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From: "mpolacek at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org> To: gcc-bugs@gcc.gnu.org Subject: [Bug target/105991] New: rldicl+sldi+add generated instead of rldimi Date: Wed, 15 Jun 2022 17:09:34 +0000 [thread overview] Message-ID: <bug-105991-4@http.gcc.gnu.org/bugzilla/> (raw) https://gcc.gnu.org/bugzilla/show_bug.cgi?id=105991 Bug ID: 105991 Summary: rldicl+sldi+add generated instead of rldimi Product: gcc Version: 12.0 Status: UNCONFIRMED Severity: normal Priority: P3 Component: target Assignee: unassigned at gcc dot gnu.org Reporter: mpolacek at gcc dot gnu.org Target Milestone: --- Starting with r12-2731-g96146e61cd7aee, this code (on ppc64le) unsigned long long foo (unsigned long long value) { value &= 0xffffffff; value |= value << 32; return value; } compiled with -O2 generates rldicl 9,3,0,32 sldi 3,3,32 add 3,3,9 blr while previously it was just rldimi 3,3,32,0 blr It doesn't look like a wrong code problem, but it seems more optimal to use rldimi (rotate left, mask insert) rather than rotate left by 0 bits, AND with a mask, shift left, and add.
next reply other threads:[~2022-06-15 17:09 UTC|newest] Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top 2022-06-15 17:09 mpolacek at gcc dot gnu.org [this message] 2022-06-15 17:10 ` [Bug target/105991] [12/13 Regression] " mpolacek at gcc dot gnu.org 2022-06-16 7:57 ` roger at nextmovesoftware dot com 2022-06-16 14:49 ` mpolacek at gcc dot gnu.org 2022-06-16 17:33 ` mpolacek at gcc dot gnu.org 2022-06-18 1:55 ` segher at gcc dot gnu.org 2022-06-18 6:30 ` roger at nextmovesoftware dot com 2022-06-21 23:10 ` cvs-commit at gcc dot gnu.org 2022-06-24 9:49 ` roger at nextmovesoftware dot com 2022-06-24 15:33 ` segher at gcc dot gnu.org 2022-07-04 13:03 ` [Bug target/105991] [12 " cvs-commit at gcc dot gnu.org 2023-04-26 6:56 ` rguenth at gcc dot gnu.org 2023-04-26 8:01 ` roger at nextmovesoftware dot com
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