Class: Flt::CDCFormat

Inherits:

BinaryFormat

• Object
• FormatBase
• FieldsInBitsFormatBase
• BinaryFormat
• Flt::CDCFormat

Defined in:

lib/float-formats/formats.rb

Overview

CDC 6600/7600 Byte endianness is arbitrary, since these machines were word-addressable, in 60-bit words, but the two words used in double precision numbers are in big endian order TO DO: apply this: The exponent encoded value 1023 is used for NaN The exponent encoded value 0 is used for underflow The exponent encoded value 2047 is used for overflow

The exponent needs special treatment, because instead of excess encoding, which is equivalent to two’s complement followed by sign bit reversal, one’s complement followed by sign bit reversal is used, which is equivalent to use a bias diminished by one for negative exponents. Note that the exponent encoded value that equals the bias is not used (is used as a NaN indicator)

Constant Summary

Constants included from Flt

APPLE, IEEE_128, IEEE_128_BE, IEEE_DEC128, IEEE_DEC32, IEEE_DEC64, IEEE_DOUBLE, IEEE_D_BE, IEEE_EXTENDED, IEEE_HALF, IEEE_H_BE, IEEE_QUAD, IEEE_Q_BE, IEEE_SINGLE, IEEE_S_BE, IEEE_X_BE, IEEE_binaryx, RPL, RPL_X

Instance Attribute Summary

Attributes inherited from FormatBase

#exponent, #sign, #significand

Class Method Summary

• .decode_exponent(ee, mode) ⇒ Object
• .encode_exponent(e, mode) ⇒ Object

  :nodoc:.

Methods inherited from BinaryFormat

define, pack, radix, radix_power, total_bits, total_bytes, unpack

Methods inherited from FieldsInBitsFormatBase

fields_radix, pack_fields, unpack_fields

Methods inherited from FormatBase

#<=>, arithmetic, arithmetic_type, bias, canonicalized, context, #convert_to, decimal_digits_necessary, decimal_digits_stored, decimal_max_exp, decimal_min_exp, define, endianness, epsilon, #form_class, #fp_format, from, from_bits, from_bits_text, from_bytes, from_hex, from_number, from_text, gradual_underflow?, half_epsilon, #infinite?, infinity, #initialize, join, max_value, maximum_integral_significand, min_normalized_value, min_value, minimum_normalized_integral_significand, #minus, minus_sign_value, nan, #nan?, #next_minus, #next_plus, #normal?, num, num_class, numerals_conversion, pack_fields_hash, radix_log, radix_log10, radix_max_exp, radix_min_exp, radix_power, rounding_mode, sign_from_unit, sign_to_unit, #split, strict_epsilon, #subnormal?, switch_sign_value, #to, #to_a, #to_bits, #to_bits_text, #to_bytes, #to_hex, #to_num, #to_text, #ulp, unpack_fields_hash, zero, #zero?

Methods included from Flt

#*, #+, #-, #-@, #/, bcd2dpd, bitnot, convert_bytes, dbl_from_float, dbl_from_text, dbl_to_float, define, dpd2bcd, dpd_to_hexbcd, float_bin, float_dec, float_from_integral_sign_significand_exponent, float_from_integral_significand_exponent, float_shortest_dec, float_significant_dec, float_to_integral_sign_significand_exponent, float_to_integral_significand_exponent, hex_from_float, hex_to_float, hexbcd_to_dpd, sgl_from_float, sgl_from_text, sgl_to_float

Constructor Details

This class inherits a constructor from Flt::FormatBase

Class Method Details

.decode_exponent(ee, mode) ⇒ Object

# File 'lib/float-formats/formats.rb', line 343

def self.decode_exponent(ee,mode)
  e = super
  e += 1 if e<0
  e
end

.encode_exponent(e, mode) ⇒ Object

:nodoc:

# File 'lib/float-formats/formats.rb', line 338

def self.encode_exponent(e,mode)
  ee = super
  ee -= 1 if e<0
  ee
end