--- a/handouts/ho02.tex Wed Oct 02 14:05:36 2019 +0100
+++ b/handouts/ho02.tex Thu Oct 03 11:12:00 2019 +0100
@@ -1,3 +1,4 @@
+% !TEX program = xelatex
\documentclass{article}
\usepackage{../style}
\usepackage{../langs}
@@ -148,7 +149,7 @@
whether a string is member of this set or not. In contrast our
matching algorithm will operate on the regular expression $r$ and
string $s$, only, which are both finite objects. Before we explain
-the matching algorithm, however, let us have a closer look at what it
+the matching algorithm, let us have a closer look at what it
means when two regular expressions are equivalent.
\subsection*{Regular Expression Equivalences}
--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/progs/fun_llvm.scala Thu Oct 03 11:12:00 2019 +0100
@@ -0,0 +1,203 @@
+// A Small Compiler for a Simple Functional Language
+// (includes an external lexer and parser)
+//
+// call with
+//
+// scala fun.scala fact
+//
+// scala fun.scala defs
+//
+// this will generate a .j file and run the jasmin
+// assembler (installed at jvm/jasmin-2.4/jasmin.jar)
+// it runs the resulting JVM file twice for timing
+// purposes.
+
+
+
+
+object Compiler {
+
+import java.io._
+import scala.util._
+import scala.sys.process._
+
+// Abstract syntax trees for the Fun language
+abstract class Exp extends Serializable
+abstract class BExp extends Serializable
+abstract class Decl extends Serializable
+
+case class Def(name: String, args: List[String], body: Exp) extends Decl
+case class Main(e: Exp) extends Decl
+
+case class Call(name: String, args: List[Exp]) extends Exp
+case class If(a: BExp, e1: Exp, e2: Exp) extends Exp
+case class Write(e: Exp) extends Exp
+case class Var(s: String) extends Exp
+case class Num(i: Int) extends Exp
+case class Aop(o: String, a1: Exp, a2: Exp) extends Exp
+case class Sequence(e1: Exp, e2: Exp) extends Exp
+case class Bop(o: String, a1: Exp, a2: Exp) extends BExp
+
+
+// compiler - built-in functions
+// copied from http://www.ceng.metu.edu.tr/courses/ceng444/link/jvm-cpm.html
+//
+
+val library = """
+.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 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
+
+"""
+
+// for generating new labels
+var counter = -1
+
+def Fresh(x: String) = {
+ counter += 1
+ x ++ "_" ++ counter.toString()
+}
+
+// convenient string interpolations
+// for instructions, labels and methods
+import scala.language.implicitConversions
+import scala.language.reflectiveCalls
+
+implicit def sring_inters(sc: StringContext) = new {
+ def i(args: Any*): String = " " ++ sc.s(args:_*) ++ "\n"
+ def l(args: Any*): String = sc.s(args:_*) ++ ":\n"
+ def m(args: Any*): String = sc.s(args:_*) ++ "\n"
+}
+
+
+type Env = Map[String, Int]
+
+// compile expressions
+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 If(b, a1, a2) => {
+ val if_else = Fresh("If_else")
+ val if_end = Fresh("If_end")
+ compile_bexp(b, env, if_else) ++
+ compile_exp(a1, env) ++
+ i"goto $if_end" ++
+ l"$if_else" ++
+ compile_exp(a2, env) ++
+ l"$if_end"
+ }
+ case Call(name, args) => {
+ val is = "I" * args.length
+ args.map(a => compile_exp(a, env)).mkString ++
+ i"invokestatic XXX/XXX/$name($is)I"
+ }
+ case Sequence(a1, a2) => {
+ compile_exp(a1, env) ++ i"pop" ++ compile_exp(a2, env)
+ }
+ case Write(a1) => {
+ compile_exp(a1, env) ++
+ i"dup" ++
+ i"invokestatic XXX/XXX/write(I)V"
+ }
+}
+
+// compile boolean expressions
+def compile_bexp(b: BExp, env : Env, jmp: String) : String = b match {
+ case Bop("==", a1, a2) =>
+ compile_exp(a1, env) ++ compile_exp(a2, env) ++ i"if_icmpne $jmp"
+ case Bop("!=", a1, a2) =>
+ compile_exp(a1, env) ++ compile_exp(a2, env) ++ i"if_icmpeq $jmp"
+ case Bop("<", a1, a2) =>
+ compile_exp(a1, env) ++ compile_exp(a2, env) ++ i"if_icmpge $jmp"
+ case Bop("<=", a1, a2) =>
+ compile_exp(a1, env) ++ compile_exp(a2, env) ++ i"if_icmpgt $jmp"
+}
+
+// compile function for declarations and main
+def compile_decl(d: Decl) : String = d match {
+ case Def(name, args, a) => {
+ val env = args.zipWithIndex.toMap
+ val is = "I" * args.length
+ m".method public static $name($is)I" ++
+ m".limit locals ${args.length.toString}" ++
+ m".limit stack ${1 + max_stack_exp(a)}" ++
+ l"${name}_Start" ++
+ compile_exp(a, env) ++
+ i"ireturn" ++
+ m".end method\n"
+ }
+ case Main(a) => {
+ m".method public static main([Ljava/lang/String;)V" ++
+ m".limit locals 200" ++
+ m".limit stack 200" ++
+ compile_exp(a, Map()) ++
+ i"invokestatic XXX/XXX/write(I)V" ++
+ i"return" ++
+ m".end method\n"
+ }
+}
+
+// main compiler functions
+
+def time_needed[T](i: Int, code: => T) = {
+ val start = System.nanoTime()
+ for (j <- 1 to i) code
+ val end = System.nanoTime()
+ (end - start)/(i * 1.0e9)
+}
+
+def deserialise[T](fname: String) : Try[T] = {
+ import scala.util.Using
+ Using(new ObjectInputStream(new FileInputStream(fname))) {
+ in => in.readObject.asInstanceOf[T]
+ }
+}
+
+def compile(class_name: String) : String = {
+ val ast = deserialise[List[Decl]](class_name ++ ".prs").getOrElse(Nil)
+ val instructions = ast.map(compile_decl).mkString
+ (library + instructions).replaceAllLiterally("XXX", class_name)
+}
+
+def compile_to_file(class_name: String) = {
+ val output = compile(class_name)
+ scala.tools.nsc.io.File(s"${class_name}.j").writeAll(output)
+}
+
+def compile_and_run(class_name: String) : Unit = {
+ compile_to_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}").!))
+}
+
+
+// some examples of .fun files
+//compile_to_file("fact")
+//compile_and_run("fact")
+//compile_and_run("defs")
+
+
+def main(args: Array[String]) =
+ compile_and_run(args(0))
+
+
+}
\ No newline at end of file