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 7DC963857C49; Thu,  7 Apr 2022 09:43:17 +0000 (GMT)
DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org 7DC963857C49
From: "marxin at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug ipa/105193] New: Code divergence based on -fdump-tree-* since
 r9-5080-gf7293b9dfab5e6e7
Date: Thu, 07 Apr 2022 09:43:17 +0000
X-Bugzilla-Reason: CC
X-Bugzilla-Type: new
X-Bugzilla-Watch-Reason: None
X-Bugzilla-Product: gcc
X-Bugzilla-Component: ipa
X-Bugzilla-Version: 12.0
X-Bugzilla-Keywords: 
X-Bugzilla-Severity: normal
X-Bugzilla-Who: marxin 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 cc target_milestone
Message-ID: <bug-105193-4@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: Thu, 07 Apr 2022 09:43:17 -0000

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=3D105193

            Bug ID: 105193
           Summary: Code divergence based on -fdump-tree-* since
                    r9-5080-gf7293b9dfab5e6e7
           Product: gcc
           Version: 12.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: ipa
          Assignee: unassigned at gcc dot gnu.org
          Reporter: marxin at gcc dot gnu.org
                CC: hubicka at gcc dot gnu.org, marxin at gcc dot gnu.org
  Target Milestone: ---

The following code diverges:

$ cat NodeImpl.ii
struct NodeImpl {
  virtual bool isAttrImpl();
  void deleteIf();
  virtual int getOwnerDocument();
  void unreferenced();
  bool isOwned();
};
struct AttrImpl : NodeImpl {
  bool isAttrImpl();
};
bool NodeImpl::isAttrImpl() { return false; }
NodeImpl *deleteIf_thisNode;
void NodeImpl::deleteIf() {
  if (isOwned())
    return;
  isAttrImpl();
  ((AttrImpl *)deleteIf_thisNode)->getOwnerDocument();
}
void NodeImpl::unreferenced() { deleteIf(); }

$ g++ -O2 NodeImpl.ii -c -S -o 1.s -fdump-tree-all=3D/dev/null && g++ -O2
NodeImpl.ii -c -S -o 2.s && diff -u [12].s
--- 1.s 2022-04-07 11:43:05.995744783 +0200
+++ 2.s 2022-04-07 11:43:06.023744659 +0200
@@ -27,8 +27,10 @@
        testb   %al, %al
        jne     .L3
        movq    0(%rbp), %rax
-       movq    %rbp, %rdi
-       call    *(%rax)
+       movq    (%rax), %rax
+       cmpq    $_ZN8NodeImpl10isAttrImplEv, %rax
+       jne     .L10
+.L5:
        movq    deleteIf_thisNode(%rip), %rdi
        popq    %rbp
        .cfi_remember_state
@@ -41,8 +43,16 @@
 .L3:
        .cfi_restore_state
        popq    %rbp
+       .cfi_remember_state
        .cfi_def_cfa_offset 8
        ret
+       .p2align 4,,10
+       .p2align 3
+.L10:
+       .cfi_restore_state
+       movq    %rbp, %rdi
+       call    *%rax
+       jmp     .L5
        .cfi_endproc
 .LFE1:
        .size   _ZN8NodeImpl8deleteIfEv, .-_ZN8NodeImpl8deleteIfEv=