; RUN: llc -relocation-model=static -verify-machineinstrs -O2 < %s | FileCheck %s ; The call to function TestBar should be a tail call, when in C++ the string ; `ret` is RVO returned. ; string TestFoo() { ; string ret = undef; ; TestBar(&ret); // tail call optimized ; return ret; ; } target triple = "powerpc64le-linux-gnu" %class.basic_string.11.42.73 = type { %"class.__gnu_cxx::__versa_string.10.41.72" } %"class.__gnu_cxx::__versa_string.10.41.72" = type { %"class.__gnu_cxx::__sso_string_base.9.40.71" } %"class.__gnu_cxx::__sso_string_base.9.40.71" = type { %"struct.__gnu_cxx::__vstring_utility, std::allocator >::_Alloc_hider.7.38.69", i64, %union.anon.8.39.70 } %"struct.__gnu_cxx::__vstring_utility, std::allocator >::_Alloc_hider.7.38.69" = type { ptr } %union.anon.8.39.70 = type { i64, [8 x i8] } declare void @TestBaz(ptr noalias sret(%class.basic_string.11.42.73) %arg) define dso_local void @TestBar(ptr noalias sret(%class.basic_string.11.42.73) %arg) { bb: call void @TestBaz(ptr noalias sret(%class.basic_string.11.42.73) %arg) ret void } define dso_local void @TestFoo(ptr noalias sret(%class.basic_string.11.42.73) %arg) { ; CHECK-LABEL: TestFoo: ; CHECK: #TC_RETURNd8 TestBar 0 bb: %tmp = getelementptr inbounds %class.basic_string.11.42.73, ptr %arg, i64 0, i32 0, i32 0, i32 2 store ptr %tmp, ptr %arg, align 8 tail call void @llvm.memcpy.p0.p0.i64(ptr %tmp, ptr nonnull undef, i64 13, i1 false) %tmp3 = getelementptr inbounds %class.basic_string.11.42.73, ptr %arg, i64 0, i32 0, i32 0, i32 1 store i64 13, ptr %tmp3, align 8 %tmp4 = getelementptr inbounds %class.basic_string.11.42.73, ptr %arg, i64 0, i32 0, i32 0, i32 2, i32 1, i64 5 store i8 0, ptr %tmp4, align 1 tail call void @TestBar(ptr noalias sret(%class.basic_string.11.42.73) %arg) ret void } ; Function Attrs: argmemonly nounwind declare void @llvm.memcpy.p0.p0.i64(ptr nocapture, ptr nocapture readonly, i64, i1) #0 attributes #0 = { argmemonly nounwind }