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From: "bergner at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug target/110320] New: ELFv2 pc-rel ABI extension allows using r2
 as a volatile register
Date: Tue, 20 Jun 2023 13:40:45 +0000
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X-Bugzilla-Product: gcc
X-Bugzilla-Component: target
X-Bugzilla-Version: 14.0
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https://gcc.gnu.org/bugzilla/show_bug.cgi?id=3D110320

            Bug ID: 110320
           Summary: ELFv2 pc-rel ABI extension allows using r2 as a
                    volatile register
           Product: gcc
           Version: 14.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: target
          Assignee: unassigned at gcc dot gnu.org
          Reporter: bergner at gcc dot gnu.org
  Target Milestone: ---

The PC-Relative ABI extension to the ELFv2 ABI defines register r2 (normally
the TOC register in ELFv1 & ELFv2) as a volatile register available for use=
 in
the register allocator.  Currently GCC doesn't make use of that fact, so th=
is
is a missed-optimization opportunity.=