[Bug rtl-optimization/100590] New: ICE: verify_flow_info failed (error: too many outgoing branch edges from bb 2)

[Bug rtl-optimization/100590] New: ICE: verify_flow_info failed (error: too many outgoing branch edges from bb 2)

[asolokha at gmx dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100590

            Bug ID: 100590
           Summary: ICE: verify_flow_info failed (error: too many outgoing
                    branch edges from bb 2)
           Product: gcc
           Version: 12.0
            Status: UNCONFIRMED
          Keywords: ice-on-valid-code
          Severity: normal
          Priority: P3
         Component: rtl-optimization
          Assignee: unassigned at gcc dot gnu.org
          Reporter: asolokha at gmx dot com
  Target Milestone: ---

gcc-12.0.0-alpha20210509 snapshot (g:5e0236d3b0e0d7ad98bcee36128433fa755b5558)
and gcc 11.1 ICE when compiling testsuite/gcc.dg/torture/pr100398.c w/ -O1
-fno-dce:

% gcc-12.0.0 -O1 -fno-dce -c gcc/testsuite/gcc.dg/torture/pr100398.c
gcc/testsuite/gcc.dg/torture/pr100398.c: In function 'test5_limit':
gcc/testsuite/gcc.dg/torture/pr100398.c:13:1: error: too many outgoing branch
edges from bb 2
   13 | }
      | ^
during RTL pass: cprop_hardreg
gcc/testsuite/gcc.dg/torture/pr100398.c:13:1: internal compiler error:
verify_flow_info failed
0x9706d3 verify_flow_info()
       
/var/tmp/portage/sys-devel/gcc-12.0.0_alpha20210509/work/gcc-12-20210509/gcc/cfghooks.c:269
0xd2d29a execute_function_todo
       
/var/tmp/portage/sys-devel/gcc-12.0.0_alpha20210509/work/gcc-12-20210509/gcc/passes.c:2054
0xd2dc8b execute_todo
       
/var/tmp/portage/sys-devel/gcc-12.0.0_alpha20210509/work/gcc-12-20210509/gcc/passes.c:2096

It can be a duplicate of PR98619.

[Bug rtl-optimization/100590] [11/12 Regression] ICE: verify_flow_info failed (error: too many outgoing branch edges from bb 2) since r11-5002-ge3b3b59683c1e7d3

[marxin at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100590

Martin Liška <marxin at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
            Summary|ICE: verify_flow_info       |[11/12 Regression] ICE:
                   |failed (error: too many     |verify_flow_info failed
                   |outgoing branch edges from  |(error: too many outgoing
                   |bb 2)                       |branch edges from bb 2)
                   |                            |since
                   |                            |r11-5002-ge3b3b59683c1e7d3
     Ever confirmed|0                           |1
                 CC|                            |marxin at gcc dot gnu.org,
                   |                            |vmakarov at gcc dot gnu.org
             Status|UNCONFIRMED                 |NEW
   Last reconfirmed|                            |2021-05-13

--- Comment #1 from Martin Liška <marxin at gcc dot gnu.org> ---
Started with r11-5002-ge3b3b59683c1e7d3.

[Bug rtl-optimization/100590] [11/12 Regression] ICE: verify_flow_info failed (error: too many outgoing branch edges from bb 2) since r11-5002-ge3b3b59683c1e7d3

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100590

Richard Biener <rguenth at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|---                         |11.2
           Priority|P3                          |P2

[Bug rtl-optimization/100590] [11/12 Regression] ICE: verify_flow_info failed (error: too many outgoing branch edges from bb 2) since r11-5002-ge3b3b59683c1e7d3

[jakub at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100590

Jakub Jelinek <jakub at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|NEW                         |ASSIGNED
           Assignee|unassigned at gcc dot gnu.org      |jakub at gcc dot gnu.org

--- Comment #2 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
Created attachment 50829
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=50829&action=edit
gcc12-pr100590.patch

Untested fix.

[Bug rtl-optimization/100590] [11/12 Regression] ICE: verify_flow_info failed (error: too many outgoing branch edges from bb 2) since r11-5002-ge3b3b59683c1e7d3

[cvs-commit at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100590

--- Comment #3 from CVS Commits <cvs-commit at gcc dot gnu.org> ---
The master branch has been updated by Jakub Jelinek <jakub@gcc.gnu.org>:

https://gcc.gnu.org/g:c81704b359283bb54696755ead881ab04136da94

commit r12-866-gc81704b359283bb54696755ead881ab04136da94
Author: Jakub Jelinek <jakub@redhat.com>
Date:   Tue May 18 10:26:45 2021 +0200

    regcprop: Avoid DCE of asm goto [PR100590]

    The following testcase ICEs, because copyprop_hardreg_forward_1 decides
    to DCE asm goto with REG_UNUSED notes (because the output is unused and
    asm isn't volatile).  But that DCE just removes the asm goto, leaving
    a bb with two successors and no insn at the end that would allow that.

    The following patch makes sure we drop that way only INSNs and not
    JUMP_INSNs or CALL_INSNs.

    2021-05-18  Jakub Jelinek  <jakub@redhat.com>

            PR rtl-optimization/100590
            * regcprop.c (copyprop_hardreg_forward_1): Only DCE dead sets if
            they are NONJUMP_INSN_P.

            * gcc.dg/pr100590.c: New test.

[Bug rtl-optimization/100590] [11 Regression] ICE: verify_flow_info failed (error: too many outgoing branch edges from bb 2) since r11-5002-ge3b3b59683c1e7d3

[jakub at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100590

Jakub Jelinek <jakub at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
            Summary|[11/12 Regression] ICE:     |[11 Regression] ICE:
                   |verify_flow_info failed     |verify_flow_info failed
                   |(error: too many outgoing   |(error: too many outgoing
                   |branch edges from bb 2)     |branch edges from bb 2)
                   |since                       |since
                   |r11-5002-ge3b3b59683c1e7d3  |r11-5002-ge3b3b59683c1e7d3

--- Comment #4 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
Fixed on the trunk so far.

[Bug rtl-optimization/100590] [11 Regression] ICE: verify_flow_info failed (error: too many outgoing branch edges from bb 2) since r11-5002-ge3b3b59683c1e7d3

[cvs-commit at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100590

--- Comment #5 from CVS Commits <cvs-commit at gcc dot gnu.org> ---
The releases/gcc-11 branch has been updated by Jakub Jelinek
<jakub@gcc.gnu.org>:

https://gcc.gnu.org/g:490ffb47ad10df1793c4894c7c888d7a10576f1a

commit r11-8488-g490ffb47ad10df1793c4894c7c888d7a10576f1a
Author: Jakub Jelinek <jakub@redhat.com>
Date:   Tue May 18 10:26:45 2021 +0200

    regcprop: Avoid DCE of asm goto [PR100590]

    The following testcase ICEs, because copyprop_hardreg_forward_1 decides
    to DCE asm goto with REG_UNUSED notes (because the output is unused and
    asm isn't volatile).  But that DCE just removes the asm goto, leaving
    a bb with two successors and no insn at the end that would allow that.

    The following patch makes sure we drop that way only INSNs and not
    JUMP_INSNs or CALL_INSNs.

    2021-05-18  Jakub Jelinek  <jakub@redhat.com>

            PR rtl-optimization/100590
            * regcprop.c (copyprop_hardreg_forward_1): Only DCE dead sets if
            they are NONJUMP_INSN_P.

            * gcc.dg/pr100590.c: New test.

    (cherry picked from commit c81704b359283bb54696755ead881ab04136da94)

[Bug rtl-optimization/100590] [11 Regression] ICE: verify_flow_info failed (error: too many outgoing branch edges from bb 2) since r11-5002-ge3b3b59683c1e7d3

[jakub at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100590

Jakub Jelinek <jakub at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
         Resolution|---                         |FIXED
             Status|ASSIGNED                    |RESOLVED

--- Comment #6 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
Fixed.