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Re: C compile time
- From: dewar at gnat dot com (Robert Dewar)
- To: dberlin at dberlin dot org, dewar at gnat dot com
- Cc: coyote at coyotegulch dot com, dhazeghi at yahoo dot com, gcc at gcc dot gnu dot org,pkoning at equallogic dot com
- Date: Mon, 30 Jun 2003 10:25:33 -0400 (EDT)
- Subject: Re: C compile time
> It would be better to improve GDB than to dumb down gcc's optimizations.
> Also work on merging things like var-tracking and dwarf2 location list
> support from the rtlopt-branch/cfg-branch for gcc, which helps immensely
> with optimized debugging.
Yes, but you still get transformations in the optimized code that cannot
be followed by the debugger in a clearly inteligent way.
I am not talking about dumbing down -O here, but rather in practice making
-O0 better.
In our world at least, people use -O0 primarily because they can
't debug at higher levels. Yes, it would be nice if this is fixed,
but it would also be nice if there was a debuggable level which did
not generate so much junk.
In comparison with other compilers, the performance in unoptimized, clearly
debuggable mode of gcc is rather poor, even if the -O2 code compares
favorably.