Merge in trunk.

[thirdparty/gcc.git] / gcc / expmed.c

diff --git a/gcc/expmed.c b/gcc/expmed.c
index 90aa45e09e10b4812416300eb9e699a98cc7b254..f7303c9eab4dd4a60351d2296174d93b14bbe883 100644 (file)
--- a/gcc/expmed.c
+++ b/gcc/expmed.c
@@ -636,13 +636,28 @@ store_bit_field_1 (rtx str_rtx, unsigned HOST_WIDE_INT bitsize,
          || (bitsize % BITS_PER_WORD == 0 && bitnum % BITS_PER_WORD == 0)))
     {
       /* Use the subreg machinery either to narrow OP0 to the required
-        words or to cope with mode punning between equal-sized modes.  */
-      rtx sub = simplify_gen_subreg (fieldmode, op0, GET_MODE (op0),
-                                    bitnum / BITS_PER_UNIT);
-      if (sub)
+        words or to cope with mode punning between equal-sized modes.
+        In the latter case, use subreg on the rhs side, not lhs.  */
+      rtx sub;
+
+      if (bitsize == GET_MODE_BITSIZE (GET_MODE (op0)))
        {
-         emit_move_insn (sub, value);
-         return true;
+         sub = simplify_gen_subreg (GET_MODE (op0), value, fieldmode, 0);
+         if (sub)
+           {
+             emit_move_insn (op0, sub);
+             return true;
+           }
+       }
+      else
+       {
+         sub = simplify_gen_subreg (fieldmode, op0, GET_MODE (op0),
+                                    bitnum / BITS_PER_UNIT);
+         if (sub)
+           {
+             emit_move_insn (sub, value);
+             return true;
+           }
        }
     }