76 lines
2.7 KiB
C++
76 lines
2.7 KiB
C++
|
//===- DIExpressionRewriter.cpp - Rewriter for DIExpression operators -----===//
|
||
|
|
//
|
||
|
|
// 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/Dialect/LLVMIR/Transforms/DIExpressionRewriter.h"
|
||
|
|
#include "mlir/Transforms/GreedyPatternRewriteDriver.h"
|
||
|
|
#include "llvm/Support/Debug.h"
|
||
|
|
|
||
|
|
using namespace mlir;
|
||
|
|
using namespace LLVM;
|
||
|
|
|
||
|
|
#define DEBUG_TYPE "llvm-di-expression-simplifier"
|
||
|
|
|
||
|
|
//===----------------------------------------------------------------------===//
|
||
|
|
// DIExpressionRewriter
|
||
|
|
//===----------------------------------------------------------------------===//
|
||
|
|
|
||
|
|
void DIExpressionRewriter::addPattern(
|
||
|
|
std::unique_ptr<ExprRewritePattern> pattern) {
|
||
|
|
patterns.emplace_back(std::move(pattern));
|
||
|
|
}
|
||
|
|
|
||
|
|
DIExpressionAttr
|
||
|
|
DIExpressionRewriter::simplify(DIExpressionAttr expr,
|
||
|
|
std::optional<uint64_t> maxNumRewrites) const {
|
||
|
|
ArrayRef<OperatorT> operators = expr.getOperations();
|
||
|
|
|
||
|
|
// `inputs` contains the unprocessed postfix of operators.
|
||
|
|
// `result` contains the already finalized prefix of operators.
|
||
|
|
// Invariant: concat(result, inputs) is equivalent to `operators` after some
|
||
|
|
// application of the rewrite patterns.
|
||
|
|
// Using a deque for inputs so that we have efficient front insertion and
|
||
|
|
// removal. Random access is not necessary for patterns.
|
||
|
|
std::deque<OperatorT> inputs(operators.begin(), operators.end());
|
||
|
|
SmallVector<OperatorT> result;
|
||
|
|
|
||
|
|
uint64_t numRewrites = 0;
|
||
|
|
while (!inputs.empty() &&
|
||
|
|
(!maxNumRewrites || numRewrites < *maxNumRewrites)) {
|
||
|
|
bool foundMatch = false;
|
||
|
|
for (const std::unique_ptr<ExprRewritePattern> &pattern : patterns) {
|
||
|
|
ExprRewritePattern::OpIterT matchEnd = pattern->match(inputs);
|
||
|
|
if (matchEnd == inputs.begin())
|
||
|
|
continue;
|
||
|
|
|
||
|
|
foundMatch = true;
|
||
|
|
SmallVector<OperatorT> replacement =
|
||
|
|
pattern->replace(llvm::make_range(inputs.cbegin(), matchEnd));
|
||
|
|
inputs.erase(inputs.begin(), matchEnd);
|
||
|
|
inputs.insert(inputs.begin(), replacement.begin(), replacement.end());
|
||
|
|
++numRewrites;
|
||
|
|
break;
|
||
|
|
}
|
||
|
|
|
||
|
|
if (!foundMatch) {
|
||
|
|
// If no match, pass along the current operator.
|
||
|
|
result.push_back(inputs.front());
|
||
|
|
inputs.pop_front();
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
if (maxNumRewrites && numRewrites >= *maxNumRewrites) {
|
||
|
|
LLVM_DEBUG(llvm::dbgs()
|
||
|
|
<< "LLVMDIExpressionSimplifier exceeded max num rewrites ("
|
||
|
|
<< maxNumRewrites << ")\n");
|
||
|
|
// Skip rewriting the rest.
|
||
|
|
result.append(inputs.begin(), inputs.end());
|
||
|
|
}
|
||
|
|
|
||
|
|
return LLVM::DIExpressionAttr::get(expr.getContext(), result);
|
||
|
|
}
|