From: Florian Krohm <florian@eich-krohm.de>
Date: Fri, 18 Jul 2014 21:23:46 +0000 (+0000)
Subject: Add a few more algebraic optimisations for Iop_And8/16.
X-Git-Tag: svn/VALGRIND_3_10_1^2~66
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=2e9c50e008a8da8d1a2df5c500d34d5f7bb0d747;p=thirdparty%2Fvalgrind.git

Add a few more algebraic optimisations for Iop_And8/16.
Observed on s390.


git-svn-id: svn://svn.valgrind.org/vex/trunk@2905
---

diff --git a/VEX/priv/ir_opt.c b/VEX/priv/ir_opt.c
index d1fe9ad20c..bc019dad6d 100644
--- a/VEX/priv/ir_opt.c
+++ b/VEX/priv/ir_opt.c
@@ -2163,32 +2163,37 @@ static IRExpr* fold_Expr ( IRExpr** env, IRExpr* e )
                }
                break;
 
-            case Iop_And64:
+            case Iop_And8:
+            case Iop_And16:
             case Iop_And32:
-               /* And32/And64(x,1---1b) ==> x */
+            case Iop_And64:
+               /* And8/And16/And32/And64(x,1---1b) ==> x */
                if (isOnesU(e->Iex.Binop.arg2)) {
                   e2 = e->Iex.Binop.arg1;
                   break;
                }
-               /* And32/And64(x,0) ==> 0 */
+               /* And8/And16/And32/And64(1---1b,x) ==> x */
+               if (isOnesU(e->Iex.Binop.arg1)) {
+                  e2 = e->Iex.Binop.arg2;
+                  break;
+               }
+               /* And8/And16/And32/And64(x,0) ==> 0 */
                if (isZeroU(e->Iex.Binop.arg2)) {
                   e2 = e->Iex.Binop.arg2;
                   break;
                }
-               /* And32/And64(0,x) ==> 0 */
+               /* And8/And16/And32/And64(0,x) ==> 0 */
                if (isZeroU(e->Iex.Binop.arg1)) {
                   e2 = e->Iex.Binop.arg1;
                   break;
                }
-               /* And32/And64(t,t) ==> t, for some IRTemp t */
+               /* And8/And16/And32/And64(t,t) ==> t, for some IRTemp t */
                if (sameIRExprs(env, e->Iex.Binop.arg1, e->Iex.Binop.arg2)) {
                   e2 = e->Iex.Binop.arg1;
                   break;
                }
                break;
 
-            case Iop_And8:
-            case Iop_And16:
             case Iop_AndV128:
             case Iop_AndV256:
                /* And8/And16/AndV128/AndV256(t,t)