Bug 111590 - RISC-V: Multiple ICE in gfortran regression with 'V' Extension enabled
Summary: RISC-V: Multiple ICE in gfortran regression with 'V' Extension enabled
Status: RESOLVED FIXED
Alias: None
Product: gcc
Classification: Unclassified
Component: target (show other bugs)
Version: 14.0
: P3 normal
Target Milestone: ---
Assignee: Not yet assigned to anyone
URL:
Keywords:
Depends on:
Blocks:
 
Reported: 2023-09-25 11:49 UTC by JuzheZhong
Modified: 2023-09-27 08:29 UTC (History)
0 users

See Also:
Host:
Target: riscv
Build:
Known to work:
Known to fail:
Last reconfirmed:


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Description JuzheZhong 2023-09-25 11:49:24 UTC
FAIL: gfortran.dg/assumed_rank_24.f90   -O2  (internal compiler error: in smallest_mode_for_size, at stor-layout.cc:356)
FAIL: gfortran.dg/assumed_rank_24.f90   -O2  (test for excess errors)
FAIL: gfortran.dg/assumed_rank_24.f90   -O3 -fomit-frame-pointer -funroll-loops -fpeel-loops -ftracer -finline-functions  (internal compiler error: in smallest_mode_for_size, at stor-layout.cc:356)
FAIL: gfortran.dg/assumed_rank_24.f90   -O3 -fomit-frame-pointer -funroll-loops -fpeel-loops -ftracer -finline-functions  (test for excess errors)
FAIL: gfortran.dg/assumed_rank_24.f90   -O3 -g  (internal compiler error: in smallest_mode_for_size, at stor-layout.cc:356)
FAIL: gfortran.dg/assumed_rank_24.f90   -O3 -g  (test for excess errors)
FAIL: gfortran.dg/class_to_type_1.f03   -O2  (internal compiler error: in smallest_mode_for_size, at stor-layout.cc:356)
FAIL: gfortran.dg/class_to_type_1.f03   -O2  (test for excess errors)
FAIL: gfortran.dg/class_to_type_1.f03   -O3 -fomit-frame-pointer -funroll-loops -fpeel-loops -ftracer -finline-functions  (internal compiler error: in smallest_mode_for_size, at stor-layout.cc:356)
FAIL: gfortran.dg/class_to_type_1.f03   -O3 -fomit-frame-pointer -funroll-loops -fpeel-loops -ftracer -finline-functions  (test for excess errors)
FAIL: gfortran.dg/class_to_type_1.f03   -O3 -g  (internal compiler error: in smallest_mode_for_size, at stor-layout.cc:356)
FAIL: gfortran.dg/class_to_type_1.f03   -O3 -g  (test for excess errors)
FAIL: gfortran.dg/class_array_4.f03   -O3 -fomit-frame-pointer -funroll-loops -fpeel-loops -ftracer -finline-functions  execution test
FAIL: gfortran.dg/cshift_bounds_4.f90   -O2  (internal compiler error: in smallest_mode_for_size, at stor-layout.cc:356)
FAIL: gfortran.dg/cshift_bounds_4.f90   -O2  (test for excess errors)
FAIL: gfortran.dg/cshift_bounds_4.f90   -O3 -fomit-frame-pointer -funroll-loops -fpeel-loops -ftracer -finline-functions  (internal compiler error: in smallest_mode_for_size, at stor-layout.cc:356)
FAIL: gfortran.dg/cshift_bounds_4.f90   -O3 -fomit-frame-pointer -funroll-loops -fpeel-loops -ftracer -finline-functions  (test for excess errors)
FAIL: gfortran.dg/cshift_bounds_4.f90   -O3 -g  (internal compiler error: in smallest_mode_for_size, at stor-layout.cc:356)
FAIL: gfortran.dg/cshift_bounds_4.f90   -O3 -g  (test for excess errors)

One of the case:

program main
  integer, dimension(:,:), allocatable :: a, b
  integer, dimension(:), allocatable :: sh
  allocate (a(2,2))
  allocate (b(2,2))
  allocate (sh(3))
  a = 1
  b = cshift(a,sh)
end program main
Comment 1 GCC Commits 2023-09-27 08:28:21 UTC
The master branch has been updated by Pan Li <panli@gcc.gnu.org>:

https://gcc.gnu.org/g:073849da3dfd5cabbfd4492a40a17b207b4a7630

commit r14-4291-g073849da3dfd5cabbfd4492a40a17b207b4a7630
Author: Juzhe-Zhong <juzhe.zhong@rivai.ai>
Date:   Wed Sep 27 06:47:12 2023 +0800

    DSE: Fix ICE when the mode with access_size don't exist on the target[PR111590]
    
    hen doing fortran test with 'V' extension enabled on RISC-V port.
    I saw multiple ICE: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=111590
    
    The root cause is on DSE:
    
    internal compiler error: in smallest_mode_for_size, at stor-layout.cc:356
    0x1918f70 smallest_mode_for_size(poly_int<2u, unsigned long>, mode_class)
            ../../../../gcc/gcc/stor-layout.cc:356
    0x11f75bb smallest_int_mode_for_size(poly_int<2u, unsigned long>)
            ../../../../gcc/gcc/machmode.h:916
    0x3304141 find_shift_sequence
            ../../../../gcc/gcc/dse.cc:1738
    0x3304f1a get_stored_val
            ../../../../gcc/gcc/dse.cc:1906
    0x3305377 replace_read
            ../../../../gcc/gcc/dse.cc:2010
    0x3306226 check_mem_read_rtx
            ../../../../gcc/gcc/dse.cc:2310
    0x330667b check_mem_read_use
            ../../../../gcc/gcc/dse.cc:2415
    
    After investigations, DSE is trying to do optimization like this following codes:
    
    (insn 86 85 87 9 (set (reg:V4DI 168)
            (mem/u/c:V4DI (reg/f:DI 171) [0  S32 A128])) "bug.f90":6:18 discrim 6 1167 {*movv4di}
         (expr_list:REG_EQUAL (const_vector:V4DI [
                    (const_int 4 [0x4])
                    (const_int 1 [0x1]) repeated x2
                    (const_int 3 [0x3])
                ])
            (nil)))
    
    (set (mem) (reg:V4DI 168))
    
    Then it ICE on: auto new_mode = smallest_int_mode_for_size (access_size * BITS_PER_UNIT);
    
    The access_size may be 24 or 32. We don't have such integer modes with these size so it ICE.
    
    TODO: The better way maybe make DSE use native_encode_rtx/native_decode_rtx
          but I don't know how to do that.  So let's quickly fix this issue, we
          can improve the fix later.
    
            PR target/111590
    
    gcc/ChangeLog:
    
            * dse.cc (find_shift_sequence): Check the mode with access_size exist on the target.
Comment 2 JuzheZhong 2023-09-27 08:29:18 UTC
fixed