Release notes for Linux Kernel VFP support code — The Linux Kernel 5.18.5-gnu-1 documentation

# Release notes for Linux Kernel VFP support code

Date: 20 May 2004

Author: Russell King

This is the first release of the Linux Kernel VFP support code. It provides support for the exceptions bounced from VFP hardware found on ARM926EJ-S.

This release has been validated against the SoftFloat-2b library by John R. Hauser using the TestFloat-2a test suite. Details of this library and test suite can be found at:

> http://www.jhauser.us/arithmetic/SoftFloat.html

The operations which have been tested with this package are:

> - fdiv

> - fsub

> - fadd

> - fmul

> - fcmp

> - fcmpe

> - fcvtd

> - fcvts

> - fsito

> - ftosi

> - fsqrt

All the above pass softfloat tests with the following exceptions:

- fadd/fsub shows some differences in the handling of +0 / -0 results when input operands differ in signs.

- the handling of underflow exceptions is slightly different. If a result underflows before rounding, but becomes a normalised number after rounding, we do not signal an underflow exception.

Other operations which have been tested by basic assembly-only tests are:

> - fcpy

> - fabs

> - fneg

> - ftoui

> - ftosiz

> - ftouiz

The combination operations have not been tested:

> - fmac

> - fnmac

> - fmsc

> - fnmsc

> - fnmul