Subversion Repositories ssbcc

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

def push16(ad):

  """

  User-defined macro to push a 16 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.\n

  Usage:

    .push16(v)

  where

    v           is a 16-bit value, a constant, or an evaluated expression\n

  The effect is to push v%0x100 and int(v/2**8)%0x100 onto the data stack.\n

  ( - u_LSB u u u_MSB )

  """

  # Add the macro to the list of recognized macros.

  ad.AddMacro('.push16', 2, [ ['','singlevalue','symbol'] ]);

  # Define the macro functionality.

  def emitFunction(ad,fp,argument):

    argument = argument[0];

    if argument['type'] == 'value':

      v = argument['value'];

    elif argument['type'] == 'symbol':

      name = argument['value'];

      if not ad.IsSymbol(name):

        raise asmDef.AsmException('Symbol "%s" not recognized at %s' % (argument['value'],argument['loc'],));

      ix = ad.symbols['list'].index(name);

      v = ad.symbols['body'][ix];

      if len(v) != 1:

        raise asmDef.AsmException('Argument can only be one value at %s' % argument['loc']);

      v = v[0];

    else:

      raise asmDef.AsmException('Argument "%s" of type "%s" not recognized at %s' % (argument['value'],argument['type'],argument['loc'],));

    if type(v) != int:

      raise Exception('Program Bug -- value should be an "int"');

    ad.EmitPush(fp,v%0x100,''); v >>= 8;

    printValue = argument['value'] if type(argument['value']) == str else '0x%08X' % argument['value'];

    ad.EmitPush(fp,v%0x100,'.push16(%s)' % printValue);

  ad.EmitFunction['.push16'] = emitFunction;