specific code path.

improve performance on Atom and P4.

tested, because kernel is not in shape to handle it *yet*. The code is
committed mostly to stimulate the kernel development.

(most restrictive about r2 and r13 usage).

Other Intel processors +5%, Opteron -2%.

for more details.

update commentary...

ABI and binutils.

PR: 2335

Modest improvement coefficients mean that code already had some
parallelism and there was not very much room for improvement. Special
thanks to Ted Krovetz for benchmarking the code with such patience.

ARM assembler modules.

opcodes detected in executable segment" error.

be done, it's definitely not the way to do it. So far answer to the
question was to ./config -Wa,--noexecstack (adopted by RedHat).