This is the mail archive of the
gcc@gcc.gnu.org
mailing list for the GCC project.
Re: Mainline bug in RTL fwprop.
On Tue, 2007-03-06 at 18:18 +0100, Paolo Bonzini wrote:
> > It would be really sweet if we propagated the 'di - 4' into insn 8, then
> > recognized that di is now the value of SI 58, and propagated di into the
> > compare. insn 7 would be dead and we'd get the code the PR is looking
> > for :-)
>
> Unfortunately there's no hope of that because fwprop doesn't do value
> numbering, but I'll try to look at it because it's a wrong code bug.
> (It would be great if you had a testcase for mainline...).
Apply the small patch to mainline which I attached to the note (it only
causes tree-ssa-ter.c to be recompiled), and the provided 2 line
testcase causes this situation.
I plan to check the patch in, but not until this wrong code bug is
resolved.
Andrew