[flang] Lower hlfir.eoshift to the runtime call. (#153107)

Straightforward lowering of hlfir.eoshift to the runtime call
in LowerHLFIRIntrinsics pass.

Author: vzakhari

flang/lib/Optimizer/HLFIR/Transforms/LowerHLFIRIntrinsics.cpp

@@ -469,33 +469,49 @@ struct MatmulTransposeOpConversion
   }
 };
 
-class CShiftOpConversion : public HlfirIntrinsicConversion<hlfir::CShiftOp> {
-  using HlfirIntrinsicConversion<hlfir::CShiftOp>::HlfirIntrinsicConversion;
+// A converter for hlfir.cshift and hlfir.eoshift.
+template <typename T>
+class ArrayShiftOpConversion : public HlfirIntrinsicConversion<T> {
+  using HlfirIntrinsicConversion<T>::HlfirIntrinsicConversion;
+  using HlfirIntrinsicConversion<T>::lowerArguments;
+  using HlfirIntrinsicConversion<T>::processReturnValue;
+  using typename HlfirIntrinsicConversion<T>::IntrinsicArgument;
 
   llvm::LogicalResult
-  matchAndRewrite(hlfir::CShiftOp cshift,
-                  mlir::PatternRewriter &rewriter) const override {
-    fir::FirOpBuilder builder{rewriter, cshift.getOperation()};
-    const mlir::Location &loc = cshift->getLoc();
+  matchAndRewrite(T op, mlir::PatternRewriter &rewriter) const override {
+    fir::FirOpBuilder builder{rewriter, op.getOperation()};
+    const mlir::Location &loc = op->getLoc();
 
-    llvm::SmallVector<IntrinsicArgument, 3> inArgs;
-    mlir::Value array = cshift.getArray();
+    llvm::SmallVector<IntrinsicArgument, 4> inArgs;
+    llvm::StringRef intrinsicName{[]() {
+      if constexpr (std::is_same_v<T, hlfir::EOShiftOp>)
+        return "eoshift";
+      else if constexpr (std::is_same_v<T, hlfir::CShiftOp>)
+        return "cshift";
+      else
+        llvm_unreachable("unsupported array shift");
+    }()};
+
+    mlir::Value array = op.getArray();
     inArgs.push_back({array, array.getType()});
-    mlir::Value shift = cshift.getShift();
+    mlir::Value shift = op.getShift();
     inArgs.push_back({shift, shift.getType()});
-    inArgs.push_back({cshift.getDim(), builder.getI32Type()});
+    if constexpr (std::is_same_v<T, hlfir::EOShiftOp>) {
+      mlir::Value boundary = op.getBoundary();
+      inArgs.push_back({boundary, boundary ? boundary.getType() : nullptr});
+    }
+    inArgs.push_back({op.getDim(), builder.getI32Type()});
 
-    auto *argLowering = fir::getIntrinsicArgumentLowering("cshift");
+    auto *argLowering = fir::getIntrinsicArgumentLowering(intrinsicName);
     llvm::SmallVector<fir::ExtendedValue, 3> args =
-        lowerArguments(cshift, inArgs, rewriter, argLowering);
+        lowerArguments(op, inArgs, rewriter, argLowering);
 
-    mlir::Type scalarResultType =
-        hlfir::getFortranElementType(cshift.getType());
+    mlir::Type scalarResultType = hlfir::getFortranElementType(op.getType());
 
-    auto [resultExv, mustBeFreed] =
-        fir::genIntrinsicCall(builder, loc, "cshift", scalarResultType, args);
+    auto [resultExv, mustBeFreed] = fir::genIntrinsicCall(
+        builder, loc, intrinsicName, scalarResultType, args);
 
-    processReturnValue(cshift, resultExv, mustBeFreed, builder, rewriter);
+    processReturnValue(op, resultExv, mustBeFreed, builder, rewriter);
     return mlir::success();
   }
 };
@@ -547,7 +563,8 @@ class LowerHLFIRIntrinsics
         AnyOpConversion, SumOpConversion, ProductOpConversion,
         TransposeOpConversion, CountOpConversion, DotProductOpConversion,
         MaxvalOpConversion, MinvalOpConversion, MinlocOpConversion,
-        MaxlocOpConversion, CShiftOpConversion, ReshapeOpConversion>(context);
+        MaxlocOpConversion, ArrayShiftOpConversion<hlfir::CShiftOp>,
+        ArrayShiftOpConversion<hlfir::EOShiftOp>, ReshapeOpConversion>(context);
 
     // While conceptually this pass is performing dialect conversion, we use
     // pattern rewrites here instead of dialect conversion because this pass