llvm-project/mlir/lib/Conversion/GPUToNVVM/LowerGpuOpsToNVVMOps.cpp
Michele Scuttari 67d0d7ac0a
[MLIR] Update pass declarations to new autogenerated files
The patch introduces the required changes to update the pass declarations and definitions to use the new autogenerated files and allow dropping the old infrastructure.

Reviewed By: mehdi_amini, rriddle

Differential Review: https://reviews.llvm.org/D132838
2022-08-31 12:28:45 +02:00

299 lines
14 KiB
C++

//===- LowerGpuOpsToNVVMOps.cpp - MLIR GPU to NVVM lowering passes --------===//
//
// 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
//
//===----------------------------------------------------------------------===//
//
// This file implements a pass to generate NVVMIR operations for higher-level
// GPU operations.
//
//===----------------------------------------------------------------------===//
#include "mlir/Conversion/GPUToNVVM/GPUToNVVMPass.h"
#include "mlir/Conversion/ArithmeticToLLVM/ArithmeticToLLVM.h"
#include "mlir/Conversion/ControlFlowToLLVM/ControlFlowToLLVM.h"
#include "mlir/Conversion/FuncToLLVM/ConvertFuncToLLVM.h"
#include "mlir/Conversion/LLVMCommon/ConversionTarget.h"
#include "mlir/Conversion/LLVMCommon/LoweringOptions.h"
#include "mlir/Conversion/LLVMCommon/TypeConverter.h"
#include "mlir/Conversion/MemRefToLLVM/MemRefToLLVM.h"
#include "mlir/Dialect/Arithmetic/IR/Arithmetic.h"
#include "mlir/Dialect/ControlFlow/IR/ControlFlow.h"
#include "mlir/Dialect/Func/IR/FuncOps.h"
#include "mlir/Dialect/GPU/IR/GPUDialect.h"
#include "mlir/Dialect/GPU/Transforms/Passes.h"
#include "mlir/Dialect/LLVMIR/NVVMDialect.h"
#include "mlir/Dialect/Math/IR/Math.h"
#include "mlir/Dialect/MemRef/IR/MemRef.h"
#include "mlir/IR/BlockAndValueMapping.h"
#include "mlir/Transforms/DialectConversion.h"
#include "mlir/Transforms/GreedyPatternRewriteDriver.h"
#include "llvm/Support/FormatVariadic.h"
#include "../GPUCommon/GPUOpsLowering.h"
#include "../GPUCommon/IndexIntrinsicsOpLowering.h"
#include "../GPUCommon/OpToFuncCallLowering.h"
namespace mlir {
#define GEN_PASS_DEF_CONVERTGPUOPSTONVVMOPS
#include "mlir/Conversion/Passes.h.inc"
} // namespace mlir
using namespace mlir;
namespace {
/// Convert gpu dialect shfl mode enum to the equivalent nvvm one.
static NVVM::ShflKind convertShflKind(gpu::ShuffleMode mode) {
switch (mode) {
case gpu::ShuffleMode::XOR:
return NVVM::ShflKind::bfly;
case gpu::ShuffleMode::UP:
return NVVM::ShflKind::up;
case gpu::ShuffleMode::DOWN:
return NVVM::ShflKind::down;
case gpu::ShuffleMode::IDX:
return NVVM::ShflKind::idx;
}
llvm_unreachable("unknown shuffle mode");
}
struct GPUShuffleOpLowering : public ConvertOpToLLVMPattern<gpu::ShuffleOp> {
using ConvertOpToLLVMPattern<gpu::ShuffleOp>::ConvertOpToLLVMPattern;
/// Lowers a shuffle to the corresponding NVVM op.
///
/// Convert the `width` argument into an activeMask (a bitmask which specifies
/// which threads participate in the shuffle) and a maskAndClamp (specifying
/// the highest lane which participates in the shuffle).
///
/// %one = llvm.constant(1 : i32) : i32
/// %minus_one = llvm.constant(-1 : i32) : i32
/// %thirty_two = llvm.constant(32 : i32) : i32
/// %num_lanes = llvm.sub %thirty_two, %width : i32
/// %active_mask = llvm.lshr %minus_one, %num_lanes : i32
/// %mask_and_clamp = llvm.sub %width, %one : i32
/// %shfl = nvvm.shfl.sync.bfly %active_mask, %value, %offset,
/// %mask_and_clamp : !llvm<"{ float, i1 }">
/// %shfl_value = llvm.extractvalue %shfl[0] :
/// !llvm<"{ float, i1 }">
/// %shfl_pred = llvm.extractvalue %shfl[1] :
/// !llvm<"{ float, i1 }">
LogicalResult
matchAndRewrite(gpu::ShuffleOp op, OpAdaptor adaptor,
ConversionPatternRewriter &rewriter) const override {
Location loc = op->getLoc();
auto valueTy = adaptor.value().getType();
auto int32Type = IntegerType::get(rewriter.getContext(), 32);
auto predTy = IntegerType::get(rewriter.getContext(), 1);
auto resultTy = LLVM::LLVMStructType::getLiteral(rewriter.getContext(),
{valueTy, predTy});
Value one = rewriter.create<LLVM::ConstantOp>(loc, int32Type, 1);
Value minusOne = rewriter.create<LLVM::ConstantOp>(loc, int32Type, -1);
Value thirtyTwo = rewriter.create<LLVM::ConstantOp>(loc, int32Type, 32);
Value numLeadInactiveLane = rewriter.create<LLVM::SubOp>(
loc, int32Type, thirtyTwo, adaptor.width());
// Bit mask of active lanes: `(-1) >> (32 - activeWidth)`.
Value activeMask = rewriter.create<LLVM::LShrOp>(loc, int32Type, minusOne,
numLeadInactiveLane);
Value maskAndClamp;
if (op.mode() == gpu::ShuffleMode::UP) {
// Clamp lane: `32 - activeWidth`
maskAndClamp = numLeadInactiveLane;
} else {
// Clamp lane: `activeWidth - 1`
maskAndClamp =
rewriter.create<LLVM::SubOp>(loc, int32Type, adaptor.width(), one);
}
auto returnValueAndIsValidAttr = rewriter.getUnitAttr();
Value shfl = rewriter.create<NVVM::ShflOp>(
loc, resultTy, activeMask, adaptor.value(), adaptor.offset(),
maskAndClamp, convertShflKind(op.mode()), returnValueAndIsValidAttr);
Value shflValue = rewriter.create<LLVM::ExtractValueOp>(loc, shfl, 0);
Value isActiveSrcLane = rewriter.create<LLVM::ExtractValueOp>(loc, shfl, 1);
rewriter.replaceOp(op, {shflValue, isActiveSrcLane});
return success();
}
};
struct GPULaneIdOpToNVVM : ConvertOpToLLVMPattern<gpu::LaneIdOp> {
using ConvertOpToLLVMPattern<gpu::LaneIdOp>::ConvertOpToLLVMPattern;
LogicalResult
matchAndRewrite(gpu::LaneIdOp op, gpu::LaneIdOp::Adaptor adaptor,
ConversionPatternRewriter &rewriter) const override {
auto loc = op->getLoc();
MLIRContext *context = rewriter.getContext();
Value newOp = rewriter.create<NVVM::LaneIdOp>(loc, rewriter.getI32Type());
// Truncate or extend the result depending on the index bitwidth specified
// by the LLVMTypeConverter options.
const unsigned indexBitwidth = getTypeConverter()->getIndexTypeBitwidth();
if (indexBitwidth > 32) {
newOp = rewriter.create<LLVM::SExtOp>(
loc, IntegerType::get(context, indexBitwidth), newOp);
} else if (indexBitwidth < 32) {
newOp = rewriter.create<LLVM::TruncOp>(
loc, IntegerType::get(context, indexBitwidth), newOp);
}
rewriter.replaceOp(op, {newOp});
return success();
}
};
/// Import the GPU Ops to NVVM Patterns.
#include "GPUToNVVM.cpp.inc"
/// A pass that replaces all occurrences of GPU device operations with their
/// corresponding NVVM equivalent.
///
/// This pass only handles device code and is not meant to be run on GPU host
/// code.
struct LowerGpuOpsToNVVMOpsPass
: public impl::ConvertGpuOpsToNVVMOpsBase<LowerGpuOpsToNVVMOpsPass> {
LowerGpuOpsToNVVMOpsPass() = default;
LowerGpuOpsToNVVMOpsPass(unsigned indexBitwidth) {
this->indexBitwidth = indexBitwidth;
}
void runOnOperation() override {
gpu::GPUModuleOp m = getOperation();
// Request C wrapper emission.
for (auto func : m.getOps<func::FuncOp>()) {
func->setAttr(LLVM::LLVMDialect::getEmitCWrapperAttrName(),
UnitAttr::get(&getContext()));
}
// Customize the bitwidth used for the device side index computations.
LowerToLLVMOptions options(
m.getContext(),
DataLayout(cast<DataLayoutOpInterface>(m.getOperation())));
if (indexBitwidth != kDeriveIndexBitwidthFromDataLayout)
options.overrideIndexBitwidth(indexBitwidth);
// MemRef conversion for GPU to NVVM lowering. The GPU dialect uses memory
// space 5 for private memory attributions, but NVVM represents private
// memory allocations as local `alloca`s in the default address space. This
// converter drops the private memory space to support the use case above.
LLVMTypeConverter converter(m.getContext(), options);
converter.addConversion([&](MemRefType type) -> Optional<Type> {
if (type.getMemorySpaceAsInt() !=
gpu::GPUDialect::getPrivateAddressSpace())
return llvm::None;
return converter.convertType(MemRefType::Builder(type).setMemorySpace(
IntegerAttr::get(IntegerType::get(m.getContext(), 64), 0)));
});
// Lowering for MMAMatrixType.
converter.addConversion([&](gpu::MMAMatrixType type) -> Type {
return convertMMAToLLVMType(type);
});
RewritePatternSet patterns(m.getContext());
RewritePatternSet llvmPatterns(m.getContext());
// Apply in-dialect lowering first. In-dialect lowering will replace ops
// which need to be lowered further, which is not supported by a single
// conversion pass.
populateGpuRewritePatterns(patterns);
(void)applyPatternsAndFoldGreedily(m, std::move(patterns));
arith::populateArithmeticToLLVMConversionPatterns(converter, llvmPatterns);
cf::populateControlFlowToLLVMConversionPatterns(converter, llvmPatterns);
populateFuncToLLVMConversionPatterns(converter, llvmPatterns);
populateMemRefToLLVMConversionPatterns(converter, llvmPatterns);
populateGpuToNVVMConversionPatterns(converter, llvmPatterns);
populateGpuWMMAToNVVMConversionPatterns(converter, llvmPatterns);
LLVMConversionTarget target(getContext());
configureGpuToNVVMConversionLegality(target);
if (failed(applyPartialConversion(m, target, std::move(llvmPatterns))))
signalPassFailure();
}
};
} // namespace
void mlir::configureGpuToNVVMConversionLegality(ConversionTarget &target) {
target.addIllegalOp<func::FuncOp>();
target.addLegalDialect<::mlir::LLVM::LLVMDialect>();
target.addLegalDialect<::mlir::NVVM::NVVMDialect>();
target.addIllegalDialect<gpu::GPUDialect>();
target.addIllegalOp<LLVM::CosOp, LLVM::ExpOp, LLVM::Exp2Op, LLVM::FAbsOp,
LLVM::FCeilOp, LLVM::FFloorOp, LLVM::LogOp, LLVM::Log10Op,
LLVM::Log2Op, LLVM::PowOp, LLVM::SinOp, LLVM::SqrtOp>();
// TODO: Remove once we support replacing non-root ops.
target.addLegalOp<gpu::YieldOp, gpu::GPUModuleOp, gpu::ModuleEndOp>();
}
void mlir::populateGpuToNVVMConversionPatterns(LLVMTypeConverter &converter,
RewritePatternSet &patterns) {
populateWithGenerated(patterns);
patterns
.add<GPUIndexIntrinsicOpLowering<gpu::ThreadIdOp, NVVM::ThreadIdXOp,
NVVM::ThreadIdYOp, NVVM::ThreadIdZOp>,
GPUIndexIntrinsicOpLowering<gpu::BlockDimOp, NVVM::BlockDimXOp,
NVVM::BlockDimYOp, NVVM::BlockDimZOp>,
GPUIndexIntrinsicOpLowering<gpu::BlockIdOp, NVVM::BlockIdXOp,
NVVM::BlockIdYOp, NVVM::BlockIdZOp>,
GPUIndexIntrinsicOpLowering<gpu::GridDimOp, NVVM::GridDimXOp,
NVVM::GridDimYOp, NVVM::GridDimZOp>,
GPULaneIdOpToNVVM, GPUShuffleOpLowering, GPUReturnOpLowering>(
converter);
// Explicitly drop memory space when lowering private memory
// attributions since NVVM models it as `alloca`s in the default
// memory space and does not support `alloca`s with addrspace(5).
patterns.add<GPUFuncOpLowering>(
converter, /*allocaAddrSpace=*/0,
StringAttr::get(&converter.getContext(),
NVVM::NVVMDialect::getKernelFuncAttrName()));
patterns.add<OpToFuncCallLowering<math::AbsFOp>>(converter, "__nv_fabsf",
"__nv_fabs");
patterns.add<OpToFuncCallLowering<math::AtanOp>>(converter, "__nv_atanf",
"__nv_atan");
patterns.add<OpToFuncCallLowering<math::Atan2Op>>(converter, "__nv_atan2f",
"__nv_atan2");
patterns.add<OpToFuncCallLowering<math::CeilOp>>(converter, "__nv_ceilf",
"__nv_ceil");
patterns.add<OpToFuncCallLowering<math::CosOp>>(converter, "__nv_cosf",
"__nv_cos");
patterns.add<OpToFuncCallLowering<math::ExpOp>>(converter, "__nv_expf",
"__nv_exp");
patterns.add<OpToFuncCallLowering<math::Exp2Op>>(converter, "__nv_exp2f",
"__nv_exp2");
patterns.add<OpToFuncCallLowering<math::ExpM1Op>>(converter, "__nv_expm1f",
"__nv_expm1");
patterns.add<OpToFuncCallLowering<math::FloorOp>>(converter, "__nv_floorf",
"__nv_floor");
patterns.add<OpToFuncCallLowering<math::LogOp>>(converter, "__nv_logf",
"__nv_log");
patterns.add<OpToFuncCallLowering<math::Log1pOp>>(converter, "__nv_log1pf",
"__nv_log1p");
patterns.add<OpToFuncCallLowering<math::Log10Op>>(converter, "__nv_log10f",
"__nv_log10");
patterns.add<OpToFuncCallLowering<math::Log2Op>>(converter, "__nv_log2f",
"__nv_log2");
patterns.add<OpToFuncCallLowering<math::PowFOp>>(converter, "__nv_powf",
"__nv_pow");
patterns.add<OpToFuncCallLowering<math::RsqrtOp>>(converter, "__nv_rsqrtf",
"__nv_rsqrt");
patterns.add<OpToFuncCallLowering<math::SinOp>>(converter, "__nv_sinf",
"__nv_sin");
patterns.add<OpToFuncCallLowering<math::SqrtOp>>(converter, "__nv_sqrtf",
"__nv_sqrt");
patterns.add<OpToFuncCallLowering<math::TanhOp>>(converter, "__nv_tanhf",
"__nv_tanh");
}
std::unique_ptr<OperationPass<gpu::GPUModuleOp>>
mlir::createLowerGpuOpsToNVVMOpsPass(unsigned indexBitwidth) {
return std::make_unique<LowerGpuOpsToNVVMOpsPass>(indexBitwidth);
}