[Bug ipa/70348] [6 Regression][openacc] ICE in visit_ref_for_mod_analysis, at ipa-prop.c

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

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=70348

--- Comment #2 from Martin Jambor <jamborm at gcc dot gnu.org> ---
The problem is that there is a PARM_DECL in the IL of the function
which is not listed among DECL_ARGUMENTS of the function:

The function we are in is:

(gdb) call debug_generic_expr(cfun->decl)
foo._omp_fn.0

but look at the context of the PARM_DECL in question:

(gdb) call debug_tree (op)
 <parm_decl 0x7ffff6a5cc80 sum
    type <integer_type 0x7ffff6891888 unsigned int sizes-gimplified public
unsigned SI
        size <integer_cst 0x7ffff688dee8 constant 32>
        unit size <integer_cst 0x7ffff688df00 constant 4>
        align 32 symtab 0 alias set -1 canonical type 0x7ffff6891888 precision
32 min <integer_cst 0x7ffff688df18 0> max <integer_cst 0x7ffff688ded0
4294967295> context <translation_unit_decl 0x7ffff6a671e0 D.2915>
        pointer_to_this <pointer_type 0x7ffff68b2498>>
    addressable used unsigned SI file pr70348.c line 7 col 26 size <integer_cst
0x7ffff688dee8 32> unit size <integer_cst 0x7ffff688df00 4>
    align 32 context <function_decl 0x7ffff6a627e0 foo> arg-type <integer_type
0x7ffff6891888 unsigned int>>


Also, if you check the uid of the PARM_DECL:

(gdb) p op->decl_minimal.uid
$3 = 2907

you will see that it corresponds to a parameter the original function
foo, from which OpenACC outlined bits to foo._omp_fn.0:

   foo (intD.6 nD.2906, unsigned intD.9 sumD.2907)


And just by the way, because of the context mismatch, the testcase
ICEs in expand_expr_real_1 when compiled at -O0:

pr70348.c: In function âfoo._omp_fn.0â:
pr70348.c:11:9: internal compiler error: in expand_expr_real_1, at expr.c:9651
 #pragma acc parallel reduction(+:sum)
         ^~~
0xa61521 expand_expr_real_1(tree_node*, rtx_def*, machine_mode,
expand_modifier, rtx_def**, bool)
        /home/mjambor/gcc/icln/src/gcc/expr.c:9645
0xa5a4c3 expand_expr_real(tree_node*, rtx_def*, machine_mode, expand_modifier,
rtx_def**, bool)
        /home/mjambor/gcc/icln/src/gcc/expr.c:7962
0xa5178b store_expr_with_bounds(tree_node*, rtx_def*, int, bool, bool,
tree_node*)
        /home/mjambor/gcc/icln/src/gcc/expr.c:5406
0xa5039c expand_assignment(tree_node*, tree_node*, bool)
        /home/mjambor/gcc/icln/src/gcc/expr.c:5175
0x90e4bc expand_gimple_stmt_1
        /home/mjambor/gcc/icln/src/gcc/cfgexpand.c:3618
0x90e8ad expand_gimple_stmt
        /home/mjambor/gcc/icln/src/gcc/cfgexpand.c:3714
0x9159be expand_gimple_basic_block
        /home/mjambor/gcc/icln/src/gcc/cfgexpand.c:5720
0x917487 execute
        /home/mjambor/gcc/icln/src/gcc/cfgexpand.c:6335

All in all, this is an OpenACC lowering/expansion bug.