Re: [patch] Remove redundant calls to copy_virtual_operands

[Dorit Nuzman <DORIT@il.ibm.com>]

>
> Currently the vectorizer copies virtual operands from scalar memory
> operations to the corresponding vector operations (that the vectorizer
> creates). This seems to be redundant, since we set memory tags for the
> memory operations that we create and call update_ssa at the end of loop
> vectorization. This patch removes these redundant calls to
> copy_virtual_operands().
>

If I'm not mistaken this patch also fixes an ICE when applied on top of
gcc4.1.1, so not only are these calls apparently redundant, but it seems
that they can also be harmful.

> Bootstrapped and tested on ppc-linux and x86_64-linux.

on x86 it also passed bootstrap with vectorization enabled, right?

> O.K. for mainline?
>

it looks ok to me, but it would be much better if one of the aliasing/vops
experts took a look

thanks,
dorit

> Ira
>
> :ADDPATCH SSA:
>
> ChangeLog entry:
>
>       * tree-vect-transform.c (vectorizable_store): Remove call to
>       copy_virtual_operands() and call mark_symbols_for_renaming() for
>       the created vector store.
>       (vect_setup_realignment): Don't call copy_virtual_operands() and
>       update_vuses_to_preheader().
>       (vectorizable_load): Don't call copy_virtual_operands().
>       (update_vuses_to_preheader): Remove.
>
> (See attached file: copy_vops.txt)[attachment "copy_vops.txt"
> deleted by Dorit Nuzman/Haifa/IBM]