[Mlir-commits] [mlir] [MLIR][LLVM] Share LLVM metadata attribute translation (PR #203016)
Akimasa Watanuki
llvmlistbot at llvm.org
Wed Jun 10 08:30:17 PDT 2026
https://github.com/Men-cotton created https://github.com/llvm/llvm-project/pull/203016
Share LLVM dialect metadata materialization through ModuleTranslation so named metadata and metadata-as-value lowering use one conversion path. Resolve metadata symbol references to functions, globals, aliases, and ifuncs, and diagnose malformed required metadata before lowering.
>From caae8f80cbffae7206e38d20500cc2299feb8e4f Mon Sep 17 00:00:00 2001
From: mencotton <mencotton0410 at gmail.com>
Date: Mon, 8 Jun 2026 20:51:28 +0900
Subject: [PATCH] [MLIR][LLVM] Share LLVM metadata attribute translation
Share LLVM dialect metadata materialization through ModuleTranslation so named
metadata and metadata-as-value lowering use one conversion path. Resolve metadata
symbol references to functions, globals, aliases, and ifuncs, and diagnose
malformed required metadata before lowering.
---
.../mlir/Dialect/LLVMIR/LLVMAttrDefs.td | 4 ++
mlir/include/mlir/Dialect/LLVMIR/LLVMOps.td | 21 ++++---
.../mlir/Target/LLVMIR/ModuleTranslation.h | 9 +++
.../LLVMIR/LLVMToLLVMIRTranslation.cpp | 61 ++++++-------------
mlir/lib/Target/LLVMIR/ModuleTranslation.cpp | 50 +++++++++++++++
mlir/test/Dialect/LLVMIR/call-intrin.mlir | 13 ++++
mlir/test/Dialect/LLVMIR/invalid.mlir | 5 ++
mlir/test/Target/LLVMIR/llvmir-invalid.mlir | 17 ++++++
.../Target/LLVMIR/llvmir-named-metadata.mlir | 31 ++++++++++
9 files changed, 159 insertions(+), 52 deletions(-)
diff --git a/mlir/include/mlir/Dialect/LLVMIR/LLVMAttrDefs.td b/mlir/include/mlir/Dialect/LLVMIR/LLVMAttrDefs.td
index 56f3afba6a030e..4cf47716642905 100644
--- a/mlir/include/mlir/Dialect/LLVMIR/LLVMAttrDefs.td
+++ b/mlir/include/mlir/Dialect/LLVMIR/LLVMAttrDefs.td
@@ -1784,6 +1784,10 @@ def LLVM_MDNodeAttr : LLVM_Attr<"MDNode", "md_node"> {
let assemblyFormat = "`<` (`>`) : ($operands^ `>`)?";
}
+def LLVM_MDNodeArrayAttr
+ : TypedArrayAttrBase<LLVM_MDNodeAttr,
+ "array of #llvm.md_node attributes">;
+
def LLVM_AnyMDAttr : AnyAttrOf<[
LLVM_MDStringAttr, LLVM_MDConstantAttr, LLVM_MDFuncAttr, LLVM_MDNodeAttr],
"LLVM metadata attribute (md_string, md_const, md_func, or md_node)">;
diff --git a/mlir/include/mlir/Dialect/LLVMIR/LLVMOps.td b/mlir/include/mlir/Dialect/LLVMIR/LLVMOps.td
index 85b768f2f6755d..c813d71fdc7735 100644
--- a/mlir/include/mlir/Dialect/LLVMIR/LLVMOps.td
+++ b/mlir/include/mlir/Dialect/LLVMIR/LLVMOps.td
@@ -2521,7 +2521,8 @@ def LLVM_MetadataAsValueOp
* `#llvm.md_string<"...">` -> `llvm::MDString`.
* `#llvm.md_const<...>` -> `llvm::ConstantAsMetadata`.
- * `#llvm.md_func<@symbol>` -> `llvm::ValueAsMetadata` of a function.
+ * `#llvm.md_func<@symbol>` -> `llvm::ValueAsMetadata` of a function or
+ global value.
* `#llvm.md_node<...>` -> `llvm::MDNode` over any of the above.
These can be nested arbitrarily to form metadata trees. Lowering to LLVM
@@ -2555,12 +2556,14 @@ def LLVM_MetadataAsValueOp
];
let llvmBuilder = [{
- ::llvm::Metadata *md = convertMetadataAttr(
- op.getMetadataAttr(), builder, moduleTranslation);
- if (!md)
- return ::mlir::emitError(op.getLoc(),
- "llvm.mlir.metadata_as_value: cannot lower metadata attribute");
- $res = ::llvm::MetadataAsValue::get(builder.getContext(), md);
+ ::mlir::FailureOr<::llvm::Metadata *> md =
+ moduleTranslation.convertMetadataAttr(op.getMetadataAttr(), [&]() {
+ return ::mlir::emitError(op.getLoc(),
+ "llvm.mlir.metadata_as_value: cannot lower metadata attribute: ");
+ });
+ if (::mlir::failed(md))
+ return ::mlir::failure();
+ $res = ::llvm::MetadataAsValue::get(builder.getContext(), *md);
}];
let hasFolder = 1;
@@ -2705,13 +2708,13 @@ def LLVM_NamedMetadataOp
]
```
}];
- let arguments = (ins StrAttr:$metadata_name, ArrayAttr:$nodes);
+ let arguments = (ins StrAttr:$metadata_name, LLVM_MDNodeArrayAttr:$nodes);
let assemblyFormat = [{
$metadata_name $nodes attr-dict
}];
let llvmBuilder = [{
- convertNamedMetadataOp($metadata_name, $nodes, builder, moduleTranslation);
+ return convertNamedMetadataOp(op, moduleTranslation);
}];
}
diff --git a/mlir/include/mlir/Target/LLVMIR/ModuleTranslation.h b/mlir/include/mlir/Target/LLVMIR/ModuleTranslation.h
index c5c4b105ee1521..b23f78ff0f98a8 100644
--- a/mlir/include/mlir/Target/LLVMIR/ModuleTranslation.h
+++ b/mlir/include/mlir/Target/LLVMIR/ModuleTranslation.h
@@ -19,6 +19,7 @@
#include "mlir/IR/Operation.h"
#include "mlir/IR/SymbolTable.h"
#include "mlir/IR/Value.h"
+#include "mlir/Support/LLVM.h"
#include "mlir/Support/StateStack.h"
#include "mlir/Target/LLVMIR/Export.h"
#include "mlir/Target/LLVMIR/LLVMTranslationInterface.h"
@@ -34,6 +35,7 @@ class CallBase;
class CanonicalLoopInfo;
class Function;
class IRBuilderBase;
+class Metadata;
class OpenMPIRBuilder;
class Value;
namespace vfs {
@@ -345,6 +347,13 @@ class ModuleTranslation {
/// it if it does not exist.
llvm::NamedMDNode *getOrInsertNamedModuleMetadata(StringRef name);
+ /// Converts an LLVM dialect metadata attribute to LLVM IR metadata.
+ /// Returns failure and emits a diagnostic using `emitError` if the attribute
+ /// cannot be converted.
+ FailureOr<llvm::Metadata *>
+ convertMetadataAttr(Attribute attr,
+ function_ref<InFlightDiagnostic()> emitError);
+
/// Creates a stack frame of type `T` on ModuleTranslation stack. `T` must
/// be derived from `StackFrameBase<T>` and constructible from the provided
/// arguments. Doing this before entering the region of the op being
diff --git a/mlir/lib/Target/LLVMIR/Dialect/LLVMIR/LLVMToLLVMIRTranslation.cpp b/mlir/lib/Target/LLVMIR/Dialect/LLVMIR/LLVMToLLVMIRTranslation.cpp
index 5474689c9b0b5c..1e7a6072eadd57 100644
--- a/mlir/lib/Target/LLVMIR/Dialect/LLVMIR/LLVMToLLVMIRTranslation.cpp
+++ b/mlir/lib/Target/LLVMIR/Dialect/LLVMIR/LLVMToLLVMIRTranslation.cpp
@@ -210,52 +210,27 @@ convertCallLLVMIntrinsicOp(CallIntrinsicOp op, llvm::IRBuilderBase &builder,
return success();
}
-/// Recursively converts an MLIR metadata attribute to an LLVM metadata node.
-static llvm::Metadata *
-convertMetadataAttr(Attribute attr, llvm::IRBuilderBase &builder,
- LLVM::ModuleTranslation &moduleTranslation) {
- return llvm::TypeSwitch<Attribute, llvm::Metadata *>(attr)
- .Case<LLVM::MDStringAttr>([&](auto a) -> llvm::Metadata * {
- return llvm::MDString::get(builder.getContext(),
- a.getValue().getValue());
- })
- .Case<LLVM::MDConstantAttr>([&](auto a) -> llvm::Metadata * {
- IntegerAttr intAttr = llvm::dyn_cast<IntegerAttr>(a.getValue());
- if (!intAttr)
- return nullptr;
- return llvm::ConstantAsMetadata::get(llvm::ConstantInt::get(
- llvm::Type::getIntNTy(builder.getContext(),
- intAttr.getType().getIntOrFloatBitWidth()),
- intAttr.getValue()));
- })
- .Case<LLVM::MDFuncAttr>([&](auto a) -> llvm::Metadata * {
- if (llvm::Function *fn =
- moduleTranslation.lookupFunction(a.getName().getValue()))
- return llvm::ValueAsMetadata::get(fn);
- return nullptr;
- })
- .Case<LLVM::MDNodeAttr>([&](auto a) -> llvm::Metadata * {
- SmallVector<llvm::Metadata *> operands;
- for (Attribute op : a.getOperands())
- operands.push_back(
- convertMetadataAttr(op, builder, moduleTranslation));
- return llvm::MDNode::get(builder.getContext(), operands);
- })
- .Default([](auto) -> llvm::Metadata * { return nullptr; });
-}
-
-static void convertNamedMetadataOp(StringRef metadataName, ArrayAttr nodes,
- llvm::IRBuilderBase &builder,
- LLVM::ModuleTranslation &moduleTranslation) {
+static LogicalResult
+convertNamedMetadataOp(NamedMetadataOp op,
+ LLVM::ModuleTranslation &moduleTranslation) {
llvm::Module *llvmModule = moduleTranslation.getLLVMModule();
llvm::NamedMDNode *namedMD =
- llvmModule->getOrInsertNamedMetadata(metadataName);
- for (Attribute nodeAttr : nodes) {
- llvm::Metadata *md =
- convertMetadataAttr(nodeAttr, builder, moduleTranslation);
- if (auto *mdNode = llvm::dyn_cast_or_null<llvm::MDNode>(md))
- namedMD->addOperand(mdNode);
+ llvmModule->getOrInsertNamedMetadata(op.getMetadataName());
+ for (Attribute nodeAttr : op.getNodes()) {
+ FailureOr<llvm::Metadata *> md =
+ moduleTranslation.convertMetadataAttr(nodeAttr, [&]() {
+ return op.emitError() << "failed to convert named metadata '"
+ << op.getMetadataName() << "': ";
+ });
+ if (failed(md))
+ return failure();
+ auto *mdNode = llvm::dyn_cast_if_present<llvm::MDNode>(*md);
+ if (!mdNode)
+ return op.emitError() << "failed to convert named metadata '"
+ << op.getMetadataName() << "'";
+ namedMD->addOperand(mdNode);
}
+ return success();
}
static void convertLinkerOptionsOp(ArrayAttr options,
diff --git a/mlir/lib/Target/LLVMIR/ModuleTranslation.cpp b/mlir/lib/Target/LLVMIR/ModuleTranslation.cpp
index 01d3e9c4a62ce6..7d3a4c6346b0ab 100644
--- a/mlir/lib/Target/LLVMIR/ModuleTranslation.cpp
+++ b/mlir/lib/Target/LLVMIR/ModuleTranslation.cpp
@@ -1567,6 +1567,56 @@ static llvm::MDNode *convertIntegerArrayToMDNode(llvm::LLVMContext &context,
return llvm::MDNode::get(context, mdValues);
}
+FailureOr<llvm::Metadata *> ModuleTranslation::convertMetadataAttr(
+ Attribute attr, function_ref<InFlightDiagnostic()> emitError) {
+ llvm::LLVMContext &llvmContext = getLLVMContext();
+
+ return llvm::TypeSwitch<Attribute, FailureOr<llvm::Metadata *>>(attr)
+ .Case<MDStringAttr>([&](auto a) -> FailureOr<llvm::Metadata *> {
+ return llvm::MDString::get(llvmContext, a.getValue().getValue());
+ })
+ .Case<MDConstantAttr>([&](auto a) -> FailureOr<llvm::Metadata *> {
+ IntegerAttr intAttr = llvm::dyn_cast<IntegerAttr>(a.getValue());
+ if (!intAttr)
+ return emitError()
+ << "expected integer attribute in metadata constant";
+ return llvm::ConstantAsMetadata::get(llvm::ConstantInt::get(
+ llvm::Type::getIntNTy(llvmContext,
+ intAttr.getType().getIntOrFloatBitWidth()),
+ intAttr.getValue()));
+ })
+ .Case<MDFuncAttr>([&](auto a) -> FailureOr<llvm::Metadata *> {
+ if (llvm::Function *fn = lookupFunction(a.getName().getValue()))
+ return llvm::ValueAsMetadata::get(fn);
+ if (llvm::GlobalValue *global = lookupGlobal(a.getName().getValue()))
+ return llvm::ValueAsMetadata::get(global);
+ Operation *symbol =
+ symbolTable().lookupSymbolIn(mlirModule, a.getName());
+ if (auto alias = dyn_cast_if_present<LLVM::AliasOp>(symbol))
+ if (llvm::GlobalValue *global = lookupAlias(alias))
+ return llvm::ValueAsMetadata::get(global);
+ if (auto ifunc = dyn_cast_if_present<LLVM::IFuncOp>(symbol))
+ if (llvm::GlobalValue *global = lookupIFunc(ifunc))
+ return llvm::ValueAsMetadata::get(global);
+ return emitError() << "could not resolve metadata reference '"
+ << a.getName() << "'";
+ })
+ .Case<MDNodeAttr>([&](auto a) -> FailureOr<llvm::Metadata *> {
+ SmallVector<llvm::Metadata *> operands;
+ for (Attribute operand : a.getOperands()) {
+ FailureOr<llvm::Metadata *> md =
+ convertMetadataAttr(operand, emitError);
+ if (failed(md))
+ return failure();
+ operands.push_back(*md);
+ }
+ return llvm::MDNode::get(llvmContext, operands);
+ })
+ .Default([&](Attribute attr) -> FailureOr<llvm::Metadata *> {
+ return emitError() << "unsupported LLVM metadata attribute " << attr;
+ });
+}
+
LogicalResult ModuleTranslation::convertOneFunction(LLVMFuncOp func) {
// Clear the block, branch value mappings, they are only relevant within one
// function.
diff --git a/mlir/test/Dialect/LLVMIR/call-intrin.mlir b/mlir/test/Dialect/LLVMIR/call-intrin.mlir
index 7a12e09eb6480f..e0e1127e24acae 100644
--- a/mlir/test/Dialect/LLVMIR/call-intrin.mlir
+++ b/mlir/test/Dialect/LLVMIR/call-intrin.mlir
@@ -146,3 +146,16 @@ llvm.func @read_named_register() -> i32 {
: (!llvm.metadata) -> i32
llvm.return %r : i32
}
+
+// -----
+
+llvm.mlir.global internal @metadata_global(0 : i32) : i32
+
+// CHECK-LABEL: define i32 @read_global_ref_metadata()
+// CHECK: call i32 @llvm.read_register.i32(metadata ptr @metadata_global)
+llvm.func @read_global_ref_metadata() -> i32 {
+ %md = llvm.mlir.metadata_as_value #llvm.md_node<#llvm.md_func<@metadata_global>>
+ %r = llvm.call_intrinsic "llvm.read_register.i32"(%md)
+ : (!llvm.metadata) -> i32
+ llvm.return %r : i32
+}
diff --git a/mlir/test/Dialect/LLVMIR/invalid.mlir b/mlir/test/Dialect/LLVMIR/invalid.mlir
index e80094df1eed27..98180849223a3b 100644
--- a/mlir/test/Dialect/LLVMIR/invalid.mlir
+++ b/mlir/test/Dialect/LLVMIR/invalid.mlir
@@ -1847,6 +1847,11 @@ llvm.mlir.alias external @y5 : i32 {
// -----
+// expected-error at +1{{attribute 'nodes' failed to satisfy constraint: array of #llvm.md_node attributes}}
+llvm.named_metadata "not_node" [#llvm.md_string<"int">]
+
+// -----
+
module {
llvm.func @foo()
diff --git a/mlir/test/Target/LLVMIR/llvmir-invalid.mlir b/mlir/test/Target/LLVMIR/llvmir-invalid.mlir
index c263afe5537503..ef6681ca3821f6 100644
--- a/mlir/test/Target/LLVMIR/llvmir-invalid.mlir
+++ b/mlir/test/Target/LLVMIR/llvmir-invalid.mlir
@@ -305,6 +305,23 @@ module attributes {} {
// -----
+// expected-error @below{{failed to convert named metadata 'bad': expected integer attribute in metadata constant}}
+// expected-error @below{{LLVM Translation failed for operation: llvm.named_metadata}}
+llvm.named_metadata "bad" [
+ #llvm.md_node<#llvm.md_const<"not an integer">>
+]
+
+// -----
+
+llvm.func @bad_metadata_as_value() {
+ // expected-error @below{{llvm.mlir.metadata_as_value: cannot lower metadata attribute: expected integer attribute in metadata constant}}
+ // expected-error @below{{LLVM Translation failed for operation: llvm.mlir.metadata_as_value}}
+ %0 = llvm.mlir.metadata_as_value #llvm.md_node<#llvm.md_const<"not an integer">>
+ llvm.return
+}
+
+// -----
+
module @does_not_exist {
// expected-error @below{{resource does not exist}}
llvm.mlir.global internal constant @constant(dense_resource<test0> : tensor<4xf32>) : !llvm.array<4 x f32>
diff --git a/mlir/test/Target/LLVMIR/llvmir-named-metadata.mlir b/mlir/test/Target/LLVMIR/llvmir-named-metadata.mlir
index 493616430c8227..9f09062c2a44b3 100644
--- a/mlir/test/Target/LLVMIR/llvmir-named-metadata.mlir
+++ b/mlir/test/Target/LLVMIR/llvmir-named-metadata.mlir
@@ -5,11 +5,34 @@
// CHECK: !foo.version = !{![[VERSION:[0-9]+]]}
// CHECK: !foo.language_version = !{![[LANG:[0-9]+]]}
// CHECK: !foo.kernel = !{![[KERNEL:[0-9]+]]}
+// CHECK: !foo.global_refs = !{![[GLOBAL_REFS:[0-9]+]]}
llvm.func @my_kernel() {
llvm.return
}
+llvm.mlir.global internal @metadata_global(0 : i32) : i32
+
+llvm.func @metadata_alias_target() {
+ llvm.return
+}
+
+llvm.mlir.alias external @metadata_alias : !llvm.func<void ()> {
+ %0 = llvm.mlir.addressof @metadata_alias_target : !llvm.ptr
+ llvm.return %0 : !llvm.ptr
+}
+
+llvm.mlir.ifunc external @metadata_ifunc : !llvm.func<void ()>, !llvm.ptr @metadata_ifunc_resolver
+
+llvm.func @metadata_ifunc_resolver() -> !llvm.ptr {
+ %0 = llvm.mlir.addressof @metadata_ifunc_target : !llvm.ptr
+ llvm.return %0 : !llvm.ptr
+}
+
+llvm.func @metadata_ifunc_target() {
+ llvm.return
+}
+
llvm.named_metadata "foo.version" [
#llvm.md_node<#llvm.md_const<1 : i32>,
#llvm.md_const<0 : i32>,
@@ -43,3 +66,11 @@ llvm.named_metadata "foo.kernel" [
// CHECK-DAG: ![[KERNEL]] = !{ptr @my_kernel, ![[EMPTY:[0-9]+]], ![[ARGS:[0-9]+]]}
// CHECK-DAG: ![[EMPTY]] = !{}
// CHECK-DAG: ![[ARGS]] = !{![[A0]]}
+
+llvm.named_metadata "foo.global_refs" [
+ #llvm.md_node<
+ #llvm.md_func<@metadata_global>,
+ #llvm.md_func<@metadata_alias>,
+ #llvm.md_func<@metadata_ifunc>>
+]
+// CHECK-DAG: ![[GLOBAL_REFS]] = !{ptr @metadata_global, ptr @metadata_alias, ptr @metadata_ifunc}
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