Re: [Qemu-devel] [PATCH 02/14] tcg: Add INDEX_op_trunc_i32

[Stuart Brady]

On Fri, Mar 21, 2014 at 11:35:12PM +0000, Stuart Brady wrote:
> On Mon, Mar 17, 2014 at 11:37:44AM -0700, Richard Henderson wrote:
> > diff --git a/tcg/README b/tcg/README
> > index f178212..160cbe8 100644
> > --- a/tcg/README
> > +++ b/tcg/README
> > @@ -306,6 +306,11 @@ This operation would be equivalent to
> >  
> >    dest = (t1 & ~0x0f00) | ((t2 << 8) & 0x0f00)
> >  
> > +* trunc_i32 t0, t1, pos
> > +
> > +For 64-bit hosts only, right shift the 64-bit input T1 by POS and
> > +truncate to 32-bit output T0.  Depending on the host, this may be
> > +a simple mov/shift, or may require additional canonicalization.
> 
> Surely trunc_rshift_i64_i32, which is used elsewhere in this patch?

... but not used consistently, so this affects more than just the README.
Forgot to mention that! :-)

> ... or trunc_shr_i64_i32 as we use 'shr' for the existing shift-right op.

Cheers,
Stuart