Add transformation of the NVVM dialect to an LLVM module. Only handles

the generation of intrinsics out of NVVM index ops for now.

--

PiperOrigin-RevId: 245933152
This commit is contained in:
Stephan Herhut 2019-04-30 06:08:21 -07:00 committed by Mehdi Amini
parent 041e961802
commit 5d7231d812
11 changed files with 722 additions and 458 deletions

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@ -0,0 +1,98 @@
//===- ModuleTranslation.h - MLIR to LLVM conversion ------------*- C++ -*-===//
//
// Copyright 2019 The MLIR Authors.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
// =============================================================================
//
// This file implements the translation between an MLIR LLVM dialect module and
// the corresponding LLVMIR module. It only handles core LLVM IR operations.
//
//===----------------------------------------------------------------------===//
#ifndef MLIR_TARGET_LLVMIR_MODULETRANSLATION_H
#define MLIR_TARGET_LLVMIR_MODULETRANSLATION_H
#include "mlir/IR/Block.h"
#include "mlir/IR/Function.h"
#include "mlir/IR/Value.h"
#include "llvm/IR/BasicBlock.h"
#include "llvm/IR/Function.h"
#include "llvm/IR/IRBuilder.h"
#include "llvm/IR/Value.h"
namespace mlir {
class Attribute;
class Location;
class Module;
class Operation;
namespace LLVM {
// Implementation class for module translation. Holds a reference to the module
// being translated, and the mappings between the original and the translated
// functions, basic blocks and values. It is practically easier to hold these
// mappings in one class since the conversion of control flow operations
// needs to look up block and function mappings.
class ModuleTranslation {
public:
template <typename T = ModuleTranslation>
static std::unique_ptr<llvm::Module> translateModule(Module &m) {
auto llvmModule = prepareLLVMModule(m);
T translator(m);
translator.llvmModule = std::move(llvmModule);
if (translator.convertFunctions())
return nullptr;
return std::move(translator.llvmModule);
}
protected:
// Translate the given MLIR module expressed in MLIR LLVM IR dialect into an
// LLVM IR module. The MLIR LLVM IR dialect holds a pointer to an
// LLVMContext, the LLVM IR module will be created in that context.
explicit ModuleTranslation(Module &module) : mlirModule(module) {}
virtual ~ModuleTranslation() {}
virtual bool convertOperation(Operation &op, llvm::IRBuilder<> &builder);
static std::unique_ptr<llvm::Module> prepareLLVMModule(Module &m);
private:
bool convertFunctions();
bool convertOneFunction(Function &func);
void connectPHINodes(Function &func);
bool convertBlock(Block &bb, bool ignoreArguments);
template <typename Range>
SmallVector<llvm::Value *, 8> lookupValues(Range &&values);
llvm::Constant *getLLVMConstant(llvm::Type *llvmType, Attribute attr,
Location loc);
// Original and translated module.
Module &mlirModule;
std::unique_ptr<llvm::Module> llvmModule;
// Mappings between original and translated values, used for lookups.
llvm::DenseMap<Function *, llvm::Function *> functionMapping;
llvm::DenseMap<Value *, llvm::Value *> valueMapping;
llvm::DenseMap<Block *, llvm::BasicBlock *> blockMapping;
};
} // namespace LLVM
} // namespace mlir
#endif // MLIR_TARGET_LLVMIR_MODULETRANSLATION_H

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//===- NVVMIR.h - MLIR to LLVM + NVVM IR conversion -------------*- C++ -*-===//
//
// Copyright 2019 The MLIR Authors.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
// =============================================================================
//
// This file declares the entry point for the MLIR to LLVM + NVVM IR conversion.
//
//===----------------------------------------------------------------------===//
#ifndef MLIR_TARGET_NVVMIR_H
#define MLIR_TARGET_NVVMIR_H
#include <memory>
// Forward-declare LLVM classses.
namespace llvm {
class Module;
} // namespace llvm
namespace mlir {
class Module;
/// Convert the given MLIR module into NVVM IR. This conversion requires the
/// registration of the LLVM IR dialect and will extract the LLVM context
/// from the registered LLVM IR dialect. In case of error, report it
/// to the error handler registered with the MLIR context, if any (obtained from
/// the MLIR module), and return `nullptr`.
std::unique_ptr<llvm::Module> translateModuleToNVVMIR(Module &m);
} // namespace mlir
#endif // MLIR_TARGET_NVVMIR_H

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@ -1 +1,25 @@
add_subdirectory(LLVMIR)
add_llvm_library(MLIRTargetLLVMIRModuleTranslation
LLVMIR/ModuleTranslation.cpp
ADDITIONAL_HEADER_DIRS
${MLIR_MAIN_INCLUDE_DIR}/mlir/Target/LLVMIR
DEPENDS
intrinsics_gen
)
target_link_libraries(MLIRTargetLLVMIRModuleTranslation MLIRLLVMIR LLVMCore LLVMSupport LLVMTransformUtils MLIRTranslation)
add_llvm_library(MLIRTargetLLVMIR
LLVMIR/ConvertToLLVMIR.cpp
ADDITIONAL_HEADER_DIRS
${MLIR_MAIN_INCLUDE_DIR}/mlir/Target/LLVMIR
)
target_link_libraries(MLIRTargetLLVMIR MLIRTargetLLVMIRModuleTranslation)
add_llvm_library(MLIRTargetNVVMIR
LLVMIR/ConvertToNVVMIR.cpp
ADDITIONAL_HEADER_DIRS
${MLIR_MAIN_INCLUDE_DIR}/mlir/Target/LLVMIR
DEPENDS
intrinsics_gen
)
target_link_libraries(MLIRTargetNVVMIR MLIRNVVMIR MLIRTargetLLVMIRModuleTranslation)

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@ -1,9 +0,0 @@
add_llvm_library(MLIRTargetLLVMIR
ConvertToLLVMIR.cpp
ADDITIONAL_HEADER_DIRS
${MLIR_MAIN_INCLUDE_DIR}/mlir/Target/LLVMIR
DEPENDS
intrinsics_gen
)
target_link_libraries(MLIRTargetLLVMIR MLIRLLVMIR MLIRTranslation LLVMCore LLVMSupport LLVMTransformUtils)

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@ -19,461 +19,20 @@
//
//===----------------------------------------------------------------------===//
#include "mlir/IR/Attributes.h"
#include "mlir/IR/Module.h"
#include "mlir/LLVMIR/LLVMDialect.h"
#include "mlir/StandardOps/Ops.h"
#include "mlir/Support/FileUtilities.h"
#include "mlir/Support/LLVM.h"
#include "mlir/Target/LLVMIR.h"
#include "mlir/Support/FileUtilities.h"
#include "mlir/Target/LLVMIR/ModuleTranslation.h"
#include "mlir/Translation.h"
#include "llvm/ADT/SetVector.h"
#include "llvm/IR/BasicBlock.h"
#include "llvm/IR/Constants.h"
#include "llvm/IR/DerivedTypes.h"
#include "llvm/IR/IRBuilder.h"
#include "llvm/IR/LLVMContext.h"
#include "llvm/ADT/StringRef.h"
#include "llvm/IR/Module.h"
#include "llvm/Support/ToolOutputFile.h"
#include "llvm/Transforms/Utils/Cloning.h"
using namespace mlir;
namespace {
// Implementation class for module translation. Holds a reference to the module
// being translated, and the mappings between the original and the translated
// functions, basic blocks and values. It is practically easier to hold these
// mappings in one class since the conversion of control flow operations
// needs to look up block and function mappings.
class ModuleTranslation {
public:
// Translate the given MLIR module expressed in MLIR LLVM IR dialect into an
// LLVM IR module. The MLIR LLVM IR dialect holds a pointer to an
// LLVMContext, the LLVM IR module will be created in that context.
static std::unique_ptr<llvm::Module> translateModule(Module &m);
private:
explicit ModuleTranslation(Module &module) : mlirModule(module) {}
bool convertFunctions();
bool convertOneFunction(Function &func);
void connectPHINodes(Function &func);
bool convertBlock(Block &bb, bool ignoreArguments);
bool convertOperation(Operation &op, llvm::IRBuilder<> &builder);
template <typename Range>
SmallVector<llvm::Value *, 8> lookupValues(Range &&values);
llvm::Constant *getLLVMConstant(llvm::Type *llvmType, Attribute attr,
Location loc);
// Original and translated module.
Module &mlirModule;
std::unique_ptr<llvm::Module> llvmModule;
// Mappings between original and translated values, used for lookups.
llvm::DenseMap<Function *, llvm::Function *> functionMapping;
llvm::DenseMap<Value *, llvm::Value *> valueMapping;
llvm::DenseMap<Block *, llvm::BasicBlock *> blockMapping;
};
} // end anonymous namespace
// Convert an MLIR function type to LLVM IR. Arguments of the function must of
// MLIR LLVM IR dialect types. Use `loc` as a location when reporting errors.
// Return nullptr on errors.
static llvm::FunctionType *convertFunctionType(llvm::LLVMContext &llvmContext,
FunctionType type, Location loc,
bool isVarArgs) {
assert(type && "expected non-null type");
auto context = type.getContext();
if (type.getNumResults() > 1)
return context->emitError(loc,
"LLVM functions can only have 0 or 1 result"),
nullptr;
SmallVector<llvm::Type *, 8> argTypes;
argTypes.reserve(type.getNumInputs());
for (auto t : type.getInputs()) {
auto wrappedLLVMType = t.dyn_cast<LLVM::LLVMType>();
if (!wrappedLLVMType)
return context->emitError(loc, "non-LLVM function argument type"),
nullptr;
argTypes.push_back(wrappedLLVMType.getUnderlyingType());
}
if (type.getNumResults() == 0)
return llvm::FunctionType::get(llvm::Type::getVoidTy(llvmContext), argTypes,
isVarArgs);
auto wrappedResultType = type.getResult(0).dyn_cast<LLVM::LLVMType>();
if (!wrappedResultType)
return context->emitError(loc, "non-LLVM function result"), nullptr;
return llvm::FunctionType::get(wrappedResultType.getUnderlyingType(),
argTypes, isVarArgs);
}
// Create an LLVM IR constant of `llvmType` from the MLIR attribute `attr`.
// This currently supports integer, floating point, splat and dense element
// attributes and combinations thereof. In case of error, report it to `loc`
// and return nullptr.
llvm::Constant *ModuleTranslation::getLLVMConstant(llvm::Type *llvmType,
Attribute attr,
Location loc) {
if (auto intAttr = attr.dyn_cast<IntegerAttr>())
return llvm::ConstantInt::get(llvmType, intAttr.getValue());
if (auto floatAttr = attr.dyn_cast<FloatAttr>())
return llvm::ConstantFP::get(llvmType, floatAttr.getValue());
if (auto funcAttr = attr.dyn_cast<FunctionAttr>())
return functionMapping.lookup(funcAttr.getValue());
if (auto splatAttr = attr.dyn_cast<SplatElementsAttr>()) {
auto *vectorType = cast<llvm::VectorType>(llvmType);
auto *child = getLLVMConstant(vectorType->getElementType(),
splatAttr.getValue(), loc);
return llvm::ConstantVector::getSplat(vectorType->getNumElements(), child);
}
if (auto denseAttr = attr.dyn_cast<DenseElementsAttr>()) {
auto *vectorType = cast<llvm::VectorType>(llvmType);
SmallVector<llvm::Constant *, 8> constants;
uint64_t numElements = vectorType->getNumElements();
constants.reserve(numElements);
SmallVector<Attribute, 8> nested;
denseAttr.getValues(nested);
for (auto n : nested) {
constants.push_back(
getLLVMConstant(vectorType->getElementType(), n, loc));
if (!constants.back())
return nullptr;
}
return llvm::ConstantVector::get(constants);
}
mlirModule.getContext()->emitError(loc, "unsupported constant value");
return nullptr;
}
// Convert MLIR integer comparison predicate to LLVM IR comparison predicate.
static llvm::CmpInst::Predicate getLLVMCmpPredicate(CmpIPredicate p) {
switch (p) {
case CmpIPredicate::EQ:
return llvm::CmpInst::Predicate::ICMP_EQ;
case CmpIPredicate::NE:
return llvm::CmpInst::Predicate::ICMP_NE;
case CmpIPredicate::SLT:
return llvm::CmpInst::Predicate::ICMP_SLT;
case CmpIPredicate::SLE:
return llvm::CmpInst::Predicate::ICMP_SLE;
case CmpIPredicate::SGT:
return llvm::CmpInst::Predicate::ICMP_SGT;
case CmpIPredicate::SGE:
return llvm::CmpInst::Predicate::ICMP_SGE;
case CmpIPredicate::ULT:
return llvm::CmpInst::Predicate::ICMP_ULT;
case CmpIPredicate::ULE:
return llvm::CmpInst::Predicate::ICMP_ULE;
case CmpIPredicate::UGT:
return llvm::CmpInst::Predicate::ICMP_UGT;
case CmpIPredicate::UGE:
return llvm::CmpInst::Predicate::ICMP_UGE;
default:
llvm_unreachable("incorrect comparison predicate");
}
}
// A helper to look up remapped operands in the value remapping table.
template <typename Range>
SmallVector<llvm::Value *, 8> ModuleTranslation::lookupValues(Range &&values) {
SmallVector<llvm::Value *, 8> remapped;
remapped.reserve(llvm::size(values));
for (Value *v : values) {
remapped.push_back(valueMapping.lookup(v));
}
return remapped;
}
// Given a single MLIR operation, create the corresponding LLVM IR operation
// using the `builder`. LLVM IR Builder does not have a generic interface so
// this has to be a long chain of `if`s calling different functions with a
// different number of arguments.
bool ModuleTranslation::convertOperation(Operation &opInst,
llvm::IRBuilder<> &builder) {
auto extractPosition = [](ArrayAttr attr) {
SmallVector<unsigned, 4> position;
position.reserve(attr.size());
for (Attribute v : attr)
position.push_back(v.cast<IntegerAttr>().getValue().getZExtValue());
return position;
};
#include "mlir/LLVMIR/LLVMConversions.inc"
// Emit function calls. If the "callee" attribute is present, this is a
// direct function call and we also need to look up the remapped function
// itself. Otherwise, this is an indirect call and the callee is the first
// operand, look it up as a normal value. Return the llvm::Value representing
// the function result, which may be of llvm::VoidTy type.
auto convertCall = [this, &builder](Operation &op) -> llvm::Value * {
auto operands = lookupValues(op.getOperands());
ArrayRef<llvm::Value *> operandsRef(operands);
if (auto attr = op.getAttrOfType<FunctionAttr>("callee")) {
return builder.CreateCall(functionMapping.lookup(attr.getValue()),
operandsRef);
} else {
return builder.CreateCall(operandsRef.front(), operandsRef.drop_front());
}
};
// Emit calls. If the called function has a result, remap the corresponding
// value. Note that LLVM IR dialect CallOp has either 0 or 1 result.
if (opInst.isa<LLVM::CallOp>()) {
llvm::Value *result = convertCall(opInst);
if (opInst.getNumResults() != 0) {
valueMapping[opInst.getResult(0)] = result;
return false;
}
// Check that LLVM call returns void for 0-result functions.
return !result->getType()->isVoidTy();
}
// Emit branches. We need to look up the remapped blocks and ignore the block
// arguments that were transformed into PHI nodes.
if (auto brOp = opInst.dyn_cast<LLVM::BrOp>()) {
builder.CreateBr(blockMapping[brOp.getSuccessor(0)]);
return false;
}
if (auto condbrOp = opInst.dyn_cast<LLVM::CondBrOp>()) {
builder.CreateCondBr(valueMapping.lookup(condbrOp.getOperand(0)),
blockMapping[condbrOp.getSuccessor(0)],
blockMapping[condbrOp.getSuccessor(1)]);
return false;
}
opInst.emitError("unsupported or non-LLVM operation: " +
opInst.getName().getStringRef());
return true;
}
// Convert block to LLVM IR. Unless `ignoreArguments` is set, emit PHI nodes
// to define values corresponding to the MLIR block arguments. These nodes
// are not connected to the source basic blocks, which may not exist yet.
bool ModuleTranslation::convertBlock(Block &bb, bool ignoreArguments) {
llvm::IRBuilder<> builder(blockMapping[&bb]);
// Before traversing operations, make block arguments available through
// value remapping and PHI nodes, but do not add incoming edges for the PHI
// nodes just yet: those values may be defined by this or following blocks.
// This step is omitted if "ignoreArguments" is set. The arguments of the
// first block have been already made available through the remapping of
// LLVM function arguments.
if (!ignoreArguments) {
auto predecessors = bb.getPredecessors();
unsigned numPredecessors =
std::distance(predecessors.begin(), predecessors.end());
for (auto *arg : bb.getArguments()) {
auto wrappedType = arg->getType().dyn_cast<LLVM::LLVMType>();
if (!wrappedType) {
arg->getType().getContext()->emitError(
bb.front().getLoc(), "block argument does not have an LLVM type");
return true;
}
llvm::Type *type = wrappedType.getUnderlyingType();
llvm::PHINode *phi = builder.CreatePHI(type, numPredecessors);
valueMapping[arg] = phi;
}
}
// Traverse operations.
for (auto &op : bb) {
if (convertOperation(op, builder))
return true;
}
return false;
}
// Get the SSA value passed to the current block from the terminator operation
// of its predecessor.
static Value *getPHISourceValue(Block *current, Block *pred,
unsigned numArguments, unsigned index) {
auto &terminator = *pred->getTerminator();
if (terminator.isa<LLVM::BrOp>()) {
return terminator.getOperand(index);
}
// For conditional branches, we need to check if the current block is reached
// through the "true" or the "false" branch and take the relevant operands.
auto condBranchOp = terminator.dyn_cast<LLVM::CondBrOp>();
assert(condBranchOp &&
"only branch operations can be terminators of a block that "
"has successors");
assert((condBranchOp.getSuccessor(0) != condBranchOp.getSuccessor(1)) &&
"successors with arguments in LLVM conditional branches must be "
"different blocks");
return condBranchOp.getSuccessor(0) == current
? terminator.getSuccessorOperand(0, index)
: terminator.getSuccessorOperand(1, index);
}
void ModuleTranslation::connectPHINodes(Function &func) {
// Skip the first block, it cannot be branched to and its arguments correspond
// to the arguments of the LLVM function.
for (auto it = std::next(func.begin()), eit = func.end(); it != eit; ++it) {
Block *bb = &*it;
llvm::BasicBlock *llvmBB = blockMapping.lookup(bb);
auto phis = llvmBB->phis();
auto numArguments = bb->getNumArguments();
assert(numArguments == std::distance(phis.begin(), phis.end()));
for (auto &numberedPhiNode : llvm::enumerate(phis)) {
auto &phiNode = numberedPhiNode.value();
unsigned index = numberedPhiNode.index();
for (auto *pred : bb->getPredecessors()) {
phiNode.addIncoming(valueMapping.lookup(getPHISourceValue(
bb, pred, numArguments, index)),
blockMapping.lookup(pred));
}
}
}
}
// TODO(mlir-team): implement an iterative version
static void topologicalSortImpl(llvm::SetVector<Block *> &blocks, Block *b) {
blocks.insert(b);
for (Block *bb : b->getSuccessors()) {
if (blocks.count(bb) == 0)
topologicalSortImpl(blocks, bb);
}
}
// Sort function blocks topologically.
static llvm::SetVector<Block *> topologicalSort(Function &f) {
// For each blocks that has not been visited yet (i.e. that has no
// predecessors), add it to the list and traverse its successors in DFS
// preorder.
llvm::SetVector<Block *> blocks;
for (Block &b : f.getBlocks()) {
if (blocks.count(&b) == 0)
topologicalSortImpl(blocks, &b);
}
assert(blocks.size() == f.getBlocks().size() && "some blocks are not sorted");
return blocks;
}
bool ModuleTranslation::convertOneFunction(Function &func) {
// Clear the block and value mappings, they are only relevant within one
// function.
blockMapping.clear();
valueMapping.clear();
llvm::Function *llvmFunc = functionMapping.lookup(&func);
// Add function arguments to the value remapping table.
// If there was noalias info then we decorate each argument accordingly.
unsigned int argIdx = 0;
for (const auto &kvp : llvm::zip(func.getArguments(), llvmFunc->args())) {
llvm::Argument &llvmArg = std::get<1>(kvp);
BlockArgument *mlirArg = std::get<0>(kvp);
if (auto attr = func.getArgAttrOfType<BoolAttr>(argIdx, "llvm.noalias")) {
// NB: Attribute already verified to be boolean, so check if we can indeed
// attach the attribute to this argument, based on its type.
auto argTy = mlirArg->getType().dyn_cast<LLVM::LLVMType>();
if (!argTy.getUnderlyingType()->isPointerTy())
return argTy.getContext()->emitError(
func.getLoc(),
"llvm.noalias attribute attached to LLVM non-pointer argument");
if (attr.getValue())
llvmArg.addAttr(llvm::Attribute::AttrKind::NoAlias);
}
valueMapping[mlirArg] = &llvmArg;
argIdx++;
}
// First, create all blocks so we can jump to them.
llvm::LLVMContext &llvmContext = llvmFunc->getContext();
for (auto &bb : func) {
auto *llvmBB = llvm::BasicBlock::Create(llvmContext);
llvmBB->insertInto(llvmFunc);
blockMapping[&bb] = llvmBB;
}
// Then, convert blocks one by one in topological order to ensure defs are
// converted before uses.
auto blocks = topologicalSort(func);
for (auto indexedBB : llvm::enumerate(blocks)) {
auto *bb = indexedBB.value();
if (convertBlock(*bb, /*ignoreArguments=*/indexedBB.index() == 0))
return true;
}
// Finally, after all blocks have been traversed and values mapped, connect
// the PHI nodes to the results of preceding blocks.
connectPHINodes(func);
return false;
}
bool ModuleTranslation::convertFunctions() {
// Declare all functions first because there may be function calls that form a
// call graph with cycles.
for (Function &function : mlirModule) {
Function *functionPtr = &function;
mlir::BoolAttr isVarArgsAttr =
function.getAttrOfType<BoolAttr>("std.varargs");
bool isVarArgs = isVarArgsAttr && isVarArgsAttr.getValue();
llvm::FunctionType *functionType =
convertFunctionType(llvmModule->getContext(), function.getType(),
function.getLoc(), isVarArgs);
if (!functionType)
return true;
llvm::FunctionCallee llvmFuncCst =
llvmModule->getOrInsertFunction(function.getName(), functionType);
assert(isa<llvm::Function>(llvmFuncCst.getCallee()));
functionMapping[functionPtr] =
cast<llvm::Function>(llvmFuncCst.getCallee());
}
// Convert functions.
for (Function &function : mlirModule) {
// Ignore external functions.
if (function.isExternal())
continue;
if (convertOneFunction(function))
return true;
}
return false;
}
std::unique_ptr<llvm::Module> ModuleTranslation::translateModule(Module &m) {
Dialect *dialect = m.getContext()->getRegisteredDialect("llvm");
assert(dialect && "LLVM dialect must be registered");
auto *llvmDialect = static_cast<LLVM::LLVMDialect *>(dialect);
auto llvmModule = llvm::CloneModule(llvmDialect->getLLVMModule());
if (!llvmModule)
return nullptr;
llvm::LLVMContext &llvmContext = llvmModule->getContext();
llvm::IRBuilder<> builder(llvmContext);
// Inject declarations for `malloc` and `free` functions that can be used in
// memref allocation/deallocation coming from standard ops lowering.
llvmModule->getOrInsertFunction("malloc", builder.getInt8PtrTy(),
builder.getInt64Ty());
llvmModule->getOrInsertFunction("free", builder.getVoidTy(),
builder.getInt8PtrTy());
ModuleTranslation translator(m);
translator.llvmModule = std::move(llvmModule);
if (translator.convertFunctions())
return nullptr;
return std::move(translator.llvmModule);
}
std::unique_ptr<llvm::Module> mlir::translateModuleToLLVMIR(Module &m) {
return ModuleTranslation::translateModule(m);
return LLVM::ModuleTranslation::translateModule<>(m);
}
static TranslateFromMLIRRegistration registration(
@ -481,7 +40,7 @@ static TranslateFromMLIRRegistration registration(
if (!module)
return true;
auto llvmModule = ModuleTranslation::translateModule(*module);
auto llvmModule = LLVM::ModuleTranslation::translateModule<>(*module);
if (!llvmModule)
return true;

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@ -0,0 +1,84 @@
//===- ConvertToNVVMIR.cpp - MLIR to LLVM IR conversion ---------*- C++ -*-===//
//
// Copyright 2019 The MLIR Authors.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
// =============================================================================
//
// This file implements a translation between the MLIR LLVM + NVVM dialects and
// LLVM IR with NVVM intrinsics and metadata.
//
//===----------------------------------------------------------------------===//
#include "mlir/Target/NVVMIR.h"
#include "mlir/LLVMIR/NVVMDialect.h"
#include "mlir/Support/FileUtilities.h"
#include "mlir/Target/LLVMIR/ModuleTranslation.h"
#include "mlir/Translation.h"
#include "llvm/ADT/StringRef.h"
#include "llvm/IR/Module.h"
#include "llvm/Support/ToolOutputFile.h"
using namespace mlir;
namespace {
static void createIntrinsicCall(llvm::IRBuilder<> &builder,
llvm::Intrinsic::ID intrinsic) {
llvm::Module *module = builder.GetInsertBlock()->getModule();
llvm::Function *fn = llvm::Intrinsic::getDeclaration(module, intrinsic, {});
builder.CreateCall(fn);
}
class ModuleTranslation : public LLVM::ModuleTranslation {
public:
explicit ModuleTranslation(Module &module)
: LLVM::ModuleTranslation(module) {}
~ModuleTranslation() override {}
protected:
bool convertOperation(Operation &opInst,
llvm::IRBuilder<> &builder) override {
#include "mlir/LLVMIR/NVVMConversions.inc"
return LLVM::ModuleTranslation::convertOperation(opInst, builder);
}
};
} // namespace
std::unique_ptr<llvm::Module> mlir::translateModuleToNVVMIR(Module &m) {
ModuleTranslation translation(m);
return LLVM::ModuleTranslation::translateModule<ModuleTranslation>(m);
}
static TranslateFromMLIRRegistration registration(
"mlir-to-nvvmir", [](Module *module, llvm::StringRef outputFilename) {
if (!module)
return true;
auto llvmModule =
LLVM::ModuleTranslation::translateModule<ModuleTranslation>(*module);
if (!llvmModule)
return true;
auto file = openOutputFile(outputFilename);
if (!file)
return true;
llvmModule->print(file->os(), nullptr);
file->keep();
return false;
});

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@ -0,0 +1,432 @@
//===- ModuleTranslation.cpp - MLIR to LLVM conversion ----------*- C++ -*-===//
//
// Copyright 2019 The MLIR Authors.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
// =============================================================================
//
// This file implements the translation between an MLIR LLVM dialect module and
// the corresponding LLVMIR module. It only handles core LLVM IR operations.
//
//===----------------------------------------------------------------------===//
#include "mlir/Target/LLVMIR/ModuleTranslation.h"
#include "mlir/IR/Attributes.h"
#include "mlir/IR/Module.h"
#include "mlir/LLVMIR/LLVMDialect.h"
#include "mlir/StandardOps/Ops.h"
#include "mlir/Support/LLVM.h"
#include "llvm/ADT/SetVector.h"
#include "llvm/IR/BasicBlock.h"
#include "llvm/IR/Constants.h"
#include "llvm/IR/DerivedTypes.h"
#include "llvm/IR/IRBuilder.h"
#include "llvm/IR/LLVMContext.h"
#include "llvm/IR/Module.h"
#include "llvm/Transforms/Utils/Cloning.h"
namespace mlir {
namespace LLVM {
// Convert an MLIR function type to LLVM IR. Arguments of the function must of
// MLIR LLVM IR dialect types. Use `loc` as a location when reporting errors.
// Return nullptr on errors.
static llvm::FunctionType *convertFunctionType(llvm::LLVMContext &llvmContext,
FunctionType type, Location loc,
bool isVarArgs) {
assert(type && "expected non-null type");
auto context = type.getContext();
if (type.getNumResults() > 1)
return context->emitError(loc,
"LLVM functions can only have 0 or 1 result"),
nullptr;
SmallVector<llvm::Type *, 8> argTypes;
argTypes.reserve(type.getNumInputs());
for (auto t : type.getInputs()) {
auto wrappedLLVMType = t.dyn_cast<LLVM::LLVMType>();
if (!wrappedLLVMType)
return context->emitError(loc, "non-LLVM function argument type"),
nullptr;
argTypes.push_back(wrappedLLVMType.getUnderlyingType());
}
if (type.getNumResults() == 0)
return llvm::FunctionType::get(llvm::Type::getVoidTy(llvmContext), argTypes,
isVarArgs);
auto wrappedResultType = type.getResult(0).dyn_cast<LLVM::LLVMType>();
if (!wrappedResultType)
return context->emitError(loc, "non-LLVM function result"), nullptr;
return llvm::FunctionType::get(wrappedResultType.getUnderlyingType(),
argTypes, isVarArgs);
}
// Create an LLVM IR constant of `llvmType` from the MLIR attribute `attr`.
// This currently supports integer, floating point, splat and dense element
// attributes and combinations thereof. In case of error, report it to `loc`
// and return nullptr.
llvm::Constant *ModuleTranslation::getLLVMConstant(llvm::Type *llvmType,
Attribute attr,
Location loc) {
if (auto intAttr = attr.dyn_cast<IntegerAttr>())
return llvm::ConstantInt::get(llvmType, intAttr.getValue());
if (auto floatAttr = attr.dyn_cast<FloatAttr>())
return llvm::ConstantFP::get(llvmType, floatAttr.getValue());
if (auto funcAttr = attr.dyn_cast<FunctionAttr>())
return functionMapping.lookup(funcAttr.getValue());
if (auto splatAttr = attr.dyn_cast<SplatElementsAttr>()) {
auto *vectorType = cast<llvm::VectorType>(llvmType);
auto *child = getLLVMConstant(vectorType->getElementType(),
splatAttr.getValue(), loc);
return llvm::ConstantVector::getSplat(vectorType->getNumElements(), child);
}
if (auto denseAttr = attr.dyn_cast<DenseElementsAttr>()) {
auto *vectorType = cast<llvm::VectorType>(llvmType);
SmallVector<llvm::Constant *, 8> constants;
uint64_t numElements = vectorType->getNumElements();
constants.reserve(numElements);
SmallVector<Attribute, 8> nested;
denseAttr.getValues(nested);
for (auto n : nested) {
constants.push_back(
getLLVMConstant(vectorType->getElementType(), n, loc));
if (!constants.back())
return nullptr;
}
return llvm::ConstantVector::get(constants);
}
mlirModule.getContext()->emitError(loc, "unsupported constant value");
return nullptr;
}
// Convert MLIR integer comparison predicate to LLVM IR comparison predicate.
static llvm::CmpInst::Predicate getLLVMCmpPredicate(CmpIPredicate p) {
switch (p) {
case CmpIPredicate::EQ:
return llvm::CmpInst::Predicate::ICMP_EQ;
case CmpIPredicate::NE:
return llvm::CmpInst::Predicate::ICMP_NE;
case CmpIPredicate::SLT:
return llvm::CmpInst::Predicate::ICMP_SLT;
case CmpIPredicate::SLE:
return llvm::CmpInst::Predicate::ICMP_SLE;
case CmpIPredicate::SGT:
return llvm::CmpInst::Predicate::ICMP_SGT;
case CmpIPredicate::SGE:
return llvm::CmpInst::Predicate::ICMP_SGE;
case CmpIPredicate::ULT:
return llvm::CmpInst::Predicate::ICMP_ULT;
case CmpIPredicate::ULE:
return llvm::CmpInst::Predicate::ICMP_ULE;
case CmpIPredicate::UGT:
return llvm::CmpInst::Predicate::ICMP_UGT;
case CmpIPredicate::UGE:
return llvm::CmpInst::Predicate::ICMP_UGE;
default:
llvm_unreachable("incorrect comparison predicate");
}
}
// A helper to look up remapped operands in the value remapping table.
template <typename Range>
SmallVector<llvm::Value *, 8> ModuleTranslation::lookupValues(Range &&values) {
SmallVector<llvm::Value *, 8> remapped;
remapped.reserve(llvm::size(values));
for (Value *v : values) {
remapped.push_back(valueMapping.lookup(v));
}
return remapped;
}
// Given a single MLIR operation, create the corresponding LLVM IR operation
// using the `builder`. LLVM IR Builder does not have a generic interface so
// this has to be a long chain of `if`s calling different functions with a
// different number of arguments.
bool ModuleTranslation::convertOperation(Operation &opInst,
llvm::IRBuilder<> &builder) {
auto extractPosition = [](ArrayAttr attr) {
SmallVector<unsigned, 4> position;
position.reserve(attr.size());
for (Attribute v : attr)
position.push_back(v.cast<IntegerAttr>().getValue().getZExtValue());
return position;
};
#include "mlir/LLVMIR/LLVMConversions.inc"
// Emit function calls. If the "callee" attribute is present, this is a
// direct function call and we also need to look up the remapped function
// itself. Otherwise, this is an indirect call and the callee is the first
// operand, look it up as a normal value. Return the llvm::Value representing
// the function result, which may be of llvm::VoidTy type.
auto convertCall = [this, &builder](Operation &op) -> llvm::Value * {
auto operands = lookupValues(op.getOperands());
ArrayRef<llvm::Value *> operandsRef(operands);
if (auto attr = op.getAttrOfType<FunctionAttr>("callee")) {
return builder.CreateCall(functionMapping.lookup(attr.getValue()),
operandsRef);
} else {
return builder.CreateCall(operandsRef.front(), operandsRef.drop_front());
}
};
// Emit calls. If the called function has a result, remap the corresponding
// value. Note that LLVM IR dialect CallOp has either 0 or 1 result.
if (opInst.isa<LLVM::CallOp>()) {
llvm::Value *result = convertCall(opInst);
if (opInst.getNumResults() != 0) {
valueMapping[opInst.getResult(0)] = result;
return false;
}
// Check that LLVM call returns void for 0-result functions.
return !result->getType()->isVoidTy();
}
// Emit branches. We need to look up the remapped blocks and ignore the block
// arguments that were transformed into PHI nodes.
if (auto brOp = opInst.dyn_cast<LLVM::BrOp>()) {
builder.CreateBr(blockMapping[brOp.getSuccessor(0)]);
return false;
}
if (auto condbrOp = opInst.dyn_cast<LLVM::CondBrOp>()) {
builder.CreateCondBr(valueMapping.lookup(condbrOp.getOperand(0)),
blockMapping[condbrOp.getSuccessor(0)],
blockMapping[condbrOp.getSuccessor(1)]);
return false;
}
opInst.emitError("unsupported or non-LLVM operation: " +
opInst.getName().getStringRef());
return true;
}
// Convert block to LLVM IR. Unless `ignoreArguments` is set, emit PHI nodes
// to define values corresponding to the MLIR block arguments. These nodes
// are not connected to the source basic blocks, which may not exist yet.
bool ModuleTranslation::convertBlock(Block &bb, bool ignoreArguments) {
llvm::IRBuilder<> builder(blockMapping[&bb]);
// Before traversing operations, make block arguments available through
// value remapping and PHI nodes, but do not add incoming edges for the PHI
// nodes just yet: those values may be defined by this or following blocks.
// This step is omitted if "ignoreArguments" is set. The arguments of the
// first block have been already made available through the remapping of
// LLVM function arguments.
if (!ignoreArguments) {
auto predecessors = bb.getPredecessors();
unsigned numPredecessors =
std::distance(predecessors.begin(), predecessors.end());
for (auto *arg : bb.getArguments()) {
auto wrappedType = arg->getType().dyn_cast<LLVM::LLVMType>();
if (!wrappedType) {
arg->getType().getContext()->emitError(
bb.front().getLoc(), "block argument does not have an LLVM type");
return true;
}
llvm::Type *type = wrappedType.getUnderlyingType();
llvm::PHINode *phi = builder.CreatePHI(type, numPredecessors);
valueMapping[arg] = phi;
}
}
// Traverse operations.
for (auto &op : bb) {
if (convertOperation(op, builder))
return true;
}
return false;
}
// Get the SSA value passed to the current block from the terminator operation
// of its predecessor.
static Value *getPHISourceValue(Block *current, Block *pred,
unsigned numArguments, unsigned index) {
auto &terminator = *pred->getTerminator();
if (terminator.isa<LLVM::BrOp>()) {
return terminator.getOperand(index);
}
// For conditional branches, we need to check if the current block is reached
// through the "true" or the "false" branch and take the relevant operands.
auto condBranchOp = terminator.dyn_cast<LLVM::CondBrOp>();
assert(condBranchOp &&
"only branch operations can be terminators of a block that "
"has successors");
assert((condBranchOp.getSuccessor(0) != condBranchOp.getSuccessor(1)) &&
"successors with arguments in LLVM conditional branches must be "
"different blocks");
return condBranchOp.getSuccessor(0) == current
? terminator.getSuccessorOperand(0, index)
: terminator.getSuccessorOperand(1, index);
}
void ModuleTranslation::connectPHINodes(Function &func) {
// Skip the first block, it cannot be branched to and its arguments correspond
// to the arguments of the LLVM function.
for (auto it = std::next(func.begin()), eit = func.end(); it != eit; ++it) {
Block *bb = &*it;
llvm::BasicBlock *llvmBB = blockMapping.lookup(bb);
auto phis = llvmBB->phis();
auto numArguments = bb->getNumArguments();
assert(numArguments == std::distance(phis.begin(), phis.end()));
for (auto &numberedPhiNode : llvm::enumerate(phis)) {
auto &phiNode = numberedPhiNode.value();
unsigned index = numberedPhiNode.index();
for (auto *pred : bb->getPredecessors()) {
phiNode.addIncoming(valueMapping.lookup(getPHISourceValue(
bb, pred, numArguments, index)),
blockMapping.lookup(pred));
}
}
}
}
// TODO(mlir-team): implement an iterative version
static void topologicalSortImpl(llvm::SetVector<Block *> &blocks, Block *b) {
blocks.insert(b);
for (Block *bb : b->getSuccessors()) {
if (blocks.count(bb) == 0)
topologicalSortImpl(blocks, bb);
}
}
// Sort function blocks topologically.
static llvm::SetVector<Block *> topologicalSort(Function &f) {
// For each blocks that has not been visited yet (i.e. that has no
// predecessors), add it to the list and traverse its successors in DFS
// preorder.
llvm::SetVector<Block *> blocks;
for (Block &b : f.getBlocks()) {
if (blocks.count(&b) == 0)
topologicalSortImpl(blocks, &b);
}
assert(blocks.size() == f.getBlocks().size() && "some blocks are not sorted");
return blocks;
}
bool ModuleTranslation::convertOneFunction(Function &func) {
// Clear the block and value mappings, they are only relevant within one
// function.
blockMapping.clear();
valueMapping.clear();
llvm::Function *llvmFunc = functionMapping.lookup(&func);
// Add function arguments to the value remapping table.
// If there was noalias info then we decorate each argument accordingly.
unsigned int argIdx = 0;
for (const auto &kvp : llvm::zip(func.getArguments(), llvmFunc->args())) {
llvm::Argument &llvmArg = std::get<1>(kvp);
BlockArgument *mlirArg = std::get<0>(kvp);
if (auto attr = func.getArgAttrOfType<BoolAttr>(argIdx, "llvm.noalias")) {
// NB: Attribute already verified to be boolean, so check if we can indeed
// attach the attribute to this argument, based on its type.
auto argTy = mlirArg->getType().dyn_cast<LLVM::LLVMType>();
if (!argTy.getUnderlyingType()->isPointerTy())
return argTy.getContext()->emitError(
func.getLoc(),
"llvm.noalias attribute attached to LLVM non-pointer argument");
if (attr.getValue())
llvmArg.addAttr(llvm::Attribute::AttrKind::NoAlias);
}
valueMapping[mlirArg] = &llvmArg;
argIdx++;
}
// First, create all blocks so we can jump to them.
llvm::LLVMContext &llvmContext = llvmFunc->getContext();
for (auto &bb : func) {
auto *llvmBB = llvm::BasicBlock::Create(llvmContext);
llvmBB->insertInto(llvmFunc);
blockMapping[&bb] = llvmBB;
}
// Then, convert blocks one by one in topological order to ensure defs are
// converted before uses.
auto blocks = topologicalSort(func);
for (auto indexedBB : llvm::enumerate(blocks)) {
auto *bb = indexedBB.value();
if (convertBlock(*bb, /*ignoreArguments=*/indexedBB.index() == 0))
return true;
}
// Finally, after all blocks have been traversed and values mapped, connect
// the PHI nodes to the results of preceding blocks.
connectPHINodes(func);
return false;
}
bool ModuleTranslation::convertFunctions() {
// Declare all functions first because there may be function calls that form a
// call graph with cycles.
for (Function &function : mlirModule) {
Function *functionPtr = &function;
mlir::BoolAttr isVarArgsAttr =
function.getAttrOfType<BoolAttr>("std.varargs");
bool isVarArgs = isVarArgsAttr && isVarArgsAttr.getValue();
llvm::FunctionType *functionType =
convertFunctionType(llvmModule->getContext(), function.getType(),
function.getLoc(), isVarArgs);
if (!functionType)
return true;
llvm::FunctionCallee llvmFuncCst =
llvmModule->getOrInsertFunction(function.getName(), functionType);
assert(isa<llvm::Function>(llvmFuncCst.getCallee()));
functionMapping[functionPtr] =
cast<llvm::Function>(llvmFuncCst.getCallee());
}
// Convert functions.
for (Function &function : mlirModule) {
// Ignore external functions.
if (function.isExternal())
continue;
if (convertOneFunction(function))
return true;
}
return false;
}
std::unique_ptr<llvm::Module> ModuleTranslation::prepareLLVMModule(Module &m) {
Dialect *dialect = m.getContext()->getRegisteredDialect("llvm");
assert(dialect && "LLVM dialect must be registered");
auto *llvmDialect = static_cast<LLVM::LLVMDialect *>(dialect);
auto llvmModule = llvm::CloneModule(llvmDialect->getLLVMModule());
if (!llvmModule)
return nullptr;
llvm::LLVMContext &llvmContext = llvmModule->getContext();
llvm::IRBuilder<> builder(llvmContext);
// Inject declarations for `malloc` and `free` functions that can be used in
// memref allocation/deallocation coming from standard ops lowering.
llvmModule->getOrInsertFunction("malloc", builder.getInt8PtrTy(),
builder.getInt64Ty());
llvmModule->getOrInsertFunction("free", builder.getVoidTy(),
builder.getInt8PtrTy());
return llvmModule;
}
} // namespace LLVM
} // namespace mlir

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@ -0,0 +1,29 @@
// RUN: mlir-translate -mlir-to-nvvmir %s | FileCheck %s
func @nvvm_special_regs() -> !llvm.i32 {
// CHECK: %1 = call i32 @llvm.nvvm.read.ptx.sreg.tid.x()
%1 = nvvm.read.ptx.sreg.tid.x : !llvm.i32
// CHECK: %2 = call i32 @llvm.nvvm.read.ptx.sreg.tid.y()
%2 = nvvm.read.ptx.sreg.tid.y : !llvm.i32
// CHECK: %3 = call i32 @llvm.nvvm.read.ptx.sreg.tid.z()
%3 = nvvm.read.ptx.sreg.tid.z : !llvm.i32
// CHECK: %4 = call i32 @llvm.nvvm.read.ptx.sreg.ntid.x()
%4 = nvvm.read.ptx.sreg.ntid.x : !llvm.i32
// CHECK: %5 = call i32 @llvm.nvvm.read.ptx.sreg.ntid.y()
%5 = nvvm.read.ptx.sreg.ntid.y : !llvm.i32
// CHECK: %6 = call i32 @llvm.nvvm.read.ptx.sreg.ntid.z()
%6 = nvvm.read.ptx.sreg.ntid.z : !llvm.i32
// CHECK: %7 = call i32 @llvm.nvvm.read.ptx.sreg.ctaid.x()
%7 = nvvm.read.ptx.sreg.ctaid.x : !llvm.i32
// CHECK: %8 = call i32 @llvm.nvvm.read.ptx.sreg.ctaid.y()
%8 = nvvm.read.ptx.sreg.ctaid.y : !llvm.i32
// CHECK: %9 = call i32 @llvm.nvvm.read.ptx.sreg.ctaid.z()
%9 = nvvm.read.ptx.sreg.ctaid.z : !llvm.i32
// CHECK: %10 = call i32 @llvm.nvvm.read.ptx.sreg.nctaid.x()
%10 = nvvm.read.ptx.sreg.nctaid.x : !llvm.i32
// CHECK: %11 = call i32 @llvm.nvvm.read.ptx.sreg.nctaid.y()
%11 = nvvm.read.ptx.sreg.nctaid.y : !llvm.i32
// CHECK: %12 = call i32 @llvm.nvvm.read.ptx.sreg.nctaid.z()
%12 = nvvm.read.ptx.sreg.nctaid.z : !llvm.i32
llvm.return %1 : !llvm.i32
}

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@ -5,6 +5,7 @@ set(LIBS
MLIRExecutionEngine
MLIRIR
MLIRParser
MLIRTargetLLVMIR
MLIRTransforms
MLIRSupport
LLVMCore

View File

@ -6,6 +6,7 @@ set(LIBS
MLIRPass
MLIRStandardOps
MLIRTargetLLVMIR
MLIRTargetNVVMIR
MLIRTransforms
MLIRTranslation
MLIRSupport

View File

@ -73,7 +73,7 @@ using TranslateFunction =
std::function<bool(StringRef, StringRef, MLIRContext *)>;
// Storage for the translation function wrappers that survive the parser.
static llvm::SmallVector<TranslateFunction, 8> wrapperStorage;
static llvm::SmallVector<TranslateFunction, 16> wrapperStorage;
// Custom parser for TranslateFunction.
// Wraps TranslateToMLIRFunctions and TranslateFromMLIRFunctions into