We already have a lower_negate compiler option, so I think it would be better to add the 1 line of code to lower sub -> neg predicated on !lower_neg to nir_opt_algebraic.
On Mon, Mar 23, 2015 at 8:37 PM, Kenneth Graunke <kenn...@whitecape.org> wrote: > prog_to_nir uses this for OPCODE_SUB. > > Signed-off-by: Kenneth Graunke <kenn...@whitecape.org> > --- > src/mesa/drivers/dri/i965/brw_fs_nir.cpp | 6 ++++++ > 1 file changed, 6 insertions(+) > > diff --git a/src/mesa/drivers/dri/i965/brw_fs_nir.cpp > b/src/mesa/drivers/dri/i965/brw_fs_nir.cpp > index 69f296c..094303f 100644 > --- a/src/mesa/drivers/dri/i965/brw_fs_nir.cpp > +++ b/src/mesa/drivers/dri/i965/brw_fs_nir.cpp > @@ -905,6 +905,12 @@ fs_visitor::nir_emit_alu(nir_alu_instr *instr) > inst->saturate = instr->dest.saturate; > break; > > + case nir_op_fsub: > + case nir_op_isub: > + inst = emit(ADD(result, op[0], negate(op[1]))); > + inst->saturate = instr->dest.saturate; > + break; > + > case nir_op_fmul: > inst = emit(MUL(result, op[0], op[1])); > inst->saturate = instr->dest.saturate; > -- > 2.3.3 > > _______________________________________________ > mesa-dev mailing list > mesa-dev@lists.freedesktop.org > http://lists.freedesktop.org/mailman/listinfo/mesa-dev _______________________________________________ mesa-dev mailing list mesa-dev@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/mesa-dev
