Fixed: #2270 AS3 decompilation - unnnecessary local registers assignments as part of expressions when using optimization like dup, setlocal N instead of setlocal N, getlocal N

libsrc/ffdec_lib/testdata/as3_assembled/abc/as3_assembled-0/as3_assembled-0.main.asasm

@@ -34,5 +34,6 @@ program
  #include "tests/TestMutatingSwitch.script.asasm"
  #include "tests/TestSwitchMostCommon.script.asasm"
  #include "tests/TestXmlStar.script.asasm"
+ #include "tests/TestLocalRegIf.script.asasm"
  ; place to add next
 end ; program

libsrc/ffdec_lib/testdata/as3_assembled/abc/as3_assembled-0/tests/TestLocalRegIf.class.asasm

@@ -0,0 +1,80 @@
+class
+ refid "tests:TestLocalRegIf"
+ instance QName(PackageNamespace("tests"), "TestLocalRegIf")
+  extends QName(PackageNamespace(""), "Object")
+  flag SEALED
+  flag PROTECTEDNS
+  protectedns ProtectedNamespace("tests:TestLocalRegIf")
+  iinit
+   refid "tests:TestLocalRegIf/instance/init"
+   body
+    maxstack 1
+    localcount 1
+    initscopedepth 4
+    maxscopedepth 5
+    code
+     getlocal0
+     pushscope
+
+     getlocal0
+     constructsuper      0
+
+     returnvoid
+    end ; code
+   end ; body
+  end ; method
+  trait method QName(PackageNamespace(""), "run")
+   method
+    refid "tests:TestLocalRegIf/instance/run"
+    returns QName(PackageNamespace(""), "void")
+    body
+     maxstack 2
+     localcount 7
+     initscopedepth 4
+     maxscopedepth 5
+     code
+            getlocal0
+            pushscope
+            pushbyte 8
+            dup
+            setlocal1
+            pushbyte 5
+            greaterthan
+            dup
+            iffalse ofs0020
+            pop
+            getlocal1
+            pushbyte 10
+            lessthan
+   ofs0020:
+            iffalse ofs0030
+            getlex QName(PackageNamespace(""),"trace")
+            getglobalscope
+            pushstring "I"
+            call 1
+            pop
+   ofs0030:
+            returnvoid
+      
+      returnvoid
+     end ; code
+    end ; body
+   end ; method
+  end ; trait
+ end ; instance
+ cinit
+  refid "tests:TestLocalRegIf/class/init"
+  body
+   maxstack 1
+   localcount 1
+   initscopedepth 3
+   maxscopedepth 4
+   code
+    getlocal0
+    pushscope
+
+    returnvoid
+   end ; code
+  end ; body
+ end ; method
+end ; class

libsrc/ffdec_lib/testdata/as3_assembled/abc/as3_assembled-0/tests/TestLocalRegIf.script.asasm

@@ -0,0 +1,29 @@
+script
+ sinit
+  refid "tests:TestLocalRegIf/init"
+  body
+   maxstack 2
+   localcount 1
+   initscopedepth 1
+   maxscopedepth 3
+   code
+    getlocal0
+    pushscope
+
+    findpropstrict      Multiname("TestLocalRegIf", [PackageNamespace("tests")])
+    getlex              QName(PackageNamespace(""), "Object")
+    pushscope
+
+    getlex              Multiname("Object", [PrivateNamespace(null, "tests:TestLocalRegIf"), PackageNamespace(""), PackageNamespace("tests"), PackageInternalNs("tests"), Namespace("http://adobe.com/AS3/2006/builtin")])
+    newclass            "tests:TestLocalRegIf"
+    popscope
+    initproperty        QName(PackageNamespace("tests"), "TestLocalRegIf")
+
+    returnvoid
+   end ; code
+  end ; body
+ end ; method
+ trait class QName(PackageNamespace("tests"), "TestLocalRegIf")
+  #include "TestLocalRegIf.class.asasm"
+ end ; trait
+end ; script

libsrc/ffdec_lib/testdata/as3_new/build_air_debug.bat

@@ -2,4 +2,6 @@
 set COMPILERKIND=air
 set SWFNAME=as3_new
 call c:\air\bin\mxmlc.bat -debug=true -output bin/%SWFNAME%.%COMPILERKIND%.swf src/Main.as 1> buildlog.%COMPILERKIND%.txt 2>&1
-rem -warnings=false
+rem set COMPILERKIND=air.optimize
+rem call c:\air\bin\mxmlc.bat -compiler.optimize -output bin/%SWFNAME%.%COMPILERKIND%.swf src/Main.as 1> buildlog.%COMPILERKIND%.txt 2>&1
+rem -warnings=false

libsrc/ffdec_lib/testdata/as3_new/build_flex_debug.bat

@@ -2,4 +2,6 @@
 set COMPILERKIND=flex
 set SWFNAME=as3_new
 call c:\flex\bin\mxmlc.bat -debug=true -output bin/%SWFNAME%.%COMPILERKIND%.swf src/Main.as 1> buildlog.%COMPILERKIND%.txt 2>&1
+rem set COMPILERKIND=flex.optimize
+rem call c:\flex\bin\mxmlc.bat -compiler.optimize -output bin/%SWFNAME%.%COMPILERKIND%.swf src/Main.as 1> buildlog.%COMPILERKIND%.txt 2>&1
 rem -warnings=false

libsrc/ffdec_lib/testdata/as3_new/src/Main.as

@@ -97,6 +97,7 @@ package
         TestNegate;
         TestNumberCall;
         TestOperations;
+        TestOptimization;
         TestOptionalParameters;
         TestParamNames;
         TestParamsCount;

libsrc/ffdec_lib/testdata/as3_new/src/tests/TestHello.as

@@ -5,7 +5,7 @@ package tests
 	{
 		public function run():*
 		{
-			trace("hello");         
+			trace("hello");              
 		}
 	}
 }

libsrc/ffdec_lib/testdata/as3_new/src/tests/TestOptimization.as

@@ -0,0 +1,25 @@
+package tests
+{
+	
+	public class TestOptimization
+	{
+		public function run():*
+		{
+            // Add more than 3 variables. 
+            // Optimization happens from register 4 on.
+            // (setlocal X takes more bytes than dup)
+			var a:int = 1;
+            var b:int = 2;
+            var c:int = 3;
+            
+            var d:int = 4; //setlocal N
+            var e:int = d + 5; //getlocal N is replaced with dup before setlocal N
+            
+            //We must leave this case intact:
+            var f:int;
+            var g:int;
+            var h:int;
+            var i:int = h = g = f;   
+		}
+	}
+}