Hi,
I was just upgrading from gcc-2.95 to gcc-3.3.4 (yeah, I'm way behind).
While recompiling my favorite package (Wireless Tools for Linux), I noticed that
gcc was giving me many warning of the type "warning: inlining failed". And the
resulting binary were bigger than with the previous version of gcc.
My package is used in various embedded systems, therefore I compile with -Os
and always watch the size.
Then, I added "__attribute__((always_inline))" to my code, recompiled with
gcc-3.3.4, and the resulting binary was 150B *smaller* than the default
gcc-3.3.4 compile, which is almost a 1% saving (with no loss of functionality).
So, the new inline behaviour is making the binary bigger.
I personally prefer to defer optimisations to compiler, and I would prefer
not to tag functions inline, but I've noticed that gcc is not capable of
automatically inlining functions that have a single call site. And the new
heuristic make it even more difficult to happen properly, I don't really like
the idea of adding "__attribute__((always_inline))" everywhere.
I would actually like gcc to automatically inline static functions with a
single call site, possibly even if they are not marked inline, as keeping track
of all the call sites of all functions is pretty tedious...
Thanks in advance...
Jean
--
Summary: New inline heuristic make binary bigger (single call
site)
Product: gcc
Version: 3.3.4
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c
AssignedTo: unassigned at gcc dot gnu dot org
ReportedBy: jt at hpl dot hp dot com
CC: gcc-bugs at gcc dot gnu dot org
GCC build triplet: i386-linux
GCC host triplet: i386-linux
GCC target triplet: i386-linux
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=18213
