Subversion Repositories openrisc_2011-10-31

        TestFloat software tests for floating point operations

From http://www.jhauser.us/arithmetic/TestFloat.html

     TestFloat is a program for testing whether a computer's floating-point 
     conforms to the IEC/IEEE Standard for Binary Floating-point Arithmetic. 
     TestFloat works by comparing the behavior of the machine's floating-point 
     with that of the SoftFloat software implementation of floating-point.

At present only the single precision floating point capability of the software
is used to test the OpenRISC's FPU.

The main loop of the applications in TestFloat have been modified so they do
not rely on input when executed, rather are hard-coded to run all the tests
they possibly can.

All of the output functions (fputs, putc, fprintf) have been replaced with 
versions available in the OR1K support C library.

The software included here also includes the SoftFloat library, which is
is required to test the hardware FPU. 

See http://www.jhauser.us/arithmetic/SoftFloat.html for more information on 
SoftFloat.

The or1ksim simulator actually implements its single precision floating point
using functions from SoftFloat (see the softfloat/ path in the or1ksim project)
so potentially any non-standard behavior of the floating point unit in or1ksim 
will not be picked up by this test (as TestFloat uses SoftFloat itself to check
against the hardware/system results.) However, TestFloat comes with a different
implementation of the IEEE 754 compliant conversion and arithmetic functions to
test SoftFloat against, hopefully picking up any inconsistencies that exist.

Note that the bits64 version of SoftFloat's library is included here. It is 
not a problem for all of the current OR1K GCC implementations to handle 64-bit
data types.

The file layout of SoftFloat and TestFloat, in their distributions, has been
discarded and all the required files have been included in this path.

testfloat is run during the standard check that can be run after compilation. 
By default only the testfloat program will be run (not testsoftfloat). 
testsoftfloat will, actually, be compiled and be under 
testsuite/test-code-or1k/testfloat and can be run from where if desired.


Julius Baxter, August 3 2010