This facilitates "universal" builds, ones that target multiple
architectures, e.g. ARMv5 through ARMv7. See commentary in
Configure for details.
Reviewed-by: NArd Biesheuvel <ard.biesheuvel@linaro.org>
Reviewed-by: NMatt Caswell <matt@openssl.org>

indent will not alter them when reformatting comments
Reviewed-by: NRich Salz <rsalz@openssl.org>
Reviewed-by: NMatt Caswell <matt@openssl.org>

Reviewed-by: NTim Hudson <tjh@openssl.org>

Reviewed-by: NAndy Polyakov <appro@openssl.org>

Reviewed-by: NRich Salz <rsalz@openssl.org>

RT: 2835
Reviewed-by: NDr. Stephen Henson <steve@openssl.org>

This ensures high performance is situations when assembler supports
AVX2, but not AD*X.

Pointer out and suggested by: Ard Biesheuvel.

algorithm suggested in following paper:

Câmara, D.; Gouvêa, C. P. L.; López, J. & Dahab, R.: Fast Software
Polynomial Multiplication on ARM Processors using the NEON Engine.

http://conradoplg.cryptoland.net/files/2010/12/mocrysen13.pdf

This also eliminates code duplication between x86_64-mont and x86_64-mont
and optimizes even original non-MULX code.

PR: 3189
Submitted by: Oscar Ciurana

rsaz_exp.c: harmonize line terminating;
asm/rsaz-*.pl: minor optimizations.

Latest MIPS ISA specification declared 'branch likely' instructions
obsolete. To makes code future-proof replace them with equivalent.

RT: 2582, 2850

Improve RSA sing performance by 20-30% by:
- switching from floating-point to integer conditional moves;
- daisy-chaining sqr-sqr-sqr-sqr-sqr-mul sequences;
- using MONTMUL even during powers table setup;

PR: 3074

eliminating them as dead code.

Both volatile and "memory" are used because of some concern that the compiler
may still cache values across the asm block without it, and because this was
such a painful debugging session that I wanted to ensure that it's never
repeated.