[Valgrind-developers] vex: r3094 - /trunk/priv/ir_opt.c

[<sv...@va...>]

Author: sewardj
Date: Fri Feb 27 12:51:22 2015
New Revision: 3094

Log:
fold_Expr: add rules
   Xor8/16/32/64(0,t) ==> t
   Xor8/16/32/64(t,0) ==> t

Modified:
    trunk/priv/ir_opt.c

Modified: trunk/priv/ir_opt.c
==============================================================================
--- trunk/priv/ir_opt.c (original)
+++ trunk/priv/ir_opt.c Fri Feb 27 12:51:22 2015
@@ -2292,6 +2292,17 @@
                   //   e2 = e->Iex.Binop.arg2;
                   //   break;
                   //}
+               } else {
+                  /* Xor8/16/32/64(0,t) ==> t */
+                  if (isZeroU(e->Iex.Binop.arg1)) {
+                     e2 = e->Iex.Binop.arg2;
+                     break;
+                  }
+                  /* Xor8/16/32/64(t,0) ==> t */
+                  if (isZeroU(e->Iex.Binop.arg2)) {
+                     e2 = e->Iex.Binop.arg1;
+                     break;
+                  }
                }
                break;