Reviewed-by: Roland Scheidegger <srol...@vmware.com> As for b2i I'm not really convinced using INEG is preferable there. Generally I'd favor logic ops over arithmetic any day. I suppose backend probably need to try to recognize such patterns anyway for best performance (so that for instance things like b2i->i2b should be no-ops), and I just don't see that INEG using AND instead would help much there in general. But I don't really know...
Roland Am 11.05.2015 um 20:38 schrieb Ilia Mirkin: > Could any of the Gallium folk R-b this? It's been this way since Bryan > Cain introduced it... I don't think that there was a USNE/etc variant > at the time. > > Also, what do people think of making b2i do INEG instead of AND? That > should allow implementations to fold the neg into instructions that > support it... > > On Thu, May 7, 2015 at 12:44 AM, Jason Ekstrand <ja...@jlekstrand.net> wrote: >> I know nothing about TGSI but this looks perfectly reasonable to me. >> >> Reviewed-by: Jason Ekstrand <jason.ekstr...@intel.com> >> >> On Wed, May 6, 2015 at 8:33 PM, Ilia Mirkin <imir...@alum.mit.edu> wrote: >>> i2b has to work for all integers, not just 1. INEG would not necessarily >>> result with all bits set, which is something that other operations can >>> rely on by e.g. using AND (or INEG for b2i). >>> >>> Signed-off-by: Ilia Mirkin <imir...@alum.mit.edu> >>> --- >>> >>> Found by observation. Noticed a weird pattern in the generated code, >>> which led up to this. >>> >>> src/mesa/state_tracker/st_glsl_to_tgsi.cpp | 2 +- >>> 1 file changed, 1 insertion(+), 1 deletion(-) >>> >>> diff --git a/src/mesa/state_tracker/st_glsl_to_tgsi.cpp >>> b/src/mesa/state_tracker/st_glsl_to_tgsi.cpp >>> index 93671ba..8a591b9 100644 >>> --- a/src/mesa/state_tracker/st_glsl_to_tgsi.cpp >>> +++ b/src/mesa/state_tracker/st_glsl_to_tgsi.cpp >>> @@ -1941,7 +1941,7 @@ glsl_to_tgsi_visitor::visit(ir_expression *ir) >>> break; >>> case ir_unop_i2b: >>> if (native_integers) >>> - emit(ir, TGSI_OPCODE_INEG, result_dst, op[0]); >>> + emit(ir, TGSI_OPCODE_USNE, result_dst, op[0], >>> st_src_reg_for_int(0)); >>> else >>> emit(ir, TGSI_OPCODE_SNE, result_dst, op[0], >>> st_src_reg_for_float(0.0)); >>> break; >>> -- >>> 2.3.6 >>> >>> _______________________________________________ >>> mesa-dev mailing list >>> mesa-dev@lists.freedesktop.org >>> https://urldefense.proofpoint.com/v2/url?u=http-3A__lists.freedesktop.org_mailman_listinfo_mesa-2Ddev&d=AwIGaQ&c=Sqcl0Ez6M0X8aeM67LKIiDJAXVeAw-YihVMNtXt-uEs&r=Vjtt0vs_iqoI31UfJxBl7yv9I2FeiaeAYgMTLKRBc_I&m=O4w34vxMqlqGFay7yc5k7qGagzc6zNfaCipZfxo8cyA&s=SmX-YkZSIqJwQTJEPqGJ_urIagfbgjrmYRNPZwrVf9I&e= >>> > _______________________________________________ > mesa-dev mailing list > mesa-dev@lists.freedesktop.org > https://urldefense.proofpoint.com/v2/url?u=http-3A__lists.freedesktop.org_mailman_listinfo_mesa-2Ddev&d=AwIGaQ&c=Sqcl0Ez6M0X8aeM67LKIiDJAXVeAw-YihVMNtXt-uEs&r=Vjtt0vs_iqoI31UfJxBl7yv9I2FeiaeAYgMTLKRBc_I&m=O4w34vxMqlqGFay7yc5k7qGagzc6zNfaCipZfxo8cyA&s=SmX-YkZSIqJwQTJEPqGJ_urIagfbgjrmYRNPZwrVf9I&e= > > _______________________________________________ mesa-dev mailing list mesa-dev@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/mesa-dev
