Hi Richard and Jakub
Since 4.6 contains the same bug, I would like to back port it to 4.6
branch. Could you approve it for 4.6?
Jing and Doug
Could you approve it for google/gcc-4_6-mobile branch?
thanks
Carrot
On Mon, Feb 6, 2012 at 9:14 PM, Richard Guenther
<richard.guent...@gmail.com> wrote:
> On Mon, Feb 6, 2012 at 2:01 PM, Jakub Jelinek <ja...@redhat.com> wrote:
>> Hi!
>>
>> The attached testcase is miscompiled on arm*, by doing a sibcall when setup
>> of one argument overwrites incoming arguments used to setup parameters in
>> later insns.
>> The reason why
>> mem_overlaps_already_clobbered_arg_p/check_sibcall_argument_overlap
>> fails to detect is that the caller has non-zero
>> crtl->args.pretend_args_size, and in that case the base:
>> /* The argument block when performing a sibling call is the
>> incoming argument block. */
>> if (pass == 0)
>> {
>> argblock = crtl->args.internal_arg_pointer;
>> argblock
>> #ifdef STACK_GROWS_DOWNWARD
>> = plus_constant (argblock, crtl->args.pretend_args_size);
>> #else
>> = plus_constant (argblock, -crtl->args.pretend_args_size);
>> #endif
>> stored_args_map = sbitmap_alloc (args_size.constant);
>> sbitmap_zero (stored_args_map);
>> }
>> apparently isn't virtual-incoming-rtx, but that plus pretend_args_size
>> (8 in this case). When we store bits into stored_args_map sbitmap,
>> we use arg->locate.slot_offset.constant based values (or something different
>> for ARGS_GROW_DOWNWARD, but when mem_overlaps_already_clobbered_arg_p is
>> testing those bits, it uses just virtual-incoming-rtx offsets (or something
>> different for ARGS_GROW_DOWNWARD). This patch fixes it by adjusting the
>> virtual-incoming-rtx relative offset to be actually argblock relative
>> offset.
>>
>> Bootstrapped/regtested on x86_64-linux and i686-linux and tested on the
>> testcase on arm cross. Ok for trunk?
>
> Ok.
>
> Thanks,
> Richard.
>
>> 2012-02-06 Jakub Jelinek <ja...@redhat.com>
>>
>> PR target/52129
>> * calls.c (mem_overlaps_already_clobbered_arg_p): If val is
>> CONST_INT_P, subtract resp. add crtl->args.pretend_args_size to it.
>>
>> * gcc.c-torture/execute/pr52129.c: New test.
>>
>> --- gcc/calls.c.jj 2012-02-01 14:44:27.000000000 +0100
>> +++ gcc/calls.c 2012-02-06 10:19:12.112132905 +0100
>> @@ -1808,6 +1808,11 @@ mem_overlaps_already_clobbered_arg_p (rt
>> return true;
>> else
>> i = INTVAL (val);
>> +#ifdef STACK_GROWS_DOWNWARD
>> + i -= crtl->args.pretend_args_size;
>> +#else
>> + i += crtl->args.pretend_args_size;
>> +#endif
>>
>> #ifdef ARGS_GROW_DOWNWARD
>> i = -i - size;
>> --- gcc/testsuite/gcc.c-torture/execute/pr52129.c.jj 2012-02-06
>> 10:27:50.988876791 +0100
>> +++ gcc/testsuite/gcc.c-torture/execute/pr52129.c 2012-02-06
>> 10:25:26.000000000 +0100
>> @@ -0,0 +1,28 @@
>> +/* PR target/52129 */
>> +
>> +extern void abort (void);
>> +struct S { void *p; unsigned int q; };
>> +struct T { char a[64]; char b[64]; } t;
>> +
>> +__attribute__((noinline, noclone)) int
>> +foo (void *x, struct S s, void *y, void *z)
>> +{
>> + if (x != &t.a[2] || s.p != &t.b[5] || s.q != 27 || y != &t.a[17] || z !=
>> &t.b[17])
>> + abort ();
>> + return 29;
>> +}
>> +
>> +__attribute__((noinline, noclone)) int
>> +bar (void *x, void *y, void *z, struct S s, int t, struct T *u)
>> +{
>> + return foo (x, s, &u->a[t], &u->b[t]);
>> +}
>> +
>> +int
>> +main ()
>> +{
>> + struct S s = { &t.b[5], 27 };
>> + if (bar (&t.a[2], (void *) 0, (void *) 0, s, 17, &t) != 29)
>> + abort ();
>> + return 0;
>> +}
>>
>> Jakub
