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Ping[2]: [PATCH v2] PR tree-optimization/55079: Don't remove all exits of a loop during loop unroll
Ping!
Siddhesh
On Wed, Nov 21, 2012 at 12:42:13PM +0530, Siddhesh Poyarekar wrote:
> Hi,
>
> Ping!
>
>
> Siddhesh
>
> On Thu, 15 Nov 2012 19:05:38 +0530, Siddhesh wrote:
>
> > Hi,
> >
> > Here's an updated version of the patch which warns the user if the
> > removing of redundant exits results in an infinite loop. I have added
> > an additional flag in struct loop called external_exits to record if
> > an exit edge is moved outside the loop body. This currently happens
> > in the loop-unswitch pass and was the root cause of the regression in
> > torture/pr49518.c that I talked about earlier. The patch now passes
> > all regression tests except a mudflap case (fail37-frag). The test is
> > already broken due to removal of all exits so I haven't attempted to
> > fix it as part of this patch. How does this version look?
> >
> > Regards,
> > Siddhesh
> >
> > gcc/ChangeLog:
> >
> > * cfgloop.h (struct loop): New member EXTERNAL_EXITS.
> > * tree-ssa-loop-ivcanon.c (remove_redundant_iv_tests) Warn
> > when loop is left without any exits.
> > * tree-ssa-loop-unswitch.c (tree_unswitch_single_loop): Set
> > EXTERNAL_EXITS when moving a statement with an exit edge out
> > of the loop body.
>