[Gcl-devel] Re: sibling call optimization

[Jim Wilson]

Camm Maguire wrote:
> Greetings, and thanks!  Any idea why the example file wasn't optimized
> with -O3 (but with -O2), and/or on some method whereby I can instruct
> gcc to inform me when the optimization was made?

The example file can't be compiled, so it is imposible to say.  All I 
can do is state the obvious, -O3 enables -finline-functions, so function 
inlining must be interferring with sibling call optimizations somehow.

There is apparently no way to tell when the optimization is made.  Many 
optimization passes emit a message to the dump file when they succeed in 
doing something, but sibcall.c does not.  At the place where it sets 
successful_replacement, we could emit a message to the dump file.  Or 
alternatively, we could increment a counter, and print the total count 
after the pass is finished.  You could submit a bugzilla bug report 
requesting this feature, or you could try writing it yourself.
-- 
Jim Wilson, GNU Tools Support, http://www.SpecifixInc.com