[OpenMP][OpenMPIRBuilder] Migrate loadOffloadInfoMetadata from clang to OMPIRbuilder

[TIFitis]

Summary

This patch moves the implementation of the loadOffloadInfoMetadata to the OMPIRbuilder.

[jdoerfert]

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

2167

Why is this in llvm namespace? This should be qualified further, e.g. part of the OMPIRBuilder. Also, no llvm::

llvm/lib/Frontend/OpenMP/OMPIRBuilder.cpp

4717

Why do we call it if isDevice is false? Module should be available to the IRBuilder.

4765

No llvm::. Put "omp_offload.info" into a global constant, either in OMPIRBuilder or OMPConstants.

[TIFitis]

Moved loadOffloadInfoMetadata inside OpenMPIRBuilder class.

[TIFitis]

llvm/lib/Frontend/OpenMP/OMPIRBuilder.cpp

4717

loadOffloadInfoMetadata is called from clang with a different Module generated using parseBitcodeFile. I've checked that the module available from OMPIRBuilder and the one passed by clang are different and cause errors.

[jdoerfert]

@jsjodin Can you take a look and accept once it looks ok.

llvm/lib/Frontend/OpenMP/OMPIRBuilder.cpp

4717

I see. Then document this explicitly in the doxygen comment of the declaration, please. Also check isDevice at the call site.

[TIFitis]

Added doxygen comment to explain why module must be passed to OMPIRBuilder.

[TIFitis]

llvm/lib/Frontend/OpenMP/OMPIRBuilder.cpp

4717

Added doxygen comment. isDevice is checked at call site through CGM.getLangOpts().OpenMPIsDevice.

[TIFitis]

Removed isDevice() check from function definition.

[TIFitis]

Fix build errors

[jsjodin]

llvm/lib/Frontend/OpenMP/OMPIRBuilder.cpp

4712

isDevice must be true (add assertion at the call site) remove the parameter, and the assertions in this function. Document that this function is only intended to be used with device code generation.

[jdoerfert]

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

1685

Drive by, add doxygen documentation to all methods + members please.

[TIFitis]

Removed isDevice from parameters. Added documentation.

[TIFitis]

llvm/lib/Frontend/OpenMP/OMPIRBuilder.cpp

4712

I've removed isDevice as a parameter. At the call site, isDevice is checked inside an if condition and it returns on false, thus I haven't added the assertion back at the call site.

[TIFitis]

Fixed comments

[jsjodin]

@jdoerfert do you have any other comments?

clang/lib/CodeGen/CGOpenMPRuntime.cpp

 //===----- CGOpenMPRuntime.cpp - Interface to OpenMP Runtimes -------------===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 //
void CGOpenMPRuntime::loadOffloadInfoMetadata() {
   if (auto EC = ME.getError()) {
     unsigned DiagID = CGM.getDiags().getCustomDiagID(
         DiagnosticsEngine::Error, "Unable to parse host IR file '%0':'%1'");
     CGM.getDiags().Report(DiagID)
         << CGM.getLangOpts().OMPHostIRFile << EC.message();
     return;
   }
 
-  llvm::NamedMDNode *MD = ME.get()->getNamedMetadata("omp_offload.info");
-  if (!MD)
-    return;
-
-  for (llvm::MDNode *MN : MD->operands()) {
-    auto &&GetMDInt = [MN](unsigned Idx) {
-      auto *V = cast<llvm::ConstantAsMetadata>(MN->getOperand(Idx));
-      return cast<llvm::ConstantInt>(V->getValue())->getZExtValue();
-    };
-
-    auto &&GetMDString = [MN](unsigned Idx) {
-      auto *V = cast<llvm::MDString>(MN->getOperand(Idx));
-      return V->getString();
-    };
-
-    switch (GetMDInt(0)) {
-    default:
-      llvm_unreachable("Unexpected metadata!");
-      break;
-    case llvm::OffloadEntriesInfoManager::OffloadEntryInfo::
-        OffloadingEntryInfoTargetRegion: {
-      assert(CGM.getLangOpts().OpenMPIsDevice && "Initialization of entries is "
-                                                 "only required for the "
-                                                 "device code generation.");
-      llvm::TargetRegionEntryInfo EntryInfo(/*ParentName=*/GetMDString(3),
-                                            /*DeviceID=*/GetMDInt(1),
-                                            /*FileID=*/GetMDInt(2),
-                                            /*Line=*/GetMDInt(4));
-      OffloadEntriesInfoManager.initializeTargetRegionEntryInfo(
-          EntryInfo, /*Order=*/GetMDInt(5));
-      break;
-    }
-    case llvm::OffloadEntriesInfoManager::OffloadEntryInfo::
-        OffloadingEntryInfoDeviceGlobalVar:
-      assert(CGM.getLangOpts().OpenMPIsDevice && "Initialization of entries is "
-                                                 "only required for the "
-                                                 "device code generation.");
-      OffloadEntriesInfoManager.initializeDeviceGlobalVarEntryInfo(
-          /*MangledName=*/GetMDString(1),
-          static_cast<
-              llvm::OffloadEntriesInfoManager::OMPTargetGlobalVarEntryKind>(
-              /*Flags=*/GetMDInt(2)),
-          /*Order=*/GetMDInt(3));
-      break;
-    }
-  }
+  llvm::loadOffloadInfoMetadata(*ME.get(), OffloadEntriesInfoManager, CGM.getLangOpts().OpenMPIsDevice);
 }
 
 void CGOpenMPRuntime::emitKmpRoutineEntryT(QualType KmpInt32Ty) {
   if (!KmpRoutineEntryPtrTy) {
     // Build typedef kmp_int32 (* kmp_routine_entry_t)(kmp_int32, void *); type.
     ASTContext &C = CGM.getContext();
     QualType KmpRoutineEntryTyArgs[] = {KmpInt32Ty, C.VoidPtrTy};
     FunctionProtoType::ExtProtoInfo EPI;

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

 //===- IR/OpenMPIRBuilder.h - OpenMP encoding builder for LLVM IR - C++ -*-===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 //
public:
   ///
   /// \returns The CanonicalLoopInfo that represents the emitted loop.
   CanonicalLoopInfo *createLoopSkeleton(DebugLoc DL, Value *TripCount,
                                         Function *F,
                                         BasicBlock *PreInsertBefore,
                                         BasicBlock *PostInsertBefore,
                                         const Twine &Name = {});
 };
 
 /// Data structure to contain the information needed to uniquely identify
 /// a target entry.
 struct TargetRegionEntryInfo {
   std::string ParentName;
   unsigned DeviceID;
   unsigned FileID;
   unsigned Line;
 
public:
   /// Consistency self-check.
   void assertOK() const;
 
   /// Invalidate this loop. That is, the underlying IR does not fulfill the
   /// requirements of an OpenMP canonical loop anymore.
   void invalidate();
 };
 
+/// Loads all the offload entries information from the host IR
+/// metadata.
+void loadOffloadInfoMetadata(
+    Module &M, llvm::OffloadEntriesInfoManager &OffloadEntriesInfoManager,
+    bool isDevice);
+
 } // end namespace llvm
 
 #endif // LLVM_FRONTEND_OPENMP_OMPIRBUILDER_H

llvm/lib/Frontend/OpenMP/OMPIRBuilder.cpp

 //===- OpenMPIRBuilder.cpp - Builder for LLVM-IR for OpenMP directives ----===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 /// \file
OS << "__omp_offloading" << llvm::format("_%x", DeviceID)
      << llvm::format("_%x_", FileID) << ParentName << "_l" << Line;
 }
 
 void TargetRegionEntryInfo::getTargetRegionEntryFnName(
     SmallVectorImpl<char> &Name) {
   getTargetRegionEntryFnName(Name, ParentName, DeviceID, FileID, Line);
 }
 
+/// Loads all the offload entries information from the host IR
+/// metadata.
+void llvm::loadOffloadInfoMetadata(
+    Module &M, OffloadEntriesInfoManager &OffloadEntriesInfoManager,
+    bool isDevice) {
+  // If we are in target mode, load the metadata from the host IR. This code has
+  // to match the metadaata creation in createOffloadEntriesAndInfoMetadata().
+
+  if (!isDevice)
+    return;
+
+  llvm::NamedMDNode *MD = M.getNamedMetadata("omp_offload.info");
+  if (!MD)
+    return;
+
+  for (llvm::MDNode *MN : MD->operands()) {
+    auto &&GetMDInt = [MN](unsigned Idx) {
+      auto *V = cast<llvm::ConstantAsMetadata>(MN->getOperand(Idx));
+      return cast<llvm::ConstantInt>(V->getValue())->getZExtValue();
+    };
+
+    auto &&GetMDString = [MN](unsigned Idx) {
+      auto *V = cast<llvm::MDString>(MN->getOperand(Idx));
+      return V->getString();
+    };
+
+    switch (GetMDInt(0)) {
+    default:
+      llvm_unreachable("Unexpected metadata!");
+      break;
+    case llvm::OffloadEntriesInfoManager::OffloadEntryInfo::
+        OffloadingEntryInfoTargetRegion: {
+      assert(isDevice && "Initialization of entries is "
+                                                 "only required for the "
+                                                 "device code generation.");
+      llvm::TargetRegionEntryInfo EntryInfo(/*ParentName=*/GetMDString(3),
+                                            /*DeviceID=*/GetMDInt(1),
+                                            /*FileID=*/GetMDInt(2),
+                                            /*Line=*/GetMDInt(4));
+      OffloadEntriesInfoManager.initializeTargetRegionEntryInfo(
+          EntryInfo, /*Order=*/GetMDInt(5));
+      break;
+    }
+    case llvm::OffloadEntriesInfoManager::OffloadEntryInfo::
+        OffloadingEntryInfoDeviceGlobalVar:
+      assert(isDevice && "Initialization of entries is "
+                                                 "only required for the "
+                                                 "device code generation.");
+      OffloadEntriesInfoManager.initializeDeviceGlobalVarEntryInfo(
+          /*MangledName=*/GetMDString(1),
+          static_cast<
+              llvm::OffloadEntriesInfoManager::OMPTargetGlobalVarEntryKind>(
+              /*Flags=*/GetMDInt(2)),
+          /*Order=*/GetMDInt(3));
+      break;
+    }
+  }
+}
+
 bool OffloadEntriesInfoManager::empty() const {
   return OffloadEntriesTargetRegion.empty() &&
          OffloadEntriesDeviceGlobalVar.empty();
 }
 
 /// Initialize target region entry.
 void OffloadEntriesInfoManager::initializeTargetRegionEntryInfo(
     const TargetRegionEntryInfo &EntryInfo, unsigned Order) {