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Notice: This project has been migrated to GitHub. https://github.com/coder0xff/QPFloat

QPFloat (GPL 3.0)

For high-precision mathematics, the Quadruple-Precision Floating Point library (QPFloat) emulates the IEEE 754 2008 binary128 on x86, and x64 (and probably any other little-endian platform) using integer arithmetic and bit manipulation. It contains a native C++ and assembler implementation, and a .Net C++/CLI implementation.

Features

Much effort has been put into supporting a full feature set, including optimized transcendental functions and string conversion to full precision.

Standard operations

• addition, subtraction, multiplication, division
• Min, Max, Abs, Ceiling, Floor, Round, Truncate, Fraction
• ToString and FromString
• Cast operators to and from native numeric data types

Numeric information

• IsZero
• IsNaN
• IsInfinite
• IsSigned
• IsSubNormal

Transcendental functions

• natural logarithm (Ln), arbitrary-base logarithm (Log)
• exponentiation (Exp)
• power function (Pow)
• Sin, Cos, Tan
• ASin, ACos, ATan, ATan2

Miscellaneous features

• Fast! Optimized low level bit manipulation
• Hard coded constant Pi and E to full quadruple precision
• Implemented on little-endian architecture, may or may not work on big-endian???
• Strictly follows IEEE specifications to the extent availabile on Wikipedia.
• Multiple guard bits
• Arithmetic on sub-normals is fully supported.
• Inf, -Inf, and NaN are fully supported.
• round-to-even
• emulates FPU exceptions with enable/disable flags (default: all disabled)

Using

VB.Net, C# users, and C++/CLI

1. Add a reference to Release/QPFloat.dll (x64/Release/QPFloat.dll for x64)
2. Create new variables using System.Quadruple

C++ users

1. Add a reference to QPFloat.dll (x64/Release/QPFloat.dll for x64)
2. include "__float128.h"
3. create new variables using __float128

Compiling

Microsoft Visual C++

• This code base can be compiled with or without /clr (Managed C++) to the compiler.
• If /clr IS used, then this library can be used by C#, VB.Net, and C++/CLI via the type System.Quadruple.
• If /clr IS NOT used, #ifdef _MANAGED has been used to automatically exclude the managed implementation.
• Since extension methods can't be used to add static functions to System.Math, Operations like Abs, Sin, etc are static methods of Quadruple.
• __float128 is the unmanaged (faster) implementation, which is still present even when /clr is used.

Other compilers

• This code uses #ifdef to remove Microsoft specific functionality automatically (#ifdef _MANAGED)
• Though I've not tried, it should be relatively easy to build using other compilers.
• following existing conventions, __float128 is the type proffered by this library.