Subversion Repositories ssbcc

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

def pushByte(ad):

  """

  User-defined macro to push a 32 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:

    .pushByte(v,ix)

  where

    v           is a multi-byte value, a constant, or an evaluated expression

    ix          is the index to the byte to push (ix=0 ==> push the LSB, ...)\n

  The effect is to push "(v/2**ix) % 0x10" onto the data stack.\n

  ( - u_byte )

  """

  # Add the macro to the list of recognized macros.

  ad.AddMacro('.pushByte', 1, [

                                ['','singlevalue','symbol'],

                                ['','singlevalue','symbol'],

                              ]);

  # Define the macro functionality.

  def emitFunction(ad,fp,argument):

    v  = ad.Emit_IntegerValue(argument[0]);

    ix = ad.Emit_IntegerValue(argument[1]);

    if ix < 0:

      raise asmDef.AsmException('ix must be non-negative in .pushByte at %s' % argument[1]['loc']);

    v = int(v/2**ix) % 0x100;

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

    printIx    = argument[1]['value'] if type(argument[1]['value']) == str else '0x%X' % argument[1]['value'];

    ad.EmitPush(fp,v,'.pushByte(%s,%s)' % (printValue,printIx,));

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