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From: "segher at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org> To: gcc-bugs@gcc.gnu.org Subject: [Bug target/102239] powerpc suboptimal boolean test of contiguous bits Date: Thu, 09 Sep 2021 19:40:54 +0000 [thread overview] Message-ID: <bug-102239-4-79c1koQsqO@http.gcc.gnu.org/bugzilla/> (raw) In-Reply-To: <bug-102239-4@http.gcc.gnu.org/bugzilla/> https://gcc.gnu.org/bugzilla/show_bug.cgi?id=102239 Segher Boessenkool <segher at gcc dot gnu.org> changed: What |Removed |Added ---------------------------------------------------------------------------- Last reconfirmed| |2021-09-09 Ever confirmed|0 |1 Status|UNCONFIRMED |NEW --- Comment #1 from Segher Boessenkool <segher at gcc dot gnu.org> --- Confirmed. So the relevant insn (parallel [(set (reg:CC 123) (compare:CC (and:DI (reg:DI 124) (const_int 25769803776 [0x600000000])) (const_int 0 [0]))) (clobber (scratch:DI))]) is matched by *and<mode>3_2insn but not by any pattern that ends up as just one insn. Not *and<mode>3_mask_dot, because that doesn't do a shift first, is just an AND and there are no machine insns to do that; but there is no pattern for what we can do. *rotl<mode>3_mask_dot cannot do this either; the base and the dot2 of that cannot be done, they return a shifted result, but that doesn't matter for comparing it to 0. So we should add a specialised version.
next prev parent reply other threads:[~2021-09-09 19:40 UTC|newest] Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top 2021-09-08 11:55 [Bug c/102239] New: " npiggin at gmail dot com 2021-09-09 19:40 ` segher at gcc dot gnu.org [this message] 2021-11-24 7:17 ` [Bug target/102239] " luoxhu at gcc dot gnu.org 2021-11-24 23:22 ` segher at gcc dot gnu.org 2021-11-26 8:50 ` luoxhu at gcc dot gnu.org 2021-11-26 15:53 ` segher at gcc dot gnu.org 2021-11-29 3:31 ` luoxhu at gcc dot gnu.org 2021-11-29 6:36 ` luoxhu at gcc dot gnu.org 2021-11-29 10:05 ` segher at gcc dot gnu.org 2021-11-30 5:28 ` luoxhu at gcc dot gnu.org 2021-11-30 22:59 ` segher at gcc dot gnu.org 2021-12-01 7:46 ` luoxhu at gcc dot gnu.org 2022-01-11 9:23 ` cvs-commit at gcc dot gnu.org 2022-01-12 0:27 ` luoxhu at gcc dot gnu.org
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