Reland "[flang] add option to generate runtime type info as external (#145901) " #146071
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…5901) So far flang generates runtime derived type info global definitions (as opposed to declarations) for all the types used in the current compilation unit even when the derived types are defined in other compilation units. It is using linkonce_odr to achieve derived type descriptor address "uniqueness" aspect needed to match two derived type inside the runtime. This comes at a big compile time cost because of all the extra globals and their definitions in apps with many and complex derived types. This patch adds and experimental option to only generate the rtti definition for the types defined in the current compilation unit and to only generate external declaration for the derived type descriptor object of types defined elsewhere. Note that objects compiled with this option are not compatible with object files compiled without because files compiled without it may drop the rtti for type they defined if it is not used in the compilation unit because of the linkonce_odr aspect. I am adding the option so that we can better measure the extra cost of the current approach on apps and allow speeding up some compilation where devirtualization does not matter (and the build config links to all module file object anyway).
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@llvm/pr-subscribers-flang-fir-hlfir @llvm/pr-subscribers-flang-codegen Author: None (jeanPerier) ChangesReland #145901 with a fix for shared library builds (see second commit). Lowering cannot directly use cl::opts from lib/Optimizer/Passes/CommandLineOpts.cpp without linking against Instead of adding the linking dependency, I think it is cleaner to use a proper lowering options and let the driver read the cl::opt (I would rather keep the option a cl::opt before doing a bit more testing and making it a proper driver option). Patch is 48.11 KiB, truncated to 20.00 KiB below, full version: https://github.com/llvm/llvm-project/pull/146071.diff 18 Files Affected:
diff --git a/flang/include/flang/Evaluate/tools.h b/flang/include/flang/Evaluate/tools.h
index d26a477ddded1..cad1b634f8924 100644
--- a/flang/include/flang/Evaluate/tools.h
+++ b/flang/include/flang/Evaluate/tools.h
@@ -1585,6 +1585,7 @@ bool IsExtensibleType(const DerivedTypeSpec *);
bool IsSequenceOrBindCType(const DerivedTypeSpec *);
bool IsBuiltinDerivedType(const DerivedTypeSpec *derived, const char *name);
bool IsBuiltinCPtr(const Symbol &);
+bool IsFromBuiltinModule(const Symbol &);
bool IsEventType(const DerivedTypeSpec *);
bool IsLockType(const DerivedTypeSpec *);
bool IsNotifyType(const DerivedTypeSpec *);
diff --git a/flang/include/flang/Lower/LoweringOptions.def b/flang/include/flang/Lower/LoweringOptions.def
index d97abf4d864b8..3263ab129d076 100644
--- a/flang/include/flang/Lower/LoweringOptions.def
+++ b/flang/include/flang/Lower/LoweringOptions.def
@@ -66,5 +66,9 @@ ENUM_LOWERINGOPT(RepackArraysWhole, unsigned, 1, 0)
/// If true, CUDA Fortran runtime check is inserted.
ENUM_LOWERINGOPT(CUDARuntimeCheck, unsigned, 1, 0)
+/// If true, do not generate definition for runtime type info global objects of
+/// derived types defined in other compilation units.
+ENUM_LOWERINGOPT(SkipExternalRttiDefinition, unsigned, 1, 0)
+
#undef LOWERINGOPT
#undef ENUM_LOWERINGOPT
diff --git a/flang/include/flang/Optimizer/CodeGen/CodeGen.h b/flang/include/flang/Optimizer/CodeGen/CodeGen.h
index 0398d0f248e08..93f07d8d5d4d9 100644
--- a/flang/include/flang/Optimizer/CodeGen/CodeGen.h
+++ b/flang/include/flang/Optimizer/CodeGen/CodeGen.h
@@ -39,6 +39,9 @@ struct FIRToLLVMPassOptions {
// that such programs would crash at runtime if the derived type descriptors
// are required by the runtime, so this is only an option to help debugging.
bool ignoreMissingTypeDescriptors = false;
+ // Similar to ignoreMissingTypeDescriptors, but generate external declaration
+ // for the missing type descriptor globals instead.
+ bool skipExternalRttiDefinition = false;
// Generate TBAA information for FIR types and memory accessing operations.
bool applyTBAA = false;
diff --git a/flang/include/flang/Optimizer/Passes/CommandLineOpts.h b/flang/include/flang/Optimizer/Passes/CommandLineOpts.h
index 1cfaf285e75e6..76ac9d0622d2b 100644
--- a/flang/include/flang/Optimizer/Passes/CommandLineOpts.h
+++ b/flang/include/flang/Optimizer/Passes/CommandLineOpts.h
@@ -32,6 +32,19 @@ extern llvm::cl::opt<std::size_t> arrayStackAllocationThreshold;
/// generated by the frontend.
extern llvm::cl::opt<bool> ignoreMissingTypeDescriptors;
+/// Shared option in tools to only generate rtti static object definitions for
+/// derived types defined in the current compilation unit. Derived type
+/// descriptor object for types defined in other objects will only be declared
+/// as external. This also changes the linkage of rtti objects defined in the
+/// current compilation unit from linkonce_odr to external so that unused rtti
+/// objects are retained and can be accessed from other compilation units. This
+/// is an experimental option to explore compilation speed improvements and is
+/// an ABI breaking change because of the linkage change.
+/// It will also require linking against module file objects of modules defining
+/// only types (even for trivial types without type bound procedures, which
+/// differs from most compilers).
+extern llvm::cl::opt<bool> skipExternalRttiDefinition;
+
/// Default optimization level used to create Flang pass pipeline is O0.
extern llvm::OptimizationLevel defaultOptLevel;
diff --git a/flang/include/flang/Optimizer/Support/Utils.h b/flang/include/flang/Optimizer/Support/Utils.h
index ec73af6ec72e9..83c936b7dcada 100644
--- a/flang/include/flang/Optimizer/Support/Utils.h
+++ b/flang/include/flang/Optimizer/Support/Utils.h
@@ -35,32 +35,6 @@ inline std::int64_t toInt(mlir::arith::ConstantOp cop) {
.getSExtValue();
}
-// Reconstruct binding tables for dynamic dispatch.
-using BindingTable = llvm::DenseMap<llvm::StringRef, unsigned>;
-using BindingTables = llvm::DenseMap<llvm::StringRef, BindingTable>;
-
-inline void buildBindingTables(BindingTables &bindingTables,
- mlir::ModuleOp mod) {
-
- // The binding tables are defined in FIR after lowering inside fir.type_info
- // operations. Go through each binding tables and store the procedure name and
- // binding index for later use by the fir.dispatch conversion pattern.
- for (auto typeInfo : mod.getOps<fir::TypeInfoOp>()) {
- unsigned bindingIdx = 0;
- BindingTable bindings;
- if (typeInfo.getDispatchTable().empty()) {
- bindingTables[typeInfo.getSymName()] = bindings;
- continue;
- }
- for (auto dtEntry :
- typeInfo.getDispatchTable().front().getOps<fir::DTEntryOp>()) {
- bindings[dtEntry.getMethod()] = bindingIdx;
- ++bindingIdx;
- }
- bindingTables[typeInfo.getSymName()] = bindings;
- }
-}
-
// Translate front-end KINDs for use in the IR and code gen.
inline std::vector<fir::KindTy>
fromDefaultKinds(const Fortran::common::IntrinsicTypeDefaultKinds &defKinds) {
diff --git a/flang/include/flang/Semantics/runtime-type-info.h b/flang/include/flang/Semantics/runtime-type-info.h
index e90d3ae8baf1e..6c5a061d1c1a2 100644
--- a/flang/include/flang/Semantics/runtime-type-info.h
+++ b/flang/include/flang/Semantics/runtime-type-info.h
@@ -38,6 +38,10 @@ RuntimeDerivedTypeTables BuildRuntimeDerivedTypeTables(SemanticsContext &);
/// to describe other derived types at runtime in flang descriptor.
constexpr char typeInfoBuiltinModule[]{"__fortran_type_info"};
+/// Name of the builtin derived type in __fortran_type_inf that is used for
+/// derived type descriptors.
+constexpr char typeDescriptorTypeName[]{"derivedtype"};
+
/// Name of the bindings descriptor component in the DerivedType type of the
/// __Fortran_type_info module
constexpr char bindingDescCompName[]{"binding"};
diff --git a/flang/lib/Evaluate/tools.cpp b/flang/lib/Evaluate/tools.cpp
index 68838564f87ba..fcacdb93d662b 100644
--- a/flang/lib/Evaluate/tools.cpp
+++ b/flang/lib/Evaluate/tools.cpp
@@ -2334,6 +2334,11 @@ bool IsBuiltinCPtr(const Symbol &symbol) {
return false;
}
+bool IsFromBuiltinModule(const Symbol &symbol) {
+ const Scope &scope{symbol.GetUltimate().owner()};
+ return IsSameModule(&scope, scope.context().GetBuiltinsScope());
+}
+
bool IsIsoCType(const DerivedTypeSpec *derived) {
return IsBuiltinDerivedType(derived, "c_ptr") ||
IsBuiltinDerivedType(derived, "c_funptr");
diff --git a/flang/lib/Frontend/CompilerInvocation.cpp b/flang/lib/Frontend/CompilerInvocation.cpp
index 766131fd69d85..30d81f3daa969 100644
--- a/flang/lib/Frontend/CompilerInvocation.cpp
+++ b/flang/lib/Frontend/CompilerInvocation.cpp
@@ -14,6 +14,7 @@
#include "flang/Frontend/CodeGenOptions.h"
#include "flang/Frontend/PreprocessorOptions.h"
#include "flang/Frontend/TargetOptions.h"
+#include "flang/Optimizer/Passes/CommandLineOpts.h"
#include "flang/Semantics/semantics.h"
#include "flang/Support/Fortran-features.h"
#include "flang/Support/OpenMP-features.h"
@@ -1792,6 +1793,7 @@ void CompilerInvocation::setLoweringOptions() {
// Lower TRANSPOSE as a runtime call under -O0.
loweringOpts.setOptimizeTranspose(codegenOpts.OptimizationLevel > 0);
loweringOpts.setUnderscoring(codegenOpts.Underscoring);
+ loweringOpts.setSkipExternalRttiDefinition(skipExternalRttiDefinition);
const Fortran::common::LangOptions &langOptions = getLangOpts();
loweringOpts.setIntegerWrapAround(langOptions.getSignedOverflowBehavior() ==
diff --git a/flang/lib/Lower/Bridge.cpp b/flang/lib/Lower/Bridge.cpp
index 7b640dd497af3..ff35840a6668c 100644
--- a/flang/lib/Lower/Bridge.cpp
+++ b/flang/lib/Lower/Bridge.cpp
@@ -262,6 +262,7 @@ class TypeInfoConverter {
}
void createTypeInfo(Fortran::lower::AbstractConverter &converter) {
+ createTypeInfoForTypeDescriptorBuiltinType(converter);
while (!registeredTypeInfoA.empty()) {
currentTypeInfoStack = ®isteredTypeInfoB;
for (const TypeInfo &info : registeredTypeInfoA)
@@ -277,10 +278,22 @@ class TypeInfoConverter {
private:
void createTypeInfoOpAndGlobal(Fortran::lower::AbstractConverter &converter,
const TypeInfo &info) {
- Fortran::lower::createRuntimeTypeInfoGlobal(converter, info.symbol.get());
+ if (!converter.getLoweringOptions().getSkipExternalRttiDefinition())
+ Fortran::lower::createRuntimeTypeInfoGlobal(converter, info.symbol.get());
createTypeInfoOp(converter, info);
}
+ void createTypeInfoForTypeDescriptorBuiltinType(
+ Fortran::lower::AbstractConverter &converter) {
+ if (registeredTypeInfoA.empty())
+ return;
+ auto builtinTypeInfoType = llvm::cast<fir::RecordType>(
+ converter.genType(registeredTypeInfoA[0].symbol.get()));
+ converter.getFirOpBuilder().createTypeInfoOp(
+ registeredTypeInfoA[0].loc, builtinTypeInfoType,
+ /*parentType=*/fir::RecordType{});
+ }
+
void createTypeInfoOp(Fortran::lower::AbstractConverter &converter,
const TypeInfo &info) {
fir::RecordType parentType{};
diff --git a/flang/lib/Lower/ConvertVariable.cpp b/flang/lib/Lower/ConvertVariable.cpp
index 49e6ea02d51a7..7ab3c43016bd9 100644
--- a/flang/lib/Lower/ConvertVariable.cpp
+++ b/flang/lib/Lower/ConvertVariable.cpp
@@ -647,13 +647,19 @@ fir::GlobalOp Fortran::lower::defineGlobal(
/// Return linkage attribute for \p var.
static mlir::StringAttr
-getLinkageAttribute(fir::FirOpBuilder &builder,
+getLinkageAttribute(Fortran::lower::AbstractConverter &converter,
const Fortran::lower::pft::Variable &var) {
+ fir::FirOpBuilder &builder = converter.getFirOpBuilder();
// Runtime type info for a same derived type is identical in each compilation
// unit. It desired to avoid having to link against module that only define a
// type. Therefore the runtime type info is generated everywhere it is needed
- // with `linkonce_odr` LLVM linkage.
- if (var.isRuntimeTypeInfoData())
+ // with `linkonce_odr` LLVM linkage (unless the skipExternalRttiDefinition
+ // option is set, in which case one will need to link against objects of
+ // modules defining types). Builtin objects rtti is always generated because
+ // the builtin module is currently not compiled or part of the runtime.
+ if (var.isRuntimeTypeInfoData() &&
+ (!converter.getLoweringOptions().getSkipExternalRttiDefinition() ||
+ Fortran::semantics::IsFromBuiltinModule(var.getSymbol())))
return builder.createLinkOnceODRLinkage();
if (var.isModuleOrSubmoduleVariable())
return {}; // external linkage
@@ -673,7 +679,7 @@ static void instantiateGlobal(Fortran::lower::AbstractConverter &converter,
fir::FirOpBuilder &builder = converter.getFirOpBuilder();
std::string globalName = converter.mangleName(sym);
mlir::Location loc = genLocation(converter, sym);
- mlir::StringAttr linkage = getLinkageAttribute(builder, var);
+ mlir::StringAttr linkage = getLinkageAttribute(converter, var);
fir::GlobalOp global;
if (var.isModuleOrSubmoduleVariable()) {
// A non-intrinsic module global is defined when lowering the module.
@@ -1265,7 +1271,7 @@ instantiateAggregateStore(Fortran::lower::AbstractConverter &converter,
if (var.isGlobal()) {
fir::GlobalOp global;
auto &aggregate = var.getAggregateStore();
- mlir::StringAttr linkage = getLinkageAttribute(builder, var);
+ mlir::StringAttr linkage = getLinkageAttribute(converter, var);
if (var.isModuleOrSubmoduleVariable()) {
// A module global was or will be defined when lowering the module. Emit
// only a declaration if the global does not exist at that point.
@@ -2470,8 +2476,7 @@ void Fortran::lower::defineModuleVariable(
AbstractConverter &converter, const Fortran::lower::pft::Variable &var) {
// Use empty linkage for module variables, which makes them available
// for use in another unit.
- mlir::StringAttr linkage =
- getLinkageAttribute(converter.getFirOpBuilder(), var);
+ mlir::StringAttr linkage = getLinkageAttribute(converter, var);
if (!var.isGlobal())
fir::emitFatalError(converter.getCurrentLocation(),
"attempting to lower module variable as local");
@@ -2606,10 +2611,9 @@ void Fortran::lower::createIntrinsicModuleGlobal(
void Fortran::lower::createRuntimeTypeInfoGlobal(
Fortran::lower::AbstractConverter &converter,
const Fortran::semantics::Symbol &typeInfoSym) {
- fir::FirOpBuilder &builder = converter.getFirOpBuilder();
std::string globalName = converter.mangleName(typeInfoSym);
auto var = Fortran::lower::pft::Variable(typeInfoSym, /*global=*/true);
- mlir::StringAttr linkage = getLinkageAttribute(builder, var);
+ mlir::StringAttr linkage = getLinkageAttribute(converter, var);
defineGlobal(converter, var, globalName, linkage);
}
diff --git a/flang/lib/Optimizer/CodeGen/CodeGen.cpp b/flang/lib/Optimizer/CodeGen/CodeGen.cpp
index a3de3ae9d116a..2b018912b40e4 100644
--- a/flang/lib/Optimizer/CodeGen/CodeGen.cpp
+++ b/flang/lib/Optimizer/CodeGen/CodeGen.cpp
@@ -1294,6 +1294,51 @@ genCUFAllocDescriptor(mlir::Location loc,
.getResult();
}
+/// Get the address of the type descriptor global variable that was created by
+/// lowering for derived type \p recType.
+template <typename ModOpTy>
+static mlir::Value
+getTypeDescriptor(ModOpTy mod, mlir::ConversionPatternRewriter &rewriter,
+ mlir::Location loc, fir::RecordType recType,
+ const fir::FIRToLLVMPassOptions &options) {
+ std::string name =
+ options.typeDescriptorsRenamedForAssembly
+ ? fir::NameUniquer::getTypeDescriptorAssemblyName(recType.getName())
+ : fir::NameUniquer::getTypeDescriptorName(recType.getName());
+ mlir::Type llvmPtrTy = ::getLlvmPtrType(mod.getContext());
+ if (auto global = mod.template lookupSymbol<fir::GlobalOp>(name))
+ return rewriter.create<mlir::LLVM::AddressOfOp>(loc, llvmPtrTy,
+ global.getSymName());
+ // The global may have already been translated to LLVM.
+ if (auto global = mod.template lookupSymbol<mlir::LLVM::GlobalOp>(name))
+ return rewriter.create<mlir::LLVM::AddressOfOp>(loc, llvmPtrTy,
+ global.getSymName());
+ // Type info derived types do not have type descriptors since they are the
+ // types defining type descriptors.
+ if (options.ignoreMissingTypeDescriptors ||
+ fir::NameUniquer::belongsToModule(
+ name, Fortran::semantics::typeInfoBuiltinModule))
+ return rewriter.create<mlir::LLVM::ZeroOp>(loc, llvmPtrTy);
+
+ if (!options.skipExternalRttiDefinition)
+ fir::emitFatalError(loc,
+ "runtime derived type info descriptor was not "
+ "generated and skipExternalRttiDefinition and "
+ "ignoreMissingTypeDescriptors options are not set");
+
+ // Rtti for a derived type defined in another compilation unit and for which
+ // rtti was not defined in lowering because of the skipExternalRttiDefinition
+ // option. Generate the object declaration now.
+ auto insertPt = rewriter.saveInsertionPoint();
+ rewriter.setInsertionPoint(mod.getBody(), mod.getBody()->end());
+ mlir::LLVM::GlobalOp global = rewriter.create<mlir::LLVM::GlobalOp>(
+ loc, llvmPtrTy, /*constant=*/true, mlir::LLVM::Linkage::External, name,
+ mlir::Attribute());
+ rewriter.restoreInsertionPoint(insertPt);
+ return rewriter.create<mlir::LLVM::AddressOfOp>(loc, llvmPtrTy,
+ global.getSymName());
+}
+
/// Common base class for embox to descriptor conversion.
template <typename OP>
struct EmboxCommonConversion : public fir::FIROpConversion<OP> {
@@ -1406,36 +1451,6 @@ struct EmboxCommonConversion : public fir::FIROpConversion<OP> {
stride);
}
- /// Get the address of the type descriptor global variable that was created by
- /// lowering for derived type \p recType.
- template <typename ModOpTy>
- mlir::Value
- getTypeDescriptor(ModOpTy mod, mlir::ConversionPatternRewriter &rewriter,
- mlir::Location loc, fir::RecordType recType) const {
- std::string name =
- this->options.typeDescriptorsRenamedForAssembly
- ? fir::NameUniquer::getTypeDescriptorAssemblyName(recType.getName())
- : fir::NameUniquer::getTypeDescriptorName(recType.getName());
- mlir::Type llvmPtrTy = ::getLlvmPtrType(mod.getContext());
- if (auto global = mod.template lookupSymbol<fir::GlobalOp>(name)) {
- return rewriter.create<mlir::LLVM::AddressOfOp>(loc, llvmPtrTy,
- global.getSymName());
- }
- if (auto global = mod.template lookupSymbol<mlir::LLVM::GlobalOp>(name)) {
- // The global may have already been translated to LLVM.
- return rewriter.create<mlir::LLVM::AddressOfOp>(loc, llvmPtrTy,
- global.getSymName());
- }
- // Type info derived types do not have type descriptors since they are the
- // types defining type descriptors.
- if (!this->options.ignoreMissingTypeDescriptors &&
- !fir::NameUniquer::belongsToModule(
- name, Fortran::semantics::typeInfoBuiltinModule))
- fir::emitFatalError(
- loc, "runtime derived type info descriptor was not generated");
- return rewriter.create<mlir::LLVM::ZeroOp>(loc, llvmPtrTy);
- }
-
template <typename ModOpTy>
mlir::Value populateDescriptor(mlir::Location loc, ModOpTy mod,
fir::BaseBoxType boxTy, mlir::Type inputType,
@@ -1500,7 +1515,8 @@ struct EmboxCommonConversion : public fir::FIROpConversion<OP> {
mlir::Type innerType = fir::unwrapInnerType(inputType);
if (innerType && mlir::isa<fir::RecordType>(innerType)) {
auto recTy = mlir::dyn_cast<fir::RecordType>(innerType);
- typeDesc = getTypeDescriptor(mod, rewriter, loc, recTy);
+ typeDesc =
+ getTypeDescriptor(mod, rewriter, loc, recTy, this->options);
} else {
// Unlimited polymorphic type descriptor with no record type. Set
// type descriptor address to a clean state.
@@ -1508,8 +1524,8 @@ struct EmboxCommonConversion : public fir::FIROpConversion<OP> {
loc, ::getLlvmPtrType(mod.getContext()));
}
} else {
- typeDesc = getTypeDescriptor(mod, rewriter, loc,
- fir::unwrapIfDerived(boxTy));
+ typeDesc = getTypeDescriptor(
+ mod, rewriter, loc, fir::unwrapIfDerived(boxTy), this->options);
}
}
if (typeDesc)
@@ -3021,22 +3037,10 @@ struct TypeDescOpConversion : public fir::FIROpConversion<fir::TypeDescOp> {
assert(mlir::isa<fir::RecordType>(inTy) && "expecting fir.type");
auto recordType = mlir::dyn_cast<fir::RecordType>(inTy);
auto module = typeDescOp.getOperation()->getParentOfType<mlir::ModuleOp>();
- std::string typeDescName =
- this->options.typeDescriptorsRenamedForAssembly
- ? fir::NameUniquer::getTypeDescriptorAssemblyName(
- recordType.getName())
- : fir::NameUniquer::getTypeDescriptorName(recordType.getName());
- auto llvmPtrTy = ::getLlvmPtrType(typeDescOp.getContext());
- if (auto global = module.lookupSymbol<mlir::LLVM::GlobalOp>(typeDescName)) {
- rewriter.replaceOpWithNewOp<mlir::LLVM::AddressOfOp>(
- typeDescOp, llvmPtrTy, global.getSymName());
- return mlir::success();
- } else if (auto global = module.lookupSymbol<fir::GlobalOp>(typeDescName)) {
- rewriter.replaceOpWithNewOp<mlir::LLVM::AddressOfOp>(
- typeDescOp, llvmPtrTy, global.getSymName());
- return mlir::success();
- }
- return mlir::failure();
+ mlir::Value typeDesc = getTypeDescriptor(
+ module, rewriter, typeDescOp.getLoc(), recordType, this->options);
+ rewriter.replaceOp(typeDescOp, typeDesc);
+ return mlir::success();
}
};
diff --git a/flang/lib/Optimizer/Passes/CommandLineOpts.cpp b/flang/lib/Optimizer/Passes/CommandLineOpts.cpp
index f95a280883cba..014237542f24d 100644
--- a/flang/lib/Optimizer/Passes/Co...
[truncated]
|
vzakhari
approved these changes
Jun 27, 2025
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Reland #145901 with a fix for shared library builds (see second commit).
Lowering cannot directly use cl::opts from lib/Optimizer/Passes/CommandLineOpts.cpp without linking against
flangPasses.Instead of adding the linking dependency, I think it is cleaner to use a proper lowering options and let the driver read the cl::opt (I would rather keep the option a cl::opt before doing a bit more testing and making it a proper driver option).