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From: "vries at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug target/105075] [nvptx] Generate sad insn (sum of absolute differences)
Date: Mon, 28 Mar 2022 08:13:26 +0000	[thread overview]
Message-ID: <bug-105075-4-77m1OeRQcF@http.gcc.gnu.org/bugzilla/> (raw)
In-Reply-To: <bug-105075-4@http.gcc.gnu.org/bugzilla/>

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=105075

--- Comment #2 from Tom de Vries <vries at gcc dot gnu.org> ---
AFAIU, at gimple level support is limited to vectors, so that doesn't help to
generate the insn for the simple, scalar case.

It would be nice if combine could generate it and we wouldn't have to use a
peephole, but AFAIU the pattern is too complex for that.

I wonder if reformulating using a conditional could help there (ptx isa
describes semantics using "c + ((a<b) ? b-a : a-b)".

Also, I wonder if defining a stepping-stone intermediate pattern could help
combine.

  parent reply	other threads:[~2022-03-28  8:13 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-03-28  7:53 [Bug target/105075] New: " vries at gcc dot gnu.org
2022-03-28  8:08 ` [Bug target/105075] " vries at gcc dot gnu.org
2022-03-28  8:13 ` vries at gcc dot gnu.org [this message]
2022-03-28  8:24 ` vries at gcc dot gnu.org
2022-03-28  9:50 ` tschwinge at gcc dot gnu.org
2022-03-28 10:15 ` rguenth at gcc dot gnu.org
2022-03-28 13:06 ` vries at gcc dot gnu.org
2022-03-28 13:15 ` rguenther at suse dot de

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