public inbox for gcc-patches@gcc.gnu.org
 help / color / mirror / Atom feed
From: Richard Biener <rguenther@suse.de>
To: gcc-patches@gcc.gnu.org
Subject: [PATCH] Improve vector_vector_composition_type
Date: Fri, 23 Jun 2023 08:44:16 +0200 (CEST)	[thread overview]
Message-ID: <20230623064417.598501331F@imap2.suse-dmz.suse.de> (raw)

We sometimes get to ask to decompose, say V2DFmode into two halves.
Currently this results in composing it from two DImode pieces
instead of the obvious two DFmode pieces.  The following adjusts
vector_vector_composition_type for this trivial case and avoids
a VIEW_CONVERT_EXPR in the initial code generation.

Bootstrapped and tested on x86_64-unknown-linux-gnu, pushed.

	* tree-vect-stmts.cc (vector_vector_composition_type):
	Handle composition of a vector from a number of elements that
	happens to match its number of lanes.
---
 gcc/tree-vect-stmts.cc | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/gcc/tree-vect-stmts.cc b/gcc/tree-vect-stmts.cc
index ae24f3e66e6..9e046ced7c6 100644
--- a/gcc/tree-vect-stmts.cc
+++ b/gcc/tree-vect-stmts.cc
@@ -2143,6 +2143,14 @@ vector_vector_composition_type (tree vtype, poly_uint64 nelts, tree *ptype)
   if (!VECTOR_MODE_P (vmode))
     return NULL_TREE;
 
+  /* When we are asked to compose the vector from its components let
+     that happen directly.  */
+  if (known_eq (TYPE_VECTOR_SUBPARTS (vtype), nelts))
+    {
+      *ptype = TREE_TYPE (vtype);
+      return vtype;
+    }
+
   poly_uint64 vbsize = GET_MODE_BITSIZE (vmode);
   unsigned int pbsize;
   if (constant_multiple_p (vbsize, nelts, &pbsize))
-- 
2.35.3

                 reply	other threads:[~2023-06-23  6:44 UTC|newest]

Thread overview: [no followups] expand[flat|nested]  mbox.gz  Atom feed

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20230623064417.598501331F@imap2.suse-dmz.suse.de \
    --to=rguenther@suse.de \
    --cc=gcc-patches@gcc.gnu.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).