gcc: upstream alignment cleanups.

This solves GCC/32617 and contributes to reduce differences with
Apple's gcc42.

Complete some references in the ChangeLog while here.

Obtained from:	gcc 4.3 (rev. 126529, 126588; GPLv2)
MFC after:	3 weeks

1 files changed, 14 insertions, 22 deletions

diff --git a/contrib/gcc/tree.h b/contrib/gcc/tree.h
index c502182eba39..6cfc3d375ccb 100644
--- a/contrib/gcc/tree.h
+++ b/contrib/gcc/tree.h
@@ -2426,13 +2426,11 @@ struct tree_struct_field_tag GTY(())
 /* Likewise for the size in bytes.  */
 #define DECL_SIZE_UNIT(NODE) (DECL_COMMON_CHECK (NODE)->decl_common.size_unit)
 /* Holds the alignment required for the datum, in bits.  */
-#define DECL_ALIGN(NODE) (DECL_COMMON_CHECK (NODE)->decl_common.u1.a.align)
+#define DECL_ALIGN(NODE) (DECL_COMMON_CHECK (NODE)->decl_common.align)
 /* The alignment of NODE, in bytes.  */
 #define DECL_ALIGN_UNIT(NODE) (DECL_ALIGN (NODE) / BITS_PER_UNIT)
-/* For FIELD_DECLs, off_align holds the number of low-order bits of
-   DECL_FIELD_OFFSET which are known to be always zero.
-   DECL_OFFSET_ALIGN thus returns the alignment that DECL_FIELD_OFFSET
-   has.  */
+/* Set if the alignment of this DECL has been set by the user, for
+   example with an 'aligned' attribute.  */
 #define DECL_USER_ALIGN(NODE) (DECL_COMMON_CHECK (NODE)->decl_common.user_align)
 /* Holds the machine mode corresponding to the declaration of a variable or
    field.  Always equal to TYPE_MODE (TREE_TYPE (decl)) except for a
@@ -2443,7 +2441,8 @@ struct tree_struct_field_tag GTY(())
    operation it is.  Note, however, that this field is overloaded, with
    DECL_BUILT_IN_CLASS as the discriminant, so the latter must always be
    checked before any access to the former.  */
-#define DECL_FUNCTION_CODE(NODE) (FUNCTION_DECL_CHECK (NODE)->decl_common.u1.f)
+#define DECL_FUNCTION_CODE(NODE) \
+  (FUNCTION_DECL_CHECK (NODE)->function_decl.function_code)
 #define DECL_DEBUG_EXPR_IS_FROM(NODE) \
   (DECL_COMMON_CHECK (NODE)->decl_common.debug_expr_is_from)
 
@@ -2581,20 +2580,9 @@ struct tree_decl_common GTY(())
   unsigned gimple_reg_flag : 1;
   unsigned call_clobbered_flag : 1;
 
-  union tree_decl_u1 {
-    /* In a FUNCTION_DECL for which DECL_BUILT_IN holds, this is
-       DECL_FUNCTION_CODE.  */
-    enum built_in_function f;
-    /* In a FUNCTION_DECL for which DECL_BUILT_IN does not hold, this
-       is used by language-dependent code.  */
-    HOST_WIDE_INT i;
-    /* DECL_ALIGN and DECL_OFFSET_ALIGN.  (These are not used for
-       FUNCTION_DECLs).  */
-    struct tree_decl_u1_a {
-      unsigned int align : 24;
-      unsigned int off_align : 8;
-    } a;
-  } GTY ((skip)) u1;
+  unsigned int align : 24;
+  /* DECL_OFFSET_ALIGN, used only for FIELD_DECLs.  */
+  unsigned int off_align : 8;
 
   tree size_unit;
   tree initial;
@@ -2679,11 +2667,11 @@ struct tree_decl_with_rtl GTY(())
    DECL_OFFSET_ALIGN thus returns the alignment that DECL_FIELD_OFFSET
    has.  */
 #define DECL_OFFSET_ALIGN(NODE) \
-  (((unsigned HOST_WIDE_INT)1) << FIELD_DECL_CHECK (NODE)->decl_common.u1.a.off_align)
+  (((unsigned HOST_WIDE_INT)1) << FIELD_DECL_CHECK (NODE)->decl_common.off_align)
 
 /* Specify that DECL_ALIGN(NODE) is a multiple of X.  */
 #define SET_DECL_OFFSET_ALIGN(NODE, X) \
-  (FIELD_DECL_CHECK (NODE)->decl_common.u1.a.off_align = exact_log2 ((X) & -(X)))
+  (FIELD_DECL_CHECK (NODE)->decl_common.off_align = exact_log2 ((X) & -(X)))
 /* 1 if the alignment for this type was requested by "aligned" attribute,
    0 if it is the default for this type.  */
 
@@ -3096,6 +3084,10 @@ struct tree_function_decl GTY(())
 {
   struct tree_decl_non_common common;
 
+  /* In a FUNCTION_DECL for which DECL_BUILT_IN holds, this is
+     DECL_FUNCTION_CODE.  Otherwise unused.  */
+  enum built_in_function function_code;
+
   unsigned static_ctor_flag : 1;
   unsigned static_dtor_flag : 1;
   unsigned uninlinable : 1;