For real this time...

        PR middle-end/18008
        * c-decl.c (finish_struct): Set DECL_MODE after resetting a
        field's type.
        * expr.c (store_field): Strip conversions to odd-bit-sized types
        if the destination field width matches.

git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@94294 138bc75d-0d04-0410-961f-82ee72b054a4

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 2885274..3f15855 100644 (file)
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,5 +1,13 @@
 2005-01-26  Richard Henderson  <rth@redhat.com>
 
+       PR middle-end/18008
+       * c-decl.c (finish_struct): Set DECL_MODE after resetting a
+       field's type.
+       * expr.c (store_field): Strip conversions to odd-bit-sized types
+       if the destination field width matches.
+
+2005-01-26  Richard Henderson  <rth@redhat.com>
+
        * c-decl.c, expmed.c, expr.c: Revert last change.
 
 2005-01-26  Richard Henderson  <rth@redhat.com>

diff --git a/gcc/c-decl.c b/gcc/c-decl.c
index 6673927..61521e8 100644 (file)
--- a/gcc/c-decl.c
+++ b/gcc/c-decl.c
@@ -5301,8 +5301,11 @@ finish_struct (tree t, tree fieldlist, tree attributes)
            = tree_low_cst (DECL_INITIAL (*fieldlistp), 1);
          tree type = TREE_TYPE (*fieldlistp);
          if (width != TYPE_PRECISION (type))
-           TREE_TYPE (*fieldlistp)
-             = build_nonstandard_integer_type (width, TYPE_UNSIGNED (type));
+           {
+             TREE_TYPE (*fieldlistp)
+               = build_nonstandard_integer_type (width, TYPE_UNSIGNED (type));
+             DECL_MODE (*fieldlistp) = TYPE_MODE (TREE_TYPE (*fieldlistp));
+           }
          DECL_INITIAL (*fieldlistp) = 0;
        }
       else

diff --git a/gcc/expr.c b/gcc/expr.c
index ed693a3..1f82b1d 100644 (file)
--- a/gcc/expr.c
+++ b/gcc/expr.c
@@ -5215,7 +5215,21 @@ store_field (rtx target, HOST_WIDE_INT bitsize, HOST_WIDE_INT bitpos,
          && TREE_CODE (TYPE_SIZE (TREE_TYPE (exp))) == INTEGER_CST
          && compare_tree_int (TYPE_SIZE (TREE_TYPE (exp)), bitsize) != 0))
     {
-      rtx temp = expand_expr (exp, NULL_RTX, VOIDmode, 0);
+      rtx temp;
+
+      /* If EXP is a NOP_EXPR of precision less than its mode, then that
+        implies a mask operation.  If the precision is the same size as
+        the field we're storing into, that mask is redundant.  This is
+        particularly common with bit field assignments generated by the
+        C front end.  */
+      if (TREE_CODE (exp) == NOP_EXPR
+         && INTEGRAL_TYPE_P (TREE_TYPE (exp))
+         && (TYPE_PRECISION (TREE_TYPE (exp))
+             < GET_MODE_BITSIZE (TYPE_MODE (TREE_TYPE (exp))))
+         && bitsize == TYPE_PRECISION (TREE_TYPE (exp)))
+       exp = TREE_OPERAND (exp, 0);
+
+      temp = expand_expr (exp, NULL_RTX, VOIDmode, 0);
 
       /* If BITSIZE is narrower than the size of the type of EXP
         we will be narrowing TEMP.  Normally, what's wanted are the