[Bug rtl-optimization/99554] New: SVE: ICE (segfault) in recog.c:extract_asm_operands during expand

[Bug rtl-optimization/99554] New: SVE: ICE (segfault) in recog.c:extract_asm_operands during expand

[acoplan at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=99554

            Bug ID: 99554
           Summary: SVE: ICE (segfault) in recog.c:extract_asm_operands
                    during expand
           Product: gcc
           Version: 11.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: rtl-optimization
          Assignee: unassigned at gcc dot gnu.org
          Reporter: acoplan at gcc dot gnu.org
  Target Milestone: ---

The following fails:

$ cat test.cc
int a[21][256];
void b() {
  for (long c; c; ++c)
    for (long d = 0; d < 16; ++d)
      for (long e = 0; e < 16; ++e)
        a[c][d * 16 + e] = 8;
}

$ aarch64-linux-gnu-gcc -c test.cc -O3 -march=armv8.2-a+sve
-fvect-cost-model=unlimited -ftrapv
during RTL pass: expand
test.cc: In function ‘void b()’:
test.cc:7:1: internal compiler error: Segmentation fault
    7 | }
      | ^
0x10acb6d crash_signal
        /home/alecop01/toolchain/src/gcc/gcc/toplev.c:327
0xff83c2 extract_asm_operands(rtx_def*)
        /home/alecop01/toolchain/src/gcc/gcc/recog.c:1901
0xeb3c00 mark_jump_label(rtx_def*, rtx_insn*, int)
        /home/alecop01/toolchain/src/gcc/gcc/jump.c:1080
0xeb4431 mark_all_labels
        /home/alecop01/toolchain/src/gcc/gcc/jump.c:332
0xeb4431 rebuild_jump_labels_1
        /home/alecop01/toolchain/src/gcc/gcc/jump.c:74
0xeb44ed rebuild_jump_labels(rtx_insn*)
        /home/alecop01/toolchain/src/gcc/gcc/jump.c:98
0xb6c8b1 execute
        /home/alecop01/toolchain/src/gcc/gcc/cfgexpand.c:6779
Please submit a full bug report,
with preprocessed source if appropriate.
Please include the complete backtrace with any bug report.
See <https://gcc.gnu.org/bugs/> for instructions.

[Bug rtl-optimization/99554] [10/11 Regression] SVE: ICE (segfault) in recog.c:extract_asm_operands during expand

[acoplan at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=99554

Alex Coplan <acoplan at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
            Summary|SVE: ICE (segfault) in      |[10/11 Regression] SVE: ICE
                   |recog.c:extract_asm_operand |(segfault) in
                   |s during expand             |recog.c:extract_asm_operand
                   |                            |s during expand

--- Comment #1 from Alex Coplan <acoplan at gcc dot gnu.org> ---
GCC 10 ICEs as well.

[Bug rtl-optimization/99554] [10/11 Regression] SVE: ICE (segfault) in recog.c:extract_asm_operands during expand

[acoplan at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=99554

Alex Coplan <acoplan at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
      Known to fail|                            |10.2.1
      Known to work|                            |9.2.1
   Target Milestone|---                         |10.3

[Bug rtl-optimization/99554] [10/11 Regression] SVE: ICE (segfault) in recog.c:extract_asm_operands during expand

[jakub at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=99554

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |jakub at gcc dot gnu.org
     Ever confirmed|0                           |1
   Last reconfirmed|                            |2021-03-19
             Status|UNCONFIRMED                 |NEW

--- Comment #2 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
Started with r10-2554-g7d8bdfa7e409821c50f6d8a7b557bd7dc760c4ce

[Bug rtl-optimization/99554] [10/11 Regression] SVE: ICE (segfault) in recog.c:extract_asm_operands during expand

[jakub at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=99554

--- Comment #3 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
The ICE is because of invalid RTL emitted, SET with NULL SET_SRC.
This is emitted by aarch64_add_offset, which is called on
DImode pseudo dest, const0_rtx src and offset {252,252}.
So, factor 252, constant 0.
The problem is that expand_mult fails (returns NULL) when called with
(DImode, DImode pseudo REG, (const_int 63), NULL, false, true).
And that is because of flag_trapv.

IMHO either aarch64_add_offset needs to temporarily disable flag_trapv around
that expand_mult call, or it can't pass true as last argument when flag_trapv
- trapv multiplication handling isn't supported inline.

[Bug rtl-optimization/99554] [10/11 Regression] SVE: ICE (segfault) in recog.c:extract_asm_operands during expand

[acoplan at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=99554

Alex Coplan <acoplan at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
         Resolution|---                         |DUPLICATE
             Status|NEW                         |RESOLVED

--- Comment #4 from Alex Coplan <acoplan at gcc dot gnu.org> ---
Ah, this is a really a dup then (same underlying problem).

*** This bug has been marked as a duplicate of bug 99540 ***