[CIR] Upstream __imag__ for ComplexType

[AmrDeveloper]

This change adds support for __imag__ for ComplexType

#141365

[llvmbot]

@llvm/pr-subscribers-clangir

@llvm/pr-subscribers-clang

Author: Amr Hesham (AmrDeveloper)

Changes

This change adds support for __imag__ for ComplexType

#141365

---

Full diff: https://github.com/llvm/llvm-project/pull/144262.diff

2 Files Affected:

• (modified) clang/lib/CIR/CodeGen/CIRGenExprScalar.cpp (+20)
• (modified) clang/test/CIR/CodeGen/complex.cpp (+23)

diff --git a/clang/lib/CIR/CodeGen/CIRGenExprScalar.cpp b/clang/lib/CIR/CodeGen/CIRGenExprScalar.cpp
index 615a0e7bef556..a1896c5e7f7e5 100644
--- a/clang/lib/CIR/CodeGen/CIRGenExprScalar.cpp
+++ b/clang/lib/CIR/CodeGen/CIRGenExprScalar.cpp
@@ -604,6 +604,7 @@ class ScalarExprEmitter : public StmtVisitor<ScalarExprEmitter, mlir::Value> {
   mlir::Value VisitUnaryLNot(const UnaryOperator *e);
 
   mlir::Value VisitUnaryReal(const UnaryOperator *e);
+  mlir::Value VisitUnaryImag(const UnaryOperator *e);
 
   mlir::Value VisitCXXThisExpr(CXXThisExpr *te) { return cgf.loadCXXThis(); }
 
@@ -1912,6 +1913,25 @@ mlir::Value ScalarExprEmitter::VisitUnaryReal(const UnaryOperator *e) {
   return Visit(op);
 }
 
+mlir::Value ScalarExprEmitter::VisitUnaryImag(const UnaryOperator *e) {
+  // TODO(cir): handle scalar promotion.
+  Expr *op = e->getSubExpr();
+  if (op->getType()->isAnyComplexType()) {
+    // 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
+    // this won't work for, e.g. an Obj-C property.
+    if (e->isGLValue())
+      return cgf.emitLoadOfLValue(cgf.emitLValue(e), e->getExprLoc())
+          .getScalarVal();
+
+    // Otherwise, calculate and project.
+    cgf.cgm.errorNYI(e->getSourceRange(),
+                     "VisitUnaryImag calculate and project");
+  }
+
+  return Visit(op);
+}
+
 /// Return the size or alignment of the type of argument of the sizeof
 /// expression as an integer.
 mlir::Value ScalarExprEmitter::VisitUnaryExprOrTypeTraitExpr(
diff --git a/clang/test/CIR/CodeGen/complex.cpp b/clang/test/CIR/CodeGen/complex.cpp
index 3d1e395d7613c..6c29dc3e1b7fe 100644
--- a/clang/test/CIR/CodeGen/complex.cpp
+++ b/clang/test/CIR/CodeGen/complex.cpp
@@ -226,3 +226,26 @@ void foo12() {
 // OGCG: %[[REAL_PTR:.*]] = getelementptr inbounds nuw { double, double }, ptr %[[COMPLEX]], i32 0, i32 0
 // OGCG: %[[REAL:.*]] = load double, ptr %[[REAL_PTR]], align 8
 // OGCG: store double %[[REAL]], ptr %[[INIT]], align 8
+
+void foo13() {
+  double _Complex c;
+  double imag = __imag__ c;
+}
+
+// CIR: %[[COMPLEX:.*]] = cir.alloca !cir.complex<!cir.double>, !cir.ptr<!cir.complex<!cir.double>>, ["c"]
+// CIR: %[[INIT:.*]] = cir.alloca !cir.double, !cir.ptr<!cir.double>, ["imag", init]
+// CIR: %[[IMAG_PTR:.*]] = cir.complex.imag_ptr %[[COMPLEX]] : !cir.ptr<!cir.complex<!cir.double>> -> !cir.ptr<!cir.double>
+// CIR: %[[IMAG:.*]] = cir.load{{.*}} %[[REAL_PTR]] : !cir.ptr<!cir.double>, !cir.double
+// CIR: cir.store{{.*}} %[[IMAG]], %[[INIT]] : !cir.double, !cir.ptr<!cir.double>
+
+// LLVM: %[[COMPLEX:.*]] = alloca { double, double }, i64 1, align 8
+// LLVM: %[[INIT:.*]] = alloca double, i64 1, align 8
+// LLVM: %[[IMAG_PTR:.*]] = getelementptr inbounds nuw { double, double }, ptr %[[COMPLEX]], i32 0, i32 1
+// LLVM: %[[IMAG:.*]] = load double, ptr %[[IMAG_PTR]], align 8
+// LLVM: store double %[[IMAG]], ptr %[[INIT]], align 8
+
+// OGCG: %[[COMPLEX:.*]] = alloca { double, double }, align 8
+// OGCG: %[[INIT:.*]] = alloca double, align 8
+// OGCG: %[[IMAG_PTR:.*]] = getelementptr inbounds nuw { double, double }, ptr %[[COMPLEX]], i32 0, i32 1
+// OGCG: %[[IMAG:.*]] = load double, ptr %[[IMAG_PTR]], align 8
+// OGCG: store double %[[IMAG]], ptr %[[INIT]], align 8

[bcardosolopes]

This might look a bit different given the redesign of the other pieces, so I'm gonna hold on reviewing this for now, let me know when this is ready again.

[AmrDeveloper]

This PR is ready to review now with the new design from the incubator @bcardosolopes @andykaylor

[andykaylor]

Same comments as on real PR. Please add a verifier test.

[andykaylor]

Suggested change

	// Note that we have to ask E because Op might be an l-value that
	// Note that we have to ask `e` because `op` might be an l-value that