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Re: [PATCH] Remove define_function_unit
- From: kenner at vlsi1 dot ultra dot nyu dot edu (Richard Kenner)
- To: paolo dot bonzini at polimi dot it
- Cc: gcc-patches at gcc dot gnu dot org
- Date: Tue, 20 Jul 04 08:22:33 EDT
- Subject: Re: [PATCH] Remove define_function_unit
My guess is that it was too expensive. Attribute optimization is
overall quite heavyweight, and the code I took out included some
explicit band-aids that switch from exponential to polynomial complexity
as the description becomes larger. Maybe Kenner knows more, I
understand that he wrote that stuff.
Yeah, but I haven't followed how it's been used with the pipeline stuff.
My feeling is that any optimizations done in genattrtab are worthwhile because
they only cost time in building the compiler, but speed it up, but obviously
this has to be measured. I don't have any strong feeling here either way
(and barely remember the code in question).