From: Marc Glisse <marc.glisse@inria.fr>
To: Roger Sayle <roger@nextmovesoftware.com>
Cc: 'GCC Patches' <gcc-patches@gcc.gnu.org>
Subject: Re: [PATCH] PR tree-optimization/101895: Fold VEC_PERM to help recognize FMA.
Date: Sun, 13 Mar 2022 00:39:09 +0100 (CET) [thread overview]
Message-ID: <6ee61d3-ffac-7667-9dc0-692699e9e12f@hippo.saclay.inria.fr> (raw)
In-Reply-To: <032301d835a2$86214110$9263c330$@nextmovesoftware.com>
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 it. Probably for this reason, the transformation "Prefer vector1 <<
scalar to vector1 << vector2" does not match
typedef int vec __attribute__((vector_size(16)));
vec f(vec a, int b){
vec bb = { b, b, b, b };
return a << bb;
}
which is only optimized at vector lowering time.
+/* Push VEC_PERM earlier if that may help FMA perception (PR101895). */
+(for plusminus (plus minus)
+ (simplify
+ (plusminus (vec_perm (mult@0 @1 vec_same_elem_p@2) @0 @3) @4)
+ (plusminus (mult (vec_perm @1 @1 @3) @2) @4)))
Don't you want :s on mult and vec_perm?
--
Marc Glisse
next prev parent reply other threads:[~2022-03-12 23:39 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-03-11 23:48 Roger Sayle
2022-03-12 23:39 ` Marc Glisse [this message]
2022-03-14 7:37 ` Richard Biener
2022-03-15 7:25 ` Roger Sayle
2022-03-15 7:43 ` Richard Biener
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