https://gcc.gnu.org/bugzilla/show_bug.cgi?id=122757
--- Comment #4 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
Some debug:
```
Breakpoint 1, precompute_register_parameters (num_actuals=2, args=0x4aa4090,
reg_parm_seen=0x7fffffffbd6c) at ../../gcc/calls.cc:1022
1022 args[i].value = expand_normal (args[i].tree_value);
(gdb) p debug_generic_expr(args[i].tree_value
A syntax error in expression, near `'.
(gdb) p debug_generic_expr(args[i].tree_value)
*.LC0
$1 = void
(gdb) p debug_rtx(args[i].reg)
(parallel:BLK [
(expr_list:REG_DEP_TRUE (reg:DI 2 x2)
(const_int 0 [0]))
(expr_list:REG_DEP_TRUE (reg:DI 3 x3)
(const_int 8 [0x8]))
])
$2 = void
(gdb) next
1023 preserve_temp_slots (args[i].value);
(gdb) p debug_rtx(args[i].value)
(mem/u/c:BLK (reg/f:DI 101) [0 A64])
$3 = void
(gdb) p debug_tree(args[i].tree_value)
<var_decl 0x7ffff732ded8 *.LC0
type <record_type 0x7ffff7321930 IF sizes-gimplified BLK
size <integer_cst 0x7ffff741e390 constant 96>
unit-size <integer_cst 0x7ffff733b330 constant 12>
align:32 warn_if_not_align:0 symtab:0 alias-set -1 canonical-type
0x7ffff7321888
fields <field_decl 0x7ffff731f640 a type <integer_type 0x7ffff741c5e8
int>
SI t.c:2:25
size <integer_cst 0x7ffff741e180 constant 32>
unit-size <integer_cst 0x7ffff741e198 constant 4>
align:32 warn_if_not_align:0 offset_align 128 decl_not_flexarray: 1
offset <integer_cst 0x7ffff7402f60 constant 0>
bit-offset <integer_cst 0x7ffff7402fa8 constant 0> context
<record_type 0x7ffff7321888 IF> chain <field_decl 0x7ffff731f6e0 b>>
pointer_to_this <pointer_type 0x7ffff737b000> chain <type_decl
0x7ffff731f5a0 D.4585>>
readonly used static ignored in-constant-pool BLK (null):0:0 size
<integer_cst 0x7ffff741e390 96> unit-size <integer_cst 0x7ffff733b330 12>
align:64 warn_if_not_align:0 initial <constructor 0x7ffff733b348>
(mem/u/c:BLK (symbol_ref/f:DI ("*.LC0") [flags 0x82] <var_decl
0x7ffff732ded8 *.LC0>) [0 A64])>
```
So expand_normal pushes the symbol_ref into its own register to begin with.
Then emit_group_load_into_temps has no way to know it is loading from a
constant decl ...
