(store_field): If storing a record on big endian targets,

set up so we store the high-order bits.
(expand_expr, case COMPONENT_REF): Likewise for loads.

From-SVN: r12714

diff --git a/gcc/expr.c b/gcc/expr.c
index e1b178779f5e8341b735a0dbf3d031627dd9d016..5713d6d2eac93b1af33f952bd1ce0237b4394b0f 100644 (file)
--- a/gcc/expr.c
+++ b/gcc/expr.c
@@ -4105,6 +4105,18 @@ store_field (target, bitsize, bitpos, mode, exp, value_mode,
     {
       rtx 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
+        low-order bits.  However, if EXP's type is a record and this is
+        big-endian machine, we want the upper BITSIZE bits.  */
+      if (BYTES_BIG_ENDIAN && GET_MODE_CLASS (GET_MODE (temp)) == MODE_INT
+         && bitsize < GET_MODE_BITSIZE (GET_MODE (temp))
+         && TREE_CODE (TREE_TYPE (exp)) == RECORD_TYPE)
+       temp = expand_shift (RSHIFT_EXPR, GET_MODE (temp), temp,
+                            size_int (GET_MODE_BITSIZE (GET_MODE (temp))
+                                      - bitsize),
+                            temp, 1);
+
       /* Unless MODE is VOIDmode or BLKmode, convert TEMP to
         MODE.  */
       if (mode != VOIDmode && mode != BLKmode
@@ -5595,6 +5607,18 @@ expand_expr (exp, target, tmode, modifier)
                                     unsignedp, target, ext_mode, ext_mode,
                                     alignment,
                                     int_size_in_bytes (TREE_TYPE (tem)));
+
+           /* If the result is a record type and BITSIZE is narrower than
+              the mode of OP0, an integral mode, and this is a big endian
+              machine, we must put the field into the high-order bits.  */
+           if (TREE_CODE (type) == RECORD_TYPE && BYTES_BIG_ENDIAN
+               && GET_MODE_CLASS (GET_MODE (op0)) == MODE_INT
+               && bitsize < GET_MODE_BITSIZE (GET_MODE (op0)))
+             op0 = expand_shift (LSHIFT_EXPR, GET_MODE (op0), op0,
+                                 size_int (GET_MODE_BITSIZE (GET_MODE (op0))
+                                           - bitsize),
+                                 op0, 1);
+
            if (mode == BLKmode)
              {
                rtx new = assign_stack_temp (ext_mode,