[PATCH] Bail out HARD_REGISTER vars in asan (PR sanitizer/81224).

[Martin Liška]

Similar to what we do for UBSAN and TSAN, DECL_HARD_REGISTER variables should 
not
be instrumented.

Patch can bootstrap on ppc64le-redhat-linux and survives regression tests.

Ready to be installed?
Martin

gcc/ChangeLog:

2017-06-27  Martin Liska  <mli...@suse.cz>

        PR sanitizer/81224
        * asan.c (instrument_derefs): Bail out inner references
        that are hard register variables.

gcc/testsuite/ChangeLog:

2017-06-27  Martin Liska  <mli...@suse.cz>

        PR sanitizer/81224
        * gcc.dg/asan/pr81224.c: New test.
---
 gcc/asan.c                          |  3 +++
 gcc/testsuite/gcc.dg/asan/pr81224.c | 10 ++++++++++
 2 files changed, 13 insertions(+)
 create mode 100644 gcc/testsuite/gcc.dg/asan/pr81224.c



diff --git a/gcc/asan.c b/gcc/asan.c
index e730530930b..3f814819add 100644
--- a/gcc/asan.c
+++ b/gcc/asan.c
@@ -1875,6 +1875,9 @@ instrument_derefs (gimple_stmt_iterator *iter, tree t,
       || bitsize != size_in_bytes * BITS_PER_UNIT)
     return;
 
+  if (VAR_P (inner) && DECL_HARD_REGISTER (inner))
+    return;
+
   if (VAR_P (inner)
       && offset == NULL_TREE
       && bitpos >= 0
diff --git a/gcc/testsuite/gcc.dg/asan/pr81224.c b/gcc/testsuite/gcc.dg/asan/pr81224.c
new file mode 100644
index 00000000000..5586fe04391
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/asan/pr81224.c
@@ -0,0 +1,10 @@
+/* PR sanitizer/80659 */
+/* { dg-do compile { target { i?86-*-* x86_64-*-* } } } */
+
+int a;
+int
+b ()
+{
+  register __attribute__ ((__vector_size__ (sizeof (int)))) int c asm("xmm0");
+  return c[a];
+}