Some hardware, like i965, doesn't support group sizes greater than 32. In that case, we can reduce the destination size of the ballot intrinsic, which will simplify our code generation. --- v2: Just change the intrinsic size, and don't add a new intrinsic (Connor)
src/compiler/nir/nir.h | 2 ++ src/compiler/nir/nir_opt_intrinsics.c | 18 ++++++++++++++++++ src/intel/compiler/brw_compiler.c | 1 + 3 files changed, 21 insertions(+) diff --git a/src/compiler/nir/nir.h b/src/compiler/nir/nir.h index 1e2d7d3cf6..5518807b0b 100644 --- a/src/compiler/nir/nir.h +++ b/src/compiler/nir/nir.h @@ -1842,6 +1842,8 @@ typedef struct nir_shader_compiler_options { */ bool use_interpolated_input_intrinsics; + unsigned max_subgroup_size; + unsigned max_unroll_iterations; } nir_shader_compiler_options; diff --git a/src/compiler/nir/nir_opt_intrinsics.c b/src/compiler/nir/nir_opt_intrinsics.c index 0358680aae..d30c1cf6bb 100644 --- a/src/compiler/nir/nir_opt_intrinsics.c +++ b/src/compiler/nir/nir_opt_intrinsics.c @@ -62,6 +62,24 @@ opt_intrinsics_impl(nir_function_impl *impl) replacement = nir_imm_int(&b, NIR_TRUE); break; } + case nir_intrinsic_ballot: { + assert(b.shader->options->max_subgroup_size != 0); + if (b.shader->options->max_subgroup_size > 32 || + intrin->dest.ssa.bit_size <= 32) + continue; + + nir_intrinsic_instr *ballot = + nir_intrinsic_instr_create(b.shader, nir_intrinsic_ballot); + nir_ssa_dest_init(&ballot->instr, &ballot->dest, 1, 32, NULL); + ballot->src[0] = intrin->src[0]; + + nir_builder_instr_insert(&b, &ballot->instr); + + replacement = nir_pack_64_2x32_split(&b, + &ballot->dest.ssa, + nir_imm_int(&b, 0)); + break; + } default: break; } diff --git a/src/intel/compiler/brw_compiler.c b/src/intel/compiler/brw_compiler.c index 397c8cccf9..b910fcbc3d 100644 --- a/src/intel/compiler/brw_compiler.c +++ b/src/intel/compiler/brw_compiler.c @@ -57,6 +57,7 @@ static const struct nir_shader_compiler_options scalar_nir_options = { .lower_unpack_snorm_4x8 = true, .lower_unpack_unorm_2x16 = true, .lower_unpack_unorm_4x8 = true, + .max_subgroup_size = 64, /* FIXME */ .max_unroll_iterations = 32, }; -- 2.13.0 _______________________________________________ mesa-dev mailing list mesa-dev@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/mesa-dev