gcc: Bring updates from Google's enhanced gcc-4.2.1.

Google released and enhanced version of gcc-4.2.1 plus their local
patches for Android[1].

The patches are owned by Google and the license hasn't been changed
from  the original GPLv2. We are only bringing a subset of the
available patches that may be helpful in FreeBSD. Changes specific
to android are not included.

From the README.google file[1].

Patches applied to google_vendor_src_branch/gcc/gcc-4.2.1:

gcc/Makefile.in
gcc/c-common.c
gcc/c-common.h
gcc/c-opts.c
gcc/c-typeck.c
gcc/cp/typeck.c
gcc/doc/invoke.texi
gcc/flags.h
gcc/opts.c
gcc/tree-flow.h
gcc/tree-ssa-alias-warnings.c
gcc/tree-ssa-alias.c

 Backport of -Wstrict-aliasing from mainline.
  Silvius Rus <rus@google.com>

gcc/coverage.c:
  Patch coverage_checksum_string for PR 25351.
  Seongbae Park <spark@google.com>
  Not yet submitted to FSF.

gcc/c-opts.c
gcc/c-ppoutput.c
gcc/c.opt
gcc/doc/cppopts.texi
libcpp/Makefile.in
libcpp/directives-only.c
libcpp/directives.c
libcpp/files.c
libcpp/include/cpplib.h
libcpp/init.c
libcpp/internal.h
libcpp/macro.c
  Support for -fdirectives-only.
  Ollie Wild <aaw@google.com>.
  Submitted to FSF but not yet approved.

libstdc++-v3/include/ext/hashtable.h
  http://b/742065
  http://b/629994
  Reduce min size of hashtable for hash_map, hash_set from 53 to 5

libstdc++-v3/include/ext/hashtable.h
  http://b/629994
  Do not iterate over buckets if hashtable is empty.

gcc/common.opt
gcc/doc/invoke.texi
gcc/flags.h
gcc/gimplify.c
gcc/opts.c
  Add Saito's patch for -finstrument-functions-exclude-* options.

gcc/common.opt
gcc/doc/invoke.texi
gcc/final.c
gcc/flags.h
gcc/opts.c
gcc/testsuite/gcc.dg/Wframe-larger-than.c
  Add a new flag -Wframe-larger-than- which enables a new warning
  when a frame size of a function is larger than specified.
  This patch hasn't been integrated into gcc mainline yet.

gcc/tree-vrp.c
  Add a hack to avoid using ivopts information for pointers starting
  at constant values.

Reference:

[1]
https://android.googlesource.com/toolchain/gcc/+/master/gcc-4.2.1/

Obtained from:	Google Inc.
MFC after:	3 weeks

1 files changed, 7 insertions, 1 deletions

diff --git a/contrib/gcc/tree-vrp.c b/contrib/gcc/tree-vrp.c
index 0c9824d..f97bd61 100644
--- a/contrib/gcc/tree-vrp.c
+++ b/contrib/gcc/tree-vrp.c
@@ -2509,12 +2509,18 @@ adjust_range_with_scev (value_range_t *vr, struct loop *loop, tree stmt,
 				true))
     return;
 
+  type = TREE_TYPE (var);
+
+  /* If we see a pointer type starting at a constant, then we have an
+     unusual ivopt.  It may legitimately wrap.  */
+  if (POINTER_TYPE_P (type) && is_gimple_min_invariant (init))
+    return;
+
   /* We use TYPE_MIN_VALUE and TYPE_MAX_VALUE here instead of
      negative_overflow_infinity and positive_overflow_infinity,
      because we have concluded that the loop probably does not
      wrap.  */
 
-  type = TREE_TYPE (var);
   if (POINTER_TYPE_P (type) || !TYPE_MIN_VALUE (type))
     tmin = lower_bound_in_type (type, type);
   else