On Tue, May 10, 2011 at 2:52 AM, Jakub Jelinek <ja...@redhat.com> wrote:
> On Mon, May 09, 2011 at 01:35:39PM -0700, H.J. Lu wrote:
>> (gdb) call debug_rtx (rtl)
>> (var_location d (mem/s/j:SI (plus:DI (subreg:DI (ashift:SI
>> (entry_value:SI (reg:SI 5 di [ i ]))
>> (const_int 2 [0x2])) 0)
>> (symbol_ref:DI ("a") <var_decl 0x7ffff0606000 a>)) [0 a S4 A32]))
>> (gdb)
>
> Ugh, paradoxical subreg? Doesn't that say that the upper 32-bits are
> undefined? Surely that ought to be zero_extend, sign_extend or something
> similarly well defined...
>
With
[hjl@gnu-6 pr48853]$ cat x.i
extern void abort (void);
int a[1024];
volatile short int v;
int
foo (int i, int j)
{
int d = a[i];
++v;
return ++j;
}
rtl expansion has
;; Start of basic block ( 2) -> 3
;; Pred edge 2 [100.0%] (fallthru)
(note 6 4 7 3 [bb 3] NOTE_INSN_BASIC_BLOCK)
(debug_insn 7 6 8 3 (var_location:SI D#1 (mem/s/j:SI (plus:DI (subreg:DI (ashift
:SI (entry_value:SI (reg:SI 5 di [ i ]))
(const_int 2 [0x2])) 0)
(symbol_ref:DI ("a") <var_decl 0x7ffff0a83000 a>)) [0 a S4 A32])) x
.i:8 -1
(nil))
Where should I look?
Thanks.
--
H.J.
