[clang] [CIR] Implement Unary real & imag on scalar expr (PR #159916)

[Amr Hesham via cfe-commits]

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@@ -1001,3 +1001,86 @@ void foo36() {
 // OGCG: %[[A_IMAG_F32:.*]] = fpext half %[[A_IMAG]] to float
 // OGCG: %[[A_IMAG_F16:.*]] = fptrunc float %[[A_IMAG_F32]] to half
 // OGCG: store half %[[A_IMAG_F16]], ptr %[[IMAG_ADDR]], align 2
+
+void foo38() {
+  float a;
+  float b = __real__ 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: cir.store{{.*}} %[[TMP_A]], %[[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 %[[TMP_A]], ptr %[[B_ADDR]], align 4
+
+// OGCG: %[[A_ADDR:.*]] = alloca float, align 4
+// 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 foo39() {
+  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: %[[CONST_ZERO:.*]] = cir.const #cir.fp<0.000000e+00> : !cir.float
+// CIR: cir.store{{.*}} %[[CONST_ZERO]], %[[B_ADDR]] : !cir.float, !cir.ptr<!cir.float>
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AmrDeveloper wrote:

That makes sense, I was thinking maybe instant of emitting new complex with zero imaginary, we can update ComplexRealOp & ComplexImagOp to accept either Complex Element Type (Int or Float), and When we introduce optimization levels we can fold those cases to real or zero if needed 🤔, What do you think @andykaylor @bcardosolopes ? 

https://github.com/llvm/llvm-project/pull/159916