--- /dev/null
+/*
+ * 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.h"
+#include "nir_builder.h"
+#include "nir_deref.h"
+
+struct var_info {
+ bool is_constant;
+ bool found_read;
+};
+
+static nir_ssa_def *
+build_constant_load(nir_builder *b, nir_deref_instr *deref,
+ glsl_type_size_align_func size_align)
+{
+ nir_variable *var = nir_deref_instr_get_variable(deref);
+
+ const unsigned bit_size = glsl_get_bit_size(deref->type);
+ const unsigned num_components = glsl_get_vector_elements(deref->type);
+
+ UNUSED unsigned var_size, var_align;
+ size_align(var->type, &var_size, &var_align);
+ assert(var->data.location % var_align == 0);
+
+ nir_intrinsic_instr *load =
+ nir_intrinsic_instr_create(b->shader, nir_intrinsic_load_constant);
+ load->num_components = num_components;
+ nir_intrinsic_set_base(load, var->data.location);
+ nir_intrinsic_set_range(load, var_size);
+ load->src[0] = nir_src_for_ssa(nir_build_deref_offset(b, deref, size_align));
+ nir_ssa_dest_init(&load->instr, &load->dest,
+ num_components, bit_size, NULL);
+ nir_builder_instr_insert(b, &load->instr);
+
+ return &load->dest.ssa;
+}
+
+static void
+handle_constant_store(nir_builder *b, nir_intrinsic_instr *store,
+ glsl_type_size_align_func size_align)
+{
+ nir_deref_instr *deref = nir_src_as_deref(store->src[0]);
+ assert(!nir_deref_instr_has_indirect(deref));
+
+ nir_variable *var = nir_deref_instr_get_variable(deref);
+
+ const unsigned bit_size = glsl_get_bit_size(deref->type);
+ const unsigned num_components = glsl_get_vector_elements(deref->type);
+
+ char *dst = (char *)b->shader->constant_data +
+ var->data.location +
+ nir_deref_instr_get_const_offset(deref, size_align);
+
+ nir_const_value *val = nir_src_as_const_value(store->src[1]);
+ switch (bit_size) {
+ case 8:
+ for (unsigned i = 0; i < num_components; i++)
+ ((uint8_t *)dst)[i] = val->u8[i];
+ break;
+
+ case 16:
+ for (unsigned i = 0; i < num_components; i++)
+ ((uint16_t *)dst)[i] = val->u16[i];
+ break;
+
+ case 32:
+ for (unsigned i = 0; i < num_components; i++)
+ ((uint32_t *)dst)[i] = val->u32[i];
+ break;
+
+ case 64:
+ for (unsigned i = 0; i < num_components; i++)
+ ((uint64_t *)dst)[i] = val->u64[i];
+ break;
+
+ default:
+ unreachable("Invalid bit size");
+ }
+}
+
+/** Lower large constant variables to shader constant data
+ *
+ * This pass looks for large (type_size(var->type) > threshold) variables
+ * which are statically constant and moves them into shader constant data.
+ * This is especially useful when large tables are baked into the shader
+ * source code because they can be moved into a UBO by the driver to reduce
+ * register pressure and make indirect access cheaper.
+ */
+bool
+nir_opt_large_constants(nir_shader *shader,
+ glsl_type_size_align_func size_align,
+ unsigned threshold)
+{
+ /* Default to a natural alignment if none is provided */
+ if (size_align == NULL)
+ size_align = glsl_get_natural_size_align_bytes;
+
+ /* This only works with a single entrypoint */
+ nir_function_impl *impl = nir_shader_get_entrypoint(shader);
+
+ /* This pass can only be run once */
+ assert(shader->constant_data == NULL && shader->constant_data_size == 0);
+
+ /* The index parameter is unused for local variables so we'll use it for
+ * indexing into our array of variable metadata.
+ */
+ unsigned num_locals = 0;
+ nir_foreach_variable(var, &impl->locals)
+ var->data.index = num_locals++;
+
+ struct var_info *var_infos = malloc(num_locals * sizeof(struct var_info));
+ for (unsigned i = 0; i < num_locals; i++) {
+ var_infos[i] = (struct var_info) {
+ .is_constant = true,
+ .found_read = false,
+ };
+ }
+
+ /* First, walk through the shader and figure out what variables we can
+ * lower to the constant blob.
+ */
+ bool first_block = true;
+ nir_foreach_block(block, impl) {
+ nir_foreach_instr(instr, block) {
+ if (instr->type != nir_instr_type_intrinsic)
+ continue;
+
+ nir_intrinsic_instr *intrin = nir_instr_as_intrinsic(instr);
+
+ bool src_is_const = false;
+ nir_deref_instr *src_deref = NULL, *dst_deref = NULL;
+ switch (intrin->intrinsic) {
+ case nir_intrinsic_store_deref:
+ dst_deref = nir_src_as_deref(intrin->src[0]);
+ src_is_const = nir_src_as_const_value(intrin->src[1]);
+ break;
+
+ case nir_intrinsic_load_deref:
+ src_deref = nir_src_as_deref(intrin->src[0]);
+ break;
+
+ case nir_intrinsic_copy_deref:
+ /* We always assume the src and therefore the dst are not
+ * constants here. Copy and constant propagation passes should
+ * have taken care of this in most cases anyway.
+ */
+ dst_deref = nir_src_as_deref(intrin->src[0]);
+ src_deref = nir_src_as_deref(intrin->src[1]);
+ src_is_const = false;
+ break;
+
+ default:
+ continue;
+ }
+
+ if (dst_deref && dst_deref->mode == nir_var_local) {
+ nir_variable *var = nir_deref_instr_get_variable(dst_deref);
+ assert(var->data.mode == nir_var_local);
+
+ /* We only consider variables constant if they only have constant
+ * stores, all the stores come before any reads, and all stores
+ * come in the first block. We also can't handle indirect stores.
+ */
+ struct var_info *info = &var_infos[var->data.index];
+ if (!src_is_const || info->found_read || !first_block ||
+ nir_deref_instr_has_indirect(dst_deref))
+ info->is_constant = false;
+ }
+
+ if (src_deref && src_deref->mode == nir_var_local) {
+ nir_variable *var = nir_deref_instr_get_variable(src_deref);
+ assert(var->data.mode == nir_var_local);
+
+ var_infos[var->data.index].found_read = true;
+ }
+ }
+ first_block = false;
+ }
+
+ shader->constant_data_size = 0;
+ nir_foreach_variable(var, &impl->locals) {
+ struct var_info *info = &var_infos[var->data.index];
+ if (!info->is_constant)
+ continue;
+
+ unsigned var_size, var_align;
+ size_align(var->type, &var_size, &var_align);
+ if (var_size <= threshold || !info->found_read) {
+ /* Don't bother lowering small stuff or data that's never read */
+ info->is_constant = false;
+ continue;
+ }
+
+ var->data.location = ALIGN_POT(shader->constant_data_size, var_align);
+ shader->constant_data_size = var->data.location + var_size;
+ }
+
+ if (shader->constant_data_size == 0) {
+ free(var_infos);
+ return false;
+ }
+
+ shader->constant_data = rzalloc_size(shader, shader->constant_data_size);
+
+ nir_builder b;
+ nir_builder_init(&b, impl);
+
+ nir_foreach_block(block, impl) {
+ nir_foreach_instr_safe(instr, block) {
+ if (instr->type != nir_instr_type_intrinsic)
+ continue;
+
+ nir_intrinsic_instr *intrin = nir_instr_as_intrinsic(instr);
+
+ switch (intrin->intrinsic) {
+ case nir_intrinsic_load_deref: {
+ nir_deref_instr *deref = nir_src_as_deref(intrin->src[0]);
+ if (deref->mode != nir_var_local)
+ continue;
+
+ nir_variable *var = nir_deref_instr_get_variable(deref);
+ struct var_info *info = &var_infos[var->data.index];
+ if (info->is_constant) {
+ b.cursor = nir_after_instr(&intrin->instr);
+ nir_ssa_def *val = build_constant_load(&b, deref, size_align);
+ nir_ssa_def_rewrite_uses(&intrin->dest.ssa,
+ nir_src_for_ssa(val));
+ nir_instr_remove(&intrin->instr);
+ nir_deref_instr_remove_if_unused(deref);
+ }
+ break;
+ }
+
+ case nir_intrinsic_store_deref: {
+ nir_deref_instr *deref = nir_src_as_deref(intrin->src[0]);
+ if (deref->mode != nir_var_local)
+ continue;
+
+ nir_variable *var = nir_deref_instr_get_variable(deref);
+ struct var_info *info = &var_infos[var->data.index];
+ if (info->is_constant) {
+ b.cursor = nir_after_instr(&intrin->instr);
+ handle_constant_store(&b, intrin, size_align);
+ nir_instr_remove(&intrin->instr);
+ nir_deref_instr_remove_if_unused(deref);
+ }
+ break;
+ }
+
+ case nir_intrinsic_copy_deref: {
+ nir_deref_instr *deref = nir_src_as_deref(intrin->src[1]);
+ if (deref->mode != nir_var_local)
+ continue;
+
+ nir_variable *var = nir_deref_instr_get_variable(deref);
+ struct var_info *info = &var_infos[var->data.index];
+ if (info->is_constant) {
+ b.cursor = nir_after_instr(&intrin->instr);
+ nir_ssa_def *val = build_constant_load(&b, deref, size_align);
+ nir_store_deref(&b, nir_src_as_deref(intrin->src[0]), val, ~0);
+ nir_instr_remove(&intrin->instr);
+ nir_deref_instr_remove_if_unused(deref);
+ }
+ break;
+ }
+
+ default:
+ continue;
+ }
+ }
+ }
+
+ /* Clean up the now unused variables */
+ nir_foreach_variable_safe(var, &impl->locals) {
+ if (var_infos[var->data.index].is_constant)
+ exec_node_remove(&var->node);
+ }
+
+ free(var_infos);
+
+ nir_metadata_preserve(impl, nir_metadata_block_index |
+ nir_metadata_dominance);
+ return true;
+}
projects / mesa.git / commitdiff