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

1 files changed, 9 insertions, 0 deletions

diff --git a/gcc/gcse.c b/gcc/gcse.c
index d660a49..f43f382 100644
--- a/gcc/gcse.c
+++ b/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: