(store_field): Support BLKmode bitfield if aligned on byte boundary using emit_block_...

(store_field): Support BLKmode bitfield if aligned on byte boundary using
emit_block_move.
(expand_expr, case COMPONENT_REF): Likewise.

From-SVN: r11971

diff --git a/gcc/expr.c b/gcc/expr.c
index 6678d30..87305aa 100644 (file)
--- a/gcc/expr.c
+++ b/gcc/expr.c
@@ -3915,6 +3915,27 @@ store_field (target, bitsize, bitpos, mode, exp, value_mode,
          && mode != TYPE_MODE (TREE_TYPE (exp)))
        temp = convert_modes (mode, TYPE_MODE (TREE_TYPE (exp)), temp, 1);
 
+      /* If the modes of TARGET and TEMP are both BLKmode, both
+        must be in memory and BITPOS must be aligned on a byte
+        boundary.  If so, we simply do a block copy.  */
+      if (GET_MODE (target) == BLKmode && GET_MODE (temp) == BLKmode)
+       {
+         if (GET_CODE (target) != MEM || GET_CODE (temp) != MEM
+             || bitpos % BITS_PER_UNIT != 0)
+           abort ();
+
+         temp = change_address (temp, VOIDmode,
+                                plus_constant (XEXP (temp, 0),
+                                               bitpos / BITS_PER_UNIT));
+
+         emit_block_move (target, temp,
+                          GEN_INT ((bitsize + BITS_PER_UNIT - 1)
+                                   / BITS_PER_UNIT),
+                          1);
+
+         return value_mode == VOIDmode ? const0_rtx : target;
+       }
+
       /* Store the value in the bitfield.  */
       store_bit_field (target, bitsize, bitpos, mode, temp, align, total_size);
       if (value_mode != VOIDmode)
@@ -5350,7 +5371,27 @@ expand_expr (exp, target, tmode, modifier)
              ext_mode = mode_for_size (bitsize, MODE_INT, 1);
 
            if (ext_mode == BLKmode)
-             abort ();
+             {
+               /* In this case, BITPOS must start at a byte boundary and
+                  TARGET, if specified, must be a MEM.  */
+               if (GET_CODE (op0) != MEM
+                   || (target != 0 && GET_CODE (target) != MEM)
+                   || bitpos % BITS_PER_UNIT != 0)
+                 abort ();
+
+               op0 = change_address (op0, VOIDmode,
+                                     plus_constant (XEXP (op0, 0),
+                                                    bitpos / BITS_PER_UNIT));
+               if (target == 0)
+                 target = assign_temp (type, 0, 1, 1);
+
+               emit_block_move (target, op0,
+                                GEN_INT ((bitsize + BITS_PER_UNIT - 1)
+                                         / BITS_PER_UNIT),
+                                1);
+               
+               return target;
+             }
 
            op0 = validize_mem (op0);