Il 08/05/2013 17:44, Torbjorn Granlund ha scritto:
> Paolo Bonzini writes:
>
> I think that would be faster on 32-bit hosts, truncs are cheap.
>
> And slower perhaps on 64-bit hosts, at least for operations where
> additional explicit trunctation will be needed (such as before
> comparisions
Paolo Bonzini writes:
I think that would be faster on 32-bit hosts, truncs are cheap.
And slower perhaps on 64-bit hosts, at least for operations where
additional explicit trunctation will be needed (such as before
comparisions and after right shifts).
> There could be a disadvantage of t
Il 08/05/2013 00:56, Torbjorn Granlund ha scritto:
> The current ppc gen_op_cmp generates a long sequence of instructions,
> using a plain series of three disjoint compares.
>
> It is possible to compute the 3 result bits more cleverly. Below is a
> possible replacement gen_op_cmp. (It is tested
The current ppc gen_op_cmp generates a long sequence of instructions,
using a plain series of three disjoint compares.
It is possible to compute the 3 result bits more cleverly. Below is a
possible replacement gen_op_cmp. (It is tested by booting GNU/Linux
ppx64, but not much more than that.)
S
