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//===- PatternMatch.cpp - Base classes for pattern match ------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
#include "mlir/IR/PatternMatch.h"
#include "mlir/IR/BlockAndValueMapping.h"
using namespace mlir;
//===----------------------------------------------------------------------===//
// PatternBenefit
//===----------------------------------------------------------------------===//
PatternBenefit::PatternBenefit(unsigned benefit) : representation(benefit) {
assert(representation == benefit && benefit != ImpossibleToMatchSentinel &&
"This pattern match benefit is too large to represent");
}
unsigned short PatternBenefit::getBenefit() const {
assert(!isImpossibleToMatch() && "Pattern doesn't match");
return representation;
}
//===----------------------------------------------------------------------===//
// Pattern
//===----------------------------------------------------------------------===//
Pattern::Pattern(StringRef rootName, PatternBenefit benefit,
MLIRContext *context)
: rootKind(OperationName(rootName, context)), benefit(benefit) {}
Pattern::Pattern(PatternBenefit benefit, MatchAnyOpTypeTag tag)
: benefit(benefit) {}
Pattern::Pattern(StringRef rootName, ArrayRef<StringRef> generatedNames,
PatternBenefit benefit, MLIRContext *context)
: Pattern(rootName, benefit, context) {
generatedOps.reserve(generatedNames.size());
std::transform(generatedNames.begin(), generatedNames.end(),
std::back_inserter(generatedOps), [context](StringRef name) {
return OperationName(name, context);
});
}
Pattern::Pattern(ArrayRef<StringRef> generatedNames, PatternBenefit benefit,
MLIRContext *context, MatchAnyOpTypeTag tag)
: Pattern(benefit, tag) {
generatedOps.reserve(generatedNames.size());
std::transform(generatedNames.begin(), generatedNames.end(),
std::back_inserter(generatedOps), [context](StringRef name) {
return OperationName(name, context);
});
}
//===----------------------------------------------------------------------===//
// RewritePattern
//===----------------------------------------------------------------------===//
void RewritePattern::rewrite(Operation *op, PatternRewriter &rewriter) const {
llvm_unreachable("need to implement either matchAndRewrite or one of the "
"rewrite functions!");
}
LogicalResult RewritePattern::match(Operation *op) const {
llvm_unreachable("need to implement either match or matchAndRewrite!");
}
/// Out-of-line vtable anchor.
void RewritePattern::anchor() {}
//===----------------------------------------------------------------------===//
// PDLValue
//===----------------------------------------------------------------------===//
void PDLValue::print(raw_ostream &os) {
if (!impl) {
os << "<Null-PDLValue>";
return;
}
if (Value val = impl.dyn_cast<Value>()) {
os << val;
return;
}
AttrOpTypeImplT aotImpl = impl.get<AttrOpTypeImplT>();
if (Attribute attr = aotImpl.dyn_cast<Attribute>())
os << attr;
else if (Operation *op = aotImpl.dyn_cast<Operation *>())
os << *op;
else
os << aotImpl.get<Type>();
}
//===----------------------------------------------------------------------===//
// PDLPatternModule
//===----------------------------------------------------------------------===//
void PDLPatternModule::mergeIn(PDLPatternModule &&other) {
// Ignore the other module if it has no patterns.
if (!other.pdlModule)
return;
// Steal the other state if we have no patterns.
if (!pdlModule) {
constraintFunctions = std::move(other.constraintFunctions);
createFunctions = std::move(other.createFunctions);
rewriteFunctions = std::move(other.rewriteFunctions);
pdlModule = std::move(other.pdlModule);
return;
}
// Steal the functions of the other module.
for (auto &it : constraintFunctions)
registerConstraintFunction(it.first(), std::move(it.second));
for (auto &it : createFunctions)
registerCreateFunction(it.first(), std::move(it.second));
for (auto &it : rewriteFunctions)
registerRewriteFunction(it.first(), std::move(it.second));
// Merge the pattern operations from the other module into this one.
Block *block = pdlModule->getBody();
block->getTerminator()->erase();
block->getOperations().splice(block->end(),
other.pdlModule->getBody()->getOperations());
}
//===----------------------------------------------------------------------===//
// Function Registry
void PDLPatternModule::registerConstraintFunction(
StringRef name, PDLConstraintFunction constraintFn) {
auto it = constraintFunctions.try_emplace(name, std::move(constraintFn));
(void)it;
assert(it.second &&
"constraint with the given name has already been registered");
}
void PDLPatternModule::registerCreateFunction(StringRef name,
PDLCreateFunction createFn) {
auto it = createFunctions.try_emplace(name, std::move(createFn));
(void)it;
assert(it.second && "native create function with the given name has "
"already been registered");
}
void PDLPatternModule::registerRewriteFunction(StringRef name,
PDLRewriteFunction rewriteFn) {
auto it = rewriteFunctions.try_emplace(name, std::move(rewriteFn));
(void)it;
assert(it.second && "native rewrite function with the given name has "
"already been registered");
}
//===----------------------------------------------------------------------===//
// PatternRewriter
//===----------------------------------------------------------------------===//
PatternRewriter::~PatternRewriter() {
// Out of line to provide a vtable anchor for the class.
}
/// This method performs the final replacement for a pattern, where the
/// results of the operation are updated to use the specified list of SSA
/// values.
void PatternRewriter::replaceOp(Operation *op, ValueRange newValues) {
// Notify the rewriter subclass that we're about to replace this root.
notifyRootReplaced(op);
assert(op->getNumResults() == newValues.size() &&
"incorrect # of replacement values");
op->replaceAllUsesWith(newValues);
notifyOperationRemoved(op);
op->erase();
}
/// This method erases an operation that is known to have no uses. The uses of
/// the given operation *must* be known to be dead.
void PatternRewriter::eraseOp(Operation *op) {
assert(op->use_empty() && "expected 'op' to have no uses");
notifyOperationRemoved(op);
op->erase();
}
void PatternRewriter::eraseBlock(Block *block) {
for (auto &op : llvm::make_early_inc_range(llvm::reverse(*block))) {
assert(op.use_empty() && "expected 'op' to have no uses");
eraseOp(&op);
}
block->erase();
}
/// Merge the operations of block 'source' into the end of block 'dest'.
/// 'source's predecessors must be empty or only contain 'dest`.
/// 'argValues' is used to replace the block arguments of 'source' after
/// merging.
void PatternRewriter::mergeBlocks(Block *source, Block *dest,
ValueRange argValues) {
assert(llvm::all_of(source->getPredecessors(),
[dest](Block *succ) { return succ == dest; }) &&
"expected 'source' to have no predecessors or only 'dest'");
assert(argValues.size() == source->getNumArguments() &&
"incorrect # of argument replacement values");
// Replace all of the successor arguments with the provided values.
for (auto it : llvm::zip(source->getArguments(), argValues))
std::get<0>(it).replaceAllUsesWith(std::get<1>(it));
// Splice the operations of the 'source' block into the 'dest' block and erase
// it.
dest->getOperations().splice(dest->end(), source->getOperations());
source->dropAllUses();
source->erase();
}
// Merge the operations of block 'source' before the operation 'op'. Source
// block should not have existing predecessors or successors.
void PatternRewriter::mergeBlockBefore(Block *source, Operation *op,
ValueRange argValues) {
assert(source->hasNoPredecessors() &&
"expected 'source' to have no predecessors");
assert(source->hasNoSuccessors() &&
"expected 'source' to have no successors");
// Split the block containing 'op' into two, one containing all operations
// before 'op' (prologue) and another (epilogue) containing 'op' and all
// operations after it.
Block *prologue = op->getBlock();
Block *epilogue = splitBlock(prologue, op->getIterator());
// Merge the source block at the end of the prologue.
mergeBlocks(source, prologue, argValues);
// Merge the epilogue at the end the prologue.
mergeBlocks(epilogue, prologue);
}
/// Split the operations starting at "before" (inclusive) out of the given
/// block into a new block, and return it.
Block *PatternRewriter::splitBlock(Block *block, Block::iterator before) {
return block->splitBlock(before);
}
/// 'op' and 'newOp' are known to have the same number of results, replace the
/// uses of op with uses of newOp
void PatternRewriter::replaceOpWithResultsOfAnotherOp(Operation *op,
Operation *newOp) {
assert(op->getNumResults() == newOp->getNumResults() &&
"replacement op doesn't match results of original op");
if (op->getNumResults() == 1)
return replaceOp(op, newOp->getResult(0));
return replaceOp(op, newOp->getResults());
}
/// Move the blocks that belong to "region" before the given position in
/// another region. The two regions must be different. The caller is in
/// charge to update create the operation transferring the control flow to the
/// region and pass it the correct block arguments.
void PatternRewriter::inlineRegionBefore(Region &region, Region &parent,
Region::iterator before) {
parent.getBlocks().splice(before, region.getBlocks());
}
void PatternRewriter::inlineRegionBefore(Region &region, Block *before) {
inlineRegionBefore(region, *before->getParent(), before->getIterator());
}
/// Clone the blocks that belong to "region" before the given position in
/// another region "parent". The two regions must be different. The caller is
/// responsible for creating or updating the operation transferring flow of
/// control to the region and passing it the correct block arguments.
void PatternRewriter::cloneRegionBefore(Region &region, Region &parent,
Region::iterator before,
BlockAndValueMapping &mapping) {
region.cloneInto(&parent, before, mapping);
}
void PatternRewriter::cloneRegionBefore(Region &region, Region &parent,
Region::iterator before) {
BlockAndValueMapping mapping;
cloneRegionBefore(region, parent, before, mapping);
}
void PatternRewriter::cloneRegionBefore(Region &region, Block *before) {
cloneRegionBefore(region, *before->getParent(), before->getIterator());
}