[Mlir-commits] [mlir] [MLIR][LLVMIR] Import: add flag to prefer using unregistered intrinsics (PR #130685)
Bruno Cardoso Lopes
llvmlistbot at llvm.org
Fri Mar 14 11:32:07 PDT 2025
https://github.com/bcardosolopes updated https://github.com/llvm/llvm-project/pull/130685
>From 8ebcad4bbda33b7598f5c8b1d9be667d4d2e2fbf Mon Sep 17 00:00:00 2001
From: Bruno Cardoso Lopes <bruno.cardoso at gmail.com>
Date: Mon, 10 Mar 2025 14:26:05 -0700
Subject: [PATCH 1/3] [MLIR][LLVMIR] Import: add flag to prefer using
unregistered intrinsics
Currently, there is no common mechanism for supported intrinsics to be
generically annotated with arg and ret attributes. Since there are many
supported intrinsics around different dialects, the amount of work to teach
all them about these attributes is not trivial.
This PR adds a new flag `-prefer-unregistered-intrinsics` that can be used
alongside `--import-llvm` to always use `llvm.intrinsic_call` during import
time (ignoring dialect hooks for custom intrinsic support).
Using this flag allow us to roundtrip the LLVM IR while eliminating a whole set
of differences coming from lack of arg/ret attributes on supported intrinsics.
Note `convertIntrinsic` has to be moved to an implementation file because it
queries into `moduleImport` state, which is a fwd declaration in
`LLVMImportInterface.h`
---
mlir/include/mlir/Target/LLVMIR/Import.h | 12 ++++----
.../mlir/Target/LLVMIR/LLVMImportInterface.h | 21 +-------------
.../include/mlir/Target/LLVMIR/ModuleImport.h | 13 ++++++++-
mlir/lib/Target/LLVMIR/ConvertFromLLVMIR.cpp | 14 ++++++++--
.../lib/Target/LLVMIR/LLVMImportInterface.cpp | 28 +++++++++++++++++++
mlir/lib/Target/LLVMIR/ModuleImport.cpp | 18 ++++++------
.../Import/intrinsic-prefer-unregistered.ll | 10 +++++++
7 files changed, 79 insertions(+), 37 deletions(-)
create mode 100644 mlir/test/Target/LLVMIR/Import/intrinsic-prefer-unregistered.ll
diff --git a/mlir/include/mlir/Target/LLVMIR/Import.h b/mlir/include/mlir/Target/LLVMIR/Import.h
index 4aa8f2ab7d8ce..2fef44947b6c2 100644
--- a/mlir/include/mlir/Target/LLVMIR/Import.h
+++ b/mlir/include/mlir/Target/LLVMIR/Import.h
@@ -41,11 +41,13 @@ class ModuleOp;
/// adversarial inputs.
/// The `loadAllDialects` flag (default on) will load all dialects in the
/// context.
-OwningOpRef<ModuleOp>
-translateLLVMIRToModule(std::unique_ptr<llvm::Module> llvmModule,
- MLIRContext *context, bool emitExpensiveWarnings = true,
- bool dropDICompositeTypeElements = false,
- bool loadAllDialects = true);
+/// The `preferUnregisteredIntrinsics` flag (default off) controls whether to
+/// prefer generic version of imported intrinsics with `llvm.intrinsic_call`
+/// than using versions supported by a dialects.
+OwningOpRef<ModuleOp> translateLLVMIRToModule(
+ std::unique_ptr<llvm::Module> llvmModule, MLIRContext *context,
+ bool emitExpensiveWarnings = true, bool dropDICompositeTypeElements = false,
+ bool loadAllDialects = true, bool preferUnregisteredIntrinsics = false);
/// Translate the given LLVM data layout into an MLIR equivalent using the DLTI
/// dialect.
diff --git a/mlir/include/mlir/Target/LLVMIR/LLVMImportInterface.h b/mlir/include/mlir/Target/LLVMIR/LLVMImportInterface.h
index 686969f891f20..6a42627e17e60 100644
--- a/mlir/include/mlir/Target/LLVMIR/LLVMImportInterface.h
+++ b/mlir/include/mlir/Target/LLVMIR/LLVMImportInterface.h
@@ -153,26 +153,7 @@ class LLVMImportInterface
/// Converts the LLVM intrinsic to an MLIR operation if a conversion exists.
/// Returns failure otherwise.
LogicalResult convertIntrinsic(OpBuilder &builder, llvm::CallInst *inst,
- LLVM::ModuleImport &moduleImport) const {
- // Lookup the dialect interface for the given intrinsic.
- // Verify the intrinsic identifier maps to an actual intrinsic.
- llvm::Intrinsic::ID intrinId = inst->getIntrinsicID();
- assert(intrinId != llvm::Intrinsic::not_intrinsic);
-
- // First lookup the intrinsic across different dialects for known
- // supported conversions, examples include arm-neon, nvm-sve, etc.
- Dialect *dialect = intrinsicToDialect.lookup(intrinId);
-
- // No specialized (supported) intrinsics, attempt to generate a generic
- // version via llvm.call_intrinsic (if available).
- if (!dialect)
- return convertUnregisteredIntrinsic(builder, inst, moduleImport);
-
- // Dispatch the conversion to the dialect interface.
- const LLVMImportDialectInterface *iface = getInterfaceFor(dialect);
- assert(iface && "expected to find a dialect interface");
- return iface->convertIntrinsic(builder, inst, moduleImport);
- }
+ LLVM::ModuleImport &moduleImport) const;
/// Returns true if the given LLVM IR intrinsic is convertible to an MLIR
/// operation.
diff --git a/mlir/include/mlir/Target/LLVMIR/ModuleImport.h b/mlir/include/mlir/Target/LLVMIR/ModuleImport.h
index a4d108e349c00..a69b8e75e6ef9 100644
--- a/mlir/include/mlir/Target/LLVMIR/ModuleImport.h
+++ b/mlir/include/mlir/Target/LLVMIR/ModuleImport.h
@@ -47,7 +47,8 @@ class LoopAnnotationImporter;
class ModuleImport {
public:
ModuleImport(ModuleOp mlirModule, std::unique_ptr<llvm::Module> llvmModule,
- bool emitExpensiveWarnings, bool importEmptyDICompositeTypes);
+ bool emitExpensiveWarnings, bool importEmptyDICompositeTypes,
+ bool preferUnregisteredIntrinsics);
/// Calls the LLVMImportInterface initialization that queries the registered
/// dialect interfaces for the supported LLVM IR intrinsics and metadata kinds
@@ -284,6 +285,12 @@ class ModuleImport {
void convertParameterAttributes(llvm::CallBase *call, ArrayAttr &argsAttr,
ArrayAttr &resAttr, OpBuilder &builder);
+ /// Whether the importer should try to convert all intrinsics to
+ /// llvm.call_intrinsic instead of dialect supported operations.
+ bool useUnregisteredIntrinsicsOnly() const {
+ return preferUnregisteredIntrinsics;
+ }
+
private:
/// Clears the accumulated state before processing a new region.
void clearRegionState() {
@@ -481,6 +488,10 @@ class ModuleImport {
/// emitted. Avoids generating warnings for unhandled debug intrinsics and
/// metadata that otherwise dominate the translation time for large inputs.
bool emitExpensiveWarnings;
+
+ /// An option to control whether to disable supported intrinsic support in
+ /// favor a more generic version via `llvm.intrinsic_call`.
+ bool preferUnregisteredIntrinsics;
};
} // namespace LLVM
diff --git a/mlir/lib/Target/LLVMIR/ConvertFromLLVMIR.cpp b/mlir/lib/Target/LLVMIR/ConvertFromLLVMIR.cpp
index 0784c3c95e47e..b10fdd6f37f79 100644
--- a/mlir/lib/Target/LLVMIR/ConvertFromLLVMIR.cpp
+++ b/mlir/lib/Target/LLVMIR/ConvertFromLLVMIR.cpp
@@ -37,6 +37,13 @@ void registerFromLLVMIRTranslation() {
"the LLVM IR import (discouraged: testing only!)"),
llvm::cl::init(false));
+ static llvm::cl::opt<bool> preferUnregisteredIntrinsics(
+ "prefer-unregistered-intrinsics",
+ llvm::cl::desc(
+ "Prefer translation all intrinsics into llvm.call_intrinsic instead "
+ "of using dialect supported intrinsics"),
+ llvm::cl::init(false));
+
TranslateToMLIRRegistration registration(
"import-llvm", "Translate LLVMIR to MLIR",
[](llvm::SourceMgr &sourceMgr,
@@ -60,9 +67,10 @@ void registerFromLLVMIRTranslation() {
if (llvmModule->IsNewDbgInfoFormat)
llvmModule->convertFromNewDbgValues();
- return translateLLVMIRToModule(std::move(llvmModule), context,
- emitExpensiveWarnings,
- dropDICompositeTypeElements);
+ return translateLLVMIRToModule(
+ std::move(llvmModule), context, emitExpensiveWarnings,
+ dropDICompositeTypeElements, /*loadAllDialects=*/true,
+ preferUnregisteredIntrinsics);
},
[](DialectRegistry ®istry) {
// Register the DLTI dialect used to express the data layout
diff --git a/mlir/lib/Target/LLVMIR/LLVMImportInterface.cpp b/mlir/lib/Target/LLVMIR/LLVMImportInterface.cpp
index fbf2d709c240c..2d7257a2d9698 100644
--- a/mlir/lib/Target/LLVMIR/LLVMImportInterface.cpp
+++ b/mlir/lib/Target/LLVMIR/LLVMImportInterface.cpp
@@ -62,3 +62,31 @@ LogicalResult mlir::LLVMImportInterface::convertUnregisteredIntrinsic(
return success();
}
+
+/// Converts the LLVM intrinsic to an MLIR operation if a conversion exists.
+/// Returns failure otherwise.
+LogicalResult mlir::LLVMImportInterface::convertIntrinsic(
+ OpBuilder &builder, llvm::CallInst *inst,
+ LLVM::ModuleImport &moduleImport) const {
+ // Lookup the dialect interface for the given intrinsic.
+ // Verify the intrinsic identifier maps to an actual intrinsic.
+ llvm::Intrinsic::ID intrinId = inst->getIntrinsicID();
+ assert(intrinId != llvm::Intrinsic::not_intrinsic);
+
+ // First lookup the intrinsic across different dialects for known
+ // supported conversions, examples include arm-neon, nvm-sve, etc.
+ Dialect *dialect = nullptr;
+
+ if (!moduleImport.useUnregisteredIntrinsicsOnly())
+ dialect = intrinsicToDialect.lookup(intrinId);
+
+ // No specialized (supported) intrinsics, attempt to generate a generic
+ // version via llvm.call_intrinsic (if available).
+ if (!dialect)
+ return convertUnregisteredIntrinsic(builder, inst, moduleImport);
+
+ // Dispatch the conversion to the dialect interface.
+ const LLVMImportDialectInterface *iface = getInterfaceFor(dialect);
+ assert(iface && "expected to find a dialect interface");
+ return iface->convertIntrinsic(builder, inst, moduleImport);
+}
diff --git a/mlir/lib/Target/LLVMIR/ModuleImport.cpp b/mlir/lib/Target/LLVMIR/ModuleImport.cpp
index ab187cd05de75..f5dc55277cc12 100644
--- a/mlir/lib/Target/LLVMIR/ModuleImport.cpp
+++ b/mlir/lib/Target/LLVMIR/ModuleImport.cpp
@@ -162,7 +162,8 @@ getTopologicallySortedBlocks(ArrayRef<llvm::BasicBlock *> basicBlocks) {
ModuleImport::ModuleImport(ModuleOp mlirModule,
std::unique_ptr<llvm::Module> llvmModule,
bool emitExpensiveWarnings,
- bool importEmptyDICompositeTypes)
+ bool importEmptyDICompositeTypes,
+ bool preferUnregisteredIntrinsics)
: builder(mlirModule->getContext()), context(mlirModule->getContext()),
mlirModule(mlirModule), llvmModule(std::move(llvmModule)),
iface(mlirModule->getContext()),
@@ -171,7 +172,8 @@ ModuleImport::ModuleImport(ModuleOp mlirModule,
mlirModule, importEmptyDICompositeTypes)),
loopAnnotationImporter(
std::make_unique<LoopAnnotationImporter>(*this, builder)),
- emitExpensiveWarnings(emitExpensiveWarnings) {
+ emitExpensiveWarnings(emitExpensiveWarnings),
+ preferUnregisteredIntrinsics(preferUnregisteredIntrinsics) {
builder.setInsertionPointToStart(mlirModule.getBody());
}
@@ -2552,11 +2554,10 @@ ModuleImport::translateDereferenceableAttr(const llvm::MDNode *node,
return derefAttr;
}
-OwningOpRef<ModuleOp>
-mlir::translateLLVMIRToModule(std::unique_ptr<llvm::Module> llvmModule,
- MLIRContext *context, bool emitExpensiveWarnings,
- bool dropDICompositeTypeElements,
- bool loadAllDialects) {
+OwningOpRef<ModuleOp> mlir::translateLLVMIRToModule(
+ std::unique_ptr<llvm::Module> llvmModule, MLIRContext *context,
+ bool emitExpensiveWarnings, bool dropDICompositeTypeElements,
+ bool loadAllDialects, bool preferUnregisteredIntrinsics) {
// 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
@@ -2573,7 +2574,8 @@ mlir::translateLLVMIRToModule(std::unique_ptr<llvm::Module> llvmModule,
/*column=*/0)));
ModuleImport moduleImport(module.get(), std::move(llvmModule),
- emitExpensiveWarnings, dropDICompositeTypeElements);
+ emitExpensiveWarnings, dropDICompositeTypeElements,
+ preferUnregisteredIntrinsics);
if (failed(moduleImport.initializeImportInterface()))
return {};
if (failed(moduleImport.convertDataLayout()))
diff --git a/mlir/test/Target/LLVMIR/Import/intrinsic-prefer-unregistered.ll b/mlir/test/Target/LLVMIR/Import/intrinsic-prefer-unregistered.ll
new file mode 100644
index 0000000000000..778289469c4a5
--- /dev/null
+++ b/mlir/test/Target/LLVMIR/Import/intrinsic-prefer-unregistered.ll
@@ -0,0 +1,10 @@
+; RUN: mlir-translate -import-llvm -prefer-unregistered-intrinsics %s | FileCheck %s
+
+; CHECK-LABEL: llvm.func @lifetime
+define void @lifetime(ptr %0) {
+ ; CHECK: llvm.call_intrinsic "llvm.lifetime.start.p0"({{.*}}, %arg0) : (i64, !llvm.ptr {llvm.nonnull}) -> !llvm.void
+ call void @llvm.lifetime.start.p0(i64 16, ptr nonnull %0)
+ ; CHECK: llvm.call_intrinsic "llvm.lifetime.end.p0"({{.*}}, %arg0) : (i64, !llvm.ptr {llvm.nonnull}) -> !llvm.void
+ call void @llvm.lifetime.end.p0(i64 32, ptr nonnull %0)
+ ret void
+}
>From 1e7625054d92d3333abc587ef9533cd1a070be15 Mon Sep 17 00:00:00 2001
From: Bruno Cardoso Lopes <bruno.cardoso at gmail.com>
Date: Thu, 13 Mar 2025 18:28:09 -0700
Subject: [PATCH 2/3] Add warning to comment
---
mlir/include/mlir/Target/LLVMIR/Import.h | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)
diff --git a/mlir/include/mlir/Target/LLVMIR/Import.h b/mlir/include/mlir/Target/LLVMIR/Import.h
index 2fef44947b6c2..c6181243a06b0 100644
--- a/mlir/include/mlir/Target/LLVMIR/Import.h
+++ b/mlir/include/mlir/Target/LLVMIR/Import.h
@@ -42,8 +42,10 @@ class ModuleOp;
/// The `loadAllDialects` flag (default on) will load all dialects in the
/// context.
/// The `preferUnregisteredIntrinsics` flag (default off) controls whether to
-/// prefer generic version of imported intrinsics with `llvm.intrinsic_call`
-/// than using versions supported by a dialects.
+/// import all intrinsics using `llvm.intrinsic_call` even if a dialect
+/// registered an explicit intrinsic operation. Warning: passes that rely on
+/// matching explicit intrinsic operations may not work properly if this flag is
+/// enabled.
OwningOpRef<ModuleOp> translateLLVMIRToModule(
std::unique_ptr<llvm::Module> llvmModule, MLIRContext *context,
bool emitExpensiveWarnings = true, bool dropDICompositeTypeElements = false,
>From 201ff571e4bc3a432c0b4fd8f524497f56a02d2a Mon Sep 17 00:00:00 2001
From: Bruno Cardoso Lopes <bruno.cardoso at gmail.com>
Date: Fri, 14 Mar 2025 11:31:43 -0700
Subject: [PATCH 3/3] Address review
---
mlir/include/mlir/Target/LLVMIR/ModuleImport.h | 4 ++--
mlir/lib/Target/LLVMIR/ConvertFromLLVMIR.cpp | 2 +-
2 files changed, 3 insertions(+), 3 deletions(-)
diff --git a/mlir/include/mlir/Target/LLVMIR/ModuleImport.h b/mlir/include/mlir/Target/LLVMIR/ModuleImport.h
index a69b8e75e6ef9..6763a7831f25f 100644
--- a/mlir/include/mlir/Target/LLVMIR/ModuleImport.h
+++ b/mlir/include/mlir/Target/LLVMIR/ModuleImport.h
@@ -489,8 +489,8 @@ class ModuleImport {
/// metadata that otherwise dominate the translation time for large inputs.
bool emitExpensiveWarnings;
- /// An option to control whether to disable supported intrinsic support in
- /// favor a more generic version via `llvm.intrinsic_call`.
+ /// An option to control whether the importer should try to convert all
+ /// intrinsics to llvm.call_intrinsic instead of dialect supported operations.
bool preferUnregisteredIntrinsics;
};
diff --git a/mlir/lib/Target/LLVMIR/ConvertFromLLVMIR.cpp b/mlir/lib/Target/LLVMIR/ConvertFromLLVMIR.cpp
index b10fdd6f37f79..b21db4aa18284 100644
--- a/mlir/lib/Target/LLVMIR/ConvertFromLLVMIR.cpp
+++ b/mlir/lib/Target/LLVMIR/ConvertFromLLVMIR.cpp
@@ -40,7 +40,7 @@ void registerFromLLVMIRTranslation() {
static llvm::cl::opt<bool> preferUnregisteredIntrinsics(
"prefer-unregistered-intrinsics",
llvm::cl::desc(
- "Prefer translation all intrinsics into llvm.call_intrinsic instead "
+ "Prefer translating all intrinsics into llvm.call_intrinsic instead "
"of using dialect supported intrinsics"),
llvm::cl::init(false));
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