Add memory effects

Models memory effects on ops that can take volatile references by
adding read and write effects to the default resource.

Author: ashermancinelli

flang/include/flang/Optimizer/Dialect/FIROps.td

@@ -286,7 +286,7 @@ def fir_FreeMemOp : fir_Op<"freemem", [MemoryEffects<[MemFree]>]> {
   let assemblyFormat = "$heapref attr-dict `:` qualified(type($heapref))";
 }
 
-def fir_LoadOp : fir_OneResultOp<"load", [FirAliasTagOpInterface]> {
+def fir_LoadOp : fir_OneResultOp<"load", [FirAliasTagOpInterface, DeclareOpInterfaceMethods<MemoryEffectsOpInterface>]> {
   let summary = "load a value from a memory reference";
   let description = [{
     Load a value from a memory reference into an ssa-value (virtual register).
@@ -302,7 +302,7 @@ def fir_LoadOp : fir_OneResultOp<"load", [FirAliasTagOpInterface]> {
     or null.
   }];
 
-  let arguments = (ins Arg<AnyReferenceLike, "", [MemRead]>:$memref,
+  let arguments = (ins Arg<AnyReferenceLike, "">:$memref,
                   OptionalAttr<LLVM_TBAATagArrayAttr>:$tbaa);
 
   let builders = [OpBuilder<(ins "mlir::Value":$refVal)>,
@@ -315,7 +315,8 @@ def fir_LoadOp : fir_OneResultOp<"load", [FirAliasTagOpInterface]> {
   }];
 }
 
-def fir_StoreOp : fir_Op<"store", [FirAliasTagOpInterface]> {
+def fir_StoreOp : fir_Op<"store", [FirAliasTagOpInterface,
+                                   DeclareOpInterfaceMethods<MemoryEffectsOpInterface>]> {
   let summary = "store an SSA-value to a memory location";
 
   let description = [{
@@ -335,7 +336,7 @@ def fir_StoreOp : fir_Op<"store", [FirAliasTagOpInterface]> {
   }];
 
   let arguments = (ins AnyType:$value,
-                   Arg<AnyReferenceLike, "", [MemWrite]>:$memref,
+                   Arg<AnyReferenceLike, "">:$memref,
                    OptionalAttr<LLVM_TBAATagArrayAttr>:$tbaa);
 
   let builders = [OpBuilder<(ins "mlir::Value":$value, "mlir::Value":$memref)>];
@@ -1373,7 +1374,7 @@ def fir_BoxTypeDescOp : fir_SimpleOneResultOp<"box_tdesc", [NoMemoryEffect]> {
 //   !- Merge the new and old values into the memory for "A"
 //   array_merge_store <updated A> to <A's address>
 
-def fir_ArrayLoadOp : fir_Op<"array_load", [AttrSizedOperandSegments]> {
+def fir_ArrayLoadOp : fir_Op<"array_load", [AttrSizedOperandSegments, DeclareOpInterfaceMethods<MemoryEffectsOpInterface>]> {
 
   let summary = "Load an array as a value.";
 
@@ -1412,7 +1413,7 @@ def fir_ArrayLoadOp : fir_Op<"array_load", [AttrSizedOperandSegments]> {
   }];
 
   let arguments = (ins
-    Arg<AnyRefOrBox, "", [MemRead]>:$memref,
+    Arg<AnyRefOrBox, "">:$memref,
     Optional<AnyShapeOrShiftType>:$shape,
     Optional<fir_SliceType>:$slice,
     Variadic<AnyIntegerType>:$typeparams

flang/lib/Optimizer/Dialect/FIROps.cpp

@@ -37,6 +37,15 @@ namespace {
 #include "flang/Optimizer/Dialect/CanonicalizationPatterns.inc"
 } // namespace
 
+static void addVolatileMemoryEffects(
+    mlir::Type type, llvm::SmallVectorImpl<mlir::SideEffects::EffectInstance<
+                         mlir::MemoryEffects::Effect>> &effects) {
+  if (fir::isa_volatile_ref_type(type)) {
+    effects.emplace_back(mlir::MemoryEffects::Read::get());
+    effects.emplace_back(mlir::MemoryEffects::Write::get());
+  }
+}
+
 static void propagateAttributes(mlir::Operation *fromOp,
                                 mlir::Operation *toOp) {
   if (!fromOp || !toOp)
@@ -853,6 +862,16 @@ std::vector<mlir::Value> fir::ArrayLoadOp::getExtents() {
   return {};
 }
 
+void fir::ArrayLoadOp::getEffects(
+    llvm::SmallVectorImpl<
+        mlir::SideEffects::EffectInstance<mlir::MemoryEffects::Effect>>
+        &effects) {
+  effects.emplace_back(mlir::MemoryEffects::Read::get(),
+                       &getOperation()->getOpOperand(0),
+                       mlir::SideEffects::DefaultResource::get());
+  addVolatileMemoryEffects(getMemref().getType(), effects);
+}
+
 llvm::LogicalResult fir::ArrayLoadOp::verify() {
   auto eleTy = fir::dyn_cast_ptrOrBoxEleTy(getMemref().getType());
   auto arrTy = mlir::dyn_cast<fir::SequenceType>(eleTy);
@@ -2599,6 +2618,16 @@ void fir::LoadOp::print(mlir::OpAsmPrinter &p) {
   p << " : " << getMemref().getType();
 }
 
+void fir::LoadOp::getEffects(
+    llvm::SmallVectorImpl<
+        mlir::SideEffects::EffectInstance<mlir::MemoryEffects::Effect>>
+        &effects) {
+  effects.emplace_back(mlir::MemoryEffects::Read::get(),
+                       &getOperation()->getOpOperand(0),
+                       mlir::SideEffects::DefaultResource::get());
+  addVolatileMemoryEffects(getMemref().getType(), effects);
+}
+
 //===----------------------------------------------------------------------===//
 // DoLoopOp
 //===----------------------------------------------------------------------===//
@@ -3951,6 +3980,16 @@ void fir::StoreOp::build(mlir::OpBuilder &builder, mlir::OperationState &result,
   build(builder, result, value, memref, {});
 }
 
+void fir::StoreOp::getEffects(
+    llvm::SmallVectorImpl<
+        mlir::SideEffects::EffectInstance<mlir::MemoryEffects::Effect>>
+        &effects) {
+  effects.emplace_back(mlir::MemoryEffects::Write::get(),
+                       &getOperation()->getOpOperand(1),
+                       mlir::SideEffects::DefaultResource::get());
+  addVolatileMemoryEffects(getMemref().getType(), effects);
+}
+
 //===----------------------------------------------------------------------===//
 // CopyOp
 //===----------------------------------------------------------------------===//

flang/lib/Optimizer/HLFIR/IR/HLFIROps.cpp

@@ -61,6 +61,12 @@ getIntrinsicEffects(mlir::Operation *self,
   // }
   for (mlir::OpOperand &operand : self->getOpOperands()) {
     mlir::Type opTy = operand.get().getType();
+    if (fir::isa_volatile_ref_type(opTy)) {
+      effects.emplace_back(mlir::MemoryEffects::Read::get(), &operand,
+                           mlir::SideEffects::DefaultResource::get());
+      effects.emplace_back(mlir::MemoryEffects::Write::get(), &operand,
+                           mlir::SideEffects::DefaultResource::get());
+    }
     if (fir::isa_ref_type(opTy) || fir::isa_box_type(opTy))
       effects.emplace_back(mlir::MemoryEffects::Read::get(), &operand,
                            mlir::SideEffects::DefaultResource::get());
@@ -164,6 +170,12 @@ void hlfir::AssignOp::getEffects(
     }
   }
 
+  if (fir::isa_volatile_ref_type(lhsType) ||
+      fir::isa_volatile_ref_type(rhsType)) {
+    effects.emplace_back(mlir::MemoryEffects::Read::get());
+    effects.emplace_back(mlir::MemoryEffects::Write::get());
+  }
+
   if (getRealloc()) {
     // Reallocation of the data cannot be precisely described by this API.
     effects.emplace_back(mlir::MemoryEffects::Free::get(),