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[Bug middle-end/81914] [7/8 Regression] gcc 7.1 generates branch for code which was branchless in earlier gcc version
- From: "glisse at gcc dot gnu.org" <gcc-bugzilla at gcc dot gnu dot org>
- To: gcc-bugs at gcc dot gnu dot org
- Date: Sat, 16 Dec 2017 11:15:35 +0000
- Subject: [Bug middle-end/81914] [7/8 Regression] gcc 7.1 generates branch for code which was branchless in earlier gcc version
- Auto-submitted: auto-generated
- References: <bug-81914-4@http.gcc.gnu.org/bugzilla/>
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=81914
--- Comment #10 from Marc Glisse <glisse at gcc dot gnu.org> ---
For the particular case of <=> (-1, 0 or 1), I've seen code like (a>b)-(a<b),
which is branchless (IIRC we don't generate optimal code for this either, we
could use sbb or adc).