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Re: [PATCH, tree-optimization]: Fix PR 35085, gcc.dg/vect/vect-iv-9.c fails
- From: "Richard Guenther" <richard dot guenther at gmail dot com>
- To: "Uros Bizjak" <ubizjak at gmail dot com>
- Cc: "GCC Patches" <gcc-patches at gcc dot gnu dot org>
- Date: Thu, 7 Feb 2008 15:03:32 +0100
- Subject: Re: [PATCH, tree-optimization]: Fix PR 35085, gcc.dg/vect/vect-iv-9.c fails
- References: <5787cf470802070555w29a3a1e3oeb23d524ddeca955@mail.gmail.com>
On Feb 7, 2008 2:55 PM, Uros Bizjak <ubizjak@gmail.com> wrote:
> Hello!
>
> As explained in the PR, sometimes we enter rewrite_expr_tree with
> operands in the "wrong" order to detect reduction sum opportunity:
>
> (working):
> +++ OP1: D.2002_7
> op1 rank: 327681
> ->not phi for stmt
> +++ OP2: i_18
> op2 rank: 327680
> not phi for stmt
> +++ OP3: s_17
> op3 rank: 327680
> phi for stmt
>
> (failed):
> +++ OP1: D.2020_7
> op1 rank: 327681
> ->not phi for stmt
> +++ OP2: s_18
> op2 rank: 327680
> phi for stmt
> +++ OP3: i_17
> op3 rank: 327680
> not phi for stmt
>
> Following the logic in reduction detection on op3, we simply try the
> detection and processing on op2.
>
> The patch was bootstrapped and regression tested on i686-pc-linux-gnu.
> The patch reportedly fix the failure.
>
> 2008-02-07 Uros Bizjak <ubizjak@gmail.com>
>
> PR tree-optimization/35085
> * tree-ssa-reassoc.c (rewrite_expr_tree): Enable destructive update
> for operand entry oe2 in addition to operand entry oe3 in order to
> expose more opportunities for vectorizer sum reduction.
>
> OK for mainline?
Ok.
Thanks,
Richard.
> Uros.
>