From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: by sourceware.org (Postfix, from userid 48) id F39B2385B539; Fri, 17 Feb 2023 17:33:08 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org F39B2385B539 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gcc.gnu.org; s=default; t=1676655189; bh=qLcX9dTZ8CZXwufXnPsrnHi8kp6KLhDIIQ4PYLFh7WE=; h=From:To:Subject:Date:In-Reply-To:References:From; b=jR+GkRUkkiIenlkKQSriQylOzmi/96uZ0oCOHHbpQ6Rdgy6rQQGHxOQfQac2OsMdV oJse2XNkLzS4WeRBJkzgoA+zSlDcvVDADjmU7igqCbHdhbyhH+lGWJTI+Fniy7SaJK dy7WLTsYDowrZsRf52ElcN5TQYMmwTcr4lRk8BIo= From: "segher at gcc dot gnu.org" To: gcc-bugs@gcc.gnu.org Subject: [Bug rtl-optimization/107949] PPC: Unnecessary rlwinm after lbzx Date: Fri, 17 Feb 2023 17:33:08 +0000 X-Bugzilla-Reason: CC X-Bugzilla-Type: changed X-Bugzilla-Watch-Reason: None X-Bugzilla-Product: gcc X-Bugzilla-Component: rtl-optimization X-Bugzilla-Version: 12.2.0 X-Bugzilla-Keywords: missed-optimization X-Bugzilla-Severity: normal X-Bugzilla-Who: segher at gcc dot gnu.org X-Bugzilla-Status: NEW X-Bugzilla-Resolution: X-Bugzilla-Priority: P3 X-Bugzilla-Assigned-To: unassigned at gcc dot gnu.org X-Bugzilla-Target-Milestone: --- X-Bugzilla-Flags: X-Bugzilla-Changed-Fields: Message-ID: In-Reply-To: References: Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable X-Bugzilla-URL: http://gcc.gnu.org/bugzilla/ Auto-Submitted: auto-generated MIME-Version: 1.0 List-Id: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=3D107949 --- Comment #6 from Segher Boessenkool --- We generate loads into QImode regs, so we need to explicitly convert it to whatever larger mode is wanted later. We also have define_insns to do a zero-extended load directly into a bigger pseudo, but that isn't used apparently. This is one instance of a much more generic problem; on rs6000 this is usually observed as SImode being extended to DImode more often than needed / wanted.=