gcc: Fix volatile access issue for ARM

[YOCTO #1130]

This patch brings in a patch from gcc for the following issue:

http://gcc.gnu.org/ml/gcc-patches/2011-03/msg01477.html

(From OE-Core rev: 347c30801b6f935a6aefa5578d723a8afcf52790)

Signed-off-by: Saul Wold <sgw@linux.intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

1 files changed, 28 insertions, 0 deletions

diff --git a/meta/recipes-devtools/gcc/gcc-4.6.0/volatile_access_backport.patch b/meta/recipes-devtools/gcc/gcc-4.6.0/volatile_access_backport.patch
new file mode 100644
index 0000000000..9c8681728d
--- /dev/null
+++ b/meta/recipes-devtools/gcc/gcc-4.6.0/volatile_access_backport.patch
@@ -0,0 +1,28 @@
+Pulled from http://gcc.gnu.org/ml/gcc-patches/2011-03/msg01477.html
+
+Upstream-Status: Backport
+
+Signed-off-by: Saul Wold <sgw@linux.intel.com>
+
+    gcc/
+    * expr.c (expand_expr_real_1): Only use BLKmode for volatile
+    accesses which are not naturally aligned.
+
+Index: gcc-4.6.0/gcc/expr.c
+===================================================================
+--- gcc-4.6.0.orig/gcc/expr.c   2011-06-01 15:28:55.000000000 -0700
++++ gcc-4.6.0/gcc/expr.c        2011-06-01 15:41:17.154848182 -0700
+@@ -9178,8 +9178,11 @@
+                && modifier != EXPAND_CONST_ADDRESS
+                && modifier != EXPAND_INITIALIZER)
+            /* If the field is volatile, we always want an aligned
+-              access.  */
+-           || (volatilep && flag_strict_volatile_bitfields > 0)
++              access.  Only do this if the access is not already naturally
++              aligned, otherwise "normal" (non-bitfield) volatile fields
++              become non-addressable.  */
++           || (volatilep && flag_strict_volatile_bitfields > 0
++               && (bitpos % GET_MODE_ALIGNMENT (mode) != 0))
+            /* If the field isn't aligned enough to fetch as a memref,
+               fetch it as a bit field.  */
+            || (mode1 != BLKmode