https://gcc.gnu.org/bugzilla/show_bug.cgi?id=109442
Bug ID: 109442
Summary: Dead local copy of std::vector not removed from
function
Product: gcc
Version: unknown
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: tree-optimization
Assignee: unassigned at gcc dot gnu.org
Reporter: hiraditya at msn dot com
Target Milestone: ---
T vat1(std::vector<T> v1) {
auto v = v1;
return 10;
}
g++ -O3 -std=c++20 -fno-exceptions
vat1(std::vector<int, std::allocator<int> >):
mov rax, QWORD PTR [rdi+8]
sub rax, QWORD PTR [rdi]
je .L11
push rbp
mov rbp, rax
movabs rax, 9223372036854775804
push rbx
sub rsp, 8
cmp rax, rbp
jb .L15
mov rbx, rdi
mov rdi, rbp
call operator new(unsigned long)
mov rsi, QWORD PTR [rbx]
mov rdx, QWORD PTR [rbx+8]
mov rdi, rax
sub rdx, rsi
cmp rdx, 4
jle .L16
call memmove
mov rdi, rax
.L6:
mov rsi, rbp
call operator delete(void*, unsigned long)
add rsp, 8
mov eax, 10
pop rbx
pop rbp
ret
.L11:
mov eax, 10
ret
.L15:
call std::__throw_bad_array_new_length()
.L16:
jne .L6
mov eax, DWORD PTR [rsi]
mov DWORD PTR [rdi], eax
jmp .L6
