On Fri, 7 May 2021, Kewen.Lin wrote:
> Hi,
>
> This patch is to teach forwprop to optimize some cases where the
> permutated operands of vector permutation are from two same type
> CTOR and CTOR or one CTOR and one VECTOR CST. It aggressively
> takes VIEW_CONVERT_EXPR as trivial copies and transform the vector
> permutation into vector CTOR.
>
> Bootstrapped/regtested on powerpc64le-linux-gnu P9, powerpc64-linux-gnu P8,
> x86_64-redhat-linux and aarch64-linux-gnu.
>
> Is it ok for trunk?
Can you please avoid the changes to get_prop_source_stmt and
can_propagate_from? It should work to add a single match
of a V_C_E after the get_prop_source_stmt call. Ideally
we'd have
/* Shuffle of a constructor. */
else if (code == CONSTRUCTOR || code == VECTOR_CST)
{
...
}
else if (code == VIEW_CONVERT_EXPR)
{
op1 must also be a V_C_E or VECTOR_CST here
}
but then I fear we have no canonicalization of the VECTOR_CST
to 2nd VEC_PERM operand. But then moving the op1 gathering
out of the if (code == CONSTRUCTOR || code == VECTOR_CST)
case (doesn't need an else) might still make such refactoring
possible as first matching
if (code == VIEW_CONVERT_EXPR || code2 == VIEW_CONVERT_EXPR)
{
...
}
else if (code == CONSTRUCTOR || code == VECTOR_CST)
...
I'd appreciate Richard S. comments on the
vec_perm_indices::new_shrinked_vector code.
Thanks,
Richard.
> BR,
> Kewen
> ------
> gcc/ChangeLog:
>
> PR tree-optimization/99398
> * tree-ssa-forwprop.c (get_prop_source_stmt): Add optional argument
> view_conv_prop to indicate whether to take VIEW_CONVERT_EXPR as
> trivial copy. Add handlings for this argument.
> (remove_prop_source_from_use): Likewise.
> (simplify_permutation): Optimize some cases where the fed operands
> are CTOR/CST and propagated through VIEW_CONVERT_EXPR. Add the
> call to vec_perm_indices::new_shrinked_vector.
> * vec-perm-indices.c (vec_perm_indices::new_shrinked_vector): New
> function.
> * vec-perm-indices.h (vec_perm_indices::new_shrinked_vector): New
> declare.
>
> gcc/testsuite/ChangeLog:
>
> PR tree-optimization/99398
> * gcc.target/powerpc/vec-perm-ctor-run.c: New test.
> * gcc.target/powerpc/vec-perm-ctor.c: New test.
> * gcc.target/powerpc/vec-perm-ctor.h: New test.
>
--
Richard Biener <rguent...@suse.de>
SUSE Software Solutions Germany GmbH, Maxfeldstrasse 5, 90409 Nuernberg,
Germany; GF: Felix Imendörffer; HRB 36809 (AG Nuernberg)
