On Wed, Sep 28, 2016 at 09:00:51PM -0700, Richard Henderson wrote: > On 09/28/2016 07:07 PM, David Gibson wrote: > > > + tcg_gen_mulu2_i64(t0, t1, cpu_avrl[rA(ctx->opcode)], val); \ > > > > Do you really want to be using an actual mul op, rather than (in << 3) > > + (in << 1)? Obviously working out al the carries correctly will be a > > bit fiddly. > > I think it's fine. Modern hardware will do the double-word multiply in 3-5 > cycles, which is probably equal to what we could do by hand with > shifts.
Fair enough. And it will make for less dicking around with the carry
in and carry out.
--
David Gibson | I'll have my music baroque, and my code
david AT gibson.dropbear.id.au | minimalist, thank you. NOT _the_ _other_
| _way_ _around_!
http://www.ozlabs.org/~dgibson
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