[llvm][mlir][OMPIRBuilder] Translate omp.single's copyprivate

luporl · luporl · commit 75fde1a3fdbb · 2024-02-22T20:26:01.000Z
Use the new copyprivate list from omp.single to emit calls to __kmpc_copyprivate, during the creation of the single operation in OMPIRBuilder. This is patch 4 of 4, to add support for COPYPRIVATE in Flang. Original PR: llvm#73128
diff --git a/llvm/include/llvm/Frontend/OpenMP/OMPIRBuilder.h b/llvm/include/llvm/Frontend/OpenMP/OMPIRBuilder.h
@@ -1830,12 +1830,16 @@ class OpenMPIRBuilder {
   /// \param FiniCB Callback to finalize variable copies.
   /// \param IsNowait If false, a barrier is emitted.
   /// \param DidIt Local variable used as a flag to indicate 'single' thread
+  /// \param CPVars copyprivate variables.
+  /// \param CPFuncs copy functions to use for each copyprivate variable.
   ///
   /// \returns The insertion position *after* the single call.
   InsertPointTy createSingle(const LocationDescription &Loc,
                              BodyGenCallbackTy BodyGenCB,
                              FinalizeCallbackTy FiniCB, bool IsNowait,
-                             llvm::Value *DidIt);
+                             llvm::Value *DidIt,
+                             ArrayRef<llvm::Value *> CPVars = {},
+                             ArrayRef<llvm::Function *> CPFuncs = {});
 
   /// Generator for '#omp master'
   ///
diff --git a/llvm/lib/Frontend/OpenMP/OMPIRBuilder.cpp b/llvm/lib/Frontend/OpenMP/OMPIRBuilder.cpp
@@ -4002,7 +4002,8 @@ OpenMPIRBuilder::createCopyPrivate(const LocationDescription &Loc,
 
 OpenMPIRBuilder::InsertPointTy OpenMPIRBuilder::createSingle(
     const LocationDescription &Loc, BodyGenCallbackTy BodyGenCB,
-    FinalizeCallbackTy FiniCB, bool IsNowait, llvm::Value *DidIt) {
+    FinalizeCallbackTy FiniCB, bool IsNowait, llvm::Value *DidIt,
+    ArrayRef<llvm::Value *> CPVars, ArrayRef<llvm::Function *> CPFuncs) {
 
   if (!updateToLocation(Loc))
     return Loc.IP;
@@ -4025,17 +4026,33 @@ OpenMPIRBuilder::InsertPointTy OpenMPIRBuilder::createSingle(
   Function *ExitRTLFn = getOrCreateRuntimeFunctionPtr(OMPRTL___kmpc_end_single);
   Instruction *ExitCall = Builder.CreateCall(ExitRTLFn, Args);
 
+  auto FiniCBWrapper = [&](InsertPointTy IP) {
+    FiniCB(IP);
+
+    if (DidIt)
+      Builder.CreateStore(Builder.getInt32(1), DidIt);
+  };
+
   // generates the following:
   // if (__kmpc_single()) {
   //		.... single region ...
   // 		__kmpc_end_single
   // }
+  // __kmpc_copyprivate
   // __kmpc_barrier
 
-  EmitOMPInlinedRegion(OMPD, EntryCall, ExitCall, BodyGenCB, FiniCB,
+  EmitOMPInlinedRegion(OMPD, EntryCall, ExitCall, BodyGenCB, FiniCBWrapper,
                        /*Conditional*/ true,
                        /*hasFinalize*/ true);
-  if (!IsNowait)
+
+  if (DidIt) {
+    for (size_t I = 0, E = CPVars.size(); I < E; ++I)
+      // NOTE BufSize is currently unused, so just pass 0.
+      createCopyPrivate(LocationDescription(Builder.saveIP(), Loc.DL),
+                        /*BufSize=*/ConstantInt::get(Int64, 0), CPVars[I],
+                        CPFuncs[I], DidIt);
+    // NOTE __kmpc_copyprivate already inserts a barrier
+  } else if (!IsNowait)
     createBarrier(LocationDescription(Builder.saveIP(), Loc.DL),
                   omp::Directive::OMPD_unknown, /* ForceSimpleCall */ false,
                   /* CheckCancelFlag */ false);
diff --git a/llvm/unittests/Frontend/OpenMPIRBuilderTest.cpp b/llvm/unittests/Frontend/OpenMPIRBuilderTest.cpp
@@ -3464,6 +3464,117 @@ TEST_F(OpenMPIRBuilderTest, SingleDirectiveNowait) {
   EXPECT_EQ(ExitBarrier, nullptr);
 }
 
+TEST_F(OpenMPIRBuilderTest, SingleDirectiveCopyPrivate) {
+  using InsertPointTy = OpenMPIRBuilder::InsertPointTy;
+  OpenMPIRBuilder OMPBuilder(*M);
+  OMPBuilder.initialize();
+  F->setName("func");
+  IRBuilder<> Builder(BB);
+
+  OpenMPIRBuilder::LocationDescription Loc({Builder.saveIP(), DL});
+
+  AllocaInst *PrivAI = nullptr;
+
+  BasicBlock *EntryBB = nullptr;
+  BasicBlock *ThenBB = nullptr;
+
+  Value *CPVar = Builder.CreateAlloca(F->arg_begin()->getType());
+  Builder.CreateStore(F->arg_begin(), CPVar);
+
+  FunctionType *CopyFuncTy = FunctionType::get(
+      Builder.getVoidTy(), {Builder.getPtrTy(), Builder.getPtrTy()}, false);
+  Function *CopyFunc =
+      Function::Create(CopyFuncTy, Function::PrivateLinkage, "copy_var", *M);
+
+  Value *DidIt = Builder.CreateAlloca(Type::getInt32Ty(Builder.getContext()));
+
+  auto BodyGenCB = [&](InsertPointTy AllocaIP, InsertPointTy CodeGenIP) {
+    if (AllocaIP.isSet())
+      Builder.restoreIP(AllocaIP);
+    else
+      Builder.SetInsertPoint(&*(F->getEntryBlock().getFirstInsertionPt()));
+    PrivAI = Builder.CreateAlloca(F->arg_begin()->getType());
+    Builder.CreateStore(F->arg_begin(), PrivAI);
+
+    llvm::BasicBlock *CodeGenIPBB = CodeGenIP.getBlock();
+    llvm::Instruction *CodeGenIPInst = &*CodeGenIP.getPoint();
+    EXPECT_EQ(CodeGenIPBB->getTerminator(), CodeGenIPInst);
+
+    Builder.restoreIP(CodeGenIP);
+
+    // collect some info for checks later
+    ThenBB = Builder.GetInsertBlock();
+    EntryBB = ThenBB->getUniquePredecessor();
+
+    // simple instructions for body
+    Value *PrivLoad =
+        Builder.CreateLoad(PrivAI->getAllocatedType(), PrivAI, "local.use");
+    Builder.CreateICmpNE(F->arg_begin(), PrivLoad);
+  };
+
+  auto FiniCB = [&](InsertPointTy IP) {
+    BasicBlock *IPBB = IP.getBlock();
+    EXPECT_NE(IPBB->end(), IP.getPoint());
+  };
+
+  Builder.restoreIP(OMPBuilder.createSingle(Builder, BodyGenCB, FiniCB,
+                                            /*IsNowait*/ false, DidIt, {CPVar},
+                                            {CopyFunc}));
+  Value *EntryBBTI = EntryBB->getTerminator();
+  EXPECT_NE(EntryBBTI, nullptr);
+  EXPECT_TRUE(isa<BranchInst>(EntryBBTI));
+  BranchInst *EntryBr = cast<BranchInst>(EntryBB->getTerminator());
+  EXPECT_TRUE(EntryBr->isConditional());
+  EXPECT_EQ(EntryBr->getSuccessor(0), ThenBB);
+  BasicBlock *ExitBB = ThenBB->getUniqueSuccessor();
+  EXPECT_EQ(EntryBr->getSuccessor(1), ExitBB);
+
+  CmpInst *CondInst = cast<CmpInst>(EntryBr->getCondition());
+  EXPECT_TRUE(isa<CallInst>(CondInst->getOperand(0)));
+
+  CallInst *SingleEntryCI = cast<CallInst>(CondInst->getOperand(0));
+  EXPECT_EQ(SingleEntryCI->arg_size(), 2U);
+  EXPECT_EQ(SingleEntryCI->getCalledFunction()->getName(), "__kmpc_single");
+  EXPECT_TRUE(isa<GlobalVariable>(SingleEntryCI->getArgOperand(0)));
+
+  CallInst *SingleEndCI = nullptr;
+  for (auto &FI : *ThenBB) {
+    Instruction *Cur = &FI;
+    if (isa<CallInst>(Cur)) {
+      SingleEndCI = cast<CallInst>(Cur);
+      if (SingleEndCI->getCalledFunction()->getName() == "__kmpc_end_single")
+        break;
+      SingleEndCI = nullptr;
+    }
+  }
+  EXPECT_NE(SingleEndCI, nullptr);
+  EXPECT_EQ(SingleEndCI->arg_size(), 2U);
+  EXPECT_TRUE(isa<GlobalVariable>(SingleEndCI->getArgOperand(0)));
+  EXPECT_EQ(SingleEndCI->getArgOperand(1), SingleEntryCI->getArgOperand(1));
+
+  CallInst *CopyPrivateCI = nullptr;
+  bool FoundBarrier = false;
+  for (auto &FI : *ExitBB) {
+    Instruction *Cur = &FI;
+    if (auto *CI = dyn_cast<CallInst>(Cur)) {
+      if (CI->getCalledFunction()->getName() == "__kmpc_barrier")
+        FoundBarrier = true;
+      else if (CI->getCalledFunction()->getName() == "__kmpc_copyprivate")
+        CopyPrivateCI = CI;
+    }
+  }
+  EXPECT_FALSE(FoundBarrier);
+  EXPECT_NE(CopyPrivateCI, nullptr);
+  EXPECT_EQ(CopyPrivateCI->arg_size(), 6U);
+  EXPECT_TRUE(isa<AllocaInst>(CopyPrivateCI->getArgOperand(3)));
+  EXPECT_EQ(CopyPrivateCI->getArgOperand(3), CPVar);
+  EXPECT_TRUE(isa<Function>(CopyPrivateCI->getArgOperand(4)));
+  EXPECT_EQ(CopyPrivateCI->getArgOperand(4), CopyFunc);
+  EXPECT_TRUE(isa<LoadInst>(CopyPrivateCI->getArgOperand(5)));
+  LoadInst *DidItLI = cast<LoadInst>(CopyPrivateCI->getArgOperand(5));
+  EXPECT_EQ(DidItLI->getOperand(0), DidIt);
+}
+
 TEST_F(OpenMPIRBuilderTest, OMPAtomicReadFlt) {
   OpenMPIRBuilder OMPBuilder(*M);
   OMPBuilder.initialize();
diff --git a/mlir/lib/Target/LLVMIR/Dialect/OpenMP/OpenMPToLLVMIRTranslation.cpp b/mlir/lib/Target/LLVMIR/Dialect/OpenMP/OpenMPToLLVMIRTranslation.cpp
@@ -656,8 +656,26 @@ convertOmpSingle(omp::SingleOp &singleOp, llvm::IRBuilderBase &builder,
                         moduleTranslation, bodyGenStatus);
   };
   auto finiCB = [&](InsertPointTy codeGenIP) {};
+
+  // Handle copyprivate
+  Operation::operand_range cpVars = singleOp.getCopyprivateVars();
+  std::optional<ArrayAttr> cpFuncs = singleOp.getCopyprivateFuncs();
+  llvm::SmallVector<llvm::Value *> llvmCPVars;
+  llvm::SmallVector<llvm::Function *> llvmCPFuncs;
+  for (size_t i = 0, e = cpVars.size(); i < e; ++i) {
+    llvmCPVars.push_back(moduleTranslation.lookupValue(cpVars[i]));
+    auto llvmFuncOp = SymbolTable::lookupNearestSymbolFrom<LLVM::LLVMFuncOp>(
+        singleOp, cast<SymbolRefAttr>((*cpFuncs)[i]));
+    llvmCPFuncs.push_back(
+        moduleTranslation.lookupFunction(llvmFuncOp.getName()));
+  }
+  llvm::Value *didIt = nullptr;
+  if (!llvmCPVars.empty())
+    didIt = builder.CreateAlloca(llvm::Type::getInt32Ty(builder.getContext()));
+
   builder.restoreIP(moduleTranslation.getOpenMPBuilder()->createSingle(
-      ompLoc, bodyCB, finiCB, singleOp.getNowait(), /*DidIt=*/nullptr));
+      ompLoc, bodyCB, finiCB, singleOp.getNowait(), didIt, llvmCPVars,
+      llvmCPFuncs));
   return bodyGenStatus;
 }
 
diff --git a/mlir/test/Target/LLVMIR/openmp-llvm.mlir b/mlir/test/Target/LLVMIR/openmp-llvm.mlir
@@ -2186,6 +2186,38 @@ llvm.func @single_nowait(%x: i32, %y: i32, %zaddr: !llvm.ptr) {
 
 // -----
 
+llvm.func @copy_i32(!llvm.ptr, !llvm.ptr)
+llvm.func @copy_f32(!llvm.ptr, !llvm.ptr)
+
+// CHECK-LABEL: @single_copyprivate
+// CHECK-SAME: (ptr %[[ip:.*]], ptr %[[fp:.*]])
+llvm.func @single_copyprivate(%ip: !llvm.ptr, %fp: !llvm.ptr) {
+  // CHECK: call i32 @__kmpc_single
+  omp.single copyprivate(%ip -> @copy_i32 : !llvm.ptr, %fp -> @copy_f32 : !llvm.ptr) {
+    // CHECK: %[[i:.*]] = load i32, ptr %[[ip]]
+    %i = llvm.load %ip : !llvm.ptr -> i32
+    // CHECK: %[[i2:.*]] = add i32 %[[i]], %[[i]]
+    %i2 = llvm.add %i, %i : i32
+    // CHECK: store i32 %[[i2]], ptr %[[ip]]
+    llvm.store %i2, %ip : i32, !llvm.ptr
+    // CHECK: %[[f:.*]] = load float, ptr %[[fp]]
+    %f = llvm.load %fp : !llvm.ptr -> f32
+    // CHECK: %[[f2:.*]] = fadd float %[[f]], %[[f]]
+    %f2 = llvm.fadd %f, %f : f32
+    // CHECK: store float %[[f2]], ptr %[[fp]]
+    llvm.store %f2, %fp : f32, !llvm.ptr
+    // CHECK: call void @__kmpc_end_single
+    // CHECK: call void @__kmpc_copyprivate({{.*}}, ptr %[[ip]], ptr @copy_i32, {{.*}})
+    // CHECK: call void @__kmpc_copyprivate({{.*}}, ptr %[[fp]], ptr @copy_f32, {{.*}})
+    // CHECK-NOT: call void @__kmpc_barrier
+    omp.terminator
+  }
+  // CHECK: ret void
+  llvm.return
+}
+
+// -----
+
 // CHECK: @_QFsubEx = internal global i32 undef
 // CHECK: @_QFsubEx.cache = common global ptr null
 
