[Valgrind-developers] x86-64 features

[Nicholas N. <nj...@ca...>]

Hi,

I was just leafing through the Intel docs for their new AMD64, er, IA32e
processors:
www.intel.com/technology/64bitextensions/index.htm?iid=techtrends+spotlight_64bit

A couple of things caught my eye:

  - we now have explicit rip-relative addressing (section 1.4.2.6).
Interesting, although I'm not sure what it will be useful for.

  - segment registers are being demoted.  In 64-bit mode, they are
"generally (but not completely) disabled".  Roughly speaking, it seems
only %fs and %gs do something in 64-bit mode, although there are various
caveats.  See section 1.6.4.

N