[Bug middle-end/65163] New: [5 Regression][SH] ICE in decompose at rtl.h:2007

["olegendo at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=65163

            Bug ID: 65163
           Summary: [5 Regression][SH] ICE in decompose at rtl.h:2007
           Product: gcc
           Version: 5.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: middle-end
          Assignee: unassigned at gcc dot gnu.org
          Reporter: olegendo at gcc dot gnu.org
            Target: sh*-*-*

The following example:

typedef unsigned int uint32_t;
union unaligned_32 { uint32_t l; } __attribute__((packed));

int
test (unsigned char* buf, int bits_per_component)
{
  (((union unaligned_32 *)(buf))->l) = __builtin_bswap32 (bits_per_component ==
10 ? 1 : 0);

  return 0;
}


compiled with -m4 -ml -O2 results in:

 internal compiler error: in decompose, at rtl.h:2007
 }
 ^
0x8708fa1 wi::int_traits<std::pair<rtx_def*, machine_mode> >::decompose(long
long*, unsigned int, std::pair<rtx_def*, machine_mode> const&)
    ../../gcc-trunk/gcc/rtl.h:2005
0x8708fa1 wi::int_traits<std::pair<rtx_def*, machine_mode> >::decompose(long
long*, unsigned int, std::pair<rtx_def*, machine_mode> const&)
    ../../gcc-trunk/gcc/simplify-rtx.c:3717
0x8708fa1 wide_int_ref_storage<std::pair<rtx_def*, machine_mode> >
    ../../gcc-trunk/gcc/wide-int.h:948
0x8708fa1 generic_wide_int<std::pair<rtx_def*, machine_mode> >
    ../../gcc-trunk/gcc/wide-int.h:725
0x8708fa1 neg_p<std::pair<rtx_def*, machine_mode> >
    ../../gcc-trunk/gcc/wide-int.h:1694
0x8708fa1 simplify_const_binary_operation(rtx_code, machine_mode, rtx_def*,
rtx_def*)
    ../../gcc-trunk/gcc/simplify-rtx.c:4029
0x87077e3 simplify_binary_operation(rtx_code, machine_mode, rtx_def*, rtx_def*)
    ../../gcc-trunk/gcc/simplify-rtx.c:1987
0x870a9b6 simplify_gen_binary
    ../../gcc-trunk/gcc/simplify-rtx.c:212
0x8b6b047 if_then_else_cond
    ../../gcc-trunk/gcc/combine.c:8885
0x8b73a22 combine_simplify_rtx
    ../../gcc-trunk/gcc/combine.c:5492
0x8b7679f subst
    ../../gcc-trunk/gcc/combine.c:5429
0x8b76518 subst
    ../../gcc-trunk/gcc/combine.c:5374
0x8b76518 subst
    ../../gcc-trunk/gcc/combine.c:5374
0x8b78f03 try_combine
    ../../gcc-trunk/gcc/combine.c:3273
0x8b7f44f combine_instructions
    ../../gcc-trunk/gcc/combine.c:1309
0x8b7f44f rest_of_handle_combine
    ../../gcc-trunk/gcc/combine.c:14194
0x8b7f44f execute
    ../../gcc-trunk/gcc/combine.c:14237

... when combine tries to simplify the following rtx:

(and:SI (rotate:SI (reg:SI 170)
        (const_int 16 [0x10]))
    (const_int 4294901760 [0xffff0000]))

The problem is that in sh.md the constant 0xffff0000 is not written as sign
extended hwi values.

It's actually a latent bug, which seems to have gone unnoticed so far.