https://gcc.gnu.org/bugzilla/show_bug.cgi?id=125772
Bug ID: 125772
Summary: Function call not getting inlined for ptr to member
function
Product: gcc
Version: 15.2.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c++
Assignee: unassigned at gcc dot gnu.org
Reporter: elias.oezcan at sap dot com
CC: aaron.puchert at sap dot com
Target Milestone: ---
The following code:
#include <algorithm>
struct S {
int a;
bool cond() const noexcept { return a >= 4;}
};
bool foo(const S* s, size_t l) {
return std::none_of(s, s + l,
[c = &S::cond](const S& x) {
return (x.*c)();
});
}
compiles with -O2 to (x86-64 gcc 15.2):
S::cond() const:
cmp DWORD PTR [rdi], 3
setg al
ret
foo(S const*, unsigned long):
push r12
push rbp
lea rbp, [rdi+rsi*4]
push rbx
mov rbx, rdi
cmp rbp, rdi
je .L4
mov rax, rbp
sub rax, rdi
sub rax, 4
shr rax, 2
add rax, 1
and eax, 3
je .L5
cmp rax, 1
je .L16
cmp rax, 2
je .L17
call S::cond() const
test al, al
jne .L4
...
The original function, that surfaced this looked like this:
bool foo(const S* s, size_t l) {
return std::none_of(s, s + l, std::mem_fn(&S::isErrorOrWorse));
}
I don't see why the function call can't be inlined. The call doesn't seem to
get inlined for any x86-64 gcc compiler.
