[Mlir-commits] [mlir] 4469ec1 - [mlir][llvm] Import alias scope metadata from LLVM IR.

Tobias Gysi llvmlistbot at llvm.org
Thu Feb 16 00:54:21 PST 2023


Author: Tobias Gysi
Date: 2023-02-16T09:52:59+01:00
New Revision: 4469ec1d196ff737e9e18320a124023bb420dfed

URL: https://github.com/llvm/llvm-project/commit/4469ec1d196ff737e9e18320a124023bb420dfed
DIFF: https://github.com/llvm/llvm-project/commit/4469ec1d196ff737e9e18320a124023bb420dfed.diff

LOG: [mlir][llvm] Import alias scope metadata from LLVM IR.

The revision adds support for importing alias.scope and noalias metadata
from LLVM IR into LLVM dialect. It also adds a verifier to the
AliasScopeMetadataOp to check that the associated domain exists
and is of type AliasScopeDomainMetadataOp.

Reviewed By: Dinistro

Differential Revision: https://reviews.llvm.org/D143923

Added: 
    mlir/test/Target/LLVMIR/Import/metadata-alias-scopes.ll

Modified: 
    mlir/include/mlir/Dialect/LLVMIR/LLVMOps.td
    mlir/include/mlir/Target/LLVMIR/ModuleImport.h
    mlir/lib/Dialect/LLVMIR/IR/LLVMDialect.cpp
    mlir/lib/Target/LLVMIR/Dialect/LLVMIR/LLVMIRToLLVMTranslation.cpp
    mlir/lib/Target/LLVMIR/ModuleImport.cpp
    mlir/test/Dialect/LLVMIR/invalid.mlir
    mlir/test/Target/LLVMIR/Import/import-failure.ll

Removed: 
    


################################################################################
diff  --git a/mlir/include/mlir/Dialect/LLVMIR/LLVMOps.td b/mlir/include/mlir/Dialect/LLVMIR/LLVMOps.td
index 001f5ac22a6df..be995c8e722c5 100644
--- a/mlir/include/mlir/Dialect/LLVMIR/LLVMOps.td
+++ b/mlir/include/mlir/Dialect/LLVMIR/LLVMOps.td
@@ -1095,6 +1095,7 @@ def LLVM_AliasScopeMetadataOp : LLVM_Op<"alias_scope", [
     https://llvm.org/docs/LangRef.html#noalias-and-alias-scope-metadata
   }];
   let assemblyFormat = "$sym_name attr-dict";
+  let hasVerifier = 1;
 }
 
 def LLVM_AccessGroupMetadataOp : LLVM_Op<"access_group", [

diff  --git a/mlir/include/mlir/Target/LLVMIR/ModuleImport.h b/mlir/include/mlir/Target/LLVMIR/ModuleImport.h
index 3265c32372410..aaf9b2cf55efe 100644
--- a/mlir/include/mlir/Target/LLVMIR/ModuleImport.h
+++ b/mlir/include/mlir/Target/LLVMIR/ModuleImport.h
@@ -176,6 +176,12 @@ class ModuleImport {
   LoopAnnotationAttr translateLoopAnnotationAttr(const llvm::MDNode *node,
                                                  Location loc) const;
 
+  /// Returns the symbol references pointing to the alias scope operations that
+  /// map to the alias scope nodes starting from the metadata `node`. Returns
+  /// failure, if any of the symbol references cannot be found.
+  FailureOr<SmallVector<SymbolRefAttr>>
+  lookupAliasScopeAttrs(const llvm::MDNode *node) const;
+
 private:
   /// Clears the block and value mapping before processing a new region.
   void clearBlockAndValueMapping() {
@@ -268,6 +274,12 @@ class ModuleImport {
   /// symbol pointing to the translated operation. Returns success if all
   /// conversions succeed and failure otherwise.
   LogicalResult processAccessGroupMetadata(const llvm::MDNode *node);
+  /// Converts all LLVM alias scopes and domains starting from `node` to MLIR
+  /// alias scope and domain operations and stores a mapping from every nested
+  /// alias scope or alias domain node to the symbol pointing to the translated
+  /// operation. Returns success if all conversions succeed and failure
+  /// otherwise.
+  LogicalResult processAliasScopeMetadata(const llvm::MDNode *node);
 
   /// Builder pointing at where the next instruction should be generated.
   OpBuilder builder;
@@ -298,9 +310,11 @@ class ModuleImport {
   /// operations for all operations that return no result. All operations that
   /// return a result have a valueMapping entry instead.
   DenseMap<llvm::Instruction *, Operation *> noResultOpMapping;
-  /// Mapping between LLVM TBAA metadata nodes and symbol references
-  /// to the LLVMIR dialect TBAA operations corresponding to these
-  /// nodes.
+  /// Mapping between LLVM alias scope and domain metadata nodes and symbol
+  /// references to the LLVM dialect operations corresponding to these nodes.
+  DenseMap<const llvm::MDNode *, SymbolRefAttr> aliasScopeMapping;
+  /// Mapping between LLVM TBAA metadata nodes and symbol references to the LLVM
+  /// dialect TBAA operations corresponding to these nodes.
   DenseMap<const llvm::MDNode *, SymbolRefAttr> tbaaMapping;
   /// The stateful type translator (contains named structs).
   LLVM::TypeFromLLVMIRTranslator typeTranslator;

diff  --git a/mlir/lib/Dialect/LLVMIR/IR/LLVMDialect.cpp b/mlir/lib/Dialect/LLVMIR/IR/LLVMDialect.cpp
index d5069214c8f0f..ee152f75432fa 100644
--- a/mlir/lib/Dialect/LLVMIR/IR/LLVMDialect.cpp
+++ b/mlir/lib/Dialect/LLVMIR/IR/LLVMDialect.cpp
@@ -2734,6 +2734,21 @@ LogicalResult TBAATypeDescriptorOp::verify() {
   return success();
 }
 
+//===----------------------------------------------------------------------===//
+// AliasScopeMetadataOp
+//===----------------------------------------------------------------------===//
+
+LogicalResult AliasScopeMetadataOp::verify() {
+  Operation *domainOp = SymbolTable::lookupNearestSymbolFrom(
+      this->getOperation(), getDomainAttr());
+  if (!isa_and_nonnull<AliasScopeDomainMetadataOp>(domainOp)) {
+    return this->emitOpError()
+           << "expected '" << getDomain()
+           << "' to reference a domain operation in the same region";
+  }
+  return success();
+}
+
 //===----------------------------------------------------------------------===//
 // OpAsmDialectInterface
 //===----------------------------------------------------------------------===//

diff  --git a/mlir/lib/Target/LLVMIR/Dialect/LLVMIR/LLVMIRToLLVMTranslation.cpp b/mlir/lib/Target/LLVMIR/Dialect/LLVMIR/LLVMIRToLLVMTranslation.cpp
index e58d267e31714..88f0688180a33 100644
--- a/mlir/lib/Target/LLVMIR/Dialect/LLVMIR/LLVMIRToLLVMTranslation.cpp
+++ b/mlir/lib/Target/LLVMIR/Dialect/LLVMIR/LLVMIRToLLVMTranslation.cpp
@@ -71,8 +71,9 @@ static LogicalResult convertIntrinsicImpl(OpBuilder &odsBuilder,
 /// dialect attributes.
 static ArrayRef<unsigned> getSupportedMetadataImpl() {
   static const SmallVector<unsigned> convertibleMetadata = {
-      llvm::LLVMContext::MD_prof, llvm::LLVMContext::MD_tbaa,
-      llvm::LLVMContext::MD_access_group, llvm::LLVMContext::MD_loop};
+      llvm::LLVMContext::MD_prof,         llvm::LLVMContext::MD_tbaa,
+      llvm::LLVMContext::MD_access_group, llvm::LLVMContext::MD_loop,
+      llvm::LLVMContext::MD_noalias,      llvm::LLVMContext::MD_alias_scope};
   return convertibleMetadata;
 }
 
@@ -178,8 +179,9 @@ static LogicalResult setTBAAAttr(const llvm::MDNode *node, Operation *op,
 /// that map to the access group nodes starting from the access group metadata
 /// `node`, and attaches all of them to the imported operation if the lookups
 /// succeed. Returns failure otherwise.
-static LogicalResult setAccessGroupAttr(const llvm::MDNode *node, Operation *op,
-                                        LLVM::ModuleImport &moduleImport) {
+static LogicalResult setAccessGroupsAttr(const llvm::MDNode *node,
+                                         Operation *op,
+                                         LLVM::ModuleImport &moduleImport) {
   FailureOr<SmallVector<SymbolRefAttr>> accessGroups =
       moduleImport.lookupAccessGroupAttrs(node);
   if (failed(accessGroups))
@@ -211,6 +213,45 @@ static LogicalResult setLoopAttr(const llvm::MDNode *node, Operation *op,
       .Default([](auto) { return failure(); });
 }
 
+/// Looks up all the symbol references pointing to the alias scope operations
+/// that map to the alias scope nodes starting from the alias scope metadata
+/// `node`, and attaches all of them to the imported operation if the lookups
+/// succeed. Returns failure otherwise.
+static LogicalResult setAliasScopesAttr(const llvm::MDNode *node, Operation *op,
+                                        LLVM::ModuleImport &moduleImport) {
+  FailureOr<SmallVector<SymbolRefAttr>> aliasScopes =
+      moduleImport.lookupAliasScopeAttrs(node);
+  if (failed(aliasScopes))
+    return failure();
+
+  SmallVector<Attribute> aliasScopeAttrs(aliasScopes->begin(),
+                                         aliasScopes->end());
+  return AttributeSetter<LoadOp, StoreOp>(op).apply([&](auto memOp) {
+    memOp.setAliasScopesAttr(
+        ArrayAttr::get(memOp.getContext(), aliasScopeAttrs));
+  });
+}
+
+/// Looks up all the symbol references pointing to the alias scope operations
+/// that map to the alias scope nodes starting from the noalias metadata `node`,
+/// and attaches all of them to the imported operation if the lookups succeed.
+/// Returns failure otherwise.
+static LogicalResult setNoaliasScopesAttr(const llvm::MDNode *node,
+                                          Operation *op,
+                                          LLVM::ModuleImport &moduleImport) {
+  FailureOr<SmallVector<SymbolRefAttr>> noaliasScopes =
+      moduleImport.lookupAliasScopeAttrs(node);
+  if (failed(noaliasScopes))
+    return failure();
+
+  SmallVector<Attribute> noaliasScopeAttrs(noaliasScopes->begin(),
+                                           noaliasScopes->end());
+  return AttributeSetter<LoadOp, StoreOp>(op).apply([&](auto memOp) {
+    memOp.setNoaliasScopesAttr(
+        ArrayAttr::get(memOp.getContext(), noaliasScopeAttrs));
+  });
+}
+
 namespace {
 
 /// Implementation of the dialect interface that converts operations belonging
@@ -238,9 +279,13 @@ class LLVMDialectLLVMIRImportInterface : public LLVMImportDialectInterface {
     if (kind == llvm::LLVMContext::MD_tbaa)
       return setTBAAAttr(node, op, moduleImport);
     if (kind == llvm::LLVMContext::MD_access_group)
-      return setAccessGroupAttr(node, op, moduleImport);
+      return setAccessGroupsAttr(node, op, moduleImport);
     if (kind == llvm::LLVMContext::MD_loop)
       return setLoopAttr(node, op, moduleImport);
+    if (kind == llvm::LLVMContext::MD_alias_scope)
+      return setAliasScopesAttr(node, op, moduleImport);
+    if (kind == llvm::LLVMContext::MD_noalias)
+      return setNoaliasScopesAttr(node, op, moduleImport);
 
     // A handler for a supported metadata kind is missing.
     llvm_unreachable("unknown metadata type");

diff  --git a/mlir/lib/Target/LLVMIR/ModuleImport.cpp b/mlir/lib/Target/LLVMIR/ModuleImport.cpp
index 992345686e716..ed462d8a9333f 100644
--- a/mlir/lib/Target/LLVMIR/ModuleImport.cpp
+++ b/mlir/lib/Target/LLVMIR/ModuleImport.cpp
@@ -521,6 +521,99 @@ ModuleImport::processAccessGroupMetadata(const llvm::MDNode *node) {
   return success();
 }
 
+LogicalResult
+ModuleImport::processAliasScopeMetadata(const llvm::MDNode *node) {
+  Location loc = mlirModule.getLoc();
+  // Helper that verifies the node has a self reference operand.
+  auto verifySelfRef = [](const llvm::MDNode *node) {
+    return node->getNumOperands() != 0 &&
+           node == dyn_cast<llvm::MDNode>(node->getOperand(0));
+  };
+  // Helper that verifies the given operand is a string or does not exist.
+  auto verifyDescription = [](const llvm::MDNode *node, unsigned idx) {
+    return idx >= node->getNumOperands() ||
+           isa<llvm::MDString>(node->getOperand(idx));
+  };
+  // Helper that creates an alias scope domain operation.
+  auto createAliasScopeDomainOp = [&](const llvm::MDNode *aliasDomain) {
+    StringAttr description = nullptr;
+    if (aliasDomain->getNumOperands() >= 2)
+      if (auto *operand = dyn_cast<llvm::MDString>(aliasDomain->getOperand(1)))
+        description = builder.getStringAttr(operand->getString());
+    std::string name = llvm::formatv("domain_{0}", aliasScopeMapping.size());
+    return builder.create<AliasScopeDomainMetadataOp>(loc, name, description);
+  };
+
+  // Collect the alias scopes and domains to translate them.
+  for (const llvm::MDOperand &operand : node->operands()) {
+    if (const auto *scope = dyn_cast<llvm::MDNode>(operand)) {
+      llvm::AliasScopeNode aliasScope(scope);
+      const llvm::MDNode *domain = aliasScope.getDomain();
+
+      // Verify the scope node points to valid scope metadata which includes
+      // verifying its domain. Perform the verification before looking it up in
+      // the alias scope mapping since it could have been inserted as a domain
+      // node before.
+      if (!verifySelfRef(scope) || !domain || !verifyDescription(scope, 2))
+        return emitError(loc) << "unsupported alias scope node: "
+                              << diagMD(scope, llvmModule.get());
+      if (!verifySelfRef(domain) || !verifyDescription(domain, 1))
+        return emitError(loc) << "unsupported alias domain node: "
+                              << diagMD(domain, llvmModule.get());
+
+      if (aliasScopeMapping.count(scope))
+        continue;
+
+      // Set the insertion point to the end of the global metadata operation.
+      MetadataOp metadataOp = getGlobalMetadataOp();
+      StringAttr metadataOpName =
+          SymbolTable::getSymbolName(getGlobalMetadataOp());
+      OpBuilder::InsertionGuard guard(builder);
+      builder.setInsertionPointToEnd(&metadataOp.getBody().back());
+
+      // Convert the domain metadata node if it has not been translated before.
+      auto it = aliasScopeMapping.find(aliasScope.getDomain());
+      if (it == aliasScopeMapping.end()) {
+        auto aliasScopeDomainOp = createAliasScopeDomainOp(domain);
+        auto symbolRef = SymbolRefAttr::get(
+            builder.getContext(), metadataOpName,
+            FlatSymbolRefAttr::get(builder.getContext(),
+                                   aliasScopeDomainOp.getSymName()));
+        it = aliasScopeMapping.try_emplace(domain, symbolRef).first;
+      }
+
+      // Convert the scope metadata node if it has not been converted before.
+      StringAttr description = nullptr;
+      if (!aliasScope.getName().empty())
+        description = builder.getStringAttr(aliasScope.getName());
+      std::string name = llvm::formatv("scope_{0}", aliasScopeMapping.size());
+      auto aliasScopeOp = builder.create<AliasScopeMetadataOp>(
+          loc, name, it->getSecond().getLeafReference().getValue(),
+          description);
+      auto symbolRef =
+          SymbolRefAttr::get(builder.getContext(), metadataOpName,
+                             FlatSymbolRefAttr::get(builder.getContext(),
+                                                    aliasScopeOp.getSymName()));
+      aliasScopeMapping.try_emplace(aliasScope.getNode(), symbolRef);
+    }
+  }
+  return success();
+}
+
+FailureOr<SmallVector<SymbolRefAttr>>
+ModuleImport::lookupAliasScopeAttrs(const llvm::MDNode *node) const {
+  SmallVector<SymbolRefAttr> aliasScopes;
+  aliasScopes.reserve(node->getNumOperands());
+  for (const llvm::MDOperand &operand : node->operands()) {
+    auto *node = cast<llvm::MDNode>(operand.get());
+    aliasScopes.push_back(aliasScopeMapping.lookup(node));
+  }
+  // Return failure if one of the alias scope lookups failed.
+  if (llvm::is_contained(aliasScopes, nullptr))
+    return failure();
+  return aliasScopes;
+}
+
 LogicalResult ModuleImport::convertMetadata() {
   OpBuilder::InsertionGuard guard(builder);
   builder.setInsertionPointToEnd(mlirModule.getBody());
@@ -539,8 +632,12 @@ LogicalResult ModuleImport::convertMetadata() {
       if (aliasAnalysisNodes.TBAA)
         if (failed(processTBAAMetadata(aliasAnalysisNodes.TBAA)))
           return failure();
-
-      // TODO: Support noalias and scope metadata nodes.
+      if (aliasAnalysisNodes.Scope)
+        if (failed(processAliasScopeMetadata(aliasAnalysisNodes.Scope)))
+          return failure();
+      if (aliasAnalysisNodes.NoAlias)
+        if (failed(processAliasScopeMetadata(aliasAnalysisNodes.NoAlias)))
+          return failure();
     }
   }
   return success();

diff  --git a/mlir/test/Dialect/LLVMIR/invalid.mlir b/mlir/test/Dialect/LLVMIR/invalid.mlir
index 9d8499621638f..256a509049252 100644
--- a/mlir/test/Dialect/LLVMIR/invalid.mlir
+++ b/mlir/test/Dialect/LLVMIR/invalid.mlir
@@ -964,6 +964,28 @@ module {
 
 // -----
 
+module {
+  llvm.metadata @metadata {
+    llvm.access_group @group
+    // expected-error at below {{expected 'group' to reference a domain operation in the same region}}
+    llvm.alias_scope @scope { domain = @group }
+  }
+}
+
+// -----
+
+module {
+  llvm.metadata @metadata {
+    // expected-error at below {{expected 'domain' to reference a domain operation in the same region}}
+    llvm.alias_scope @scope { domain = @domain }
+  }
+  llvm.metadata @other_metadata {
+    llvm.alias_scope_domain @domain
+  }
+}
+
+// -----
+
 llvm.func @wmmaLoadOp_invalid_mem_space(%arg0: !llvm.ptr<i32, 5>, %arg1: i32) {
   // expected-error at +1 {{'nvvm.wmma.load' op expected source pointer in memory space 0, 1, 3}}
   %0 = nvvm.wmma.load %arg0, %arg1

diff  --git a/mlir/test/Target/LLVMIR/Import/import-failure.ll b/mlir/test/Target/LLVMIR/Import/import-failure.ll
index 3286d3b904001..5d79a82439c6c 100644
--- a/mlir/test/Target/LLVMIR/Import/import-failure.ll
+++ b/mlir/test/Target/LLVMIR/Import/import-failure.ll
@@ -572,3 +572,39 @@ define void @cond_br(i1 %arg) !prof !0 {
 }
 
 !0 = !{!"branch_weights", i32 64}
+
+; // -----
+
+; CHECK:      import-failure.ll
+; CHECK-SAME: error: unsupported alias scope node: ![[NODE:[0-9]+]] = distinct !{![[NODE]]}
+define void @alias_scope(ptr %arg1) {
+  %1 = load i32, ptr %arg1, !alias.scope !0
+  ret void
+}
+
+!0 = !{!0}
+
+; // -----
+
+; CHECK:      import-failure.ll
+; CHECK-SAME: error: unsupported alias scope node: ![[NODE:[0-9]+]] = distinct !{![[NODE]], !"The domain"}
+define void @alias_scope(ptr %arg1) {
+  %1 = load i32, ptr %arg1, !alias.scope !1
+  ret void
+}
+
+!0 = distinct !{!0, !"The domain"}
+!1 = !{!1, !0}
+
+; // -----
+
+; CHECK:      import-failure.ll
+; CHECK-SAME: error: unsupported alias domain node: ![[NODE:[0-9]+]] = distinct !{![[NODE]], ![[NODE]]}
+define void @alias_scope_domain(ptr %arg1) {
+  %1 = load i32, ptr %arg1, !alias.scope !2
+  ret void
+}
+
+!0 = distinct !{!0, !0}
+!1 = !{!1, !0}
+!2 = !{!1}

diff  --git a/mlir/test/Target/LLVMIR/Import/metadata-alias-scopes.ll b/mlir/test/Target/LLVMIR/Import/metadata-alias-scopes.ll
new file mode 100644
index 0000000000000..9db045dde27a7
--- /dev/null
+++ b/mlir/test/Target/LLVMIR/Import/metadata-alias-scopes.ll
@@ -0,0 +1,61 @@
+; RUN: mlir-translate -import-llvm -split-input-file %s | FileCheck %s
+
+; CHECK: llvm.metadata @__llvm_global_metadata {
+; CHECK:   llvm.alias_scope_domain @[[DOMAIN:.*]] {description = "The domain"}
+; CHECK:   llvm.alias_scope @[[$SCOPE0:.*]] {description = "The first scope", domain = @[[DOMAIN]]}
+; CHECK:   llvm.alias_scope @[[$SCOPE1:.*]] {domain = @[[DOMAIN]]}
+; CHECK:   llvm.alias_scope @[[$SCOPE2:.*]] {domain = @[[DOMAIN]]}
+; CHECK: }
+
+; CHECK-LABEL: llvm.func @alias_scope
+define void @alias_scope(ptr %arg1) {
+  ; CHECK: llvm.load
+  ; CHECK-SAME:  alias_scopes = [@__llvm_global_metadata::@[[$SCOPE0]]]
+  ; CHECK-SAME:  noalias_scopes = [@__llvm_global_metadata::@[[$SCOPE1]], @__llvm_global_metadata::@[[$SCOPE2]]]
+  %1 = load i32, ptr %arg1, !alias.scope !4, !noalias !7
+  ; CHECK: llvm.load
+  ; CHECK-SAME:  alias_scopes = [@__llvm_global_metadata::@[[$SCOPE1]]]
+  ; CHECK-SAME:  noalias_scopes = [@__llvm_global_metadata::@[[$SCOPE0]], @__llvm_global_metadata::@[[$SCOPE2]]]
+  %2 = load i32, ptr %arg1, !alias.scope !5, !noalias !8
+  ; CHECK: llvm.load
+  ; CHECK-SAME:  alias_scopes = [@__llvm_global_metadata::@[[$SCOPE2]]]
+  ; CHECK-SAME:  noalias_scopes = [@__llvm_global_metadata::@[[$SCOPE0]], @__llvm_global_metadata::@[[$SCOPE1]]]
+  %3 = load i32, ptr %arg1, !alias.scope !6, !noalias !9
+  ret void
+}
+
+!0 = distinct !{!0, !"The domain"}
+!1 = distinct !{!1, !0, !"The first scope"}
+!2 = distinct !{!2, !0}
+!3 = distinct !{!3, !0}
+!4 = !{!1}
+!5 = !{!2}
+!6 = !{!3}
+!7 = !{!2, !3}
+!8 = !{!1, !3}
+!9 = !{!1, !2}
+
+; // -----
+
+; CHECK: llvm.metadata @__llvm_global_metadata {
+; CHECK:   llvm.alias_scope_domain @[[DOMAIN0:.*]] {description = "The domain"}
+; CHECK:   llvm.alias_scope @[[$SCOPE0:.*]] {domain = @[[DOMAIN0]]}
+; CHECK:   llvm.alias_scope_domain @[[DOMAIN1:.*]]
+; CHECK:   llvm.alias_scope @[[$SCOPE1:.*]] {domain = @[[DOMAIN1]]}
+; CHECK: }
+
+; CHECK-LABEL: llvm.func @two_domains
+define void @two_domains(ptr %arg1) {
+  ; CHECK: llvm.load
+  ; CHECK-SAME:  alias_scopes = [@__llvm_global_metadata::@[[$SCOPE0]]]
+  ; CHECK-SAME:  noalias_scopes = [@__llvm_global_metadata::@[[$SCOPE1]]]
+  %1 = load i32, ptr %arg1, !alias.scope !4, !noalias !5
+  ret void
+}
+
+!0 = distinct !{!0, !"The domain"}
+!1 = distinct !{!1}
+!2 = !{!2, !0}
+!3 = !{!3, !1}
+!4 = !{!2}
+!5 = !{!3}


        


More information about the Mlir-commits mailing list