On Mon, Nov 23, 2015 at 2:45 PM, Ilya Enkovich <enkovich....@gmail.com> wrote:
> On 23 Nov 14:29, Richard Biener wrote:
>> On Mon, Nov 23, 2015 at 12:33 PM, Ilya Enkovich <enkovich....@gmail.com>
>> wrote:
>> >
>> > I see. But it should still be OK to check type in case of strict
>> > aliasing, right?
>>
>> No, memcpy is always "no-strict-aliasing"
>>
>
> Thanks a lot for help! Here is a variant with a size check only as
> you originally suggested. Is it OK for trunk and gcc-5-branch if
> no regressions?
Ok.
Thanks,
Richard.
> Thanks,
> Ilya
> --
> gcc/
>
> 2015-11-23 Ilya Enkovich <enkovich....@gmail.com>
>
> * gimple-fold.c: Include ipa-chkp.h.
> (gimple_fold_builtin_memory_op): Don't fold call if we
> are going to instrument it and it may copy pointers.
>
> gcc/testsuite/
>
> 2015-11-23 Ilya Enkovich <enkovich....@gmail.com>
>
> * gcc.target/i386/mpx/pr68337-1.c: New test.
> * gcc.target/i386/mpx/pr68337-2.c: New test.
>
>
> diff --git a/gcc/gimple-fold.c b/gcc/gimple-fold.c
> index 1ab20d1..6ff5e26 100644
> --- a/gcc/gimple-fold.c
> +++ b/gcc/gimple-fold.c
> @@ -53,6 +53,7 @@ along with GCC; see the file COPYING3. If not see
> #include "gomp-constants.h"
> #include "optabs-query.h"
> #include "omp-low.h"
> +#include "ipa-chkp.h"
>
>
> /* Return true when DECL can be referenced from current unit.
> @@ -664,6 +665,18 @@ gimple_fold_builtin_memory_op (gimple_stmt_iterator *gsi,
> unsigned int src_align, dest_align;
> tree off0;
>
> + /* Inlining of memcpy/memmove may cause bounds lost (if we copy
> + pointers as wide integer) and also may result in huge function
> + size because of inlined bounds copy. Thus don't inline for
> + functions we want to instrument. */
> + if (flag_check_pointer_bounds
> + && chkp_instrumentable_p (cfun->decl)
> + /* Even if data may contain pointers we can inline if copy
> + less than a pointer size. */
> + && (!tree_fits_uhwi_p (len)
> + || compare_tree_int (len, POINTER_SIZE_UNITS) >= 0))
> + return false;
> +
> /* Build accesses at offset zero with a ref-all character type. */
> off0 = build_int_cst (build_pointer_type_for_mode (char_type_node,
> ptr_mode, true), 0);
> diff --git a/gcc/testsuite/gcc.target/i386/mpx/pr68337-1.c
> b/gcc/testsuite/gcc.target/i386/mpx/pr68337-1.c
> new file mode 100644
> index 0000000..3f8d79d
> --- /dev/null
> +++ b/gcc/testsuite/gcc.target/i386/mpx/pr68337-1.c
> @@ -0,0 +1,32 @@
> +/* { dg-do run } */
> +/* { dg-options "-fcheck-pointer-bounds -mmpx" } */
> +
> +#include "mpx-check.h"
> +
> +#define N 2
> +
> +extern void abort ();
> +
> +static int
> +mpx_test (int argc, const char **argv)
> +{
> + char ** src = (char **)malloc (sizeof (char *) * N);
> + char ** dst = (char **)malloc (sizeof (char *) * N);
> + int i;
> +
> + for (i = 0; i < N; i++)
> + src[i] = __bnd_set_ptr_bounds (argv[0] + i, i + 1);
> +
> + __builtin_memcpy(dst, src, sizeof (char *) * N);
> +
> + for (i = 0; i < N; i++)
> + {
> + char *p = dst[i];
> + if (p != argv[0] + i
> + || __bnd_get_ptr_lbound (p) != p
> + || __bnd_get_ptr_ubound (p) != p + i)
> + abort ();
> + }
> +
> + return 0;
> +}
> diff --git a/gcc/testsuite/gcc.target/i386/mpx/pr68337-2.c
> b/gcc/testsuite/gcc.target/i386/mpx/pr68337-2.c
> new file mode 100644
> index 0000000..8845cca
> --- /dev/null
> +++ b/gcc/testsuite/gcc.target/i386/mpx/pr68337-2.c
> @@ -0,0 +1,9 @@
> +/* { dg-do compile } */
> +/* { dg-options "-fcheck-pointer-bounds -mmpx" } */
> +/* { dg-final { scan-assembler-not "memcpy" } } */
> +
> +void
> +test (void *dst, void *src)
> +{
> + __builtin_memcpy (dst, src, sizeof (char *) / 2);
> +}
