[mlir][OpenMP] Add __atomic_store to AtomicInfo (#121055)

This PR adds functionality for `__atomic_store` libcall in AtomicInfo.
This allows for supporting complex types in `atomic write`.

Fixes #113479
Fixes #115652

Author: NimishMishra

llvm/include/llvm/Frontend/Atomic/Atomic.h

@@ -97,6 +97,8 @@ class AtomicInfo {
                             bool IsVolatile, bool IsWeak);
 
   std::pair<LoadInst *, AllocaInst *> EmitAtomicLoadLibcall(AtomicOrdering AO);
+
+  void EmitAtomicStoreLibcall(AtomicOrdering AO, Value *Source);
 };
 } // end namespace llvm
 

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

@@ -3285,11 +3285,12 @@ class OpenMPIRBuilder {
   /// \param Expr		The value to store.
   /// \param AO			Atomic ordering of the generated atomic
   ///               instructions.
+  /// \param AllocaIP           Insert point for allocas
   ///
   /// \return Insertion point after generated atomic Write IR.
   InsertPointTy createAtomicWrite(const LocationDescription &Loc,
                                   AtomicOpValue &X, Value *Expr,
-                                  AtomicOrdering AO);
+                                  AtomicOrdering AO, InsertPointTy AllocaIP);
 
   /// Emit atomic update for constructs: X = X BinOp Expr ,or X = Expr BinOp X
   /// For complex Operations: X = UpdateOp(X) => CmpExch X, old_X, UpdateOp(X)

llvm/lib/Frontend/Atomic/Atomic.cpp

@@ -145,6 +145,42 @@ AtomicInfo::EmitAtomicLoadLibcall(AtomicOrdering AO) {
       AllocaResult);
 }
 
+void AtomicInfo::EmitAtomicStoreLibcall(AtomicOrdering AO, Value *Source) {
+  LLVMContext &Ctx = getLLVMContext();
+  SmallVector<Value *, 6> Args;
+  AttributeList Attr;
+  Module *M = Builder->GetInsertBlock()->getModule();
+  const DataLayout &DL = M->getDataLayout();
+  Args.push_back(
+      ConstantInt::get(DL.getIntPtrType(Ctx), this->getAtomicSizeInBits() / 8));
+
+  Value *PtrVal = getAtomicPointer();
+  PtrVal = Builder->CreateAddrSpaceCast(PtrVal, PointerType::getUnqual(Ctx));
+  Args.push_back(PtrVal);
+
+  auto CurrentIP = Builder->saveIP();
+  Builder->restoreIP(AllocaIP);
+  Value *SourceAlloca = Builder->CreateAlloca(Source->getType());
+  Builder->restoreIP(CurrentIP);
+  Builder->CreateStore(Source, SourceAlloca);
+  SourceAlloca = Builder->CreatePointerBitCastOrAddrSpaceCast(
+      SourceAlloca, Builder->getPtrTy());
+  Args.push_back(SourceAlloca);
+
+  Constant *OrderingVal =
+      ConstantInt::get(Type::getInt32Ty(Ctx), (int)toCABI(AO));
+  Args.push_back(OrderingVal);
+
+  SmallVector<Type *, 6> ArgTys;
+  for (Value *Arg : Args)
+    ArgTys.push_back(Arg->getType());
+  FunctionType *FnType = FunctionType::get(Type::getVoidTy(Ctx), ArgTys, false);
+  FunctionCallee LibcallFn =
+      M->getOrInsertFunction("__atomic_store", FnType, Attr);
+  CallInst *Call = Builder->CreateCall(LibcallFn, Args);
+  Call->setAttributes(Attr);
+}
+
 std::pair<Value *, Value *> AtomicInfo::EmitAtomicCompareExchange(
     Value *ExpectedVal, Value *DesiredVal, AtomicOrdering Success,
     AtomicOrdering Failure, bool IsVolatile, bool IsWeak) {

llvm/lib/Frontend/OpenMP/OMPIRBuilder.cpp

@@ -8684,20 +8684,30 @@ OpenMPIRBuilder::createAtomicRead(const LocationDescription &Loc,
 OpenMPIRBuilder::InsertPointTy
 OpenMPIRBuilder::createAtomicWrite(const LocationDescription &Loc,
                                    AtomicOpValue &X, Value *Expr,
-                                   AtomicOrdering AO) {
+                                   AtomicOrdering AO, InsertPointTy AllocaIP) {
   if (!updateToLocation(Loc))
     return Loc.IP;
 
   assert(X.Var->getType()->isPointerTy() &&
          "OMP Atomic expects a pointer to target memory");
   Type *XElemTy = X.ElemTy;
   assert((XElemTy->isFloatingPointTy() || XElemTy->isIntegerTy() ||
-          XElemTy->isPointerTy()) &&
+          XElemTy->isPointerTy() || XElemTy->isStructTy()) &&
          "OMP atomic write expected a scalar type");
 
   if (XElemTy->isIntegerTy()) {
     StoreInst *XSt = Builder.CreateStore(Expr, X.Var, X.IsVolatile);
     XSt->setAtomic(AO);
+  } else if (XElemTy->isStructTy()) {
+    LoadInst *OldVal = Builder.CreateLoad(XElemTy, X.Var, "omp.atomic.read");
+    const DataLayout &LoadDL = OldVal->getModule()->getDataLayout();
+    unsigned LoadSize =
+        LoadDL.getTypeStoreSize(OldVal->getPointerOperand()->getType());
+    OpenMPIRBuilder::AtomicInfo atomicInfo(
+        &Builder, XElemTy, LoadSize * 8, LoadSize * 8, OldVal->getAlign(),
+        OldVal->getAlign(), true /* UseLibcall */, AllocaIP, X.Var);
+    atomicInfo.EmitAtomicStoreLibcall(AO, Expr);
+    OldVal->eraseFromParent();
   } else {
     // We need to bitcast and perform atomic op as integers
     IntegerType *IntCastTy =

llvm/unittests/Frontend/OpenMPIRBuilderTest.cpp

@@ -3875,6 +3875,9 @@ TEST_F(OpenMPIRBuilderTest, OMPAtomicWriteFlt) {
   IRBuilder<> Builder(BB);
 
   OpenMPIRBuilder::LocationDescription Loc({Builder.saveIP(), DL});
+  BasicBlock *EntryBB = BB;
+  OpenMPIRBuilder::InsertPointTy AllocaIP(EntryBB,
+                                          EntryBB->getFirstInsertionPt());
 
   LLVMContext &Ctx = M->getContext();
   Type *Float32 = Type::getFloatTy(Ctx);
@@ -3884,7 +3887,8 @@ TEST_F(OpenMPIRBuilderTest, OMPAtomicWriteFlt) {
   AtomicOrdering AO = AtomicOrdering::Monotonic;
   Constant *ValToWrite = ConstantFP::get(Float32, 1.0);
 
-  Builder.restoreIP(OMPBuilder.createAtomicWrite(Loc, X, ValToWrite, AO));
+  Builder.restoreIP(
+      OMPBuilder.createAtomicWrite(Loc, X, ValToWrite, AO, AllocaIP));
 
   IntegerType *IntCastTy =
       IntegerType::get(M->getContext(), Float32->getScalarSizeInBits());
@@ -3918,8 +3922,11 @@ TEST_F(OpenMPIRBuilderTest, OMPAtomicWriteInt) {
   ConstantInt *ValToWrite = ConstantInt::get(Type::getInt32Ty(Ctx), 1U);
 
   BasicBlock *EntryBB = BB;
+  OpenMPIRBuilder::InsertPointTy AllocaIP(EntryBB,
+                                          EntryBB->getFirstInsertionPt());
 
-  Builder.restoreIP(OMPBuilder.createAtomicWrite(Loc, X, ValToWrite, AO));
+  Builder.restoreIP(
+      OMPBuilder.createAtomicWrite(Loc, X, ValToWrite, AO, AllocaIP));
 
   StoreInst *StoreofAtomic = nullptr;
 

mlir/lib/Target/LLVMIR/Dialect/OpenMP/OpenMPToLLVMIRTranslation.cpp

@@ -2808,6 +2808,8 @@ convertOmpAtomicWrite(Operation &opInst, llvm::IRBuilderBase &builder,
     return failure();
 
   llvm::OpenMPIRBuilder *ompBuilder = moduleTranslation.getOpenMPBuilder();
+  llvm::OpenMPIRBuilder::InsertPointTy allocaIP =
+      findAllocaInsertPoint(builder, moduleTranslation);
 
   llvm::OpenMPIRBuilder::LocationDescription ompLoc(builder);
   llvm::AtomicOrdering ao = convertAtomicOrdering(writeOp.getMemoryOrder());
@@ -2816,7 +2818,8 @@ convertOmpAtomicWrite(Operation &opInst, llvm::IRBuilderBase &builder,
   llvm::Type *ty = moduleTranslation.convertType(writeOp.getExpr().getType());
   llvm::OpenMPIRBuilder::AtomicOpValue x = {dest, ty, /*isSigned=*/false,
                                             /*isVolatile=*/false};
-  builder.restoreIP(ompBuilder->createAtomicWrite(ompLoc, x, expr, ao));
+  builder.restoreIP(
+      ompBuilder->createAtomicWrite(ompLoc, x, expr, ao, allocaIP));
   return success();
 }
 

mlir/test/Target/LLVMIR/openmp-llvm.mlir

@@ -1481,6 +1481,49 @@ llvm.func @omp_atomic_update(%x:!llvm.ptr, %expr: i32, %xbool: !llvm.ptr, %exprb
 
 // -----
 
+// CHECK-LABEL: @omp_atomic_write
+llvm.func @omp_atomic_write() {
+// CHECK: %[[ALLOCA0:.*]] = alloca { float, float }, align 8
+// CHECK: %[[ALLOCA1:.*]] = alloca { float, float }, align 8
+// CHECK: %[[X:.*]] = alloca float, i64 1, align 4
+// CHECK: %[[R1:.*]] = alloca float, i64 1, align 4
+// CHECK: %[[ALLOCA:.*]] = alloca { float, float }, i64 1, align 8
+// CHECK: %[[LOAD:.*]] = load float, ptr %[[R1]], align 4
+// CHECK: %[[IDX1:.*]] = insertvalue { float, float } undef, float %[[LOAD]], 0
+// CHECK: %[[IDX2:.*]] = insertvalue { float, float } %[[IDX1]], float 0.000000e+00, 1
+// CHECK: br label %entry
+
+// CHECK: entry:
+// CHECK: store { float, float } %[[IDX2]], ptr %[[ALLOCA1]], align 4
+// CHECK: call void @__atomic_store(i64 8, ptr %[[ALLOCA]], ptr %[[ALLOCA1]], i32 0)
+// CHECK: store { float, float } { float 1.000000e+00, float 1.000000e+00 }, ptr %[[ALLOCA0]], align 4
+// CHECK: call void @__atomic_store(i64 8, ptr %[[ALLOCA]], ptr %[[ALLOCA0]], i32 0)
+
+    %0 = llvm.mlir.constant(1 : i64) : i64
+    %1 = llvm.alloca %0 x f32 {bindc_name = "x"} : (i64) -> !llvm.ptr
+    %2 = llvm.mlir.constant(1 : i64) : i64
+    %3 = llvm.alloca %2 x f32 {bindc_name = "r1"} : (i64) -> !llvm.ptr
+    %4 = llvm.mlir.constant(1 : i64) : i64
+    %5 = llvm.alloca %4 x !llvm.struct<(f32, f32)> {bindc_name = "c1"} : (i64) -> !llvm.ptr
+    %6 = llvm.mlir.constant(1.000000e+00 : f32) : f32
+    %7 = llvm.mlir.constant(0.000000e+00 : f32) : f32
+    %8 = llvm.mlir.constant(1 : i64) : i64
+    %9 = llvm.mlir.constant(1 : i64) : i64
+    %10 = llvm.mlir.constant(1 : i64) : i64
+    %11 = llvm.load %3 : !llvm.ptr -> f32
+    %12 = llvm.mlir.undef : !llvm.struct<(f32, f32)>
+    %13 = llvm.insertvalue %11, %12[0] : !llvm.struct<(f32, f32)>
+    %14 = llvm.insertvalue %7, %13[1] : !llvm.struct<(f32, f32)>
+    omp.atomic.write %5 = %14 : !llvm.ptr, !llvm.struct<(f32, f32)>
+    %15 = llvm.mlir.undef : !llvm.struct<(f32, f32)>
+    %16 = llvm.insertvalue %6, %15[0] : !llvm.struct<(f32, f32)>
+    %17 = llvm.insertvalue %6, %16[1] : !llvm.struct<(f32, f32)>
+    omp.atomic.write %5 = %17 : !llvm.ptr, !llvm.struct<(f32, f32)>
+    llvm.return
+}
+
+// -----
+
 //CHECK: %[[ATOMIC_TEMP_LOAD:.*]] = alloca { float, float }, align 8
 //CHECK: %[[X_NEW_VAL:.*]] = alloca { float, float }, align 8
 //CHECK: {{.*}} = alloca { float, float }, i64 1, align 8