module Accelerator.SM86.NumericSemantics

family SM86MultiFunction : Type 0
-- SASS MUFU.COS: cosine of the source, radians.
constructor SM86Cosine
-- SASS MUFU.SIN: sine of the source, radians.
constructor SM86Sine
-- SASS MUFU.EX2: two raised to the source.
constructor SM86ExponentialBase2
-- SASS MUFU.LG2: the base-2 logarithm of the source.
constructor SM86LogarithmBase2
-- SASS MUFU.RCP: one divided by the source.
constructor SM86Reciprocal
-- SASS MUFU.RSQ: one divided by the square root of the source.
constructor SM86ReciprocalSquareRoot
-- SASS MUFU.SQRT: the square root of the source.
constructor SM86SquareRoot
-- SASS MUFU.TANH: the hyperbolic tangent of the source.
constructor SM86HyperbolicTangent

end-family

family SM86FloatExtremum : Type 0
-- SASS FMNMX with PT: the smaller of the two operands.
constructor SM86FloatMinimum
-- SASS FMNMX with !PT: the larger of the two operands.
constructor SM86FloatMaximum

end-family

family SM86NumericOperation : Type 0
constructor SM86NumericMultiFunction
field unrestricted sm86NumericMultiFunction : (family SM86MultiFunction)
constructor SM86NumericFloatExtremum
field unrestricted sm86NumericFloatExtremum : (family SM86FloatExtremum)
constructor SM86NumericFloatNegate

end-family

def sm86MultiFunctionOpcode =
  (bytes 8 3)

def sm86FloatExtremumOpcode =
  (bytes 9 2)

def sm86FloatNegateOpcode =
  (bytes 33 2)

def sm86MultiFunctionSelector =
  (lambda unrestricted function : (family SM86MultiFunction) .
    (eliminate
      SM86MultiFunction
      (lambda unrestricted value : (family SM86MultiFunction) . Byte)
      function
      (branch SM86Cosine . (byte 0))
      (branch SM86Sine . (byte 4))
      (branch SM86ExponentialBase2 . (byte 8))
      (branch SM86LogarithmBase2 . (byte 12))
      (branch SM86Reciprocal . (byte 16))
      (branch SM86ReciprocalSquareRoot . (byte 20))
      (branch SM86SquareRoot . (byte 32))
      (branch SM86HyperbolicTangent . (byte 36))))

def sm86FloatExtremumDescriptor =
  (lambda unrestricted extremum : (family SM86FloatExtremum) .
    (eliminate
      SM86FloatExtremum
      (lambda unrestricted value : (family SM86FloatExtremum) . Bytes)
      extremum
      (branch SM86FloatMinimum . (bytes 0 0 128 3))
      (branch SM86FloatMaximum . (bytes 0 0 128 7))))

def sm86NumericOperationOpcode =
  (lambda unrestricted operation : (family SM86NumericOperation) .
    (eliminate
      SM86NumericOperation
      (lambda unrestricted value : (family SM86NumericOperation) . Bytes)
      operation
      (branch SM86NumericMultiFunction function . sm86MultiFunctionOpcode)
      (branch SM86NumericFloatExtremum extremum . sm86FloatExtremumOpcode)
      (branch SM86NumericFloatNegate . sm86FloatNegateOpcode)))

def sm86NumericOperationDescriptor =
  (lambda unrestricted operation : (family SM86NumericOperation) .
    (eliminate
      SM86NumericOperation
      (lambda unrestricted value : (family SM86NumericOperation) . Bytes)
      operation
      (branch
        SM86NumericMultiFunction
        function
        .
        (bytes-cons (sm86MultiFunctionSelector function) b""))
      (branch SM86NumericFloatExtremum extremum . (sm86FloatExtremumDescriptor extremum))
      (branch SM86NumericFloatNegate . (bytes 255 0 0 128 1))))