[MLIR][OpenMP] Add LLVM translation support for OpenMP UserDefinedMappers

This patch adds OpenMPToLLVMIRTranslation support for the OpenMP Declare Mapper directive.

Since both MLIR and Clang now support custom mappers, I've made the relative params required instead of optional as well.

Depends on #121005

Author: TIFitis

clang/lib/CodeGen/CGOpenMPRuntime.cpp

@@ -8889,8 +8889,8 @@ static void emitOffloadingArraysAndArgs(
     return MFunc;
   };
   OMPBuilder.emitOffloadingArraysAndArgs(
-      AllocaIP, CodeGenIP, Info, Info.RTArgs, CombinedInfo, IsNonContiguous,
-      ForEndCall, DeviceAddrCB, CustomMapperCB);
+      AllocaIP, CodeGenIP, Info, Info.RTArgs, CombinedInfo, CustomMapperCB,
+      IsNonContiguous, ForEndCall, DeviceAddrCB);
 }
 
 /// Check for inner distribute directive.
@@ -9099,9 +9099,10 @@ void CGOpenMPRuntime::emitUserDefinedMapper(const OMPDeclareMapperDecl *D,
   CGM.getCXXABI().getMangleContext().mangleCanonicalTypeName(Ty, Out);
   std::string Name = getName({"omp_mapper", TyStr, D->getName()});
 
-  auto *NewFn = OMPBuilder.emitUserDefinedMapper(PrivatizeAndGenMapInfoCB,
-                                                 ElemTy, Name, CustomMapperCB);
-  UDMMap.try_emplace(D, NewFn);
+  llvm::Expected<llvm::Function *> NewFn = OMPBuilder.emitUserDefinedMapper(
+      PrivatizeAndGenMapInfoCB, ElemTy, Name, CustomMapperCB);
+  assert(NewFn && "Unexpected error in emitUserDefinedMapper");
+  UDMMap.try_emplace(D, *NewFn);
   if (CGF)
     FunctionUDMMap[CGF->CurFn].push_back(D);
 }

llvm/include/llvm/Frontend/OpenMP/OMPIRBuilder.h

@@ -2399,6 +2399,7 @@ class OpenMPIRBuilder {
                                    CurInfo.NonContigInfo.Strides.end());
     }
   };
+  using MapInfosOrErrorTy = Expected<MapInfosTy &>;
 
   /// Callback function type for functions emitting the host fallback code that
   /// is executed when the kernel launch fails. It takes an insertion point as
@@ -2475,9 +2476,9 @@ class OpenMPIRBuilder {
   /// including base pointers, pointers, sizes, map types, user-defined mappers.
   void emitOffloadingArrays(
       InsertPointTy AllocaIP, InsertPointTy CodeGenIP, MapInfosTy &CombinedInfo,
-      TargetDataInfo &Info, bool IsNonContiguous = false,
-      function_ref<void(unsigned int, Value *)> DeviceAddrCB = nullptr,
-      function_ref<Value *(unsigned int)> CustomMapperCB = nullptr);
+      TargetDataInfo &Info, function_ref<Value *(unsigned int)> CustomMapperCB,
+      bool IsNonContiguous = false,
+      function_ref<void(unsigned int, Value *)> DeviceAddrCB = nullptr);
 
   /// Allocates memory for and populates the arrays required for offloading
   /// (offload_{baseptrs|ptrs|mappers|sizes|maptypes|mapnames}). Then, it
@@ -2488,9 +2489,9 @@ class OpenMPIRBuilder {
   void emitOffloadingArraysAndArgs(
       InsertPointTy AllocaIP, InsertPointTy CodeGenIP, TargetDataInfo &Info,
       TargetDataRTArgs &RTArgs, MapInfosTy &CombinedInfo,
+      function_ref<Value *(unsigned int)> CustomMapperCB,
       bool IsNonContiguous = false, bool ForEndCall = false,
-      function_ref<void(unsigned int, Value *)> DeviceAddrCB = nullptr,
-      function_ref<Value *(unsigned int)> CustomMapperCB = nullptr);
+      function_ref<void(unsigned int, Value *)> DeviceAddrCB = nullptr);
 
   /// Creates offloading entry for the provided entry ID \a ID, address \a
   /// Addr, size \a Size, and flags \a Flags.
@@ -2950,12 +2951,12 @@ class OpenMPIRBuilder {
   /// \param FuncName Optional param to specify mapper function name.
   /// \param CustomMapperCB Optional callback to generate code related to
   /// custom mappers.
-  Function *emitUserDefinedMapper(
-      function_ref<MapInfosTy &(InsertPointTy CodeGenIP, llvm::Value *PtrPHI,
-                                llvm::Value *BeginArg)>
+  Expected<Function *> emitUserDefinedMapper(
+      function_ref<MapInfosOrErrorTy(
+          InsertPointTy CodeGenIP, llvm::Value *PtrPHI, llvm::Value *BeginArg)>
           PrivAndGenMapInfoCB,
       llvm::Type *ElemTy, StringRef FuncName,
-      function_ref<bool(unsigned int, Function **)> CustomMapperCB = nullptr);
+      function_ref<bool(unsigned int, Function **)> CustomMapperCB);
 
   /// Generator for '#omp target data'
   ///
@@ -2969,21 +2970,21 @@ class OpenMPIRBuilder {
   /// \param IfCond Value which corresponds to the if clause condition.
   /// \param Info Stores all information realted to the Target Data directive.
   /// \param GenMapInfoCB Callback that populates the MapInfos and returns.
+  /// \param CustomMapperCB Callback to generate code related to
+  /// custom mappers.
   /// \param BodyGenCB Optional Callback to generate the region code.
   /// \param DeviceAddrCB Optional callback to generate code related to
   /// use_device_ptr and use_device_addr.
-  /// \param CustomMapperCB Optional callback to generate code related to
-  /// custom mappers.
   InsertPointOrErrorTy createTargetData(
       const LocationDescription &Loc, InsertPointTy AllocaIP,
       InsertPointTy CodeGenIP, Value *DeviceID, Value *IfCond,
       TargetDataInfo &Info, GenMapInfoCallbackTy GenMapInfoCB,
+      function_ref<Value *(unsigned int)> CustomMapperCB,
       omp::RuntimeFunction *MapperFunc = nullptr,
       function_ref<InsertPointOrErrorTy(InsertPointTy CodeGenIP,
                                         BodyGenTy BodyGenType)>
           BodyGenCB = nullptr,
       function_ref<void(unsigned int, Value *)> DeviceAddrCB = nullptr,
-      function_ref<Value *(unsigned int)> CustomMapperCB = nullptr,
       Value *SrcLocInfo = nullptr);
 
   using TargetBodyGenCallbackTy = function_ref<InsertPointOrErrorTy(
@@ -2999,6 +3000,7 @@ class OpenMPIRBuilder {
   /// \param IsOffloadEntry whether it is an offload entry.
   /// \param CodeGenIP The insertion point where the call to the outlined
   ///        function should be emitted.
+  /// \param Info Stores all information realted to the Target directive.
   /// \param EntryInfo The entry information about the function.
   /// \param DefaultAttrs Structure containing the default attributes, including
   ///        numbers of threads and teams to launch the kernel with.
@@ -3010,20 +3012,23 @@ class OpenMPIRBuilder {
   /// \param BodyGenCB Callback that will generate the region code.
   /// \param ArgAccessorFuncCB Callback that will generate accessors
   ///        instructions for passed in target arguments where neccessary
+  /// \param CustomMapperCB Callback to generate code related to
+  /// custom mappers.
   /// \param Dependencies A vector of DependData objects that carry
   ///        dependency information as passed in the depend clause
   /// \param HasNowait Whether the target construct has a `nowait` clause or
   ///        not.
   InsertPointOrErrorTy createTarget(
       const LocationDescription &Loc, bool IsOffloadEntry,
       OpenMPIRBuilder::InsertPointTy AllocaIP,
-      OpenMPIRBuilder::InsertPointTy CodeGenIP,
+      OpenMPIRBuilder::InsertPointTy CodeGenIP, TargetDataInfo &Info,
       TargetRegionEntryInfo &EntryInfo,
       const TargetKernelDefaultAttrs &DefaultAttrs,
       const TargetKernelRuntimeAttrs &RuntimeAttrs, Value *IfCond,
       SmallVectorImpl<Value *> &Inputs, GenMapInfoCallbackTy GenMapInfoCB,
       TargetBodyGenCallbackTy BodyGenCB,
       TargetGenArgAccessorsCallbackTy ArgAccessorFuncCB,
+      function_ref<Value *(unsigned int)> CustomMapperCB,
       SmallVector<DependData> Dependencies = {}, bool HasNowait = false);
 
   /// Returns __kmpc_for_static_init_* runtime function for the specified

llvm/lib/Frontend/OpenMP/OMPIRBuilder.cpp

@@ -6549,12 +6549,12 @@ OpenMPIRBuilder::InsertPointOrErrorTy OpenMPIRBuilder::createTargetData(
     const LocationDescription &Loc, InsertPointTy AllocaIP,
     InsertPointTy CodeGenIP, Value *DeviceID, Value *IfCond,
     TargetDataInfo &Info, GenMapInfoCallbackTy GenMapInfoCB,
+    function_ref<Value *(unsigned int)> CustomMapperCB,
     omp::RuntimeFunction *MapperFunc,
     function_ref<InsertPointOrErrorTy(InsertPointTy CodeGenIP,
                                       BodyGenTy BodyGenType)>
         BodyGenCB,
-    function_ref<void(unsigned int, Value *)> DeviceAddrCB,
-    function_ref<Value *(unsigned int)> CustomMapperCB, Value *SrcLocInfo) {
+    function_ref<void(unsigned int, Value *)> DeviceAddrCB, Value *SrcLocInfo) {
   if (!updateToLocation(Loc))
     return InsertPointTy();
 
@@ -6580,8 +6580,8 @@ OpenMPIRBuilder::InsertPointOrErrorTy OpenMPIRBuilder::createTargetData(
                           InsertPointTy CodeGenIP) -> Error {
     MapInfo = &GenMapInfoCB(Builder.saveIP());
     emitOffloadingArrays(AllocaIP, Builder.saveIP(), *MapInfo, Info,
-                         /*IsNonContiguous=*/true, DeviceAddrCB,
-                         CustomMapperCB);
+                         CustomMapperCB,
+                         /*IsNonContiguous=*/true, DeviceAddrCB);
 
     TargetDataRTArgs RTArgs;
     emitOffloadingArraysArgument(Builder, RTArgs, Info);
@@ -7394,24 +7394,26 @@ OpenMPIRBuilder::InsertPointOrErrorTy OpenMPIRBuilder::emitTargetTask(
 
 void OpenMPIRBuilder::emitOffloadingArraysAndArgs(
     InsertPointTy AllocaIP, InsertPointTy CodeGenIP, TargetDataInfo &Info,
-    TargetDataRTArgs &RTArgs, MapInfosTy &CombinedInfo, bool IsNonContiguous,
-    bool ForEndCall, function_ref<void(unsigned int, Value *)> DeviceAddrCB,
-    function_ref<Value *(unsigned int)> CustomMapperCB) {
-  emitOffloadingArrays(AllocaIP, CodeGenIP, CombinedInfo, Info, IsNonContiguous,
-                       DeviceAddrCB, CustomMapperCB);
+    TargetDataRTArgs &RTArgs, MapInfosTy &CombinedInfo,
+    function_ref<Value *(unsigned int)> CustomMapperCB, bool IsNonContiguous,
+    bool ForEndCall, function_ref<void(unsigned int, Value *)> DeviceAddrCB) {
+  emitOffloadingArrays(AllocaIP, CodeGenIP, CombinedInfo, Info, CustomMapperCB,
+                       IsNonContiguous, DeviceAddrCB);
   emitOffloadingArraysArgument(Builder, RTArgs, Info, ForEndCall);
 }
 
 static void
 emitTargetCall(OpenMPIRBuilder &OMPBuilder, IRBuilderBase &Builder,
                OpenMPIRBuilder::InsertPointTy AllocaIP,
+               OpenMPIRBuilder::TargetDataInfo &Info,
                const OpenMPIRBuilder::TargetKernelDefaultAttrs &DefaultAttrs,
                const OpenMPIRBuilder::TargetKernelRuntimeAttrs &RuntimeAttrs,
                Value *IfCond, Function *OutlinedFn, Constant *OutlinedFnID,
                SmallVectorImpl<Value *> &Args,
                OpenMPIRBuilder::GenMapInfoCallbackTy GenMapInfoCB,
-               SmallVector<llvm::OpenMPIRBuilder::DependData> Dependencies = {},
-               bool HasNoWait = false) {
+               function_ref<Value *(unsigned int)> CustomMapperCB,
+               SmallVector<llvm::OpenMPIRBuilder::DependData> Dependencies,
+               bool HasNoWait) {
   // Generate a function call to the host fallback implementation of the target
   // region. This is called by the host when no offload entry was generated for
   // the target region and when the offloading call fails at runtime.
@@ -7489,7 +7491,7 @@ emitTargetCall(OpenMPIRBuilder &OMPBuilder, IRBuilderBase &Builder,
     OpenMPIRBuilder::MapInfosTy &MapInfo = GenMapInfoCB(Builder.saveIP());
     OpenMPIRBuilder::TargetDataRTArgs RTArgs;
     OMPBuilder.emitOffloadingArraysAndArgs(AllocaIP, Builder.saveIP(), Info,
-                                           RTArgs, MapInfo,
+                                           RTArgs, MapInfo, CustomMapperCB,
                                            /*IsNonContiguous=*/true,
                                            /*ForEndCall=*/false);
 
@@ -7593,12 +7595,14 @@ emitTargetCall(OpenMPIRBuilder &OMPBuilder, IRBuilderBase &Builder,
 
 OpenMPIRBuilder::InsertPointOrErrorTy OpenMPIRBuilder::createTarget(
     const LocationDescription &Loc, bool IsOffloadEntry, InsertPointTy AllocaIP,
-    InsertPointTy CodeGenIP, TargetRegionEntryInfo &EntryInfo,
+    InsertPointTy CodeGenIP, TargetDataInfo &Info,
+    TargetRegionEntryInfo &EntryInfo,
     const TargetKernelDefaultAttrs &DefaultAttrs,
     const TargetKernelRuntimeAttrs &RuntimeAttrs, Value *IfCond,
-    SmallVectorImpl<Value *> &Args, GenMapInfoCallbackTy GenMapInfoCB,
+    SmallVectorImpl<Value *> &Inputs, GenMapInfoCallbackTy GenMapInfoCB,
     OpenMPIRBuilder::TargetBodyGenCallbackTy CBFunc,
     OpenMPIRBuilder::TargetGenArgAccessorsCallbackTy ArgAccessorFuncCB,
+    function_ref<Value *(unsigned int)> CustomMapperCB,
     SmallVector<DependData> Dependencies, bool HasNowait) {
 
   if (!updateToLocation(Loc))
@@ -7613,16 +7617,16 @@ OpenMPIRBuilder::InsertPointOrErrorTy OpenMPIRBuilder::createTarget(
   // and ArgAccessorFuncCB
   if (Error Err = emitTargetOutlinedFunction(
           *this, Builder, IsOffloadEntry, EntryInfo, DefaultAttrs, OutlinedFn,
-          OutlinedFnID, Args, CBFunc, ArgAccessorFuncCB))
+          OutlinedFnID, Inputs, CBFunc, ArgAccessorFuncCB))
     return Err;
 
   // If we are not on the target device, then we need to generate code
   // to make a remote call (offload) to the previously outlined function
   // that represents the target region. Do that now.
   if (!Config.isTargetDevice())
-    emitTargetCall(*this, Builder, AllocaIP, DefaultAttrs, RuntimeAttrs, IfCond,
-                   OutlinedFn, OutlinedFnID, Args, GenMapInfoCB, Dependencies,
-                   HasNowait);
+    emitTargetCall(*this, Builder, AllocaIP, Info, DefaultAttrs, RuntimeAttrs,
+                   IfCond, OutlinedFn, OutlinedFnID, Inputs, GenMapInfoCB,
+                   CustomMapperCB, Dependencies, HasNowait);
   return Builder.saveIP();
 }
 
@@ -7947,9 +7951,9 @@ void OpenMPIRBuilder::emitUDMapperArrayInitOrDel(
       OffloadingArgs);
 }
 
-Function *OpenMPIRBuilder::emitUserDefinedMapper(
-    function_ref<MapInfosTy &(InsertPointTy CodeGenIP, llvm::Value *PtrPHI,
-                              llvm::Value *BeginArg)>
+Expected<Function *> OpenMPIRBuilder::emitUserDefinedMapper(
+    function_ref<MapInfosOrErrorTy(InsertPointTy CodeGenIP, llvm::Value *PtrPHI,
+                                   llvm::Value *BeginArg)>
         GenMapInfoCB,
     Type *ElemTy, StringRef FuncName,
     function_ref<bool(unsigned int, Function **)> CustomMapperCB) {
@@ -8023,7 +8027,9 @@ Function *OpenMPIRBuilder::emitUserDefinedMapper(
   PtrPHI->addIncoming(PtrBegin, HeadBB);
 
   // Get map clause information. Fill up the arrays with all mapped variables.
-  MapInfosTy &Info = GenMapInfoCB(Builder.saveIP(), PtrPHI, BeginIn);
+  MapInfosOrErrorTy Info = GenMapInfoCB(Builder.saveIP(), PtrPHI, BeginIn);
+  if (!Info)
+    return Info.takeError();
 
   // Call the runtime API __tgt_mapper_num_components to get the number of
   // pre-existing components.
@@ -8035,20 +8041,20 @@ Function *OpenMPIRBuilder::emitUserDefinedMapper(
       Builder.CreateShl(PreviousSize, Builder.getInt64(getFlagMemberOffset()));
 
   // Fill up the runtime mapper handle for all components.
-  for (unsigned I = 0; I < Info.BasePointers.size(); ++I) {
+  for (unsigned I = 0; I < Info->BasePointers.size(); ++I) {
     Value *CurBaseArg =
-        Builder.CreateBitCast(Info.BasePointers[I], Builder.getPtrTy());
+        Builder.CreateBitCast(Info->BasePointers[I], Builder.getPtrTy());
     Value *CurBeginArg =
-        Builder.CreateBitCast(Info.Pointers[I], Builder.getPtrTy());
-    Value *CurSizeArg = Info.Sizes[I];
-    Value *CurNameArg = Info.Names.size()
-                            ? Info.Names[I]
+        Builder.CreateBitCast(Info->Pointers[I], Builder.getPtrTy());
+    Value *CurSizeArg = Info->Sizes[I];
+    Value *CurNameArg = Info->Names.size()
+                            ? Info->Names[I]
                             : Constant::getNullValue(Builder.getPtrTy());
 
     // Extract the MEMBER_OF field from the map type.
     Value *OriMapType = Builder.getInt64(
         static_cast<std::underlying_type_t<OpenMPOffloadMappingFlags>>(
-            Info.Types[I]));
+            Info->Types[I]));
     Value *MemberMapType =
         Builder.CreateNUWAdd(OriMapType, ShiftedPreviousSize);
 
@@ -8169,9 +8175,9 @@ Function *OpenMPIRBuilder::emitUserDefinedMapper(
 
 void OpenMPIRBuilder::emitOffloadingArrays(
     InsertPointTy AllocaIP, InsertPointTy CodeGenIP, MapInfosTy &CombinedInfo,
-    TargetDataInfo &Info, bool IsNonContiguous,
-    function_ref<void(unsigned int, Value *)> DeviceAddrCB,
-    function_ref<Value *(unsigned int)> CustomMapperCB) {
+    TargetDataInfo &Info, function_ref<Value *(unsigned int)> CustomMapperCB,
+    bool IsNonContiguous,
+    function_ref<void(unsigned int, Value *)> DeviceAddrCB) {
 
   // Reset the array information.
   Info.clearArrayInfo();