From: Julian Seward <jseward@acm.org>
Date: Thu, 21 Apr 2005 01:35:48 +0000 (+0000)
Subject: Add an identity, Or8(x,0) --> x.
X-Git-Tag: svn/VALGRIND_3_0_1^2~201
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=853a2de0ae165f49bf0b043a583275628a0ab4d0;p=thirdparty%2Fvalgrind.git

Add an identity, Or8(x,0) --> x.


git-svn-id: svn://svn.valgrind.org/vex/trunk@1133
---

diff --git a/VEX/priv/ir/iropt.c b/VEX/priv/ir/iropt.c
index 724b8036e6..2f5769de82 100644
--- a/VEX/priv/ir/iropt.c
+++ b/VEX/priv/ir/iropt.c
@@ -1228,6 +1228,13 @@ static IRExpr* fold_Expr ( IRExpr* e )
             e2 = e->Iex.Binop.arg1;
          } else
 
+         /* Or8(x,0) ==> x */
+         if ((e->Iex.Binop.op == Iop_Or8)
+             && e->Iex.Binop.arg2->tag == Iex_Const
+             && e->Iex.Binop.arg2->Iex.Const.con->Ico.U8 == 0) {
+            e2 = e->Iex.Binop.arg1;
+         } else
+
          /* Or32/Add32(x,0) ==> x */
          if ((e->Iex.Binop.op == Iop_Add32 || e->Iex.Binop.op == Iop_Or32)
              && e->Iex.Binop.arg2->tag == Iex_Const