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Re: [PATCH, PR68337] Don't fold memcpy/memmove we want to instrument
- From: Ilya Enkovich <enkovich dot gnu at gmail dot com>
- To: Richard Biener <richard dot guenther at gmail dot com>
- Cc: Bernd Schmidt <bschmidt at redhat dot com>, GCC Patches <gcc-patches at gcc dot gnu dot org>
- Date: Mon, 23 Nov 2015 16:45:05 +0300
- Subject: Re: [PATCH, PR68337] Don't fold memcpy/memmove we want to instrument
- Authentication-results: sourceware.org; auth=none
- References: <564E02FE dot 5020503 at redhat dot com> <BBF11FD1-3884-4D6A-8FF7-7F4A658B5DBF at gmail dot com> <20151120130827 dot GH42296 at msticlxl57 dot ims dot intel dot com> <CAFiYyc3F=-hD_zkWSY51wv0t2OQRYvJwzK4VS8Hp-Cbs3cP1og at mail dot gmail dot com> <20151120143020 dot GI42296 at msticlxl57 dot ims dot intel dot com> <CAFiYyc1SoGMuDjdr02HxRqQkFc7CV-nf4+u9xoa2icr5vd_BTg at mail dot gmail dot com> <20151123101013 dot GA11184 at msticlxl57 dot ims dot intel dot com> <CAFiYyc0xcT6cKPo6YnB0ysEhKCxWmfMrh=WcCXA6rKHi9od1NQ at mail dot gmail dot com> <20151123113302 dot GB11184 at msticlxl57 dot ims dot intel dot com> <CAFiYyc1V8Sp2T6_YAXK6ZVW3rnj24QuwpaK2_hGJgJmGVGyghQ at mail dot gmail dot com>
On 23 Nov 14:29, Richard Biener wrote:
> On Mon, Nov 23, 2015 at 12:33 PM, Ilya Enkovich <enkovich.gnu@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?
Thanks,
Ilya
--
gcc/
2015-11-23 Ilya Enkovich <enkovich.gnu@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.gnu@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);
+}
- References:
- Re: [PATCH, PR68337] Don't fold memcpy/memmove we want to instrument
- Re: [PATCH, PR68337] Don't fold memcpy/memmove we want to instrument
- Re: [PATCH, PR68337] Don't fold memcpy/memmove we want to instrument
- Re: [PATCH, PR68337] Don't fold memcpy/memmove we want to instrument
- Re: [PATCH, PR68337] Don't fold memcpy/memmove we want to instrument
- Re: [PATCH, PR68337] Don't fold memcpy/memmove we want to instrument
- Re: [PATCH, PR68337] Don't fold memcpy/memmove we want to instrument
- Re: [PATCH, PR68337] Don't fold memcpy/memmove we want to instrument
- Re: [PATCH, PR68337] Don't fold memcpy/memmove we want to instrument
- Re: [PATCH, PR68337] Don't fold memcpy/memmove we want to instrument