--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/solutions/cw4a/compiler.sc Fri Jun 02 15:58:57 2023 +0100
@@ -0,0 +1,288 @@
+// Compiler for JVM
+//
+// call with
+//
+// amm2 compiler.sc
+//
+
+import $file.lexer
+import lexer._
+
+import $file.parser
+import parser._
+
+
+val beginning = """
+.class public XXX.XXX
+.super java/lang/Object
+
+.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/print(I)V
+ return
+.end method
+
+.method public static writes(Ljava/lang/String;)V
+ .limit stack 2
+ .limit locals 1
+ getstatic java/lang/System/out Ljava/io/PrintStream;
+ aload 0
+ invokevirtual java/io/PrintStream/print(Ljava/lang/String;)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
+
+; COMPILED CODE STARTS
+
+"""
+
+val ending = """
+; COMPILED CODE ENDS
+ return
+
+.end method
+"""
+
+// Compiler
+
+var counter = -1
+
+def Fresh(x: String) = {
+ counter += 1
+ x ++ "_" ++ counter.toString()
+}
+
+implicit def string_interpolations(sc: StringContext) = new {
+ def i(args: Any*): String = " " ++ sc.s(args:_*) ++ "\n"
+ def l(args: Any*): String = sc.s(args:_*) ++ ":\n"
+}
+
+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_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 Aop(op, a1, a2) =>
+ compile_aexp(a1, env) ++ compile_aexp(a2, env) ++ compile_op(op)
+}
+
+def compile_bop(op: String) = op match {
+ case "==" => "if_icmpne"
+ case "!=" => "if_icmpeq"
+ case "<" => "if_icmpge"
+ case ">" => "if_icmple"
+}
+
+def compile_bexp(b: BExp, env : Env, jmp: String) : String = b match {
+ case True => ""
+ case False => i"goto $jmp"
+ case And(b1, b2) => compile_bexp(b1, env, jmp) ++ compile_bexp(b2, env, jmp)
+ case Or(b1, b2) => {
+ val b1_false = Fresh("Or_second");
+ val or_end = Fresh("Or_end");
+ compile_bexp(b1, env, b1_false) ++
+ i"goto $or_end" ++
+ l"$b1_false" ++
+ compile_bexp(b2, env, jmp) ++
+ l"$or_end"
+ }
+ case Bop(op, a1, a2) =>
+ compile_aexp(a1, env) ++ compile_aexp(a2, env) ++ i"${compile_bop(op)} $jmp"
+}
+
+def compile_stmt(s: Stmt, env: Env, jmp: String) : (String, Env) = s match {
+ case Skip => ("", env)
+ case Break => (i"goto $jmp", env)
+ case Assign(x, a) => {
+ val index = env.getOrElse(x, env.keys.size)
+ (compile_aexp(a, env) ++ i"istore $index \t\t; $x", env + (x -> index))
+ }
+ case If(b, bl1, bl2) => {
+ val if_else = Fresh("If_else")
+ val if_end = Fresh("If_end")
+ val (instrs1, env1) = compile_block(bl1, env, jmp)
+ val (instrs2, env2) = compile_block(bl2, env1, jmp)
+ (compile_bexp(b, env, if_else) ++
+ instrs1 ++
+ i"goto $if_end" ++
+ l"$if_else" ++
+ instrs2 ++
+ l"$if_end", env2)
+ }
+ case While(b, bl) => {
+ val loop_begin = Fresh("Loop_begin")
+ val loop_end = Fresh("Loop_end")
+ val (instrs1, env1) = compile_block(bl, env, loop_end)
+ (l"$loop_begin" ++
+ compile_bexp(b, env, loop_end) ++
+ instrs1 ++
+ i"goto $loop_begin" ++
+ l"$loop_end", env1)
+ }
+ case For(id, lower, upper, code) => {
+ val (assignment_code, env1) = compile_stmt(Assign(id, lower), env, jmp) // id := lower;
+ val while_equivalent = While(
+ Or(Bop("<", Var(id), upper), Bop("==", Var(id), upper)), // while id <= upper do {
+ code ++ // code
+ List(
+ Assign(id, Aop("+", Var(id), Num(1))) // id := id + 1
+ )) // };
+
+ val (while_code, env2) = compile_stmt(while_equivalent, env1, jmp)
+ (assignment_code ++ while_code, env2)
+ }
+ case WriteId(x) => (i"iload ${env(x)} \t\t; $x" ++
+ i"invokestatic XXX/XXX/write(I)V", env)
+ case WriteString(x) => (s" ldc ${x}\n" ++
+ i"invokestatic XXX/XXX/writes(Ljava/lang/String;)V", env)
+ 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))
+ }
+}
+
+def compile_block(bl: Block, env: Env, jmp: String) : (String, Env) = bl match {
+ case Nil => ("", env)
+ case s::bl => {
+ val (instrs1, env1) = compile_stmt(s, env, jmp)
+ val (instrs2, env2) = compile_block(bl, env1, jmp)
+ (instrs1 ++ instrs2, env2)
+ }
+}
+
+def compile(bl: Block, class_name: String) : String = {
+ val instructions = compile_block(bl, Map.empty, "")._1
+ (beginning ++ instructions ++ ending).replaceAllLiterally("XXX", class_name)
+}
+
+// Compiling and running
+
+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 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
+ val end = System.nanoTime()
+ (end - start)/(i * 1.0e9)
+}
+
+def compile_run(bl: Block, class_name: String) : Unit = {
+ println("Start compilation")
+ compile_all(bl, class_name)
+ println("running")
+ println("Time: " + time_needed(1, ("java " + class_name + "/" + class_name).!))
+}
+
+// ---- Q1
+
+// Fibonacci
+
+val fibonacciProgram = """write "Fib";
+read n;
+minus1 := 0;
+minus2 := 1;
+while n > 0 do {
+ temp := minus2;
+ minus2 := minus1 + minus2;
+ minus1 := temp;
+ n := n - 1
+};
+write "Result";
+write minus2"""
+
+compile_all(Stmts.parse_all(tokenise(fibonacciProgram)).head, "fib")
+
+val factorialProgram = """write "Factorial";
+read n;
+fact := 1;
+
+while n > 0 do {
+ fact := n * fact;
+ n := n - 1
+};
+
+write "Result";
+write fact
+"""
+
+compile_all(Stmts.parse_all(tokenise(factorialProgram)).head, "factorial")
+
+// ---- Q3
+
+/* compile_run(Stmts.parse_all(tokenise("""for i := 1 upto 10 do {
+ for i := 1 upto 10 do {
+ write i
+ }
+}""")).head, "nestedloop") */
+
+
+compile_run(Stmts.parse_all(tokenise(os.read(os.pwd / "collatz2.while"))).head, "collatz2")
+
+
+
+compile_run(Stmts.parse_all(tokenise(os.read(os.pwd / "collatz3.while"))).head, "collatz3")