[CIR] Backport ComplexImagOp on scalar type

clang/include/clang/CIR/Dialect/Builder/CIRBaseBuilder.h

@@ -337,9 +337,10 @@ class CIRBaseBuilderTy : public mlir::OpBuilder {
   }
 
   mlir::Value createComplexImag(mlir::Location loc, mlir::Value operand) {
-    auto operandTy = mlir::cast<cir::ComplexType>(operand.getType());
-    return cir::ComplexImagOp::create(*this, loc, operandTy.getElementType(),
-                                      operand);
+    auto resultType = operand.getType();
+    if (auto complexResultType = mlir::dyn_cast<cir::ComplexType>(resultType))
+      resultType = complexResultType.getElementType();
+    return cir::ComplexImagOp::create(*this, loc, resultType, operand);
   }
 
   mlir::Value createComplexBinOp(mlir::Location loc, mlir::Value lhs,

clang/include/clang/CIR/Dialect/IR/CIROps.td

@@ -1539,18 +1539,20 @@ def CIR_ComplexRealOp : CIR_Op<"complex.real", [Pure]> {
 def CIR_ComplexImagOp : CIR_Op<"complex.imag", [Pure]> {
   let summary = "Extract the imaginary part of a complex value";
   let description = [{
-    `cir.complex.imag` operation takes an operand of `!cir.complex` type and
-    yields the imaginary part of it.
+    `cir.complex.imag` operation takes an operand of `!cir.complex`, `!cir.int`
+    or `!cir.float`. If the operand is `!cir.complex`, the imag part of it will
+    be returned, otherwise a zero value will be returned.
 
     Example:
 
     ```mlir
-    %1 = cir.complex.imag %0 : !cir.complex<!cir.float> -> !cir.float
+    %imag = cir.complex.imag %complex : !cir.complex<!cir.float> -> !cir.float
+    %imag = cir.complex.imag %scalar : !cir.float -> !cir.float
     ```
   }];
 
   let results = (outs CIR_AnyIntOrFloatType:$result);
-  let arguments = (ins CIR_ComplexType:$operand);
+  let arguments = (ins CIR_AnyComplexOrIntOrFloatType:$operand);
 
   let assemblyFormat = [{
     $operand `:` qualified(type($operand)) `->` qualified(type($result))

clang/lib/CIR/CodeGen/CIRGenExprScalar.cpp

@@ -2127,8 +2127,8 @@ mlir::Value ScalarExprEmitter::VisitImag(const UnaryOperator *E) {
   // TODO(cir): handle scalar promotion.
 
   Expr *Op = E->getSubExpr();
+  mlir::Location Loc = CGF.getLoc(E->getExprLoc());
   if (Op->getType()->isAnyComplexType()) {
-    mlir::Location Loc = CGF.getLoc(E->getExprLoc());
 
     // If it's an l-value, load through the appropriate subobject l-value.
     // Note that we have to ask E because Op might be an l-value that
@@ -2142,7 +2142,7 @@ mlir::Value ScalarExprEmitter::VisitImag(const UnaryOperator *E) {
     return Builder.createComplexImag(Loc, CGF.emitComplexExpr(Op));
   }
 
-  return Visit(Op);
+  return Builder.createComplexImag(Loc, Visit(Op));
 }
 
 // Conversion from bool, integral, or floating-point to integral or

clang/lib/CIR/Dialect/IR/CIRDialect.cpp

@@ -969,14 +969,22 @@ OpFoldResult cir::ComplexRealOp::fold(FoldAdaptor adaptor) {
 }
 
 LogicalResult cir::ComplexImagOp::verify() {
-  if (getType() != getOperand().getType().getElementType()) {
+  mlir::Type operandTy = getOperand().getType();
+  if (auto complexOperandTy = mlir::dyn_cast<cir::ComplexType>(operandTy))
+    operandTy = complexOperandTy.getElementType();
+
+  if (getType() != operandTy) {
     emitOpError() << ": result type does not match operand type";
     return failure();
   }
+
   return success();
 }
 
 OpFoldResult cir::ComplexImagOp::fold(FoldAdaptor adaptor) {
+  if (!mlir::isa<cir::ComplexType>(getOperand().getType()))
+    return nullptr;
+
   if (auto complexCreateOp = getOperand().getDefiningOp<cir::ComplexCreateOp>())
     return complexCreateOp.getOperand(1);
 

clang/lib/CIR/Lowering/DirectToLLVM/LowerToLLVM.cpp

@@ -2597,8 +2597,19 @@ mlir::LogicalResult CIRToLLVMComplexImagOpLowering::matchAndRewrite(
     cir::ComplexImagOp op, OpAdaptor adaptor,
     mlir::ConversionPatternRewriter &rewriter) const {
   auto resultLLVMTy = getTypeConverter()->convertType(op.getType());
-  rewriter.replaceOpWithNewOp<mlir::LLVM::ExtractValueOp>(
-      op, resultLLVMTy, adaptor.getOperand(), llvm::ArrayRef<std::int64_t>{1});
+  mlir::Value operand = adaptor.getOperand();
+  mlir::Location loc = op.getLoc();
+
+  if (mlir::isa<cir::ComplexType>(op.getOperand().getType())) {
+    operand = mlir::LLVM::ExtractValueOp::create(
+        rewriter, loc, resultLLVMTy, operand, llvm::ArrayRef<std::int64_t>{1});
+  } else {
+    mlir::TypedAttr zeroAttr = rewriter.getZeroAttr(resultLLVMTy);
+    operand =
+        mlir::LLVM::ConstantOp::create(rewriter, loc, resultLLVMTy, zeroAttr);
+  }
+
+  rewriter.replaceOp(op, operand);
   return mlir::success();
 }
 

clang/test/CIR/CodeGen/complex.cpp

@@ -390,3 +390,23 @@ void real_on_scalar_glvalue() {
 // OGCG: %[[B_ADDR:.*]] = alloca float, align 4
 // OGCG: %[[TMP_A:.*]] = load float, ptr %[[A_ADDR]], align 4
 // OGCG: store float %[[TMP_A]], ptr %[[B_ADDR]], align 4
+
+void imag_on_scalar_glvalue() {
+  float a;
+  float b = __imag__ a;
+}
+
+// CIR: %[[A_ADDR:.*]] = cir.alloca !cir.float, !cir.ptr<!cir.float>, ["a"]
+// CIR: %[[B_ADDR:.*]] = cir.alloca !cir.float, !cir.ptr<!cir.float>, ["b", init]
+// CIR: %[[TMP_A:.*]] = cir.load{{.*}} %[[A_ADDR]] : !cir.ptr<!cir.float>, !cir.float
+// CIR: %[[A_IMAG:.*]] = cir.complex.imag %[[TMP_A]] : !cir.float -> !cir.float
+// CIR: cir.store{{.*}} %[[A_IMAG]], %[[B_ADDR]] : !cir.float, !cir.ptr<!cir.float>
+
+// LLVM: %[[A_ADDR:.*]] = alloca float, i64 1, align 4
+// LLVM: %[[B_ADDR:.*]] = alloca float, i64 1, align 4
+// LLVM: %[[TMP_A:.*]] = load float, ptr %[[A_ADDR]], align 4
+// LLVM: store float 0.000000e+00, ptr %[[B_ADDR]], align 4
+
+// OGCG: %[[A_ADDR:.*]] = alloca float, align 4
+// OGCG: %[[B_ADDR:.*]] = alloca float, align 4
+// OGCG: store float 0.000000e+00, ptr %[[B_ADDR]], align 4