123 lines
4.3 KiB
C++
123 lines
4.3 KiB
C++
//===- TestIntRangeInference.cpp - Create consts from range inference ---===//
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//
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// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
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// See https://llvm.org/LICENSE.txt for license information.
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// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
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//
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//===----------------------------------------------------------------------===//
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// TODO: This pass is needed to test integer range inference until that
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// functionality has been integrated into SCCP.
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//===----------------------------------------------------------------------===//
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#include "mlir/Analysis/DataFlow/DeadCodeAnalysis.h"
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#include "mlir/Analysis/DataFlow/IntegerRangeAnalysis.h"
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#include "mlir/Interfaces/SideEffectInterfaces.h"
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#include "mlir/Pass/Pass.h"
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#include "mlir/Pass/PassRegistry.h"
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#include "mlir/Support/TypeID.h"
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#include "mlir/Transforms/FoldUtils.h"
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using namespace mlir;
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using namespace mlir::dataflow;
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/// Patterned after SCCP
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static LogicalResult replaceWithConstant(DataFlowSolver &solver, OpBuilder &b,
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OperationFolder &folder, Value value) {
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auto *maybeInferredRange =
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solver.lookupState<IntegerValueRangeLattice>(value);
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if (!maybeInferredRange || maybeInferredRange->getValue().isUninitialized())
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return failure();
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const ConstantIntRanges &inferredRange =
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maybeInferredRange->getValue().getValue();
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Optional<APInt> maybeConstValue = inferredRange.getConstantValue();
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if (!maybeConstValue.has_value())
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return failure();
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Operation *maybeDefiningOp = value.getDefiningOp();
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Dialect *valueDialect =
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maybeDefiningOp ? maybeDefiningOp->getDialect()
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: value.getParentRegion()->getParentOp()->getDialect();
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Attribute constAttr = b.getIntegerAttr(value.getType(), *maybeConstValue);
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Value constant = folder.getOrCreateConstant(b, valueDialect, constAttr,
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value.getType(), value.getLoc());
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if (!constant)
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return failure();
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value.replaceAllUsesWith(constant);
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return success();
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}
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static void rewrite(DataFlowSolver &solver, MLIRContext *context,
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MutableArrayRef<Region> initialRegions) {
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SmallVector<Block *> worklist;
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auto addToWorklist = [&](MutableArrayRef<Region> regions) {
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for (Region ®ion : regions)
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for (Block &block : llvm::reverse(region))
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worklist.push_back(&block);
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};
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OpBuilder builder(context);
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OperationFolder folder(context);
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addToWorklist(initialRegions);
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while (!worklist.empty()) {
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Block *block = worklist.pop_back_val();
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for (Operation &op : llvm::make_early_inc_range(*block)) {
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builder.setInsertionPoint(&op);
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// Replace any result with constants.
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bool replacedAll = op.getNumResults() != 0;
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for (Value res : op.getResults())
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replacedAll &=
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succeeded(replaceWithConstant(solver, builder, folder, res));
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// If all of the results of the operation were replaced, try to erase
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// the operation completely.
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if (replacedAll && wouldOpBeTriviallyDead(&op)) {
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assert(op.use_empty() && "expected all uses to be replaced");
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op.erase();
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continue;
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}
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// Add any the regions of this operation to the worklist.
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addToWorklist(op.getRegions());
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}
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// Replace any block arguments with constants.
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builder.setInsertionPointToStart(block);
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for (BlockArgument arg : block->getArguments())
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(void)replaceWithConstant(solver, builder, folder, arg);
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}
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}
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namespace {
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struct TestIntRangeInference
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: PassWrapper<TestIntRangeInference, OperationPass<>> {
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MLIR_DEFINE_EXPLICIT_INTERNAL_INLINE_TYPE_ID(TestIntRangeInference)
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StringRef getArgument() const final { return "test-int-range-inference"; }
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StringRef getDescription() const final {
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return "Test integer range inference analysis";
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}
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void runOnOperation() override {
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Operation *op = getOperation();
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DataFlowSolver solver;
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solver.load<DeadCodeAnalysis>();
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solver.load<IntegerRangeAnalysis>();
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if (failed(solver.initializeAndRun(op)))
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return signalPassFailure();
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rewrite(solver, op->getContext(), op->getRegions());
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}
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};
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} // end anonymous namespace
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namespace mlir {
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namespace test {
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void registerTestIntRangeInference() {
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PassRegistration<TestIntRangeInference>();
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}
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} // end namespace test
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} // end namespace mlir
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