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- Introduction
- ============
- This directory contains the version 0.92 test release of the NetWinder
- Floating Point Emulator.
- The majority of the code was written by me, Scott Bambrough It is
- written in C, with a small number of routines in inline assembler
- where required. It was written quickly, with a goal of implementing a
- working version of all the floating point instructions the compiler
- emits as the first target. I have attempted to be as optimal as
- possible, but there remains much room for improvement.
- I have attempted to make the emulator as portable as possible. One of
- the problems is with leading underscores on kernel symbols. Elf
- kernels have no leading underscores, a.out compiled kernels do. I
- have attempted to use the C_SYMBOL_NAME macro wherever this may be
- important.
- Another choice I made was in the file structure. I have attempted to
- contain all operating system specific code in one module (fpmodule.*).
- All the other files contain emulator specific code. This should allow
- others to port the emulator to NetBSD for instance relatively easily.
- The floating point operations are based on SoftFloat Release 2, by
- John Hauser. SoftFloat is a software implementation of floating-point
- that conforms to the IEC/IEEE Standard for Binary Floating-point
- Arithmetic. As many as four formats are supported: single precision,
- double precision, extended double precision, and quadruple precision.
- All operations required by the standard are implemented, except for
- conversions to and from decimal. We use only the single precision,
- double precision and extended double precision formats. The port of
- SoftFloat to the ARM was done by Phil Blundell, based on an earlier
- port of SoftFloat version 1 by Neil Carson for NetBSD/arm32.
- The file README.FPE contains a description of what has been implemented
- so far in the emulator. The file TODO contains a information on what
- remains to be done, and other ideas for the emulator.
- Bug reports, comments, suggestions should be directed to me at
- <[email protected]>. General reports of "this program doesn't
- work correctly when your emulator is installed" are useful for
- determining that bugs still exist; but are virtually useless when
- attempting to isolate the problem. Please report them, but don't
- expect quick action. Bugs still exist. The problem remains in isolating
- which instruction contains the bug. Small programs illustrating a specific
- problem are a godsend.
- Legal Notices
- -------------
- The NetWinder Floating Point Emulator is free software. Everything Rebel.com
- has written is provided under the GNU GPL. See the file COPYING for copying
- conditions. Excluded from the above is the SoftFloat code. John Hauser's
- legal notice for SoftFloat is included below.
- -------------------------------------------------------------------------------
- SoftFloat Legal Notice
- SoftFloat was written by John R. Hauser. This work was made possible in
- part by the International Computer Science Institute, located at Suite 600,
- 1947 Center Street, Berkeley, California 94704. Funding was partially
- provided by the National Science Foundation under grant MIP-9311980. The
- original version of this code was written as part of a project to build
- a fixed-point vector processor in collaboration with the University of
- California at Berkeley, overseen by Profs. Nelson Morgan and John Wawrzynek.
- THIS SOFTWARE IS DISTRIBUTED AS IS, FOR FREE. Although reasonable effort
- has been made to avoid it, THIS SOFTWARE MAY CONTAIN FAULTS THAT WILL AT
- TIMES RESULT IN INCORRECT BEHAVIOR. USE OF THIS SOFTWARE IS RESTRICTED TO
- PERSONS AND ORGANIZATIONS WHO CAN AND WILL TAKE FULL RESPONSIBILITY FOR ANY
- AND ALL LOSSES, COSTS, OR OTHER PROBLEMS ARISING FROM ITS USE.
- -------------------------------------------------------------------------------
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