https://gcc.gnu.org/bugzilla/show_bug.cgi?id=116868
Bug ID: 116868
Summary: GCC trunk doesn't eliminate a superfluous new/delete
pair
Product: gcc
Version: unknown
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: middle-end
Assignee: unassigned at gcc dot gnu.org
Reporter: dccitaliano at gmail dot com
Target Milestone: ---
Maybe this is known, but i wasn't able to find the exact duplicate.
(this is the closest I found -- apologies for the churn, if any)
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=78104
https://godbolt.org/z/579rGG95z
#include <vector>
int sumVector() {
const std::vector<int> vec = {1};
int sum = 0;
for (int i = 0; i < vec.size(); i++) {
sum += vec[i];
}
return sum;
}
At -O3 emits:
sumVector():
sub rsp, 8
mov edi, 4
call operator new(unsigned long)
mov esi, 4
mov DWORD PTR [rax], 1
mov rdi, rax
call operator delete(void*, unsigned long)
mov eax, 1
add rsp, 8
ret
I'd expect to emit something like (clang does it):
sumVector():
mov eax, 1
ret
