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