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rust / rust-lang / llvm-project / refs/heads/rustc/11.0-2020-10-12 / . / mlir / lib / Conversion / StandardToLLVM / StandardToLLVM.cpp
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//===- StandardToLLVM.cpp - Standard to LLVM dialect conversion -----------===//
//
// 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 convert MLIR standard and builtin dialects
// into the LLVM IR dialect.
//
//===----------------------------------------------------------------------===//
#include "../PassDetail.h"
#include "mlir/Conversion/StandardToLLVM/ConvertStandardToLLVM.h"
#include "mlir/Conversion/StandardToLLVM/ConvertStandardToLLVMPass.h"
#include "mlir/Dialect/LLVMIR/LLVMDialect.h"
#include "mlir/Dialect/StandardOps/IR/Ops.h"
#include "mlir/IR/Attributes.h"
#include "mlir/IR/BlockAndValueMapping.h"
#include "mlir/IR/Builders.h"
#include "mlir/IR/MLIRContext.h"
#include "mlir/IR/Module.h"
#include "mlir/IR/PatternMatch.h"
#include "mlir/IR/TypeUtilities.h"
#include "mlir/Support/LogicalResult.h"
#include "mlir/Support/MathExtras.h"
#include "mlir/Transforms/DialectConversion.h"
#include "mlir/Transforms/Passes.h"
#include "mlir/Transforms/Utils.h"
#include "llvm/ADT/TypeSwitch.h"
#include "llvm/IR/DerivedTypes.h"
#include "llvm/IR/IRBuilder.h"
#include "llvm/IR/Type.h"
#include "llvm/Support/CommandLine.h"
#include "llvm/Support/FormatVariadic.h"
#include <functional>
using namespace mlir;
#define PASS_NAME "convert-std-to-llvm"
// Extract an LLVM IR type from the LLVM IR dialect type.
static LLVM::LLVMType unwrap(Type type) {
if (!type)
return nullptr;
auto *mlirContext = type.getContext();
auto wrappedLLVMType = type.dyn_cast<LLVM::LLVMType>();
if (!wrappedLLVMType)
emitError(UnknownLoc::get(mlirContext),
"conversion resulted in a non-LLVM type");
return wrappedLLVMType;
}
/// Callback to convert function argument types. It converts a MemRef function
/// argument to a list of non-aggregate types containing descriptor
/// information, and an UnrankedmemRef function argument to a list containing
/// the rank and a pointer to a descriptor struct.
LogicalResult mlir::structFuncArgTypeConverter(LLVMTypeConverter &converter,
Type type,
SmallVectorImpl<Type> &result) {
if (auto memref = type.dyn_cast<MemRefType>()) {
auto converted = converter.convertMemRefSignature(memref);
if (converted.empty())
return failure();
result.append(converted.begin(), converted.end());
return success();
}
if (type.isa<UnrankedMemRefType>()) {
auto converted = converter.convertUnrankedMemRefSignature();
if (converted.empty())
return failure();
result.append(converted.begin(), converted.end());
return success();
}
auto converted = converter.convertType(type);
if (!converted)
return failure();
result.push_back(converted);
return success();
}
/// Convert a MemRef type to a bare pointer to the MemRef element type.
static Type convertMemRefTypeToBarePtr(LLVMTypeConverter &converter,
MemRefType type) {
int64_t offset;
SmallVector<int64_t, 4> strides;
if (failed(getStridesAndOffset(type, strides, offset)))
return {};
LLVM::LLVMType elementType =
unwrap(converter.convertType(type.getElementType()));
if (!elementType)
return {};
return elementType.getPointerTo(type.getMemorySpace());
}
/// Callback to convert function argument types. It converts MemRef function
/// arguments to bare pointers to the MemRef element type.
LogicalResult mlir::barePtrFuncArgTypeConverter(LLVMTypeConverter &converter,
Type type,
SmallVectorImpl<Type> &result) {
// TODO: Add support for unranked memref.
if (auto memrefTy = type.dyn_cast<MemRefType>()) {
auto llvmTy = convertMemRefTypeToBarePtr(converter, memrefTy);
if (!llvmTy)
return failure();
result.push_back(llvmTy);
return success();
}
auto llvmTy = converter.convertType(type);
if (!llvmTy)
return failure();
result.push_back(llvmTy);
return success();
}
/// Create an LLVMTypeConverter using default LowerToLLVMOptions.
LLVMTypeConverter::LLVMTypeConverter(MLIRContext *ctx)
: LLVMTypeConverter(ctx, LowerToLLVMOptions::getDefaultOptions()) {}
/// Create an LLVMTypeConverter using custom LowerToLLVMOptions.
LLVMTypeConverter::LLVMTypeConverter(MLIRContext *ctx,
const LowerToLLVMOptions &options)
: llvmDialect(ctx->getRegisteredDialect<LLVM::LLVMDialect>()),
options(options) {
assert(llvmDialect && "LLVM IR dialect is not registered");
module = &llvmDialect->getLLVMModule();
if (options.indexBitwidth == kDeriveIndexBitwidthFromDataLayout)
this->options.indexBitwidth =
module->getDataLayout().getPointerSizeInBits();
// Register conversions for the standard types.
addConversion([&](ComplexType type) { return convertComplexType(type); });
addConversion([&](FloatType type) { return convertFloatType(type); });
addConversion([&](FunctionType type) { return convertFunctionType(type); });
addConversion([&](IndexType type) { return convertIndexType(type); });
addConversion([&](IntegerType type) { return convertIntegerType(type); });
addConversion([&](MemRefType type) { return convertMemRefType(type); });
addConversion(
[&](UnrankedMemRefType type) { return convertUnrankedMemRefType(type); });
addConversion([&](VectorType type) { return convertVectorType(type); });
// LLVMType is legal, so add a pass-through conversion.
addConversion([](LLVM::LLVMType type) { return type; });
// Materialization for memrefs creates descriptor structs from individual
// values constituting them, when descriptors are used, i.e. more than one
// value represents a memref.
addMaterialization([&](PatternRewriter &rewriter,
UnrankedMemRefType resultType, ValueRange inputs,
Location loc) -> Optional<Value> {
if (inputs.size() == 1)
return llvm::None;
return UnrankedMemRefDescriptor::pack(rewriter, loc, *this, resultType,
inputs);
});
addMaterialization([&](PatternRewriter &rewriter, MemRefType resultType,
ValueRange inputs, Location loc) -> Optional<Value> {
if (inputs.size() == 1)
return llvm::None;
return MemRefDescriptor::pack(rewriter, loc, *this, resultType, inputs);
});
}
/// Returns the MLIR context.
MLIRContext &LLVMTypeConverter::getContext() {
return *getDialect()->getContext();
}
/// Get the LLVM context.
llvm::LLVMContext &LLVMTypeConverter::getLLVMContext() {
return module->getContext();
}
LLVM::LLVMType LLVMTypeConverter::getIndexType() {
return LLVM::LLVMType::getIntNTy(llvmDialect, getIndexTypeBitwidth());
}
unsigned LLVMTypeConverter::getPointerBitwidth(unsigned addressSpace) {
return module->getDataLayout().getPointerSizeInBits(addressSpace);
}
Type LLVMTypeConverter::convertIndexType(IndexType type) {
return getIndexType();
}
Type LLVMTypeConverter::convertIntegerType(IntegerType type) {
return LLVM::LLVMType::getIntNTy(llvmDialect, type.getWidth());
}
Type LLVMTypeConverter::convertFloatType(FloatType type) {
switch (type.getKind()) {
case mlir::StandardTypes::F32:
return LLVM::LLVMType::getFloatTy(llvmDialect);
case mlir::StandardTypes::F64:
return LLVM::LLVMType::getDoubleTy(llvmDialect);
case mlir::StandardTypes::F16:
return LLVM::LLVMType::getHalfTy(llvmDialect);
case mlir::StandardTypes::BF16: {
return LLVM::LLVMType::getBFloatTy(llvmDialect);
}
default:
llvm_unreachable("non-float type in convertFloatType");
}
}
// Convert a `ComplexType` to an LLVM type. The result is a complex number
// struct with entries for the
// 1. real part and for the
// 2. imaginary part.
static constexpr unsigned kRealPosInComplexNumberStruct = 0;
static constexpr unsigned kImaginaryPosInComplexNumberStruct = 1;
Type LLVMTypeConverter::convertComplexType(ComplexType type) {
auto elementType = convertType(type.getElementType()).cast<LLVM::LLVMType>();
return LLVM::LLVMType::getStructTy(llvmDialect, {elementType, elementType});
}
// Except for signatures, MLIR function types are converted into LLVM
// pointer-to-function types.
Type LLVMTypeConverter::convertFunctionType(FunctionType type) {
SignatureConversion conversion(type.getNumInputs());
LLVM::LLVMType converted =
convertFunctionSignature(type, /*isVariadic=*/false, conversion);
return converted.getPointerTo();
}
/// In signatures, MemRef descriptors are expanded into lists of non-aggregate
/// values.
SmallVector<Type, 5>
LLVMTypeConverter::convertMemRefSignature(MemRefType type) {
SmallVector<Type, 5> results;
assert(isStrided(type) &&
"Non-strided layout maps must have been normalized away");
LLVM::LLVMType elementType = unwrap(convertType(type.getElementType()));
if (!elementType)
return {};
auto indexTy = getIndexType();
results.insert(results.begin(), 2,
elementType.getPointerTo(type.getMemorySpace()));
results.push_back(indexTy);
auto rank = type.getRank();
results.insert(results.end(), 2 * rank, indexTy);
return results;
}
/// In signatures, unranked MemRef descriptors are expanded into a pair "rank,
/// pointer to descriptor".
SmallVector<Type, 2> LLVMTypeConverter::convertUnrankedMemRefSignature() {
return {getIndexType(), LLVM::LLVMType::getInt8PtrTy(llvmDialect)};
}
// Function types are converted to LLVM Function types by recursively converting
// argument and result types. If MLIR Function has zero results, the LLVM
// Function has one VoidType result. If MLIR Function has more than one result,
// they are into an LLVM StructType in their order of appearance.
LLVM::LLVMType LLVMTypeConverter::convertFunctionSignature(
FunctionType type, bool isVariadic,
LLVMTypeConverter::SignatureConversion &result) {
// Select the argument converter depending on the calling convetion.
auto funcArgConverter = options.useBarePtrCallConv
? barePtrFuncArgTypeConverter
: structFuncArgTypeConverter;
// Convert argument types one by one and check for errors.
for (auto &en : llvm::enumerate(type.getInputs())) {
Type type = en.value();
SmallVector<Type, 8> converted;
if (failed(funcArgConverter(*this, type, converted)))
return {};
result.addInputs(en.index(), converted);
}
SmallVector<LLVM::LLVMType, 8> argTypes;
argTypes.reserve(llvm::size(result.getConvertedTypes()));
for (Type type : result.getConvertedTypes())
argTypes.push_back(unwrap(type));
// If function does not return anything, create the void result type,
// if it returns on element, convert it, otherwise pack the result types into
// a struct.
LLVM::LLVMType resultType =
type.getNumResults() == 0
? LLVM::LLVMType::getVoidTy(llvmDialect)
: unwrap(packFunctionResults(type.getResults()));
if (!resultType)
return {};
return LLVM::LLVMType::getFunctionTy(resultType, argTypes, isVariadic);
}
/// Converts the function type to a C-compatible format, in particular using
/// pointers to memref descriptors for arguments.
LLVM::LLVMType
LLVMTypeConverter::convertFunctionTypeCWrapper(FunctionType type) {
SmallVector<LLVM::LLVMType, 4> inputs;
for (Type t : type.getInputs()) {
auto converted = convertType(t).dyn_cast_or_null<LLVM::LLVMType>();
if (!converted)
return {};
if (t.isa<MemRefType, UnrankedMemRefType>())
converted = converted.getPointerTo();
inputs.push_back(converted);
}
LLVM::LLVMType resultType =
type.getNumResults() == 0
? LLVM::LLVMType::getVoidTy(llvmDialect)
: unwrap(packFunctionResults(type.getResults()));
if (!resultType)
return {};
return LLVM::LLVMType::getFunctionTy(resultType, inputs, false);
}
// Convert a MemRef to an LLVM type. The result is a MemRef descriptor which
// contains:
// 1. the pointer to the data buffer, followed by
// 2. a lowered `index`-type integer containing the distance between the
// beginning of the buffer and the first element to be accessed through the
// view, followed by
// 3. an array containing as many `index`-type integers as the rank of the
// MemRef: the array represents the size, in number of elements, of the memref
// along the given dimension. For constant MemRef dimensions, the
// corresponding size entry is a constant whose runtime value must match the
// static value, followed by
// 4. a second array containing as many `index`-type integers as the rank of
// the MemRef: the second array represents the "stride" (in tensor abstraction
// sense), i.e. the number of consecutive elements of the underlying buffer.
// TODO: add assertions for the static cases.
//
// template <typename Elem, size_t Rank>
// struct {
// Elem *allocatedPtr;
// Elem *alignedPtr;
// int64_t offset;
// int64_t sizes[Rank]; // omitted when rank == 0
// int64_t strides[Rank]; // omitted when rank == 0
// };
static constexpr unsigned kAllocatedPtrPosInMemRefDescriptor = 0;
static constexpr unsigned kAlignedPtrPosInMemRefDescriptor = 1;
static constexpr unsigned kOffsetPosInMemRefDescriptor = 2;
static constexpr unsigned kSizePosInMemRefDescriptor = 3;
static constexpr unsigned kStridePosInMemRefDescriptor = 4;
Type LLVMTypeConverter::convertMemRefType(MemRefType type) {
int64_t offset;
SmallVector<int64_t, 4> strides;
bool strideSuccess = succeeded(getStridesAndOffset(type, strides, offset));
assert(strideSuccess &&
"Non-strided layout maps must have been normalized away");
(void)strideSuccess;
LLVM::LLVMType elementType = unwrap(convertType(type.getElementType()));
if (!elementType)
return {};
auto ptrTy = elementType.getPointerTo(type.getMemorySpace());
auto indexTy = getIndexType();
auto rank = type.getRank();
if (rank > 0) {
auto arrayTy = LLVM::LLVMType::getArrayTy(indexTy, type.getRank());
return LLVM::LLVMType::getStructTy(ptrTy, ptrTy, indexTy, arrayTy, arrayTy);
}
return LLVM::LLVMType::getStructTy(ptrTy, ptrTy, indexTy);
}
// Converts UnrankedMemRefType to LLVMType. The result is a descriptor which
// contains:
// 1. int64_t rank, the dynamic rank of this MemRef
// 2. void* ptr, pointer to the static ranked MemRef descriptor. This will be
// stack allocated (alloca) copy of a MemRef descriptor that got casted to
// be unranked.
static constexpr unsigned kRankInUnrankedMemRefDescriptor = 0;
static constexpr unsigned kPtrInUnrankedMemRefDescriptor = 1;
Type LLVMTypeConverter::convertUnrankedMemRefType(UnrankedMemRefType type) {
auto rankTy = LLVM::LLVMType::getInt64Ty(llvmDialect);
auto ptrTy = LLVM::LLVMType::getInt8PtrTy(llvmDialect);
return LLVM::LLVMType::getStructTy(rankTy, ptrTy);
}
// Convert an n-D vector type to an LLVM vector type via (n-1)-D array type when
// n > 1.
// For example, `vector<4 x f32>` converts to `!llvm.type<"<4 x float>">` and
// `vector<4 x 8 x 16 f32>` converts to `!llvm<"[4 x [8 x <16 x float>]]">`.
Type LLVMTypeConverter::convertVectorType(VectorType type) {
auto elementType = unwrap(convertType(type.getElementType()));
if (!elementType)
return {};
auto vectorType =
LLVM::LLVMType::getVectorTy(elementType, type.getShape().back());
auto shape = type.getShape();
for (int i = shape.size() - 2; i >= 0; --i)
vectorType = LLVM::LLVMType::getArrayTy(vectorType, shape[i]);
return vectorType;
}
ConvertToLLVMPattern::ConvertToLLVMPattern(StringRef rootOpName,
MLIRContext *context,
LLVMTypeConverter &typeConverter,
const LowerToLLVMOptions &options,
PatternBenefit benefit)
: ConversionPattern(rootOpName, benefit, typeConverter, context),
typeConverter(typeConverter), options(options) {}
/*============================================================================*/
/* StructBuilder implementation */
/*============================================================================*/
StructBuilder::StructBuilder(Value v) : value(v) {
assert(value != nullptr && "value cannot be null");
structType = value.getType().dyn_cast<LLVM::LLVMType>();
assert(structType && "expected llvm type");
}
Value StructBuilder::extractPtr(OpBuilder &builder, Location loc,
unsigned pos) {
Type type = structType.cast<LLVM::LLVMType>().getStructElementType(pos);
return builder.create<LLVM::ExtractValueOp>(loc, type, value,
builder.getI64ArrayAttr(pos));
}
void StructBuilder::setPtr(OpBuilder &builder, Location loc, unsigned pos,
Value ptr) {
value = builder.create<LLVM::InsertValueOp>(loc, structType, value, ptr,
builder.getI64ArrayAttr(pos));
}
/*============================================================================*/
/* ComplexStructBuilder implementation */
/*============================================================================*/
ComplexStructBuilder ComplexStructBuilder::undef(OpBuilder &builder,
Location loc, Type type) {
Value val = builder.create<LLVM::UndefOp>(loc, type.cast<LLVM::LLVMType>());
return ComplexStructBuilder(val);
}
void ComplexStructBuilder::setReal(OpBuilder &builder, Location loc,
Value real) {
setPtr(builder, loc, kRealPosInComplexNumberStruct, real);
}
Value ComplexStructBuilder::real(OpBuilder &builder, Location loc) {
return extractPtr(builder, loc, kRealPosInComplexNumberStruct);
}
void ComplexStructBuilder::setImaginary(OpBuilder &builder, Location loc,
Value imaginary) {
setPtr(builder, loc, kImaginaryPosInComplexNumberStruct, imaginary);
}
Value ComplexStructBuilder::imaginary(OpBuilder &builder, Location loc) {
return extractPtr(builder, loc, kImaginaryPosInComplexNumberStruct);
}
/*============================================================================*/
/* MemRefDescriptor implementation */
/*============================================================================*/
/// Construct a helper for the given descriptor value.
MemRefDescriptor::MemRefDescriptor(Value descriptor)
: StructBuilder(descriptor) {
assert(value != nullptr && "value cannot be null");
indexType = value.getType().cast<LLVM::LLVMType>().getStructElementType(
kOffsetPosInMemRefDescriptor);
}
/// Builds IR creating an `undef` value of the descriptor type.
MemRefDescriptor MemRefDescriptor::undef(OpBuilder &builder, Location loc,
Type descriptorType) {
Value descriptor =
builder.create<LLVM::UndefOp>(loc, descriptorType.cast<LLVM::LLVMType>());
return MemRefDescriptor(descriptor);
}
/// Builds IR creating a MemRef descriptor that represents `type` and
/// populates it with static shape and stride information extracted from the
/// type.
MemRefDescriptor
MemRefDescriptor::fromStaticShape(OpBuilder &builder, Location loc,
LLVMTypeConverter &typeConverter,
MemRefType type, Value memory) {
assert(type.hasStaticShape() && "unexpected dynamic shape");
// Extract all strides and offsets and verify they are static.
int64_t offset;
SmallVector<int64_t, 4> strides;
auto result = getStridesAndOffset(type, strides, offset);
(void)result;
assert(succeeded(result) && "unexpected failure in stride computation");
assert(offset != MemRefType::getDynamicStrideOrOffset() &&
"expected static offset");
assert(!llvm::is_contained(strides, MemRefType::getDynamicStrideOrOffset()) &&
"expected static strides");
auto convertedType = typeConverter.convertType(type);
assert(convertedType && "unexpected failure in memref type conversion");
auto descr = MemRefDescriptor::undef(builder, loc, convertedType);
descr.setAllocatedPtr(builder, loc, memory);
descr.setAlignedPtr(builder, loc, memory);
descr.setConstantOffset(builder, loc, offset);
// Fill in sizes and strides
for (unsigned i = 0, e = type.getRank(); i != e; ++i) {
descr.setConstantSize(builder, loc, i, type.getDimSize(i));
descr.setConstantStride(builder, loc, i, strides[i]);
}
return descr;
}
/// Builds IR extracting the allocated pointer from the descriptor.
Value MemRefDescriptor::allocatedPtr(OpBuilder &builder, Location loc) {
return extractPtr(builder, loc, kAllocatedPtrPosInMemRefDescriptor);
}
/// Builds IR inserting the allocated pointer into the descriptor.
void MemRefDescriptor::setAllocatedPtr(OpBuilder &builder, Location loc,
Value ptr) {
setPtr(builder, loc, kAllocatedPtrPosInMemRefDescriptor, ptr);
}
/// Builds IR extracting the aligned pointer from the descriptor.
Value MemRefDescriptor::alignedPtr(OpBuilder &builder, Location loc) {
return extractPtr(builder, loc, kAlignedPtrPosInMemRefDescriptor);
}
/// Builds IR inserting the aligned pointer into the descriptor.
void MemRefDescriptor::setAlignedPtr(OpBuilder &builder, Location loc,
Value ptr) {
setPtr(builder, loc, kAlignedPtrPosInMemRefDescriptor, ptr);
}
// Creates a constant Op producing a value of `resultType` from an index-typed
// integer attribute.
static Value createIndexAttrConstant(OpBuilder &builder, Location loc,
Type resultType, int64_t value) {
return builder.create<LLVM::ConstantOp>(
loc, resultType, builder.getIntegerAttr(builder.getIndexType(), value));
}
/// Builds IR extracting the offset from the descriptor.
Value MemRefDescriptor::offset(OpBuilder &builder, Location loc) {
return builder.create<LLVM::ExtractValueOp>(
loc, indexType, value,
builder.getI64ArrayAttr(kOffsetPosInMemRefDescriptor));
}
/// Builds IR inserting the offset into the descriptor.
void MemRefDescriptor::setOffset(OpBuilder &builder, Location loc,
Value offset) {
value = builder.create<LLVM::InsertValueOp>(
loc, structType, value, offset,
builder.getI64ArrayAttr(kOffsetPosInMemRefDescriptor));
}
/// Builds IR inserting the offset into the descriptor.
void MemRefDescriptor::setConstantOffset(OpBuilder &builder, Location loc,
uint64_t offset) {
setOffset(builder, loc,
createIndexAttrConstant(builder, loc, indexType, offset));
}
/// Builds IR extracting the pos-th size from the descriptor.
Value MemRefDescriptor::size(OpBuilder &builder, Location loc, unsigned pos) {
return builder.create<LLVM::ExtractValueOp>(
loc, indexType, value,
builder.getI64ArrayAttr({kSizePosInMemRefDescriptor, pos}));
}
Value MemRefDescriptor::size(OpBuilder &builder, Location loc, Value pos,
int64_t rank) {
auto indexTy = indexType.cast<LLVM::LLVMType>();
auto indexPtrTy = indexTy.getPointerTo();
auto arrayTy = LLVM::LLVMType::getArrayTy(indexTy, rank);
auto arrayPtrTy = arrayTy.getPointerTo();
// Copy size values to stack-allocated memory.
auto zero = createIndexAttrConstant(builder, loc, indexType, 0);
auto one = createIndexAttrConstant(builder, loc, indexType, 1);
auto sizes = builder.create<LLVM::ExtractValueOp>(
loc, arrayTy, value,
builder.getI64ArrayAttr({kSizePosInMemRefDescriptor}));
auto sizesPtr =
builder.create<LLVM::AllocaOp>(loc, arrayPtrTy, one, /*alignment=*/0);
builder.create<LLVM::StoreOp>(loc, sizes, sizesPtr);
// Load an return size value of interest.
auto resultPtr = builder.create<LLVM::GEPOp>(loc, indexPtrTy, sizesPtr,
ValueRange({zero, pos}));
return builder.create<LLVM::LoadOp>(loc, resultPtr);
}
/// Builds IR inserting the pos-th size into the descriptor
void MemRefDescriptor::setSize(OpBuilder &builder, Location loc, unsigned pos,
Value size) {
value = builder.create<LLVM::InsertValueOp>(
loc, structType, value, size,
builder.getI64ArrayAttr({kSizePosInMemRefDescriptor, pos}));
}
void MemRefDescriptor::setConstantSize(OpBuilder &builder, Location loc,
unsigned pos, uint64_t size) {
setSize(builder, loc, pos,
createIndexAttrConstant(builder, loc, indexType, size));
}
/// Builds IR extracting the pos-th stride from the descriptor.
Value MemRefDescriptor::stride(OpBuilder &builder, Location loc, unsigned pos) {
return builder.create<LLVM::ExtractValueOp>(
loc, indexType, value,
builder.getI64ArrayAttr({kStridePosInMemRefDescriptor, pos}));
}
/// Builds IR inserting the pos-th stride into the descriptor
void MemRefDescriptor::setStride(OpBuilder &builder, Location loc, unsigned pos,
Value stride) {
value = builder.create<LLVM::InsertValueOp>(
loc, structType, value, stride,
builder.getI64ArrayAttr({kStridePosInMemRefDescriptor, pos}));
}
void MemRefDescriptor::setConstantStride(OpBuilder &builder, Location loc,
unsigned pos, uint64_t stride) {
setStride(builder, loc, pos,
createIndexAttrConstant(builder, loc, indexType, stride));
}
LLVM::LLVMType MemRefDescriptor::getElementType() {
return value.getType().cast<LLVM::LLVMType>().getStructElementType(
kAlignedPtrPosInMemRefDescriptor);
}
/// Creates a MemRef descriptor structure from a list of individual values
/// composing that descriptor, in the following order:
/// - allocated pointer;
/// - aligned pointer;
/// - offset;
/// - <rank> sizes;
/// - <rank> shapes;
/// where <rank> is the MemRef rank as provided in `type`.
Value MemRefDescriptor::pack(OpBuilder &builder, Location loc,
LLVMTypeConverter &converter, MemRefType type,
ValueRange values) {
Type llvmType = converter.convertType(type);
auto d = MemRefDescriptor::undef(builder, loc, llvmType);
d.setAllocatedPtr(builder, loc, values[kAllocatedPtrPosInMemRefDescriptor]);
d.setAlignedPtr(builder, loc, values[kAlignedPtrPosInMemRefDescriptor]);
d.setOffset(builder, loc, values[kOffsetPosInMemRefDescriptor]);
int64_t rank = type.getRank();
for (unsigned i = 0; i < rank; ++i) {
d.setSize(builder, loc, i, values[kSizePosInMemRefDescriptor + i]);
d.setStride(builder, loc, i, values[kSizePosInMemRefDescriptor + rank + i]);
}
return d;
}
/// Builds IR extracting individual elements of a MemRef descriptor structure
/// and returning them as `results` list.
void MemRefDescriptor::unpack(OpBuilder &builder, Location loc, Value packed,
MemRefType type,
SmallVectorImpl<Value> &results) {
int64_t rank = type.getRank();
results.reserve(results.size() + getNumUnpackedValues(type));
MemRefDescriptor d(packed);
results.push_back(d.allocatedPtr(builder, loc));
results.push_back(d.alignedPtr(builder, loc));
results.push_back(d.offset(builder, loc));
for (int64_t i = 0; i < rank; ++i)
results.push_back(d.size(builder, loc, i));
for (int64_t i = 0; i < rank; ++i)
results.push_back(d.stride(builder, loc, i));
}
/// Returns the number of non-aggregate values that would be produced by
/// `unpack`.
unsigned MemRefDescriptor::getNumUnpackedValues(MemRefType type) {
// Two pointers, offset, <rank> sizes, <rank> shapes.
return 3 + 2 * type.getRank();
}
/*============================================================================*/
/* MemRefDescriptorView implementation. */
/*============================================================================*/
MemRefDescriptorView::MemRefDescriptorView(ValueRange range)
: rank((range.size() - kSizePosInMemRefDescriptor) / 2), elements(range) {}
Value MemRefDescriptorView::allocatedPtr() {
return elements[kAllocatedPtrPosInMemRefDescriptor];
}
Value MemRefDescriptorView::alignedPtr() {
return elements[kAlignedPtrPosInMemRefDescriptor];
}
Value MemRefDescriptorView::offset() {
return elements[kOffsetPosInMemRefDescriptor];
}
Value MemRefDescriptorView::size(unsigned pos) {
return elements[kSizePosInMemRefDescriptor + pos];
}
Value MemRefDescriptorView::stride(unsigned pos) {
return elements[kSizePosInMemRefDescriptor + rank + pos];
}
/*============================================================================*/
/* UnrankedMemRefDescriptor implementation */
/*============================================================================*/
/// Construct a helper for the given descriptor value.
UnrankedMemRefDescriptor::UnrankedMemRefDescriptor(Value descriptor)
: StructBuilder(descriptor) {}
/// Builds IR creating an `undef` value of the descriptor type.
UnrankedMemRefDescriptor UnrankedMemRefDescriptor::undef(OpBuilder &builder,
Location loc,
Type descriptorType) {
Value descriptor =
builder.create<LLVM::UndefOp>(loc, descriptorType.cast<LLVM::LLVMType>());
return UnrankedMemRefDescriptor(descriptor);
}
Value UnrankedMemRefDescriptor::rank(OpBuilder &builder, Location loc) {
return extractPtr(builder, loc, kRankInUnrankedMemRefDescriptor);
}
void UnrankedMemRefDescriptor::setRank(OpBuilder &builder, Location loc,
Value v) {
setPtr(builder, loc, kRankInUnrankedMemRefDescriptor, v);
}
Value UnrankedMemRefDescriptor::memRefDescPtr(OpBuilder &builder,
Location loc) {
return extractPtr(builder, loc, kPtrInUnrankedMemRefDescriptor);
}
void UnrankedMemRefDescriptor::setMemRefDescPtr(OpBuilder &builder,
Location loc, Value v) {
setPtr(builder, loc, kPtrInUnrankedMemRefDescriptor, v);
}
/// Builds IR populating an unranked MemRef descriptor structure from a list
/// of individual constituent values in the following order:
/// - rank of the memref;
/// - pointer to the memref descriptor.
Value UnrankedMemRefDescriptor::pack(OpBuilder &builder, Location loc,
LLVMTypeConverter &converter,
UnrankedMemRefType type,
ValueRange values) {
Type llvmType = converter.convertType(type);
auto d = UnrankedMemRefDescriptor::undef(builder, loc, llvmType);
d.setRank(builder, loc, values[kRankInUnrankedMemRefDescriptor]);
d.setMemRefDescPtr(builder, loc, values[kPtrInUnrankedMemRefDescriptor]);
return d;
}
/// Builds IR extracting individual elements that compose an unranked memref
/// descriptor and returns them as `results` list.
void UnrankedMemRefDescriptor::unpack(OpBuilder &builder, Location loc,
Value packed,
SmallVectorImpl<Value> &results) {
UnrankedMemRefDescriptor d(packed);
results.reserve(results.size() + 2);
results.push_back(d.rank(builder, loc));
results.push_back(d.memRefDescPtr(builder, loc));
}
void UnrankedMemRefDescriptor::computeSizes(
OpBuilder &builder, Location loc, LLVMTypeConverter &typeConverter,
ArrayRef<UnrankedMemRefDescriptor> values, SmallVectorImpl<Value> &sizes) {
if (values.empty())
return;
// Cache the index type.
LLVM::LLVMType indexType = typeConverter.getIndexType();
// Initialize shared constants.
Value one = createIndexAttrConstant(builder, loc, indexType, 1);
Value two = createIndexAttrConstant(builder, loc, indexType, 2);
Value pointerSize = createIndexAttrConstant(
builder, loc, indexType, ceilDiv(typeConverter.getPointerBitwidth(), 8));
Value indexSize =
createIndexAttrConstant(builder, loc, indexType,
ceilDiv(typeConverter.getIndexTypeBitwidth(), 8));
sizes.reserve(sizes.size() + values.size());
for (UnrankedMemRefDescriptor desc : values) {
// Emit IR computing the memory necessary to store the descriptor. This
// assumes the descriptor to be
// { type*, type*, index, index[rank], index[rank] }
// and densely packed, so the total size is
// 2 * sizeof(pointer) + (1 + 2 * rank) * sizeof(index).
// TODO: consider including the actual size (including eventual padding due
// to data layout) into the unranked descriptor.
Value doublePointerSize =
builder.create<LLVM::MulOp>(loc, indexType, two, pointerSize);
// (1 + 2 * rank) * sizeof(index)
Value rank = desc.rank(builder, loc);
Value doubleRank = builder.create<LLVM::MulOp>(loc, indexType, two, rank);
Value doubleRankIncremented =
builder.create<LLVM::AddOp>(loc, indexType, doubleRank, one);
Value rankIndexSize = builder.create<LLVM::MulOp>(
loc, indexType, doubleRankIncremented, indexSize);
// Total allocation size.
Value allocationSize = builder.create<LLVM::AddOp>(
loc, indexType, doublePointerSize, rankIndexSize);
sizes.push_back(allocationSize);
}
}
LLVM::LLVMDialect &ConvertToLLVMPattern::getDialect() const {
return *typeConverter.getDialect();
}
llvm::LLVMContext &ConvertToLLVMPattern::getContext() const {
return typeConverter.getLLVMContext();
}
llvm::Module &ConvertToLLVMPattern::getModule() const {
return getDialect().getLLVMModule();
}
LLVM::LLVMType ConvertToLLVMPattern::getIndexType() const {
return typeConverter.getIndexType();
}
LLVM::LLVMType ConvertToLLVMPattern::getVoidType() const {
return LLVM::LLVMType::getVoidTy(&getDialect());
}
LLVM::LLVMType ConvertToLLVMPattern::getVoidPtrType() const {
return LLVM::LLVMType::getInt8PtrTy(&getDialect());
}
Value ConvertToLLVMPattern::createIndexConstant(
ConversionPatternRewriter &builder, Location loc, uint64_t value) const {
return createIndexAttrConstant(builder, loc, getIndexType(), value);
}
Value ConvertToLLVMPattern::linearizeSubscripts(
ConversionPatternRewriter &builder, Location loc, ArrayRef<Value> indices,
ArrayRef<Value> allocSizes) const {
assert(indices.size() == allocSizes.size() &&
"mismatching number of indices and allocation sizes");
assert(!indices.empty() && "cannot linearize a 0-dimensional access");
Value linearized = indices.front();
for (int i = 1, nSizes = allocSizes.size(); i < nSizes; ++i) {
linearized = builder.create<LLVM::MulOp>(
loc, this->getIndexType(), ArrayRef<Value>{linearized, allocSizes[i]});
linearized = builder.create<LLVM::AddOp>(
loc, this->getIndexType(), ArrayRef<Value>{linearized, indices[i]});
}
return linearized;
}
Value ConvertToLLVMPattern::getStridedElementPtr(
Location loc, Type elementTypePtr, Value descriptor, ValueRange indices,
ArrayRef<int64_t> strides, int64_t offset,
ConversionPatternRewriter &rewriter) const {
MemRefDescriptor memRefDescriptor(descriptor);
Value base = memRefDescriptor.alignedPtr(rewriter, loc);
Value offsetValue = offset == MemRefType::getDynamicStrideOrOffset()
? memRefDescriptor.offset(rewriter, loc)
: this->createIndexConstant(rewriter, loc, offset);
for (int i = 0, e = indices.size(); i < e; ++i) {
Value stride = strides[i] == MemRefType::getDynamicStrideOrOffset()
? memRefDescriptor.stride(rewriter, loc, i)
: this->createIndexConstant(rewriter, loc, strides[i]);
Value additionalOffset =
rewriter.create<LLVM::MulOp>(loc, indices[i], stride);
offsetValue =
rewriter.create<LLVM::AddOp>(loc, offsetValue, additionalOffset);
}
return rewriter.create<LLVM::GEPOp>(loc, elementTypePtr, base, offsetValue);
}
Value ConvertToLLVMPattern::getDataPtr(Location loc, MemRefType type,
Value memRefDesc, ValueRange indices,
ConversionPatternRewriter &rewriter,
llvm::Module &module) const {
LLVM::LLVMType ptrType = MemRefDescriptor(memRefDesc).getElementType();
int64_t offset;
SmallVector<int64_t, 4> strides;
auto successStrides = getStridesAndOffset(type, strides, offset);
assert(succeeded(successStrides) && "unexpected non-strided memref");
(void)successStrides;
return getStridedElementPtr(loc, ptrType, memRefDesc, indices, strides,
offset, rewriter);
}
/// Only retain those attributes that are not constructed by
/// `LLVMFuncOp::build`. If `filterArgAttrs` is set, also filter out argument
/// attributes.
static void filterFuncAttributes(ArrayRef<NamedAttribute> attrs,
bool filterArgAttrs,
SmallVectorImpl<NamedAttribute> &result) {
for (const auto &attr : attrs) {
if (attr.first == SymbolTable::getSymbolAttrName() ||
attr.first == impl::getTypeAttrName() || attr.first == "std.varargs" ||
(filterArgAttrs && impl::isArgAttrName(attr.first.strref())))
continue;
result.push_back(attr);
}
}
/// Creates an auxiliary function with pointer-to-memref-descriptor-struct
/// arguments instead of unpacked arguments. This function can be called from C
/// by passing a pointer to a C struct corresponding to a memref descriptor.
/// Internally, the auxiliary function unpacks the descriptor into individual
/// components and forwards them to `newFuncOp`.
static void wrapForExternalCallers(OpBuilder &rewriter, Location loc,
LLVMTypeConverter &typeConverter,
FuncOp funcOp, LLVM::LLVMFuncOp newFuncOp) {
auto type = funcOp.getType();
SmallVector<NamedAttribute, 4> attributes;
filterFuncAttributes(funcOp.getAttrs(), /*filterArgAttrs=*/false, attributes);
auto wrapperFuncOp = rewriter.create<LLVM::LLVMFuncOp>(
loc, llvm::formatv("_mlir_ciface_{0}", funcOp.getName()).str(),
typeConverter.convertFunctionTypeCWrapper(type), LLVM::Linkage::External,
attributes);
OpBuilder::InsertionGuard guard(rewriter);
rewriter.setInsertionPointToStart(wrapperFuncOp.addEntryBlock());
SmallVector<Value, 8> args;
for (auto &en : llvm::enumerate(type.getInputs())) {
Value arg = wrapperFuncOp.getArgument(en.index());
if (auto memrefType = en.value().dyn_cast<MemRefType>()) {
Value loaded = rewriter.create<LLVM::LoadOp>(loc, arg);
MemRefDescriptor::unpack(rewriter, loc, loaded, memrefType, args);
continue;
}
if (en.value().isa<UnrankedMemRefType>()) {
Value loaded = rewriter.create<LLVM::LoadOp>(loc, arg);
UnrankedMemRefDescriptor::unpack(rewriter, loc, loaded, args);
continue;
}
args.push_back(wrapperFuncOp.getArgument(en.index()));
}
auto call = rewriter.create<LLVM::CallOp>(loc, newFuncOp, args);
rewriter.create<LLVM::ReturnOp>(loc, call.getResults());
}
/// Creates an auxiliary function with pointer-to-memref-descriptor-struct
/// arguments instead of unpacked arguments. Creates a body for the (external)
/// `newFuncOp` that allocates a memref descriptor on stack, packs the
/// individual arguments into this descriptor and passes a pointer to it into
/// the auxiliary function. This auxiliary external function is now compatible
/// with functions defined in C using pointers to C structs corresponding to a
/// memref descriptor.
static void wrapExternalFunction(OpBuilder &builder, Location loc,
LLVMTypeConverter &typeConverter,
FuncOp funcOp, LLVM::LLVMFuncOp newFuncOp) {
OpBuilder::InsertionGuard guard(builder);
LLVM::LLVMType wrapperType =
typeConverter.convertFunctionTypeCWrapper(funcOp.getType());
// This conversion can only fail if it could not convert one of the argument
// types. But since it has been applies to a non-wrapper function before, it
// should have failed earlier and not reach this point at all.
assert(wrapperType && "unexpected type conversion failure");
SmallVector<NamedAttribute, 4> attributes;
filterFuncAttributes(funcOp.getAttrs(), /*filterArgAttrs=*/false, attributes);
// Create the auxiliary function.
auto wrapperFunc = builder.create<LLVM::LLVMFuncOp>(
loc, llvm::formatv("_mlir_ciface_{0}", funcOp.getName()).str(),
wrapperType, LLVM::Linkage::External, attributes);
builder.setInsertionPointToStart(newFuncOp.addEntryBlock());
// Get a ValueRange containing arguments.
FunctionType type = funcOp.getType();
SmallVector<Value, 8> args;
args.reserve(type.getNumInputs());
ValueRange wrapperArgsRange(newFuncOp.getArguments());
// Iterate over the inputs of the original function and pack values into
// memref descriptors if the original type is a memref.
for (auto &en : llvm::enumerate(type.getInputs())) {
Value arg;
int numToDrop = 1;
auto memRefType = en.value().dyn_cast<MemRefType>();
auto unrankedMemRefType = en.value().dyn_cast<UnrankedMemRefType>();
if (memRefType || unrankedMemRefType) {
numToDrop = memRefType
? MemRefDescriptor::getNumUnpackedValues(memRefType)
: UnrankedMemRefDescriptor::getNumUnpackedValues();
Value packed =
memRefType
? MemRefDescriptor::pack(builder, loc, typeConverter, memRefType,
wrapperArgsRange.take_front(numToDrop))
: UnrankedMemRefDescriptor::pack(
builder, loc, typeConverter, unrankedMemRefType,
wrapperArgsRange.take_front(numToDrop));
auto ptrTy = packed.getType().cast<LLVM::LLVMType>().getPointerTo();
Value one = builder.create<LLVM::ConstantOp>(
loc, typeConverter.convertType(builder.getIndexType()),
builder.getIntegerAttr(builder.getIndexType(), 1));
Value allocated =
builder.create<LLVM::AllocaOp>(loc, ptrTy, one, /*alignment=*/0);
builder.create<LLVM::StoreOp>(loc, packed, allocated);
arg = allocated;
} else {
arg = wrapperArgsRange[0];
}
args.push_back(arg);
wrapperArgsRange = wrapperArgsRange.drop_front(numToDrop);
}
assert(wrapperArgsRange.empty() && "did not map some of the arguments");
auto call = builder.create<LLVM::CallOp>(loc, wrapperFunc, args);
builder.create<LLVM::ReturnOp>(loc, call.getResults());
}
namespace {
struct FuncOpConversionBase : public ConvertOpToLLVMPattern<FuncOp> {
protected:
using ConvertOpToLLVMPattern<FuncOp>::ConvertOpToLLVMPattern;
using UnsignedTypePair = std::pair<unsigned, Type>;
// Gather the positions and types of memref-typed arguments in a given
// FunctionType.
void getMemRefArgIndicesAndTypes(
FunctionType type, SmallVectorImpl<UnsignedTypePair> &argsInfo) const {
argsInfo.reserve(type.getNumInputs());
for (auto en : llvm::enumerate(type.getInputs())) {
if (en.value().isa<MemRefType, UnrankedMemRefType>())
argsInfo.push_back({en.index(), en.value()});
}
}
// Convert input FuncOp to LLVMFuncOp by using the LLVMTypeConverter provided
// to this legalization pattern.
LLVM::LLVMFuncOp
convertFuncOpToLLVMFuncOp(FuncOp funcOp,
ConversionPatternRewriter &rewriter) const {
// Convert the original function arguments. They are converted using the
// LLVMTypeConverter provided to this legalization pattern.
auto varargsAttr = funcOp.getAttrOfType<BoolAttr>("std.varargs");
TypeConverter::SignatureConversion result(funcOp.getNumArguments());
auto llvmType = typeConverter.convertFunctionSignature(
funcOp.getType(), varargsAttr && varargsAttr.getValue(), result);
// Propagate argument attributes to all converted arguments obtained after
// converting a given original argument.
SmallVector<NamedAttribute, 4> attributes;
filterFuncAttributes(funcOp.getAttrs(), /*filterArgAttrs=*/true,
attributes);
for (unsigned i = 0, e = funcOp.getNumArguments(); i < e; ++i) {
auto attr = impl::getArgAttrDict(funcOp, i);
if (!attr)
continue;
auto mapping = result.getInputMapping(i);
assert(mapping.hasValue() && "unexpected deletion of function argument");
SmallString<8> name;
for (size_t j = 0; j < mapping->size; ++j) {
impl::getArgAttrName(mapping->inputNo + j, name);
attributes.push_back(rewriter.getNamedAttr(name, attr));
}
}
// Create an LLVM function, use external linkage by default until MLIR
// functions have linkage.
auto newFuncOp = rewriter.create<LLVM::LLVMFuncOp>(
funcOp.getLoc(), funcOp.getName(), llvmType, LLVM::Linkage::External,
attributes);
rewriter.inlineRegionBefore(funcOp.getBody(), newFuncOp.getBody(),
newFuncOp.end());
if (failed(rewriter.convertRegionTypes(&newFuncOp.getBody(), typeConverter,
&result)))
return nullptr;
return newFuncOp;
}
};
/// FuncOp legalization pattern that converts MemRef arguments to pointers to
/// MemRef descriptors (LLVM struct data types) containing all the MemRef type
/// information.
static constexpr StringRef kEmitIfaceAttrName = "llvm.emit_c_interface";
struct FuncOpConversion : public FuncOpConversionBase {
FuncOpConversion(LLVMTypeConverter &converter,
const LowerToLLVMOptions &options)
: FuncOpConversionBase(converter, options) {}
using ConvertOpToLLVMPattern<FuncOp>::options;
LogicalResult
matchAndRewrite(Operation *op, ArrayRef<Value> operands,
ConversionPatternRewriter &rewriter) const override {
auto funcOp = cast<FuncOp>(op);
auto newFuncOp = convertFuncOpToLLVMFuncOp(funcOp, rewriter);
if (!newFuncOp)
return failure();
if (options.emitCWrappers ||
funcOp.getAttrOfType<UnitAttr>(kEmitIfaceAttrName)) {
if (newFuncOp.isExternal())
wrapExternalFunction(rewriter, op->getLoc(), typeConverter, funcOp,
newFuncOp);
else
wrapForExternalCallers(rewriter, op->getLoc(), typeConverter, funcOp,
newFuncOp);
}
rewriter.eraseOp(op);
return success();
}
};
/// FuncOp legalization pattern that converts MemRef arguments to bare pointers
/// to the MemRef element type. This will impact the calling convention and ABI.
struct BarePtrFuncOpConversion : public FuncOpConversionBase {
using FuncOpConversionBase::FuncOpConversionBase;
LogicalResult
matchAndRewrite(Operation *op, ArrayRef<Value> operands,
ConversionPatternRewriter &rewriter) const override {
auto funcOp = cast<FuncOp>(op);
// Store the positions and type of memref-typed arguments so that we can
// promote them to MemRef descriptor structs at the beginning of the
// function.
SmallVector<UnsignedTypePair, 4> promotedArgsInfo;
getMemRefArgIndicesAndTypes(funcOp.getType(), promotedArgsInfo);
auto newFuncOp = convertFuncOpToLLVMFuncOp(funcOp, rewriter);
if (!newFuncOp)
return failure();
if (newFuncOp.getBody().empty()) {
rewriter.eraseOp(op);
return success();
}
// Promote bare pointers from MemRef arguments to a MemRef descriptor struct
// at the beginning of the function so that all the MemRefs in the function
// have a uniform representation.
Block *firstBlock = &newFuncOp.getBody().front();
rewriter.setInsertionPoint(firstBlock, firstBlock->begin());
auto funcLoc = funcOp.getLoc();
for (const auto &argInfo : promotedArgsInfo) {
// TODO: Add support for unranked MemRefs.
if (auto memrefType = argInfo.second.dyn_cast<MemRefType>()) {
// Replace argument with a placeholder (undef), promote argument to a
// MemRef descriptor and replace placeholder with the last instruction
// of the MemRef descriptor. The placeholder is needed to avoid
// replacing argument uses in the MemRef descriptor instructions.
BlockArgument arg = firstBlock->getArgument(argInfo.first);
Value placeHolder =
rewriter.create<LLVM::UndefOp>(funcLoc, arg.getType());
rewriter.replaceUsesOfBlockArgument(arg, placeHolder);
auto desc = MemRefDescriptor::fromStaticShape(
rewriter, funcLoc, typeConverter, memrefType, arg);
rewriter.replaceOp(placeHolder.getDefiningOp(), {desc});
}
}
rewriter.eraseOp(op);
return success();
}
};
//////////////// Support for Lowering operations on n-D vectors ////////////////
// Helper struct to "unroll" operations on n-D vectors in terms of operations on
// 1-D LLVM vectors.
struct NDVectorTypeInfo {
// LLVM array struct which encodes n-D vectors.
LLVM::LLVMType llvmArrayTy;
// LLVM vector type which encodes the inner 1-D vector type.
LLVM::LLVMType llvmVectorTy;
// Multiplicity of llvmArrayTy to llvmVectorTy.
SmallVector<int64_t, 4> arraySizes;
};
} // namespace
// For >1-D vector types, extracts the necessary information to iterate over all
// 1-D subvectors in the underlying llrepresentation of the n-D vector
// Iterates on the llvm array type until we hit a non-array type (which is
// asserted to be an llvm vector type).
static NDVectorTypeInfo extractNDVectorTypeInfo(VectorType vectorType,
LLVMTypeConverter &converter) {
assert(vectorType.getRank() > 1 && "expected >1D vector type");
NDVectorTypeInfo info;
info.llvmArrayTy =
converter.convertType(vectorType).dyn_cast<LLVM::LLVMType>();
if (!info.llvmArrayTy)
return info;
info.arraySizes.reserve(vectorType.getRank() - 1);
auto llvmTy = info.llvmArrayTy;
while (llvmTy.isArrayTy()) {
info.arraySizes.push_back(llvmTy.getArrayNumElements());
llvmTy = llvmTy.getArrayElementType();
}
if (!llvmTy.isVectorTy())
return info;
info.llvmVectorTy = llvmTy;
return info;
}
// Express `linearIndex` in terms of coordinates of `basis`.
// Returns the empty vector when linearIndex is out of the range [0, P] where
// P is the product of all the basis coordinates.
//
// Prerequisites:
// Basis is an array of nonnegative integers (signed type inherited from
// vector shape type).
static SmallVector<int64_t, 4> getCoordinates(ArrayRef<int64_t> basis,
unsigned linearIndex) {
SmallVector<int64_t, 4> res;
res.reserve(basis.size());
for (unsigned basisElement : llvm::reverse(basis)) {
res.push_back(linearIndex % basisElement);
linearIndex = linearIndex / basisElement;
}
if (linearIndex > 0)
return {};
std::reverse(res.begin(), res.end());
return res;
}
// Iterate of linear index, convert to coords space and insert splatted 1-D
// vector in each position.
template <typename Lambda>
void nDVectorIterate(const NDVectorTypeInfo &info, OpBuilder &builder,
Lambda fun) {
unsigned ub = 1;
for (auto s : info.arraySizes)
ub *= s;
for (unsigned linearIndex = 0; linearIndex < ub; ++linearIndex) {
auto coords = getCoordinates(info.arraySizes, linearIndex);
// Linear index is out of bounds, we are done.
if (coords.empty())
break;
assert(coords.size() == info.arraySizes.size());
auto position = builder.getI64ArrayAttr(coords);
fun(position);
}
}
////////////// End Support for Lowering operations on n-D vectors //////////////
/// Replaces the given operation "op" with a new operation of type "targetOp"
/// and given operands.
LogicalResult LLVM::detail::oneToOneRewrite(
Operation *op, StringRef targetOp, ValueRange operands,
LLVMTypeConverter &typeConverter, ConversionPatternRewriter &rewriter) {
unsigned numResults = op->getNumResults();
Type packedType;
if (numResults != 0) {
packedType = typeConverter.packFunctionResults(op->getResultTypes());
if (!packedType)
return failure();
}
// Create the operation through state since we don't know its C++ type.
OperationState state(op->getLoc(), targetOp);
state.addTypes(packedType);
state.addOperands(operands);
state.addAttributes(op->getAttrs());
Operation *newOp = rewriter.createOperation(state);
// If the operation produced 0 or 1 result, return them immediately.
if (numResults == 0)
return rewriter.eraseOp(op), success();
if (numResults == 1)
return rewriter.replaceOp(op, newOp->getResult(0)), success();
// Otherwise, it had been converted to an operation producing a structure.
// Extract individual results from the structure and return them as list.
SmallVector<Value, 4> results;
results.reserve(numResults);
for (unsigned i = 0; i < numResults; ++i) {
auto type = typeConverter.convertType(op->getResult(i).getType());
results.push_back(rewriter.create<LLVM::ExtractValueOp>(
op->getLoc(), type, newOp->getResult(0), rewriter.getI64ArrayAttr(i)));
}
rewriter.replaceOp(op, results);
return success();
}
static LogicalResult handleMultidimensionalVectors(
Operation *op, ValueRange operands, LLVMTypeConverter &typeConverter,
std::function<Value(LLVM::LLVMType, ValueRange)> createOperand,
ConversionPatternRewriter &rewriter) {
auto vectorType = op->getResult(0).getType().dyn_cast<VectorType>();
if (!vectorType)
return failure();
auto vectorTypeInfo = extractNDVectorTypeInfo(vectorType, typeConverter);
auto llvmVectorTy = vectorTypeInfo.llvmVectorTy;
auto llvmArrayTy = operands[0].getType().cast<LLVM::LLVMType>();
if (!llvmVectorTy || llvmArrayTy != vectorTypeInfo.llvmArrayTy)
return failure();
auto loc = op->getLoc();
Value desc = rewriter.create<LLVM::UndefOp>(loc, llvmArrayTy);
nDVectorIterate(vectorTypeInfo, rewriter, [&](ArrayAttr position) {
// For this unrolled `position` corresponding to the `linearIndex`^th
// element, extract operand vectors
SmallVector<Value, 4> extractedOperands;
for (auto operand : operands)
extractedOperands.push_back(rewriter.create<LLVM::ExtractValueOp>(
loc, llvmVectorTy, operand, position));
Value newVal = createOperand(llvmVectorTy, extractedOperands);
desc = rewriter.create<LLVM::InsertValueOp>(loc, llvmArrayTy, desc, newVal,
position);
});
rewriter.replaceOp(op, desc);
return success();
}
LogicalResult LLVM::detail::vectorOneToOneRewrite(
Operation *op, StringRef targetOp, ValueRange operands,
LLVMTypeConverter &typeConverter, ConversionPatternRewriter &rewriter) {
assert(!operands.empty());
// Cannot convert ops if their operands are not of LLVM type.
if (!llvm::all_of(operands.getTypes(),
[](Type t) { return t.isa<LLVM::LLVMType>(); }))
return failure();
auto llvmArrayTy = operands[0].getType().cast<LLVM::LLVMType>();
if (!llvmArrayTy.isArrayTy())
return oneToOneRewrite(op, targetOp, operands, typeConverter, rewriter);
auto callback = [op, targetOp, &rewriter](LLVM::LLVMType llvmVectorTy,
ValueRange operands) {
OperationState state(op->getLoc(), targetOp);
state.addTypes(llvmVectorTy);
state.addOperands(operands);
state.addAttributes(op->getAttrs());
return rewriter.createOperation(state)->getResult(0);
};
return handleMultidimensionalVectors(op, operands, typeConverter, callback,
rewriter);
}
namespace {
// Straightforward lowerings.
using AbsFOpLowering = VectorConvertToLLVMPattern<AbsFOp, LLVM::FAbsOp>;
using AddFOpLowering = VectorConvertToLLVMPattern<AddFOp, LLVM::FAddOp>;
using AddIOpLowering = VectorConvertToLLVMPattern<AddIOp, LLVM::AddOp>;
using AndOpLowering = VectorConvertToLLVMPattern<AndOp, LLVM::AndOp>;
using CeilFOpLowering = VectorConvertToLLVMPattern<CeilFOp, LLVM::FCeilOp>;
using CopySignOpLowering =
VectorConvertToLLVMPattern<CopySignOp, LLVM::CopySignOp>;
using CosOpLowering = VectorConvertToLLVMPattern<CosOp, LLVM::CosOp>;
using DivFOpLowering = VectorConvertToLLVMPattern<DivFOp, LLVM::FDivOp>;
using ExpOpLowering = VectorConvertToLLVMPattern<ExpOp, LLVM::ExpOp>;
using Exp2OpLowering = VectorConvertToLLVMPattern<Exp2Op, LLVM::Exp2Op>;
using Log10OpLowering = VectorConvertToLLVMPattern<Log10Op, LLVM::Log10Op>;
using Log2OpLowering = VectorConvertToLLVMPattern<Log2Op, LLVM::Log2Op>;
using LogOpLowering = VectorConvertToLLVMPattern<LogOp, LLVM::LogOp>;
using MulFOpLowering = VectorConvertToLLVMPattern<MulFOp, LLVM::FMulOp>;
using MulIOpLowering = VectorConvertToLLVMPattern<MulIOp, LLVM::MulOp>;
using NegFOpLowering = VectorConvertToLLVMPattern<NegFOp, LLVM::FNegOp>;
using OrOpLowering = VectorConvertToLLVMPattern<OrOp, LLVM::OrOp>;
using RemFOpLowering = VectorConvertToLLVMPattern<RemFOp, LLVM::FRemOp>;
using SelectOpLowering = OneToOneConvertToLLVMPattern<SelectOp, LLVM::SelectOp>;
using ShiftLeftOpLowering =
OneToOneConvertToLLVMPattern<ShiftLeftOp, LLVM::ShlOp>;
using SignedDivIOpLowering =
VectorConvertToLLVMPattern<SignedDivIOp, LLVM::SDivOp>;
using SignedRemIOpLowering =
VectorConvertToLLVMPattern<SignedRemIOp, LLVM::SRemOp>;
using SignedShiftRightOpLowering =
OneToOneConvertToLLVMPattern<SignedShiftRightOp, LLVM::AShrOp>;
using SinOpLowering = VectorConvertToLLVMPattern<SinOp, LLVM::SinOp>;
using SqrtOpLowering = VectorConvertToLLVMPattern<SqrtOp, LLVM::SqrtOp>;
using SubFOpLowering = VectorConvertToLLVMPattern<SubFOp, LLVM::FSubOp>;
using SubIOpLowering = VectorConvertToLLVMPattern<SubIOp, LLVM::SubOp>;
using UnsignedDivIOpLowering =
VectorConvertToLLVMPattern<UnsignedDivIOp, LLVM::UDivOp>;
using UnsignedRemIOpLowering =
VectorConvertToLLVMPattern<UnsignedRemIOp, LLVM::URemOp>;
using UnsignedShiftRightOpLowering =
OneToOneConvertToLLVMPattern<UnsignedShiftRightOp, LLVM::LShrOp>;
using XOrOpLowering = VectorConvertToLLVMPattern<XOrOp, LLVM::XOrOp>;
// Lowerings for operations on complex numbers.
struct CreateComplexOpLowering
: public ConvertOpToLLVMPattern<CreateComplexOp> {
using ConvertOpToLLVMPattern<CreateComplexOp>::ConvertOpToLLVMPattern;
LogicalResult
matchAndRewrite(Operation *op, ArrayRef<Value> operands,
ConversionPatternRewriter &rewriter) const override {
auto complexOp = cast<CreateComplexOp>(op);
CreateComplexOp::Adaptor transformed(operands);
// Pack real and imaginary part in a complex number struct.
auto loc = op->getLoc();
auto structType = typeConverter.convertType(complexOp.getType());
auto complexStruct = ComplexStructBuilder::undef(rewriter, loc, structType);
complexStruct.setReal(rewriter, loc, transformed.real());
complexStruct.setImaginary(rewriter, loc, transformed.imaginary());
rewriter.replaceOp(op, {complexStruct});
return success();
}
};
struct ReOpLowering : public ConvertOpToLLVMPattern<ReOp> {
using ConvertOpToLLVMPattern<ReOp>::ConvertOpToLLVMPattern;
LogicalResult
matchAndRewrite(Operation *op, ArrayRef<Value> operands,
ConversionPatternRewriter &rewriter) const override {
ReOp::Adaptor transformed(operands);
// Extract real part from the complex number struct.
ComplexStructBuilder complexStruct(transformed.complex());
Value real = complexStruct.real(rewriter, op->getLoc());
rewriter.replaceOp(op, real);
return success();
}
};
struct ImOpLowering : public ConvertOpToLLVMPattern<ImOp> {
using ConvertOpToLLVMPattern<ImOp>::ConvertOpToLLVMPattern;
LogicalResult
matchAndRewrite(Operation *op, ArrayRef<Value> operands,
ConversionPatternRewriter &rewriter) const override {
ImOp::Adaptor transformed(operands);
// Extract imaginary part from the complex number struct.
ComplexStructBuilder complexStruct(transformed.complex());
Value imaginary = complexStruct.imaginary(rewriter, op->getLoc());
rewriter.replaceOp(op, imaginary);
return success();
}
};
struct BinaryComplexOperands {
std::complex<Value> lhs, rhs;
};
template <typename OpTy>
BinaryComplexOperands
unpackBinaryComplexOperands(OpTy op, ArrayRef<Value> operands,
ConversionPatternRewriter &rewriter) {
auto bop = cast<OpTy>(op);
auto loc = bop.getLoc();
typename OpTy::Adaptor transformed(operands);
// Extract real and imaginary values from operands.
BinaryComplexOperands unpacked;
ComplexStructBuilder lhs(transformed.lhs());
unpacked.lhs.real(lhs.real(rewriter, loc));
unpacked.lhs.imag(lhs.imaginary(rewriter, loc));
ComplexStructBuilder rhs(transformed.rhs());
unpacked.rhs.real(rhs.real(rewriter, loc));
unpacked.rhs.imag(rhs.imaginary(rewriter, loc));
return unpacked;
}
struct AddCFOpLowering : public ConvertOpToLLVMPattern<AddCFOp> {
using ConvertOpToLLVMPattern<AddCFOp>::ConvertOpToLLVMPattern;
LogicalResult
matchAndRewrite(Operation *operation, ArrayRef<Value> operands,
ConversionPatternRewriter &rewriter) const override {
auto op = cast<AddCFOp>(operation);
auto loc = op.getLoc();
BinaryComplexOperands arg =
unpackBinaryComplexOperands<AddCFOp>(op, operands, rewriter);
// Initialize complex number struct for result.
auto structType = this->typeConverter.convertType(op.getType());
auto result = ComplexStructBuilder::undef(rewriter, loc, structType);
// Emit IR to add complex numbers.
Value real =
rewriter.create<LLVM::FAddOp>(loc, arg.lhs.real(), arg.rhs.real());
Value imag =
rewriter.create<LLVM::FAddOp>(loc, arg.lhs.imag(), arg.rhs.imag());
result.setReal(rewriter, loc, real);
result.setImaginary(rewriter, loc, imag);
rewriter.replaceOp(op, {result});
return success();
}
};
struct SubCFOpLowering : public ConvertOpToLLVMPattern<SubCFOp> {
using ConvertOpToLLVMPattern<SubCFOp>::ConvertOpToLLVMPattern;
LogicalResult
matchAndRewrite(Operation *operation, ArrayRef<Value> operands,
ConversionPatternRewriter &rewriter) const override {
auto op = cast<SubCFOp>(operation);
auto loc = op.getLoc();
BinaryComplexOperands arg =
unpackBinaryComplexOperands<SubCFOp>(op, operands, rewriter);
// Initialize complex number struct for result.
auto structType = this->typeConverter.convertType(op.getType());
auto result = ComplexStructBuilder::undef(rewriter, loc, structType);
// Emit IR to substract complex numbers.
Value real =
rewriter.create<LLVM::FSubOp>(loc, arg.lhs.real(), arg.rhs.real());
Value imag =
rewriter.create<LLVM::FSubOp>(loc, arg.lhs.imag(), arg.rhs.imag());
result.setReal(rewriter, loc, real);
result.setImaginary(rewriter, loc, imag);
rewriter.replaceOp(op, {result});
return success();
}
};
struct ConstantOpLowering : public ConvertOpToLLVMPattern<ConstantOp> {
using ConvertOpToLLVMPattern<ConstantOp>::ConvertOpToLLVMPattern;
LogicalResult
matchAndRewrite(Operation *operation, ArrayRef<Value> operands,
ConversionPatternRewriter &rewriter) const override {
auto op = cast<ConstantOp>(operation);
// If constant refers to a function, convert it to "addressof".
if (auto symbolRef = op.getValue().dyn_cast<FlatSymbolRefAttr>()) {
auto type = typeConverter.convertType(op.getResult().getType())
.dyn_cast_or_null<LLVM::LLVMType>();
if (!type)
return rewriter.notifyMatchFailure(op, "failed to convert result type");
MutableDictionaryAttr attrs(op.getAttrs());
attrs.remove(rewriter.getIdentifier("value"));
rewriter.replaceOpWithNewOp<LLVM::AddressOfOp>(
op, type.cast<LLVM::LLVMType>(), symbolRef.getValue(),
attrs.getAttrs());
return success();
}
// Calling into other scopes (non-flat reference) is not supported in LLVM.
if (op.getValue().isa<SymbolRefAttr>())
return rewriter.notifyMatchFailure(
op, "referring to a symbol outside of the current module");
return LLVM::detail::oneToOneRewrite(op,
LLVM::ConstantOp::getOperationName(),
operands, typeConverter, rewriter);
}
};
// Check if the MemRefType `type` is supported by the lowering. We currently
// only support memrefs with identity maps.
static bool isSupportedMemRefType(MemRefType type) {
return type.getAffineMaps().empty() ||
llvm::all_of(type.getAffineMaps(),
[](AffineMap map) { return map.isIdentity(); });
}
/// Lowering for AllocOp and AllocaOp.
template <typename AllocLikeOp>
struct AllocLikeOpLowering : public ConvertOpToLLVMPattern<AllocLikeOp> {
using ConvertOpToLLVMPattern<AllocLikeOp>::createIndexConstant;
using ConvertOpToLLVMPattern<AllocLikeOp>::getIndexType;
using ConvertOpToLLVMPattern<AllocLikeOp>::typeConverter;
using ConvertOpToLLVMPattern<AllocLikeOp>::getVoidPtrType;
using ConvertOpToLLVMPattern<AllocLikeOp>::options;
explicit AllocLikeOpLowering(LLVMTypeConverter &converter,
const LowerToLLVMOptions &options)
: ConvertOpToLLVMPattern<AllocLikeOp>(converter, options) {}
LogicalResult match(Operation *op) const override {
MemRefType memRefType = cast<AllocLikeOp>(op).getType();
if (isSupportedMemRefType(memRefType))
return success();
int64_t offset;
SmallVector<int64_t, 4> strides;
auto successStrides = getStridesAndOffset(memRefType, strides, offset);
if (failed(successStrides))
return failure();
// Dynamic strides are ok if they can be deduced from dynamic sizes (which
// is guaranteed when succeeded(successStrides)). Dynamic offset however can
// never be alloc'ed.
if (offset == MemRefType::getDynamicStrideOrOffset())
return failure();
return success();
}
// Returns bump = (alignment - (input % alignment))% alignment, which is the
// increment necessary to align `input` to `alignment` boundary.
// TODO: this can be made more efficient by just using a single addition
// and two bit shifts: (ptr + align - 1)/align, align is always power of 2.
Value createBumpToAlign(Location loc, OpBuilder b, Value input,
Value alignment) const {
Value modAlign = b.create<LLVM::URemOp>(loc, input, alignment);
Value diff = b.create<LLVM::SubOp>(loc, alignment, modAlign);
Value shift = b.create<LLVM::URemOp>(loc, diff, alignment);
return shift;
}
/// Creates and populates the memref descriptor struct given all its fields.
/// This method also performs any post allocation alignment needed for heap
/// allocations when `accessAlignment` is non null. This is used with
/// allocators that do not support alignment.
MemRefDescriptor createMemRefDescriptor(
Location loc, ConversionPatternRewriter &rewriter, MemRefType memRefType,
Value allocatedTypePtr, Value allocatedBytePtr, Value accessAlignment,
uint64_t offset, ArrayRef<int64_t> strides, ArrayRef<Value> sizes) const {
auto elementPtrType = getElementPtrType(memRefType);
auto structType = typeConverter.convertType(memRefType);
auto memRefDescriptor = MemRefDescriptor::undef(rewriter, loc, structType);
// Field 1: Allocated pointer, used for malloc/free.
memRefDescriptor.setAllocatedPtr(rewriter, loc, allocatedTypePtr);
// Field 2: Actual aligned pointer to payload.
Value alignedBytePtr = allocatedTypePtr;
if (accessAlignment) {
// offset = (align - (ptr % align))% align
Value intVal = rewriter.create<LLVM::PtrToIntOp>(
loc, this->getIndexType(), allocatedBytePtr);
Value offset = createBumpToAlign(loc, rewriter, intVal, accessAlignment);
Value aligned = rewriter.create<LLVM::GEPOp>(
loc, allocatedBytePtr.getType(), allocatedBytePtr, offset);
alignedBytePtr = rewriter.create<LLVM::BitcastOp>(
loc, elementPtrType, ArrayRef<Value>(aligned));
}
memRefDescriptor.setAlignedPtr(rewriter, loc, alignedBytePtr);
// Field 3: Offset in aligned pointer.
memRefDescriptor.setOffset(rewriter, loc,
createIndexConstant(rewriter, loc, offset));
if (memRefType.getRank() == 0)
// No size/stride descriptor in memref, return the descriptor value.
return memRefDescriptor;
// Fields 4 and 5: sizes and strides of the strided MemRef.
// Store all sizes in the descriptor. Only dynamic sizes are passed in as
// operands to AllocOp.
Value runningStride = nullptr;
// Iterate strides in reverse order, compute runningStride and strideValues.
auto nStrides = strides.size();
SmallVector<Value, 4> strideValues(nStrides, nullptr);
for (unsigned i = 0; i < nStrides; ++i) {
int64_t index = nStrides - 1 - i;
if (strides[index] == MemRefType::getDynamicStrideOrOffset())
// Identity layout map is enforced in the match function, so we compute:
// `runningStride *= sizes[index + 1]`
runningStride = runningStride
? rewriter.create<LLVM::MulOp>(loc, runningStride,
sizes[index + 1])
: createIndexConstant(rewriter, loc, 1);
else
runningStride = createIndexConstant(rewriter, loc, strides[index]);
strideValues[index] = runningStride;
}
// Fill size and stride descriptors in memref.
for (auto indexedSize : llvm::enumerate(sizes)) {
int64_t index = indexedSize.index();
memRefDescriptor.setSize(rewriter, loc, index, indexedSize.value());
memRefDescriptor.setStride(rewriter, loc, index, strideValues[index]);
}
return memRefDescriptor;
}
/// Determines sizes to be used in the memref descriptor.
void getSizes(Location loc, MemRefType memRefType, ArrayRef<Value> operands,
ConversionPatternRewriter &rewriter,
SmallVectorImpl<Value> &sizes, Value &cumulativeSize,
Value &one) const {
sizes.reserve(memRefType.getRank());
unsigned i = 0;
for (int64_t s : memRefType.getShape())
sizes.push_back(s == -1 ? operands[i++]
: createIndexConstant(rewriter, loc, s));
if (sizes.empty())
sizes.push_back(createIndexConstant(rewriter, loc, 1));
// Compute the total number of memref elements.
cumulativeSize = sizes.front();
for (unsigned i = 1, e = sizes.size(); i < e; ++i)
cumulativeSize = rewriter.create<LLVM::MulOp>(
loc, getIndexType(), ArrayRef<Value>{cumulativeSize, sizes[i]});
// Compute the size of an individual element. This emits the MLIR equivalent
// of the following sizeof(...) implementation in LLVM IR:
// %0 = getelementptr %elementType* null, %indexType 1
// %1 = ptrtoint %elementType* %0 to %indexType
// which is a common pattern of getting the size of a type in bytes.
auto elementType = memRefType.getElementType();
auto convertedPtrType = typeConverter.convertType(elementType)
.template cast<LLVM::LLVMType>()
.getPointerTo();
auto nullPtr = rewriter.create<LLVM::NullOp>(loc, convertedPtrType);
one = createIndexConstant(rewriter, loc, 1);
auto gep = rewriter.create<LLVM::GEPOp>(loc, convertedPtrType,
ArrayRef<Value>{nullPtr, one});
auto elementSize =
rewriter.create<LLVM::PtrToIntOp>(loc, getIndexType(), gep);
cumulativeSize = rewriter.create<LLVM::MulOp>(
loc, getIndexType(), ArrayRef<Value>{cumulativeSize, elementSize});
}
/// Returns the type of a pointer to an element of the memref.
Type getElementPtrType(MemRefType memRefType) const {
auto elementType = memRefType.getElementType();
auto structElementType = typeConverter.convertType(elementType);
return structElementType.template cast<LLVM::LLVMType>().getPointerTo(
memRefType.getMemorySpace());
}
/// Returns the memref's element size in bytes.
// TODO: there are other places where this is used. Expose publicly?
static unsigned getMemRefEltSizeInBytes(MemRefType memRefType) {
auto elementType = memRefType.getElementType();
unsigned sizeInBits;
if (elementType.isIntOrFloat()) {
sizeInBits = elementType.getIntOrFloatBitWidth();
} else {
auto vectorType = elementType.cast<VectorType>();
sizeInBits =
vectorType.getElementTypeBitWidth() * vectorType.getNumElements();
}
return llvm::divideCeil(sizeInBits, 8);
}
/// Returns the alignment to be used for the allocation call itself.
/// aligned_alloc requires the allocation size to be a power of two, and the
/// allocation size to be a multiple of alignment,
Optional<int64_t> getAllocationAlignment(AllocOp allocOp) const {
// No alignment can be used for the 'malloc' call itself.
if (!options.useAlignedAlloc)
return None;
if (allocOp.alignment())
return allocOp.alignment().getValue().getSExtValue();
// Whenever we don't have alignment set, we will use an alignment
// consistent with the element type; since the allocation size has to be a
// power of two, we will bump to the next power of two if it already isn't.
auto eltSizeBytes = getMemRefEltSizeInBytes(allocOp.getType());
return std::max(kMinAlignedAllocAlignment,
llvm::PowerOf2Ceil(eltSizeBytes));
}
/// Returns true if the memref size in bytes is known to be a multiple of
/// factor.
static bool isMemRefSizeMultipleOf(MemRefType type, uint64_t factor) {
uint64_t sizeDivisor = getMemRefEltSizeInBytes(type);
for (unsigned i = 0, e = type.getRank(); i < e; i++) {
if (type.isDynamic(type.getDimSize(i)))
continue;
sizeDivisor = sizeDivisor * type.getDimSize(i);
}
return sizeDivisor % factor == 0;
}
/// Allocates the underlying buffer using the right call. `allocatedBytePtr`
/// is set to null for stack allocations. `accessAlignment` is set if
/// alignment is needed post allocation (for eg. in conjunction with malloc).
Value allocateBuffer(Location loc, Value cumulativeSize, Operation *op,
MemRefType memRefType, Value one, Value &accessAlignment,
Value &allocatedBytePtr,
ConversionPatternRewriter &rewriter) const {
auto elementPtrType = getElementPtrType(memRefType);
// With alloca, one gets a pointer to the element type right away.
// For stack allocations.
if (auto allocaOp = dyn_cast<AllocaOp>(op)) {
allocatedBytePtr = nullptr;
accessAlignment = nullptr;
return rewriter.create<LLVM::AllocaOp>(
loc, elementPtrType, cumulativeSize,
allocaOp.alignment() ? allocaOp.alignment().getValue().getSExtValue()
: 0);
}
// Heap allocations.
AllocOp allocOp = cast<AllocOp>(op);
Optional<int64_t> allocationAlignment = getAllocationAlignment(allocOp);
// Whether to use std lib function aligned_alloc that supports alignment.
bool useAlignedAlloc = allocationAlignment.hasValue();
// Insert the malloc/aligned_alloc declaration if it is not already present.
auto allocFuncName = useAlignedAlloc ? "aligned_alloc" : "malloc";
auto module = allocOp.getParentOfType<ModuleOp>();
auto allocFunc = module.lookupSymbol<LLVM::LLVMFuncOp>(allocFuncName);
if (!allocFunc) {
OpBuilder::InsertionGuard guard(rewriter);
rewriter.setInsertionPointToStart(
op->getParentOfType<ModuleOp>().getBody());
SmallVector<LLVM::LLVMType, 2> callArgTypes = {getIndexType()};
// aligned_alloc(size_t alignment, size_t size)
if (useAlignedAlloc)
callArgTypes.push_back(getIndexType());
allocFunc = rewriter.create<LLVM::LLVMFuncOp>(
rewriter.getUnknownLoc(), allocFuncName,
LLVM::LLVMType::getFunctionTy(getVoidPtrType(), callArgTypes,
/*isVarArg=*/false));
}
// Allocate the underlying buffer and store a pointer to it in the MemRef
// descriptor.
SmallVector<Value, 2> callArgs;
if (useAlignedAlloc) {
// Use aligned_alloc.
assert(allocationAlignment && "allocation alignment should be present");
auto alignedAllocAlignmentValue = rewriter.create<LLVM::ConstantOp>(
loc, typeConverter.convertType(rewriter.getIntegerType(64)),
rewriter.getI64IntegerAttr(allocationAlignment.getValue()));
// aligned_alloc requires size to be a multiple of alignment; we will pad
// the size to the next multiple if necessary.
if (!isMemRefSizeMultipleOf(memRefType, allocationAlignment.getValue())) {
Value bump = createBumpToAlign(loc, rewriter, cumulativeSize,
alignedAllocAlignmentValue);
cumulativeSize =
rewriter.create<LLVM::AddOp>(loc, cumulativeSize, bump);
}
callArgs = {alignedAllocAlignmentValue, cumulativeSize};
} else {
// Adjust the allocation size to consider alignment.
if (allocOp.alignment()) {
accessAlignment = createIndexConstant(
rewriter, loc, allocOp.alignment().getValue().getSExtValue());
cumulativeSize = rewriter.create<LLVM::SubOp>(
loc,
rewriter.create<LLVM::AddOp>(loc, cumulativeSize, accessAlignment),
one);
}
callArgs.push_back(cumulativeSize);
}
auto allocFuncSymbol = rewriter.getSymbolRefAttr(allocFunc);
allocatedBytePtr = rewriter
.create<LLVM::CallOp>(loc, getVoidPtrType(),
allocFuncSymbol, callArgs)
.getResult(0);
// For heap allocations, the allocated pointer is a cast of the byte pointer
// to the type pointer.
return rewriter.create<LLVM::BitcastOp>(loc, elementPtrType,
allocatedBytePtr);
}
// An `alloc` is converted into a definition of a memref descriptor value and
// a call to `malloc` to allocate the underlying data buffer. The memref
// descriptor is of the LLVM structure type where:
// 1. the first element is a pointer to the allocated (typed) data buffer,
// 2. the second element is a pointer to the (typed) payload, aligned to the
// specified alignment,
// 3. the remaining elements serve to store all the sizes and strides of the
// memref using LLVM-converted `index` type.
//
// Alignment is performed by allocating `alignment - 1` more bytes than
// requested and shifting the aligned pointer relative to the allocated
// memory. If alignment is unspecified, the two pointers are equal.
// An `alloca` is converted into a definition of a memref descriptor value and
// an llvm.alloca to allocate the underlying data buffer.
void rewrite(Operation *op, ArrayRef<Value> operands,
ConversionPatternRewriter &rewriter) const override {
MemRefType memRefType = cast<AllocLikeOp>(op).getType();
auto loc = op->getLoc();
// Get actual sizes of the memref as values: static sizes are constant
// values and dynamic sizes are passed to 'alloc' as operands. In case of
// zero-dimensional memref, assume a scalar (size 1).
SmallVector<Value, 4> sizes;
Value cumulativeSize, one;
getSizes(loc, memRefType, operands, rewriter, sizes, cumulativeSize, one);
// Allocate the underlying buffer.
// Value holding the alignment that has to be performed post allocation
// (in conjunction with allocators that do not support alignment, eg.
// malloc); nullptr if no such adjustment needs to be performed.
Value accessAlignment;
// Byte pointer to the allocated buffer.
Value allocatedBytePtr;
Value allocatedTypePtr =
allocateBuffer(loc, cumulativeSize, op, memRefType, one,
accessAlignment, allocatedBytePtr, rewriter);
int64_t offset;
SmallVector<int64_t, 4> strides;
auto successStrides = getStridesAndOffset(memRefType, strides, offset);
(void)successStrides;
assert(succeeded(successStrides) && "unexpected non-strided memref");
assert(offset != MemRefType::getDynamicStrideOrOffset() &&
"unexpected dynamic offset");
// 0-D memref corner case: they have size 1.
assert(
((memRefType.getRank() == 0 && strides.empty() && sizes.size() == 1) ||
(strides.size() == sizes.size())) &&
"unexpected number of strides");
// Create the MemRef descriptor.
auto memRefDescriptor = createMemRefDescriptor(
loc, rewriter, memRefType, allocatedTypePtr, allocatedBytePtr,
accessAlignment, offset, strides, sizes);
// Return the final value of the descriptor.
rewriter.replaceOp(op, {memRefDescriptor});
}
protected:
/// The minimum alignment to use with aligned_alloc (has to be a power of 2).
uint64_t kMinAlignedAllocAlignment = 16UL;
};
struct AllocOpLowering : public AllocLikeOpLowering<AllocOp> {
explicit AllocOpLowering(LLVMTypeConverter &converter,
const LowerToLLVMOptions &options)
: AllocLikeOpLowering<AllocOp>(converter, options) {}
};
using AllocaOpLowering = AllocLikeOpLowering<AllocaOp>;
/// Copies the shaped descriptor part to (if `toDynamic` is set) or from
/// (otherwise) the dynamically allocated memory for any operands that were
/// unranked descriptors originally.
static LogicalResult copyUnrankedDescriptors(OpBuilder &builder, Location loc,
LLVMTypeConverter &typeConverter,
TypeRange origTypes,
SmallVectorImpl<Value> &operands,
bool toDynamic) {
assert(origTypes.size() == operands.size() &&
"expected as may original types as operands");
// Find operands of unranked memref type and store them.
SmallVector<UnrankedMemRefDescriptor, 4> unrankedMemrefs;
for (unsigned i = 0, e = operands.size(); i < e; ++i)
if (origTypes[i].isa<UnrankedMemRefType>())
unrankedMemrefs.emplace_back(operands[i]);
if (unrankedMemrefs.empty())
return success();
// Compute allocation sizes.
SmallVector<Value, 4> sizes;
UnrankedMemRefDescriptor::computeSizes(builder, loc, typeConverter,
unrankedMemrefs, sizes);
// Get frequently used types.
auto voidType = LLVM::LLVMType::getVoidTy(typeConverter.getDialect());
auto voidPtrType = LLVM::LLVMType::getInt8PtrTy(typeConverter.getDialect());
auto i1Type = LLVM::LLVMType::getInt1Ty(typeConverter.getDialect());
LLVM::LLVMType indexType = typeConverter.getIndexType();
// Find the malloc and free, or declare them if necessary.
auto module = builder.getInsertionPoint()->getParentOfType<ModuleOp>();
auto mallocFunc = module.lookupSymbol<LLVM::LLVMFuncOp>("malloc");
if (!mallocFunc && toDynamic) {
OpBuilder::InsertionGuard guard(builder);
builder.setInsertionPointToStart(module.getBody());
mallocFunc = builder.create<LLVM::LLVMFuncOp>(
builder.getUnknownLoc(), "malloc",
LLVM::LLVMType::getFunctionTy(
voidPtrType, llvm::makeArrayRef(indexType), /*isVarArg=*/false));
}
auto freeFunc = module.lookupSymbol<LLVM::LLVMFuncOp>("free");
if (!freeFunc && !toDynamic) {
OpBuilder::InsertionGuard guard(builder);
builder.setInsertionPointToStart(module.getBody());
freeFunc = builder.create<LLVM::LLVMFuncOp>(
builder.getUnknownLoc(), "free",
LLVM::LLVMType::getFunctionTy(voidType, llvm::makeArrayRef(voidPtrType),
/*isVarArg=*/false));
}
// Initialize shared constants.
Value zero =
builder.create<LLVM::ConstantOp>(loc, i1Type, builder.getBoolAttr(false));
unsigned unrankedMemrefPos = 0;
for (unsigned i = 0, e = operands.size(); i < e; ++i) {
Type type = origTypes[i];
if (!type.isa<UnrankedMemRefType>())
continue;
Value allocationSize = sizes[unrankedMemrefPos++];
UnrankedMemRefDescriptor desc(operands[i]);
// Allocate memory, copy, and free the source if necessary.
Value memory =
toDynamic
? builder.create<LLVM::CallOp>(loc, mallocFunc, allocationSize)
.getResult(0)
: builder.create<LLVM::AllocaOp>(loc, voidPtrType, allocationSize,
/*alignment=*/0);
Value source = desc.memRefDescPtr(builder, loc);
builder.create<LLVM::MemcpyOp>(loc, memory, source, allocationSize, zero);
if (!toDynamic)
builder.create<LLVM::CallOp>(loc, freeFunc, source);
// Create a new descriptor. The same descriptor can be returned multiple
// times, attempting to modify its pointer can lead to memory leaks
// (allocated twice and overwritten) or double frees (the caller does not
// know if the descriptor points to the same memory).
Type descriptorType = typeConverter.convertType(type);
if (!descriptorType)
return failure();
auto updatedDesc =
UnrankedMemRefDescriptor::undef(builder, loc, descriptorType);
Value rank = desc.rank(builder, loc);
updatedDesc.setRank(builder, loc, rank);
updatedDesc.setMemRefDescPtr(builder, loc, memory);
operands[i] = updatedDesc;
}
return success();
}
// A CallOp automatically promotes MemRefType to a sequence of alloca/store and
// passes the pointer to the MemRef across function boundaries.
template <typename CallOpType>
struct CallOpInterfaceLowering : public ConvertOpToLLVMPattern<CallOpType> {
using ConvertOpToLLVMPattern<CallOpType>::ConvertOpToLLVMPattern;
using Super = CallOpInterfaceLowering<CallOpType>;
using Base = ConvertOpToLLVMPattern<CallOpType>;
LogicalResult
matchAndRewrite(Operation *op, ArrayRef<Value> operands,
ConversionPatternRewriter &rewriter) const override {
typename CallOpType::Adaptor transformed(operands);
auto callOp = cast<CallOpType>(op);
// Pack the result types into a struct.
Type packedResult;
unsigned numResults = callOp.getNumResults();
auto resultTypes = llvm::to_vector<4>(callOp.getResultTypes());
if (numResults != 0) {
if (!(packedResult =
this->typeConverter.packFunctionResults(resultTypes)))
return failure();
}
auto promoted = this->typeConverter.promoteMemRefDescriptors(
op->getLoc(), /*opOperands=*/op->getOperands(), operands, rewriter);
auto newOp = rewriter.create<LLVM::CallOp>(op->getLoc(), packedResult,
promoted, op->getAttrs());
SmallVector<Value, 4> results;
if (numResults < 2) {
// If < 2 results, packing did not do anything and we can just return.
results.append(newOp.result_begin(), newOp.result_end());
} else {
// Otherwise, it had been converted to an operation producing a structure.
// Extract individual results from the structure and return them as list.
results.reserve(numResults);
for (unsigned i = 0; i < numResults; ++i) {
auto type = this->typeConverter.convertType(op->getResult(i).getType());
results.push_back(rewriter.create<LLVM::ExtractValueOp>(
op->getLoc(), type, newOp.getOperation()->getResult(0),
rewriter.getI64ArrayAttr(i)));
}
}
if (failed(copyUnrankedDescriptors(
rewriter, op->getLoc(), this->typeConverter, op->getResultTypes(),
results, /*toDynamic=*/false)))
return failure();
rewriter.replaceOp(op, results);
return success();
}
};
struct CallOpLowering : public CallOpInterfaceLowering<CallOp> {
using Super::Super;
};
struct CallIndirectOpLowering : public CallOpInterfaceLowering<CallIndirectOp> {
using Super::Super;
};
// A `dealloc` is converted into a call to `free` on the underlying data buffer.
// The memref descriptor being an SSA value, there is no need to clean it up
// in any way.
struct DeallocOpLowering : public ConvertOpToLLVMPattern<DeallocOp> {
using ConvertOpToLLVMPattern<DeallocOp>::ConvertOpToLLVMPattern;
explicit DeallocOpLowering(LLVMTypeConverter &converter,
const LowerToLLVMOptions &options)
: ConvertOpToLLVMPattern<DeallocOp>(converter, options) {}
LogicalResult
matchAndRewrite(Operation *op, ArrayRef<Value> operands,
ConversionPatternRewriter &rewriter) const override {
assert(operands.size() == 1 && "dealloc takes one operand");
DeallocOp::Adaptor transformed(operands);
// Insert the `free` declaration if it is not already present.
auto freeFunc =
op->getParentOfType<ModuleOp>().lookupSymbol<LLVM::LLVMFuncOp>("free");
if (!freeFunc) {
OpBuilder::InsertionGuard guard(rewriter);
rewriter.setInsertionPointToStart(
op->getParentOfType<ModuleOp>().getBody());
freeFunc = rewriter.create<LLVM::LLVMFuncOp>(
rewriter.getUnknownLoc(), "free",
LLVM::LLVMType::getFunctionTy(getVoidType(), getVoidPtrType(),
/*isVarArg=*/false));
}
MemRefDescriptor memref(transformed.memref());
Value casted = rewriter.create<LLVM::BitcastOp>(
op->getLoc(), getVoidPtrType(),
memref.allocatedPtr(rewriter, op->getLoc()));
rewriter.replaceOpWithNewOp<LLVM::CallOp>(
op, ArrayRef<Type>(), rewriter.getSymbolRefAttr(freeFunc), casted);
return success();
}
};
// A `rsqrt` is converted into `1 / sqrt`.
struct RsqrtOpLowering : public ConvertOpToLLVMPattern<RsqrtOp> {
using ConvertOpToLLVMPattern<RsqrtOp>::ConvertOpToLLVMPattern;
LogicalResult
matchAndRewrite(Operation *op, ArrayRef<Value> operands,
ConversionPatternRewriter &rewriter) const override {
RsqrtOp::Adaptor transformed(operands);
auto operandType =
transformed.operand().getType().dyn_cast<LLVM::LLVMType>();
if (!operandType)
return failure();
auto loc = op->getLoc();
auto resultType = *op->result_type_begin();
auto floatType = getElementTypeOrSelf(resultType).cast<FloatType>();
auto floatOne = rewriter.getFloatAttr(floatType, 1.0);
if (!operandType.isArrayTy()) {
LLVM::ConstantOp one;
if (operandType.isVectorTy()) {
one = rewriter.create<LLVM::ConstantOp>(
loc, operandType,
SplatElementsAttr::get(resultType.cast<ShapedType>(), floatOne));
} else {
one = rewriter.create<LLVM::ConstantOp>(loc, operandType, floatOne);
}
auto sqrt = rewriter.create<LLVM::SqrtOp>(loc, transformed.operand());
rewriter.replaceOpWithNewOp<LLVM::FDivOp>(op, operandType, one, sqrt);
return success();
}
auto vectorType = resultType.dyn_cast<VectorType>();
if (!vectorType)
return failure();
return handleMultidimensionalVectors(
op, operands, typeConverter,
[&](LLVM::LLVMType llvmVectorTy, ValueRange operands) {
auto splatAttr = SplatElementsAttr::get(
mlir::VectorType::get(
{cast<llvm::FixedVectorType>(llvmVectorTy.getUnderlyingType())
->getNumElements()},
floatType),
floatOne);
auto one =
rewriter.create<LLVM::ConstantOp>(loc, llvmVectorTy, splatAttr);
auto sqrt =
rewriter.create<LLVM::SqrtOp>(loc, llvmVectorTy, operands[0]);
return rewriter.create<LLVM::FDivOp>(loc, llvmVectorTy, one, sqrt);
},
rewriter);
}
};
struct MemRefCastOpLowering : public ConvertOpToLLVMPattern<MemRefCastOp> {
using ConvertOpToLLVMPattern<MemRefCastOp>::ConvertOpToLLVMPattern;
LogicalResult match(Operation *op) const override {
auto memRefCastOp = cast<MemRefCastOp>(op);
Type srcType = memRefCastOp.getOperand().getType();
Type dstType = memRefCastOp.getType();
// MemRefCastOp reduce to bitcast in the ranked MemRef case and can be used
// for type erasure. For now they must preserve underlying element type and
// require source and result type to have the same rank. Therefore, perform
// a sanity check that the underlying structs are the same. Once op
// semantics are relaxed we can revisit.
if (srcType.isa<MemRefType>() && dstType.isa<MemRefType>())
return success(typeConverter.convertType(srcType) ==
typeConverter.convertType(dstType));
// At least one of the operands is unranked type
assert(srcType.isa<UnrankedMemRefType>() ||
dstType.isa<UnrankedMemRefType>());
// Unranked to unranked cast is disallowed
return !(srcType.isa<UnrankedMemRefType>() &&
dstType.isa<UnrankedMemRefType>())
? success()
: failure();
}
void rewrite(Operation *op, ArrayRef<Value> operands,
ConversionPatternRewriter &rewriter) const override {
auto memRefCastOp = cast<MemRefCastOp>(op);
MemRefCastOp::Adaptor transformed(operands);
auto srcType = memRefCastOp.getOperand().getType();
auto dstType = memRefCastOp.getType();
auto targetStructType = typeConverter.convertType(memRefCastOp.getType());
auto loc = op->getLoc();
// MemRefCastOp reduce to bitcast in the ranked MemRef case.
if (srcType.isa<MemRefType>() && dstType.isa<MemRefType>()) {
rewriter.replaceOpWithNewOp<LLVM::BitcastOp>(op, targetStructType,
transformed.source());
} else if (srcType.isa<MemRefType>() && dstType.isa<UnrankedMemRefType>()) {
// Casting ranked to unranked memref type
// Set the rank in the destination from the memref type
// Allocate space on the stack and copy the src memref descriptor
// Set the ptr in the destination to the stack space
auto srcMemRefType = srcType.cast<MemRefType>();
int64_t rank = srcMemRefType.getRank();
// ptr = AllocaOp sizeof(MemRefDescriptor)
auto ptr = typeConverter.promoteOneMemRefDescriptor(
loc, transformed.source(), rewriter);
// voidptr = BitCastOp srcType* to void*
auto voidPtr =
rewriter.create<LLVM::BitcastOp>(loc, getVoidPtrType(), ptr)
.getResult();
// rank = ConstantOp srcRank
auto rankVal = rewriter.create<LLVM::ConstantOp>(
loc, typeConverter.convertType(rewriter.getIntegerType(64)),
rewriter.getI64IntegerAttr(rank));
// undef = UndefOp
UnrankedMemRefDescriptor memRefDesc =
UnrankedMemRefDescriptor::undef(rewriter, loc, targetStructType);
// d1 = InsertValueOp undef, rank, 0
memRefDesc.setRank(rewriter, loc, rankVal);
// d2 = InsertValueOp d1, voidptr, 1
memRefDesc.setMemRefDescPtr(rewriter, loc, voidPtr);
rewriter.replaceOp(op, (Value)memRefDesc);
} else if (srcType.isa<UnrankedMemRefType>() && dstType.isa<MemRefType>()) {
// Casting from unranked type to ranked.
// The operation is assumed to be doing a correct cast. If the destination
// type mismatches the unranked the type, it is undefined behavior.
UnrankedMemRefDescriptor memRefDesc(transformed.source());
// ptr = ExtractValueOp src, 1
auto ptr = memRefDesc.memRefDescPtr(rewriter, loc);
// castPtr = BitCastOp i8* to structTy*
auto castPtr =
rewriter
.create<LLVM::BitcastOp>(
loc, targetStructType.cast<LLVM::LLVMType>().getPointerTo(),
ptr)
.getResult();
// struct = LoadOp castPtr
auto loadOp = rewriter.create<LLVM::LoadOp>(loc, castPtr);
rewriter.replaceOp(op, loadOp.getResult());
} else {
llvm_unreachable("Unsupported unranked memref to unranked memref cast");
}
}
};
struct DialectCastOpLowering
: public ConvertOpToLLVMPattern<LLVM::DialectCastOp> {
using ConvertOpToLLVMPattern<LLVM::DialectCastOp>::ConvertOpToLLVMPattern;
LogicalResult
matchAndRewrite(Operation *op, ArrayRef<Value> operands,
ConversionPatternRewriter &rewriter) const override {
auto castOp = cast<LLVM::DialectCastOp>(op);
LLVM::DialectCastOp::Adaptor transformed(operands);
if (transformed.in().getType() !=
typeConverter.convertType(castOp.getType())) {
return failure();
}
rewriter.replaceOp(op, transformed.in());
return success();
}
};
// A `dim` is converted to a constant for static sizes and to an access to the
// size stored in the memref descriptor for dynamic sizes.
struct DimOpLowering : public ConvertOpToLLVMPattern<DimOp> {
using ConvertOpToLLVMPattern<DimOp>::ConvertOpToLLVMPattern;
LogicalResult
matchAndRewrite(Operation *op, ArrayRef<Value> operands,
ConversionPatternRewriter &rewriter) const override {
auto dimOp = cast<DimOp>(op);
auto loc = op->getLoc();
DimOp::Adaptor transformed(operands);
// Take advantage if index is constant.
MemRefType memRefType = dimOp.memrefOrTensor().getType().cast<MemRefType>();
if (Optional<int64_t> index = dimOp.getConstantIndex()) {
int64_t i = index.getValue();
if (memRefType.isDynamicDim(i)) {
// Extract dynamic size from the memref descriptor.
MemRefDescriptor descriptor(transformed.memrefOrTensor());
rewriter.replaceOp(op, {descriptor.size(rewriter, loc, i)});
} else {
// Use constant for static size.
int64_t dimSize = memRefType.getDimSize(i);
rewriter.replaceOp(op, createIndexConstant(rewriter, loc, dimSize));
}
return success();
}
Value index = dimOp.index();
int64_t rank = memRefType.getRank();
MemRefDescriptor memrefDescriptor(transformed.memrefOrTensor());
rewriter.replaceOp(op, {memrefDescriptor.size(rewriter, loc, index, rank)});
return success();
}
};
// Common base for load and store operations on MemRefs. Restricts the match
// to supported MemRef types. Provides functionality to emit code accessing a
// specific element of the underlying data buffer.
template <typename Derived>
struct LoadStoreOpLowering : public ConvertOpToLLVMPattern<Derived> {
using ConvertOpToLLVMPattern<Derived>::ConvertOpToLLVMPattern;
using Base = LoadStoreOpLowering<Derived>;
LogicalResult match(Operation *op) const override {
MemRefType type = cast<Derived>(op).getMemRefType();
return isSupportedMemRefType(type) ? success() : failure();
}
};
// Load operation is lowered to obtaining a pointer to the indexed element
// and loading it.
struct LoadOpLowering : public LoadStoreOpLowering<LoadOp> {
using Base::Base;
LogicalResult
matchAndRewrite(Operation *op, ArrayRef<Value> operands,
ConversionPatternRewriter &rewriter) const override {
auto loadOp = cast<LoadOp>(op);
LoadOp::Adaptor transformed(operands);
auto type = loadOp.getMemRefType();
Value dataPtr = getDataPtr(op->getLoc(), type, transformed.memref(),
transformed.indices(), rewriter, getModule());
rewriter.replaceOpWithNewOp<LLVM::LoadOp>(op, dataPtr);
return success();
}
};
// Store operation is lowered to obtaining a pointer to the indexed element,
// and storing the given value to it.
struct StoreOpLowering : public LoadStoreOpLowering<StoreOp> {
using Base::Base;
LogicalResult
matchAndRewrite(Operation *op, ArrayRef<Value> operands,
ConversionPatternRewriter &rewriter) const override {
auto type = cast<StoreOp>(op).getMemRefType();
StoreOp::Adaptor transformed(operands);
Value dataPtr = getDataPtr(op->getLoc(), type, transformed.memref(),
transformed.indices(), rewriter, getModule());
rewriter.replaceOpWithNewOp<LLVM::StoreOp>(op, transformed.value(),
dataPtr);
return success();
}
};
// The prefetch operation is lowered in a way similar to the load operation
// except that the llvm.prefetch operation is used for replacement.
struct PrefetchOpLowering : public LoadStoreOpLowering<PrefetchOp> {
using Base::Base;
LogicalResult
matchAndRewrite(Operation *op, ArrayRef<Value> operands,
ConversionPatternRewriter &rewriter) const override {
auto prefetchOp = cast<PrefetchOp>(op);
PrefetchOp::Adaptor transformed(operands);
auto type = prefetchOp.getMemRefType();
Value dataPtr = getDataPtr(op->getLoc(), type, transformed.memref(),
transformed.indices(), rewriter, getModule());
// Replace with llvm.prefetch.
auto llvmI32Type = typeConverter.convertType(rewriter.getIntegerType(32));
auto isWrite = rewriter.create<LLVM::ConstantOp>(
op->getLoc(), llvmI32Type,
rewriter.getI32IntegerAttr(prefetchOp.isWrite()));
auto localityHint = rewriter.create<LLVM::ConstantOp>(
op->getLoc(), llvmI32Type,
rewriter.getI32IntegerAttr(prefetchOp.localityHint().getZExtValue()));
auto isData = rewriter.create<LLVM::ConstantOp>(
op->getLoc(), llvmI32Type,
rewriter.getI32IntegerAttr(prefetchOp.isDataCache()));
rewriter.replaceOpWithNewOp<LLVM::Prefetch>(op, dataPtr, isWrite,
localityHint, isData);
return success();
}
};
// The lowering of index_cast becomes an integer conversion since index becomes
// an integer. If the bit width of the source and target integer types is the
// same, just erase the cast. If the target type is wider, sign-extend the
// value, otherwise truncate it.
struct IndexCastOpLowering : public ConvertOpToLLVMPattern<IndexCastOp> {
using ConvertOpToLLVMPattern<IndexCastOp>::ConvertOpToLLVMPattern;
LogicalResult
matchAndRewrite(Operation *op, ArrayRef<Value> operands,
ConversionPatternRewriter &rewriter) const override {
IndexCastOpAdaptor transformed(operands);
auto indexCastOp = cast<IndexCastOp>(op);
auto targetType =
this->typeConverter.convertType(indexCastOp.getResult().getType())
.cast<LLVM::LLVMType>();
auto sourceType = transformed.in().getType().cast<LLVM::LLVMType>();
unsigned targetBits = targetType.getUnderlyingType()->getIntegerBitWidth();
unsigned sourceBits = sourceType.getUnderlyingType()->getIntegerBitWidth();
if (targetBits == sourceBits)
rewriter.replaceOp(op, transformed.in());
else if (targetBits < sourceBits)
rewriter.replaceOpWithNewOp<LLVM::TruncOp>(op, targetType,
transformed.in());
else
rewriter.replaceOpWithNewOp<LLVM::SExtOp>(op, targetType,
transformed.in());
return success();
}
};
// Convert std.cmp predicate into the LLVM dialect CmpPredicate. The two
// enums share the numerical values so just cast.
template <typename LLVMPredType, typename StdPredType>
static LLVMPredType convertCmpPredicate(StdPredType pred) {
return static_cast<LLVMPredType>(pred);
}
struct CmpIOpLowering : public ConvertOpToLLVMPattern<CmpIOp> {
using ConvertOpToLLVMPattern<CmpIOp>::ConvertOpToLLVMPattern;
LogicalResult
matchAndRewrite(Operation *op, ArrayRef<Value> operands,
ConversionPatternRewriter &rewriter) const override {
auto cmpiOp = cast<CmpIOp>(op);
CmpIOpAdaptor transformed(operands);
rewriter.replaceOpWithNewOp<LLVM::ICmpOp>(
op, typeConverter.convertType(cmpiOp.getResult().getType()),
rewriter.getI64IntegerAttr(static_cast<int64_t>(
convertCmpPredicate<LLVM::ICmpPredicate>(cmpiOp.getPredicate()))),
transformed.lhs(), transformed.rhs());
return success();
}
};
struct CmpFOpLowering : public ConvertOpToLLVMPattern<CmpFOp> {
using ConvertOpToLLVMPattern<CmpFOp>::ConvertOpToLLVMPattern;
LogicalResult
matchAndRewrite(Operation *op, ArrayRef<Value> operands,
ConversionPatternRewriter &rewriter) const override {
auto cmpfOp = cast<CmpFOp>(op);
CmpFOpAdaptor transformed(operands);
rewriter.replaceOpWithNewOp<LLVM::FCmpOp>(
op, typeConverter.convertType(cmpfOp.getResult().getType()),
rewriter.getI64IntegerAttr(static_cast<int64_t>(
convertCmpPredicate<LLVM::FCmpPredicate>(cmpfOp.getPredicate()))),
transformed.lhs(), transformed.rhs());
return success();
}
};
struct SIToFPLowering
: public OneToOneConvertToLLVMPattern<SIToFPOp, LLVM::SIToFPOp> {
using Super::Super;
};
struct FPExtLowering
: public OneToOneConvertToLLVMPattern<FPExtOp, LLVM::FPExtOp> {
using Super::Super;
};
struct FPToSILowering
: public OneToOneConvertToLLVMPattern<FPToSIOp, LLVM::FPToSIOp> {
using Super::Super;
};
struct FPTruncLowering
: public OneToOneConvertToLLVMPattern<FPTruncOp, LLVM::FPTruncOp> {
using Super::Super;
};
struct SignExtendIOpLowering
: public OneToOneConvertToLLVMPattern<SignExtendIOp, LLVM::SExtOp> {
using Super::Super;
};
struct TruncateIOpLowering
: public OneToOneConvertToLLVMPattern<TruncateIOp, LLVM::TruncOp> {
using Super::Super;
};
struct ZeroExtendIOpLowering
: public OneToOneConvertToLLVMPattern<ZeroExtendIOp, LLVM::ZExtOp> {
using Super::Super;
};
// Base class for LLVM IR lowering terminator operations with successors.
template <typename SourceOp, typename TargetOp>
struct OneToOneLLVMTerminatorLowering
: public ConvertOpToLLVMPattern<SourceOp> {
using ConvertOpToLLVMPattern<SourceOp>::ConvertOpToLLVMPattern;
using Super = OneToOneLLVMTerminatorLowering<SourceOp, TargetOp>;
LogicalResult
matchAndRewrite(Operation *op, ArrayRef<Value> operands,
ConversionPatternRewriter &rewriter) const override {
rewriter.replaceOpWithNewOp<TargetOp>(op, operands, op->getSuccessors(),
op->getAttrs());
return success();
}
};
// Special lowering pattern for `ReturnOps`. Unlike all other operations,
// `ReturnOp` interacts with the function signature and must have as many
// operands as the function has return values. Because in LLVM IR, functions
// can only return 0 or 1 value, we pack multiple values into a structure type.
// Emit `UndefOp` followed by `InsertValueOp`s to create such structure if
// necessary before returning it
struct ReturnOpLowering : public ConvertOpToLLVMPattern<ReturnOp> {
using ConvertOpToLLVMPattern<ReturnOp>::ConvertOpToLLVMPattern;
LogicalResult
matchAndRewrite(Operation *op, ArrayRef<Value> operands,
ConversionPatternRewriter &rewriter) const override {
unsigned numArguments = op->getNumOperands();
auto updatedOperands = llvm::to_vector<4>(operands);
copyUnrankedDescriptors(rewriter, op->getLoc(), typeConverter,
op->getOperands().getTypes(), updatedOperands,
/*toDynamic=*/true);
// If ReturnOp has 0 or 1 operand, create it and return immediately.
if (numArguments == 0) {
rewriter.replaceOpWithNewOp<LLVM::ReturnOp>(
op, ArrayRef<Type>(), ArrayRef<Value>(), op->getAttrs());
return success();
}
if (numArguments == 1) {
rewriter.replaceOpWithNewOp<LLVM::ReturnOp>(
op, ArrayRef<Type>(), updatedOperands, op->getAttrs());
return success();
}
// Otherwise, we need to pack the arguments into an LLVM struct type before
// returning.
auto packedType = typeConverter.packFunctionResults(
llvm::to_vector<4>(op->getOperandTypes()));
Value packed = rewriter.create<LLVM::UndefOp>(op->getLoc(), packedType);
for (unsigned i = 0; i < numArguments; ++i) {
packed = rewriter.create<LLVM::InsertValueOp>(
op->getLoc(), packedType, packed, updatedOperands[i],
rewriter.getI64ArrayAttr(i));
}
rewriter.replaceOpWithNewOp<LLVM::ReturnOp>(op, ArrayRef<Type>(), packed,
op->getAttrs());
return success();
}
};
// FIXME: this should be tablegen'ed as well.
struct BranchOpLowering
: public OneToOneLLVMTerminatorLowering<BranchOp, LLVM::BrOp> {
using Super::Super;
};
struct CondBranchOpLowering
: public OneToOneLLVMTerminatorLowering<CondBranchOp, LLVM::CondBrOp> {
using Super::Super;
};
// The Splat operation is lowered to an insertelement + a shufflevector
// operation. Splat to only 1-d vector result types are lowered.
struct SplatOpLowering : public ConvertOpToLLVMPattern<SplatOp> {
using ConvertOpToLLVMPattern<SplatOp>::ConvertOpToLLVMPattern;
LogicalResult
matchAndRewrite(Operation *op, ArrayRef<Value> operands,
ConversionPatternRewriter &rewriter) const override {
auto splatOp = cast<SplatOp>(op);
VectorType resultType = splatOp.getType().dyn_cast<VectorType>();
if (!resultType || resultType.getRank() != 1)
return failure();
// First insert it into an undef vector so we can shuffle it.
auto vectorType = typeConverter.convertType(splatOp.getType());
Value undef = rewriter.create<LLVM::UndefOp>(op->getLoc(), vectorType);
auto zero = rewriter.create<LLVM::ConstantOp>(
op->getLoc(), typeConverter.convertType(rewriter.getIntegerType(32)),
rewriter.getZeroAttr(rewriter.getIntegerType(32)));
auto v = rewriter.create<LLVM::InsertElementOp>(
op->getLoc(), vectorType, undef, splatOp.getOperand(), zero);
int64_t width = splatOp.getType().cast<VectorType>().getDimSize(0);
SmallVector<int32_t, 4> zeroValues(width, 0);
// Shuffle the value across the desired number of elements.
ArrayAttr zeroAttrs = rewriter.getI32ArrayAttr(zeroValues);
rewriter.replaceOpWithNewOp<LLVM::ShuffleVectorOp>(op, v, undef, zeroAttrs);
return success();
}
};
// The Splat operation is lowered to an insertelement + a shufflevector
// operation. Splat to only 2+-d vector result types are lowered by the
// SplatNdOpLowering, the 1-d case is handled by SplatOpLowering.
struct SplatNdOpLowering : public ConvertOpToLLVMPattern<SplatOp> {
using ConvertOpToLLVMPattern<SplatOp>::ConvertOpToLLVMPattern;
LogicalResult
matchAndRewrite(Operation *op, ArrayRef<Value> operands,
ConversionPatternRewriter &rewriter) const override {
auto splatOp = cast<SplatOp>(op);
SplatOp::Adaptor adaptor(operands);
VectorType resultType = splatOp.getType().dyn_cast<VectorType>();
if (!resultType || resultType.getRank() == 1)
return failure();
// First insert it into an undef vector so we can shuffle it.
auto loc = op->getLoc();
auto vectorTypeInfo = extractNDVectorTypeInfo(resultType, typeConverter);
auto llvmArrayTy = vectorTypeInfo.llvmArrayTy;
auto llvmVectorTy = vectorTypeInfo.llvmVectorTy;
if (!llvmArrayTy || !llvmVectorTy)
return failure();
// Construct returned value.
Value desc = rewriter.create<LLVM::UndefOp>(loc, llvmArrayTy);
// Construct a 1-D vector with the splatted value that we insert in all the
// places within the returned descriptor.
Value vdesc = rewriter.create<LLVM::UndefOp>(loc, llvmVectorTy);
auto zero = rewriter.create<LLVM::ConstantOp>(
loc, typeConverter.convertType(rewriter.getIntegerType(32)),
rewriter.getZeroAttr(rewriter.getIntegerType(32)));
Value v = rewriter.create<LLVM::InsertElementOp>(loc, llvmVectorTy, vdesc,
adaptor.input(), zero);
// Shuffle the value across the desired number of elements.
int64_t width = resultType.getDimSize(resultType.getRank() - 1);
SmallVector<int32_t, 4> zeroValues(width, 0);
ArrayAttr zeroAttrs = rewriter.getI32ArrayAttr(zeroValues);
v = rewriter.create<LLVM::ShuffleVectorOp>(loc, v, v, zeroAttrs);
// Iterate of linear index, convert to coords space and insert splatted 1-D
// vector in each position.
nDVectorIterate(vectorTypeInfo, rewriter, [&](ArrayAttr position) {
desc = rewriter.create<LLVM::InsertValueOp>(loc, llvmArrayTy, desc, v,
position);
});
rewriter.replaceOp(op, desc);
return success();
}
};
/// Conversion pattern that transforms a subview op into:
/// 1. An `llvm.mlir.undef` operation to create a memref descriptor
/// 2. Updates to the descriptor to introduce the data ptr, offset, size
/// and stride.
/// The subview op is replaced by the descriptor.
struct SubViewOpLowering : public ConvertOpToLLVMPattern<SubViewOp> {
using ConvertOpToLLVMPattern<SubViewOp>::ConvertOpToLLVMPattern;
LogicalResult
matchAndRewrite(Operation *op, ArrayRef<Value> operands,
ConversionPatternRewriter &rewriter) const override {
auto loc = op->getLoc();
auto subViewOp = cast<SubViewOp>(op);
auto sourceMemRefType = subViewOp.source().getType().cast<MemRefType>();
auto sourceElementTy =
typeConverter.convertType(sourceMemRefType.getElementType())
.dyn_cast_or_null<LLVM::LLVMType>();
auto viewMemRefType = subViewOp.getType();
auto targetElementTy =
typeConverter.convertType(viewMemRefType.getElementType())
.dyn_cast<LLVM::LLVMType>();
auto targetDescTy = typeConverter.convertType(viewMemRefType)
.dyn_cast_or_null<LLVM::LLVMType>();
if (!sourceElementTy || !targetDescTy)
return failure();
// Extract the offset and strides from the type.
int64_t offset;
SmallVector<int64_t, 4> strides;
auto successStrides = getStridesAndOffset(viewMemRefType, strides, offset);
if (failed(successStrides))
return failure();
// Create the descriptor.
if (!operands.front().getType().isa<LLVM::LLVMType>())
return failure();
MemRefDescriptor sourceMemRef(operands.front());
auto targetMemRef = MemRefDescriptor::undef(rewriter, loc, targetDescTy);
// Copy the buffer pointer from the old descriptor to the new one.
Value extracted = sourceMemRef.allocatedPtr(rewriter, loc);
Value bitcastPtr = rewriter.create<LLVM::BitcastOp>(
loc, targetElementTy.getPointerTo(viewMemRefType.getMemorySpace()),
extracted);
targetMemRef.setAllocatedPtr(rewriter, loc, bitcastPtr);
// Copy the buffer pointer from the old descriptor to the new one.
extracted = sourceMemRef.alignedPtr(rewriter, loc);
bitcastPtr = rewriter.create<LLVM::BitcastOp>(
loc, targetElementTy.getPointerTo(viewMemRefType.getMemorySpace()),
extracted);
targetMemRef.setAlignedPtr(rewriter, loc, bitcastPtr);
// Extract strides needed to compute offset.
SmallVector<Value, 4> strideValues;
strideValues.reserve(viewMemRefType.getRank());
for (int i = 0, e = viewMemRefType.getRank(); i < e; ++i)
strideValues.push_back(sourceMemRef.stride(rewriter, loc, i));
// Offset.
auto llvmIndexType = typeConverter.convertType(rewriter.getIndexType());
if (!ShapedType::isDynamicStrideOrOffset(offset)) {
targetMemRef.setConstantOffset(rewriter, loc, offset);
} else {
Value baseOffset = sourceMemRef.offset(rewriter, loc);
for (unsigned i = 0, e = viewMemRefType.getRank(); i < e; ++i) {
Value offset =
subViewOp.isDynamicOffset(i)
? operands[subViewOp.getIndexOfDynamicOffset(i)]
: rewriter.create<LLVM::ConstantOp>(
loc, llvmIndexType,
rewriter.getI64IntegerAttr(subViewOp.getStaticOffset(i)));
Value mul = rewriter.create<LLVM::MulOp>(loc, offset, strideValues[i]);
baseOffset = rewriter.create<LLVM::AddOp>(loc, baseOffset, mul);
}
targetMemRef.setOffset(rewriter, loc, baseOffset);
}
// Update sizes and strides.
for (int i = viewMemRefType.getRank() - 1; i >= 0; --i) {
Value size =
subViewOp.isDynamicSize(i)
? operands[subViewOp.getIndexOfDynamicSize(i)]
: rewriter.create<LLVM::ConstantOp>(
loc, llvmIndexType,
rewriter.getI64IntegerAttr(subViewOp.getStaticSize(i)));
targetMemRef.setSize(rewriter, loc, i, size);
Value stride;
if (!ShapedType::isDynamicStrideOrOffset(strides[i])) {
stride = rewriter.create<LLVM::ConstantOp>(
loc, llvmIndexType, rewriter.getI64IntegerAttr(strides[i]));
} else {
stride =
subViewOp.isDynamicStride(i)
? operands[subViewOp.getIndexOfDynamicStride(i)]
: rewriter.create<LLVM::ConstantOp>(
loc, llvmIndexType,
rewriter.getI64IntegerAttr(subViewOp.getStaticStride(i)));
stride = rewriter.create<LLVM::MulOp>(loc, stride, strideValues[i]);
}
targetMemRef.setStride(rewriter, loc, i, stride);
}
rewriter.replaceOp(op, {targetMemRef});
return success();
}
};
/// Conversion pattern that transforms an op into:
/// 1. An `llvm.mlir.undef` operation to create a memref descriptor
/// 2. Updates to the descriptor to introduce the data ptr, offset, size
/// and stride.
/// The view op is replaced by the descriptor.
struct ViewOpLowering : public ConvertOpToLLVMPattern<ViewOp> {
using ConvertOpToLLVMPattern<ViewOp>::ConvertOpToLLVMPattern;
// Build and return the value for the idx^th shape dimension, either by
// returning the constant shape dimension or counting the proper dynamic size.
Value getSize(ConversionPatternRewriter &rewriter, Location loc,
ArrayRef<int64_t> shape, ValueRange dynamicSizes,
unsigned idx) const {
assert(idx < shape.size());
if (!ShapedType::isDynamic(shape[idx]))
return createIndexConstant(rewriter, loc, shape[idx]);
// Count the number of dynamic dims in range [0, idx]
unsigned nDynamic = llvm::count_if(shape.take_front(idx), [](int64_t v) {
return ShapedType::isDynamic(v);
});
return dynamicSizes[nDynamic];
}
// Build and return the idx^th stride, either by returning the constant stride
// or by computing the dynamic stride from the current `runningStride` and
// `nextSize`. The caller should keep a running stride and update it with the
// result returned by this function.
Value getStride(ConversionPatternRewriter &rewriter, Location loc,
ArrayRef<int64_t> strides, Value nextSize,
Value runningStride, unsigned idx) const {
assert(idx < strides.size());
if (strides[idx] != MemRefType::getDynamicStrideOrOffset())
return createIndexConstant(rewriter, loc, strides[idx]);
if (nextSize)
return runningStride
? rewriter.create<LLVM::MulOp>(loc, runningStride, nextSize)
: nextSize;
assert(!runningStride);
return createIndexConstant(rewriter, loc, 1);
}
LogicalResult
matchAndRewrite(Operation *op, ArrayRef<Value> operands,
ConversionPatternRewriter &rewriter) const override {
auto loc = op->getLoc();
auto viewOp = cast<ViewOp>(op);
ViewOpAdaptor adaptor(operands);
auto viewMemRefType = viewOp.getType();
auto targetElementTy =
typeConverter.convertType(viewMemRefType.getElementType())
.dyn_cast<LLVM::LLVMType>();
auto targetDescTy =
typeConverter.convertType(viewMemRefType).dyn_cast<LLVM::LLVMType>();
if (!targetDescTy)
return op->emitWarning("Target descriptor type not converted to LLVM"),
failure();
int64_t offset;
SmallVector<int64_t, 4> strides;
auto successStrides = getStridesAndOffset(viewMemRefType, strides, offset);
if (failed(successStrides))
return op->emitWarning("cannot cast to non-strided shape"), failure();
assert(offset == 0 && "expected offset to be 0");
// Create the descriptor.
MemRefDescriptor sourceMemRef(adaptor.source());
auto targetMemRef = MemRefDescriptor::undef(rewriter, loc, targetDescTy);
// Field 1: Copy the allocated pointer, used for malloc/free.
Value allocatedPtr = sourceMemRef.allocatedPtr(rewriter, loc);
Value bitcastPtr = rewriter.create<LLVM::BitcastOp>(
loc, targetElementTy.getPointerTo(), allocatedPtr);
targetMemRef.setAllocatedPtr(rewriter, loc, bitcastPtr);
// Field 2: Copy the actual aligned pointer to payload.
Value alignedPtr = sourceMemRef.alignedPtr(rewriter, loc);
alignedPtr = rewriter.create<LLVM::GEPOp>(loc, alignedPtr.getType(),
alignedPtr, adaptor.byte_shift());
bitcastPtr = rewriter.create<LLVM::BitcastOp>(
loc, targetElementTy.getPointerTo(), alignedPtr);
targetMemRef.setAlignedPtr(rewriter, loc, bitcastPtr);
// Field 3: The offset in the resulting type must be 0. This is because of
// the type change: an offset on srcType* may not be expressible as an
// offset on dstType*.
targetMemRef.setOffset(rewriter, loc,
createIndexConstant(rewriter, loc, offset));
// Early exit for 0-D corner case.
if (viewMemRefType.getRank() == 0)
return rewriter.replaceOp(op, {targetMemRef}), success();
// Fields 4 and 5: Update sizes and strides.
if (strides.back() != 1)
return op->emitWarning("cannot cast to non-contiguous shape"), failure();
Value stride = nullptr, nextSize = nullptr;
for (int i = viewMemRefType.getRank() - 1; i >= 0; --i) {
// Update size.
Value size =
getSize(rewriter, loc, viewMemRefType.getShape(), adaptor.sizes(), i);
targetMemRef.setSize(rewriter, loc, i, size);
// Update stride.
stride = getStride(rewriter, loc, strides, nextSize, stride, i);
targetMemRef.setStride(rewriter, loc, i, stride);
nextSize = size;
}
rewriter.replaceOp(op, {targetMemRef});
return success();
}
};
struct AssumeAlignmentOpLowering
: public ConvertOpToLLVMPattern<AssumeAlignmentOp> {
using ConvertOpToLLVMPattern<AssumeAlignmentOp>::ConvertOpToLLVMPattern;
LogicalResult
matchAndRewrite(Operation *op, ArrayRef<Value> operands,
ConversionPatternRewriter &rewriter) const override {
AssumeAlignmentOp::Adaptor transformed(operands);
Value memref = transformed.memref();
unsigned alignment = cast<AssumeAlignmentOp>(op).alignment().getZExtValue();
MemRefDescriptor memRefDescriptor(memref);
Value ptr = memRefDescriptor.alignedPtr(rewriter, memref.getLoc());
// Emit llvm.assume(memref.alignedPtr & (alignment - 1) == 0). Notice that
// the asserted memref.alignedPtr isn't used anywhere else, as the real
// users like load/store/views always re-extract memref.alignedPtr as they
// get lowered.
//
// This relies on LLVM's CSE optimization (potentially after SROA), since
// after CSE all memref.alignedPtr instances get de-duplicated into the same
// pointer SSA value.
Value zero =
createIndexAttrConstant(rewriter, op->getLoc(), getIndexType(), 0);
Value mask = createIndexAttrConstant(rewriter, op->getLoc(), getIndexType(),
alignment - 1);
Value ptrValue =
rewriter.create<LLVM::PtrToIntOp>(op->getLoc(), getIndexType(), ptr);
rewriter.create<LLVM::AssumeOp>(
op->getLoc(),
rewriter.create<LLVM::ICmpOp>(
op->getLoc(), LLVM::ICmpPredicate::eq,
rewriter.create<LLVM::AndOp>(op->getLoc(), ptrValue, mask), zero));
rewriter.eraseOp(op);
return success();
}
};
} // namespace
/// Try to match the kind of a std.atomic_rmw to determine whether to use a
/// lowering to llvm.atomicrmw or fallback to llvm.cmpxchg.
static Optional<LLVM::AtomicBinOp> matchSimpleAtomicOp(AtomicRMWOp atomicOp) {
switch (atomicOp.kind()) {
case AtomicRMWKind::addf:
return LLVM::AtomicBinOp::fadd;
case AtomicRMWKind::addi:
return LLVM::AtomicBinOp::add;
case AtomicRMWKind::assign:
return LLVM::AtomicBinOp::xchg;
case AtomicRMWKind::maxs:
return LLVM::AtomicBinOp::max;
case AtomicRMWKind::maxu:
return LLVM::AtomicBinOp::umax;
case AtomicRMWKind::mins:
return LLVM::AtomicBinOp::min;
case AtomicRMWKind::minu:
return LLVM::AtomicBinOp::umin;
default:
return llvm::None;
}
llvm_unreachable("Invalid AtomicRMWKind");
}
namespace {
struct AtomicRMWOpLowering : public LoadStoreOpLowering<AtomicRMWOp> {
using Base::Base;
LogicalResult
matchAndRewrite(Operation *op, ArrayRef<Value> operands,
ConversionPatternRewriter &rewriter) const override {
auto atomicOp = cast<AtomicRMWOp>(op);
auto maybeKind = matchSimpleAtomicOp(atomicOp);
if (!maybeKind)
return failure();
AtomicRMWOp::Adaptor adaptor(operands);
auto resultType = adaptor.value().getType();
auto memRefType = atomicOp.getMemRefType();
auto dataPtr = getDataPtr(op->getLoc(), memRefType, adaptor.memref(),
adaptor.indices(), rewriter, getModule());
rewriter.replaceOpWithNewOp<LLVM::AtomicRMWOp>(
op, resultType, *maybeKind, dataPtr, adaptor.value(),
LLVM::AtomicOrdering::acq_rel);
return success();
}
};
/// Wrap a llvm.cmpxchg operation in a while loop so that the operation can be
/// retried until it succeeds in atomically storing a new value into memory.
///
/// +---------------------------------+
/// | <code before the AtomicRMWOp> |
/// | <compute initial %loaded> |
/// | br loop(%loaded) |
/// +---------------------------------+
/// |
/// -------| |
/// | v v
/// | +--------------------------------+
/// | | loop(%loaded): |
/// | | <body contents> |
/// | | %pair = cmpxchg |
/// | | %ok = %pair[0] |
/// | | %new = %pair[1] |
/// | | cond_br %ok, end, loop(%new) |
/// | +--------------------------------+
/// | | |
/// |----------- |
/// v
/// +--------------------------------+
/// | end: |
/// | <code after the AtomicRMWOp> |
/// +--------------------------------+
///
struct GenericAtomicRMWOpLowering
: public LoadStoreOpLowering<GenericAtomicRMWOp> {
using Base::Base;
LogicalResult
matchAndRewrite(Operation *op, ArrayRef<Value> operands,
ConversionPatternRewriter &rewriter) const override {
auto atomicOp = cast<GenericAtomicRMWOp>(op);
auto loc = op->getLoc();
GenericAtomicRMWOp::Adaptor adaptor(operands);
LLVM::LLVMType valueType =
typeConverter.convertType(atomicOp.getResult().getType())
.cast<LLVM::LLVMType>();
// Split the block into initial, loop, and ending parts.
auto *initBlock = rewriter.getInsertionBlock();
auto *loopBlock =
rewriter.createBlock(initBlock->getParent(),
std::next(Region::iterator(initBlock)), valueType);
auto *endBlock = rewriter.createBlock(
loopBlock->getParent(), std::next(Region::iterator(loopBlock)));
// Operations range to be moved to `endBlock`.
auto opsToMoveStart = atomicOp.getOperation()->getIterator();
auto opsToMoveEnd = initBlock->back().getIterator();
// Compute the loaded value and branch to the loop block.
rewriter.setInsertionPointToEnd(initBlock);
auto memRefType = atomicOp.memref().getType().cast<MemRefType>();
auto dataPtr = getDataPtr(loc, memRefType, adaptor.memref(),
adaptor.indices(), rewriter, getModule());
Value init = rewriter.create<LLVM::LoadOp>(loc, dataPtr);
rewriter.create<LLVM::BrOp>(loc, init, loopBlock);
// Prepare the body of the loop block.
rewriter.setInsertionPointToStart(loopBlock);
// Clone the GenericAtomicRMWOp region and extract the result.
auto loopArgument = loopBlock->getArgument(0);
BlockAndValueMapping mapping;
mapping.map(atomicOp.getCurrentValue(), loopArgument);
Block &entryBlock = atomicOp.body().front();
for (auto &nestedOp : entryBlock.without_terminator()) {
Operation *clone = rewriter.clone(nestedOp, mapping);
mapping.map(nestedOp.getResults(), clone->getResults());
}
Value result = mapping.lookup(entryBlock.getTerminator()->getOperand(0));
// Prepare the epilog of the loop block.
// Append the cmpxchg op to the end of the loop block.
auto successOrdering = LLVM::AtomicOrdering::acq_rel;
auto failureOrdering = LLVM::AtomicOrdering::monotonic;
auto boolType = LLVM::LLVMType::getInt1Ty(&getDialect());
auto pairType = LLVM::LLVMType::getStructTy(valueType, boolType);
auto cmpxchg = rewriter.create<LLVM::AtomicCmpXchgOp>(
loc, pairType, dataPtr, loopArgument, result, successOrdering,
failureOrdering);
// Extract the %new_loaded and %ok values from the pair.
Value newLoaded = rewriter.create<LLVM::ExtractValueOp>(
loc, valueType, cmpxchg, rewriter.getI64ArrayAttr({0}));
Value ok = rewriter.create<LLVM::ExtractValueOp>(
loc, boolType, cmpxchg, rewriter.getI64ArrayAttr({1}));
// Conditionally branch to the end or back to the loop depending on %ok.
rewriter.create<LLVM::CondBrOp>(loc, ok, endBlock, ArrayRef<Value>(),
loopBlock, newLoaded);
rewriter.setInsertionPointToEnd(endBlock);
MoveOpsRange(atomicOp.getResult(), newLoaded, std::next(opsToMoveStart),
std::next(opsToMoveEnd), rewriter);
// The 'result' of the atomic_rmw op is the newly loaded value.
rewriter.replaceOp(op, {newLoaded});
return success();
}
private:
// Clones a segment of ops [start, end) and erases the original.
void MoveOpsRange(ValueRange oldResult, ValueRange newResult,
Block::iterator start, Block::iterator end,
ConversionPatternRewriter &rewriter) const {
BlockAndValueMapping mapping;
mapping.map(oldResult, newResult);
SmallVector<Operation *, 2> opsToErase;
for (auto it = start; it != end; ++it) {
rewriter.clone(*it, mapping);
opsToErase.push_back(&*it);
}
for (auto *it : opsToErase)
rewriter.eraseOp(it);
}
};
} // namespace
/// Collect a set of patterns to convert from the Standard dialect to LLVM.
void mlir::populateStdToLLVMNonMemoryConversionPatterns(
LLVMTypeConverter &converter, OwningRewritePatternList &patterns,
const LowerToLLVMOptions &options) {
// FIXME: this should be tablegen'ed
// clang-format off
patterns.insert<
AbsFOpLowering,
AddCFOpLowering,
AddFOpLowering,
AddIOpLowering,
AllocaOpLowering,
AndOpLowering,
AtomicRMWOpLowering,
BranchOpLowering,
CallIndirectOpLowering,
CallOpLowering,
CeilFOpLowering,
CmpFOpLowering,
CmpIOpLowering,
CondBranchOpLowering,
CopySignOpLowering,
CosOpLowering,
ConstantOpLowering,
CreateComplexOpLowering,
DialectCastOpLowering,
DivFOpLowering,
ExpOpLowering,
Exp2OpLowering,
GenericAtomicRMWOpLowering,
LogOpLowering,
Log10OpLowering,
Log2OpLowering,
FPExtLowering,
FPToSILowering,
FPTruncLowering,
ImOpLowering,
IndexCastOpLowering,
MulFOpLowering,
MulIOpLowering,
NegFOpLowering,
OrOpLowering,
PrefetchOpLowering,
ReOpLowering,
RemFOpLowering,
ReturnOpLowering,
RsqrtOpLowering,
SIToFPLowering,
SelectOpLowering,
ShiftLeftOpLowering,
SignExtendIOpLowering,
SignedDivIOpLowering,
SignedRemIOpLowering,
SignedShiftRightOpLowering,
SinOpLowering,
SplatOpLowering,
SplatNdOpLowering,
SqrtOpLowering,
SubCFOpLowering,
SubFOpLowering,
SubIOpLowering,
TruncateIOpLowering,
UnsignedDivIOpLowering,
UnsignedRemIOpLowering,
UnsignedShiftRightOpLowering,
XOrOpLowering,
ZeroExtendIOpLowering>(converter, options);
// clang-format on
}
void mlir::populateStdToLLVMMemoryConversionPatterns(
LLVMTypeConverter &converter, OwningRewritePatternList &patterns,
const LowerToLLVMOptions &options) {
// clang-format off
patterns.insert<
AssumeAlignmentOpLowering,
DeallocOpLowering,
DimOpLowering,
LoadOpLowering,
MemRefCastOpLowering,
StoreOpLowering,
SubViewOpLowering,
ViewOpLowering,
AllocOpLowering>(converter, options);
// clang-format on
}
void mlir::populateStdToLLVMFuncOpConversionPattern(
LLVMTypeConverter &converter, OwningRewritePatternList &patterns,
const LowerToLLVMOptions &options) {
if (options.useBarePtrCallConv)
patterns.insert<BarePtrFuncOpConversion>(converter, options);
else
patterns.insert<FuncOpConversion>(converter, options);
}
void mlir::populateStdToLLVMConversionPatterns(
LLVMTypeConverter &converter, OwningRewritePatternList &patterns,
const LowerToLLVMOptions &options) {
populateStdToLLVMFuncOpConversionPattern(converter, patterns, options);
populateStdToLLVMNonMemoryConversionPatterns(converter, patterns, options);
populateStdToLLVMMemoryConversionPatterns(converter, patterns, options);
}
// Create an LLVM IR structure type if there is more than one result.
Type LLVMTypeConverter::packFunctionResults(ArrayRef<Type> types) {
assert(!types.empty() && "expected non-empty list of type");
if (types.size() == 1)
return convertType(types.front());
SmallVector<LLVM::LLVMType, 8> resultTypes;
resultTypes.reserve(types.size());
for (auto t : types) {
auto converted = convertType(t).dyn_cast<LLVM::LLVMType>();
if (!converted)
return {};
resultTypes.push_back(converted);
}
return LLVM::LLVMType::getStructTy(llvmDialect, resultTypes);
}
Value LLVMTypeConverter::promoteOneMemRefDescriptor(Location loc, Value operand,
OpBuilder &builder) {
auto *context = builder.getContext();
auto int64Ty = LLVM::LLVMType::getInt64Ty(getDialect());
auto indexType = IndexType::get(context);
// Alloca with proper alignment. We do not expect optimizations of this
// alloca op and so we omit allocating at the entry block.
auto ptrType = operand.getType().cast<LLVM::LLVMType>().getPointerTo();
Value one = builder.create<LLVM::ConstantOp>(loc, int64Ty,
IntegerAttr::get(indexType, 1));
Value allocated =
builder.create<LLVM::AllocaOp>(loc, ptrType, one, /*alignment=*/0);
// Store into the alloca'ed descriptor.
builder.create<LLVM::StoreOp>(loc, operand, allocated);
return allocated;
}
SmallVector<Value, 4>
LLVMTypeConverter::promoteMemRefDescriptors(Location loc, ValueRange opOperands,
ValueRange operands,
OpBuilder &builder) {
SmallVector<Value, 4> promotedOperands;
promotedOperands.reserve(operands.size());
for (auto it : llvm::zip(opOperands, operands)) {
auto operand = std::get<0>(it);
auto llvmOperand = std::get<1>(it);
if (operand.getType().isa<UnrankedMemRefType>()) {
UnrankedMemRefDescriptor::unpack(builder, loc, llvmOperand,
promotedOperands);
continue;
}
if (auto memrefType = operand.getType().dyn_cast<MemRefType>()) {
MemRefDescriptor::unpack(builder, loc, llvmOperand,
operand.getType().cast<MemRefType>(),
promotedOperands);
continue;
}
promotedOperands.push_back(operand);
}
return promotedOperands;
}
namespace {
/// A pass converting MLIR operations into the LLVM IR dialect.
struct LLVMLoweringPass : public ConvertStandardToLLVMBase<LLVMLoweringPass> {
LLVMLoweringPass() = default;
LLVMLoweringPass(bool useBarePtrCallConv, bool emitCWrappers,
unsigned indexBitwidth, bool useAlignedAlloc) {
this->useBarePtrCallConv = useBarePtrCallConv;
this->emitCWrappers = emitCWrappers;
this->indexBitwidth = indexBitwidth;
this->useAlignedAlloc = useAlignedAlloc;
}
/// Run the dialect converter on the module.
void runOnOperation() override {
if (useBarePtrCallConv && emitCWrappers) {
getOperation().emitError()
<< "incompatible conversion options: bare-pointer calling convention "
"and C wrapper emission";
signalPassFailure();
return;
}
ModuleOp m = getOperation();
LowerToLLVMOptions options = {useBarePtrCallConv, emitCWrappers,
indexBitwidth, useAlignedAlloc};
LLVMTypeConverter typeConverter(&getContext(), options);
OwningRewritePatternList patterns;
populateStdToLLVMConversionPatterns(typeConverter, patterns, options);
LLVMConversionTarget target(getContext());
if (failed(applyPartialConversion(m, target, patterns)))
signalPassFailure();
}
};
} // end namespace
mlir::LLVMConversionTarget::LLVMConversionTarget(MLIRContext &ctx)
: ConversionTarget(ctx) {
this->addLegalDialect<LLVM::LLVMDialect>();
this->addIllegalOp<LLVM::DialectCastOp>();
this->addIllegalOp<TanhOp>();
}
std::unique_ptr<OperationPass<ModuleOp>>
mlir::createLowerToLLVMPass(const LowerToLLVMOptions &options) {
return std::make_unique<LLVMLoweringPass>(
options.useBarePtrCallConv, options.emitCWrappers, options.indexBitwidth,
options.useAlignedAlloc);
}