From 9dd0cfafc9ec4b4efb1e2df0329afc7a5a534231 Mon Sep 17 00:00:00 2001 From: Eduardo Lima Mitev Date: Sun, 13 Jan 2019 20:10:34 +0100 Subject: [PATCH] ir3/nir: Add a new pass 'ir3_nir_lower_io_offsets' This NIR->NIR pass implements offset computations that are currently done on the IR3 backend compiler, to give NIR a better chance of optimizing them. For now, it supports lowering the dword-offset computation for SSBO instructions. It will take an SSBO intrinsic and replace it with the new ir3-specific version that adds an extra source. That source will hold the SSA value resulting from inserting a division by 4 (an SHR op) of the original byte-offset source already provided by NIR in one of the intrinsic sources. Note that on a6xx the original byte-offset is not needed, so we could potentially replace that source instead of adding a new one. But to keep things simple and consistent we always add the new source and a6xx will just ignore the original one. Reviewed-by: Rob Clark --- src/freedreno/Makefile.sources | 1 + src/freedreno/ir3/ir3_nir.h | 1 + src/freedreno/ir3/ir3_nir_lower_io_offsets.c | 214 +++++++++++++++++++ src/freedreno/ir3/meson.build | 1 + 4 files changed, 217 insertions(+) create mode 100644 src/freedreno/ir3/ir3_nir_lower_io_offsets.c diff --git a/src/freedreno/Makefile.sources b/src/freedreno/Makefile.sources index d4c2103708d..91fb74a8564 100644 --- a/src/freedreno/Makefile.sources +++ b/src/freedreno/Makefile.sources @@ -35,6 +35,7 @@ ir3_SOURCES := \ ir3/ir3_legalize.c \ ir3/ir3_nir.c \ ir3/ir3_nir.h \ + ir3/ir3_nir_lower_io_offsets.c \ ir3/ir3_nir_lower_tg4_to_tex.c \ ir3/ir3_print.c \ ir3/ir3_ra.c \ diff --git a/src/freedreno/ir3/ir3_nir.h b/src/freedreno/ir3/ir3_nir.h index 74201d34160..7983b74af2c 100644 --- a/src/freedreno/ir3/ir3_nir.h +++ b/src/freedreno/ir3/ir3_nir.h @@ -36,6 +36,7 @@ void ir3_nir_scan_driver_consts(nir_shader *shader, struct ir3_driver_const_layo bool ir3_nir_apply_trig_workarounds(nir_shader *shader); bool ir3_nir_lower_tg4_to_tex(nir_shader *shader); +bool ir3_nir_lower_io_offsets(nir_shader *shader); const nir_shader_compiler_options * ir3_get_compiler_options(struct ir3_compiler *compiler); bool ir3_key_lowers_nir(const struct ir3_shader_key *key); diff --git a/src/freedreno/ir3/ir3_nir_lower_io_offsets.c b/src/freedreno/ir3/ir3_nir_lower_io_offsets.c new file mode 100644 index 00000000000..264f1064545 --- /dev/null +++ b/src/freedreno/ir3/ir3_nir_lower_io_offsets.c @@ -0,0 +1,214 @@ +/* + * Copyright © 2018-2019 Igalia S.L. + * + * 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 "ir3_nir.h" +#include "compiler/nir/nir_builder.h" + +/** + * This pass moves to NIR certain offset computations for different I/O + * ops that are currently implemented on the IR3 backend compiler, to + * give NIR a chance to optimize them: + * + * - Dword-offset for SSBO load, store and atomics: A new, similar intrinsic + * is emitted that replaces the original one, adding a new source that + * holds the result of the original byte-offset source divided by 4. + */ + + +/* Returns the ir3-specific intrinsic opcode corresponding to an SSBO + * instruction that is handled by this pass. It also conveniently returns + * the offset source index in @offset_src_idx. + * + * If @intrinsic is not SSBO, or it is not handled by the pass, -1 is + * returned. + */ +static int +get_ir3_intrinsic_for_ssbo_intrinsic(unsigned intrinsic, + uint8_t *offset_src_idx) +{ + debug_assert(offset_src_idx); + + *offset_src_idx = 1; + + switch (intrinsic) { + case nir_intrinsic_store_ssbo: + *offset_src_idx = 2; + return nir_intrinsic_store_ssbo_ir3; + case nir_intrinsic_load_ssbo: + return nir_intrinsic_load_ssbo_ir3; + case nir_intrinsic_ssbo_atomic_add: + return nir_intrinsic_ssbo_atomic_add_ir3; + case nir_intrinsic_ssbo_atomic_imin: + return nir_intrinsic_ssbo_atomic_imin_ir3; + case nir_intrinsic_ssbo_atomic_umin: + return nir_intrinsic_ssbo_atomic_umin_ir3; + case nir_intrinsic_ssbo_atomic_imax: + return nir_intrinsic_ssbo_atomic_imax_ir3; + case nir_intrinsic_ssbo_atomic_umax: + return nir_intrinsic_ssbo_atomic_umax_ir3; + case nir_intrinsic_ssbo_atomic_and: + return nir_intrinsic_ssbo_atomic_and_ir3; + case nir_intrinsic_ssbo_atomic_or: + return nir_intrinsic_ssbo_atomic_or_ir3; + case nir_intrinsic_ssbo_atomic_xor: + return nir_intrinsic_ssbo_atomic_xor_ir3; + case nir_intrinsic_ssbo_atomic_exchange: + return nir_intrinsic_ssbo_atomic_exchange_ir3; + case nir_intrinsic_ssbo_atomic_comp_swap: + return nir_intrinsic_ssbo_atomic_comp_swap_ir3; + default: + break; + } + + return -1; +} + +static bool +lower_offset_for_ssbo(nir_intrinsic_instr *intrinsic, nir_builder *b, + unsigned ir3_ssbo_opcode, uint8_t offset_src_idx) +{ + unsigned num_srcs = nir_intrinsic_infos[intrinsic->intrinsic].num_srcs; + + bool has_dest = nir_intrinsic_infos[intrinsic->intrinsic].has_dest; + nir_ssa_def *new_dest = NULL; + + /* Here we create a new intrinsic and copy over all contents from the old one. */ + + nir_intrinsic_instr *new_intrinsic; + nir_src *target_src; + + /* 'offset_src_idx' holds the index of the source that represent the offset. */ + new_intrinsic = + nir_intrinsic_instr_create(b->shader, ir3_ssbo_opcode); + + debug_assert(intrinsic->src[offset_src_idx].is_ssa); + nir_ssa_def *offset = intrinsic->src[offset_src_idx].ssa; + + /* The new source that will hold the dword-offset is always the last + * one for every intrinsic. + */ + target_src = &new_intrinsic->src[num_srcs]; + *target_src = nir_src_for_ssa(offset); + + if (has_dest) { + debug_assert(intrinsic->dest.is_ssa); + nir_ssa_def *dest = &intrinsic->dest.ssa; + nir_ssa_dest_init(&new_intrinsic->instr, &new_intrinsic->dest, + dest->num_components, dest->bit_size, NULL); + new_dest = &new_intrinsic->dest.ssa; + } + + for (unsigned i = 0; i < num_srcs; i++) + new_intrinsic->src[i] = nir_src_for_ssa(intrinsic->src[i].ssa); + + for (unsigned i = 0; i < NIR_INTRINSIC_MAX_CONST_INDEX; i++) + new_intrinsic->const_index[i] = intrinsic->const_index[i]; + + new_intrinsic->num_components = intrinsic->num_components; + + b->cursor = nir_before_instr(&intrinsic->instr); + nir_ssa_def *offset_div_4 = nir_ushr(b, offset, nir_imm_int(b, 2)); + debug_assert(offset_div_4); + + /* Insert the new intrinsic right before the old one. */ + b->cursor = nir_before_instr(&intrinsic->instr); + nir_builder_instr_insert(b, &new_intrinsic->instr); + + /* Replace the last source of the new intrinsic by the result of + * the offset divided by 4. + */ + nir_instr_rewrite_src(&new_intrinsic->instr, + target_src, + nir_src_for_ssa(offset_div_4)); + + if (has_dest) { + /* Replace the uses of the original destination by that + * of the new intrinsic. + */ + nir_ssa_def_rewrite_uses(&intrinsic->dest.ssa, + nir_src_for_ssa(new_dest)); + } + + /* Finally remove the original intrinsic. */ + nir_instr_remove(&intrinsic->instr); + + return true; +} + +static bool +lower_io_offsets_block(nir_block *block, nir_builder *b, void *mem_ctx) +{ + bool progress = false; + + nir_foreach_instr_safe(instr, block) { + if (instr->type != nir_instr_type_intrinsic) + continue; + + nir_intrinsic_instr *intr = nir_instr_as_intrinsic(instr); + + /* SSBO */ + int ir3_intrinsic; + uint8_t offset_src_idx; + ir3_intrinsic = get_ir3_intrinsic_for_ssbo_intrinsic(intr->intrinsic, + &offset_src_idx); + if (ir3_intrinsic != -1) { + progress |= lower_offset_for_ssbo(intr, b, (unsigned) ir3_intrinsic, + offset_src_idx); + } + } + + return progress; +} + +static bool +lower_io_offsets_func(nir_function_impl *impl) +{ + void *mem_ctx = ralloc_parent(impl); + nir_builder b; + nir_builder_init(&b, impl); + + bool progress = false; + nir_foreach_block_safe(block, impl) { + progress |= lower_io_offsets_block(block, &b, mem_ctx); + } + + if (progress) { + nir_metadata_preserve(impl, nir_metadata_block_index | + nir_metadata_dominance); + } + + return progress; +} + +bool +ir3_nir_lower_io_offsets(nir_shader *shader) +{ + bool progress = false; + + nir_foreach_function(function, shader) { + if (function->impl) + progress |= lower_io_offsets_func(function->impl); + } + + return progress; +} diff --git a/src/freedreno/ir3/meson.build b/src/freedreno/ir3/meson.build index 5f87ca6185b..d210211cc97 100644 --- a/src/freedreno/ir3/meson.build +++ b/src/freedreno/ir3/meson.build @@ -50,6 +50,7 @@ libfreedreno_ir3_files = files( 'ir3_legalize.c', 'ir3_nir.c', 'ir3_nir.h', + 'ir3_nir_lower_io_offsets.c', 'ir3_nir_lower_tg4_to_tex.c', 'ir3_print.c', 'ir3_ra.c', -- 2.30.2