Original Message-
> > From: Richard Biener
> > Sent: 14 March 2022 07:38
> > To: GCC Patches
> > Cc: Roger Sayle ; Marc Glisse
> >
> > Subject: Re: [PATCH] PR tree-optimization/101895: Fold VEC_PERM to help
> > recognize FMA.
> >
> >
arget/i386/pr101895.c: New test case.
Thanks in advance,
Roger
--
> -Original Message-
> From: Richard Biener
> Sent: 14 March 2022 07:38
> To: GCC Patches
> Cc: Roger Sayle ; Marc Glisse
>
> Subject: Re: [PATCH] PR tree-optimization/101895: Fold VEC_PERM to help
>
On Sun, Mar 13, 2022 at 12:39 AM Marc Glisse via Gcc-patches
wrote:
>
> On Fri, 11 Mar 2022, Roger Sayle wrote:
>
> +(match vec_same_elem_p
> + CONSTRUCTOR@0
> + (if (uniform_vector_p (TREE_CODE (@0) == SSA_NAME
> +? gimple_assign_rhs1 (SSA_NAME_DEF_STMT (@0)) :
> @0
On Fri, 11 Mar 2022, Roger Sayle wrote:
+(match vec_same_elem_p
+ CONSTRUCTOR@0
+ (if (uniform_vector_p (TREE_CODE (@0) == SSA_NAME
+? gimple_assign_rhs1 (SSA_NAME_DEF_STMT (@0)) : @0
Ah, I didn't remember we needed that, we don't seem to be very consistent
about i
This patch resolves PR tree-optimization/101895 a missed optimization
regression, by adding a constant folding simplification to match.pd to
simplify the transform "mult; vec_perm; plus" into "vec_perm; mult; plus"
with the aim that keeping the multiplication and addition next to each
other allows