->getNumRegions() != 0)
785     return op->emitOpError() << "requires zero regions";
786   return success();
787 }
788 
789 LogicalResult OpTrait::impl::verifyOneRegion(Operation *op) {
790   if (op->getNumRegions() != 1)
791     return op->emitOpError() << "requires one region";
792   return success();
793 }
794 
795 LogicalResult OpTrait::impl::verifyNRegions(Operation *op,
796                                             unsigned numRegions) {
797   if (op->getNumRegions() != numRegions)
798     return op->emitOpError() << "expected " << numRegions << " regions";
799   return success();
800 }
801 
802 LogicalResult OpTrait::impl::verifyAtLeastNRegions(Operation *op,
803                                                    unsigned numRegions) {
804   if (op->getNumRegions() < numRegions)
805     return op->emitOpError() << "expected " << numRegions << " or more regions";
806   return success();
807 }
808 
809 LogicalResult OpTrait::impl::verifyZeroResult(Operation *op) {
810   if (op->getNumResults() != 0)
811     return op->emitOpError() << "requires zero results";
812   return success();
813 }
814 
815 LogicalResult OpTrait::impl::verifyOneResult(Operation *op) {
816   if (op->getNumResults() != 1)
817     return op->emitOpError() << "requires one result";
818   return success();
819 }
820 
821 LogicalResult OpTrait::impl::verifyNResults(Operation *op,
822                                             unsigned numOperands) {
823   if (op->getNumResults() != numOperands)
824     return op->emitOpError() << "expected " << numOperands << " results";
825   return success();
826 }
827 
828 LogicalResult OpTrait::impl::verifyAtLeastNResults(Operation *op,
829                                                    unsigned numOperands) {
830   if (op->getNumResults() < numOperands)
831     return op->emitOpError()
832            << "expected " << numOperands << " or more results";
833   return success();
834 }
835 
836 LogicalResult OpTrait::impl::verifySameOperandsShape(Operation *op) {
837   if (failed(verifyAtLeastNOperands(op, 1)))
838     return failure();
839 
840   if (failed(verifyCompatibleShapes(op->getOperandTypes())))
841     return op->emitOpError() << "requires the same shape for all operands";
842 
843   return success();
844 }
845 
846 LogicalResult OpTrait::impl::verifySameOperandsAndResultShape(Operation *op) {
847   if (failed(verifyAtLeastNOperands(op, 1)) ||
848       failed(verifyAtLeastNResults(op, 1)))
849     return failure();
850 
851   SmallVector<Type, 8> types(op->getOperandTypes());
852   types.append(llvm::to_vector<4>(op->getResultTypes()));
853 
854   if (failed(verifyCompatibleShapes(types)))
855     return op->emitOpError()
856            << "requires the same shape for all operands and results";
857 
858   return success();
859 }
860 
861 LogicalResult OpTrait::impl::verifySameOperandsElementType(Operation *op) {
862   if (failed(verifyAtLeastNOperands(op, 1)))
863     return failure();
864   auto elementType = getElementTypeOrSelf(op->getOperand(0));
865 
866   for (auto operand : llvm::drop_begin(op->getOperands(), 1)) {
867     if (getElementTypeOrSelf(operand) != elementType)
868       return op->emitOpError("requires the same element type for all operands");
869   }
870 
871   return success();
872 }
873 
874 LogicalResult
875 OpTrait::impl::verifySameOperandsAndResultElementType(Operation *op) {
876   if (failed(verifyAtLeastNOperands(op, 1)) ||
877       failed(verifyAtLeastNResults(op, 1)))
878     return failure();
879 
880   auto elementType = getElementTypeOrSelf(op->getResult(0));
881 
882   // Verify result element type matches first result's element type.
883   for (auto result : llvm::drop_begin(op->getResults(), 1)) {
884     if (getElementTypeOrSelf(result) != elementType)
885       return op->emitOpError(
886           "requires the same element type for all operands and results");
887   }
888 
889   // Verify operand's element type matches first result's element type.
890   for (auto operand : op->getOperands()) {
891     if (getElementTypeOrSelf(operand) != elementType)
892       return op->emitOpError(
893           "requires the same element type for all operands and results");
894   }
895 
896   return success();
897 }
898 
899 LogicalResult OpTrait::impl::verifySameOperandsAndResultType(Operation *op) {
900   if (failed(verifyAtLeastNOperands(op, 1)) ||
901       failed(verifyAtLeastNResults(op, 1)))
902     return failure();
903 
904   auto type = op->getResult(0).getType();
905   auto elementType = getElementTypeOrSelf(type);
906   for (auto resultType : llvm::drop_begin(op->getResultTypes())) {
907     if (getElementTypeOrSelf(resultType) != elementType ||
908         failed(verifyCompatibleShape(resultType, type)))
909       return op->emitOpError()
910              << "requires the same type for all operands and results";
911   }
912   for (auto opType : op->getOperandTypes()) {
913     if (getElementTypeOrSelf(opType) != elementType ||
914         failed(verifyCompatibleShape(opType, type)))
915       return op->emitOpError()
916              << "requires the same type for all operands and results";
917   }
918   return success();
919 }
920 
921 LogicalResult OpTrait::impl::verifyIsTerminator(Operation *op) {
922   Block *block = op->getBlock();
923   // Verify that the operation is at the end of the respective parent block.
924   if (!block || &block->back() != op)
925     return op->emitOpError("must be the last operation in the parent block");
926   return success();
927 }
928 
929 static LogicalResult verifyTerminatorSuccessors(Operation *op) {
930   auto *parent = op->getParentRegion();
931 
932   // Verify that the operands lines up with the BB arguments in the successor.
933   for (Block *succ : op->getSuccessors())
934     if (succ->getParent() != parent)
935       return op->emitError("reference to block defined in another region");
936   return success();
937 }
938 
939 LogicalResult OpTrait::impl::verifyZeroSuccessor(Operation *op) {
940   if (op->getNumSuccessors() != 0) {
941     return op->emitOpError("requires 0 successors but found ")
942            << op->getNumSuccessors();
943   }
944   return success();
945 }
946 
947 LogicalResult OpTrait::impl::verifyOneSuccessor(Operation *op) {
948   if (op->getNumSuccessors() != 1) {
949     return op->emitOpError("requires 1 successor but found ")
950            << op->getNumSuccessors();
951   }
952   return verifyTerminatorSuccessors(op);
953 }
954 LogicalResult OpTrait::impl::verifyNSuccessors(Operation *op,
955                                                unsigned numSuccessors) {
956   if (op->getNumSuccessors() != numSuccessors) {
957     return op->emitOpError("requires ")
958            << numSuccessors << " successors but found "
959            << op->getNumSuccessors();
960   }
961   return verifyTerminatorSuccessors(op);
962 }
963 LogicalResult OpTrait::impl::verifyAtLeastNSuccessors(Operation *op,
964                                                       unsigned numSuccessors) {
965   if (op->getNumSuccessors() < numSuccessors) {
966     return op->emitOpError("requires at least ")
967            << numSuccessors << " successors but found "
968            << op->getNumSuccessors();
969   }
970   return verifyTerminatorSuccessors(op);
971 }
972 
973 LogicalResult OpTrait::impl::verifyResultsAreBoolLike(Operation *op) {
974   for (auto resultType : op->getResultTypes()) {
975     auto elementType = getTensorOrVectorElementType(resultType);
976     bool isBoolType = elementType.isInteger(1);
977     if (!isBoolType)
978       return op->emitOpError() << "requires a bool result type";
979   }
980 
981   return success();
982 }
983 
984 LogicalResult OpTrait::impl::verifyResultsAreFloatLike(Operation *op) {
985   for (auto resultType : op->getResultTypes())
986     if (!getTensorOrVectorElementType(resultType).isa<FloatType>())
987       return op->emitOpError() << "requires a floating point type";
988 
989   return success();
990 }
991 
992 LogicalResult
993 OpTrait::impl::verifyResultsAreSignlessIntegerLike(Operation *op) {
994   for (auto resultType : op->getResultTypes())
995     if (!getTensorOrVectorElementType(resultType).isSignlessIntOrIndex())
996       return op->emitOpError() << "requires an integer or index type";
997   return success();
998 }
999 
1000 static LogicalResult verifyValueSizeAttr(Operation *op, StringRef attrName,
1001                                          bool isOperand) {
1002   auto sizeAttr = op->getAttrOfType<DenseIntElementsAttr>(attrName);
1003   if (!sizeAttr)
1004     return op->emitOpError("requires 1D vector attribute '") << attrName << "'";
1005 
1006   auto sizeAttrType = sizeAttr.getType().dyn_cast<VectorType>();
1007   if (!sizeAttrType || sizeAttrType.getRank() != 1 ||
1008       !sizeAttrType.getElementType().isInteger(32))
1009     return op->emitOpError("requires 1D vector of i32 attribute '")
1010            << attrName << "'";
1011 
1012   if (llvm::any_of(sizeAttr.getIntValues(), [](const APInt &element) {
1013         return !element.isNonNegative();
1014       }))
1015     return op->emitOpError("'")
1016            << attrName << "' attribute cannot have negative elements";
1017 
1018   size_t totalCount = std::accumulate(
1019       sizeAttr.begin(), sizeAttr.end(), 0,
1020       [](unsigned all, APInt one) { return all + one.getZExtValue(); });
1021 
1022   if (isOperand && totalCount != op->getNumOperands())
1023     return op->emitOpError("operand count (")
1024            << op->getNumOperands() << ") does not match with the total size ("
1025            << totalCount << ") specified in attribute '" << attrName << "'";
1026   else if (!isOperand && totalCount != op->getNumResults())
1027     return op->emitOpError("result count (")
1028            << op->getNumResults() << ") does not match with the total size ("
1029            << totalCount << ") specified in attribute '" << attrName << "'";
1030   return success();
1031 }
1032 
1033 LogicalResult OpTrait::impl::verifyOperandSizeAttr(Operation *op,
1034                                                    StringRef attrName) {
1035   return verifyValueSizeAttr(op, attrName, /*isOperand=*/true);
1036 }
1037 
1038 LogicalResult OpTrait::impl::verifyResultSizeAttr(Operation *op,
1039                                                   StringRef attrName) {
1040   return verifyValueSizeAttr(op, attrName, /*isOperand=*/false);
1041 }
1042 
1043 LogicalResult OpTrait::impl::verifyNoRegionArguments(Operation *op) {
1044   for (Region &region : op->getRegions()) {
1045     if (region.empty())
1046       continue;
1047 
1048     if (region.getNumArguments() != 0) {
1049       if (op->getNumRegions() > 1)
1050         return op->emitOpError("region #")
1051                << region.getRegionNumber() << " should have no arguments";
1052       else
1053         return op->emitOpError("region should have no arguments");
1054     }
1055   }
1056   return success();
1057 }
1058 
1059 LogicalResult OpTrait::impl::verifyElementwise(Operation *op) {
1060   auto isMappableType = [](Type type) {
1061     return type.isa<VectorType, TensorType>();
1062   };
1063   auto resultMappableTypes = llvm::to_vector<1>(
1064       llvm::make_filter_range(op->getResultTypes(), isMappableType));
1065   auto operandMappableTypes = llvm::to_vector<2>(
1066       llvm::make_filter_range(op->getOperandTypes(), isMappableType));
1067 
1068   // If the op only has scalar operand/result types, then we have nothing to
1069   // check.
1070   if (resultMappableTypes.empty() && operandMappableTypes.empty())
1071     return success();
1072 
1073   if (!resultMappableTypes.empty() && operandMappableTypes.empty())
1074     return op->emitOpError("if a result is non-scalar, then at least one "
1075                            "operand must be non-scalar");
1076 
1077   assert(!operandMappableTypes.empty());
1078 
1079   if (resultMappableTypes.empty())
1080     return op->emitOpError("if an operand is non-scalar, then there must be at "
1081                            "least one non-scalar result");
1082 
1083   if (resultMappableTypes.size() != op->getNumResults())
1084     return op->emitOpError(
1085         "if an operand is non-scalar, then all results must be non-scalar");
1086 
1087   SmallVector<Type, 4> types = llvm::to_vector<2>(
1088       llvm::concat<Type>(operandMappableTypes, resultMappableTypes));
1089   TypeID expectedBaseTy = types.front().getTypeID();
1090   if (!llvm::all_of(types,
1091                     [&](Type t) { return t.getTypeID() == expectedBaseTy; }) ||
1092       failed(verifyCompatibleShapes(types))) {
1093     return op->emitOpError() << "all non-scalar operands/results must have the "
1094                                 "same shape and base type";
1095   }
1096 
1097   return success();
1098 }
1099 
1100 /// Check for any values used by operations regions attached to the
1101 /// specified "IsIsolatedFromAbove" operation defined outside of it.
1102 LogicalResult OpTrait::impl::verifyIsIsolatedFromAbove(Operation *isolatedOp) {
1103   assert(isolatedOp->hasTrait<OpTrait::IsIsolatedFromAbove>() &&
1104          "Intended to check IsolatedFromAbove ops");
1105 
1106   // List of regions to analyze.  Each region is processed independently, with
1107   // respect to the common `limit` region, so we can look at them in any order.
1108   // Therefore, use a simple vector and push/pop back the current region.
1109   SmallVector<Region *, 8> pendingRegions;
1110   for (auto &region : isolatedOp->getRegions()) {
1111     pendingRegions.push_back(&region);
1112 
1113     // Traverse all operations in the region.
1114     while (!pendingRegions.empty()) {
1115       for (Operation &op : pendingRegions.pop_back_val()->getOps()) {
1116         for (Value operand : op.getOperands()) {
1117           // operand should be non-null here if the IR is well-formed. But
1118           // we don't assert here as this function is called from the verifier
1119           // and so could be called on invalid IR.
1120           if (!operand)
1121             return op.emitOpError("operation's operand is null");
1122 
1123           // Check that any value that is used by an operation is defined in the
1124           // same region as either an operation result.
1125           auto *operandRegion = operand.getParentRegion();
1126           if (!region.isAncestor(operandRegion)) {
1127             return op.emitOpError("using value defined outside the region")
1128                        .attachNote(isolatedOp->getLoc())
1129                    << "required by region isolation constraints";
1130           }
1131         }
1132 
1133         // Schedule any regions in the operation for further checking.  Don't
1134         // recurse into other IsolatedFromAbove ops, because they will check
1135         // themselves.
1136         if (op.getNumRegions() &&
1137             !op.hasTrait<OpTrait::IsIsolatedFromAbove>()) {
1138           for (Region &subRegion : op.getRegions())
1139             pendingRegions.push_back(&subRegion);
1140         }
1141       }
1142     }
1143   }
1144 
1145   return success();
1146 }
1147 
1148 bool OpTrait::hasElementwiseMappableTraits(Operation *op) {
1149   return op->hasTrait<Elementwise>() && op->hasTrait<Scalarizable>() &&
1150          op->hasTrait<Vectorizable>() && op->hasTrait<Tensorizable>();
1151 }
1152 
1153 //===----------------------------------------------------------------------===//
1154 // BinaryOp implementation
1155 //===----------------------------------------------------------------------===//
1156 
1157 // These functions are out-of-line implementations of the methods in BinaryOp,
1158 // which avoids them being template instantiated/duplicated.
1159 
1160 void impl::buildBinaryOp(OpBuilder &builder, OperationState &result, Value lhs,
1161                          Value rhs) {
1162   assert(lhs.getType() == rhs.getType());
1163   result.addOperands({lhs, rhs});
1164   result.types.push_back(lhs.getType());
1165 }
1166 
1167 ParseResult impl::parseOneResultSameOperandTypeOp(OpAsmParser &parser,
1168                                                   OperationState &result) {
1169   SmallVector<OpAsmParser::OperandType, 2> ops;
1170   Type type;
1171   return failure(parser.parseOperandList(ops) ||
1172                  parser.parseOptionalAttrDict(result.attributes) ||
1173                  parser.parseColonType(type) ||
1174                  parser.resolveOperands(ops, type, result.operands) ||
1175                  parser.addTypeToList(type, result.types));
1176 }
1177 
1178 void impl::printOneResultOp(Operation *op, OpAsmPrinter &p) {
1179   assert(op->getNumResults() == 1 && "op should have one result");
1180 
1181   // If not all the operand and result types are the same, just use the
1182   // generic assembly form to avoid omitting information in printing.
1183   auto resultType = op->getResult(0).getType();
1184   if (llvm::any_of(op->getOperandTypes(),
1185                    [&](Type type) { return type != resultType; })) {
1186     p.printGenericOp(op);
1187     return;
1188   }
1189 
1190   p << op->getName() << ' ';
1191   p.printOperands(op->getOperands());
1192   p.printOptionalAttrDict(op->getAttrs());
1193   // Now we can output only one type for all operands and the result.
1194   p << " : " << resultType;
1195 }
1196 
1197 //===----------------------------------------------------------------------===//
1198 // CastOp implementation
1199 //===----------------------------------------------------------------------===//
1200 
1201 /// Attempt to fold the given cast operation.
1202 LogicalResult
1203 impl::foldCastInterfaceOp(Operation *op, ArrayRef<Attribute> attrOperands,
1204                           SmallVectorImpl<OpFoldResult> &foldResults) {
1205   OperandRange operands = op->getOperands();
1206   if (operands.empty())
1207     return failure();
1208   ResultRange results = op->getResults();
1209 
1210   // Check for the case where the input and output types match 1-1.
1211   if (operands.getTypes() == results.getTypes()) {
1212     foldResults.append(operands.begin(), operands.end());
1213     return success();
1214   }
1215 
1216   return failure();
1217 }
1218 
1219 /// Attempt to verify the given cast operation.
1220 LogicalResult impl::verifyCastInterfaceOp(
1221     Operation *op, function_ref<bool(TypeRange, TypeRange)> areCastCompatible) {
1222   auto resultTypes = op->getResultTypes();
1223   if (llvm::empty(resultTypes))
1224     return op->emitOpError()
1225            << "expected at least one result for cast operation";
1226 
1227   auto operandTypes = op->getOperandTypes();
1228   if (!areCastCompatible(operandTypes, resultTypes)) {
1229     InFlightDiagnostic diag = op->emitOpError("operand type");
1230     if (llvm::empty(operandTypes))
1231       diag << "s []";
1232     else if (llvm::size(operandTypes) == 1)
1233       diag << " " << *operandTypes.begin();
1234     else
1235       diag << "s " << operandTypes;
1236     return diag << " and result type" << (resultTypes.size() == 1 ? " " : "s ")
1237                 << resultTypes << " are cast incompatible";
1238   }
1239 
1240   return success();
1241 }
1242 
1243 void impl::buildCastOp(OpBuilder &builder, OperationState &result, Value source,
1244                        Type destType) {
1245   result.addOperands(source);
1246   result.addTypes(destType);
1247 }
1248 
1249 ParseResult impl::parseCastOp(OpAsmParser &parser, OperationState &result) {
1250   OpAsmParser::OperandType srcInfo;
1251   Type srcType, dstType;
1252   return failure(parser.parseOperand(srcInfo) ||
1253                  parser.parseOptionalAttrDict(result.attributes) ||
1254                  parser.parseColonType(srcType) ||
1255                  parser.resolveOperand(srcInfo, srcType, result.operands) ||
1256                  parser.parseKeywordType("to", dstType) ||
1257                  parser.addTypeToList(dstType, result.types));
1258 }
1259 
1260 void impl::printCastOp(Operation *op, OpAsmPrinter &p) {
1261   p << op->getName() << ' ' << op->getOperand(0);
1262   p.printOptionalAttrDict(op->getAttrs());
1263   p << " : " << op->getOperand(0).getType() << " to "
1264     << op->getResult(0).getType();
1265 }
1266 
1267 Value impl::foldCastOp(Operation *op) {
1268   // Identity cast
1269   if (op->getOperand(0).getType() == op->getResult(0).getType())
1270     return op->getOperand(0);
1271   return nullptr;
1272 }
1273 
1274 LogicalResult
1275 impl::verifyCastOp(Operation *op,
1276                    function_ref<bool(Type, Type)> areCastCompatible) {
1277   auto opType = op->getOperand(0).getType();
1278   auto resType = op->getResult(0).getType();
1279   if (!areCastCompatible(opType, resType))
1280     return op->emitError("operand type ")
1281            << opType << " and result type " << resType
1282            << " are cast incompatible";
1283 
1284   return success();
1285 }
1286 
1287 //===----------------------------------------------------------------------===//
1288 // Misc. utils
1289 //===----------------------------------------------------------------------===//
1290 
1291 /// Insert an operation, generated by `buildTerminatorOp`, at the end of the
1292 /// region's only block if it does not have a terminator already. If the region
1293 /// is empty, insert a new block first. `buildTerminatorOp` should return the
1294 /// terminator operation to insert.
1295 void impl::ensureRegionTerminator(
1296     Region &region, OpBuilder &builder, Location loc,
1297     function_ref<Operation *(OpBuilder &, Location)> buildTerminatorOp) {
1298   OpBuilder::InsertionGuard guard(builder);
1299   if (region.empty())
1300     builder.createBlock(&region);
1301 
1302   Block &block = region.back();
1303   if (!block.empty() && block.back().hasTrait<OpTrait::IsTerminator>())
1304     return;
1305 
1306   builder.setInsertionPointToEnd(&block);
1307   builder.insert(buildTerminatorOp(builder, loc));
1308 }
1309 
1310 /// Create a simple OpBuilder and forward to the OpBuilder version of this
1311 /// function.
1312 void impl::ensureRegionTerminator(
1313     Region &region, Builder &builder, Location loc,
1314     function_ref<Operation *(OpBuilder &, Location)> buildTerminatorOp) {
1315   OpBuilder opBuilder(builder.getContext());
1316   ensureRegionTerminator(region, opBuilder, loc, buildTerminatorOp);
1317 }
1318 
1319 //===----------------------------------------------------------------------===//
1320 // UseIterator
1321 //===----------------------------------------------------------------------===//
1322 
1323 Operation::UseIterator::UseIterator(Operation *op, bool end)
1324     : op(op), res(end ? op->result_end() : op->result_begin()) {
1325   // Only initialize current use if there are results/can be uses.
1326   if (op->getNumResults())
1327     skipOverResultsWithNoUsers();
1328 }
1329 
1330 Operation::UseIterator &Operation::UseIterator::operator++() {
1331   // We increment over uses, if we reach the last use then move to next
1332   // result.
1333   if (use != (*res).use_end())
1334     ++use;
1335   if (use == (*res).use_end()) {
1336     ++res;
1337     skipOverResultsWithNoUsers();
1338   }
1339   return *this;
1340 }
1341 
1342 void Operation::UseIterator::skipOverResultsWithNoUsers() {
1343   while (res != op->result_end() && (*res).use_empty())
1344     ++res;
1345 
1346   // If we are at the last result, then set use to first use of
1347   // first result (sentinel value used for end).
1348   if (res == op->result_end())
1349     use = {};
1350   else
1351     use = (*res).use_begin();
1352 }
1353