1 files changed, 117 insertions, 0 deletions

diff --git a/meta/recipes-devtools/gcc/gcc-4.6.0/gcc-4_6-branch-backports/0288-2011-05-20-Richard-Guenther-rguenther-suse.de.patch b/meta/recipes-devtools/gcc/gcc-4.6.0/gcc-4_6-branch-backports/0288-2011-05-20-Richard-Guenther-rguenther-suse.de.patch
new file mode 100644
index 0000000000..ff2cb06641
--- /dev/null
+++ b/meta/recipes-devtools/gcc/gcc-4.6.0/gcc-4_6-branch-backports/0288-2011-05-20-Richard-Guenther-rguenther-suse.de.patch
@@ -0,0 +1,117 @@
+From 24f5b59f5c9418d39087b36dd0d275f71ac4dca5 Mon Sep 17 00:00:00 2001
+From: rguenth <rguenth@138bc75d-0d04-0410-961f-82ee72b054a4>
+Date: Fri, 20 May 2011 15:08:56 +0000
+Subject: [PATCH] 2011-05-20  Richard Guenther  <rguenther@suse.de>
+
+        PR tree-optimization/49079
+        * tree-dfa.c (get_ref_base_and_extent): Handle view-converting
+        MEM_REFs correctly for the trailing array access detection.
+        Special case constants the same way as decls for overall size
+        constraining.
+
+        * gcc.dg/torture/pr49079.c: New testcase.
+
+
+git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/branches/gcc-4_6-branch@173955 138bc75d-0d04-0410-961f-82ee72b054a4
+
+index 0efa0eb..dcb39c1 100644
+new file mode 100644
+index 0000000..1b53d3c
+--- /dev/null
++++ b/gcc/testsuite/gcc.dg/torture/pr49079.c
+@@ -0,0 +1,31 @@
++/* { dg-do run } */
++
++extern void abort (void);
++
++struct Ustr
++{
++  unsigned char data[1];
++};
++
++static unsigned int
++ustr_xi__embed_val_get(const unsigned char *data)
++{
++  return (unsigned int)data[0];
++}
++
++int __attribute__((noinline)) zero(void) { return 0; }
++
++static unsigned int
++ustr_len(const struct Ustr *s1)
++{
++  return ustr_xi__embed_val_get(s1->data + 1 + zero());
++}
++
++int
++main()
++{
++  if (ustr_len (((struct Ustr *) "\x01" "\x0002" "s2")) != 2)
++    abort ();
++
++  return 0;
++}
+diff --git a/gcc/tree-dfa.c b/gcc/tree-dfa.c
+index 6490c5e..2dacd44 100644
+--- a/gcc/tree-dfa.c
++++ b/gcc/tree-dfa.c
+@@ -709,6 +709,7 @@ get_ref_base_and_extent (tree exp, HOST_WIDE_INT *poffset,
+   tree size_tree = NULL_TREE;
+   HOST_WIDE_INT bit_offset = 0;
+   bool seen_variable_array_ref = false;
++  tree base_type;
+ 
+   /* First get the final access size from just the outermost expression.  */
+   if (TREE_CODE (exp) == COMPONENT_REF)
+@@ -739,6 +740,8 @@ get_ref_base_and_extent (tree exp, HOST_WIDE_INT *poffset,
+      and find the ultimate containing object.  */
+   while (1)
+     {
++      base_type = TREE_TYPE (exp);
++
+       switch (TREE_CODE (exp))
+        {
+        case BIT_FIELD_REF:
+@@ -926,9 +929,16 @@ get_ref_base_and_extent (tree exp, HOST_WIDE_INT *poffset,
+      the array.  The simplest way to conservatively deal with this
+      is to punt in the case that offset + maxsize reaches the
+      base type boundary.  This needs to include possible trailing padding
+-     that is there for alignment purposes.
++     that is there for alignment purposes.  */
++
++  if (seen_variable_array_ref
++      && maxsize != -1
++      && (!host_integerp (TYPE_SIZE (base_type), 1)
++         || (bit_offset + maxsize
++             == (signed) TREE_INT_CST_LOW (TYPE_SIZE (base_type)))))
++    maxsize = -1;
+ 
+-     That is of course only true if the base object is not a decl.  */
++  /* In case of a decl or constant base object we can do better.  */
+ 
+   if (DECL_P (exp))
+     {
+@@ -938,12 +948,14 @@ get_ref_base_and_extent (tree exp, HOST_WIDE_INT *poffset,
+          && host_integerp (DECL_SIZE (exp), 1))
+        maxsize = TREE_INT_CST_LOW (DECL_SIZE (exp)) - bit_offset;
+     }
+-  else if (seen_variable_array_ref
+-          && maxsize != -1
+-          && (!host_integerp (TYPE_SIZE (TREE_TYPE (exp)), 1)
+-              || (bit_offset + maxsize
+-                  == (signed) TREE_INT_CST_LOW (TYPE_SIZE (TREE_TYPE (exp))))))
+-    maxsize = -1;
++  else if (CONSTANT_CLASS_P (exp))
++    {
++      /* If maxsize is unknown adjust it according to the size of the
++         base type constant.  */
++      if (maxsize == -1
++         && host_integerp (TYPE_SIZE (TREE_TYPE (exp)), 1))
++       maxsize = TREE_INT_CST_LOW (TYPE_SIZE (TREE_TYPE (exp))) - bit_offset;
++    }
+ 
+   /* ???  Due to negative offsets in ARRAY_REF we can end up with
+      negative bit_offset here.  We might want to store a zero offset
+-- 
+1.7.0.4
+