http://gcc.gnu.org/bugzilla/show_bug.cgi?id=59639
Bug ID: 59639
Summary: Code in a cold basic block is not pushed to
.text.unlikely
Product: gcc
Version: 4.8.2
Status: UNCONFIRMED
Severity: minor
Priority: P3
Component: tree-optimization
Assignee: unassigned at gcc dot gnu.org
Reporter: a...@cloudius-systems.com
Consider the code:
[[gnu::cold]]
int slow_path();
int f()
{
asm goto ("" : : : : cold);
return 1;
cold:
return slow_path();
}
since slow_path() is cold, the compiler can infer that the basic block
beginning with the cold: label is also cold, so it should be placed in
.text.unlikely. Yet it isn't:
0000000000000000 <_Z1fv>:
0: b8 01 00 00 00 mov $0x1,%eax
5: c3 retq
6: e9 00 00 00 00 jmpq b <_Z1fv+0xb>
Adding a cold attribute to the label doesn't help.
Expected results: the jmpq instruction should be placed in .text.unlikely.
