[Bug target/112852] New: [14 Regression] RISCV ICE: vsetvl pass: in partial_subreg_p, at rtl.h:3187 on rv64gcv_zvl512b

[Bug target/112852] New: [14 Regression] RISCV ICE: vsetvl pass: in partial_subreg_p, at rtl.h:3187 on rv64gcv_zvl512b

[patrick at rivosinc dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=112852

            Bug ID: 112852
           Summary: [14 Regression] RISCV ICE: vsetvl pass: in
                    partial_subreg_p, at rtl.h:3187 on rv64gcv_zvl512b
           Product: gcc
           Version: 14.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: target
          Assignee: unassigned at gcc dot gnu.org
          Reporter: patrick at rivosinc dot com
  Target Milestone: ---

Created attachment 56801
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=56801&action=edit
-freport-bug output

Only seen on rv64gcv_zvl512b:
pr112598

FAIL: gcc.c-torture/compile/20090907-1.c   -O3 -fomit-frame-pointer
-funroll-loops -fpeel-loops -ftracer -finline-functions  (internal compiler
error: in partial_subreg_p, at rtl.h:3187)

Command:
> /scratch/tc-testing/tc-dec-4-trunk/build-rv64gcv/bin/riscv64-unknown-linux-gnu-gcc -march=rv64gcv_zvl512b -mabi=lp64d -O3 20090907-1.c -ftracer -funroll-loops -freport-bug
during RTL pass: vsetvl
20090907-1.c: In function 'metronomefb_probe':
20090907-1.c:84:1: internal compiler error: in partial_subreg_p, at rtl.h:3187
   84 | }
      | ^
0xb3a42b partial_subreg_p(machine_mode, machine_mode)
        ../../../gcc/gcc/rtl.h:3187
0xb3a42b partial_subreg_p(machine_mode, machine_mode)
        ../../../gcc/gcc/rtl.h:3181
0xb3a42b
rtl_ssa::function_info::record_use(rtl_ssa::function_info::build_info&,
rtl_ssa::insn_info*, rtx_obj_reference)
        ../../../gcc/gcc/rtl-ssa/insns.cc:524
0x23ee521
rtl_ssa::function_info::add_insn_to_block(rtl_ssa::function_info::build_info&,
rtx_insn*)
        ../../../gcc/gcc/rtl-ssa/insns.cc:662
0x2a0876d
rtl_ssa::function_info::add_block_contents(rtl_ssa::function_info::build_info&)
        ../../../gcc/gcc/rtl-ssa/blocks.cc:948
0x2a08e8a
rtl_ssa::function_info::start_block(rtl_ssa::function_info::build_info&,
rtl_ssa::bb_info*)
        ../../../gcc/gcc/rtl-ssa/blocks.cc:1064
0x2a08f1c
rtl_ssa::function_info::bb_walker::before_dom_children(basic_block_def*)
        ../../../gcc/gcc/rtl-ssa/blocks.cc:117
0x225c207 dom_walker::walk(basic_block_def*)
        ../../../gcc/gcc/domwalk.cc:311
0x2a0a5c9 rtl_ssa::function_info::process_all_blocks()
        ../../../gcc/gcc/rtl-ssa/blocks.cc:1281
0x23ebb68 rtl_ssa::function_info::function_info(function*)
        ../../../gcc/gcc/rtl-ssa/functions.cc:50
0x1734d12 pre_vsetvl::pre_vsetvl()
        ../../../gcc/gcc/config/riscv/riscv-vsetvl.cc:2218
0x1733527 pass_vsetvl::lazy_vsetvl()
        ../../../gcc/gcc/config/riscv/riscv-vsetvl.cc:3454
0x173391f pass_vsetvl::execute(function*)
        ../../../gcc/gcc/config/riscv/riscv-vsetvl.cc:3518
0x173391f pass_vsetvl::execute(function*)
        ../../../gcc/gcc/config/riscv/riscv-vsetvl.cc:3501
Please submit a full bug report, with preprocessed source.
Please include the complete backtrace with any bug report.
See <https://gcc.gnu.org/bugs/> for instructions.
Preprocessed source stored into /scratch/tmp/ccO9eL35.out file, please attach
this to your bugreport.

Testcase:
https://gcc.gnu.org/git/?p=gcc.git;a=blob;f=gcc/testsuite/gcc.c-torture/compile/20090907-1.c;h=12cf1185b93b973ce21e24039c00d9b7be855894;hb=HEAD

Godbolt:
https://godbolt.org/z/chdK4TnKx

creduced testcase:
char a;
char *b;
int c;
void d() {
  int e = 0, f = 0;
  for (; f <= a; f++)
    if (b[f])
      e = f - 1;
  c = e;
}

[Bug target/112852] [14 Regression] RISCV ICE: vsetvl pass: in partial_subreg_p, at rtl.h:3187 on rv64gcv_zvl512b

[patrick at rivosinc dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=112852

Patrick O'Neill <patrick at rivosinc dot com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Target|                            |riscv
           Keywords|                            |ice-on-valid-code
           See Also|                            |https://gcc.gnu.org/bugzill
                   |                            |a/show_bug.cgi?id=112851
                 CC|                            |juzhe.zhong at rivai dot ai,
                   |                            |patrick at rivosinc dot com,
                   |                            |rdapp at gcc dot gnu.org

--- Comment #1 from Patrick O'Neill <patrick at rivosinc dot com> ---
Looks related to pr112851.

[Bug target/112852] [14 Regression] RISCV ICE: vsetvl pass: in partial_subreg_p, at rtl.h:3187 on rv64gcv_zvl512b

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=112852

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|---                         |14.0

[Bug target/112852] [14 Regression] RISCV ICE: vsetvl pass: in partial_subreg_p, at rtl.h:3187 on rv64gcv_zvl512b

[cvs-commit at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=112852

--- Comment #2 from GCC 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:2e7abd09621a4401d44f4513adf126bce4b4828b

commit r14-6197-g2e7abd09621a4401d44f4513adf126bce4b4828b
Author: Juzhe-Zhong <juzhe.zhong@rivai.ai>
Date:   Tue Dec 5 20:57:27 2023 +0800

    RISC-V: Block VLSmodes according to TARGET_MAX_LMUL and
BITS_PER_RISCV_VECTOR

    This patch fixes ICE mentioned on PR112851 and PR112852.
    Actually these ICEs happens many times in full coverage testing.

    The ICE happens on:

    bug.c:84:1: internal compiler error: in partial_subreg_p, at rtl.h:3187
       84 | }
          | ^
    0x11a7271 partial_subreg_p(machine_mode, machine_mode)
            ../../../../gcc/gcc/rtl.h:3187

    gcc_checking_assert (ordered_p (outer_prec, inner_prec));

    outer_prec is the PRECISION of RVVM1SImode
    inner_prec is the PRECISION of V64SImode

    when it is zvl512b.

    outer_prec is VLA mode with size (512, 512)
    inner_prec is VLS mode with size (2048, 0)

    Their precision/size relationship is not certain.
    So block VLSmodes according to TARGET_MAX_LMUL and BITS_PER_RISCV_VECTOR,
then we never reaches
    the situation that comparing the precision/size between VLA size and VLS
size that size > coeffs[0] of VLA mode.

    Note this patch cause following regression:

    FAIL: gcc.target/riscv/rvv/autovec/pr111751.c -O3 -ftree-vectorize 
scan-assembler-not vset
    FAIL: gcc.target/riscv/rvv/autovec/pr111751.c -O3 -ftree-vectorize 
scan-assembler-times li\\s+[a-x0-9]+,0\\s+ret 2

    FAIL: gcc.target/riscv/rvv/base/cpymem-1.c check-function-bodies f3
    FAIL: gcc.target/riscv/rvv/base/cpymem-2.c check-function-bodies f2
    FAIL: gcc.target/riscv/rvv/base/cpymem-2.c check-function-bodies f3

    1. cpymem check FAIL should be fixed on the testcase since the test is
fragile which should be robostified.

    2. pr111751.c is Vector cost model issue, and I will fix it in the
following patch.

    For now, we should land this patch first (highest-priority) since it is
fixing ICE.

            PR target/112851
            PR target/112852

    gcc/ChangeLog:

            * config/riscv/riscv-v.cc (vls_mode_valid_p): Block VLSmodes
according
            TARGET_MAX_LMUL and BITS_PER_RISCV_VECTOR.

    gcc/testsuite/ChangeLog:

            * gcc.target/riscv/rvv/autovec/vls/consecutive-1.c: Add LMUL = 8
option.
            * gcc.target/riscv/rvv/autovec/vls/consecutive-2.c: Ditto.
            * gcc.target/riscv/rvv/autovec/vls/mod-1.c: Ditto.
            * gcc.target/riscv/rvv/autovec/vls/mov-1.c: Ditto.
            * gcc.target/riscv/rvv/autovec/vls/mov-10.c: Ditto.
            * gcc.target/riscv/rvv/autovec/vls/mov-11.c: Ditto.
            * gcc.target/riscv/rvv/autovec/vls/mov-12.c: Ditto.
            * gcc.target/riscv/rvv/autovec/vls/mov-13.c: Ditto.
            * gcc.target/riscv/rvv/autovec/vls/mov-14.c: Ditto.
            * gcc.target/riscv/rvv/autovec/vls/mov-15.c: Ditto.
            * gcc.target/riscv/rvv/autovec/vls/mov-16.c: Ditto.
            * gcc.target/riscv/rvv/autovec/vls/mov-17.c: Ditto.
            * gcc.target/riscv/rvv/autovec/vls/mov-3.c: Ditto.
            * gcc.target/riscv/rvv/autovec/vls/mov-5.c: Ditto.
            * gcc.target/riscv/rvv/autovec/vls/mov-7.c: Ditto.
            * gcc.target/riscv/rvv/autovec/vls/mov-8.c: Ditto.
            * gcc.target/riscv/rvv/autovec/vls/mov-9.c: Ditto.
            * gcc.target/riscv/rvv/autovec/vls/spill-1.c: Ditto.
            * gcc.target/riscv/rvv/autovec/vls/spill-2.c: Ditto.
            * gcc.target/riscv/rvv/autovec/vls/spill-3.c: Ditto.
            * gcc.target/riscv/rvv/autovec/vls/spill-5.c: Ditto.
            * gcc.target/riscv/rvv/autovec/vls/spill-6.c: Ditto.
            * gcc.target/riscv/rvv/autovec/zve32f-1.c: Adapt test.
            * gcc.target/riscv/rvv/autovec/pr112851.c: New test.
            * gcc.target/riscv/rvv/autovec/pr112852.c: New test.

[Bug target/112852] [14 Regression] RISCV ICE: vsetvl pass: in partial_subreg_p, at rtl.h:3187 on rv64gcv_zvl512b

[patrick at rivosinc dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=112852

Patrick O'Neill <patrick at rivosinc dot com> changed:

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

--- Comment #3 from Patrick O'Neill <patrick at rivosinc dot com> ---
Fixed. Thank you!