[ltp] Re: How much performance improvement going from 32-bit to 64-bit linux?

[Stefan Monnier]

> It means 8 more visible registers. In 32 bit mode the new registers are
> hidden and used for register remapping. There is no gain in make more
> registers visible unless the compiler is really, really clever.

Not quite true: it's easy for a compiler to make good use of more than
8 registers.  It's actually rather the opposite: it takes a lot of work
for a compiler to egnerate good code using only 8 registers.
So, yes, 16 registers will help the compiler generate good code.

Is the difference larger than the negative impact of using more
memory to store each pointer?  That completely depends on the specific
application and the way you compile and use it.

All in all, the most likely outcome is that you won't notice
any difference unless you go and measure it precisely.


        Stefan