http://gcc.gnu.org/bugzilla/show_bug.cgi?id=57182
Bug #: 57182
Summary: Documentation implies -fprofile-arcs required to
create .text.unlikely sections
Classification: Unclassified
Product: gcc
Version: unknown
Status: UNCONFIRMED
Severity: minor
Priority: P3
Component: c
AssignedTo: [email protected]
ReportedBy: [email protected]
>From info file (unchanged since before 4.4):
`-freorder-functions'
Reorder functions in the object file in order to improve code
locality. This is implemented by using special subsections
`.text.hot' for most frequently executed functions and
`.text.unlikely' for unlikely executed functions. Reordering is
done by the linker so object file format must support named
sections and linker must place them in a reasonable way.
Also profile feedback must be available in to make this option
effective. See `-fprofile-arcs' for details.
But -freorder-functions creates those sections without -fprofile-arcs for
functions with attributes "hot" or "cold". So the last paragraph is
misleading/obsolete. Does it really mean:
The compiler relies on function attributes or profile feedback to
determine how frequently functions are executed. See `-fprofile-arcs'
for details.
?
Thanks,
Rusty.
