[Bug target/114442] New: ICE: in riscv_sched_variable_issue, at config/riscv/riscv.cc:8421 with -O2 -mtune=xiangshan-nanhu

[Bug target/114442] New: ICE: in riscv_sched_variable_issue, at config/riscv/riscv.cc:8421 with -O2 -mtune=xiangshan-nanhu

[zsojka at seznam dot cz]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=114442

            Bug ID: 114442
           Summary: ICE: in riscv_sched_variable_issue, at
                    config/riscv/riscv.cc:8421 with -O2
                    -mtune=xiangshan-nanhu
           Product: gcc
           Version: 14.0
            Status: UNCONFIRMED
          Keywords: ice-on-valid-code
          Severity: normal
          Priority: P3
         Component: target
          Assignee: unassigned at gcc dot gnu.org
          Reporter: zsojka at seznam dot cz
  Target Milestone: ---
              Host: x86_64-pc-linux-gnu
            Target: riscv64-unknown-linux-gnu

Created attachment 57787
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=57787&action=edit
reduced testcase

Compiler output:
$ riscv64-unknown-linux-gnu-gcc -O2 -mtune=xiangshan-nanhu testcase.c 
during RTL pass: sched2
testcase.c: In function 'foo':
testcase.c:1:18: internal compiler error: in riscv_sched_variable_issue, at
config/riscv/riscv.cc:8421
    1 | void foo (void) {}
      |                  ^
0xb84f66 riscv_sched_variable_issue
        /repo/gcc-trunk/gcc/config/riscv/riscv.cc:8421
0xb84f66 riscv_sched_variable_issue
        /repo/gcc-trunk/gcc/config/riscv/riscv.cc:8401
0x2a4205e schedule_block(basic_block_def**, void*)
        /repo/gcc-trunk/gcc/haifa-sched.cc:6912
0x16b4f74 schedule_region
        /repo/gcc-trunk/gcc/sched-rgn.cc:3203
0x16b4f74 schedule_insns()
        /repo/gcc-trunk/gcc/sched-rgn.cc:3525
0x16b540d schedule_insns()
        /repo/gcc-trunk/gcc/sched-rgn.cc:3511
0x16b540d rest_of_handle_sched2
        /repo/gcc-trunk/gcc/sched-rgn.cc:3749
0x16b540d execute
        /repo/gcc-trunk/gcc/sched-rgn.cc:3888
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.

$ riscv64-unknown-linux-gnu-gcc -v
Using built-in specs.
COLLECT_GCC=/repo/gcc-trunk/binary-latest-riscv64/bin/riscv64-unknown-linux-gnu-gcc
COLLECT_LTO_WRAPPER=/repo/gcc-trunk/binary-trunk-r14-9644-20240323110757-g543585046d1-checking-yes-rtl-df-extra-riscv64/bin/../libexec/gcc/riscv64-unknown-linux-gnu/14.0.1/lto-wrapper
Target: riscv64-unknown-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 --with-isa-spec=2.2
--with-sysroot=/usr/riscv64-unknown-linux-gnu --build=x86_64-pc-linux-gnu
--host=x86_64-pc-linux-gnu --target=riscv64-unknown-linux-gnu
--with-ld=/usr/bin/riscv64-unknown-linux-gnu-ld
--with-as=/usr/bin/riscv64-unknown-linux-gnu-as --disable-multilib
--enable-libsanitizer --disable-libstdcxx-pch
--prefix=/repo/gcc-trunk//binary-trunk-r14-9644-20240323110757-g543585046d1-checking-yes-rtl-df-extra-riscv64
Thread model: posix
Supported LTO compression algorithms: zlib zstd
gcc version 14.0.1 20240323 (experimental) (GCC)

[Bug target/114442] ICE: in riscv_sched_variable_issue, at config/riscv/riscv.cc:8421 with -O2 -mtune=xiangshan-nanhu

[law at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=114442

Jeffrey A. Law <law at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
   Last reconfirmed|                            |2024-06-16
     Ever confirmed|0                           |1
                 CC|                            |law at gcc dot gnu.org

--- Comment #1 from Jeffrey A. Law <law at gcc dot gnu.org> ---
Yes, the xiangshan-nanhu scheduler model needs some serious work.  The generic
RISC-V code will trigger an ICE if there's an insn in the stream that does not
map to a functional unit in the uarch's scheduler description.

I've asked the submitter of the xiangshan-nanhu port to fix this, but haven't
heard from them since immediately after the request.  Given the lack of
response we should probably seriously consider disabling its scheduler
description until such time as it's been updated.