[Bug middle-end/111295] New: RISC-V vector ICE in vsetvl pass

[Bug middle-end/111295] New: RISC-V vector ICE in vsetvl pass

[jeremy.bennett at embecosm dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=111295

            Bug ID: 111295
           Summary: RISC-V vector ICE in vsetvl pass
           Product: gcc
           Version: 14.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: middle-end
          Assignee: unassigned at gcc dot gnu.org
          Reporter: jeremy.bennett at embecosm dot com
  Target Milestone: ---

Created attachment 55843
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=55843&action=edit
Test case

The following issue was identified while attempting to compile SPEC CPU 2017
600.perlbench_s benchmark.

Reproducer (test.c):

int a, b, c, e, f, g, h, i, j, k;
long l;
int q ()
{
  int r ();
  char *o, *d;
  _Bool p = f;
  while (g)
    {
      int m, n;
      for (; m <= n; m++)
        *d++ = m;
      k = 1;
      if (e)
        break;
      switch (*o)
        {
        case 'N':
          o++;
          if (c)
            if (h)
              while (i)
                {
                  s (-l, ~0);
                  t (j);
                  d = d + (a & 10000000 ? u (r, 2) : b);
                }
        }
      if (*o)
        p ? s () : 0;
    }
}

This is compiled with:

riscv64-unknown-linux-gnu-gcc -march=rv64gcv -mabi=lp64d -c \
    -Wno-implicit-function-declaration -Ofast \
    -ftree-vectorize --param=riscv-autovec-preference=scalable test.c

The output is:

during RTL pass: vsetvl
test.c: In function 'q':
test.c:32:1: internal compiler error: Segmentation fault
   32 | }
      | ^
0x10db7d3 crash_signal
        /home/jeremy/gittrees/mustang/gcc/gcc/toplev.cc:314
0x7fc85743c4af ???
        ./signal/../sysdeps/unix/sysv/linux/x86_64/libc_sigaction.c:0
0x1548f8a riscv_vector::vector_insn_info::get_avl_reg_rtx() const
        /home/jeremy/gittrees/mustang/gcc/gcc/config/riscv/riscv-vsetvl.h:339
0x1548f8a insert_vsetvl
        /home/jeremy/gittrees/mustang/gcc/gcc/config/riscv/riscv-vsetvl.cc:750
0x1549a5d pass_vsetvl::commit_vsetvls()
        /home/jeremy/gittrees/mustang/gcc/gcc/config/riscv/riscv-vsetvl.cc:3642
0x1549d11 pass_vsetvl::pre_vsetvl()
        /home/jeremy/gittrees/mustang/gcc/gcc/config/riscv/riscv-vsetvl.cc:3755
0x154b988 pass_vsetvl::lazy_vsetvl()
        /home/jeremy/gittrees/mustang/gcc/gcc/config/riscv/riscv-vsetvl.cc:4442
0x154ba91 pass_vsetvl::execute(function*)
        /home/jeremy/gittrees/mustang/gcc/gcc/config/riscv/riscv-vsetvl.cc:4477
0x154ba91 pass_vsetvl::execute(function*)
        /home/jeremy/gittrees/mustang/gcc/gcc/config/riscv/riscv-vsetvl.cc:4458
Please submit a full bug report, with preprocessed source (by using
-freport-bug).
Please include the complete backtrace with any bug report.
See <https://gcc.gnu.org/bugs/> for instructions.

System information
------------------

Using built-in specs.
COLLECT_GCC=riscv64-unknown-linux-gnu-gcc
COLLECT_LTO_WRAPPER=/home/jeremy/gittrees/mustang/install/libexec/gcc/riscv64-unknown-linux-gnu/14.0.0/lto-wrapper
Target: riscv64-unknown-linux-gnu
Configured with: /home/jeremy/gittrees/mustang/gcc/configure
--target=riscv64-unknown-linux-gnu
--prefix=/home/jeremy/gittrees/mustang/install
--with-sysroot=/home/jeremy/gittrees/mustang/install/sysroot
--with-pkgversion=g8451fbd5687 --with-system-zlib --enable-shared --enable-tls
--enable-languages=c,c++,fortran --disable-libmudflap --disable-libssp
--disable-libquadmath --disable-libsanitizer --disable-nls --disable-bootstrap
--src=/home/jeremy/gittrees/mustang/gcc --enable-multilib --with-abi=lp64d
--with-arch=rv64gc --with-tune= --with-isa-spec=20191213 'CFLAGS_FOR_TARGET=-O2
   -mcmodel=medany' 'CXXFLAGS_FOR_TARGET=-O2    -mcmodel=medany'
Thread model: posix
Supported LTO compression algorithms: zlib
gcc version 14.0.0 20230904 (experimental) (g8451fbd5687)

[Bug target/111295] RISC-V vector ICE in vsetvl pass

[jeremy.bennett at embecosm dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=111295

--- Comment #1 from Jeremy Bennett <jeremy.bennett at embecosm dot com> ---
Further analysis suggests this also causes the following SPEC CPU 2017
benchmarks to fail: 602.gcc_s, 648.exchange2_s, 607.cactuBSSN_s, 621.wrf_s,
627.cam4_s, 628.pop2_s, 638.imagick_s, 649.fotonik3d_s and 654.roms_s

[Bug target/111295] RISC-V vector ICE in vsetvl pass

[juzhe.zhong at rivai dot ai]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=111295

JuzheZhong <juzhe.zhong at rivai dot ai> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |juzhe.zhong at rivai dot ai

--- Comment #2 from JuzheZhong <juzhe.zhong at rivai dot ai> ---
confirm

[Bug target/111295] RISC-V vector ICE in vsetvl pass

[juzhe.zhong at rivai dot ai]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=111295

--- Comment #3 from JuzheZhong <juzhe.zhong at rivai dot ai> ---
This code can not be compiled:

cc1plus: warning: command-line option '-Wno-implicit-function-declaration' is
valid for C/ObjC but not for C++
bug.C: In function 'int q()':
bug.C:6:9: warning: empty parentheses were disambiguated as a function
declaration [-Wvexing-parse]
    6 |   int r ();
      |         ^~
bug.C:6:9: note: remove parentheses to default-initialize a variable
    6 |   int r ();
      |         ^~
      |         --
bug.C:25:19: error: 's' was not declared in this scope
   25 |                   s (-l, ~0);
      |                   ^
bug.C:26:19: error: 't' was not declared in this scope
   26 |                   t (j);
      |                   ^
bug.C:27:43: error: 'u' was not declared in this scope
   27 |                   d = d + (a & 10000000 ? u (r, 2) : b);
      |                                           ^
bug.C:31:13: error: 's' was not declared in this scope
   31 |         p ? s () : 0;
      |             ^
bug.C:33:1: warning: no return statement in function returning non-void
[-Wreturn-type]
   33 | }

[Bug target/111295] RISC-V vector ICE in vsetvl pass

[jeremy.bennett at embecosm dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=111295

--- Comment #4 from Jeremy Bennett <jeremy.bennett at embecosm dot com> ---
@JuzheZhong  - it's a C test case, not C++.  Look like you are trying to
compile it as C++.

[Bug target/111295] RISC-V vector ICE in vsetvl pass

[juzhe.zhong at rivai dot ai]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=111295

--- Comment #5 from JuzheZhong <juzhe.zhong at rivai dot ai> ---
I see. A candidate patch to fix this issue:
https://gcc.gnu.org/pipermail/gcc-patches/2023-September/629456.html

[Bug target/111295] RISC-V vector ICE in vsetvl pass

[cvs-commit at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=111295

--- Comment #6 from CVS Commits <cvs-commit at gcc dot gnu.org> ---
The master branch has been updated by Pan Li <panli@gcc.gnu.org>:

https://gcc.gnu.org/g:1b4c70d4271a00514ae20970d483c3b78d9d66ef

commit r14-3743-g1b4c70d4271a00514ae20970d483c3b78d9d66ef
Author: Juzhe-Zhong <juzhe.zhong@rivai.ai>
Date:   Wed Sep 6 20:47:24 2023 +0800

    RISC-V: Fix VSETVL PASS AVL/VL fetch bug[111295]

    Fix bugzilla: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=111295

    gcc/ChangeLog:

            PR target/111295
            * config/riscv/riscv-vsetvl.cc (insert_vsetvl): Bug fix.

    gcc/testsuite/ChangeLog:

            PR target/111295
            * gcc.target/riscv/rvv/autovec/pr111295.c: New test.

[Bug target/111295] RISC-V vector ICE in vsetvl pass

[jeremy.bennett at embecosm dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=111295

Jeremy Bennett <jeremy.bennett at embecosm dot com> changed:

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

--- Comment #7 from Jeremy Bennett <jeremy.bennett at embecosm dot com> ---
I can confirm this patch resolves the issue.