diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 521a44a8340..165751244a8 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,8 @@
+2003-09-06  Zdenek Dvorak  <rakdver@atrey.karlin.mff.cuni.cz>
+
+	* gcse.c (expr_equiv_p): Don't consider anything to be equal to
+	volatile mem.
+
 2003-09-06  Kaveh R. Ghazi  <ghazi@caip.rutgers.edu>
 
 	* ggc-common.c (init_ggc_heuristics): Don't use the heuristics
diff --git a/gcc/gcse.c b/gcc/gcse.c
index 97796637e54..edc8a625746 100644
--- a/gcc/gcse.c
+++ b/gcc/gcse.c
@@ -1787,6 +1787,10 @@ expr_equiv_p (rtx x, rtx y)
 	 due to it being set with the different alias set.  */
       if (MEM_ALIAS_SET (x) != MEM_ALIAS_SET (y))
 	return 0;
+
+      /* A volatile mem should not be considered equivalent to any other.  */
+      if (MEM_VOLATILE_P (x) || MEM_VOLATILE_P (y))
+	return 0;
       break;
 
     /*  For commutative operations, check both orders.  */