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