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[Bug tree-optimization/85694] Generation of vectorized AVG (Average) instruction
- From: "rguenth at gcc dot gnu.org" <gcc-bugzilla at gcc dot gnu dot org>
- To: gcc-bugs at gcc dot gnu dot org
- Date: Tue, 08 May 2018 14:29:51 +0000
- Subject: [Bug tree-optimization/85694] Generation of vectorized AVG (Average) instruction
- Auto-submitted: auto-generated
- References: <bug-85694-4@http.gcc.gnu.org/bugzilla/>
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=85694
--- Comment #2 from Richard Biener <rguenth at gcc dot gnu.org> ---
Hmm, but if you have 255 + 255 + 1 then you need to use pavgw at least,
otherwise the vectorization isn't semantically equivalent? Or do the
instructions compute
the intermediate results in greater precision than 8 bits? The specification
doesn't seem to tell.
Can you clarify?