Files
llvm-project/clang/test/CIR/CodeGen/agg-init-constexpr.cpp
Erich Keane b9e9e7bc5c [CIR] Implement aggregate-expr-init with a const-expr lowering (#190631)
An aggregate initialized by a ConstantExpr happens when you have a
consteval constructor. This patch implements this lowering.

There is a bit of a difference in decisions between classic-codegen and
cir lowering, where classic-codegen will do init-via-GEP, whereas CIR
does either a struct-store, or a memcpy, otherwise these seem identical.

There IS a branch (if emitting a constant-expr fails) that appears dead
to the best of my knowledge, but since classic-codegen does it, I left
the version there. It is at most a pessimisation of the constant-emit
(just emitting the expression), so it shouldn't cause problems.
2026-04-07 06:13:09 -07:00

40 lines
1.7 KiB
C++

// RUN: %clang_cc1 -triple x86_64-unknown-linux-gnu -std=c++20 -fclangir -emit-cir %s -o %t.cir
// RUN: FileCheck --check-prefix=CIR --input-file=%t.cir %s
// RUN: %clang_cc1 -triple x86_64-unknown-linux-gnu -std=c++20 -fclangir -emit-llvm %s -o %t-cir.ll
// RUN: FileCheck --check-prefix=LLVM --input-file=%t-cir.ll %s
// RUN: %clang_cc1 -triple x86_64-unknown-linux-gnu -std=c++20 -emit-llvm %s -o %t.ll
// RUN: FileCheck --check-prefix=OGCG --input-file=%t.ll %s
struct HasVal {
int x = 5;
};
struct WithCtor {
consteval WithCtor(int a, long b) : x(a*a), y(a*b) {}
int x;
long y;
HasVal a;
};
extern "C" void construct() {
WithCtor c(2,5);
}
// CIR-LABEL: construct()
// CIR-NEXT: %[[WC_ALLOCA:.*]] = cir.alloca !rec_WithCtor
// CIR-NEXT: %[[CONST_VAL:.*]] = cir.const #cir.const_record<{#cir.int<4> : !s32i, #cir.int<10> : !s64i, #cir.const_record<{#cir.int<5> : !s32i}> : !rec_HasVal}>
// CIR-NEXT: %[[BITCAST:.*]] = cir.cast bitcast %[[WC_ALLOCA]]
// CIR-NEXT: cir.store{{.*}}%[[CONST_VAL]], %[[BITCAST]]
// LLVM-LABEL: construct()
// LLVM-NEXT: %[[WC_ALLOCA:.*]] = alloca %struct.WithCtor
// LLVM-NEXT: store { i32, i64, %struct.HasVal } { i32 4, i64 10, %struct.HasVal { i32 5 } }, ptr %[[WC_ALLOCA]]
// OGCG-LABEL: construct()
// OGCG: %[[WC_ALLOCA:.*]] = alloca %struct.WithCtor
// OGCG-NEXT: %[[X_GEP:.*]] = getelementptr{{.*}} { i32, i64, %struct.HasVal }, ptr %[[WC_ALLOCA]], i32 0, i32 0
// OGCG-NEXT: store i32 4, ptr %[[X_GEP]]
// OGCG-NEXT: %[[Y_GEP:.*]] = getelementptr{{.*}} { i32, i64, %struct.HasVal }, ptr %[[WC_ALLOCA]], i32 0, i32 1
// OGCG-NEXT: store i64 10, ptr %[[Y_GEP]]
// OGCG-NEXT: %[[A_GEP:.*]] = getelementptr{{.*}} { i32, i64, %struct.HasVal }, ptr %[[WC_ALLOCA]], i32 0, i32 2
// OGCG-NEXT: store %struct.HasVal { i32 5 }, ptr %[[A_GEP]]