1; RUN: llc -relocation-model=static -verify-machineinstrs -O2 < %s | FileCheck %s 2 3; The call to function TestBar should be a tail call, when in C++ the string 4; `ret` is RVO returned. 5; string TestFoo() { 6; string ret = undef; 7; TestBar(&ret); // tail call optimized 8; return ret; 9; } 10 11target triple = "powerpc64le-linux-gnu" 12 13%class.basic_string.11.42.73 = type { %"class.__gnu_cxx::__versa_string.10.41.72" } 14%"class.__gnu_cxx::__versa_string.10.41.72" = type { %"class.__gnu_cxx::__sso_string_base.9.40.71" } 15%"class.__gnu_cxx::__sso_string_base.9.40.71" = type { %"struct.__gnu_cxx::__vstring_utility<char, std::char_traits<char>, std::allocator<char> >::_Alloc_hider.7.38.69", i64, %union.anon.8.39.70 } 16%"struct.__gnu_cxx::__vstring_utility<char, std::char_traits<char>, std::allocator<char> >::_Alloc_hider.7.38.69" = type { ptr } 17%union.anon.8.39.70 = type { i64, [8 x i8] } 18 19declare void @TestBaz(ptr noalias sret(%class.basic_string.11.42.73) %arg) 20 21define dso_local void @TestBar(ptr noalias sret(%class.basic_string.11.42.73) %arg) { 22bb: 23 call void @TestBaz(ptr noalias sret(%class.basic_string.11.42.73) %arg) 24 ret void 25} 26 27define dso_local void @TestFoo(ptr noalias sret(%class.basic_string.11.42.73) %arg) { 28; CHECK-LABEL: TestFoo: 29; CHECK: #TC_RETURNd8 TestBar 0 30bb: 31 %tmp = getelementptr inbounds %class.basic_string.11.42.73, ptr %arg, i64 0, i32 0, i32 0, i32 2 32 store ptr %tmp, ptr %arg, align 8 33 tail call void @llvm.memcpy.p0.p0.i64(ptr %tmp, ptr nonnull undef, i64 13, i1 false) 34 %tmp3 = getelementptr inbounds %class.basic_string.11.42.73, ptr %arg, i64 0, i32 0, i32 0, i32 1 35 store i64 13, ptr %tmp3, align 8 36 %tmp4 = getelementptr inbounds %class.basic_string.11.42.73, ptr %arg, i64 0, i32 0, i32 0, i32 2, i32 1, i64 5 37 store i8 0, ptr %tmp4, align 1 38 tail call void @TestBar(ptr noalias sret(%class.basic_string.11.42.73) %arg) 39 ret void 40} 41 42; Function Attrs: argmemonly nounwind 43declare void @llvm.memcpy.p0.p0.i64(ptr nocapture, ptr nocapture readonly, i64, i1) #0 44 45attributes #0 = { argmemonly nounwind } 46