| # ===--- 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 |
| def getFtoIBounds(floatBits, intBits, signed): |
| floatTy = floating_point_bits_to_type()[floatBits] |
| sigBits = floatTy.explicit_significand_bits |
| if not signed: |
| return (-1, 1 << intBits) |
| upper = 1 << (intBits - 1) |
| if intBits <= sigBits: |
| return (-upper - 1, upper) |
| ulp = 1 << (intBits - sigBits) |
| return (-upper - ulp, upper) |
| |
| |
| class SwiftFloatType(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 |
| |
| |
| def floating_point_bits_to_type(): |
| return { |
| 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), |
| } |
| |
| |
| def all_floating_point_types(): |
| return floating_point_bits_to_type().values() |
