[PATCH] flow.c cleanup

[Zack Weinberg]

Zdenek Dvorak <rakdver@atrey.karlin.mff.cuni.cz> writes:

> Hello,
>
> the patch below is cleanup of flow.c; it splits more or less unrelated
> tasks (log links creation, pre/post modify transformation, ...) out
> of liveness analysis.
>
> This results in more passes though insns and significant slow down of
> compiler (about 20%). To counter this, I extract the neccesary
> information about insn (set and used registers, ...) and recompute this
> information only if the insn changes.

I am dubious about storing this information in a lookaside table.  It
appears to be used by many passes; it seems to me that it is properly
part of the RTL.  It also seems to me that it duplicates existing
functionality, i.e. the EXPR_LIST and INSN_LIST chains that some
passes attach to RTL.  Could you please look into using the existing
data and/or augmenting it to serve this purpose?

zw