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RE: gcc compile-time performance
- From: "Kaveh R. Ghazi" <ghazi at caip dot rutgers dot edu>
- To: dewar at gnat dot com
- Cc: gcc at gcc dot gnu dot org
- Date: Tue, 21 May 2002 23:23:41 -0400 (EDT)
- Subject: RE: gcc compile-time performance
> From: dewar at gnat dot com (Robert Dewar)
> Note that if you really intend to use -O0 to deliver, then the design
> of gcc is quite unfortunate. The amount of code generated by gcc with
> optimization off compares really poorly with other competing
> compilers. It really is very cheap to do at least a little cleaning up
> of code. To see in x86 code repeated cases of a variable being stored
> and immediately loaded from the same location is sad.
> We find almost none of our users delivering in -O0. If this is really
> a pattern in other uses, then I think that's another reason for
> looking at a -O0.5 which would try to do at least a little
> optimziation. I am not even sure this would not speed things up, since
> you would generate smaller assembler files.
> (speed things up = speed up compilation)
I believe the idea of better -O0 is perhaps shared by others. See:
for an example of doing smarter compilation at -O0 and getting smaller
code with a faster compile time.
Kaveh R. Ghazi Director of Systems Architecture
firstname.lastname@example.org Qwest Solutions