def pack_decimal64(decimal):
"""Pack an IEEE 754-2008 64-bit decimal floating point number."""
if not decimal.is_finite():
yield _decimal_pack_special(decimal, 8)
return
sign, digits, exponent = decimal.as_tuple()
if len(digits) > 16 or (not -398 <= exponent <= 369):
raise ValueError()
significand = int(''.join(map(str, digits)))
if significand >> 51 == 4:
yield ((sign << 63) | (3 << 61) | ((exponent + 398) << 51) |
(significand & 2251799813685247)).to_bytes(8, 'big')
else:
yield ((sign << 63) | ((exponent + 398) << 53) | significand).to_bytes(
8, 'big')
def pack_decimal32(decimal):
"""Pack an IEEE 754-2008 32-bit decimal floating point number."""
if not decimal.is_finite():
yield _decimal_pack_special(decimal, 4)
return
sign, digits, exponent = decimal.as_tuple()
if len(digits) > 7 or (not -101 <= exponent <= 90):
raise ValueError()
significand = int(''.join(map(str, digits)))
if significand >> 21 == 4:
yield ((sign << 31) | (3 << 29) | ((exponent + 101) << 21) |
(significand & 2097151)).to_bytes(4, 'big')
else:
yield ((sign << 31) | ((exponent + 101) << 23) | significand).to_bytes(
4, 'big')
def pack_decimal64(decimal):
"""Pack an IEEE 754-2008 64-bit decimal floating point number."""
if not decimal.is_finite():
yield _decimal_pack_special(decimal, 8)
return
sign, digits, exponent = decimal.as_tuple()
if len(digits) > 16 or (not -398 <= exponent <= 369):
raise ValueError()
significand = int(''.join(map(str, digits)))
if significand >> 51 == 4:
yield ((sign << 63) | (3 << 61) | ((exponent + 398) << 51) |
(significand & 2251799813685247)).to_bytes(8, 'big')
else:
yield ((sign << 63) | ((exponent + 398) << 53) |
significand).to_bytes(8, 'big')
def pack_decimal32(decimal):
"""Pack an IEEE 754-2008 32-bit decimal floating point number."""
if not decimal.is_finite():
yield _decimal_pack_special(decimal, 4)
return
sign, digits, exponent = decimal.as_tuple()
if len(digits) > 7 or (not -101 <= exponent <= 90):
raise ValueError()
significand = int(''.join(map(str, digits)))
if significand >> 21 == 4:
yield ((sign << 31) | (3 << 29) | ((exponent + 101) << 21) |
(significand & 2097151)).to_bytes(4,'big')
else:
yield ((sign << 31) | ((exponent + 101) << 23) |
significand).to_bytes(4, 'big')
def pack_decimal128(decimal):
"""Pack an IEEE 754-2008 128-bit decimal floating point number."""
if not decimal.is_finite():
yield _decimal_pack_special(decimal, 16)
return
sign, digits, exponent = decimal.as_tuple()
if len(digits) > 34 or (not -6176 <= exponent <= 6111):
raise ValueError()
significand = int(''.join(map(str, digits)))
if significand >> 111 == 4:
yield ((sign << 127) | (3 << 125) | ((exponent + 6176) << 111) |
(significand & 2596148429267413814265248164610047)).to_bytes(
16, byteorder='big')
else:
yield ((sign << 127) | ((exponent + 6176) << 113)
| significand).to_bytes(16, byteorder='big')
def pack_decimal128(decimal):
"""Pack an IEEE 754-2008 128-bit decimal floating point number."""
if not decimal.is_finite():
yield _decimal_pack_special(decimal, 16)
return
sign, digits, exponent = decimal.as_tuple()
if len(digits) > 34 or (not -6176 <= exponent <= 6111):
raise ValueError()
significand = int(''.join(map(str, digits)))
if significand >> 111 == 4:
yield ((sign << 127) | (3 << 125) | ((exponent + 6176) << 111) |
(significand & 2596148429267413814265248164610047)
).to_bytes(16, byteorder='big')
else:
yield ((sign << 127) | ((exponent + 6176) << 113) |
significand).to_bytes(16, byteorder='big')
