diff --git a/emit-rtl.c b/emit-rtl.c
index 9600f2f..4434801 100644
--- a/emit-rtl.c
+++ b/emit-rtl.c
@@ -3352,7 +3352,8 @@ init_emit_once (line_numbers)
 	  bzero ((char *) &u, sizeof u);  /* Zero any holes in a structure.  */
 	  u.d = i == 0 ? dconst0 : i == 1 ? dconst1 : dconst2;
 
-	  bcopy ((char *) &u, (char *) &CONST_DOUBLE_LOW (tem), sizeof u);
+	  bcopy ((char *) &u, (char *) &CONST_DOUBLE_LOW (tem), sizeof u / 2);
+	  bcopy ((char *) &u + (sizeof u / 2), (char *) &CONST_DOUBLE_HIGH (tem), sizeof u / 2);
 	  CONST_DOUBLE_MEM (tem) = cc0_rtx;
 	  PUT_MODE (tem, mode);