[Bug fortran/83975] [8 Regression] ICE in set_parm_default_def_partition, at tree-ssa-coalesce.c:1919

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=83975

--- Comment #4 from Richard Biener <rguenth at gcc dot gnu.org> ---
Somehow the VAR_DECL for 'y' is in the PARM_DECL chain for the FUNCTION_DECL s:

 <function_decl 0x7ffff6a52f00 s
    type <function_type 0x7ffff6a53f18
        type <void_type 0x7ffff68a8f18 void VOID
            align:8 warn_if_not_align:0 symtab:0 alias-set -1 canonical-type
0x7ffff68a8f18
            pointer_to_this <pointer_type 0x7ffff68af0a8>>
        QI
        size <integer_cst 0x7ffff6894cd8 constant 8>
        unit-size <integer_cst 0x7ffff6894cf0 constant 1>
        align:8 warn_if_not_align:0 symtab:0 alias-set -1 canonical-type
0x7ffff6a53e70
        attributes <tree_list 0x7ffff6a55578
            purpose <identifier_node 0x7ffff6900d48 fn spec>
            value <tree_list 0x7ffff6a55550
                value <string_cst 0x7ffff6a48900 constant ".w">>>
        arg-types <tree_list 0x7ffff6a55528 value <reference_type
0x7ffff6a53dc8>
            chain <tree_list 0x7ffff6a55500 value <integer_type 0x7ffff68a8738
integer(kind=8)>
                chain <tree_list 0x7ffff68a7aa0 value <void_type 0x7ffff68a8f18
void>>>>>
    public static QI t.f90:1:0 align:8 warn_if_not_align:0 context
<translation_unit_decl 0x7ffff689e168 t.f90> initial <block 0x7ffff6a58060>
    result <result_decl 0x7ffff689e1e0 D.3758 type <void_type 0x7ffff68a8f18
void>
        ignored VOID t.f90:1:0
        align:8 warn_if_not_align:0 context <function_decl 0x7ffff6a52f00 s>>
    (mem:QI (symbol_ref:DI ("s_") [flags 0x3] <function_decl 0x7ffff6a52f00 s>)
[0  S1 A8])
    arguments <parm_decl 0x7ffff6a41280 x
        type <reference_type 0x7ffff6a531f8 type <array_type 0x7ffff6a530a8>
            unsigned restrict DI
            size <integer_cst 0x7ffff6894be8 constant 64>
            unit-size <integer_cst 0x7ffff6894c00 constant 8>
            align:64 warn_if_not_align:0 symtab:0 alias-set -1
structural-equality>
        readonly used unsigned DI passed-by-reference t.f90:1:0 size
<integer_cst 0x7ffff6894be8 64> unit-size <integer_cst 0x7ffff6894c00 8>
        align:64 warn_if_not_align:0 context <function_decl 0x7ffff6a52f00 s>
        arg-type <reference_type 0x7ffff6a53dc8 type <array_type
0x7ffff6a53c78>
            unsigned restrict DI size <integer_cst 0x7ffff6894be8 64> unit-size
<integer_cst 0x7ffff6894c00 8>
            align:64 warn_if_not_align:0 symtab:0 alias-set -1 canonical-type
0x7ffff6a53dc8>
        chain <parm_decl 0x7ffff6a41200 _x type <integer_type 0x7ffff68a8738
integer(kind=8)>
            readonly used DI t.f90:1:0 size <integer_cst 0x7ffff6894be8 64>
unit-size <integer_cst 0x7ffff6894c00 8>
            align:64 warn_if_not_align:0 context <function_decl 0x7ffff6a52f00
s> arg-type <integer_type 0x7ffff68a8738 integer(kind=8)> chain <var_decl
0x7ffff7fefab0 y>>>