From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <gcc-bugzilla@gcc.gnu.org>
Received: by sourceware.org (Postfix, from userid 48)
 id DB56A3858C60; Tue, 21 Dec 2021 01:42:31 +0000 (GMT)
DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org DB56A3858C60
From: "guihaoc at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug target/103784] New: suboptimal code for returning bool value on
 target ppc
Date: Tue, 21 Dec 2021 01:42:31 +0000
X-Bugzilla-Reason: CC
X-Bugzilla-Type: new
X-Bugzilla-Watch-Reason: None
X-Bugzilla-Product: gcc
X-Bugzilla-Component: target
X-Bugzilla-Version: 12.0
X-Bugzilla-Keywords: 
X-Bugzilla-Severity: normal
X-Bugzilla-Who: guihaoc at gcc dot gnu.org
X-Bugzilla-Status: UNCONFIRMED
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: bug_id short_desc product version bug_status
 bug_severity priority component assigned_to reporter target_milestone
Message-ID: <bug-103784-4@http.gcc.gnu.org/bugzilla/>
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
X-BeenThere: gcc-bugs@gcc.gnu.org
X-Mailman-Version: 2.1.29
Precedence: list
List-Id: Gcc-bugs mailing list <gcc-bugs.gcc.gnu.org>
List-Unsubscribe: <https://gcc.gnu.org/mailman/options/gcc-bugs>,
 <mailto:gcc-bugs-request@gcc.gnu.org?subject=unsubscribe>
List-Archive: <https://gcc.gnu.org/pipermail/gcc-bugs/>
List-Post: <mailto:gcc-bugs@gcc.gnu.org>
List-Help: <mailto:gcc-bugs-request@gcc.gnu.org?subject=help>
List-Subscribe: <https://gcc.gnu.org/mailman/listinfo/gcc-bugs>,
 <mailto:gcc-bugs-request@gcc.gnu.org?subject=subscribe>
X-List-Received-Date: Tue, 21 Dec 2021 01:42:32 -0000

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=3D103784

            Bug ID: 103784
           Summary: suboptimal code for returning bool value on target ppc
           Product: gcc
           Version: 12.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: target
          Assignee: unassigned at gcc dot gnu.org
          Reporter: guihaoc at gcc dot gnu.org
  Target Milestone: ---

//test.c

#include <stdbool.h>

bool foo (int a, int b)
{
  if (a > 2)
    return false;
  if (b < 10)
    return true;
  return true;
}

//assembly with trunk
        ld 9,0(3)
        cmpdi 0,9,0
        add 10,9,4
        beq 0,.L5
        ldarx 8,0,3
        cmpd 0,8,9
        bne 0,.L4
        stdcx. 10,0,3
        bne 0,.L4
        li 3,1
        rldicl 3,3,0,63
        blr
        .p2align 4,,15
.L5:
        li 3,0
        rldicl 3,3,0,63
        blr

//assembly with at13.0
        subfic 3,3,2
        srdi 3,3,63
        xori 3,3,0x1
        blr

The second branch and two zero extend are unnecessary. If it returns a inte=
ger,
the code seems good.

//test1.c
int foo (int a, int b)
{
  if (a > 2)
    return 0;
  if (b < 10)
    return 1;
  return 1;
}

//assembly with trunk
        li 9,1
        cmpwi 0,3,2
        isel 3,0,9,1
        blr=