afl-material: comparison progs/compile

equal deleted inserted replaced

-:b560f78781b9
+:2fcd7c2da729
 // A Small Compiler for the WHILE Language
+//
 //  - includes arrays and a small parser for
-//    translated BF programs
+//    WHILE programs
+//
+//  - transpiles BF programs into WHILE programs
+//    and compiles and runs them
+//
+// Call with
+//
+// scala compiler_arr.scala
 // the abstract syntax trees
 abstract class Stmt
 abstract class AExp
 abstract class BExp
 type Block = List[Stmt]
 // statements
 case object Skip extends Stmt
-case class Array(s: String, n: Int) extends Stmt
+case class ArrayDef(s: String, n: Int) extends Stmt
 case class If(a: BExp, bl1: Block, bl2: Block) extends Stmt
 case class While(b: BExp, bl: Block) extends Stmt
-case class Assign(s: String, a: AExp) extends Stmt
+case class Assign(s: String, a: AExp) extends Stmt             // var := exp
-case class AssignA(s: String, a1: AExp, a2: AExp) extends Stmt
+case class AssignA(s: String, a1: AExp, a2: AExp) extends Stmt // arr[exp1] := exp2
 case class Write(s: String) extends Stmt
 case class Read(s: String) extends Stmt
 // arithmetic expressions
 case class Var(s: String) extends AExp
 i2c       ; Int => Char
 invokevirtual java/io/PrintStream/print(C)V   ; println(I)V => print(C)V
 return
 .end method
-.method public static read()I
-.limit locals 10
-.limit stack 10
-ldc 0
-istore 1  ; this will hold our final integer
-Label1:
-getstatic java/lang/System/in Ljava/io/InputStream;
-invokevirtual java/io/InputStream/read()I
-istore 2
-iload 2
-ldc 10   ; the newline delimiter
-isub
-ifeq Label2
-iload 2
-ldc 32   ; the space delimiter
-isub
-ifeq Label2
-iload 2
-ldc 48   ; we have our digit in ASCII, have to subtract it from 48
-isub
-ldc 10
-iload 1
-imul
-iadd
-istore 1
-goto Label1
-Label2:
-;when we come here we have our integer computed in local variable 1
-iload 1
-ireturn
-.end method
 .method public static main([Ljava/lang/String;)V
 .limit locals 200
 .limit stack 200
 """
 }
 // arithmetic expression compilation
 def compile_aexp(a: AExp, env : Env) : String = a match {
 case Num(i) => i"ldc $i"
-case Var(s) => i"iload ${env(s)} \t\t; $s"
+case Var(s) => i"iload ${env(s)}"
 case Aop(op, a1, a2) =>
 compile_aexp(a1, env) ++ compile_aexp(a2, env) ++ compile_op(op)
 case Ref(s, a) =>
 i"aload ${env(s)}" ++ compile_aexp(a, env) ++  i"iaload"
 }
 // boolean expression compilation
 def compile_bexp(b: BExp, env : Env, jmp: String) : String = b match {
 case True => ""
 case False => i"goto $jmp"
 case Bop("==", a1, a2) =>
 compile_aexp(a1, env) ++ compile_aexp(a2, env) ++ i"if_icmpne $jmp"
 case Bop("!=", a1, a2) =>
 compile_aexp(a1, env) ++ compile_aexp(a2, env) ++ i"if_icmpeq $jmp"
 case Read(x) => {
 val index = env.getOrElse(x, env.keys.size)
 (i"invokestatic XXX/XXX/read()I" ++
 i"istore $index \t\t; $x", env + (x -> index))
 }
-case Array(s: String, n: Int) => {
+case ArrayDef(s: String, n: Int) => {
 val index = if (env.isDefinedAt(s)) throw new Exception("array def error") else
 env.keys.size
 (i"ldc $n" ++
 i"newarray int" ++
 i"astore $index", env + (s -> index))
 compile_aexp(a2, env) ++
 i"iastore", env)
 }
 }
-// compilation of a block (i.e. list of instructions)
+// compilation of a block (i.e. list of statements)
 def compile_block(bl: Block, env: Env) : (String, Env) = bl match {
 case Nil => ("", env)
 case s::bl => {
 val (instrs1, env1) = compile_stmt(s, env)
 val (instrs2, env2) = compile_block(bl, env1)
 }
 // main compilation function for blocks
 def compile(bl: Block, class_name: String) : String = {
-val instructions = compile_block(bl, Map.empty)._1
+val instructions = compile_block(bl, Map())._1
-(beginning ++ instructions.mkString ++ ending).replaceAllLiterally("XXX", class_name)
+(beginning ++ instructions ++ ending).replaceAllLiterally("XXX", class_name)
 }
 // Fibonacci numbers as a test-case
 val fib_test =
 //  minus2 := minus1 + minus2;
 Assign("minus1",Var("temp")), //  minus1 := temp;
 Assign("n",Aop("-",Var("n"),Num(1))))), //  n := n - 1 };
 Write("minus1"))                 //  write minus1
-// prints out the JVM-assembly program
+// prints out the JVM-assembly instructions for fib
+//
 // println(compile(fib_test, "fib"))
+//
-// can be assembled with
+// can be assembled by hand with
 //
 //    java -jar jvm/jasmin-2.4/jasmin.jar fib.j
 //
 // and started with
 //
 //    java fib/fib
 import scala.util._
 import scala.sys.process._
-import scala.io
-def compile_tofile(bl: Block, class_name: String) = {
-val output = compile(bl, class_name)
-val fw = new java.io.FileWriter(class_name + ".j")
-fw.write(output)
-fw.close()
-}
-def compile_all(bl: Block, class_name: String) : Unit = {
-compile_tofile(bl, class_name)
-println("compiled ")
-val test = ("java -jar jvm/jasmin-2.4/jasmin.jar " + class_name + ".j").!!
-println("assembled ")
-}
 def time_needed[T](i: Int, code: => T) = {
 val start = System.nanoTime()
-for (j <- 1 to i) code
+for (j <- 2 to i) code
+val result = code
 val end = System.nanoTime()
-(end - start)/(i * 1.0e9)
+((end - start) / (i * 1.0e9), result)
 }
+def compile_to_file(bl: Block, class_name: String) : Unit =
-def compile_run(bl: Block, class_name: String) : Unit = {
+Using(new java.io.FileWriter(class_name + ".j")) {
-println("Start compilation")
+_.write(compile(bl, class_name))
-compile_all(bl, class_name)
+}
-println("Time: " + time_needed(1, ("java " + class_name + "/" + class_name).!))
-}
+def compile_and_run(bl: Block, class_name: String) : Unit = {
+println(s"Start compilation of $class_name")
+compile_to_file(bl, class_name)
+println("generated .j file")
+(s"java -jar jvm/jasmin-2.4/jasmin.jar ${class_name}.j").!!
+println("generated .class file ")
+println("Time: " + time_needed(1, (s"java ${class_name}/${class_name}").!)._1)
+}
 val arr_test =
-List(Array("a", 10),
+List(ArrayDef("a", 10),
-Array("b", 2),
+ArrayDef("b", 2),
 AssignA("a", Num(0), Num(10)),
 Assign("x", Ref("a", Num(0))),
 Write("x"),
 AssignA("b", Num(1), Num(5)),
 Assign("x", Ref("b", Num(1))),
 Write("x"))
-//compile_run(arr_test, "a")
+//compile_and_run(arr_test, "a")
 //====================
 // Parser Combinators
 //====================
 import scala.language.implicitConversions
 import scala.language.reflectiveCalls
+// more convenience for the semantic actions later on
+case class ~[+A, +B](_1: A, _2: B)
 type IsSeq[A] = A => Seq[_]
 abstract class Parser[I : IsSeq, T] {
 def parse(ts: I): Set[(T, I)]
 def parse_all(ts: I) : Set[T] =
 for ((head, tail) <- parse(ts); if (tail.isEmpty)) yield head
 }
-class SeqParser[I : IsSeq, T, S](p: => Parser[I, T], q: => Parser[I, S]) extends Parser[I, (T, S)] {
+class SeqParser[I : IsSeq, T, S](p: => Parser[I, T], q: => Parser[I, S]) extends Parser[I, ~[T, S]] {
 def parse(sb: I) =
 for ((head1, tail1) <- p.parse(sb);
-(head2, tail2) <- q.parse(tail1)) yield ((head1, head2), tail2)
+(head2, tail2) <- q.parse(tail1)) yield (new ~(head1, head2), tail2)
 }
 class AltParser[I : IsSeq, T](p: => Parser[I, T], q: => Parser[I, T]) extends Parser[I, T] {
 def parse(sb: I) = p.parse(sb) ++ q.parse(sb)
 }
 val NumParser = RegexParser("[0-9]+".r) ==> (s => s.toInt : Int)
 val IdParser = RegexParser("[a-z][a-z,0-9]*".r)
-// Grammar Rules
+// Grammar Rules for WHILE with arrays
 lazy val AExp: Parser[String, AExp] =
-(Te ~ "+" ~ AExp) ==> { case ((x, _), z) => Aop("+", x, z):AExp } |
+(Te ~ "+" ~ AExp) ==> { case x ~ _ ~ z => Aop("+", x, z):AExp } |
-(Te ~ "-" ~ AExp) ==> { case ((x, _), z) => Aop("-", x, z):AExp } | Te
+(Te ~ "-" ~ AExp) ==> { case x ~ _ ~ z => Aop("-", x, z):AExp } | Te
 lazy val Te: Parser[String, AExp] =
-(Fa ~ "*" ~ Te) ==> { case ((x, _), z) => Aop("*", x, z):AExp } | Fa
+(Fa ~ "*" ~ Te) ==> { case x ~ _ ~ z => Aop("*", x, z):AExp } | Fa
 lazy val Fa: Parser[String, AExp] =
-("(" ~ AExp ~ ")") ==> { case ((_, y), _) => y } |
+("(" ~ AExp ~ ")") ==> { case _ ~ y ~ _ => y } |
-(IdParser ~ "[" ~ AExp ~ "]") ==> { case (((x, _), y), _) => Ref(x, y) } |
+(IdParser ~ "[" ~ AExp ~ "]") ==> { case x ~ _ ~ y ~ _ => Ref(x, y) } |
 IdParser ==> Var |
 NumParser ==> Num
 // boolean expressions
 lazy val BExp: Parser[String, BExp] =
-(AExp ~ "=" ~ AExp) ==> { case ((x, y), z) => Bop("=", x, z):BExp } |
+(AExp ~ "=" ~ AExp) ==> { case x ~ y ~ z => Bop("=", x, z):BExp } |
-(AExp ~ "!=" ~ AExp) ==> { case ((x, y), z) => Bop("!=", x, z):BExp } |
+(AExp ~ "!=" ~ AExp) ==> { case x ~ y ~ z => Bop("!=", x, z):BExp } |
-(AExp ~ "<" ~ AExp) ==> { case ((x, y), z) => Bop("<", x, z):BExp } |
+(AExp ~ "<" ~ AExp) ==> { case x ~ y ~ z => Bop("<", x, z):BExp } |
-(AExp ~ ">" ~ AExp) ==> { case ((x, y), z) => Bop("<", z, x):BExp } |
+(AExp ~ ">" ~ AExp) ==> { case x ~ y ~ z => Bop("<", z, x):BExp } |
 ("true" ==> ((_) => True:BExp )) |
 ("false" ==> ((_) => False:BExp )) |
-("(" ~ BExp ~ ")") ==> { case ((x, y), z) => y}
+("(" ~ BExp ~ ")") ==> { case x ~ y ~ z => y}
 lazy val Stmt: Parser[String, Stmt] =
 ("skip" ==> (_ => Skip: Stmt)) |
-(IdParser ~ ":=" ~ AExp) ==> { case ((x, y), z) => Assign(x, z): Stmt } |
+(IdParser ~ ":=" ~ AExp) ==> { case x ~ y ~z => Assign(x, z): Stmt } |
 (IdParser ~ "[" ~ AExp ~ "]" ~ ":=" ~ AExp) ==> {
-case (((((x, y), z), v), w), u) => AssignA(x, z, u): Stmt } |
+case x ~ _ ~ z ~ _ ~ _ ~ u => AssignA(x, z, u): Stmt } |
 ("if" ~ BExp ~ "then" ~ Block ~ "else" ~ Block) ==>
-{ case (((((x,y),z),u),v),w) => If(y, u, w): Stmt } |
+{ case _ ~ y ~ _ ~ u ~ _ ~w => If(y, u, w): Stmt } |
-("while" ~ BExp ~ "do" ~ Block) ==> { case (((x, y), z), w) => While(y, w) } |
+("while" ~ BExp ~ "do" ~ Block) ==> { case _ ~ y ~ _ ~ w => While(y, w) } |
-("new" ~ IdParser ~ "[" ~ NumParser ~ "]") ==> { case ((((x, y), z), u), v) => Array(y, u) } |
+("new" ~ IdParser ~ "[" ~ NumParser ~ "]") ==> {
-("write" ~ IdParser) ==> { case (_, y) => Write(y) }
+case _ ~ y ~ _ ~ u ~ _ => ArrayDef(y, u) } |
+("write" ~ IdParser) ==> { case _ ~ y => Write(y) }
 lazy val Stmts: Parser[String, Block] =
-(Stmt ~ ";" ~ Stmts) ==> { case ((x, y), z) => x :: z : Block } |
+(Stmt ~ ";" ~ Stmts) ==> { case x ~ _ ~ z => x :: z : Block } |
 (Stmt ==> ((s) => List(s) : Block))
 lazy val Block: Parser[String, Block] =
-("{" ~ Stmts ~ "}") ==> { case ((x, y), z) => y} |
+("{" ~ Stmts ~ "}") ==> { case _ ~ y ~ _ => y} |
 (Stmt ==> (s => List(s)))
 //Stmts.parse_all("x2:=5+a")
 //Stmts.parse_all("x2:=5+a[3+a]")
 //Stmts.parse_all("a[x2+3]:=5+a[3+a]")
 result := minus2;
 write result
 """.replaceAll("\\s+", "")
 val fib_prog = Stmts.parse_all(fib).toList
-//compile_run(fib_prog.head, "fib")
+//compile_and_run(fib_prog.head, "fib")
+//======================================
-// BF
+// BF transpiler into WHILE with arrays
+//======================================
-// simple instructions
+// simple BF instructions translation
 def instr(c: Char) : String = c match {
 case '>' => "ptr := ptr + 1;"
 case '<' => "ptr := ptr - 1;"
 case '+' => "field[ptr] := field[ptr] + 1;"
 case '-' => "field[ptr] := field[ptr] - 1;"
 def instrs(prog: String) : String =
 prog.toList.map(instr).mkString
-// the mandelbrot.bf program is so large that
+// Note: the mandelbrot.bf program is so large that
-// it does not fit into the limitations of what the
+// it does not fit inside the limitations of what the
-// JVM imposes on methods.
+// JVM imposes on methods (only 64K of instructions).
-//
+// Therefore some optimisations are first applied to
-// below it just about fits by optimising [-] loops
+// BF programs before WHILE programs are created. The
-// and combining instructions
+// optimisations are
+//
+//  - replacing BF-loops of the form [-]
+//  - combining single increment/decrement instructions
+//
+// The size of the resulting .j-file is 270K.
 def splice(cs: List[Char], acc: List[(Char, Int)]) : List[(Char, Int)] = (cs, acc) match {
 case (Nil, acc) => acc
 case (c :: cs, Nil) => splice(cs, List((c, 1)))
 case (c :: cs, (d, n) :: acc) =>
 instrs2(prog) ++
 "skip"
 }
 def bf_run(prog: String, name: String) = {
-println("BF processing start")
+println(s"BF pre-processing of $name")
 val bf_string = bf_str(prog).replaceAll("\\s", "")
+println(s"BF parsing (program length ${bf_string.length} characters)")
-println(s"BF parsing start (string length ${bf_string.length})")
+val (time, bf_prog) = time_needed(1, Stmts.parse_all(bf_string).toList.head)
-val bf_prog = Stmts.parse_all(bf_string).toList.head
+println(s"BF generated WHILE program (needed $time for parsing)")
-println(s"BF Compile start ${bf_string.toList.length} characters")
+compile_and_run(ArrayDef("field", 30000) :: bf_prog, name)
-compile_run(Array("field", 30000) :: bf_prog, name)
 }
 // a benchmark program (counts down from 'Z' to 'A')
 val bf0 = """>++[<+++++++++++++>-]<[[>+>+<<-]>[<+>-]++++++++
 [>++++++++<-]>.[-]<<>++++++++++[>++++++++++[>++
 ++++++++[>++++++++++[>++++++++++[>++++++++++[>+
 +++++++++[-]<-]<-]<-]<-]<-]<-]<-]++++++++++."""
 bf_run(bf0, "bench")
+// Sierpinski triangle
 val bf1 = """++++++++[>+>++++<<-]>++>>+<[-[>>+<<-]+>>]>+[-<<<[
 ->[+[-]+>++>>>-<<]<[<]>>++++++[<<+++++>>-]+<<++.[-]<<
 ]>.>+[>>]>+]"""
 bf_run(bf1, "sier")
+// Helo World!
 bf_run("""++++++++[>++++[>++>+++>+++>+<<<<-]>+>+>->>+[<]<-]>>.>---.+++++++
 ..+++.>>.<-.<.+++.------.--------.>>+.>++.""", "hello")
+// Fibonacci
 val bf2 = """+++++++++++
 >+>>>>++++++++++++++++++++++++++++++++++++++++++++
 >++++++++++++++++++++++++++++++++<<<<<<[>[>>>>>>+>
 +<<<<<<<-]>>>>>>>[<<<<<<<+>>>>>>>-]<[>++++++++++[-
 <-[>>+>+<<<-]>>>[<<<+>>>-]+<[>[-]<[-]]>[<<[>>>+<<<
 <<<<<<<<<<[>>>+>+<<<<-]>>>>[<<<<+>>>>-]<-[>>.>.<<<
 [-]]<<[>>+>+<<<-]>>>[<<<+>>>-]<<[<+>-]>[<+>-]<<<-]"""
 bf_run(bf2, "fibs")
+// Mandelbrot Set
+//----------------
-bf_run("""      A mandelbrot set fractal viewer in brainf*** written by Erik Bosman
+//
+// Note: Parsing of the generated WHILE program (around 60K in size)
+// takes approximately 10 minutes
+bf_run("""A mandelbrot set fractal viewer in brainf*** written by Erik Bosman
 +++++++++++++[->++>>>+++++>++>+<<<<<<]>>>>>++++++>--->>>>>>>>>>+++++++++++++++[[
 >>>>>>>>>]+[<<<<<<<<<]>>>>>>>>>-]+[>>>>>>>>[-]>]<<<<<<<<<[<<<<<<<<<]>>>>>>>>[-]+
 <<<<<<<+++++[-[->>>>>>>>>+<<<<<<<<<]>>>>>>>>>]>>>>>>>+>>>>>>>>>>>>>>>>>>>>>>>>>>
 >+<<<<<<<<<<<<<<<<<[<<<<<<<<<]>>>[-]+[>>>>>>[>>>>>>>[-]>>]<<<<<<<<<[<<<<<<<<<]>>
 >>>>>[-]+<<<<<<++++[-[->>>>>>>>>+<<<<<<<<<]>>>>>>>>>]>>>>>>+<<<<<<+++++++[-[->>>

changeset 707	2fcd7c2da729
parent 696	3a5a7908517f
child 708	4980f421b3b0