Add an optimisation for Iop_Left64.

git-svn-id: svn://svn.valgrind.org/vex/trunk@2747

diff --git a/VEX/priv/ir_opt.c b/VEX/priv/ir_opt.c
index f368ce5e3846cde65cd128813573b041750a5670..5982495e9441b635905afdb4c2735e9388ed336e 100644 (file)
--- a/VEX/priv/ir_opt.c
+++ b/VEX/priv/ir_opt.c
@@ -5065,6 +5065,11 @@ static IRExpr* fold_IRExpr_Unop ( IROp op, IRExpr* aa )
       if (is_Unop(aa, Iop_Left32))
          return IRExpr_Unop( Iop_Left32, aa->Iex.Unop.arg );
       break;
+   case Iop_Left64:
+      /* Left64( Left64(x) ) --> Left64(x) */
+      if (is_Unop(aa, Iop_Left64))
+         return IRExpr_Unop( Iop_Left64, aa->Iex.Unop.arg );
+      break;
    case Iop_32to1:
       /* 32to1( 1Uto32 ( x ) ) --> x */
       if (is_Unop(aa, Iop_1Uto32))