[clang] [CIR] Implement ArraySubscript for ComplexType (PR #146283)

[Amr Hesham via cfe-commits]

https://github.com/AmrDeveloper updated https://github.com/llvm/llvm-project/pull/146283

>From a4156a34a0b6b66e0dc2d6cfdef4028861b49600 Mon Sep 17 00:00:00 2001
From: AmrDeveloper <amr96 at programmer.net>
Date: Sun, 29 Jun 2025 20:05:05 +0200
Subject: [PATCH 1/2] [CIR] Implement ArraySubscript for ComplexType

---
 clang/lib/CIR/CodeGen/CIRGenExprComplex.cpp |  5 ++++
 clang/test/CIR/CodeGen/complex.cpp          | 32 +++++++++++++++++++++
 2 files changed, 37 insertions(+)

diff --git a/clang/lib/CIR/CodeGen/CIRGenExprComplex.cpp b/clang/lib/CIR/CodeGen/CIRGenExprComplex.cpp
index 8ee9ce8884c72..6d5a3c7039e0e 100644
--- a/clang/lib/CIR/CodeGen/CIRGenExprComplex.cpp
+++ b/clang/lib/CIR/CodeGen/CIRGenExprComplex.cpp
@@ -39,6 +39,7 @@ class ComplexExprEmitter : public StmtVisitor<ComplexExprEmitter, mlir::Value> {
   void emitStoreOfComplex(mlir::Location loc, mlir::Value val, LValue lv,
                           bool isInit);
 
+  mlir::Value VisitArraySubscriptExpr(Expr *e);
   mlir::Value VisitBinAssign(const BinaryOperator *e);
   mlir::Value VisitCallExpr(const CallExpr *e);
   mlir::Value VisitChooseExpr(ChooseExpr *e);
@@ -119,6 +120,10 @@ void ComplexExprEmitter::emitStoreOfComplex(mlir::Location loc, mlir::Value val,
   builder.createStore(loc, val, destAddr);
 }
 
+mlir::Value ComplexExprEmitter::VisitArraySubscriptExpr(Expr *e) {
+  return emitLoadOfLValue(e);
+}
+
 mlir::Value ComplexExprEmitter::VisitBinAssign(const BinaryOperator *e) {
   mlir::Value value;
   LValue lv = emitBinAssignLValue(e, value);
diff --git a/clang/test/CIR/CodeGen/complex.cpp b/clang/test/CIR/CodeGen/complex.cpp
index 470723b8fc48e..1f56f16df97ae 100644
--- a/clang/test/CIR/CodeGen/complex.cpp
+++ b/clang/test/CIR/CodeGen/complex.cpp
@@ -473,3 +473,35 @@ void foo23(int _Complex a, int _Complex b) {
 // OGCG: %[[RESULT_IMAG_PT:.*]] = getelementptr inbounds nuw { i32, i32 }, ptr %[[RESULT]], i32 0, i32 1
 // OGCG: store i32 %[[B_REAL]], ptr %[[RESULT_REAL_PT]], align 4
 // OGCG: store i32 %[[B_IMAG]], ptr %[[RESULT_IMAG_PT]], align 4
+
+void foo24() {
+  int _Complex arr[2];
+  int _Complex  r = arr[1];
+}
+
+// CIR: %[[ARR:.*]] = cir.alloca !cir.array<!cir.complex<!s32i> x 2>, !cir.ptr<!cir.array<!cir.complex<!s32i> x 2>>, ["arr"]
+// CIR: %[[RESULT:.*]] = cir.alloca !cir.complex<!s32i>, !cir.ptr<!cir.complex<!s32i>>, ["r", init]
+// CIR: %[[IDX:.*]] = cir.const #cir.int<1> : !s32i
+// CIR: %[[ARR_PTR:.*]] = cir.cast(array_to_ptrdecay, %[[ARR]] : !cir.ptr<!cir.array<!cir.complex<!s32i> x 2>>), !cir.ptr<!cir.complex<!s32i>>
+// CIR: %[[RESULT_VAL:.*]] = cir.ptr_stride(%[[ARR_PTR]] : !cir.ptr<!cir.complex<!s32i>>, %[[IDX]] : !s32i), !cir.ptr<!cir.complex<!s32i>>
+// CIR: %[[TMP:.*]] = cir.load{{.*}} %[[RESULT_VAL]] : !cir.ptr<!cir.complex<!s32i>>, !cir.complex<!s32i>
+// CIR: cir.store{{.*}} %[[TMP]], %[[RESULT]] : !cir.complex<!s32i>, !cir.ptr<!cir.complex<!s32i>>
+
+// LLVM: %[[ARR:.*]] = alloca [2 x { i32, i32 }], i64 1, align 16
+// LLVM: %[[RESULT:.*]] = alloca { i32, i32 }, i64 1, align 4
+// LLVM: %[[ARR_PTR:.*]] = getelementptr { i32, i32 }, ptr %[[ARR]], i32 0
+// LLVM: %[[RESULT_VAL:.*]] = getelementptr { i32, i32 }, ptr %[[ARR_PTR]], i64 1
+// LLVM: %[[TMP:.*]] = load { i32, i32 }, ptr %[[RESULT_VAL]], align 8
+// LLVM: store { i32, i32 } %[[TMP]], ptr %[[RESULT]], align 4
+
+// OGCG: %[[ARR:.*]] = alloca [2 x { i32, i32 }], align 16
+// OGCG: %[[RESULT:.*]] = alloca { i32, i32 }, align 4
+// OGCG: %[[ELEM_PTR:.*]] = getelementptr inbounds [2 x { i32, i32 }], ptr %[[ARR]], i64 0, i64 1
+// OGCG: %[[ELEM_REAL_PTR:.*]] = getelementptr inbounds nuw { i32, i32 }, ptr %[[ELEM_PTR]], i32 0, i32 0
+// OGCG: %[[ELEM_REAL:.*]] = load i32, ptr %[[ELEM_REAL_PTR]]
+// OGCG: %[[ELEM_IMAG_PTR:.*]] = getelementptr inbounds nuw { i32, i32 }, ptr %[[ELEM_PTR]], i32 0, i32 1
+// OGCG: %[[ELEM_IMAG:.*]] = load i32, ptr %[[ELEM_IMAG_PTR]]
+// OGCG: %[[RESULT_REAL_PTR:.*]] = getelementptr inbounds nuw { i32, i32 }, ptr %[[RESULT]], i32 0, i32 0
+// OGCG: %[[RESULT_IMAG_PTR:.*]] = getelementptr inbounds nuw { i32, i32 }, ptr %[[RESULT]], i32 0, i32 1
+// OGCG: store i32 %[[ELEM_REAL]], ptr %[[RESULT_REAL_PTR]], align 4
+// OGCG: store i32 %[[ELEM_IMAG]], ptr %[[RESULT_IMAG_PTR]], align 4

>From 4d27b82ab60a913ed2fcf916d0e81b1d66f34782 Mon Sep 17 00:00:00 2001
From: AmrDeveloper <amr96 at programmer.net>
Date: Mon, 30 Jun 2025 18:53:43 +0200
Subject: [PATCH 2/2] Remove extra space

---
 clang/test/CIR/CodeGen/complex.cpp | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/clang/test/CIR/CodeGen/complex.cpp b/clang/test/CIR/CodeGen/complex.cpp
index 1f56f16df97ae..201d5b4020faf 100644
--- a/clang/test/CIR/CodeGen/complex.cpp
+++ b/clang/test/CIR/CodeGen/complex.cpp
@@ -476,7 +476,7 @@ void foo23(int _Complex a, int _Complex b) {
 
 void foo24() {
   int _Complex arr[2];
-  int _Complex  r = arr[1];
+  int _Complex r = arr[1];
 }
 
 // CIR: %[[ARR:.*]] = cir.alloca !cir.array<!cir.complex<!s32i> x 2>, !cir.ptr<!cir.array<!cir.complex<!s32i> x 2>>, ["arr"]