Does somebody know what Ubuntu software is impacted by the lack of a complete set of CMOV instructions in the processor? (e.g. only impacts kernel vs impacts X11 directly, etc).
In the pre-installation manual of 12.04 I found the following:
Where references 2 and 3 point to:
However, Ubuntu precise will not run on i586 or earlier processors. Despite the architecture name "i386", support for actual 80386 processors (and their clones) was dropped with the Sarge (r3.1) release of Debian. (No version of Linux has ever supported the 286 or earlier chips in the series.) Support for i586 and lower processors, as well as for i686 processors without the cmov instruction, was dropped in Ubuntu 10.10. Most i686 and later processors are still supported.
This talks about dropping support for the i486, introduced in 1989 and not about the i686 (AMD K6-2) without a complete set of CMOV instructions.
 We have long tried to avoid this, but in the end it was necessary due a unfortunate series of issues with the compiler and the kernel, starting with an bug in the C++ ABI provided by GCC. You should still be able to run Ubuntu on actual 80386 processors if you compile your own kernel and compile all packages from source, but that is beyond the scope of this manual.
 Many Ubuntu packages will actually run slightly faster on modern computers as a positive side effect of dropping support for these old chips. The i486, introduced in 1989, has three opcodes (bswap, cmpxchg, and xadd) which the i386, introduced in 1986, did not have. Previously, these could not be easily used by most Ubuntu packages; now they can.
Does somebody know what Ubuntu software is impacted by the lack of a complete set of CMOV instructions in the processor?