https://gcc.gnu.org/bugzilla/show_bug.cgi?id=107161
Bug ID: 107161
Summary: gcc doesn't constant fold member if any other member
is mutable
Product: gcc
Version: 12.2.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c++
Assignee: unassigned at gcc dot gnu.org
Reporter: vanyacpp at gmail dot com
Target Milestone: ---
On this code:
struct mytype
{
int a;
mutable int b;
};
extern mytype const p = {1, 2};
int foo()
{
return p.a + 10;
}
int bar()
{
return p.b + 10;
}
GCC -O2 generates:
foo():
mov eax, DWORD PTR p[rip]
add eax, 10
ret
bar():
mov eax, DWORD PTR p[rip+4]
add eax, 10
ret
While clang folds "p.a + 10" into 11:
foo(): # @foo()
mov eax, 11
ret
bar(): # @bar()
mov eax, dword ptr [rip + p+4]
add eax, 10
ret
I think GCC should do the same.
