[PATCH] Fix sibcall argument overlap checking if pretend_args_size (PR target/52129)

[PATCH] Fix sibcall argument overlap checking if pretend_args_size (PR target/52129)

[Jakub Jelinek]

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?

2012-02-06  Jakub Jelinek  <jakub@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

Re: [PATCH] Fix sibcall argument overlap checking if pretend_args_size (PR target/52129)

[Richard Guenther]

On Mon, Feb 6, 2012 at 2:01 PM, Jakub Jelinek <jakub@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  <jakub@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

Re: [PATCH] Fix sibcall argument overlap checking if pretend_args_size (PR target/52129)

[Carrot Wei]

Hi Jakub

Instead of disabling the sibcall, it could also be a valid tail call
optimization by moving the str after ldmia, and change the used
register(It should be handled by RA automatically), as following

         ...
          add     r4, r1, r4, lsl #2
          ldmia   r2, {r1, r2}
          str     r4, [sp, #48]
          ...

thanks
Carrot

On Mon, Feb 6, 2012 at 9:01 PM, Jakub Jelinek <jakub@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?
>
> 2012-02-06  Jakub Jelinek  <jakub@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

Re: [PATCH] Fix sibcall argument overlap checking if pretend_args_size (PR target/52129)

[Carrot Wei]

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.guenther@gmail.com> wrote:
> On Mon, Feb 6, 2012 at 2:01 PM, Jakub Jelinek <jakub@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  <jakub@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

Re: [PATCH] Fix sibcall argument overlap checking if pretend_args_size (PR target/52129)

[Jakub Jelinek]

On Thu, Feb 09, 2012 at 04:54:59PM +0800, Carrot Wei wrote:
> 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?

Yes, this is ok.  I'm sorry for deferring too many 4.6 backports for way too
long, will get to it eventually.

	Jakub

Re: [PATCH] Fix sibcall argument overlap checking if pretend_args_size (PR target/52129)

[Jing Yu]

On Thu, Feb 9, 2012 at 12:54 AM, Carrot Wei <carrot@google.com> wrote:
> 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?
>

OK for google/gcc-4_6-mobile and gcc-4_6_2-mobile

Jing

> thanks
> Carrot
>
> On Mon, Feb 6, 2012 at 9:14 PM, Richard Guenther
> <richard.guenther@gmail.com> wrote:
>> On Mon, Feb 6, 2012 at 2:01 PM, Jakub Jelinek <jakub@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  <jakub@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

Re: [PATCH] Fix sibcall argument overlap checking if pretend_args_size (PR target/52129)

[Carrot Wei]

On Fri, Feb 10, 2012 at 2:13 PM, Jing Yu <jingyu@google.com> wrote:
> On Thu, Feb 9, 2012 at 12:54 AM, Carrot Wei <carrot@google.com> wrote:
>> 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?
>>
>
> OK for google/gcc-4_6-mobile and gcc-4_6_2-mobile
>
> Jing
>

Bootstrapped/regtested on x86_64-linux and regtested on arm qemu.
Committed to both google/gcc-4_6-mobile and google/gcc-4_6_2-mobile.

thanks
Carrot