llvm-project/mlir/lib/Conversion/VectorToLLVM/ConvertVectorToLLVMPass.cpp
Erick Ochoa Lopez 9d19250610
[mlir][vector] Add vector.to_elements unrolling (#157142)
This PR adds support for unrolling `vector.to_element`'s source operand.

It transforms

```mlir
%0:8 = vector.to_elements %v : vector<2x2x2xf32>
```

to

```mlir
%v0 = vector.extract %v[0] : vector<2x2xf32> from vector<2x2x2xf32>
%v1 = vector.extract %v[1] : vector<2x2xf32> from vector<2x2x2xf32>
%0:4 = vector.to_elements %v0 : vector<2x2xf32>
%1:4 = vector.to_elements %v1 : vector<2x2xf32>
// %0:8 = %0:4 - %1:4
```

This pattern will be applied until there are only 1-D vectors left.

---------

Signed-off-by: hanhanW <hanhan0912@gmail.com>
Co-authored-by: hanhanW <hanhan0912@gmail.com>
Co-authored-by: Jakub Kuderski <kubakuderski@gmail.com>
2025-09-11 13:56:57 -04:00

152 lines
6.2 KiB
C++

//===- VectorToLLVM.cpp - Conversion from Vector to the LLVM dialect ------===//
//
// 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/Conversion/VectorToLLVM/ConvertVectorToLLVMPass.h"
#include "mlir/Conversion/LLVMCommon/ConversionTarget.h"
#include "mlir/Conversion/LLVMCommon/TypeConverter.h"
#include "mlir/Dialect/AMX/AMXDialect.h"
#include "mlir/Dialect/AMX/Transforms.h"
#include "mlir/Dialect/Arith/IR/Arith.h"
#include "mlir/Dialect/ArmNeon/ArmNeonDialect.h"
#include "mlir/Dialect/ArmNeon/Transforms.h"
#include "mlir/Dialect/ArmSVE/IR/ArmSVEDialect.h"
#include "mlir/Dialect/ArmSVE/Transforms/Transforms.h"
#include "mlir/Dialect/LLVMIR/LLVMDialect.h"
#include "mlir/Dialect/MemRef/IR/MemRef.h"
#include "mlir/Dialect/Tensor/IR/Tensor.h"
#include "mlir/Dialect/Vector/Transforms/LoweringPatterns.h"
#include "mlir/Dialect/Vector/Transforms/VectorRewritePatterns.h"
#include "mlir/Dialect/X86Vector/Transforms.h"
#include "mlir/Dialect/X86Vector/X86VectorDialect.h"
#include "mlir/Pass/Pass.h"
#include "mlir/Transforms/GreedyPatternRewriteDriver.h"
namespace mlir {
#define GEN_PASS_DEF_CONVERTVECTORTOLLVMPASS
#include "mlir/Conversion/Passes.h.inc"
} // namespace mlir
using namespace mlir;
using namespace mlir::vector;
namespace {
struct ConvertVectorToLLVMPass
: public impl::ConvertVectorToLLVMPassBase<ConvertVectorToLLVMPass> {
using Base::Base;
// Override explicitly to allow conditional dialect dependence.
void getDependentDialects(DialectRegistry &registry) const override {
registry.insert<LLVM::LLVMDialect>();
registry.insert<arith::ArithDialect>();
registry.insert<memref::MemRefDialect>();
registry.insert<tensor::TensorDialect>();
if (armNeon)
registry.insert<arm_neon::ArmNeonDialect>();
if (armSVE)
registry.insert<arm_sve::ArmSVEDialect>();
if (amx)
registry.insert<amx::AMXDialect>();
if (x86Vector)
registry.insert<x86vector::X86VectorDialect>();
}
void runOnOperation() override;
};
} // namespace
void ConvertVectorToLLVMPass::runOnOperation() {
// Perform progressive lowering of operations on slices and all contraction
// operations. Also materializes masks, lowers vector.step, rank-reduces FMA,
// applies folding and DCE.
{
RewritePatternSet patterns(&getContext());
populateVectorToVectorCanonicalizationPatterns(patterns);
populateVectorBitCastLoweringPatterns(patterns);
populateVectorBroadcastLoweringPatterns(patterns);
populateVectorContractLoweringPatterns(patterns, vectorContractLowering);
if (vectorContractLowering == vector::VectorContractLowering::Matmul) {
// This pattern creates a dependency on the LLVM dialect, hence we don't
// include it in `populateVectorContractLoweringPatterns` that is part of
// the Vector dialect (and should not depend on LLVM).
populateVectorContractToMatrixMultiply(patterns);
}
populateVectorMaskOpLoweringPatterns(patterns);
populateVectorShapeCastLoweringPatterns(patterns);
populateVectorInterleaveLoweringPatterns(patterns);
populateVectorTransposeLoweringPatterns(patterns, vectorTransposeLowering);
if (vectorTransposeLowering == vector::VectorTransposeLowering::Flat) {
// This pattern creates a dependency on the LLVM dialect, hence we don't
// include it in `populateVectorTransposeLoweringPatterns` that is part of
// the Vector dialect (and should not depend on LLVM).
populateVectorTransposeToFlatTranspose(patterns);
}
// Vector transfer ops with rank > 1 should be lowered with VectorToSCF.
populateVectorTransferLoweringPatterns(patterns, /*maxTransferRank=*/1);
populateVectorMaskMaterializationPatterns(patterns,
force32BitVectorIndices);
populateVectorInsertExtractStridedSliceTransforms(patterns);
populateVectorStepLoweringPatterns(patterns);
populateVectorRankReducingFMAPattern(patterns);
populateVectorGatherLoweringPatterns(patterns);
populateVectorFromElementsLoweringPatterns(patterns);
populateVectorToElementsLoweringPatterns(patterns);
if (armI8MM) {
if (armNeon)
arm_neon::populateLowerContractionToNeonI8MMPatterns(patterns);
if (armSVE)
populateLowerContractionToSVEI8MMPatterns(patterns);
}
if (armBF16) {
if (armNeon)
arm_neon::populateLowerContractionToNeonBFMMLAPatterns(patterns);
if (armSVE)
populateLowerContractionToSVEBFMMLAPatterns(patterns);
}
(void)applyPatternsGreedily(getOperation(), std::move(patterns));
}
// Convert to the LLVM IR dialect.
LowerToLLVMOptions options(&getContext());
LLVMTypeConverter converter(&getContext(), options);
RewritePatternSet patterns(&getContext());
populateVectorTransferLoweringPatterns(patterns);
populateVectorToLLVMConversionPatterns(
converter, patterns, reassociateFPReductions, force32BitVectorIndices,
useVectorAlignment);
// Architecture specific augmentations.
LLVMConversionTarget target(getContext());
target.addLegalDialect<arith::ArithDialect>();
target.addLegalDialect<memref::MemRefDialect>();
target.addLegalOp<UnrealizedConversionCastOp>();
if (armNeon) {
// TODO: we may or may not want to include in-dialect lowering to
// LLVM-compatible operations here. So far, all operations in the dialect
// can be translated to LLVM IR so there is no conversion necessary.
target.addLegalDialect<arm_neon::ArmNeonDialect>();
}
if (armSVE) {
configureArmSVELegalizeForExportTarget(target);
populateArmSVELegalizeForLLVMExportPatterns(converter, patterns);
}
if (amx) {
configureAMXLegalizeForExportTarget(target);
populateAMXLegalizeForLLVMExportPatterns(converter, patterns);
}
if (x86Vector) {
configureX86VectorLegalizeForExportTarget(target);
populateX86VectorLegalizeForLLVMExportPatterns(converter, patterns);
}
if (failed(
applyPartialConversion(getOperation(), target, std::move(patterns))))
signalPassFailure();
}