Subversion Repositories ssbcc

# Copyright 2014, Sinclair R.F., Inc.

def push24(ad):

  """

  User-defined macro to push a 24 bit value onto the data stack so that the LSB

  is deepest in the data stack and the MSB is at the top of the data stack.

  Usage:

    .push24(v)

  where

    v           is a 24-bit value, a constant, or an evaluated expression\n

  The effect is to push v%0x100, int(v/2**8)%0x100, and int(v/2**16)%0x100 onto

  the data stack.\n

  ( - u_LSB u u_MSB )

  """

  # Add the macro to the list of recognized macros.

  ad.AddMacro('.push24', 3, [ ['','singlevalue','symbol'] ]);

  # Define the macro functionality.

  def emitFunction(ad,fp,argument):

    argument = argument[0];

    v = ad.Emit_IntegerValue(argument);

    if not (-2**23 <= v < 2**24):

      raise asmDef.AsmException('Argument "%s" should be a 24-bit integer at %s' % (argument['value'],argument['loc'],));

    printString = argument['value'] if type(argument['value']) == str else '0x%04X' % (v % 2**24);

    for ix in range(3-1):

      ad.EmitPush(fp,v%0x100,'');

      v >>= 8;

    ad.EmitPush(fp,v%0x100,'.push24(%s)' % printString);

  ad.EmitFunction['.push24'] = emitFunction;