/* NSC -- new scala compiler
 * Copyright 2005-2011 LAMP/EPFL
 * @author  Martin Odersky
 */


package scala.tools.nsc
package backend
package icode;

import java.io.PrintWriter;

trait Primitives { self: ICodes =>

  /** This class represents a primitive operation. */
  class Primitive {
  }


  // type : (type) => type
  // range: type <- { BOOL, Ix, Ux, Rx }
  // jvm  : {i, l, f, d}neg
  case class Negation(kind: TypeKind) extends Primitive

  // type : zero ? (type) => BOOL : (type,type) => BOOL
  // range: type <- { BOOL, Ix, Ux, Rx, REF }
  // jvm  : if{eq, ne, lt, ge, le, gt}, if{null, nonnull}
  //        if_icmp{eq, ne, lt, ge, le, gt}, if_acmp{eq,ne}
  case class Test(op: TestOp, kind: TypeKind,  zero: Boolean)  extends Primitive

  // type : (type,type) => I4
  // range: type <- { Ix, Ux, Rx }
  // jvm  : lcmp, {f, d}cmp{l, g}
  case class Comparison(op: ComparisonOp, kind: TypeKind) extends Primitive

  // type : (type,type) => type
  // range: type <- { Ix, Ux, Rx }
  // jvm  : {i, l, f, d}{add, sub, mul, div, rem}
  case class Arithmetic(op: ArithmeticOp, kind: TypeKind) extends Primitive

  // type : (type,type) => type
  // range: type <- { BOOL, Ix, Ux }
  // jvm  : {i, l}{and, or, xor}
  case class Logical(op: LogicalOp, kind: TypeKind) extends Primitive

  // type : (type,I4) => type
  // range: type <- { Ix, Ux }
  // jvm  : {i, l}{shl, ushl, shr}
  case class Shift(op: ShiftOp, kind: TypeKind) extends Primitive

  // type : (src) => dst
  // range: src,dst <- { Ix, Ux, Rx }
  // jvm  : i2{l, f, d}, l2{i, f, d}, f2{i, l, d}, d2{i, l, f}, i2{b, c, s}
  case class Conversion(src: TypeKind, dst: TypeKind) extends Primitive;

  // type : (Array[REF]) => I4
  // range: type <- { BOOL, Ix, Ux, Rx, REF }
  // jvm  : arraylength
  case class ArrayLength(kind: TypeKind) extends Primitive;

  // type : (buf,el) => buf
  // range: lf,rg <- { BOOL, Ix, Ux, Rx, REF, STR }
  // jvm  : It should call the appropiate 'append' method on StringBuffer
  case class StringConcat(el: TypeKind) extends Primitive

  /** Signals the beginning of a series of concatenations.
   *  On the JVM platform, it should create a new StringBuffer
   */
  case object StartConcat extends Primitive

  /**
   * type: (buf) => STR
   * jvm : It should turn the StringBuffer into a String.
   */
  case object EndConcat extends Primitive

  /** Pretty printer for primitives */
  class PrimitivePrinter(out: PrintWriter) {
    
    def print(s: String): PrimitivePrinter = {
      out.print(s)
      this
    }
    
    def print(o: AnyRef): PrimitivePrinter = print(o.toString())

    def printPrimitive(prim: Primitive) = prim match {
      case Negation(kind) =>
        print("!")

      case Test(op, kind, zero) =>
        print(op).print(kind)

      case Comparison(op, kind) =>
        print(op).print("(").print(kind)
      
    }
  }

  /** This class represents a comparison operation. */
  class ComparisonOp {

    /** Returns a string representation of this operation. */
    override def toString(): String = this match {
      case CMPL => "CMPL"
      case CMP  => "CMP"
      case CMPG => "CMPG"
      case _ => throw new RuntimeException("ComparisonOp unknown case")
    }
  }

  /** A comparison operation with -1 default for NaNs */
  case object CMPL extends ComparisonOp
  
  /** A comparison operation with no default for NaNs */
  case object CMP extends ComparisonOp
  
    /** A comparison operation with +1 default for NaNs */
  case object CMPG extends ComparisonOp


  /** This class represents a test operation. */
  class TestOp {

    /** Returns the negation of this operation. */
    def negate(): TestOp = this match {
        case EQ => NE
        case NE => EQ
        case LT => GE
        case GE => LT
        case LE => GT
        case GT => LE
        case _  => throw new RuntimeException("TestOp unknown case")
    }

    /** Returns a string representation of this operation. */
    override def toString(): String = this match {
        case EQ =>  "EQ"
        case NE =>  "NE"
        case LT =>  "LT"
        case GE =>  "GE"
        case LE =>  "LE"
        case GT =>  "GT"
        case _  => throw new RuntimeException("TestOp unknown case")
    }
  }
  /** An equality test */
  case object EQ extends TestOp
  
  /** A non-equality test */
  case object NE extends TestOp

  /** A less-than test */
  case object LT extends TestOp

  /** A greater-than-or-equal test */
  case object GE extends TestOp

  /** A less-than-or-equal test */
  case object LE extends TestOp

  /** A greater-than test */
  case object GT extends TestOp

  /** This class represents an arithmetic operation. */
  class ArithmeticOp {

    /** Returns a string representation of this operation. */
    override def toString(): String = this match {
      case ADD => "ADD"
      case SUB => "SUB"
      case MUL => "MUL"
      case DIV => "DIV"
      case REM => "REM"
      case NOT => "NOT"
      case _   => throw new RuntimeException("ArithmeticOp unknown case")
    }
  }

  /** An arithmetic addition operation */
  case object ADD extends ArithmeticOp

  /** An arithmetic subtraction operation */
  case object SUB extends ArithmeticOp

  /** An arithmetic multiplication operation */
  case object MUL extends ArithmeticOp
  
  /** An arithmetic division operation */
  case object DIV extends ArithmeticOp

  /** An arithmetic remainder operation */
  case object REM extends ArithmeticOp
  
  /** Bitwise negation. */
  case object NOT extends ArithmeticOp

  /** This class represents a shift operation. */
  class ShiftOp {

    /** Returns a string representation of this operation. */
    override def toString(): String = this match {
      case LSL =>  "LSL"
      case ASR =>  "ASR"
      case LSR =>  "LSR"
      case _  => throw new RuntimeException("ShitOp unknown case")
    }
  }
  
  /** A logical shift to the left */
  case object LSL extends ShiftOp

  /** An arithmetic shift to the right */
  case object ASR extends ShiftOp

  /** A logical shift to the right */
  case object LSR extends ShiftOp

  /** This class represents a logical operation. */
  class LogicalOp {

    /** Returns a string representation of this operation. */
    override def toString(): String = this match {
      case AND => return "AND"
      case OR  => return "OR"
      case XOR => return "XOR"
      case _  => throw new RuntimeException("LogicalOp unknown case")
    }
  }
  
  /** A bitwise AND operation */
  case object AND extends LogicalOp

  /** A bitwise OR operation */
  case object OR extends LogicalOp

  /** A bitwise XOR operation */
  case object XOR extends LogicalOp
}