From 9f1411d1ecc0029f4a6697849e657ac7b2a64f94 Mon Sep 17 00:00:00 2001 From: Eric Anholt Date: Thu, 4 Aug 2016 12:42:45 -0700 Subject: [PATCH] nir: Add an IO scalarizing pass using the intrinsic's first_component. vc4 wants to have per-scalar IO load/stores so that dead code elimination can happen on a more granular basis, which it has been doing in the backend using a multiplication by 4 of the intrinsic's driver_location. We can represent it properly in the NIR using the first_component field, though. Reviewed-by: Kenneth Graunke --- src/compiler/Makefile.sources | 1 + src/compiler/nir/nir.h | 1 + src/compiler/nir/nir_lower_io_to_scalar.c | 129 ++++++++++++++++++++++ 3 files changed, 131 insertions(+) create mode 100644 src/compiler/nir/nir_lower_io_to_scalar.c diff --git a/src/compiler/Makefile.sources b/src/compiler/Makefile.sources index a2dd2341885..cfb6359a6f8 100644 --- a/src/compiler/Makefile.sources +++ b/src/compiler/Makefile.sources @@ -203,6 +203,7 @@ NIR_FILES = \ nir/nir_lower_indirect_derefs.c \ nir/nir_lower_io.c \ nir/nir_lower_io_to_temporaries.c \ + nir/nir_lower_io_to_scalar.c \ nir/nir_lower_io_types.c \ nir/nir_lower_passthrough_edgeflags.c \ nir/nir_lower_phis_to_scalar.c \ diff --git a/src/compiler/nir/nir.h b/src/compiler/nir/nir.h index e09cf3b8109..5e527d8add1 100644 --- a/src/compiler/nir/nir.h +++ b/src/compiler/nir/nir.h @@ -2395,6 +2395,7 @@ void nir_lower_alu_to_scalar(nir_shader *shader); void nir_lower_load_const_to_scalar(nir_shader *shader); void nir_lower_phis_to_scalar(nir_shader *shader); +void nir_lower_io_to_scalar(nir_shader *shader, nir_variable_mode mask); void nir_lower_samplers(nir_shader *shader, const struct gl_shader_program *shader_program); diff --git a/src/compiler/nir/nir_lower_io_to_scalar.c b/src/compiler/nir/nir_lower_io_to_scalar.c new file mode 100644 index 00000000000..f2345d58acf --- /dev/null +++ b/src/compiler/nir/nir_lower_io_to_scalar.c @@ -0,0 +1,129 @@ +/* + * Copyright © 2016 Broadcom + * + * 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.h" +#include "nir_builder.h" + +/** @file nir_lower_io_to_scalar.c + * + * Replaces nir_load_input/nir_store_output operations with num_components != + * 1 with individual per-channel operations. + */ + +static void +lower_load_input_to_scalar(nir_builder *b, nir_intrinsic_instr *intr) +{ + b->cursor = nir_before_instr(&intr->instr); + + assert(intr->dest.is_ssa); + + nir_ssa_def *loads[4]; + + for (unsigned i = 0; i < intr->num_components; i++) { + nir_intrinsic_instr *chan_intr = + nir_intrinsic_instr_create(b->shader, intr->intrinsic); + nir_ssa_dest_init(&chan_intr->instr, &chan_intr->dest, + 1, intr->dest.ssa.bit_size, NULL); + chan_intr->num_components = 1; + + nir_intrinsic_set_base(chan_intr, nir_intrinsic_base(intr)); + nir_intrinsic_set_component(chan_intr, nir_intrinsic_component(intr) + i); + /* offset */ + chan_intr->src[0] = intr->src[0]; + + nir_builder_instr_insert(b, &chan_intr->instr); + + loads[i] = &chan_intr->dest.ssa; + } + + nir_ssa_def_rewrite_uses(&intr->dest.ssa, + nir_src_for_ssa(nir_vec(b, loads, + intr->num_components))); + nir_instr_remove(&intr->instr); +} + +static void +lower_store_output_to_scalar(nir_builder *b, nir_intrinsic_instr *intr) +{ + b->cursor = nir_before_instr(&intr->instr); + + nir_ssa_def *value = nir_ssa_for_src(b, intr->src[0], intr->num_components); + + for (unsigned i = 0; i < intr->num_components; i++) { + if (!(nir_intrinsic_write_mask(intr) & (1 << i))) + continue; + + nir_intrinsic_instr *chan_intr = + nir_intrinsic_instr_create(b->shader, intr->intrinsic); + chan_intr->num_components = 1; + + nir_intrinsic_set_base(chan_intr, nir_intrinsic_base(intr)); + nir_intrinsic_set_write_mask(chan_intr, 0x1); + nir_intrinsic_set_component(chan_intr, nir_intrinsic_component(intr) + i); + + /* value */ + chan_intr->src[0] = nir_src_for_ssa(nir_channel(b, value, i)); + /* offset */ + chan_intr->src[1] = intr->src[1]; + + nir_builder_instr_insert(b, &chan_intr->instr); + } + + nir_instr_remove(&intr->instr); +} + +void +nir_lower_io_to_scalar(nir_shader *shader, nir_variable_mode mask) +{ + nir_foreach_function(function, shader) { + if (function->impl) { + nir_builder b; + nir_builder_init(&b, function->impl); + + nir_foreach_block(block, function->impl) { + nir_foreach_instr_safe(instr, block) { + if (instr->type != nir_instr_type_intrinsic) + continue; + + nir_intrinsic_instr *intr = nir_instr_as_intrinsic(instr); + + if (intr->num_components == 1) + continue; + + switch (intr->intrinsic) { + case nir_intrinsic_load_input: + if (mask & nir_var_shader_in) + lower_load_input_to_scalar(&b, intr); + break; + case nir_intrinsic_store_output: + if (mask & nir_var_shader_out) + lower_store_output_to_scalar(&b, intr); + break; + default: + break; + } + } + } + } + } +} -- 2.30.2