On Wed, Oct 07, 2015 at 08:46:30PM +1100, Richard Henderson wrote: > On 10/02/2015 10:24 PM, James Hogan wrote: > > Extend MIPS movcond implementation to support the SELNEZ/SELEQZ > > instructions introduced in MIPS r6 (where MOVN/MOVZ have been removed). > > > > Whereas the "MOVN/MOVZ rd, rs, rt" instructions have the following > > semantics: > > rd = [!]rt ? rs : rd > > > > The "SELNEZ/SELEQZ rd, rs, rt" instructions are slightly different: > > rd = [!]rt ? rs : 0 > > > > First we ensure that if one of the movcond input values is zero that it > > comes last (we can swap the input arguments if we invert the condition). > > This is so that it can exactly match one of the SELNEZ/SELEQZ > > instructions and avoid the need to emit the other one. > > > > Otherwise we emit the opposite instruction first into a temporary > > register, and OR that into the result: > > SELNEZ/SELEQZ TMP1, v2, c1 > > SELEQZ/SELNEZ ret, v1, c1 > > OR ret, ret, TMP1 > > > > Which does the following: > > ret = cond ? v1 : v2 > > > > Signed-off-by: James Hogan<james.ho...@imgtec.com> > > Cc: Richard Henderson<r...@twiddle.net> > > Cc: Aurelien Jarno<aurel...@aurel32.net> > > Reviewed-by: Richard Henderson <r...@twiddle.net>
Thanks for the reviewing!
>
>
> > { INDEX_op_brcond_i32, { "rZ", "rZ" } },
> > +#if !use_mips32r6_instructions
> > { INDEX_op_movcond_i32, { "r", "rZ", "rZ", "rZ", "0" } },
> > +#else
> > + { INDEX_op_movcond_i32, { "r", "rZ", "rZ", "rZ", "rZ" } },
> > +#endif
>
>
> The only thing I'd change is preferring positive tests to negative ones. So
> swap the order of these lines, and the sense of the #if.
No problem. Shall I do a full resend for that, or can it be fixed up by
whoever applies?
Cheers
James
>
> Leon, do you want to take this as a mips maintainer, or shall I as tcg
> maintainer?
>
>
> r~
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