[Bug target/99249] New: SVE: ICE in aarch64_expand_sve_const_vector (during RTL pass: early_remat)

[Bug target/99249] New: SVE: ICE in aarch64_expand_sve_const_vector (during RTL pass: early_remat)

[acoplan at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=99249

            Bug ID: 99249
           Summary: SVE: ICE in aarch64_expand_sve_const_vector (during
                    RTL pass: early_remat)
           Product: gcc
           Version: 11.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: target
          Assignee: unassigned at gcc dot gnu.org
          Reporter: acoplan at gcc dot gnu.org
  Target Milestone: ---

The following fails:

$ cat test.cc
#include <arm_sve.h>
extern char b[];
int x;
void f() {
  while (x) {
    x = svaddv(
        svnot_z(svnot_z(svptrue_pat_b8(SV_VL6),
                        svmov_z(svptrue_pat_b8(SV_VL1),
                                svptrue_pat_b16(SV_VL3))),
                svptrue_pat_b64(SV_VL2)),
        svdup_s32(8193));
    for (int j = x; j; j++)
      b[j] = 0;
  }
}
$ aarch64-linux-gnu-gcc -c -march=armv8.2-a+sve -Os test.cc
during RTL pass: early_remat
test.cc: In function ‘void f()’:
test.cc:15:1: internal compiler error: in aarch64_expand_sve_const_vector, at
config/aarch64/aarch64.c:4956
   15 | }
      | ^
0x14ffb66 aarch64_expand_sve_const_vector
        /home/alecop01/toolchain/src/gcc/gcc/config/aarch64/aarch64.c:4956
0x15019b1 aarch64_expand_mov_immediate(rtx_def*, rtx_def*)
        /home/alecop01/toolchain/src/gcc/gcc/config/aarch64/aarch64.c:5395
0x19afb10 gen_movvnx16qi(rtx_def*, rtx_def*)
        /home/alecop01/toolchain/src/gcc/gcc/config/aarch64/aarch64-sve.md:662
0xcab8e6 rtx_insn* insn_gen_fn::operator()<rtx_def*, rtx_def*>(rtx_def*,
rtx_def*) const
        /home/alecop01/toolchain/src/gcc/gcc/recog.h:407
0xcab8e6 emit_move_insn_1(rtx_def*, rtx_def*)
        /home/alecop01/toolchain/src/gcc/gcc/expr.c:3766
0xcabe37 emit_move_insn(rtx_def*, rtx_def*)
        /home/alecop01/toolchain/src/gcc/gcc/expr.c:3936
0xc7e694 force_reg(machine_mode, rtx_def*)
        /home/alecop01/toolchain/src/gcc/gcc/explow.c:677
0x14ffc4f aarch64_expand_sve_const_vector
        /home/alecop01/toolchain/src/gcc/gcc/config/aarch64/aarch64.c:4964
0x15019b1 aarch64_expand_mov_immediate(rtx_def*, rtx_def*)
        /home/alecop01/toolchain/src/gcc/gcc/config/aarch64/aarch64.c:5395
0x19afb10 gen_movvnx16qi(rtx_def*, rtx_def*)
        /home/alecop01/toolchain/src/gcc/gcc/config/aarch64/aarch64-sve.md:662
0xcab8e6 rtx_insn* insn_gen_fn::operator()<rtx_def*, rtx_def*>(rtx_def*,
rtx_def*) const
        /home/alecop01/toolchain/src/gcc/gcc/recog.h:407
0xcab8e6 emit_move_insn_1(rtx_def*, rtx_def*)
        /home/alecop01/toolchain/src/gcc/gcc/expr.c:3766
0xcabe37 emit_move_insn(rtx_def*, rtx_def*)
        /home/alecop01/toolchain/src/gcc/gcc/expr.c:3936
0xc7e614 copy_to_mode_reg(machine_mode, rtx_def*)
        /home/alecop01/toolchain/src/gcc/gcc/explow.c:653
0xf69b69 maybe_legitimize_operand
        /home/alecop01/toolchain/src/gcc/gcc/optabs.c:7626
0xf69b69 maybe_legitimize_operands(insn_code, unsigned int, unsigned int,
expand_operand*)
        /home/alecop01/toolchain/src/gcc/gcc/optabs.c:7758
0xf69e52 maybe_gen_insn(insn_code, unsigned int, expand_operand*)
        /home/alecop01/toolchain/src/gcc/gcc/optabs.c:7777
0xf6a06e maybe_expand_insn(insn_code, unsigned int, expand_operand*)
        /home/alecop01/toolchain/src/gcc/gcc/optabs.c:7820
0xf69605 expand_insn(insn_code, unsigned int, expand_operand*)
        /home/alecop01/toolchain/src/gcc/gcc/optabs.c:7851
0x14d45d2 aarch64_sve_emit_int_cmp
        /home/alecop01/toolchain/src/gcc/gcc/config/aarch64/aarch64.c:3920
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 target/99249] SVE: ICE in aarch64_expand_sve_const_vector (during RTL pass: early_remat)

[ktkachov at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=99249

ktkachov at gcc dot gnu.org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
      Known to fail|                            |10.2.1
             Status|UNCONFIRMED                 |NEW
     Ever confirmed|0                           |1
                 CC|                            |ktkachov at gcc dot gnu.org
   Target Milestone|---                         |10.3
   Last reconfirmed|                            |2021-02-24

--- Comment #1 from ktkachov at gcc dot gnu.org ---
Confirmed on the 10 branch as well.

[Bug target/99249] SVE: ICE in aarch64_expand_sve_const_vector (during RTL pass: early_remat)

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=99249

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|10.3                        |10.4

--- Comment #2 from Richard Biener <rguenth at gcc dot gnu.org> ---
GCC 10.3 is being released, retargeting bugs to GCC 10.4.

[Bug target/99249] SVE: ICE in aarch64_expand_sve_const_vector (during RTL pass: early_remat)

[rsandifo at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=99249

rsandifo at gcc dot gnu.org <rsandifo at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |rsandifo at gcc dot gnu.org
             Status|NEW                         |ASSIGNED

--- Comment #3 from rsandifo at gcc dot gnu.org <rsandifo at gcc dot gnu.org> ---
Mine.

[Bug target/99249] SVE: ICE in aarch64_expand_sve_const_vector (during RTL pass: early_remat)

[rsandifo at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=99249

rsandifo at gcc dot gnu.org <rsandifo at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Assignee|unassigned at gcc dot gnu.org      |rsandifo at gcc dot gnu.org

--- Comment #4 from rsandifo at gcc dot gnu.org <rsandifo at gcc dot gnu.org> ---
Fixed by
https://gcc.gnu.org/git/gitweb.cgi?p=gcc.git;h=a065e0bb092a010664777394530ab1a52bb5293b,
but I typoed the PR number.

[Bug target/99249] [8/9/10 Backport] SVE: ICE in aarch64_expand_sve_const_vector (during RTL pass: early_remat)

[cvs-commit at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=99249

--- Comment #5 from CVS Commits <cvs-commit at gcc dot gnu.org> ---
The releases/gcc-10 branch has been updated by Richard Sandiford
<rsandifo@gcc.gnu.org>:

https://gcc.gnu.org/g:690aa217cf2882e58a0572171a3dd8e346f616cf

commit r10-9754-g690aa217cf2882e58a0572171a3dd8e346f616cf
Author: Richard Sandiford <richard.sandiford@arm.com>
Date:   Fri Apr 23 10:09:42 2021 +0100

    aarch64: Handle more SVE vector constants [PR99246]

    PR99246 is about a case in which we failed to handle a CONST_VECTOR
    with NELTS_PER_PATTERN==2, i.e. a vector with a âforegroundâ sequence
    of N vectors followed by a repeating âbackgroundâ sequence of N
vectors.

    At the moment, it's difficult to produce these vectors directly,
    but I'm hoping that for GCC 12 we'll do more folding, which will
    in turn make this easier to test and easier to optimise.  Until then,
    the patch simply relies on the testcase in the PR.

    gcc/
            PR target/99249
            * config/aarch64/aarch64.c (aarch64_expand_sve_const_vector_sel):
            New function.
            (aarch64_expand_sve_const_vector): Use it for nelts_per_pattern==2.

    gcc/testsuite/
            PR target/99249
            * gcc.target/aarch64/sve/acle/general/pr99246.c: New test.

    (cherry picked from commit a065e0bb092a010664777394530ab1a52bb5293b)

[Bug target/99249] SVE: ICE in aarch64_expand_sve_const_vector (during RTL pass: early_remat)

[rsandifo at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=99249

rsandifo at gcc dot gnu.org <rsandifo at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
         Resolution|---                         |FIXED
             Status|ASSIGNED                    |RESOLVED
            Summary|[8/9 Backport] SVE: ICE in  |SVE: ICE in
                   |aarch64_expand_sve_const_ve |aarch64_expand_sve_const_ve
                   |ctor (during RTL pass:      |ctor (during RTL pass:
                   |early_remat)                |early_remat)

--- Comment #6 from rsandifo at gcc dot gnu.org <rsandifo at gcc dot gnu.org> ---
I was going to backport this further than GCC 10, but it turns
out that the code changed too much in the GCC 9->GCC 10 timeframe
for it to apply cleanly.  I'm also not aware of any way of triggering
the bug before GCC 10.