[CIR][NFCI] Represent Complex RValues As Single Value (#144519)

This patch removes one mlir::Value in the RValue class that has been
used to represent complex values in classic CG. In CIR we plan on
representing complex as a single value. It also removes some now
unnecessary member functions related to complex handling.

Author: mmha

clang/lib/CIR/CodeGen/CIRGenCall.cpp

@@ -443,7 +443,7 @@ RValue CIRGenFunction::emitCall(const CIRGenFunctionInfo &funcInfo,
       mlir::Value v;
       if (arg.isAggregate())
         cgm.errorNYI(loc, "emitCall: aggregate call argument");
-      v = arg.getKnownRValue().getScalarVal();
+      v = arg.getKnownRValue().getValue();
 
       // We might have to widen integers, but we should never truncate.
       if (argType != v.getType() && mlir::isa<cir::IntType>(v.getType()))

clang/lib/CIR/CodeGen/CIRGenExpr.cpp

@@ -219,7 +219,7 @@ void CIRGenFunction::emitStoreThroughLValue(RValue src, LValue dst,
       const mlir::Value vector =
           builder.createLoad(loc, dst.getVectorAddress());
       const mlir::Value newVector = builder.create<cir::VecInsertOp>(
-          loc, vector, src.getScalarVal(), dst.getVectorIdx());
+          loc, vector, src.getValue(), dst.getVectorIdx());
       builder.createStore(loc, newVector, dst.getVectorAddress());
       return;
     }
@@ -232,7 +232,7 @@ void CIRGenFunction::emitStoreThroughLValue(RValue src, LValue dst,
   assert(!cir::MissingFeatures::opLoadStoreObjC());
 
   assert(src.isScalar() && "Can't emit an aggregate store with this method");
-  emitStoreOfScalar(src.getScalarVal(), dst, isInit);
+  emitStoreOfScalar(src.getValue(), dst, isInit);
 }
 
 static LValue emitGlobalVarDeclLValue(CIRGenFunction &cgf, const Expr *e,
@@ -949,7 +949,7 @@ LValue CIRGenFunction::emitCallExprLValue(const CallExpr *e) {
          "Can't have a scalar return unless the return type is a "
          "reference type!");
 
-  return makeNaturalAlignPointeeAddrLValue(rv.getScalarVal(), e->getType());
+  return makeNaturalAlignPointeeAddrLValue(rv.getValue(), e->getType());
 }
 
 LValue CIRGenFunction::emitBinaryOperatorLValue(const BinaryOperator *e) {

clang/lib/CIR/CodeGen/CIRGenExprScalar.cpp

@@ -131,11 +131,11 @@ class ScalarExprEmitter : public StmtVisitor<ScalarExprEmitter, mlir::Value> {
   mlir::Value emitLoadOfLValue(const Expr *e) {
     LValue lv = cgf.emitLValue(e);
     // FIXME: add some akin to EmitLValueAlignmentAssumption(E, V);
-    return cgf.emitLoadOfLValue(lv, e->getExprLoc()).getScalarVal();
+    return cgf.emitLoadOfLValue(lv, e->getExprLoc()).getValue();
   }
 
   mlir::Value emitLoadOfLValue(LValue lv, SourceLocation loc) {
-    return cgf.emitLoadOfLValue(lv, loc).getScalarVal();
+    return cgf.emitLoadOfLValue(lv, loc).getValue();
   }
 
   // l-values
@@ -400,10 +400,10 @@ class ScalarExprEmitter : public StmtVisitor<ScalarExprEmitter, mlir::Value> {
       cgf.cgm.errorNYI(e->getSourceRange(), "Atomic inc/dec");
       // TODO(cir): This is not correct, but it will produce reasonable code
       // until atomic operations are implemented.
-      value = cgf.emitLoadOfLValue(lv, e->getExprLoc()).getScalarVal();
+      value = cgf.emitLoadOfLValue(lv, e->getExprLoc()).getValue();
       input = value;
     } else {
-      value = cgf.emitLoadOfLValue(lv, e->getExprLoc()).getScalarVal();
+      value = cgf.emitLoadOfLValue(lv, e->getExprLoc()).getValue();
       input = value;
     }
 
@@ -1805,7 +1805,7 @@ mlir::Value ScalarExprEmitter::VisitCallExpr(const CallExpr *e) {
   if (e->getCallReturnType(cgf.getContext())->isReferenceType())
     return emitLoadOfLValue(e);
 
-  auto v = cgf.emitCallExpr(e).getScalarVal();
+  auto v = cgf.emitCallExpr(e).getValue();
   assert(!cir::MissingFeatures::emitLValueAlignmentAssumption());
   return v;
 }

clang/lib/CIR/CodeGen/CIRGenStmt.cpp

@@ -391,8 +391,7 @@ mlir::LogicalResult CIRGenFunction::emitReturnStmt(const ReturnStmt &s) {
     // If this function returns a reference, take the address of the
     // expression rather than the value.
     RValue result = emitReferenceBindingToExpr(rv);
-    builder.CIRBaseBuilderTy::createStore(loc, result.getScalarVal(),
-                                          *fnRetAlloca);
+    builder.CIRBaseBuilderTy::createStore(loc, result.getValue(), *fnRetAlloca);
   } else {
     mlir::Value value = nullptr;
     switch (CIRGenFunction::getEvaluationKind(rv->getType())) {

clang/lib/CIR/CodeGen/CIRGenValue.h

@@ -33,11 +33,7 @@ class RValue {
   enum Flavor { Scalar, Complex, Aggregate };
 
   union {
-    // Stores first and second value.
-    struct {
-      mlir::Value first;
-      mlir::Value second;
-    } vals;
+    mlir::Value value;
 
     // Stores aggregate address.
     Address aggregateAddr;
@@ -47,7 +43,7 @@ class RValue {
   unsigned flavor : 2;
 
 public:
-  RValue() : vals{nullptr, nullptr}, flavor(Scalar) {}
+  RValue() : value(nullptr), flavor(Scalar) {}
 
   bool isScalar() const { return flavor == Scalar; }
   bool isComplex() const { return flavor == Complex; }
@@ -56,14 +52,9 @@ class RValue {
   bool isVolatileQualified() const { return isVolatile; }
 
   /// Return the value of this scalar value.
-  mlir::Value getScalarVal() const {
+  mlir::Value getValue() const {
     assert(isScalar() && "Not a scalar!");
-    return vals.first;
-  }
-
-  /// Return the real/imag components of this complex value.
-  std::pair<mlir::Value, mlir::Value> getComplexVal() const {
-    return std::make_pair(vals.first, vals.second);
+    return value;
   }
 
   /// Return the value of the address of the aggregate.
@@ -83,22 +74,20 @@ class RValue {
 
   static RValue get(mlir::Value v) {
     RValue er;
-    er.vals.first = v;
+    er.value = v;
     er.flavor = Scalar;
     er.isVolatile = false;
     return er;
   }
 
-  static RValue getComplex(mlir::Value v1, mlir::Value v2) {
+  static RValue getComplex(mlir::Value v) {
     RValue er;
-    er.vals = {v1, v2};
+    er.value = v;
     er.flavor = Complex;
     er.isVolatile = false;
     return er;
   }
-  static RValue getComplex(const std::pair<mlir::Value, mlir::Value> &c) {
-    return getComplex(c.first, c.second);
-  }
+
   // FIXME: Aggregate rvalues need to retain information about whether they are
   // volatile or not.  Remove default to find all places that probably get this
   // wrong.