-----------------------------------------------------------------------
-- Project: Bluespec

-- File: ENotAlwaysReady.bs

-- Author : Amit Grover      <amit@noida.interrasystems.com>

-- Description: This testcase triggers the ENotAlwaysReady error of the bluespec
-- compiler (Method not always ready {identifier})
--
-- Generates error when verilog code is requested for mkGCD
-----------------------------------------------------------------------


package ENotAlwaysReady () where

-- import Int

interface GCD =
    start  :: Int 32 -> Int 32 -> Action
    result :: Int 32

{-# properties mkGCD = {
          alwaysReady
}#-}

mkGCD :: Module GCD
mkGCD =
    module
        x :: Reg (Int 32)
        x <- mkRegU

        y :: Reg (Int 32)
        y <- mkReg 0

        rules
          "Swap":
            when x > y, y /= 0
              ==> action
                      x := y
                      y := x

          "Subtract":
            when x <= y, y /= 0
              ==> action
                      y := y - x

        interface
            start ix iy = action
                              x := ix
                              y := iy
                          when y == 0
            result = x when y == 0