SwiftFloatingPointTypes.py

# ===--- SwiftFloatingPointTypes.py ------------------*- coding: utf-8 -*-===//
#
# This source file is part of the Swift.org open source project
#
# Copyright (c) 2014 - 2017 Apple Inc. and the Swift project authors
# Licensed under Apache License v2.0 with Runtime Library Exception
#
# See https://swift.org/LICENSE.txt for license information
# See https://swift.org/CONTRIBUTORS.txt for the list of Swift project authors


# returns (lower, upper) exclusive bounds for the integer values
# that can be stored into a float
defgetFtoIBounds(floatBits, intBits, signed):
floatTy=floating_point_bits_to_type()[floatBits]
sigBits=floatTy.explicit_significand_bits
ifnotsigned:
return (-1, 1<<intBits)
upper=1<< (intBits-1)
ifintBits<=sigBits:
return (-upper-1, upper)
ulp=1<< (intBits-sigBits)
return (-upper-ulp, upper)


classSwiftFloatType(object):

def__init__(self, name, cFuncSuffix, significandBits, exponentBits,
significandSize, totalBits):
self.stdlib_name=name
self.cFuncSuffix=cFuncSuffix
self.significand_bits=significandBits
self.significand_size=significandSize
self.exponent_bits=exponentBits
self.explicit_significand_bits=significandBits+1
self.bits=totalBits


deffloating_point_bits_to_type():
return {
16: SwiftFloatType(name="Float16", cFuncSuffix="f", significandBits=10,
exponentBits=5, significandSize=16, totalBits=16),
32: SwiftFloatType(name="Float", cFuncSuffix="f", significandBits=23,
exponentBits=8, significandSize=32, totalBits=32),
64: SwiftFloatType(name="Double", cFuncSuffix="", significandBits=52,
exponentBits=11, significandSize=64, totalBits=64),
80: SwiftFloatType(name="Float80", cFuncSuffix="l", significandBits=63,
exponentBits=15, significandSize=64, totalBits=80),
 }


defall_floating_point_types():
returnfloating_point_bits_to_type().values()