On Mon, Apr 30, 2018 at 7:18 AM, Iago Toral Quiroga <ito...@igalia.com> wrote:
> Not all bit-sizes may be supported natively in hardware for all operations. > This pass allows drivers to lower such operations to a bit-size that is > actually supported and then converts the result back to the original > bit-size. > > Compiler backends control which operations and wich bit-sizes require > the lowering through a callback function. > > v2: generalize this pass and make it available in NIR core (Rob, Jason) > --- > src/compiler/Makefile.sources | 1 + > src/compiler/nir/meson.build | 1 + > src/compiler/nir/nir.h | 6 ++ > src/compiler/nir/nir_lower_bit_size.c | 127 > ++++++++++++++++++++++++++++++++++ > 4 files changed, 135 insertions(+) > create mode 100644 src/compiler/nir/nir_lower_bit_size.c > > diff --git a/src/compiler/Makefile.sources b/src/compiler/Makefile.sources > index aca9dab476..b5321588be 100644 > --- a/src/compiler/Makefile.sources > +++ b/src/compiler/Makefile.sources > @@ -237,6 +237,7 @@ NIR_FILES = \ > nir/nir_lower_phis_to_scalar.c \ > nir/nir_lower_regs_to_ssa.c \ > nir/nir_lower_returns.c \ > + nir/nir_lower_bit_size.c \ > nir/nir_lower_samplers.c \ > nir/nir_lower_samplers_as_deref.c \ > nir/nir_lower_subgroups.c \ > diff --git a/src/compiler/nir/meson.build b/src/compiler/nir/meson.build > index b28a565d0c..62fe5167d3 100644 > --- a/src/compiler/nir/meson.build > +++ b/src/compiler/nir/meson.build > @@ -144,6 +144,7 @@ files_libnir = files( > 'nir_lower_vec_to_movs.c', > 'nir_lower_wpos_center.c', > 'nir_lower_wpos_ytransform.c', > + 'nir_lower_bit_size.c', > 'nir_metadata.c', > 'nir_move_vec_src_uses_to_dest.c', > 'nir_normalize_cubemap_coords.c', > diff --git a/src/compiler/nir/nir.h b/src/compiler/nir/nir.h > index f3326e6df9..e7f2b145b3 100644 > --- a/src/compiler/nir/nir.h > +++ b/src/compiler/nir/nir.h > @@ -2763,6 +2763,12 @@ bool nir_lower_to_source_mods(nir_shader *shader); > > bool nir_lower_gs_intrinsics(nir_shader *shader); > > +typedef unsigned (*nir_lower_bit_size_callback)(const nir_alu_instr *, > void *); > + > +bool nir_lower_bit_size(nir_shader *shader, > + nir_lower_bit_size_callback callback, > + void *callback_data); > + > typedef enum { > nir_lower_imul64 = (1 << 0), > nir_lower_isign64 = (1 << 1), > diff --git a/src/compiler/nir/nir_lower_bit_size.c > b/src/compiler/nir/nir_lower_bit_size.c > new file mode 100644 > index 0000000000..8e0fd663a1 > --- /dev/null > +++ b/src/compiler/nir/nir_lower_bit_size.c > @@ -0,0 +1,127 @@ > +/* > + * Copyright © 2018 Intel Corporation > + * > + * Permission is hereby granted, free of charge, to any person obtaining a > + * copy of this software and associated documentation files (the > "Software"), > + * to deal in the Software without restriction, including without > limitation > + * the rights to use, copy, modify, merge, publish, distribute, > sublicense, > + * and/or sell copies of the Software, and to permit persons to whom the > + * Software is furnished to do so, subject to the following conditions: > + * > + * The above copyright notice and this permission notice (including the > next > + * paragraph) shall be included in all copies or substantial portions of > the > + * Software. > + * > + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, > EXPRESS OR > + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF > MERCHANTABILITY, > + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT > SHALL > + * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR > OTHER > + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING > + * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER > DEALINGS > + * IN THE SOFTWARE. > + */ > + > +#include "nir_builder.h" > + > +/** > + * Some ALU operations may not be supported in hardware in specific > bit-sizes. > + * This pass allows implementations to selectively lower such operations > to > + * a bit-size that is supported natively and the converts the result back > to > + * the original bit-size. > + */ > +static nir_ssa_def * > +convert_to_bit_size(nir_builder *bld, > + nir_ssa_def *src, > + nir_alu_type type, > + unsigned bit_size) > +{ > + nir_alu_type base_type = nir_alu_type_get_base_type(type); > + nir_alu_type lowered_type = bit_size | base_type; > + > + nir_op opcode = > + nir_type_conversion_op(type, lowered_type, nir_rounding_mode_undef); > + > + return nir_build_alu(bld, opcode, src, NULL, NULL, NULL); > +} > + > +static void > +lower_instr(nir_builder *bld, nir_alu_instr *alu, unsigned bit_size) > +{ > + const nir_op op = alu->op; > + > + bld->cursor = nir_before_instr(&alu->instr); > + > + /* Convert each source to the requested bit-size */ > + nir_ssa_def *srcs[4] = { NULL, NULL, NULL, NULL }; > + const unsigned num_inputs = nir_op_infos[op].num_inputs;' > I don't know that we need the num_inputs temporary > + for (unsigned i = 0; i < num_inputs; i++) { > + nir_ssa_def *src = nir_ssa_for_alu_src(bld, alu, i); > + > + nir_alu_type type = nir_op_infos[op].input_types[i]; > + unsigned type_size = nir_alu_type_get_type_size(type); > Again, I don't think this temporary is needed. > + if (type_size == 0) > + srcs[i] = convert_to_bit_size(bld, src, type, bit_size); > + else > + srcs[i] = src; > + } > + > + /* Emit the lowered ALU instruction */ > + nir_ssa_def *lowered_dst = > + nir_build_alu(bld, op, srcs[0], srcs[1], srcs[2], srcs[3]); > + > + /* Convert result back to the original bit-size */ > + unsigned dst_bit_size = alu->dest.dest.ssa.bit_size; > + nir_alu_type type = nir_op_infos[op].output_type; > + nir_ssa_def *dst = convert_to_bit_size(bld, lowered_dst, type, > dst_bit_size); > + nir_ssa_def_rewrite_uses(&alu->dest.dest.ssa, nir_src_for_ssa(dst)); > +} > + > +static bool > +lower_impl(nir_function_impl *impl, > + nir_lower_bit_size_callback callback, > + void *callback_data) > +{ > + nir_builder b; > + nir_builder_init(&b, impl); > + bool progress = false; > + > + nir_foreach_block(block, impl) { > + nir_foreach_instr_safe(instr, block) { > + if (instr->type == nir_instr_type_alu) { > I'd make this "if (!= alu) continue;" so we can keep the nesting depth down. All my comments are fairly trivial so Reviewed-by: Jason Ekstrand <ja...@jlekstrand.net> > + nir_alu_instr *alu = nir_instr_as_alu(instr); > + assert(alu->dest.dest.is_ssa); > + > + unsigned lower_bit_size = callback(alu, callback_data); > + if (lower_bit_size == 0) > + continue; > + > + assert(lower_bit_size != alu->dest.dest.ssa.bit_size); > + > + lower_instr(&b, alu, lower_bit_size); > + progress = true; > + } > + } > + } > + > + if (progress) { > + nir_metadata_preserve(impl, nir_metadata_block_index | > + nir_metadata_dominance); > + } > + > + return progress; > +} > + > +bool > +nir_lower_bit_size(nir_shader *shader, > + nir_lower_bit_size_callback callback, > + void *callback_data) > +{ > + bool progress = false; > + > + nir_foreach_function(function, shader) { > + if (function->impl) > + progress |= lower_impl(function->impl, callback, callback_data); > + } > + > + return progress; > +} > -- > 2.14.1 > >
_______________________________________________ mesa-dev mailing list mesa-dev@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/mesa-dev