[Bug rtl-optimization/98793] New: [11 Regression] wrong code with --param=max-jump-thread-duplication-stmts=4

[Bug rtl-optimization/98793] New: [11 Regression] wrong code with --param=max-jump-thread-duplication-stmts=4

[zsojka at seznam dot cz]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=98793

            Bug ID: 98793
           Summary: [11 Regression] wrong code with
                    --param=max-jump-thread-duplication-stmts=4
           Product: gcc
           Version: 11.0
            Status: UNCONFIRMED
          Keywords: wrong-code
          Severity: normal
          Priority: P3
         Component: rtl-optimization
          Assignee: unassigned at gcc dot gnu.org
          Reporter: zsojka at seznam dot cz
  Target Milestone: ---
              Host: x86_64-pc-linux-gnu
            Target: x86_64-pc-linux-gnu

Created attachment 50033
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=50033&action=edit
reduced testcase

Output:
$ x86_64-pc-linux-gnu-gcc -O2 --param=max-jump-thread-duplication-stmts=3
testcase.c -Wno-psabi && ./a.out
$ x86_64-pc-linux-gnu-gcc -O2 --param=max-jump-thread-duplication-stmts=4
testcase.c -Wno-psabi && ./a.out  
Aborted

$ x86_64-pc-linux-gnu-gcc -v
Using built-in specs.
COLLECT_GCC=/repo/gcc-trunk/binary-latest-amd64/bin/x86_64-pc-linux-gnu-gcc
COLLECT_LTO_WRAPPER=/repo/gcc-trunk/binary-trunk-r11-6849-20210122123514-gee78c20e74d-checking-yes-rtl-df-extra-amd64/bin/../libexec/gcc/x86_64-pc-linux-gnu/11.0.0/lto-wrapper
Target: x86_64-pc-linux-gnu
Configured with: /repo/gcc-trunk//configure --enable-languages=c,c++
--enable-valgrind-annotations --disable-nls --enable-checking=yes,rtl,df,extra
--with-cloog --with-ppl --with-isl --build=x86_64-pc-linux-gnu
--host=x86_64-pc-linux-gnu --target=x86_64-pc-linux-gnu
--with-ld=/usr/bin/x86_64-pc-linux-gnu-ld
--with-as=/usr/bin/x86_64-pc-linux-gnu-as --disable-libstdcxx-pch
--prefix=/repo/gcc-trunk//binary-trunk-r11-6849-20210122123514-gee78c20e74d-checking-yes-rtl-df-extra-amd64
Thread model: posix
Supported LTO compression algorithms: zlib zstd
gcc version 11.0.0 20210122 (experimental) (GCC) 

I am unable to further reduce the testcase. I have several similar testcases,
all seem to be related to higher values of
--param=max-jump-thread-duplication-stmts=

[Bug tree-optimization/98793] [11 Regression] wrong code with --param=max-jump-thread-duplication-stmts=4

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=98793

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
          Component|rtl-optimization            |tree-optimization
             Status|UNCONFIRMED                 |NEW
   Last reconfirmed|                            |2021-01-22
   Target Milestone|---                         |11.0
     Ever confirmed|0                           |1

--- Comment #1 from Richard Biener <rguenth at gcc dot gnu.org> ---
Confirmed.

[Bug tree-optimization/98793] [11 Regression] wrong code with --param=max-jump-thread-duplication-stmts=4

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=98793

--- Comment #2 from Richard Biener <rguenth at gcc dot gnu.org> ---
Looks like an interaction between threading and vector lowering, with
-mavx512bw it works (using SDE).

[Bug tree-optimization/98793] [11 Regression] wrong code with --param=max-jump-thread-duplication-stmts=4 since r11-6468-g01da03c915f086fb

[marxin at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=98793

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
            Summary|[11 Regression] wrong code  |[11 Regression] wrong code
                   |with                        |with
                   |--param=max-jump-thread-dup |--param=max-jump-thread-dup
                   |lication-stmts=4            |lication-stmts=4 since
                   |                            |r11-6468-g01da03c915f086fb
                 CC|                            |marxin at gcc dot gnu.org
      Known to work|                            |10.2.0

--- Comment #3 from Martin Liška <marxin at gcc dot gnu.org> ---
Started with r11-6468-g01da03c915f086fb.

[Bug tree-optimization/98793] [11 Regression] wrong code with --param=max-jump-thread-duplication-stmts=4 since r11-6468-g01da03c915f086fb

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=98793

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Assignee|unassigned at gcc dot gnu.org      |rguenth at gcc dot gnu.org
             Status|NEW                         |ASSIGNED
      Known to fail|11.0                        |

--- Comment #4 from Richard Biener <rguenth at gcc dot gnu.org> ---
Mine.  I have a fix, but there's a complication in that if we ever manage to
get boolean vectors for 'generic' vectors (the vectorizer using sth like 'long'
to hold a v8qi) then things will break.

[Bug tree-optimization/98793] [11 Regression] wrong code with --param=max-jump-thread-duplication-stmts=4 since r11-6468-g01da03c915f086fb

[cvs-commit at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=98793

--- Comment #5 from CVS Commits <cvs-commit at gcc dot gnu.org> ---
The master branch has been updated by Richard Biener <rguenth@gcc.gnu.org>:

https://gcc.gnu.org/g:4be156d6bef317b8704052f11431457a577ed564

commit r11-6859-g4be156d6bef317b8704052f11431457a577ed564
Author: Richard Biener <rguenther@suse.de>
Date:   Fri Jan 22 14:32:39 2021 +0100

    middle-end/98793 - properly handle BLKmode vectors in vector_element_bits

    The previous change made AVX512 mask vectors correct but disregarded
    the possibility of generic (BLKmode) boolean vectors which are exposed
    by the frontends already.

    2021-01-22  Richard Biener  <rguenther@suse.de>

            PR middle-end/98793
            * tree.c (vector_element_bits): Key single-bit bool vector on
            integer mode rather than not vector mode.

            * gcc.dg/pr98793.c: New testcase.

[Bug tree-optimization/98793] [11 Regression] wrong code with --param=max-jump-thread-duplication-stmts=4 since r11-6468-g01da03c915f086fb

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=98793

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

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

--- Comment #6 from Richard Biener <rguenth at gcc dot gnu.org> ---
Fixed.