From c1dfdcb93a8991788032d4906c5bf1a5b48cdc48 Mon Sep 17 00:00:00 2001 From: Eric Anholt Date: Thu, 26 Aug 2010 12:02:26 -0700 Subject: [PATCH] i965: Add new pass to split vectors into scalar variables Combined with the previous pass, this lets other optimization passes do their work thanks to ir_tree_grafting. Still have regression in instruction count with INTEL_NEW_FS, but register count is even better. --- src/mesa/drivers/dri/i965/Makefile | 3 +- src/mesa/drivers/dri/i965/brw_fs.cpp | 2 + .../dri/i965/brw_fs_vector_splitting.cpp | 388 ++++++++++++++++++ src/mesa/drivers/dri/i965/brw_wm.h | 1 + 4 files changed, 393 insertions(+), 1 deletion(-) create mode 100644 src/mesa/drivers/dri/i965/brw_fs_vector_splitting.cpp diff --git a/src/mesa/drivers/dri/i965/Makefile b/src/mesa/drivers/dri/i965/Makefile index 39acae9e434..bea48e13138 100644 --- a/src/mesa/drivers/dri/i965/Makefile +++ b/src/mesa/drivers/dri/i965/Makefile @@ -106,7 +106,8 @@ C_SOURCES = \ CXX_SOURCES = \ brw_fs.cpp \ - brw_fs_channel_expressions.cpp + brw_fs_channel_expressions.cpp \ + brw_fs_vector_splitting.cpp ASM_SOURCES = diff --git a/src/mesa/drivers/dri/i965/brw_fs.cpp b/src/mesa/drivers/dri/i965/brw_fs.cpp index d16e75a2ca9..9a6ee7a0100 100644 --- a/src/mesa/drivers/dri/i965/brw_fs.cpp +++ b/src/mesa/drivers/dri/i965/brw_fs.cpp @@ -37,6 +37,7 @@ extern "C" { #include "talloc.h" } #include "../glsl/ir_optimization.h" +#include "../glsl/ir_print_visitor.h" struct gl_shader * brw_new_shader(GLcontext *ctx, GLuint name, GLuint type) @@ -87,6 +88,7 @@ brw_link_shader(GLcontext *ctx, struct gl_shader_program *prog) if (using_new_fs && shader->Type == GL_FRAGMENT_SHADER) { do_mat_op_to_vec(shader->ir); brw_do_channel_expressions(shader->ir); + brw_do_vector_splitting(shader->ir); } } diff --git a/src/mesa/drivers/dri/i965/brw_fs_vector_splitting.cpp b/src/mesa/drivers/dri/i965/brw_fs_vector_splitting.cpp new file mode 100644 index 00000000000..d4da86b3b06 --- /dev/null +++ b/src/mesa/drivers/dri/i965/brw_fs_vector_splitting.cpp @@ -0,0 +1,388 @@ +/* + * Copyright © 2010 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. + */ + +/** + * \file brw_wm_vector_splitting.cpp + * + * If a vector is only ever referenced by its components, then + * split those components out to individual variables so they can be + * handled normally by other optimization passes. + * + * This skips vectors in uniforms and varyings, which need to be + * accessible as vectors for their access by the GL. Also, vector + * results of non-variable-derefs in assignments aren't handled + * because to do so we would have to store the vector result to a + * temporary in order to unload each channel, and to do so would just + * loop us back to where we started. For the 965, this is exactly the + * behavior we want for the results of texture lookups, but probably not for + */ + +extern "C" { +#include "main/core.h" +#include "intel_context.h" +} +#include "../glsl/ir.h" +#include "../glsl/ir_visitor.h" +#include "../glsl/ir_print_visitor.h" +#include "../glsl/ir_rvalue_visitor.h" +#include "../glsl/glsl_types.h" + +static bool debug = false; + +class variable_entry : public exec_node +{ +public: + variable_entry(ir_variable *var) + { + this->var = var; + this->whole_vector_access = 0; + this->declaration = false; + this->mem_ctx = NULL; + } + + ir_variable *var; /* The key: the variable's pointer. */ + + /** Number of times the variable is referenced, including assignments. */ + unsigned whole_vector_access; + + bool declaration; /* If the variable had a decl in the instruction stream */ + + ir_variable *components[4]; + + /** talloc_parent(this->var) -- the shader's talloc context. */ + void *mem_ctx; +}; + +class ir_vector_reference_visitor : public ir_hierarchical_visitor { +public: + ir_vector_reference_visitor(void) + { + this->mem_ctx = talloc_new(NULL); + this->variable_list.make_empty(); + } + + ~ir_vector_reference_visitor(void) + { + talloc_free(mem_ctx); + } + + virtual ir_visitor_status visit(ir_variable *); + virtual ir_visitor_status visit(ir_dereference_variable *); + virtual ir_visitor_status visit_enter(ir_swizzle *); + virtual ir_visitor_status visit_enter(ir_assignment *); + virtual ir_visitor_status visit_enter(ir_function_signature *); + + variable_entry *get_variable_entry(ir_variable *var); + + /* List of variable_entry */ + exec_list variable_list; + + void *mem_ctx; +}; + +variable_entry * +ir_vector_reference_visitor::get_variable_entry(ir_variable *var) +{ + assert(var); + + if (!var->type->is_vector()) + return NULL; + + switch (var->mode) { + case ir_var_uniform: + case ir_var_in: + case ir_var_out: + case ir_var_inout: + /* Can't split varyings or uniforms. Function in/outs won't get split + * either, so don't care about the ambiguity. + */ + return NULL; + case ir_var_auto: + case ir_var_temporary: + break; + } + + foreach_iter(exec_list_iterator, iter, this->variable_list) { + variable_entry *entry = (variable_entry *)iter.get(); + if (entry->var == var) + return entry; + } + + variable_entry *entry = new(mem_ctx) variable_entry(var); + this->variable_list.push_tail(entry); + return entry; +} + + +ir_visitor_status +ir_vector_reference_visitor::visit(ir_variable *ir) +{ + variable_entry *entry = this->get_variable_entry(ir); + + if (entry) + entry->declaration = true; + + return visit_continue; +} + +ir_visitor_status +ir_vector_reference_visitor::visit(ir_dereference_variable *ir) +{ + ir_variable *const var = ir->var; + variable_entry *entry = this->get_variable_entry(var); + + if (entry) + entry->whole_vector_access++; + + return visit_continue; +} + +ir_visitor_status +ir_vector_reference_visitor::visit_enter(ir_swizzle *ir) +{ + /* Don't descend into a vector ir_dereference_variable below. */ + if (ir->val->as_dereference_variable() && ir->type->is_scalar()) + return visit_continue_with_parent; + + return visit_continue; +} + +ir_visitor_status +ir_vector_reference_visitor::visit_enter(ir_assignment *ir) +{ + if (ir->lhs->as_dereference_variable() && + ir->rhs->as_dereference_variable() && + !ir->condition) { + /* We'll split copies of a vector to copies of channels, so don't + * descend to the ir_dereference_variables. + */ + return visit_continue_with_parent; + } + if (ir->lhs->as_dereference_variable() && + is_power_of_two(ir->write_mask) && + !ir->condition) { + /* If we're writing just a channel, then channel-splitting the LHS is OK. + */ + ir->rhs->accept(this); + return visit_continue_with_parent; + } + return visit_continue; +} + +ir_visitor_status +ir_vector_reference_visitor::visit_enter(ir_function_signature *ir) +{ + /* We don't want to descend into the function parameters and + * split them, so just accept the body here. + */ + visit_list_elements(this, &ir->body); + return visit_continue_with_parent; +} + +class ir_vector_splitting_visitor : public ir_rvalue_visitor { +public: + ir_vector_splitting_visitor(exec_list *vars) + { + this->variable_list = vars; + } + + virtual ir_visitor_status visit_leave(ir_assignment *); + + void handle_rvalue(ir_rvalue **rvalue); + struct variable_entry *get_splitting_entry(ir_variable *var); + + exec_list *variable_list; + void *mem_ctx; +}; + +struct variable_entry * +ir_vector_splitting_visitor::get_splitting_entry(ir_variable *var) +{ + assert(var); + + if (!var->type->is_vector()) + return NULL; + + foreach_iter(exec_list_iterator, iter, *this->variable_list) { + variable_entry *entry = (variable_entry *)iter.get(); + if (entry->var == var) { + return entry; + } + } + + return NULL; +} + +void +ir_vector_splitting_visitor::handle_rvalue(ir_rvalue **rvalue) +{ + if (!*rvalue) + return; + + ir_swizzle *swiz = (*rvalue)->as_swizzle(); + if (!swiz || !swiz->type->is_scalar()) + return; + + ir_dereference_variable *deref_var = swiz->val->as_dereference_variable(); + if (!deref_var) + return; + + variable_entry *entry = get_splitting_entry(deref_var->var); + if (!entry) + return; + + ir_variable *var = entry->components[swiz->mask.x]; + *rvalue = new(entry->mem_ctx) ir_dereference_variable(var); +} + +ir_visitor_status +ir_vector_splitting_visitor::visit_leave(ir_assignment *ir) +{ + ir_dereference_variable *lhs_deref = ir->lhs->as_dereference_variable(); + ir_dereference_variable *rhs_deref = ir->rhs->as_dereference_variable(); + variable_entry *lhs = lhs_deref ? get_splitting_entry(lhs_deref->var) : NULL; + variable_entry *rhs = rhs_deref ? get_splitting_entry(rhs_deref->var) : NULL; + + if (lhs_deref && rhs_deref && (lhs || rhs) && !ir->condition) { + /* Straight assignment of vector variables. */ + for (unsigned int i = 0; i < ir->rhs->type->vector_elements; i++) { + ir_dereference *new_lhs; + ir_rvalue *new_rhs; + void *mem_ctx = lhs ? lhs->mem_ctx : rhs->mem_ctx; + unsigned int writemask; + + if (lhs) { + new_lhs = new(mem_ctx) ir_dereference_variable(lhs->components[i]); + writemask = (ir->write_mask >> i) & 1; + } else { + new_lhs = ir->lhs->clone(mem_ctx, NULL); + writemask = ir->write_mask & (1 << i); + } + + if (rhs) { + new_rhs = new(mem_ctx) ir_dereference_variable(rhs->components[i]); + } else { + new_rhs = new(mem_ctx) ir_swizzle(ir->rhs->clone(mem_ctx, NULL), + i, i, i, i, 1); + } + + ir->insert_before(new(mem_ctx) ir_assignment(new_lhs, + new_rhs, + NULL, writemask)); + } + ir->remove(); + } else if (lhs) { + int elem = -1; + + switch (ir->write_mask) { + case (1 << 0): + elem = 0; + break; + case (1 << 1): + elem = 1; + break; + case (1 << 2): + elem = 2; + break; + case (1 << 3): + elem = 3; + break; + default: + ir->print(); + assert(!"not reached: non-channelwise dereference of LHS."); + } + + ir->lhs = new(mem_ctx) ir_dereference_variable(lhs->components[elem]); + ir->write_mask = (1 << 0); + + handle_rvalue(&ir->rhs); + ir->rhs = new(mem_ctx) ir_swizzle(ir->rhs, + elem, elem, elem, elem, 1); + } else { + handle_rvalue(&ir->rhs); + } + + handle_rvalue(&ir->condition); + + return visit_continue; +} + +extern "C" { +bool +brw_do_vector_splitting(exec_list *instructions) +{ + ir_vector_reference_visitor refs; + + visit_list_elements(&refs, instructions); + + /* Trim out variables we can't split. */ + foreach_iter(exec_list_iterator, iter, refs.variable_list) { + variable_entry *entry = (variable_entry *)iter.get(); + + if (debug) { + printf("vector %s@%p: decl %d, whole_access %d\n", + entry->var->name, (void *) entry->var, entry->declaration, + entry->whole_vector_access); + } + + if (!entry->declaration || entry->whole_vector_access) { + entry->remove(); + } + } + + if (refs.variable_list.is_empty()) + return false; + + void *mem_ctx = talloc_new(NULL); + + /* Replace the decls of the vectors to be split with their split + * components. + */ + foreach_iter(exec_list_iterator, iter, refs.variable_list) { + variable_entry *entry = (variable_entry *)iter.get(); + const struct glsl_type *type; + type = glsl_type::get_instance(entry->var->type->base_type, 1, 1); + + entry->mem_ctx = talloc_parent(entry->var); + + for (unsigned int i = 0; i < entry->var->type->vector_elements; i++) { + const char *name = talloc_asprintf(mem_ctx, "%s_%c", + entry->var->name, + "xyzw"[i]); + + entry->components[i] = new(entry->mem_ctx) ir_variable(type, name, + ir_var_temporary); + entry->var->insert_before(entry->components[i]); + } + + entry->var->remove(); + } + + ir_vector_splitting_visitor split(&refs.variable_list); + visit_list_elements(&split, instructions); + + talloc_free(mem_ctx); + + return true; +} +} diff --git a/src/mesa/drivers/dri/i965/brw_wm.h b/src/mesa/drivers/dri/i965/brw_wm.h index 438da1af622..6a761e723b4 100644 --- a/src/mesa/drivers/dri/i965/brw_wm.h +++ b/src/mesa/drivers/dri/i965/brw_wm.h @@ -466,5 +466,6 @@ struct gl_shader *brw_new_shader(GLcontext *ctx, GLuint name, GLuint type); struct gl_shader_program *brw_new_shader_program(GLcontext *ctx, GLuint name); GLboolean brw_do_channel_expressions(struct exec_list *instructions); +GLboolean brw_do_vector_splitting(struct exec_list *instructions); #endif -- 2.30.2