Re: [Qemu-devel] TCG: 128 bit ops?

[Blue Swirl]

On 9/4/08, Aurelien Jarno <address@hidden> wrote:
> On Thu, Sep 04, 2008 at 01:10:39PM +0200, Andreas Färber wrote:
>  > Hello,
>  >
>  > Am I correct in seeing that TCG offers no i128 ops? Would this be useful
>  > to add to TCG, internally reusing the i64/i32 code? ppc needs 128-bit
>  > temporaries for Altivec instructions. It uses a union ppc_avr_t of (among
>  > others) two uint64_t.
>  >
>  > Or should I just use two i64 temporaries with a local macro/helper?
>  > It's not used much in ppc but I thought it might be useful to share with
>  > other architectures.
>  >
>
>
> Currently TCG doesn't support i128 ops, but I also agree it would be
>  nice to have it. I think it can benefits for example to sparc64 which
>  has 128-bit fp support.

I agree that i128 would be useful, though float32/64/80/128 would be
even more so.

Sparc (32 and 64) specifications have included 128 bit float ops since
day one, but so far they haven't been implemented in real CPUs.