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Re: [PATCH][RFC] Allow forwprop to propagate into mutliple uses

On Tue, 2005-07-26 at 10:47 +0200, Richard Guenther wrote:
> This patch serves as a temporary fix for the lack of a tree-combiner
> in 4.1.  It allows forwprop to propagate ADDR_EXPRs into multiple
> uses, which helps C++ testcases quite a bit.  I added an (unused) flag
> so that we maybe can restrict this extra propagation to the first
> forwprop pass only.  I will do some benchmarking, if you think that
> such patch may be accepted for 4.1 (my benchmarking sofar was on
> tramp3d only and with array aliasing enabled - with the forwprop
> change we gain ~30% in performance, while without, it does not improve).
> Bootstrapped and tested on x86_64-unknown-linux-gnu.
> Comments?
> Richard.
> 2005-07-26  Richard Guenther  <>
>         * tree-ssa-forwprop.c (forward_propagate_addr_expr): Add
>         argument to tell whether we want to propagate into multiple
>         uses.  Handle this case.
>         (tree_ssa_forward_propagate_single_use_vars): Adjust caller,
>         always propagate into multiple uses for now.
I would suggest waiting -- I don't think this is really appropriate
for stage3.  In fact, it's probably time to create a mega bug for
pending patches....


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