updated
authorChristian Urban <christian.urban@kcl.ac.uk>
Tue, 01 Dec 2020 05:41:12 +0000
changeset 813 059f970287d1
parent 812 2f9a0dcf61ae
child 814 1fbaa5f05516
updated
progs/fun/fun.sc
progs/fun/fun_llvm.sc
progs/fun/funt.sc
progs/fun/jasmin.jar
slides/slides08.pdf
slides/slides08.tex
--- a/progs/fun/fun.sc	Fri Nov 27 13:53:06 2020 +0000
+++ b/progs/fun/fun.sc	Tue Dec 01 05:41:12 2020 +0000
@@ -1,17 +1,25 @@
 // A Small Compiler for a Simple Functional Language
-// (it does not include a parser and lexer)
+// (includes a parser and lexer)
 //
 // call with
 //
+//    amm fun.sc test
+//
+//  or
+//
 //    amm fun.sc main defs.fun
-//
 //    amm fun.sc main fact.fun
 //
-// or
-//    amm fun.sc test
+//  or
+// 
+//    amm fun.sc run defs.fun
+//    amm fun.sc run fact.fun   
 //
-// the latter will print out the JVM instructions for two
+// the first prints out the JVM instructions for two
 // factorial functions
+//
+// the next compile/run fun files
+//
 
 import $file.fun_tokens, fun_tokens._
 import $file.fun_parser, fun_parser._ 
@@ -76,15 +84,21 @@
 // variable / index environments
 type Env = Map[String, Int]
 
+def compile_op(op: String) = op match {
+  case "+" => i"iadd"
+  case "-" => i"isub"
+  case "*" => i"imul"
+  case "/" => i"idiv"
+  case "%" => i"irem"
+}
+
+
 // compile expressions
-def compile_exp(a: Exp, env : Env) : String = a match {
+def compile_exp(a: Exp, env: Env) : String = a match {
   case Num(i) => i"ldc $i"
   case Var(s) => i"iload ${env(s)}"
-  case Aop("+", a1, a2) => compile_exp(a1, env) ++ compile_exp(a2, env) ++ i"iadd"
-  case Aop("-", a1, a2) => compile_exp(a1, env) ++ compile_exp(a2, env) ++ i"isub"
-  case Aop("*", a1, a2) => compile_exp(a1, env) ++ compile_exp(a2, env) ++ i"imul"
-  case Aop("/", a1, a2) => compile_exp(a1, env) ++ compile_exp(a2, env) ++ i"idiv"
-  case Aop("%", a1, a2) => compile_exp(a1, env) ++ compile_exp(a2, env) ++ i"irem"
+  case Aop(op, a1, a2) => 
+    compile_exp(a1, env) ++ compile_exp(a2, env) ++ compile_op(op)
   case If(b, a1, a2) => {
     val if_else = Fresh("If_else")
     val if_end = Fresh("If_end")
@@ -137,8 +151,8 @@
   }
   case Main(a) => {
     m".method public static main([Ljava/lang/String;)V" ++
-    m".limit locals 200" ++
-    m".limit stack 200" ++
+    m".limit locals 1" ++
+    m".limit stack ${1 + max_stack_exp(a)}" ++
     compile_exp(a, Map()) ++
     i"invokestatic XXX/XXX/write(I)V" ++
     i"return" ++
@@ -153,6 +167,21 @@
 }
 
 
+import ammonite.ops._
+
+def compile_to_file(prog: List[Decl], class_name: String) : Unit = 
+  write.over(pwd / s"$class_name.j", compile(prog, class_name))  
+
+def compile_and_run(prog: List[Decl], class_name: String) : Unit = {
+  println(s"Start of compilation")
+  compile_to_file(prog, class_name)
+  println(s"generated $class_name.j file")
+  os.proc("java", "-jar", "jasmin.jar", s"$class_name.j").call()
+  println(s"generated $class_name.class file")
+  println(s"Run program")
+  os.proc("java", s"${class_name}/${class_name}").call(stdout = os.Inherit)
+  println(s"done.")
+}
 
 
 // An example program (two versions of factorial)
@@ -181,9 +210,9 @@
                              Aop("*",Var("n"),Var("acc")))))),
 
        Main(Sequence(Write(Call("fact",List(Num(10)))),
-                 Write(Call("facT",List(Num(10), Num(1)))))))
+                     Write(Call("facT",List(Num(10), Num(1)))))))
 
-// prints out the JVM instructions
+// prints out the JVM instructions for the factorial example
 @main
 def test() = 
   println(compile(test_prog, "fact"))
@@ -197,3 +226,12 @@
     val ast = parse_tks(tks)
     println(compile(ast, class_name))
 }
+
+@main
+def run(fname: String) = {
+    val path = os.pwd / fname
+    val class_name = fname.stripSuffix("." ++ path.ext)
+    val tks = tokenise(os.read(path))
+    val ast = parse_tks(tks)
+    compile_and_run(ast, class_name)
+}
--- a/progs/fun/fun_llvm.sc	Fri Nov 27 13:53:06 2020 +0000
+++ b/progs/fun/fun_llvm.sc	Tue Dec 01 05:41:12 2020 +0000
@@ -1,22 +1,35 @@
 // A Small LLVM Compiler for a Simple Functional Language
 // (includes an external lexer and parser)
 //
+//
 // call with 
 //
+//     amm fun_llvm.sc main fact.fun
+//     amm fun_llvm.sc main defs.fun
+//
+// or
+//
 //     amm fun_llvm.sc write fact.fun
-//
 //     amm fun_llvm.sc write defs.fun
 //
-// this will generate a .ll file. Other options are compile and run.
+//       this will generate an .ll file. 
+//
+// or 
 //
-// You can interpret an .ll file using lli.
+//     amm fun_llvm.sc run fact.fun
+//     amm fun_llvm.sc run defs.fun
+//
+//
+// You can interpret an .ll file using lli, for example
+//
+//      lli fact.ll
 //
 // The optimiser can be invoked as
 //
 //      opt -O1 -S in_file.ll > out_file.ll
 //      opt -O3 -S in_file.ll > out_file.ll
 //
-// The code produced for the various architectures can be obtains with
+// The code produced for the various architectures can be obtain with
 //   
 //   llc -march=x86 -filetype=asm in_file.ll -o -
 //   llc -march=arm -filetype=asm in_file.ll -o -  
@@ -30,7 +43,6 @@
 
 import $file.fun_tokens, fun_tokens._
 import $file.fun_parser, fun_parser._ 
-import scala.util._
 
 
 // for generating new labels
@@ -150,10 +162,11 @@
   case "/" => "sdiv i32 "
   case "%" => "srem i32 "
   case "==" => "icmp eq i32 "
-  case "<=" => "icmp sle i32 "    // signed less or equal
-  case "<" => "icmp slt i32 "     // signed less than
+  case "<=" => "icmp sle i32 "     // signed less or equal
+  case "<"  => "icmp slt i32 "     // signed less than
 }
 
+// compile K values
 def compile_val(v: KVal) : String = v match {
   case KNum(i) => s"$i"
   case KVar(s) => s"%$s"
@@ -211,19 +224,22 @@
   }
 }
 
+
 // main compiler functions
-
-def compile_prog(prog: List[Decl]) : String = 
+def compile(prog: List[Decl]) : String = 
   prelude ++ (prog.map(compile_decl).mkString)
 
 
+import ammonite.ops._
+
+
 @main
-def compile(fname: String) = {
+def main(fname: String) = {
     val path = os.pwd / fname
     val file = fname.stripSuffix("." ++ path.ext)
     val tks = tokenise(os.read(path))
     val ast = parse_tks(tks)
-    println(compile_prog(ast))
+    println(compile(ast))
 }
 
 @main
@@ -232,7 +248,7 @@
     val file = fname.stripSuffix("." ++ path.ext)
     val tks = tokenise(os.read(path))
     val ast = parse_tks(tks)
-    val code = compile_prog(ast)
+    val code = compile(ast)
     os.write.over(os.pwd / (file ++ ".ll"), code)
 }
 
@@ -240,13 +256,11 @@
 def run(fname: String) = {
     val path = os.pwd / fname
     val file = fname.stripSuffix("." ++ path.ext)
-    val tks = tokenise(os.read(path))
-    val ast = parse_tks(tks)
-    val code = compile_prog(ast)
-    os.write.over(os.pwd / (file ++ ".ll"), code)
+    write(fname)  
     os.proc("llc", "-filetype=obj", file ++ ".ll").call()
-    os.proc("gcc", file ++ ".o", "-o", file).call()
-    print(os.proc(os.pwd / file).call().out.string)
+    os.proc("gcc", file ++ ".o", "-o", file ++ ".bin").call()
+    os.proc(os.pwd / (file ++ ".bin")).call(stdout = os.Inherit)
+    println(s"done.")
 }
 
 
--- a/progs/fun/funt.sc	Fri Nov 27 13:53:06 2020 +0000
+++ b/progs/fun/funt.sc	Tue Dec 01 05:41:12 2020 +0000
@@ -1,5 +1,20 @@
 // A Small Compiler for a Simple Functional Language
-// (includes a lexer and a parser)
+//  - includes a lexer and a parser
+//  - performs tail-call optimisations
+//
+// call with
+//
+//    amm fun.sc main defs.fun
+//    amm fun.sc main fact.fun
+//
+//  or
+// 
+//    amm fun.sc run defs.fun
+//    amm fun.sc run fact.fun   
+//
+// the first prints out the JVM instructions
+// the second runs the generated class files
+
 
 import $file.fun_tokens, fun_tokens._
 import $file.fun_parser, fun_parser._ 
@@ -26,7 +41,8 @@
 // calculating the maximal needed stack size
 def max_stack_exp(e: Exp): Int = e match {
   case Call(_, args) => args.map(max_stack_exp).sum
-  case If(a, e1, e2) => max_stack_bexp(a) + (List(max_stack_exp(e1), max_stack_exp(e2)).max)
+  case If(a, e1, e2) => 
+    max_stack_bexp(a) + (List(max_stack_exp(e1), max_stack_exp(e2)).max)
   case Write(e) => max_stack_exp(e) + 1
   case Var(_) => 1
   case Num(_) => 1
@@ -61,15 +77,19 @@
 
 type Env = Map[String, Int]
 
+def compile_op(op: String) = op match {
+  case "+" => i"iadd"
+  case "-" => i"isub"
+  case "*" => i"imul"
+  case "/" => i"idiv"
+  case "%" => i"irem"
+}
 
 def compile_expT(a: Exp, env : Env, name: String) : String = a match {
   case Num(i) => i"ldc $i"
   case Var(s) => i"iload ${env(s)}"
-  case Aop("+", a1, a2) => compile_expT(a1, env, "") ++ compile_expT(a2, env, "") ++ i"iadd"
-  case Aop("-", a1, a2) => compile_expT(a1, env, "") ++ compile_expT(a2, env, "") ++ i"isub"
-  case Aop("*", a1, a2) => compile_expT(a1, env, "") ++ compile_expT(a2, env, "") ++ i"imul"
-  case Aop("/", a1, a2) => compile_expT(a1, env, "") ++ compile_expT(a2, env, "") ++ i"idiv"
-  case Aop("%", a1, a2) => compile_expT(a1, env, "") ++ compile_expT(a2, env, "") ++ i"irem"
+  case Aop(op, a1, a2) => 
+    compile_expT(a1, env, "") ++ compile_expT(a2, env, "") ++ compile_op(op)
   case If(b, a1, a2) => {
     val if_else = Fresh("If_else")
     val if_end = Fresh("If_end")
@@ -141,6 +161,22 @@
   (library + instructions).replaceAllLiterally("XXX", class_name)
 }
 
+import ammonite.ops._
+
+def compile_to_file(prog: List[Decl], class_name: String) : Unit = 
+  write.over(pwd / s"$class_name.j", compile(prog, class_name))  
+
+def compile_and_run(prog: List[Decl], class_name: String) : Unit = {
+  println(s"Start of compilation")
+  compile_to_file(prog, class_name)
+  println(s"generated $class_name.j file")
+  os.proc("java", "-jar", "jasmin.jar", s"$class_name.j").call()
+  println(s"generated $class_name.class file")
+  println(s"Run program")
+  os.proc("java", s"${class_name}/${class_name}").call(stdout = os.Inherit)
+  println(s"done.")
+}
+
 
 @main
 def main(fname: String) = {
@@ -151,18 +187,11 @@
     println(compile(ast, class_name))
 }
 
-/*
-
-import scala.sys.process._
-
-def compile_run(class_name: String) : Unit = {
-  compile_file(class_name)
-  (s"java -jar jvm/jasmin-2.4/jasmin.jar ${class_name}.j").!!
-  println("Time: " + time_needed(2, (s"java ${class_name}/${class_name}").!))
+@main
+def run(fname: String) = {
+    val path = os.pwd / fname
+    val class_name = fname.stripSuffix("." ++ path.ext)
+    val tks = tokenise(os.read(path))
+    val ast = parse_tks(tks)
+    compile_and_run(ast, class_name)
 }
-
-
-//examples
-compile_run("defs")
-compile_run("fact")
-*/
Binary file progs/fun/jasmin.jar has changed
Binary file slides/slides08.pdf has changed
--- a/slides/slides08.tex	Fri Nov 27 13:53:06 2020 +0000
+++ b/slides/slides08.tex	Tue Dec 01 05:41:12 2020 +0000
@@ -62,216 +62,216 @@
 \end{frame}
 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 
-%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
-\begin{frame}[c]
+% %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+% \begin{frame}[c]
 
-\begin{center}
-\bl{\begin{tabular}{@{}lcl@{}}
-\meta{Stmt} & $::=$ &  $\texttt{skip}$\\
-              & $|$ & \textit{Id}\;\texttt{:=}\;\meta{AExp}\\
-              & $|$ & \texttt{if}\; \meta{BExp} \;\texttt{then}\; \meta{Block} \;\texttt{else}\; \meta{Block}\\
-              & $|$ & \texttt{while}\; \meta{BExp} \;\texttt{do}\; \meta{Block}\\
-              & $|$ & \texttt{read}\;\textit{Id}\\
-              & $|$ & \texttt{write}\;\textit{Id}\\
-              & $|$ & \texttt{write}\;\textit{String}\medskip\\
-\meta{Stmts} & $::=$ &  \meta{Stmt} \;\texttt{;}\; \meta{Stmts}\\
-              & $|$ & \meta{Stmt}\medskip\\
-\meta{Block} & $::=$ &  \texttt{\{}\,\meta{Stmts}\,\texttt{\}}\\
-                & $|$ & \meta{Stmt}\medskip\\
-\meta{AExp} & $::=$ & \ldots\\
-\meta{BExp} & $::=$ & \ldots\\
-\end{tabular}}
-\end{center}
-\end{frame}
-%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%   
+% \begin{center}
+% \bl{\begin{tabular}{@{}lcl@{}}
+% \meta{Stmt} & $::=$ &  $\texttt{skip}$\\
+%               & $|$ & \textit{Id}\;\texttt{:=}\;\meta{AExp}\\
+%               & $|$ & \texttt{if}\; \meta{BExp} \;\texttt{then}\; \meta{Block} \;\texttt{else}\; \meta{Block}\\
+%               & $|$ & \texttt{while}\; \meta{BExp} \;\texttt{do}\; \meta{Block}\\
+%               & $|$ & \texttt{read}\;\textit{Id}\\
+%               & $|$ & \texttt{write}\;\textit{Id}\\
+%               & $|$ & \texttt{write}\;\textit{String}\medskip\\
+% \meta{Stmts} & $::=$ &  \meta{Stmt} \;\texttt{;}\; \meta{Stmts}\\
+%               & $|$ & \meta{Stmt}\medskip\\
+% \meta{Block} & $::=$ &  \texttt{\{}\,\meta{Stmts}\,\texttt{\}}\\
+%                 & $|$ & \meta{Stmt}\medskip\\
+% \meta{AExp} & $::=$ & \ldots\\
+% \meta{BExp} & $::=$ & \ldots\\
+% \end{tabular}}
+% \end{center}
+% \end{frame}
+% %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%   
 
-%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
-\begin{frame}[t,fragile]
-\frametitle{Compiling AExps}
+% %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+% \begin{frame}[t,fragile]
+% \frametitle{Compiling AExps}
 
-For example \bl{$1 + ((2 * 3) + (4 - 3))$}:\medskip
+% For example \bl{$1 + ((2 * 3) + (4 - 3))$}:\medskip
 
-\begin{columns}[T]
-\begin{column}{.3\textwidth}
-\begin{center}
-\bl{\begin{tikzpicture}
-\tikzset{level distance=12mm,sibling distance=4mm}
-\tikzset{edge from parent/.style={draw,very thick}}
-\Tree [.$+$ [.$1$ ] [.$+$ [.$*$ $2$ $3$ ] [.$-$ $4$ $3$ ]]]
-\end{tikzpicture}}
-\end{center}
-\end{column}
-\begin{column}{.3\textwidth}
-\begin{lstlisting}[language=JVMIS,numbers=none]
-ldc 1 
-ldc 2 
-ldc 3 
-imul 
-ldc 4 
-ldc 3 
-isub 
-iadd 
-iadd
-\end{lstlisting}
-\end{column}
-\end{columns}\bigskip
+% \begin{columns}[T]
+% \begin{column}{.3\textwidth}
+% \begin{center}
+% \bl{\begin{tikzpicture}
+% \tikzset{level distance=12mm,sibling distance=4mm}
+% \tikzset{edge from parent/.style={draw,very thick}}
+% \Tree [.$+$ [.$1$ ] [.$+$ [.$*$ $2$ $3$ ] [.$-$ $4$ $3$ ]]]
+% \end{tikzpicture}}
+% \end{center}
+% \end{column}
+% \begin{column}{.3\textwidth}
+% \begin{lstlisting}[language=JVMIS,numbers=none]
+% ldc 1 
+% ldc 2 
+% ldc 3 
+% imul 
+% ldc 4 
+% ldc 3 
+% isub 
+% iadd 
+% iadd
+% \end{lstlisting}
+% \end{column}
+% \end{columns}\bigskip
 
-\small
-Traverse tree in post-order \bl{$\Rightarrow$} code for 
-stack-machine
+% \small
+% Traverse tree in post-order \bl{$\Rightarrow$} code for 
+% stack-machine
 
-\end{frame}
-%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% 
+% \end{frame}
+% %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% 
 
-%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
-\begin{frame}[c,fragile]
-\frametitle{Compiling AExps}
+% %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+% \begin{frame}[c,fragile]
+% \frametitle{Compiling AExps}
 
-\bl{
-\begin{center}
-\begin{tabular}{lcl}
-$\textit{compile}(n, E)$ & $\dn$ & $\pcode{ldc}\;n$\smallskip\\
-$\textit{compile}(a_1 + a_2, E)$ & $\dn$ \\
-\multicolumn{3}{c}{$\qquad\textit{compile}(a_1, E) \;@\;\textit{compile}(a_2, E)\;@\; \pcode{iadd}$}\smallskip\\
-$\textit{compile}(a_1 - a_2, E)$ & $\dn$ \\
-\multicolumn{3}{c}{$\qquad\textit{compile}(a_1, E) \;@\; \textit{compile}(a_2, E)\;@\; \pcode{isub}$}\smallskip\\
-$\textit{compile}(a_1 * a_2, E)$ & $\dn$ \\
-\multicolumn{3}{c}{$\qquad\textit{compile}(a_1, E) \;@\; \textit{compile}(a_2, E)\;@\; \pcode{imul}$}\smallskip\\
-$\textit{compile}(a_1 \backslash a_2, E)$ & $\dn$\\ 
-\multicolumn{3}{c}{$\qquad\textit{compile}(a_1, E) \;@\; \textit{compile}(a_2, E)\;@\; \pcode{idiv}$}\smallskip\\
-$\textit{compile}(x, E)$ & $\dn$ & $\pcode{iload}\;E(x)$\\
-\end{tabular}
-\end{center}}
+% \bl{
+% \begin{center}
+% \begin{tabular}{lcl}
+% $\textit{compile}(n, E)$ & $\dn$ & $\pcode{ldc}\;n$\smallskip\\
+% $\textit{compile}(a_1 + a_2, E)$ & $\dn$ \\
+% \multicolumn{3}{c}{$\qquad\textit{compile}(a_1, E) \;@\;\textit{compile}(a_2, E)\;@\; \pcode{iadd}$}\smallskip\\
+% $\textit{compile}(a_1 - a_2, E)$ & $\dn$ \\
+% \multicolumn{3}{c}{$\qquad\textit{compile}(a_1, E) \;@\; \textit{compile}(a_2, E)\;@\; \pcode{isub}$}\smallskip\\
+% $\textit{compile}(a_1 * a_2, E)$ & $\dn$ \\
+% \multicolumn{3}{c}{$\qquad\textit{compile}(a_1, E) \;@\; \textit{compile}(a_2, E)\;@\; \pcode{imul}$}\smallskip\\
+% $\textit{compile}(a_1 \backslash a_2, E)$ & $\dn$\\ 
+% \multicolumn{3}{c}{$\qquad\textit{compile}(a_1, E) \;@\; \textit{compile}(a_2, E)\;@\; \pcode{idiv}$}\smallskip\\
+% $\textit{compile}(x, E)$ & $\dn$ & $\pcode{iload}\;E(x)$\\
+% \end{tabular}
+% \end{center}}
 
-\end{frame}
-%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% 
+% \end{frame}
+% %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% 
 
-%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
-\begin{frame}[c,fragile]
-\frametitle{Compiling Ifs}
+% %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+% \begin{frame}[c,fragile]
+% \frametitle{Compiling Ifs}
 
-For example
+% For example
 
-\begin{lstlisting}[mathescape,numbers=none,language=While]
-if 1 = 1 then x := 2 else y := 3
-\end{lstlisting}
+% \begin{lstlisting}[mathescape,numbers=none,language=While]
+% if 1 = 1 then x := 2 else y := 3
+% \end{lstlisting}
 
 
-\begin{center}
-\begin{lstlisting}[mathescape,language=JVMIS,numbers=none]
-   ldc 1
-   ldc 1
-   if_icmpne L_ifelse $\quad\tikz[remember picture] \node (C) {\mbox{}};$
-   ldc 2
-   istore 0
-   goto L_ifend $\quad\tikz[remember picture] \node (A) {\mbox{}};$
-L_ifelse: $\quad\tikz[remember picture] \node[] (D) {\mbox{}};$
-   ldc 3
-   istore 1
-L_ifend: $\quad\tikz[remember picture] \node[] (B) {\mbox{}};$
-\end{lstlisting}
-\end{center}
+% \begin{center}
+% \begin{lstlisting}[mathescape,language=JVMIS,numbers=none]
+%    ldc 1
+%    ldc 1
+%    if_icmpne L_ifelse $\quad\tikz[remember picture] \node (C) {\mbox{}};$
+%    ldc 2
+%    istore 0
+%    goto L_ifend $\quad\tikz[remember picture] \node (A) {\mbox{}};$
+% L_ifelse: $\quad\tikz[remember picture] \node[] (D) {\mbox{}};$
+%    ldc 3
+%    istore 1
+% L_ifend: $\quad\tikz[remember picture] \node[] (B) {\mbox{}};$
+% \end{lstlisting}
+% \end{center}
 
-\begin{tikzpicture}[remember picture,overlay]
-  \draw[->,very thick] (A) edge [->,to path={-- ++(10mm,0mm) 
-           -- ++(0mm,-17.3mm) |- (\tikztotarget)},line width=1mm] (B.east);
-  \draw[->,very thick] (C) edge [->,to path={-- ++(10mm,0mm) 
-           -- ++(0mm,-17.3mm) |- (\tikztotarget)},line width=1mm] (D.east);
-\end{tikzpicture}
+% \begin{tikzpicture}[remember picture,overlay]
+%   \draw[->,very thick] (A) edge [->,to path={-- ++(10mm,0mm) 
+%            -- ++(0mm,-17.3mm) |- (\tikztotarget)},line width=1mm] (B.east);
+%   \draw[->,very thick] (C) edge [->,to path={-- ++(10mm,0mm) 
+%            -- ++(0mm,-17.3mm) |- (\tikztotarget)},line width=1mm] (D.east);
+% \end{tikzpicture}
 
-\end{frame}
-%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% 
+% \end{frame}
+% %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% 
 
-%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
-\begin{frame}[c,fragile]
-\frametitle{Compiling Whiles}
+% %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+% \begin{frame}[c,fragile]
+% \frametitle{Compiling Whiles}
 
-For example
+% For example
 
-\begin{lstlisting}[mathescape,numbers=none,language=While]
-while x <= 10 do x := x + 1
-\end{lstlisting}
+% \begin{lstlisting}[mathescape,numbers=none,language=While]
+% while x <= 10 do x := x + 1
+% \end{lstlisting}
 
 
-\begin{center}
-\begin{lstlisting}[mathescape,language=JVMIS,numbers=none]
-L_wbegin: $\quad\tikz[remember picture] \node[] (LB) {\mbox{}};$
-   iload 0
-   ldc 10
-   if_icmpgt L_wend $\quad\tikz[remember picture] \node (LC) {\mbox{}};$
-   iload 0
-   ldc 1
-   iadd
-   istore 0
-   goto L_wbegin $\quad\tikz[remember picture] \node (LA) {\mbox{}};$
-L_wend: $\quad\tikz[remember picture] \node[] (LD) {\mbox{}};$
-\end{lstlisting}
-\end{center}
+% \begin{center}
+% \begin{lstlisting}[mathescape,language=JVMIS,numbers=none]
+% L_wbegin: $\quad\tikz[remember picture] \node[] (LB) {\mbox{}};$
+%    iload 0
+%    ldc 10
+%    if_icmpgt L_wend $\quad\tikz[remember picture] \node (LC) {\mbox{}};$
+%    iload 0
+%    ldc 1
+%    iadd
+%    istore 0
+%    goto L_wbegin $\quad\tikz[remember picture] \node (LA) {\mbox{}};$
+% L_wend: $\quad\tikz[remember picture] \node[] (LD) {\mbox{}};$
+% \end{lstlisting}
+% \end{center}
 
-\begin{tikzpicture}[remember picture,overlay]
-  \draw[->,very thick] (LA) edge [->,to path={-- ++(12mm,0mm) 
-           -- ++(0mm,17.3mm) |- (\tikztotarget)},line width=1mm] (LB.east);
-  \draw[->,very thick] (LC) edge [->,to path={-- ++(12mm,0mm) 
-           -- ++(0mm,-17.3mm) |- (\tikztotarget)},line width=1mm] (LD.east);
-\end{tikzpicture}
+% \begin{tikzpicture}[remember picture,overlay]
+%   \draw[->,very thick] (LA) edge [->,to path={-- ++(12mm,0mm) 
+%            -- ++(0mm,17.3mm) |- (\tikztotarget)},line width=1mm] (LB.east);
+%   \draw[->,very thick] (LC) edge [->,to path={-- ++(12mm,0mm) 
+%            -- ++(0mm,-17.3mm) |- (\tikztotarget)},line width=1mm] (LD.east);
+% \end{tikzpicture}
 
-\end{frame}
-%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% 
+% \end{frame}
+% %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% 
 
-%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
-\begin{frame}[c,fragile]
-\frametitle{Compiling Writes}
+% %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+% \begin{frame}[c,fragile]
+% \frametitle{Compiling Writes}
 
-\small
-\begin{lstlisting}[language=JVMIS,mathescape,
-                   numbers=none,xleftmargin=-6mm]
-.method public static write(I)V 
-  .limit locals 1 
-  .limit stack 2 
-  getstatic java/lang/System/out 
-                            Ljava/io/PrintStream; 
-  iload 0
-  invokevirtual java/io/PrintStream/println(I)V 
-  return 
-.end method
+% \small
+% \begin{lstlisting}[language=JVMIS,mathescape,
+%                    numbers=none,xleftmargin=-6mm]
+% .method public static write(I)V 
+%   .limit locals 1 
+%   .limit stack 2 
+%   getstatic java/lang/System/out 
+%                             Ljava/io/PrintStream; 
+%   iload 0
+%   invokevirtual java/io/PrintStream/println(I)V 
+%   return 
+% .end method
 
 
 
-iload $E(x)$ 
-invokestatic XXX/XXX/write(I)V
-\end{lstlisting}
+% iload $E(x)$ 
+% invokestatic XXX/XXX/write(I)V
+% \end{lstlisting}
 
-\end{frame}
-%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%   
+% \end{frame}
+% %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%   
 
-%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
-\begin{frame}[c,fragile]
-\frametitle{Compiling Main}
+% %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+% \begin{frame}[c,fragile]
+% \frametitle{Compiling Main}
 
-\footnotesize
-\begin{lstlisting}[language=JVMIS,mathescape,
-                   numbers=none,xleftmargin=-6mm]
-.class public XXX.XXX
-.super java/lang/Object
+% \footnotesize
+% \begin{lstlisting}[language=JVMIS,mathescape,
+%                    numbers=none,xleftmargin=-6mm]
+% .class public XXX.XXX
+% .super java/lang/Object
 
-.method public <init>()V
-    aload_0
-    invokenonvirtual java/lang/Object/<init>()V
-    return
-.end method
+% .method public <init>()V
+%     aload_0
+%     invokenonvirtual java/lang/Object/<init>()V
+%     return
+% .end method
 
-.method public static main([Ljava/lang/String;)V
-    .limit locals 200
-    .limit stack 200
+% .method public static main([Ljava/lang/String;)V
+%     .limit locals 200
+%     .limit stack 200
 
-      $\textit{\ldots{}here comes the compiled code\ldots}$
+%       $\textit{\ldots{}here comes the compiled code\ldots}$
 
-    return
-.end method
-\end{lstlisting}
+%     return
+% .end method
+% \end{lstlisting}
 
-\end{frame}
-%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%   
+% \end{frame}
+% %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%   
 
 
 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%