Method: MicroCisc::Compile::Instruction#validate_immediate

Defined in:

lib/micro_cisc/compile/instruction.rb

#validate_immediate(value, index) ⇒ Object

# File 'lib/micro_cisc/compile/instruction.rb', line 236

def validate_immediate(value, index)
  width = @bit_width
  width = width / 2 if @operation == 'copy' && @source_is_mem && @dest_is_mem
  if index == 0 && @source_is_mem || index == 1 && @dest_is_mem
    min = 0
    max = (1 << width) - 1
  else
    magnitude = 1 << (width - 1)
    min = magnitude * -1
    max = magnitude - 1
  end
  if (value < min || value > max)
    signed = @source_is_mem ? 'unsigned' : 'signed'
    raise ArgumentError, "Immediate max bits is #{width} #{signed}; value must be between #{min} and #{max} instead of #{value}"
  end
end