hi guys, i would like to know where can I find some docs "intel/amd" about operand size and how much clock cicle that operand takes.
as my english is so poor I´m trying to have a help with this forum
my question is something like that:
wich is better?
mov eax, _xxx_handler
call eax
----- or -----
call _xxx_handler
?
I saw, don´t know where that call addr takes about 20 cicles os clock
and call reg, takes only 2-4 bytes
is that right ?
operand sizes and clock cicle.
The second, in about any case, since it's a fixed jump. The first might be seen as an unpredictable jump and in worst-case could cause a pipeline flush, making for about 30 cycles of delay on a NetBurst-cpu.
Instructions don't have a cycle count anymore on current machines, they have, at best, a cycle latency. They're too unpredictable and unreliable to use for any sort of instruction ordering. Why do you care about sub-nanosecond offsets by the way?
Instructions don't have a cycle count anymore on current machines, they have, at best, a cycle latency. They're too unpredictable and unreliable to use for any sort of instruction ordering. Why do you care about sub-nanosecond offsets by the way?
- kataklinger
- Member
- Posts: 381
- Joined: Fri Nov 04, 2005 12:00 am
- Location: Serbia
- Combuster
- Member
- Posts: 9301
- Joined: Wed Oct 18, 2006 3:45 am
- Libera.chat IRC: [com]buster
- Location: On the balcony, where I can actually keep 1½m distance
- Contact:
For AMD: the top two hits at google: http://www.google.nl/search?client=fire ... gle+zoeken