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//===- ModuleImport.cpp - LLVM to MLIR conversion ---------------*- C++ -*-===//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
// This file implements the import of an LLVM IR module into an LLVM dialect
// module.
#include "mlir/Target/LLVMIR/ModuleImport.h"
#include "mlir/Target/LLVMIR/Import.h"
#include "DebugImporter.h"
#include "mlir/Dialect/DLTI/DLTI.h"
#include "mlir/Dialect/LLVMIR/LLVMDialect.h"
#include "mlir/IR/Matchers.h"
#include "mlir/Interfaces/DataLayoutInterfaces.h"
#include "mlir/Tools/mlir-translate/Translation.h"
#include "llvm/ADT/PostOrderIterator.h"
#include "llvm/ADT/ScopeExit.h"
#include "llvm/ADT/StringSet.h"
#include "llvm/IR/Constants.h"
#include "llvm/IR/InlineAsm.h"
#include "llvm/IR/InstIterator.h"
#include "llvm/IR/Instructions.h"
#include "llvm/IR/IntrinsicInst.h"
#include "llvm/IR/Metadata.h"
#include "llvm/IR/Operator.h"
#include "llvm/Support/ModRef.h"
using namespace mlir;
using namespace mlir::LLVM;
using namespace mlir::LLVM::detail;
#include "mlir/Dialect/LLVMIR/"
// Utility to print an LLVM value as a string for passing to emitError().
// FIXME: Diagnostic should be able to natively handle types that have
// operator << (raw_ostream&) defined.
static std::string diag(const llvm::Value &value) {
std::string str;
llvm::raw_string_ostream os(str);
os << value;
return os.str();
// Utility to print an LLVM metadata node as a string for passing
// to emitError(). The module argument is needed to print the nodes
// canonically numbered.
static std::string diagMD(const llvm::Metadata *node,
const llvm::Module *module) {
std::string str;
llvm::raw_string_ostream os(str);
node->print(os, module, /*IsForDebug=*/true);
return os.str();
/// Returns the name of the global_ctors global variables.
static constexpr StringRef getGlobalCtorsVarName() {
return "llvm.global_ctors";
/// Returns the name of the global_dtors global variables.
static constexpr StringRef getGlobalDtorsVarName() {
return "llvm.global_dtors";
/// Returns a supported MLIR floating point type of the given bit width or null
/// if the bit width is not supported.
static FloatType getDLFloatType(MLIRContext &ctx, int32_t bitwidth) {
switch (bitwidth) {
case 16:
return FloatType::getF16(&ctx);
case 32:
return FloatType::getF32(&ctx);
case 64:
return FloatType::getF64(&ctx);
case 80:
return FloatType::getF80(&ctx);
case 128:
return FloatType::getF128(&ctx);
return nullptr;
static ICmpPredicate getICmpPredicate(llvm::CmpInst::Predicate pred) {
switch (pred) {
llvm_unreachable("incorrect comparison predicate");
case llvm::CmpInst::Predicate::ICMP_EQ:
return LLVM::ICmpPredicate::eq;
case llvm::CmpInst::Predicate::ICMP_NE:
return LLVM::ICmpPredicate::ne;
case llvm::CmpInst::Predicate::ICMP_SLT:
return LLVM::ICmpPredicate::slt;
case llvm::CmpInst::Predicate::ICMP_SLE:
return LLVM::ICmpPredicate::sle;
case llvm::CmpInst::Predicate::ICMP_SGT:
return LLVM::ICmpPredicate::sgt;
case llvm::CmpInst::Predicate::ICMP_SGE:
return LLVM::ICmpPredicate::sge;
case llvm::CmpInst::Predicate::ICMP_ULT:
return LLVM::ICmpPredicate::ult;
case llvm::CmpInst::Predicate::ICMP_ULE:
return LLVM::ICmpPredicate::ule;
case llvm::CmpInst::Predicate::ICMP_UGT:
return LLVM::ICmpPredicate::ugt;
case llvm::CmpInst::Predicate::ICMP_UGE:
return LLVM::ICmpPredicate::uge;
llvm_unreachable("incorrect integer comparison predicate");
static FCmpPredicate getFCmpPredicate(llvm::CmpInst::Predicate pred) {
switch (pred) {
llvm_unreachable("incorrect comparison predicate");
case llvm::CmpInst::Predicate::FCMP_FALSE:
return LLVM::FCmpPredicate::_false;
case llvm::CmpInst::Predicate::FCMP_TRUE:
return LLVM::FCmpPredicate::_true;
case llvm::CmpInst::Predicate::FCMP_OEQ:
return LLVM::FCmpPredicate::oeq;
case llvm::CmpInst::Predicate::FCMP_ONE:
return LLVM::FCmpPredicate::one;
case llvm::CmpInst::Predicate::FCMP_OLT:
return LLVM::FCmpPredicate::olt;
case llvm::CmpInst::Predicate::FCMP_OLE:
return LLVM::FCmpPredicate::ole;
case llvm::CmpInst::Predicate::FCMP_OGT:
return LLVM::FCmpPredicate::ogt;
case llvm::CmpInst::Predicate::FCMP_OGE:
return LLVM::FCmpPredicate::oge;
case llvm::CmpInst::Predicate::FCMP_ORD:
return LLVM::FCmpPredicate::ord;
case llvm::CmpInst::Predicate::FCMP_ULT:
return LLVM::FCmpPredicate::ult;
case llvm::CmpInst::Predicate::FCMP_ULE:
return LLVM::FCmpPredicate::ule;
case llvm::CmpInst::Predicate::FCMP_UGT:
return LLVM::FCmpPredicate::ugt;
case llvm::CmpInst::Predicate::FCMP_UGE:
return LLVM::FCmpPredicate::uge;
case llvm::CmpInst::Predicate::FCMP_UNO:
return LLVM::FCmpPredicate::uno;
case llvm::CmpInst::Predicate::FCMP_UEQ:
return LLVM::FCmpPredicate::ueq;
case llvm::CmpInst::Predicate::FCMP_UNE:
return LLVM::FCmpPredicate::une;
llvm_unreachable("incorrect floating point comparison predicate");
static AtomicOrdering getLLVMAtomicOrdering(llvm::AtomicOrdering ordering) {
switch (ordering) {
case llvm::AtomicOrdering::NotAtomic:
return LLVM::AtomicOrdering::not_atomic;
case llvm::AtomicOrdering::Unordered:
return LLVM::AtomicOrdering::unordered;
case llvm::AtomicOrdering::Monotonic:
return LLVM::AtomicOrdering::monotonic;
case llvm::AtomicOrdering::Acquire:
return LLVM::AtomicOrdering::acquire;
case llvm::AtomicOrdering::Release:
return LLVM::AtomicOrdering::release;
case llvm::AtomicOrdering::AcquireRelease:
return LLVM::AtomicOrdering::acq_rel;
case llvm::AtomicOrdering::SequentiallyConsistent:
return LLVM::AtomicOrdering::seq_cst;
llvm_unreachable("incorrect atomic ordering");
static AtomicBinOp getLLVMAtomicBinOp(llvm::AtomicRMWInst::BinOp binOp) {
switch (binOp) {
case llvm::AtomicRMWInst::Xchg:
return LLVM::AtomicBinOp::xchg;
case llvm::AtomicRMWInst::Add:
return LLVM::AtomicBinOp::add;
case llvm::AtomicRMWInst::Sub:
return LLVM::AtomicBinOp::sub;
case llvm::AtomicRMWInst::And:
return LLVM::AtomicBinOp::_and;
case llvm::AtomicRMWInst::Nand:
return LLVM::AtomicBinOp::nand;
case llvm::AtomicRMWInst::Or:
return LLVM::AtomicBinOp::_or;
case llvm::AtomicRMWInst::Xor:
return LLVM::AtomicBinOp::_xor;
case llvm::AtomicRMWInst::Max:
return LLVM::AtomicBinOp::max;
case llvm::AtomicRMWInst::Min:
return LLVM::AtomicBinOp::min;
case llvm::AtomicRMWInst::UMax:
return LLVM::AtomicBinOp::umax;
case llvm::AtomicRMWInst::UMin:
return LLVM::AtomicBinOp::umin;
case llvm::AtomicRMWInst::FAdd:
return LLVM::AtomicBinOp::fadd;
case llvm::AtomicRMWInst::FSub:
return LLVM::AtomicBinOp::fsub;
llvm_unreachable("unsupported atomic binary operation");
/// Converts the sync scope identifier of `fenceInst` to the string
/// representation necessary to build the LLVM dialect fence operation.
static StringRef getLLVMSyncScope(llvm::FenceInst *fenceInst) {
llvm::LLVMContext &llvmContext = fenceInst->getContext();
SmallVector<StringRef> syncScopeNames;
for (StringRef name : syncScopeNames)
if (fenceInst->getSyncScopeID() == llvmContext.getOrInsertSyncScopeID(name))
return name;
llvm_unreachable("incorrect sync scope identifier");
/// Converts an array of unsigned indices to a signed integer position array.
static SmallVector<int64_t> getPositionFromIndices(ArrayRef<unsigned> indices) {
SmallVector<int64_t> position;
llvm::append_range(position, indices);
return position;
/// Converts the LLVM instructions that have a generated MLIR builder. Using a
/// static implementation method called from the module import ensures the
/// builders have to use the `moduleImport` argument and cannot directly call
/// import methods. As a result, both the intrinsic and the instruction MLIR
/// builders have to use the `moduleImport` argument and none of them has direct
/// access to the private module import methods.
static LogicalResult convertInstructionImpl(OpBuilder &odsBuilder,
llvm::Instruction *inst,
ModuleImport &moduleImport) {
// Copy the operands to an LLVM operands array reference for conversion.
SmallVector<llvm::Value *> operands(inst->operands());
ArrayRef<llvm::Value *> llvmOperands(operands);
// Convert all instructions that provide an MLIR builder.
#include "mlir/Dialect/LLVMIR/"
return failure();
/// Creates an attribute containing ABI and preferred alignment numbers parsed
/// a string. The string may be either "abi:preferred" or just "abi". In the
/// latter case, the preferred alignment is considered equal to ABI alignment.
static DenseIntElementsAttr parseDataLayoutAlignment(MLIRContext &ctx,
StringRef spec) {
auto i32 = IntegerType::get(&ctx, 32);
StringRef abiString, preferredString;
std::tie(abiString, preferredString) = spec.split(':');
int abi, preferred;
if (abiString.getAsInteger(/*Radix=*/10, abi))
return nullptr;
if (preferredString.empty())
preferred = abi;
else if (preferredString.getAsInteger(/*Radix=*/10, preferred))
return nullptr;
return DenseIntElementsAttr::get(VectorType::get({2}, i32), {abi, preferred});
/// Translate the given LLVM data layout into an MLIR equivalent using the DLTI
/// dialect.
mlir::translateDataLayout(const llvm::DataLayout &dataLayout,
MLIRContext *context) {
assert(context && "expected MLIR context");
std::string layoutstr = dataLayout.getStringRepresentation();
// Remaining unhandled default layout defaults
// e (little endian if not set)
// p[n]:64:64:64 (non zero address spaces have 64-bit properties)
std::string append =
if (layoutstr.empty())
layoutstr = append;
layoutstr = layoutstr + "-" + append;
StringRef layout(layoutstr);
SmallVector<DataLayoutEntryInterface> entries;
StringSet<> seen;
while (!layout.empty()) {
// Split at '-'.
std::pair<StringRef, StringRef> split = layout.split('-');
StringRef current;
std::tie(current, layout) = split;
// Split at ':'.
StringRef kind, spec;
std::tie(kind, spec) = current.split(':');
if (seen.contains(kind))
char symbol = kind.front();
StringRef parameter = kind.substr(1);
if (symbol == 'i' || symbol == 'f') {
unsigned bitwidth;
if (parameter.getAsInteger(/*Radix=*/10, bitwidth))
return nullptr;
DenseIntElementsAttr params = parseDataLayoutAlignment(*context, spec);
if (!params)
return nullptr;
auto entry = DataLayoutEntryAttr::get(
symbol == 'i' ? static_cast<Type>(IntegerType::get(context, bitwidth))
: getDLFloatType(*context, bitwidth),
} else if (symbol == 'e' || symbol == 'E') {
auto value = StringAttr::get(
context, symbol == 'e' ? DLTIDialect::kDataLayoutEndiannessLittle
: DLTIDialect::kDataLayoutEndiannessBig);
auto entry = DataLayoutEntryAttr::get(
StringAttr::get(context, DLTIDialect::kDataLayoutEndiannessKey),
return DataLayoutSpecAttr::get(context, entries);
/// Get a topologically sorted list of blocks for the given function.
static SetVector<llvm::BasicBlock *>
getTopologicallySortedBlocks(llvm::Function *func) {
SetVector<llvm::BasicBlock *> blocks;
for (llvm::BasicBlock &bb : *func) {
if (blocks.count(&bb) == 0) {
llvm::ReversePostOrderTraversal<llvm::BasicBlock *> traversal(&bb);
blocks.insert(traversal.begin(), traversal.end());
assert(blocks.size() == func->size() && "some blocks are not sorted");
return blocks;
ModuleImport::ModuleImport(ModuleOp mlirModule,
std::unique_ptr<llvm::Module> llvmModule)
: builder(mlirModule->getContext()), context(mlirModule->getContext()),
mlirModule(mlirModule), llvmModule(std::move(llvmModule)),
debugImporter(std::make_unique<DebugImporter>(mlirModule)) {
MetadataOp ModuleImport::getTBAAMetadataOp() {
if (tbaaMetadataOp)
return tbaaMetadataOp;
OpBuilder::InsertionGuard guard(builder);
Location loc = mlirModule.getLoc();
tbaaMetadataOp = builder.create<MetadataOp>(loc, getTBAAMetadataOpName());
return tbaaMetadataOp;
std::string ModuleImport::getNewTBAANodeName(StringRef basename) {
return (Twine("tbaa_") + Twine(basename) + Twine('_') +
LogicalResult ModuleImport::processTBAAMetadata(const llvm::MDNode *node) {
Location loc = mlirModule.getLoc();
SmallVector<const llvm::MDNode *> workList;
SetVector<const llvm::MDNode *> nodesToConvert;
while (!workList.empty()) {
const llvm::MDNode *current = workList.pop_back_val();
if (tbaaMapping.count(current))
// Allow cycles in TBAA metadata. Just import it as-is,
// and diagnose the problem during LLVMIR dialect verification.
if (!nodesToConvert.insert(current))
for (const llvm::MDOperand &operand : current->operands())
if (auto *opNode = dyn_cast_or_null<const llvm::MDNode>(operand.get()))
// If `node` is a valid TBAA root node, then return its identity
// string, otherwise return std::nullopt.
auto getIdentityIfRootNode =
[&](const llvm::MDNode *node) -> std::optional<StringRef> {
// Root node, e.g.:
// !0 = !{!"Simple C/C++ TBAA"}
if (node->getNumOperands() != 1)
return std::nullopt;
// If the operand is MDString, then assume that this is a root node.
if (const auto *op0 = dyn_cast<const llvm::MDString>(node->getOperand(0)))
return op0->getString();
return std::nullopt;
// If `node` looks like a TBAA type descriptor metadata,
// then return true, if it is a valid node, and false otherwise.
// If it does not look like a TBAA type descriptor metadata, then
// return std::nullopt.
// If `identity` and `memberTypes/Offsets` are non-null, then they will
// contain the converted metadata operands for a valid TBAA node (i.e. when
// true is returned).
auto isTypeDescriptorNode =
[&](const llvm::MDNode *node, StringRef *identity = nullptr,
SmallVectorImpl<Attribute> *memberTypes = nullptr,
SmallVectorImpl<int64_t> *memberOffsets =
nullptr) -> std::optional<bool> {
unsigned numOperands = node->getNumOperands();
// Type descriptor, e.g.:
// !1 = !{!"int", !0, /*optional*/i64 0} /* scalar int type */
// !2 = !{!"agg_t", !1, i64 0} /* struct agg_t { int x; } */
if (numOperands < 2)
return std::nullopt;
// TODO: support "new" format (D41501) for type descriptors,
// where the first operand is an MDNode.
const auto *identityNode =
dyn_cast<const llvm::MDString>(node->getOperand(0));
if (!identityNode)
return std::nullopt;
// This should be a type descriptor node.
if (identity)
*identity = identityNode->getString();
for (unsigned pairNum = 0, e = numOperands / 2; pairNum < e; ++pairNum) {
const auto *memberNode =
dyn_cast<const llvm::MDNode>(node->getOperand(2 * pairNum + 1));
if (!memberNode) {
emitError(loc) << "operand '" << 2 * pairNum + 1 << "' must be MDNode: "
<< diagMD(node, llvmModule.get());
return false;
int64_t offset = 0;
if (2 * pairNum + 2 >= numOperands) {
// Allow for optional 0 offset in 2-operand nodes.
if (numOperands != 2) {
emitError(loc) << "missing member offset: "
<< diagMD(node, llvmModule.get());
return false;
} else {
auto *offsetCI = llvm::mdconst::dyn_extract<llvm::ConstantInt>(
node->getOperand(2 * pairNum + 2));
if (!offsetCI) {
emitError(loc) << "operand '" << 2 * pairNum + 2
<< "' must be ConstantInt: "
<< diagMD(node, llvmModule.get());
return false;
offset = offsetCI->getZExtValue();
if (memberTypes)
if (memberOffsets)
return true;
// If `node` looks like a TBAA access tag metadata,
// then return true, if it is a valid node, and false otherwise.
// If it does not look like a TBAA access tag metadata, then
// return std::nullopt.
// If the other arguments are non-null, then they will contain
// the converted metadata operands for a valid TBAA node (i.e. when true is
// returned).
auto isTagNode =
[&](const llvm::MDNode *node, SymbolRefAttr *baseSymRef = nullptr,
SymbolRefAttr *accessSymRef = nullptr, int64_t *offset = nullptr,
bool *isConstant = nullptr) -> std::optional<bool> {
// Access tag, e.g.:
// !3 = !{!1, !1, i64 0} /* scalar int access */
// !4 = !{!2, !1, i64 0} /* agg_t::x access */
// Optional 4th argument is ConstantInt 0/1 identifying whether
// the location being accessed is "constant" (see for details:
unsigned numOperands = node->getNumOperands();
if (numOperands != 3 && numOperands != 4)
return std::nullopt;
const auto *baseMD = dyn_cast<const llvm::MDNode>(node->getOperand(0));
const auto *accessMD = dyn_cast<const llvm::MDNode>(node->getOperand(1));
auto *offsetCI =
if (!baseMD || !accessMD || !offsetCI)
return std::nullopt;
// TODO: support "new" TBAA format, if needed (see D41501).
// In the "old" format the first operand of the access type
// metadata is MDString. We have to distinguish the formats,
// because access tags have the same structure, but different
// meaning for the operands.
if (accessMD->getNumOperands() < 1 ||
return std::nullopt;
bool isConst = false;
if (numOperands == 4) {
auto *isConstantCI =
if (!isConstantCI) {
emitError(loc) << "operand '3' must be ConstantInt: "
<< diagMD(node, llvmModule.get());
return false;
isConst = isConstantCI->getValue()[0];
if (baseSymRef)
*baseSymRef = tbaaMapping.lookup(baseMD);
if (accessSymRef)
*accessSymRef = tbaaMapping.lookup(accessMD);
if (offset)
*offset = offsetCI->getZExtValue();
if (isConstant)
*isConstant = isConst;
return true;
// Insert new operations at the end of the MetadataOp.
OpBuilder::InsertionGuard guard(builder);
StringAttr metadataOpName = SymbolTable::getSymbolName(getTBAAMetadataOp());
// On the first walk, create SymbolRefAttr's and map them
// to nodes in `nodesToConvert`.
for (const auto *current : nodesToConvert) {
if (std::optional<StringRef> identity = getIdentityIfRootNode(current)) {
if (identity.value().empty())
return emitError(loc) << "TBAA root node must have non-empty identity: "
<< diagMD(current, llvmModule.get());
// The root nodes do not have operands, so we can create
// the TBAARootMetadataOp on the first walk.
auto rootNode = builder.create<TBAARootMetadataOp>(
loc, getNewTBAANodeName("root"), identity.value());
tbaaMapping.try_emplace(current, FlatSymbolRefAttr::get(rootNode));
if (std::optional<bool> isValid = isTypeDescriptorNode(current)) {
if (!isValid.value())
return failure();
current, FlatSymbolRefAttr::get(builder.getContext(),
if (std::optional<bool> isValid = isTagNode(current)) {
if (!isValid.value())
return failure();
// TBAATagOp symbols must be referred by their fully qualified
// names, so create a path to TBAATagOp symbol.
current, SymbolRefAttr::get(
builder.getContext(), metadataOpName,
return emitError(loc) << "unsupported TBAA node format: "
<< diagMD(current, llvmModule.get());
// On the second walk, create TBAA operations using the symbol names from the
// map.
for (const auto *current : nodesToConvert) {
StringRef identity;
SmallVector<Attribute> memberTypes;
SmallVector<int64_t> memberOffsets;
if (std::optional<bool> isValid = isTypeDescriptorNode(
current, &identity, &memberTypes, &memberOffsets)) {
assert(isValid.value() && "type descriptor node must be valid");
loc, tbaaMapping.lookup(current).getLeafReference(),
builder.getStringAttr(identity), builder.getArrayAttr(memberTypes),
SymbolRefAttr baseSymRef, accessSymRef;
int64_t offset;
bool isConstant;
if (std::optional<bool> isValid = isTagNode(
current, &baseSymRef, &accessSymRef, &offset, &isConstant)) {
assert(isValid.value() && "access tag node must be valid");
loc, tbaaMapping.lookup(current).getLeafReference(),
baseSymRef.getLeafReference(), accessSymRef.getLeafReference(),
offset, isConstant);
return success();
LogicalResult ModuleImport::convertMetadata() {
OpBuilder::InsertionGuard guard(builder);
for (const llvm::Function &func : llvmModule->functions())
for (const llvm::Instruction &inst : llvm::instructions(func)) {
llvm::AAMDNodes nodes = inst.getAAMetadata();
if (!nodes)
if (const llvm::MDNode *tbaaMD = nodes.TBAA)
if (failed(processTBAAMetadata(tbaaMD)))
return failure();
// TODO: only TBAA metadata is currently supported.
return success();
LogicalResult ModuleImport::convertGlobals() {
for (llvm::GlobalVariable &globalVar : llvmModule->globals()) {
if (globalVar.getName() == getGlobalCtorsVarName() ||
globalVar.getName() == getGlobalDtorsVarName()) {
if (failed(convertGlobalCtorsAndDtors(&globalVar))) {
return emitError(mlirModule.getLoc())
<< "unhandled global variable: " << diag(globalVar);
if (failed(convertGlobal(&globalVar))) {
return emitError(mlirModule.getLoc())
<< "unhandled global variable: " << diag(globalVar);
return success();
LogicalResult ModuleImport::convertFunctions() {
for (llvm::Function &func : llvmModule->functions())
if (failed(processFunction(&func)))
return failure();
return success();
void ModuleImport::setNonDebugMetadataAttrs(llvm::Instruction *inst,
Operation *op) {
SmallVector<std::pair<unsigned, llvm::MDNode *>> allMetadata;
for (auto &[kind, node] : allMetadata) {
if (!iface.isConvertibleMetadata(kind))
if (failed(iface.setMetadataAttrs(builder, kind, node, op, *this))) {
Location loc = debugImporter->translateLoc(inst->getDebugLoc());
emitWarning(loc) << "unhandled metadata: "
<< diagMD(node, llvmModule.get()) << " on "
<< diag(*inst);
void ModuleImport::setFastmathFlagsAttr(llvm::Instruction *inst,
Operation *op) const {
auto iface = cast<FastmathFlagsInterface>(op);
// Even if the imported operation implements the fastmath interface, the
// original instruction may not have fastmath flags set. Exit if an
// instruction, such as a non floating-point function call, does not have
// fastmath flags.
if (!isa<llvm::FPMathOperator>(inst))
llvm::FastMathFlags flags = inst->getFastMathFlags();
// Set the fastmath bits flag-by-flag.
FastmathFlags value = {};
value = bitEnumSet(value, FastmathFlags::nnan, flags.noNaNs());
value = bitEnumSet(value, FastmathFlags::ninf, flags.noInfs());
value = bitEnumSet(value, FastmathFlags::nsz, flags.noSignedZeros());
value = bitEnumSet(value, FastmathFlags::arcp, flags.allowReciprocal());
value = bitEnumSet(value, FastmathFlags::contract, flags.allowContract());
value = bitEnumSet(value, FastmathFlags::afn, flags.approxFunc());
value = bitEnumSet(value, FastmathFlags::reassoc, flags.allowReassoc());
FastmathFlagsAttr attr = FastmathFlagsAttr::get(builder.getContext(), value);
iface->setAttr(iface.getFastmathAttrName(), attr);
// We only need integers, floats, doubles, and vectors and tensors thereof for
// attributes. Scalar and vector types are converted to the standard
// equivalents. Array types are converted to ranked tensors; nested array types
// are converted to multi-dimensional tensors or vectors, depending on the
// innermost type being a scalar or a vector.
Type ModuleImport::getStdTypeForAttr(Type type) {
if (!type)
return nullptr;
if (type.isa<IntegerType, FloatType>())
return type;
// LLVM vectors can only contain scalars.
if (LLVM::isCompatibleVectorType(type)) {
llvm::ElementCount numElements = LLVM::getVectorNumElements(type);
if (numElements.isScalable()) {
emitError(UnknownLoc::get(context)) << "scalable vectors not supported";
return nullptr;
Type elementType = getStdTypeForAttr(LLVM::getVectorElementType(type));
if (!elementType)
return nullptr;
return VectorType::get(numElements.getKnownMinValue(), elementType);
// LLVM arrays can contain other arrays or vectors.
if (auto arrayType = type.dyn_cast<LLVMArrayType>()) {
// Recover the nested array shape.
SmallVector<int64_t, 4> shape;
while (arrayType.getElementType().isa<LLVMArrayType>()) {
arrayType = arrayType.getElementType().cast<LLVMArrayType>();
// If the innermost type is a vector, use the multi-dimensional vector as
// attribute type.
if (LLVM::isCompatibleVectorType(arrayType.getElementType())) {
llvm::ElementCount numElements =
if (numElements.isScalable()) {
emitError(UnknownLoc::get(context)) << "scalable vectors not supported";
return nullptr;
Type elementType = getStdTypeForAttr(
if (!elementType)
return nullptr;
return VectorType::get(shape, elementType);
// Otherwise use a tensor.
Type elementType = getStdTypeForAttr(arrayType.getElementType());
if (!elementType)
return nullptr;
return RankedTensorType::get(shape, elementType);
return nullptr;
// Get the given constant as an attribute. Not all constants can be represented
// as attributes.
Attribute ModuleImport::getConstantAsAttr(llvm::Constant *value) {
if (auto *ci = dyn_cast<llvm::ConstantInt>(value))
return builder.getIntegerAttr(
IntegerType::get(context, ci->getType()->getBitWidth()),
if (auto *c = dyn_cast<llvm::ConstantDataArray>(value))
if (c->isString())
return builder.getStringAttr(c->getAsString());
if (auto *c = dyn_cast<llvm::ConstantFP>(value)) {
llvm::Type *type = c->getType();
FloatType floatTy;
if (type->isBFloatTy())
floatTy = FloatType::getBF16(context);
floatTy = getDLFloatType(*context, type->getScalarSizeInBits());
assert(floatTy && "unsupported floating point type");
return builder.getFloatAttr(floatTy, c->getValueAPF());
if (auto *f = dyn_cast<llvm::Function>(value))
return SymbolRefAttr::get(builder.getContext(), f->getName());
// Convert constant data to a dense elements attribute.
if (auto *cd = dyn_cast<llvm::ConstantDataSequential>(value)) {
Type type = convertType(cd->getElementType());
auto attrType = getStdTypeForAttr(convertType(cd->getType()))
if (!attrType)
return nullptr;
if (type.isa<IntegerType>()) {
SmallVector<APInt, 8> values;
for (unsigned i = 0, e = cd->getNumElements(); i < e; ++i)
return DenseElementsAttr::get(attrType, values);
if (type.isa<Float32Type, Float64Type>()) {
SmallVector<APFloat, 8> values;
for (unsigned i = 0, e = cd->getNumElements(); i < e; ++i)
return DenseElementsAttr::get(attrType, values);
return nullptr;
// Unpack constant aggregates to create dense elements attribute whenever
// possible. Return nullptr (failure) otherwise.
if (isa<llvm::ConstantAggregate>(value)) {
auto outerType = getStdTypeForAttr(convertType(value->getType()))
if (!outerType)
return nullptr;
SmallVector<Attribute, 8> values;
SmallVector<int64_t, 8> shape;
for (unsigned i = 0, e = value->getNumOperands(); i < e; ++i) {
auto nested = getConstantAsAttr(value->getAggregateElement(i))
if (!nested)
return nullptr;
return DenseElementsAttr::get(outerType, values);
return nullptr;
LogicalResult ModuleImport::convertGlobal(llvm::GlobalVariable *globalVar) {
// Insert the global after the last one or at the start of the module.
OpBuilder::InsertionGuard guard(builder);
if (!globalInsertionOp)
Attribute valueAttr;
if (globalVar->hasInitializer())
valueAttr = getConstantAsAttr(globalVar->getInitializer());
Type type = convertType(globalVar->getValueType());
uint64_t alignment = 0;
llvm::MaybeAlign maybeAlign = globalVar->getAlign();
if (maybeAlign.has_value()) {
llvm::Align align = *maybeAlign;
alignment = align.value();
GlobalOp globalOp = builder.create<GlobalOp>(
mlirModule.getLoc(), type, globalVar->isConstant(),
convertLinkageFromLLVM(globalVar->getLinkage()), globalVar->getName(),
valueAttr, alignment, /*addr_space=*/globalVar->getAddressSpace(),
globalInsertionOp = globalOp;
if (globalVar->hasInitializer() && !valueAttr) {
Block *block = builder.createBlock(&globalOp.getInitializerRegion());
FailureOr<Value> initializer =
if (failed(initializer))
return failure();
builder.create<ReturnOp>(globalOp.getLoc(), *initializer);
if (globalVar->hasAtLeastLocalUnnamedAddr()) {
if (globalVar->hasSection())
return success();
ModuleImport::convertGlobalCtorsAndDtors(llvm::GlobalVariable *globalVar) {
if (!globalVar->hasInitializer() || !globalVar->hasAppendingLinkage())
return failure();
auto *initializer =
if (!initializer)
return failure();
SmallVector<Attribute> funcs;
SmallVector<int32_t> priorities;
for (llvm::Value *operand : initializer->operands()) {
auto *aggregate = dyn_cast<llvm::ConstantAggregate>(operand);
if (!aggregate || aggregate->getNumOperands() != 3)
return failure();
auto *priority = dyn_cast<llvm::ConstantInt>(aggregate->getOperand(0));
auto *func = dyn_cast<llvm::Function>(aggregate->getOperand(1));
auto *data = dyn_cast<llvm::Constant>(aggregate->getOperand(2));
if (!priority || !func || !data)
return failure();
// GlobalCtorsOps and GlobalDtorsOps do not support non-null data fields.
if (!data->isNullValue())
return failure();
funcs.push_back(FlatSymbolRefAttr::get(context, func->getName()));
OpBuilder::InsertionGuard guard(builder);
if (!globalInsertionOp)
if (globalVar->getName() == getGlobalCtorsVarName()) {
globalInsertionOp = builder.create<LLVM::GlobalCtorsOp>(
mlirModule.getLoc(), builder.getArrayAttr(funcs),
return success();
globalInsertionOp = builder.create<LLVM::GlobalDtorsOp>(
mlirModule.getLoc(), builder.getArrayAttr(funcs),
return success();
SetVector<llvm::Constant *>
ModuleImport::getConstantsToConvert(llvm::Constant *constant) {
// Traverse the constant dependencies in post order.
SmallVector<llvm::Constant *> workList;
SmallVector<llvm::Constant *> orderedList;
while (!workList.empty()) {
llvm::Constant *current = workList.pop_back_val();
// Skip constants that have been converted before and store all other ones.
if (valueMapping.count(current))
// Add the current constant's dependencies to the work list. Only add
// constant dependencies and skip any other values such as basic block
// addresses.
for (llvm::Value *operand : current->operands())
if (auto *constDependency = dyn_cast<llvm::Constant>(operand))
// Use the `getElementValue` method to add the dependencies of zero
// initialized aggregate constants since they do not take any operands.
if (auto *constAgg = dyn_cast<llvm::ConstantAggregateZero>(current)) {
unsigned numElements = constAgg->getElementCount().getFixedValue();
for (unsigned i = 0, e = numElements; i != e; ++i)
// Add the constants in reverse post order to the result set to ensure all
// dependencies are satisfied. Avoid storing duplicates since LLVM constants
// are uniqued and only one `valueMapping` entry per constant is possible.
SetVector<llvm::Constant *> orderedSet;
for (llvm::Constant *orderedConst : llvm::reverse(orderedList))
return orderedSet;
FailureOr<Value> ModuleImport::convertConstant(llvm::Constant *constant) {
Location loc = mlirModule.getLoc();
// Convert constants that can be represented as attributes.
if (Attribute attr = getConstantAsAttr(constant)) {
Type type = convertType(constant->getType());
if (auto symbolRef = attr.dyn_cast<FlatSymbolRefAttr>()) {
return builder.create<AddressOfOp>(loc, type, symbolRef.getValue())
return builder.create<ConstantOp>(loc, type, attr).getResult();
// Convert null pointer constants.
if (auto *nullPtr = dyn_cast<llvm::ConstantPointerNull>(constant)) {
Type type = convertType(nullPtr->getType());
return builder.create<NullOp>(loc, type).getResult();
// Convert undef.
if (auto *undefVal = dyn_cast<llvm::UndefValue>(constant)) {
Type type = convertType(undefVal->getType());
return builder.create<UndefOp>(loc, type).getResult();
// Convert global variable accesses.
if (auto *globalVar = dyn_cast<llvm::GlobalVariable>(constant)) {
Type type = convertType(globalVar->getType());
auto symbolRef = FlatSymbolRefAttr::get(context, globalVar->getName());
return builder.create<AddressOfOp>(loc, type, symbolRef).getResult();
// Convert constant expressions.
if (auto *constExpr = dyn_cast<llvm::ConstantExpr>(constant)) {
// Convert the constant expression to a temporary LLVM instruction and
// translate it using the `processInstruction` method. Delete the
// instruction after the translation and remove it from `valueMapping`,
// since later calls to `getAsInstruction` may return the same address
// resulting in a conflicting `valueMapping` entry.
llvm::Instruction *inst = constExpr->getAsInstruction();
auto guard = llvm::make_scope_exit([&]() {
assert(noResultOpMapping.find(inst) == noResultOpMapping.end() &&
"expected constant expression to return a result");
// Note: `processInstruction` does not call `convertConstant` recursively
// since all constant dependencies have been converted before.
assert(llvm::all_of(inst->operands(), [&](llvm::Value *value) {
return valueMapping.count(value);
if (failed(processInstruction(inst)))
return failure();
return lookupValue(inst);
// Convert aggregate constants.
if (isa<llvm::ConstantAggregate>(constant) ||
isa<llvm::ConstantAggregateZero>(constant)) {
// Lookup the aggregate elements that have been converted before.
SmallVector<Value> elementValues;
if (auto *constAgg = dyn_cast<llvm::ConstantAggregate>(constant)) {
for (llvm::Value *operand : constAgg->operands())
if (auto *constAgg = dyn_cast<llvm::ConstantAggregateZero>(constant)) {
unsigned numElements = constAgg->getElementCount().getFixedValue();
for (unsigned i = 0, e = numElements; i != e; ++i)
assert(llvm::count(elementValues, nullptr) == 0 &&
"expected all elements have been converted before");
// Generate an UndefOp as root value and insert the aggregate elements.
Type rootType = convertType(constant->getType());
bool isArrayOrStruct = rootType.isa<LLVMArrayType, LLVMStructType>();
assert((isArrayOrStruct || LLVM::isCompatibleVectorType(rootType)) &&
"unrecognized aggregate type");
Value root = builder.create<UndefOp>(loc, rootType);
for (const auto &it : llvm::enumerate(elementValues)) {
if (isArrayOrStruct) {
root = builder.create<InsertValueOp>(loc, root, it.value(), it.index());
} else {
Attribute indexAttr = builder.getI32IntegerAttr(it.index());
Value indexValue =
builder.create<ConstantOp>(loc, builder.getI32Type(), indexAttr);
root = builder.create<InsertElementOp>(loc, rootType, root, it.value(),
return root;
return emitError(loc) << "unhandled constant: " << diag(*constant);
FailureOr<Value> ModuleImport::convertConstantExpr(llvm::Constant *constant) {
assert(constantInsertionBlock &&
"expected the constant insertion block to be non-null");
// Insert the constant after the last one or at the start or the entry block.
OpBuilder::InsertionGuard guard(builder);
if (!constantInsertionOp)
// Convert all constants of the expression and add them to `valueMapping`.
SetVector<llvm::Constant *> constantsToConvert =
for (llvm::Constant *constantToConvert : constantsToConvert) {
FailureOr<Value> converted = convertConstant(constantToConvert);
if (failed(converted))
return failure();
mapValue(constantToConvert, *converted);
// Update the constant insertion point and return the converted constant.
Value result = lookupValue(constant);
constantInsertionOp = result.getDefiningOp();
return result;
FailureOr<Value> ModuleImport::convertValue(llvm::Value *value) {
// A value may be wrapped as metadata, for example, when passed to a debug
// intrinsic. Unwrap these values before the conversion.
if (auto *nodeAsVal = dyn_cast<llvm::MetadataAsValue>(value))
if (auto *node = dyn_cast<llvm::ValueAsMetadata>(nodeAsVal->getMetadata()))
value = node->getValue();
// Return the mapped value if it has been converted before.
if (valueMapping.count(value))
return lookupValue(value);
// Convert constants such as immediate values that have no mapping yet.
if (auto *constant = dyn_cast<llvm::Constant>(value))
return convertConstantExpr(constant);
Location loc = mlirModule.getLoc();
if (auto *inst = dyn_cast<llvm::Instruction>(value))
loc = translateLoc(inst->getDebugLoc());
return emitError(loc) << "unhandled value: " << diag(*value);
ModuleImport::convertValues(ArrayRef<llvm::Value *> values) {
SmallVector<Value> remapped;
for (llvm::Value *value : values) {
FailureOr<Value> converted = convertValue(value);
if (failed(converted))
return failure();
return remapped;
IntegerAttr ModuleImport::matchIntegerAttr(llvm::Value *value) {
IntegerAttr integerAttr;
FailureOr<Value> converted = convertValue(value);
bool success = succeeded(converted) &&
matchPattern(*converted, m_Constant(&integerAttr));
assert(success && "expected a constant value");
return integerAttr;
DILocalVariableAttr ModuleImport::matchLocalVariableAttr(llvm::Value *value) {
auto *nodeAsVal = cast<llvm::MetadataAsValue>(value);
auto *node = cast<llvm::DILocalVariable>(nodeAsVal->getMetadata());
return debugImporter->translate(node);
Location ModuleImport::translateLoc(llvm::DILocation *loc) {
return debugImporter->translateLoc(loc);
ModuleImport::convertBranchArgs(llvm::Instruction *branch,
llvm::BasicBlock *target,
SmallVectorImpl<Value> &blockArguments) {
for (auto inst = target->begin(); isa<llvm::PHINode>(inst); ++inst) {
auto *phiInst = cast<llvm::PHINode>(&*inst);
llvm::Value *value = phiInst->getIncomingValueForBlock(branch->getParent());
FailureOr<Value> converted = convertValue(value);
if (failed(converted))
return failure();
return success();
ModuleImport::convertCallTypeAndOperands(llvm::CallBase *callInst,
SmallVectorImpl<Type> &types,
SmallVectorImpl<Value> &operands) {
if (!callInst->getType()->isVoidTy())
if (!callInst->getCalledFunction()) {
FailureOr<Value> called = convertValue(callInst->getCalledOperand());
if (failed(called))
return failure();
SmallVector<llvm::Value *> args(callInst->args());
FailureOr<SmallVector<Value>> arguments = convertValues(args);
if (failed(arguments))
return failure();
llvm::append_range(operands, *arguments);
return success();
LogicalResult ModuleImport::convertIntrinsic(llvm::CallInst *inst) {
if (succeeded(iface.convertIntrinsic(builder, inst, *this)))
return success();
Location loc = translateLoc(inst->getDebugLoc());
return emitError(loc) << "unhandled intrinsic: " << diag(*inst);
LogicalResult ModuleImport::convertInstruction(llvm::Instruction *inst) {
// Convert all instructions that do not provide an MLIR builder.
Location loc = translateLoc(inst->getDebugLoc());
if (inst->getOpcode() == llvm::Instruction::Br) {
auto *brInst = cast<llvm::BranchInst>(inst);
SmallVector<Block *> succBlocks;
SmallVector<SmallVector<Value>> succBlockArgs;
for (auto i : llvm::seq<unsigned>(0, brInst->getNumSuccessors())) {
llvm::BasicBlock *succ = brInst->getSuccessor(i);
SmallVector<Value> blockArgs;
if (failed(convertBranchArgs(brInst, succ, blockArgs)))
return failure();
if (!brInst->isConditional()) {
auto brOp = builder.create<LLVM::BrOp>(loc, succBlockArgs.front(),
mapNoResultOp(inst, brOp);
return success();
FailureOr<Value> condition = convertValue(brInst->getCondition());
if (failed(condition))
return failure();
auto condBrOp = builder.create<LLVM::CondBrOp>(
loc, *condition, succBlocks.front(), succBlockArgs.front(),
succBlocks.back(), succBlockArgs.back());
mapNoResultOp(inst, condBrOp);
return success();
if (inst->getOpcode() == llvm::Instruction::Switch) {
auto *swInst = cast<llvm::SwitchInst>(inst);
// Process the condition value.
FailureOr<Value> condition = convertValue(swInst->getCondition());
if (failed(condition))
return failure();
SmallVector<Value> defaultBlockArgs;
// Process the default case.
llvm::BasicBlock *defaultBB = swInst->getDefaultDest();
if (failed(convertBranchArgs(swInst, defaultBB, defaultBlockArgs)))
return failure();
// Process the cases.
unsigned numCases = swInst->getNumCases();
SmallVector<SmallVector<Value>> caseOperands(numCases);
SmallVector<ValueRange> caseOperandRefs(numCases);
SmallVector<int32_t> caseValues(numCases);
SmallVector<Block *> caseBlocks(numCases);
for (const auto &it : llvm::enumerate(swInst->cases())) {
const llvm::SwitchInst::CaseHandle &caseHandle = it.value();
llvm::BasicBlock *succBB = caseHandle.getCaseSuccessor();
if (failed(convertBranchArgs(swInst, succBB, caseOperands[it.index()])))
return failure();
caseOperandRefs[it.index()] = caseOperands[it.index()];
caseValues[it.index()] = caseHandle.getCaseValue()->getSExtValue();
caseBlocks[it.index()] = lookupBlock(succBB);
auto switchOp = builder.create<SwitchOp>(
loc, *condition, lookupBlock(defaultBB), defaultBlockArgs, caseValues,
caseBlocks, caseOperandRefs);
mapNoResultOp(inst, switchOp);
return success();
if (inst->getOpcode() == llvm::Instruction::PHI) {
Type type = convertType(inst->getType());
mapValue(inst, builder.getInsertionBlock()->addArgument(
type, translateLoc(inst->getDebugLoc())));
return success();
if (inst->getOpcode() == llvm::Instruction::Call) {
auto *callInst = cast<llvm::CallInst>(inst);
SmallVector<Type> types;
SmallVector<Value> operands;
if (failed(convertCallTypeAndOperands(callInst, types, operands)))
return failure();
CallOp callOp;
if (llvm::Function *callee = callInst->getCalledFunction()) {
callOp = builder.create<CallOp>(
loc, types, SymbolRefAttr::get(context, callee->getName()), operands);
} else {
callOp = builder.create<CallOp>(loc, types, operands);
setFastmathFlagsAttr(inst, callOp);
if (!callInst->getType()->isVoidTy())
mapValue(inst, callOp.getResult());
mapNoResultOp(inst, callOp);
return success();
if (inst->getOpcode() == llvm::Instruction::LandingPad) {
auto *lpInst = cast<llvm::LandingPadInst>(inst);
SmallVector<Value> operands;
for (auto i : llvm::seq<unsigned>(0, lpInst->getNumClauses())) {
FailureOr<Value> operand = convertConstantExpr(lpInst->getClause(i));
if (failed(operand))
return failure();
Type type = convertType(lpInst->getType());
auto lpOp =
builder.create<LandingpadOp>(loc, type, lpInst->isCleanup(), operands);
mapValue(inst, lpOp);
return success();
if (inst->getOpcode() == llvm::Instruction::Invoke) {
auto *invokeInst = cast<llvm::InvokeInst>(inst);
SmallVector<Type> types;
SmallVector<Value> operands;
if (failed(convertCallTypeAndOperands(invokeInst, types, operands)))
return failure();
SmallVector<Value> normalArgs, unwindArgs;
(void)convertBranchArgs(invokeInst, invokeInst->getNormalDest(),
(void)convertBranchArgs(invokeInst, invokeInst->getUnwindDest(),
InvokeOp invokeOp;
if (llvm::Function *callee = invokeInst->getCalledFunction()) {
invokeOp = builder.create<InvokeOp>(
loc, types,
SymbolRefAttr::get(builder.getContext(), callee->getName()), operands,
lookupBlock(invokeInst->getNormalDest()), normalArgs,
lookupBlock(invokeInst->getUnwindDest()), unwindArgs);
} else {
invokeOp = builder.create<InvokeOp>(
loc, types, operands, lookupBlock(invokeInst->getNormalDest()),
normalArgs, lookupBlock(invokeInst->getUnwindDest()), unwindArgs);
if (!invokeInst->getType()->isVoidTy())
mapValue(inst, invokeOp.getResults().front());
mapNoResultOp(inst, invokeOp);
return success();
if (inst->getOpcode() == llvm::Instruction::GetElementPtr) {
auto *gepInst = cast<llvm::GetElementPtrInst>(inst);
Type sourceElementType = convertType(gepInst->getSourceElementType());
FailureOr<Value> basePtr = convertValue(gepInst->getOperand(0));
if (failed(basePtr))
return failure();
// Treat every indices as dynamic since GEPOp::build will refine those
// indices into static attributes later. One small downside of this
// approach is that many unused `llvm.mlir.constant` would be emitted
// at first place.
SmallVector<GEPArg> indices;
for (llvm::Value *operand : llvm::drop_begin(gepInst->operand_values())) {
FailureOr<Value> index = convertValue(operand);
if (failed(index))
return failure();
Type type = convertType(inst->getType());
auto gepOp = builder.create<GEPOp>(loc, type, sourceElementType, *basePtr,
indices, gepInst->isInBounds());
mapValue(inst, gepOp);
return success();
// Convert all instructions that have an mlirBuilder.
if (succeeded(convertInstructionImpl(builder, inst, *this)))
return success();
return emitError(loc) << "unhandled instruction: " << diag(*inst);
LogicalResult ModuleImport::processInstruction(llvm::Instruction *inst) {
// FIXME: Support uses of SubtargetData.
// FIXME: Add support for call / operand attributes.
// FIXME: Add support for the indirectbr, cleanupret, catchret, catchswitch,
// callbr, vaarg, landingpad, catchpad, cleanuppad instructions.
// Convert LLVM intrinsics calls to MLIR intrinsics.
if (auto *callInst = dyn_cast<llvm::CallInst>(inst)) {
llvm::Function *callee = callInst->getCalledFunction();
if (callee && callee->isIntrinsic())
return convertIntrinsic(callInst);
// Convert all remaining LLVM instructions to MLIR operations.
return convertInstruction(inst);
FlatSymbolRefAttr ModuleImport::getPersonalityAsAttr(llvm::Function *f) {
if (!f->hasPersonalityFn())
return nullptr;
llvm::Constant *pf = f->getPersonalityFn();
// If it directly has a name, we can use it.
if (pf->hasName())
return SymbolRefAttr::get(builder.getContext(), pf->getName());
// If it doesn't have a name, currently, only function pointers that are
// bitcast to i8* are parsed.
if (auto *ce = dyn_cast<llvm::ConstantExpr>(pf)) {
if (ce->getOpcode() == llvm::Instruction::BitCast &&
ce->getType() == llvm::Type::getInt8PtrTy(f->getContext())) {
if (auto *func = dyn_cast<llvm::Function>(ce->getOperand(0)))
return SymbolRefAttr::get(builder.getContext(), func->getName());
return FlatSymbolRefAttr();
static void processMemoryEffects(llvm::Function *func, LLVMFuncOp funcOp) {
llvm::MemoryEffects memEffects = func->getMemoryEffects();
auto othermem = convertModRefInfoFromLLVM(
auto argMem = convertModRefInfoFromLLVM(
auto inaccessibleMem = convertModRefInfoFromLLVM(
auto memAttr = MemoryEffectsAttr::get(funcOp.getContext(), othermem, argMem,
// Only set the attr when it does not match the default value.
if (memAttr.isReadWrite())
static void processPassthroughAttrs(llvm::Function *func, LLVMFuncOp funcOp) {
MLIRContext *context = funcOp.getContext();
SmallVector<Attribute> passthroughs;
llvm::AttributeSet funcAttrs = func->getAttributes().getAttributes(
for (llvm::Attribute attr : funcAttrs) {
// Skip the memory attribute since the LLVMFuncOp has an explicit memory
// attribute.
if (attr.hasAttribute(llvm::Attribute::Memory))
// Skip invalid type attributes.
if (attr.isTypeAttribute()) {
"type attributes on a function are invalid, skipping it");
StringRef attrName;
if (attr.isStringAttribute())
attrName = attr.getKindAsString();
attrName = llvm::Attribute::getNameFromAttrKind(attr.getKindAsEnum());
auto keyAttr = StringAttr::get(context, attrName);
if (attr.isStringAttribute()) {
StringRef val = attr.getValueAsString();
if (val.empty()) {
ArrayAttr::get(context, {keyAttr, StringAttr::get(context, val)}));
if (attr.isIntAttribute()) {
auto val = std::to_string(attr.getValueAsInt());
ArrayAttr::get(context, {keyAttr, StringAttr::get(context, val)}));
if (attr.isEnumAttribute()) {
llvm_unreachable("unexpected attribute kind");
if (!passthroughs.empty())
funcOp.setPassthroughAttr(ArrayAttr::get(context, passthroughs));
void ModuleImport::processFunctionAttributes(llvm::Function *func,
LLVMFuncOp funcOp) {
processMemoryEffects(func, funcOp);
processPassthroughAttrs(func, funcOp);
LogicalResult ModuleImport::processFunction(llvm::Function *func) {
auto functionType =
if (func->isIntrinsic() &&
return success();
bool dsoLocal = func->hasLocalLinkage();
CConv cconv = convertCConvFromLLVM(func->getCallingConv());
// Insert the function at the end of the module.
OpBuilder::InsertionGuard guard(builder);
builder.setInsertionPoint(mlirModule.getBody(), mlirModule.getBody()->end());
LLVMFuncOp funcOp = builder.create<LLVMFuncOp>(
mlirModule.getLoc(), func->getName(), functionType,
convertLinkageFromLLVM(func->getLinkage()), dsoLocal, cconv);
// Set the function debug information if available.
debugImporter->translate(func, funcOp);
for (const auto &it : llvm::enumerate(functionType.getParams())) {
llvm::SmallVector<NamedAttribute, 1> argAttrs;
if (auto *type = func->getParamByValType(it.index())) {
Type mlirType = convertType(type);
if (auto *type = func->getParamByRefType(it.index())) {
Type mlirType = convertType(type);
if (auto *type = func->getParamStructRetType(it.index())) {
Type mlirType = convertType(type);
if (auto *type = func->getParamInAllocaType(it.index())) {
Type mlirType = convertType(type);
funcOp.setArgAttrs(it.index(), argAttrs);
if (FlatSymbolRefAttr personality = getPersonalityAsAttr(func))
else if (func->hasPersonalityFn())
emitWarning(funcOp.getLoc(), "could not deduce personality, skipping it");
if (func->hasGC())
// Handle Function attributes.
processFunctionAttributes(func, funcOp);
// Convert non-debug metadata by using the dialect interface.
SmallVector<std::pair<unsigned, llvm::MDNode *>> allMetadata;
for (auto &[kind, node] : allMetadata) {
if (!iface.isConvertibleMetadata(kind))
if (failed(iface.setMetadataAttrs(builder, kind, node, funcOp, *this))) {
<< "unhandled function metadata: " << diagMD(node, llvmModule.get())
<< " on " << diag(*func);
if (func->isDeclaration())
return success();
// Eagerly create all blocks.
for (llvm::BasicBlock &bb : *func) {
Block *block =
builder.createBlock(&funcOp.getBody(), funcOp.getBody().end());
mapBlock(&bb, block);
// Add function arguments to the entry block.
for (const auto &it : llvm::enumerate(func->args())) {
BlockArgument blockArg = funcOp.getFunctionBody().addArgument(
functionType.getParamType(it.index()), funcOp.getLoc());
mapValue(&it.value(), blockArg);
// Process the blocks in topological order. The ordered traversal ensures
// operands defined in a dominating block have a valid mapping to an MLIR
// value once a block is translated.
SetVector<llvm::BasicBlock *> blocks = getTopologicallySortedBlocks(func);
for (llvm::BasicBlock *bb : blocks) {
if (failed(processBasicBlock(bb, lookupBlock(bb))))
return failure();
return success();
LogicalResult ModuleImport::processBasicBlock(llvm::BasicBlock *bb,
Block *block) {
for (llvm::Instruction &inst : *bb) {
if (failed(processInstruction(&inst)))
return failure();
// Set the non-debug metadata attributes on the imported operation and emit
// a warning if an instruction other than a phi instruction is dropped
// during the import.
if (Operation *op = lookupOperation(&inst)) {
setNonDebugMetadataAttrs(&inst, op);
} else if (inst.getOpcode() != llvm::Instruction::PHI) {
Location loc = debugImporter->translateLoc(inst.getDebugLoc());
emitWarning(loc) << "dropped instruction: " << diag(inst);
return success();
mlir::translateLLVMIRToModule(std::unique_ptr<llvm::Module> llvmModule,
MLIRContext *context) {
// Preload all registered dialects to allow the import to iterate the
// registered LLVMImportDialectInterface implementations and query the
// supported LLVM IR constructs before starting the translation. Assumes the
// LLVM and DLTI dialects that convert the core LLVM IR constructs have been
// registered before.
OwningOpRef<ModuleOp> module(ModuleOp::create(FileLineColLoc::get(
StringAttr::get(context, llvmModule->getSourceFileName()), /*line=*/0,
DataLayoutSpecInterface dlSpec =
translateDataLayout(llvmModule->getDataLayout(), context);
if (!dlSpec) {
emitError(UnknownLoc::get(context), "can't translate data layout");
return {};
module.get()->setAttr(DLTIDialect::kDataLayoutAttrName, dlSpec);
ModuleImport moduleImport(module.get(), std::move(llvmModule));
if (failed(moduleImport.initializeImportInterface()))
return {};
if (failed(moduleImport.convertMetadata()))
return {};
if (failed(moduleImport.convertGlobals()))
return {};
if (failed(moduleImport.convertFunctions()))
return {};
return module;