From: Jason Ekstrand Date: Tue, 2 Dec 2014 04:29:35 +0000 (-0800) Subject: nir: Add a pass to lower local variables to registers X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=aff431293b441368acd907104c8acd1b117bfaf8;p=mesa.git nir: Add a pass to lower local variables to registers Reviewed-by: Connor Abbott --- diff --git a/src/glsl/Makefile.sources b/src/glsl/Makefile.sources index 1d3b0499aaa..6230f49b260 100644 --- a/src/glsl/Makefile.sources +++ b/src/glsl/Makefile.sources @@ -22,6 +22,7 @@ NIR_FILES = \ $(GLSL_SRCDIR)/nir/nir_intrinsics.h \ $(GLSL_SRCDIR)/nir/nir_live_variables.c \ $(GLSL_SRCDIR)/nir/nir_lower_atomics.c \ + $(GLSL_SRCDIR)/nir/nir_lower_locals_to_regs.c \ $(GLSL_SRCDIR)/nir/nir_lower_samplers.cpp \ $(GLSL_SRCDIR)/nir/nir_lower_system_values.c \ $(GLSL_SRCDIR)/nir/nir_lower_variables.c \ diff --git a/src/glsl/nir/nir.h b/src/glsl/nir/nir.h index 9d207bd4255..884cc040ddb 100644 --- a/src/glsl/nir/nir.h +++ b/src/glsl/nir/nir.h @@ -1358,6 +1358,8 @@ void nir_dump_cfg(nir_shader *shader, FILE *fp); void nir_split_var_copies(nir_shader *shader); +void nir_lower_locals_to_regs(nir_shader *shader); + void nir_lower_variables(nir_shader *shader); void nir_lower_variables_scalar(nir_shader *shader, bool lower_globals, diff --git a/src/glsl/nir/nir_lower_locals_to_regs.c b/src/glsl/nir/nir_lower_locals_to_regs.c new file mode 100644 index 00000000000..715c634bcd9 --- /dev/null +++ b/src/glsl/nir/nir_lower_locals_to_regs.c @@ -0,0 +1,313 @@ +/* + * Copyright © 2014 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. + * + * Authors: + * Jason Ekstrand (jason@jlekstrand.net) + * + */ + +#include "nir.h" + +struct locals_to_regs_state { + void *mem_ctx; + nir_function_impl *impl; + + /* A hash table mapping derefs to registers */ + struct hash_table *regs_table; +}; + +/* The following two functions implement a hash and equality check for + * variable dreferences. When the hash or equality function encounters an + * array, it ignores the offset and whether it is direct or indirect + * entirely. + */ +static uint32_t +hash_deref(const void *void_deref) +{ + const nir_deref *deref = void_deref; + + uint32_t hash; + if (deref->child) { + hash = hash_deref(deref->child); + } else { + hash = 2166136261ul; + } + + switch (deref->deref_type) { + case nir_deref_type_var: + hash ^= _mesa_hash_pointer(nir_deref_as_var(deref)->var); + break; + case nir_deref_type_array: { + hash ^= 268435183; + break; + } + case nir_deref_type_struct: + hash ^= nir_deref_as_struct(deref)->index; + break; + } + + return hash * 0x01000193; +} + +static bool +derefs_equal(const void *void_a, const void *void_b) +{ + const nir_deref *a = void_a; + const nir_deref *b = void_b; + + if (a->deref_type != b->deref_type) + return false; + + switch (a->deref_type) { + case nir_deref_type_var: + if (nir_deref_as_var(a)->var != nir_deref_as_var(b)->var) + return false; + break; + case nir_deref_type_array: + /* Do nothing. All array derefs are the same */ + break; + case nir_deref_type_struct: + if (nir_deref_as_struct(a)->index != nir_deref_as_struct(b)->index) + return false; + break; + default: + unreachable("Invalid dreference type"); + } + + assert((a->child == NULL) == (b->child == NULL)); + if (a->child) + return derefs_equal(a->child, b->child); + else + return true; +} + +static nir_register * +get_reg_for_deref(nir_deref_var *deref, struct locals_to_regs_state *state) +{ + uint32_t hash = hash_deref(deref); + + struct hash_entry *entry = + _mesa_hash_table_search_pre_hashed(state->regs_table, hash, deref); + if (entry) + return entry->data; + + unsigned array_size = 1; + nir_deref *tail = &deref->deref; + while (tail->child) { + if (tail->child->deref_type == nir_deref_type_array) { + /* Multiply by the parent's type. */ + if (glsl_type_is_matrix(tail->type)) { + array_size *= glsl_get_matrix_columns(tail->type); + } else { + assert(glsl_get_length(tail->type) > 0); + array_size *= glsl_get_length(tail->type); + } + } + tail = tail->child; + } + + assert(glsl_type_is_vector(tail->type) || glsl_type_is_scalar(tail->type)); + + nir_register *reg = nir_local_reg_create(state->impl); + reg->num_components = glsl_get_vector_elements(tail->type); + reg->num_array_elems = array_size > 1 ? array_size : 0; + + _mesa_hash_table_insert_with_hash(state->regs_table, hash, deref, reg); + + return reg; +} + +static nir_src +get_deref_reg_src(nir_deref_var *deref, nir_instr *instr, + struct locals_to_regs_state *state) +{ + nir_src src; + + src.is_ssa = false; + src.reg.reg = get_reg_for_deref(deref, state); + src.reg.base_offset = 0; + src.reg.indirect = NULL; + + nir_deref *tail = &deref->deref; + while (tail->child != NULL) { + const struct glsl_type *parent_type = tail->type; + tail = tail->child; + + if (tail->deref_type != nir_deref_type_array) + continue; + + nir_deref_array *deref_array = nir_deref_as_array(tail); + + src.reg.base_offset *= glsl_get_length(parent_type); + src.reg.base_offset += deref_array->base_offset; + + if (src.reg.indirect) { + nir_load_const_instr *load_const = + nir_load_const_instr_create(state->mem_ctx); + load_const->num_components = 1; + load_const->value.u[0] = glsl_get_length(parent_type); + load_const->dest.is_ssa = true; + nir_ssa_def_init(&load_const->instr, &load_const->dest.ssa, 1, NULL); + nir_instr_insert_before(instr, &load_const->instr); + + nir_alu_instr *mul = nir_alu_instr_create(state->mem_ctx, nir_op_imul); + mul->src[0].src = *src.reg.indirect; + mul->src[1].src.is_ssa = true; + mul->src[1].src.ssa = &load_const->dest.ssa; + mul->dest.write_mask = 1; + mul->dest.dest.is_ssa = true; + nir_ssa_def_init(&mul->instr, &mul->dest.dest.ssa, 1, NULL); + nir_instr_insert_before(instr, &mul->instr); + + src.reg.indirect->is_ssa = true; + src.reg.indirect->ssa = &mul->dest.dest.ssa; + } + + if (deref_array->deref_array_type == nir_deref_array_type_indirect) { + if (src.reg.indirect == NULL) { + src.reg.indirect = ralloc(state->mem_ctx, nir_src); + *src.reg.indirect = nir_src_copy(deref_array->indirect, + state->mem_ctx); + } else { + nir_alu_instr *add = nir_alu_instr_create(state->mem_ctx, + nir_op_iadd); + add->src[0].src = *src.reg.indirect; + add->src[1].src = nir_src_copy(deref_array->indirect, + state->mem_ctx); + add->dest.write_mask = 1; + add->dest.dest.is_ssa = true; + nir_ssa_def_init(&add->instr, &add->dest.dest.ssa, 1, NULL); + nir_instr_insert_before(instr, &add->instr); + + src.reg.indirect->is_ssa = true; + src.reg.indirect->ssa = &add->dest.dest.ssa; + } + } + } + + return src; +} + +static bool +lower_locals_to_regs_block(nir_block *block, void *void_state) +{ + struct locals_to_regs_state *state = void_state; + + nir_foreach_instr_safe(block, instr) { + if (instr->type != nir_instr_type_intrinsic) + continue; + + nir_intrinsic_instr *intrin = nir_instr_as_intrinsic(instr); + + switch (intrin->intrinsic) { + case nir_intrinsic_load_var_vec1: + case nir_intrinsic_load_var_vec2: + case nir_intrinsic_load_var_vec3: + case nir_intrinsic_load_var_vec4: { + if (intrin->variables[0]->var->data.mode != nir_var_local) + continue; + + nir_alu_instr *mov = nir_alu_instr_create(state->mem_ctx, nir_op_imov); + mov->src[0].src = get_deref_reg_src(intrin->variables[0], + &intrin->instr, state); + unsigned num_components = mov->src[0].src.reg.reg->num_components; + mov->dest.write_mask = (1 << num_components) - 1; + if (intrin->dest.is_ssa) { + mov->dest.dest.is_ssa = true; + nir_ssa_def_init(&mov->instr, &mov->dest.dest.ssa, + num_components, NULL); + + nir_src new_src = { + .is_ssa = true, + .ssa = &mov->dest.dest.ssa, + }; + + nir_ssa_def_rewrite_uses(&intrin->dest.ssa, new_src, + state->mem_ctx); + } else { + mov->dest.dest = nir_dest_copy(intrin->dest, state->mem_ctx); + } + nir_instr_insert_before(&intrin->instr, &mov->instr); + + nir_instr_remove(&intrin->instr); + break; + } + + case nir_intrinsic_store_var_vec1: + case nir_intrinsic_store_var_vec2: + case nir_intrinsic_store_var_vec3: + case nir_intrinsic_store_var_vec4: { + if (intrin->variables[0]->var->data.mode != nir_var_local) + continue; + + nir_src reg_src = get_deref_reg_src(intrin->variables[0], + &intrin->instr, state); + unsigned num_components = reg_src.reg.reg->num_components; + + nir_alu_instr *mov = nir_alu_instr_create(state->mem_ctx, nir_op_imov); + mov->src[0].src = nir_src_copy(intrin->src[0], state->mem_ctx); + mov->dest.write_mask = (1 << num_components) - 1; + mov->dest.dest.is_ssa = false; + mov->dest.dest.reg.reg = reg_src.reg.reg; + mov->dest.dest.reg.base_offset = reg_src.reg.base_offset; + mov->dest.dest.reg.indirect = reg_src.reg.indirect; + + nir_instr_insert_before(&intrin->instr, &mov->instr); + + nir_instr_remove(&intrin->instr); + break; + } + + case nir_intrinsic_copy_var: + unreachable("There should be no copies whatsoever at this point"); + break; + + default: + continue; + } + } + + return true; +} + +static void +nir_lower_locals_to_regs_impl(nir_function_impl *impl) +{ + struct locals_to_regs_state state; + + state.mem_ctx = ralloc_parent(impl); + state.impl = impl; + state.regs_table = _mesa_hash_table_create(NULL, hash_deref, derefs_equal); + + nir_foreach_block(impl, lower_locals_to_regs_block, &state); + + _mesa_hash_table_destroy(state.regs_table, NULL); +} + +void +nir_lower_locals_to_regs(nir_shader *shader) +{ + nir_foreach_overload(shader, overload) { + if (overload->impl) + nir_lower_locals_to_regs_impl(overload->impl); + } +}