[FLANG][NFCI]De-duplicate code in SimplifyIntrinsics

[Leporacanthicus]

Summary

This removes a bunch of duplicated code, by adding an intermediate
function simplifyReduction that takes a std::function argument
for the actual replacement of the code.

No functional change intended.

[Leporacanthicus]

Updated comment for helper function

[vzakhari]

flang/lib/Optimizer/Transforms/SimplifyIntrinsics.cpp

53

I was recently told that we do not usually use std::function. The advice was to replace it with function_ref: https://reviews.llvm.org/D129810#inline-1277689

75

typo: hte

76

typo? simplifyd -> simplified or simplify?

[Leporacanthicus]

Updates per review comments:

• Fix typos
• Use llvm::function_ref instead of std::function

[vzakhari]

Thanks for function_ref replacements!

flang/lib/Optimizer/Transforms/SimplifyIntrinsics.cpp

76

[Leporacanthicus]

flang/lib/Optimizer/Transforms/SimplifyIntrinsics.cpp

53

Ok, there's only 5 in this section of code, I will fix those.

There's 115 std::function and 10 llvm::function_ref in flang - not making excuses here, but I think a separate cleanup patch may be required.

I will see if I can fix that separately after this has gone in as a "good citizen" patch.

[vzakhari]

flang/lib/Optimizer/Transforms/SimplifyIntrinsics.cpp

53

Sure, the other places can be cleaned up separately.

[Leporacanthicus]

Added const to KindMapping argument.

[Leporacanthicus]

flang/lib/Optimizer/Transforms/SimplifyIntrinsics.cpp

76

I'm sure I fixed this before now. Anyway, thanks for spotting!

[vzakhari]

Thanks for the changes! LGTM

flang/lib/Optimizer/Transforms/SimplifyIntrinsics.cpp

 
 #define DEBUG_TYPE "flang-simplify-intrinsics"
 
 namespace {
 
 class SimplifyIntrinsicsPass
     : public fir::SimplifyIntrinsicsBase<SimplifyIntrinsicsPass> {
   using FunctionTypeGeneratorTy =
-      std::function<mlir::FunctionType(fir::FirOpBuilder &)>;
+      llvm::function_ref<mlir::FunctionType(fir::FirOpBuilder &)>;
   using FunctionBodyGeneratorTy =
-      std::function<void(fir::FirOpBuilder &, mlir::func::FuncOp &)>;
+      llvm::function_ref<void(fir::FirOpBuilder &, mlir::func::FuncOp &)>;
+  using GenReductionBodyTy = llvm::function_ref<void(
+      fir::FirOpBuilder &builder, mlir::func::FuncOp &funcOp)>;
 
 public:
   /// Generate a new function implementing a simplified version
   /// of a Fortran runtime function defined by \p basename name.
   /// \p typeGenerator is a callback that generates the new function's type.
   /// \p bodyGenerator is a callback that generates the new function's body.
   /// The new function is created in the \p builder's Module.
   mlir::func::FuncOp getOrCreateFunction(fir::FirOpBuilder &builder,
                                          const mlir::StringRef &basename,
                                          FunctionTypeGeneratorTy typeGenerator,
                                          FunctionBodyGeneratorTy bodyGenerator);
   void runOnOperation() override;
   void getDependentDialects(mlir::DialectRegistry &registry) const override;
+
+private:
+  /// Helper function to replace a reduction type of call with its
+  /// simplified form. The actual function is generated using a callback
+  /// function.
+  /// \p call is the call to be replaced
+  /// \p kindMap is used to create FIROpBuilder
+  /// \p genBodyFunc is the callback that builds the replacement function
+  void simplifyReduction(fir::CallOp call, const fir::KindMapping &kindMap,
+                         GenReductionBodyTy genBodyFunc);
 };
 
 } // namespace
 
 /// Generate function type for the simplified version of FortranASum and
 /// similar functions with a fir.box<none> type returning \p elementType.
 static mlir::FunctionType genNoneBoxType(fir::FirOpBuilder &builder,
                                          const mlir::Type &elementType) {
   mlir::Type boxType = fir::BoxType::get(builder.getNoneType());
   return mlir::FunctionType::get(builder.getContext(), {boxType},
                                  {elementType});
 }
 
-using BodyOpGeneratorTy =
-    std::function<mlir::Value(fir::FirOpBuilder &, mlir::Location,
-                              const mlir::Type &, mlir::Value, mlir::Value)>;
-using InitValGeneratorTy = std::function<mlir::Value(
+using BodyOpGeneratorTy = llvm::function_ref<mlir::Value(
+    fir::FirOpBuilder &, mlir::Location, const mlir::Type &, mlir::Value,
+    mlir::Value)>;
+using InitValGeneratorTy = llvm::function_ref<mlir::Value(
     fir::FirOpBuilder &, mlir::Location, const mlir::Type &)>;
 
 /// Generate the reduction loop into \p funcOp.
 ///
 /// \p initVal is a function, called to get the initial value for
 ///    the reduction value
 /// \p genBody is called to fill in the actual reduciton operation
 ///    for example add for SUM, MAX for MAXVAL, etc.
do {
     // box type to another box type.
     auto boxType = val.getType().cast<fir::BoxType>();
     auto elementType = fir::unwrapSeqOrBoxedSeqType(boxType);
     if (!elementType.isa<mlir::NoneType>())
       return elementType;
   } while (true);
 }
 
-void SimplifyIntrinsicsPass::runOnOperation() {
-  LLVM_DEBUG(llvm::dbgs() << "=== Begin " DEBUG_TYPE " ===\n");
-  mlir::ModuleOp module = getOperation();
-  fir::KindMapping kindMap = fir::getKindMapping(module);
-  module.walk([&](mlir::Operation *op) {
-    if (auto call = mlir::dyn_cast<fir::CallOp>(op)) {
-      if (mlir::SymbolRefAttr callee = call.getCalleeAttr()) {
-        mlir::StringRef funcName = callee.getLeafReference().getValue();
-        // Replace call to runtime function for SUM when it has single
-        // argument (no dim or mask argument) for 1D arrays with either
-        // Integer4 or Real8 types. Other forms are ignored.
-        // The new function is added to the module.
-        //
-        // Prototype for runtime call (from sum.cpp):
-        // RTNAME(Sum<T>)(const Descriptor &x, const char *source, int line,
-        //                int dim, const Descriptor *mask)
-        //
-        if (funcName.startswith("_FortranASum")) {
-          mlir::Operation::operand_range args = call.getArgs();
-          // args[1] and args[2] are source filename and line number, ignored.
-          const mlir::Value &dim = args[3];
-          const mlir::Value &mask = args[4];
-          // dim is zero when it is absent, which is an implementation
-          // detail in the runtime library.
-          bool dimAndMaskAbsent = isZero(dim) && isOperandAbsent(mask);
-          unsigned rank = getDimCount(args[0]);
-          if (dimAndMaskAbsent && rank == 1) {
-            mlir::Location loc = call.getLoc();
-            mlir::Type type;
-            fir::FirOpBuilder builder(op, kindMap);
-            if (funcName.endswith("Integer4")) {
-              type = mlir::IntegerType::get(builder.getContext(), 32);
-            } else if (funcName.endswith("Real8")) {
-              type = mlir::FloatType::getF64(builder.getContext());
-            } else {
-              return;
-            }
-            auto typeGenerator = [&type](fir::FirOpBuilder &builder) {
-              return genNoneBoxType(builder, type);
-            };
-            mlir::func::FuncOp newFunc = getOrCreateFunction(
-                builder, funcName, typeGenerator, genFortranASumBody);
-            auto newCall = builder.create<fir::CallOp>(
-                loc, newFunc, mlir::ValueRange{args[0]});
-            call->replaceAllUsesWith(newCall.getResults());
-            call->dropAllReferences();
-            call->erase();
-          }
+void SimplifyIntrinsicsPass::simplifyReduction(fir::CallOp call,
+                                               const fir::KindMapping &kindMap,
+                                               GenReductionBodyTy genBodyFunc) {
+  mlir::SymbolRefAttr callee = call.getCalleeAttr();
+    fir::FirOpBuilder builder(call, kindMap);
+    mlir::func::FuncOp newFunc =
+        getOrCreateFunction(builder, funcName, typeGenerator, genBodyFunc);
+    auto newCall =
+        builder.create<fir::CallOp>(loc, newFunc, mlir::ValueRange{args[0]});
+}
 
+void SimplifyIntrinsicsPass::runOnOperation() {
+  LLVM_DEBUG(llvm::dbgs() << "=== Begin " DEBUG_TYPE " ===\n");
+  mlir::ModuleOp module = getOperation();
+  fir::KindMapping kindMap = fir::getKindMapping(module);
+  module.walk([&](mlir::Operation *op) {
+    if (auto call = mlir::dyn_cast<fir::CallOp>(op)) {
+      if (mlir::SymbolRefAttr callee = call.getCalleeAttr()) {
+        mlir::StringRef funcName = callee.getLeafReference().getValue();
+        // Replace call to runtime function for SUM when it has single
+        // argument (no dim or mask argument) for 1D arrays with either
+        // Integer4 or Real8 types. Other forms are ignored.
+        // The new function is added to the module.
+        //
+        // Prototype for runtime call (from sum.cpp):
+        // RTNAME(Sum<T>)(const Descriptor &x, const char *source, int line,
+        //                int dim, const Descriptor *mask)
+        //
+        if (funcName.startswith("_FortranASum")) {
+          simplifyReduction(call, kindMap, genFortranASumBody);
           return;
         }
         if (funcName.startswith("_FortranADotProduct")) {
           LLVM_DEBUG(llvm::dbgs() << "Handling " << funcName << "\n");
           LLVM_DEBUG(llvm::dbgs() << "Call operation:\n"; op->dump();
                      llvm::dbgs() << "\n");
           mlir::Operation::operand_range args = call.getArgs();
           const mlir::Value &v1 = args[0];
if (auto call = mlir::dyn_cast<fir::CallOp>(op)) {
           call->dropAllReferences();
           call->erase();
 
           LLVM_DEBUG(llvm::dbgs() << "Replaced with:\n"; newCall.dump();
                      llvm::dbgs() << "\n");
           return;
         }
         if (funcName.startswith("_FortranAMaxval")) {
-          mlir::Operation::operand_range args = call.getArgs();
-          const mlir::Value &dim = args[3];
-          const mlir::Value &mask = args[4];
-          // dim is zero when it is absent, which is an implementation
-          // detail in the runtime library.
-          bool dimAndMaskAbsent = isZero(dim) && isOperandAbsent(mask);
-          unsigned rank = getDimCount(args[0]);
-          if (dimAndMaskAbsent && rank == 1) {
-            mlir::Location loc = call.getLoc();
-            mlir::Type type;
-            fir::FirOpBuilder builder(op, kindMap);
-            if (funcName.endswith("Integer4")) {
-              type = mlir::IntegerType::get(builder.getContext(), 32);
-            } else if (funcName.endswith("Real8")) {
-              type = mlir::FloatType::getF64(builder.getContext());
-            } else {
-              return;
-            }
-            auto typeGenerator = [&type](fir::FirOpBuilder &builder) {
-              return genNoneBoxType(builder, type);
-            };
-            mlir::func::FuncOp newFunc = getOrCreateFunction(
-                builder, funcName, typeGenerator, genFortranAMaxvalBody);
-            auto newCall = builder.create<fir::CallOp>(
-                loc, newFunc, mlir::ValueRange{args[0]});
-            call->replaceAllUsesWith(newCall.getResults());
-            call->dropAllReferences();
-            call->erase();
-            return;
-          }
-        }
-      }
-    }
+          simplifyReduction(call, kindMap, genFortranAMaxvalBody);
   });
   LLVM_DEBUG(llvm::dbgs() << "=== End " DEBUG_TYPE " ===\n");
 }
 
 void SimplifyIntrinsicsPass::getDependentDialects(
     mlir::DialectRegistry &registry) const {
   // LLVM::LinkageAttr creation requires that LLVM dialect is loaded.
   registry.insert<mlir::LLVM::LLVMDialect>();
 }
 std::unique_ptr<mlir::Pass> fir::createSimplifyIntrinsicsPass() {
   return std::make_unique<SimplifyIntrinsicsPass>();
 }