MLIR  19.0.0git
LoopLikeInterface.cpp
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1 //===- LoopLikeInterface.cpp - Loop-like operations in MLIR ---------------===//
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 
10 
12 #include "llvm/ADT/DenseSet.h"
13 
14 using namespace mlir;
15 
16 /// Include the definitions of the loop-like interfaces.
17 #include "mlir/Interfaces/LoopLikeInterface.cpp.inc"
18 
19 bool LoopLikeOpInterface::blockIsInLoop(Block *block) {
20  Operation *parent = block->getParentOp();
21 
22  // The block could be inside a loop-like operation
23  if (isa<LoopLikeOpInterface>(parent) ||
24  parent->getParentOfType<LoopLikeOpInterface>())
25  return true;
26 
27  // This block might be nested inside another block, which is in a loop
28  if (!isa<FunctionOpInterface>(parent))
29  if (mlir::Block *parentBlock = parent->getBlock())
30  if (blockIsInLoop(parentBlock))
31  return true;
32 
33  // Or the block could be inside a control flow graph loop:
34  // A block is in a control flow graph loop if it can reach itself in a graph
35  // traversal
36  DenseSet<Block *> visited;
38  stack.push_back(block);
39  while (!stack.empty()) {
40  Block *current = stack.pop_back_val();
41  auto [it, inserted] = visited.insert(current);
42  if (!inserted) {
43  // loop detected
44  if (current == block)
45  return true;
46  continue;
47  }
48 
49  stack.reserve(stack.size() + current->getNumSuccessors());
50  for (Block *successor : current->getSuccessors())
51  stack.push_back(successor);
52  }
53  return false;
54 }
55 
57  // Note: These invariants are also verified by the RegionBranchOpInterface,
58  // but the LoopLikeOpInterface provides better error messages.
59  auto loopLikeOp = cast<LoopLikeOpInterface>(op);
60 
61  // Verify number of inits/iter_args/yielded values/loop results.
62  if (loopLikeOp.getInits().size() != loopLikeOp.getRegionIterArgs().size())
63  return op->emitOpError("different number of inits and region iter_args: ")
64  << loopLikeOp.getInits().size()
65  << " != " << loopLikeOp.getRegionIterArgs().size();
66  if (!loopLikeOp.getYieldedValues().empty() &&
67  loopLikeOp.getRegionIterArgs().size() !=
68  loopLikeOp.getYieldedValues().size())
69  return op->emitOpError(
70  "different number of region iter_args and yielded values: ")
71  << loopLikeOp.getRegionIterArgs().size()
72  << " != " << loopLikeOp.getYieldedValues().size();
73  if (loopLikeOp.getLoopResults() && loopLikeOp.getLoopResults()->size() !=
74  loopLikeOp.getRegionIterArgs().size())
75  return op->emitOpError(
76  "different number of loop results and region iter_args: ")
77  << loopLikeOp.getLoopResults()->size()
78  << " != " << loopLikeOp.getRegionIterArgs().size();
79 
80  // Verify types of inits/iter_args/yielded values/loop results.
81  int64_t i = 0;
82  auto yieldedValues = loopLikeOp.getYieldedValues();
83  for (const auto [index, init, regionIterArg] :
84  llvm::enumerate(loopLikeOp.getInits(), loopLikeOp.getRegionIterArgs())) {
85  if (init.getType() != regionIterArg.getType())
86  return op->emitOpError(std::to_string(index))
87  << "-th init and " << index
88  << "-th region iter_arg have different type: " << init.getType()
89  << " != " << regionIterArg.getType();
90  if (!yieldedValues.empty()) {
91  if (regionIterArg.getType() != yieldedValues[index].getType())
92  return op->emitOpError(std::to_string(index))
93  << "-th region iter_arg and " << index
94  << "-th yielded value have different type: "
95  << regionIterArg.getType()
96  << " != " << yieldedValues[index].getType();
97  }
98  ++i;
99  }
100  i = 0;
101  if (loopLikeOp.getLoopResults()) {
102  for (const auto it : llvm::zip_equal(loopLikeOp.getRegionIterArgs(),
103  *loopLikeOp.getLoopResults())) {
104  if (std::get<0>(it).getType() != std::get<1>(it).getType())
105  return op->emitOpError(std::to_string(i))
106  << "-th region iter_arg and " << i
107  << "-th loop result have different type: "
108  << std::get<0>(it).getType()
109  << " != " << std::get<1>(it).getType();
110  }
111  ++i;
112  }
113 
114  return success();
115 }
Block represents an ordered list of Operations.
Definition: Block.h:30
unsigned getNumSuccessors()
Definition: Block.cpp:254
SuccessorRange getSuccessors()
Definition: Block.h:264
Operation * getParentOp()
Returns the closest surrounding operation that contains this block.
Definition: Block.cpp:30
Operation is the basic unit of execution within MLIR.
Definition: Operation.h:88
Block * getBlock()
Returns the operation block that contains this operation.
Definition: Operation.h:213
OpTy getParentOfType()
Return the closest surrounding parent operation that is of type 'OpTy'.
Definition: Operation.h:238
InFlightDiagnostic emitOpError(const Twine &message={})
Emit an error with the op name prefixed, like "'dim' op " which is convenient for verifiers.
Definition: Operation.cpp:671
constexpr void enumerate(std::tuple< Tys... > &tuple, CallbackT &&callback)
Definition: Matchers.h:285
LogicalResult verifyLoopLikeOpInterface(Operation *op)
Verify invariants of the LoopLikeOpInterface.
Include the generated interface declarations.
LogicalResult success(bool isSuccess=true)
Utility function to generate a LogicalResult.
Definition: LogicalResult.h:56
This class represents an efficient way to signal success or failure.
Definition: LogicalResult.h:26