OpenLibm

OpenLibm is an effort to have a high quality, portable, standalone C mathematical library (libm). It can be used standalone in applications and programming language implementations.

The project was born out of a need to have a good libm for the Julia programming langage that worked consistently across compilers and operating systems, and in 32-bit and 64-bit environments.

Platform support

OpenLibm builds on Linux, Mac OS X, Windows, FreeBSD, and OpenBSD. It builds with both GCC and clang. Although largely tested and widely used on x86 architectures, openlibm also supports ARM and powerPC.

Build instructions

1. Use make to build OpenLibm.
2. Use make USEGCC=1 to build with GCC. This is the default on Linux and Windows.
3. Use make USECLANG=1 to build with clang. This is the default on OS X and FreeBSD.
4. Architectures are auto-detected. Use make ARCH=i386 to force a build for i386. Other supported architectures are i486, i586, and i686. GCC 4.8 is the minimum requirement for correct codegen on older 32-bit architectures.
5. On OpenBSD, you need to install GNU Make (port name: gmake) and a recent version of gcc (tested: 4.9.2), as the default version provided by OpenBSD is too old (4.2.1). If you use OpenBSD's port system for this (port name: gcc), run make CC=egcc to force Make to use the newer gcc.

Acknowledgements

PowerPC support for openlibm was graciously sponsored by IBM.