gcse.c (hash_expr_1): Add in MEM_ALIAS_SET.

        * gcse.c (hash_expr_1): Add in MEM_ALIAS_SET.
        (expr_equiv_p): Reject memories with different alias sets.

From-SVN: r30039

gcc/ChangeLog

+Sat Oct 16 00:07:01 1999  Richard Henderson  <rth@cygnus.com>
+
+	* gcse.c (hash_expr_1): Add in MEM_ALIAS_SET.
+	(expr_equiv_p): Reject memories with different alias sets.
+
 Fri Oct 15 15:17:29 1999  Greg McGary  <gkm@gnu.org>
 
 	* flags.h (flag_bounds_check, flag_bounded_pointers): New extern decls.

gcc/gcse.c

@@ -1446,6 +1446,7 @@ hash_expr_1 (x, mode, do_not_record_p)
 	  return 0;
 	}
       hash += (unsigned) MEM;
+      hash += MEM_ALIAS_SET (x);
       x = XEXP (x, 0);
       goto repeat;
 
@@ -1578,6 +1579,14 @@ expr_equiv_p (x, y)
     case REG:
       return REGNO (x) == REGNO (y);
 
+    case MEM:
+      /* Can't merge two expressions in different alias sets, since we can
+	 decide that the expression is transparent in a block when it isn't,
+	 due to it being set with the different alias set.  */
+      if (MEM_ALIAS_SET (x) != MEM_ALIAS_SET (y))
+	return 0;
+      break;
+
     /*  For commutative operations, check both orders.  */
     case PLUS:
     case MULT: