Quadruple-precision softfloat, coding style improvements. Details below…
Highlights:
- completed double-precision support
- added quadruple-precision support
- added SPARC quadruple-precision wrappers
- added doxygen comments
- corrected and unified coding style
Current state of the softfloat library:
Support for single, double and quadruple precision is currently almost complete (apart from power, square root, complex multiplication and complex division) and provides the same set of features (i.e. the support for all three precisions is now aligned). In order to extend softfloat library consistently, addition of quadruple precision was done in the same spirit as already existing single and double precision written by Josef Cejka in 2006 - that is relaxed standard-compliance for corner cases while mission-critical code sections heavily inspired by the widely used softfloat library written by John R. Hauser (although I personally think it would be more appropriate for HelenOS to use something less optimized, shorter and more readable).
Most of the quadruple-precision code is just an adapted double-precision code to work on 128-bit variables. That means if there is , or some defect in single or double-precision code, it is most likely also in the quadruple-precision code. Please note that quadruple-precision functions are currently not tested - it is challenging task for itself, especially when the ports that use them are either not finished (mips64) or badly supported by simulators (sparc64). To test whole softfloat library, one would probably have to either write very non-trivial native tester, or use some existing one (e.g. TestFloat from J. R. Hauser) and port it to HelenOS (or rip the softfloat library out of HelenOS and test it on a host system). At the time of writing this, the code dependent on quadruple-precision functions (on mips64 and sparc64) is just a libposix strtold() function (and its callers, most notably scanf backend).
