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Re: PATCH: PR 16590
On Tue, 2004-08-31 at 00:31, Mark Mitchell wrote:
> Jeffrey A Law wrote:
>
> >On Sun, 2004-08-29 at 13:41, Mark Mitchell wrote:
> >
> >
> >>This PR is a case where GCSE creates an invalid REG_EQUAL note. (More
> >>details are in the audit trail.) I asked Jeff Law for his thoughts on
> >>this patch about ten days ago, but haven't heard back, so I'm going
> >>ahead and checking this in.
> >>
> >>Tested on i686-pc-linux-gnu, applied on the 3.4 branch and on the
> >>mainline.
> >>
> >>
> >Sorry, I didn't expect the cross-town move to leave me without an
> >internet connection for so long.
> >
> >I haven't followed all the changes to gcse which arrange for it
> >to create REG_EQUAL notes. However, I do know most of those changes
> >were done in an attempt to improve later optimizations, so it's
> >possible your change is pessimizing code in some ways.
> >
> >But more importantly, I don't see how that REG_EQUAL note is
> >incorrect.
> >
> OK, I have reverted the patch on the 3.4 branch and on the mainline.
Funny -- the store motion code already has all the bits to find and
remove REG_EQUAL notes which have become invalid. A minor bug in
that code is preventing us from finding the bogus note in this
particular case.
It'll take several hours to fully test the patch, but I do not
expect any problems.
jeff