1 // Some more interesting testcases for the 

     2 // WHILE compiler with arrays, it includes: 

     3 //

     4 //  - a small parser for WHILE programs

     5 //

     6 //  - transpiles BF programs into WHILE programs

     7 //    and then compiles and runs them

     8 //

     9 //  - the power-example is the Mandelbrot set:

    10 //       

    11 //       * 65k for the transpiled WHILE program 

    12 //       * parsing uses around 30 secs using fastparse

    13 //       * the jasmin assembly file is 236k

    14 //       * the resulting Java program takes about 20 secs 

    15 //

    16 // Call with (X being 0,1,..,4)

    17 //

    18 //  amm compile_bfc.sc all

    19 //  amm compile_bfc.sc bfcX

    20 

    21 

    22 // load the compiler

    23 import $file.compile_arrays

    24 import compile_arrays._ 

    25 

    26 def time_needed[T](i: Int, code: => T) = {

    27   val start = System.nanoTime()

    28   for (j <- 2 to i) code

    29   val result = code

    30   val end = System.nanoTime()

    31   ((end - start) / (i * 1.0e9), result)

    32 }

    33 

    34 // for BF we have to change the write library-function,

    35 // because in BF integers are written out as characters

    36 val beginning = """

    37 .class public XXX.XXX

    38 .super java/lang/Object

    39 

    40 .method public static write(I)V 

    41     .limit locals 1 

    42     .limit stack 2 

    43     getstatic java/lang/System/out Ljava/io/PrintStream; 

    44     iload 0

    45     i2c                                           ; Int => Char

    46     invokevirtual java/io/PrintStream/print(C)V   ; println(I)V => print(C)V    

    47     return 

    48 .end method

    49 

    50 .method public static main([Ljava/lang/String;)V

    51    .limit locals 200

    52    .limit stack 200

    53 

    54 ; COMPILED CODE STARTS   

    55 

    56 """

    57 

    58 

    59 // modified main compilation function for blocks

    60 def compile(bl: Block, class_name: String) : String = {

    61   val instructions = compile_block(bl, Map())._1

    62   (beginning ++ instructions ++ ending).replace("XXX", class_name)

    63 }

    64 

    65 // automating the above

    66 import ammonite.ops._

    67 

    68 def compile_to_file(bl: Block, class_name: String) : Unit = 

    69   write.over(pwd / s"$class_name.j", compile(bl, class_name))  

    70 

    71 def compile_and_run(bl: Block, class_name: String) : Unit = {

    72   println(s"Start of compilation")

    73   compile_to_file(bl, class_name)

    74   println(s"generated $class_name.j file")

    75   val (jasmin_time, _) = 

    76     time_needed(1, os.proc("java", "-jar", "jasmin.jar", s"$class_name.j").call())

    77   println(s"generated $class_name.class file (in $jasmin_time secs).")

    78   val (running_time, output) = 

    79     time_needed(1, os.proc("java", s"${class_name}/${class_name}").call().out.text())

    80   println(output)

    81   println(s"done (in $running_time secs).")

    82 }

    83 

    84 

    85 //=====================================

    86 // Grammar Rules for WHILE with arrays

    87 //=====================================

    88 

    89 import fastparse._

    90 import MultiLineWhitespace._

    91 

    92 def lowercase [_ : P] = P( CharIn("a-z") )

    93 def uppercase[_ : P]  = P( CharIn("A-Z") )

    94 def letter[_ : P]     = P( lowercase | uppercase )

    95 def digit [_ : P]     = P( CharIn("0-9") )

    96 

    97 def Number[_ : P]: P[Int] =  P( digit.rep(1) ).!.map(_.toInt)

    98 def Ident[_ : P]: P[String] = P( letter ~ (letter | digit | "_").rep ).!

    99 

   100 // arithmetic expressions

   101 def AExp[_ : P]: P[AExp] = 

   102   P(  P(Te ~ "+" ~ AExp).map{ case (l, r) => Aop("+", l, r)} 

   103     | P(Te ~ "-" ~ AExp).map{ case (l, r) => Aop("-", l, r)}

   104     | Te )

   105 def Te[_ : P]: P[AExp] = 

   106   P(  P(Fa ~ "*" ~ Te).map{ case (l, r) => Aop("*", l, r)} 

   107     | Fa )   

   108 def Fa[_ : P]: P[AExp] = 

   109   P( "(" ~ AExp ~ ")" 

   110      | P (Ident ~ "[" ~ AExp ~ "]").map{Ref.tupled}

   111      | P(Number).map{Num} 

   112      | P(Ident).map{Var} )

   113 

   114 // boolean expressions

   115 def BExp[_ : P]: P[BExp] = 

   116   P(  P(AExp ~ "=" ~ AExp).map{ case (x, z) => Bop("=", x, z)} 

   117     | P(AExp ~ "!=" ~ AExp).map{ case (x, z) => Bop("!=", x, z)}  

   118     | P(AExp ~ "<" ~ AExp).map{ case (x, z) => Bop("<", x, z)}  

   119     | P(AExp ~ ">" ~ AExp).map{ case (x, z) => Bop("<", z, x)}  

   120     | P("true").map{ _ => True} 

   121     | P("false").map{ _ => False} 

   122     | "(" ~ BExp ~ ")" )

   123 

   124 // statements and blocks

   125 def Stmt[_ : P]: P[Stmt] =

   126   P(  P("skip").map( _ => Skip) 

   127     | P(Ident ~ ":=" ~ AExp).map{Assign.tupled} 

   128     | P(Ident ~ "[" ~ AExp ~ "]" ~ ":=" ~ AExp).map{AssignA.tupled} 

   129     | P("if" ~ BExp ~ "then" ~ Block ~ "else" ~ Block).map{If.tupled} 

   130     | P("while" ~ BExp ~ "do" ~ Block).map{While.tupled} 

   131     | P("new(" ~ Ident ~ "[" ~ Number ~ "])").map{ArrayDef.tupled} 

   132     | P("write(" ~ Ident ~ ")").map{Write} ) 

   133 

   134 def Stmts[_ : P]: P[Block] =

   135   P(  P(Stmt ~ ";" ~ Stmts).map{ case (x, z) => x :: z } 

   136     | P(Stmt).map{s => List(s)} ) 

   137 

   138 def Block[_ : P]: P[Block] =

   139   P(  "{" ~ Stmts ~ "}" 

   140     | P(Stmt).map(s => List(s)) )

   141 

   142 // some test cases for the parser

   143 

   144 //println(fastparse.parse("(1 + (2 + 5)) + 4", AExp(_)).get)

   145 //println(fastparse.parse("1 + 2 + 3 + 45", AExp(_)))

   146 //println(fastparse.parse("1 + 2 * 3", AExp(_)))

   147 //println(fastparse.parse("x + 2 * 3", AExp(_)))

   148 //println(fastparse.parse("x2 := 5 + a", Stmts(_)))

   149 //println(fastparse.parse("x2 := 5 + a[3+a]", Stmts(_)))

   150 //println(fastparse.parse("a[x2+3] := 5 + a[3+a]", Stmts(_)))

   151 //println(fastparse.parse("{x := 5; y := 8}", Block(_)))

   152 //println(fastparse.parse("if (false) then {x := 5} else {x := 10}", Block(_)))

   153 

   154 val fib = 

   155  """n := 10;

   156     minus1 := 0;

   157     minus2 := 1;

   158     temp:=0;

   159     while (n > 0) do {

   160       temp := minus2; 

   161       minus2 := minus1 + minus2;

   162       minus1 := temp;

   163       n := n - 1};

   164     result := minus2;

   165     write(result)

   166    """

   167 

   168 //println(fastparse.parse(fib, Stmts(_)).get.value)

   169 

   170 

   171 

   172 //======================================

   173 // BF transpiler into WHILE with arrays

   174 //======================================

   175 

   176 // simple BF instructions translation

   177 def instr(c: Char) : String = c match {

   178   case '>' => "ptr := ptr + 1;"

   179   case '<' => "ptr := ptr - 1;"

   180   case '+' => "mem[ptr] := mem[ptr] + 1;"

   181   case '-' => "mem[ptr] := mem[ptr] - 1;"

   182   case '.' => "x := mem[ptr]; write x;"

   183   //case ',' => "XXX" // "ptr = getchar();\n"

   184   case '['  => "while (mem[ptr] != 0) do {"

   185   case ']'  => "skip};"

   186   case _ => ""

   187 }

   188 

   189 def instrs(prog: String) : String =

   190   prog.toList.map(instr).mkString

   191 

   192 

   193 // Note: Unfortunately, the transpiled mandelbrot.bf program 

   194 // is so large that it does not fit inside the limitations of 

   195 // what the JVM imposes on methods (only 64K of instructions).

   196 // Therefore some optimisations are first applied to 

   197 // BF programs before WHILE programs are created. The

   198 // optimisations are 

   199 //  

   200 //  - replacing BF-loops of the form [-] with a new 0-instruction 

   201 //  - combining single increment/decrement instructions

   202 //

   203 // The size of the resulting .j-file is 270K.

   204 

   205 

   206 def splice(cs: List[Char], acc: List[(Char, Int)]) : List[(Char, Int)] = (cs, acc) match {

   207   case (Nil, acc) => acc

   208   case (c :: cs, Nil) => splice(cs, List((c, 1)))

   209   case (c :: cs, (d, n) :: acc) => 

   210     if (c == d) splice(cs, (c, n + 1) :: acc)

   211     else splice(cs, (c, 1) :: (d, n) :: acc)

   212 }

   213 

   214 def spl(s: String) = splice(s.toList, Nil).reverse

   215 

   216 def instr2(c: Char, n: Int) : String = c match {

   217   case '>' => s"ptr := ptr + $n;"

   218   case '<' => s"ptr := ptr - $n;"

   219   case '0' => s"mem[ptr] := 0;"

   220   case '+' => s"mem[ptr] := mem[ptr] + $n;"

   221   case '-' => s"mem[ptr] := mem[ptr] - $n;"

   222   case '.' => s"x := mem[ptr]; write(x);" 

   223   case '['  => "while (mem[ptr] != 0) do {" * n 

   224   case ']'  => "skip};" * n

   225   case _ => ""

   226 }

   227 

   228 def instrs2(prog: String) : String =

   229   spl(prog.replaceAll("""\[-\]""", "0")).map{ case (c, n) => instr2(c, n) }.mkString

   230 

   231 // adding the "header" to the BF program

   232 def bf_str(prog: String) : String = {

   233   "new(mem[30000]);" ++

   234   "ptr := 15000;" ++

   235   instrs2(prog) ++

   236   "skip"

   237 }

   238 

   239 

   240 def bf_run(prog: String, name: String) = {

   241   println(s"BF pre-processing of $name")

   242   val bf_string = bf_str(prog)

   243   println(s"BF parsing (program length ${bf_string.length} characters)")

   244   val (time, bf_prog) = 

   245     time_needed(1, fastparse.parse(bf_string, Stmts(_)).get.value)

   246   println(s"BF generated WHILE program (needed $time secs for parsing)")

   247   compile_and_run(bf_prog, name)

   248 }

   249 

   250 // a benchmark program (counts down from 'Z' to 'A')

   251 @doc(" Benchmark 'Z' to 'A'.")

   252 @main

   253 def bfc0() = bf_run(read(pwd / "benchmark.bf"), "bench")

   254 

   255 

   256 @doc(" Sierpinski triangle.")

   257 @main

   258 def bfc1() = bf_run(read(pwd / "sierpinski.bf"), "sier")

   259 

   260 // Hello World

   261 val bf2 = """++++++++[>++++[>++>+++>+++>+<<<<-]>+>+>->>+[<]<-]

   262       >>.>---.+++++++..+++.>>.<-.<.+++.------.--------.>>+.>++."""

   263 

   264 @doc(" Hello world.")

   265 @main

   266 def bfc2() = bf_run(bf2, "hello")

   267 

   268 // Fibonacci 

   269 val bf3 = """+++++++++++

   270       >+>>>>++++++++++++++++++++++++++++++++++++++++++++

   271       >++++++++++++++++++++++++++++++++<<<<<<[>[>>>>>>+>

   272       +<<<<<<<-]>>>>>>>[<<<<<<<+>>>>>>>-]<[>++++++++++[-

   273       <-[>>+>+<<<-]>>>[<<<+>>>-]+<[>[-]<[-]]>[<<[>>>+<<<

   274       -]>>[-]]<<]>>>[>>+>+<<<-]>>>[<<<+>>>-]+<[>[-]<[-]]

   275       >[<<+>>[-]]<<<<<<<]>>>>>[+++++++++++++++++++++++++

   276       +++++++++++++++++++++++.[-]]++++++++++<[->-<]>++++

   277       ++++++++++++++++++++++++++++++++++++++++++++.[-]<<

   278       <<<<<<<<<<[>>>+>+<<<<-]>>>>[<<<<+>>>>-]<-[>>.>.<<<

   279       [-]]<<[>>+>+<<<-]>>>[<<<+>>>-]<<[<+>-]>[<+>-]<<<-]

   280       [-]++++++++++."""

   281 

   282 @doc(" Fibonacci numbers.")

   283 @main

   284 def bfc3() = bf_run(bf3, "fibs")

   285 

   286 // Mandelbrot Set

   287 //----------------

   288 //

   289 // Note: Parsing of the generated WHILE program (around 60K in size)

   290 // takes approximately 10 minutes to parse with our parser combinators,

   291 // and approximately 30 seconds with Ammonite's fastparse.

   292 

   293 @doc(" Mandelbrot set.")

   294 @main

   295 def bfc4() = bf_run(read(pwd / "mandelbrot.bf"), "mandelbrot")

   296 

   297 

   298 // this unfortunately hits the capacity of the JVM, even with optimisations

   299 //@doc(" Coolatz serries up to 30.")

   300 //@main

   301 //def bfc5() = bf_run(read(pwd / "collatz.bf"), "coll")

   302 

   303 

   304 //

   305 @doc(" All benchmarks.")

   306 @main

   307 def all() = { bfc0(); bfc1(); bfc2(); bfc3(); bfc4() } 

   308 

   309 

   310