| /* |
| * 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 opt_copy_propagation_elements.cpp |
| * |
| * Replaces usage of recently-copied components of variables with the |
| * previous copy of the variable. |
| * |
| * This pass can be compared with opt_copy_propagation, which operands |
| * on arbitrary whole-variable copies. However, in order to handle |
| * the copy propagation of swizzled variables or writemasked writes, |
| * we want to track things on a channel-wise basis. I found that |
| * trying to mix the swizzled/writemasked support here with the |
| * whole-variable stuff in opt_copy_propagation.cpp just made a mess, |
| * so this is separate despite the ACP handling being somewhat |
| * similar. |
| * |
| * This should reduce the number of MOV instructions in the generated |
| * programs unless copy propagation is also done on the LIR, and may |
| * help anyway by triggering other optimizations that live in the HIR. |
| */ |
| |
| #include "ir.h" |
| #include "ir_rvalue_visitor.h" |
| #include "ir_basic_block.h" |
| #include "ir_optimization.h" |
| #include "glsl_types.h" |
| |
| static bool debug = false; |
| |
| namespace { |
| |
| class acp_entry : public exec_node |
| { |
| public: |
| acp_entry(ir_variable *lhs, ir_variable *rhs, int write_mask, int swizzle[4]) |
| { |
| this->lhs = lhs; |
| this->rhs = rhs; |
| this->write_mask = write_mask; |
| memcpy(this->swizzle, swizzle, sizeof(this->swizzle)); |
| } |
| |
| acp_entry(acp_entry *a) |
| { |
| this->lhs = a->lhs; |
| this->rhs = a->rhs; |
| this->write_mask = a->write_mask; |
| memcpy(this->swizzle, a->swizzle, sizeof(this->swizzle)); |
| } |
| |
| ir_variable *lhs; |
| ir_variable *rhs; |
| unsigned int write_mask; |
| int swizzle[4]; |
| }; |
| |
| |
| class kill_entry : public exec_node |
| { |
| public: |
| kill_entry(ir_variable *var, int write_mask) |
| { |
| this->var = var; |
| this->write_mask = write_mask; |
| } |
| |
| ir_variable *var; |
| unsigned int write_mask; |
| }; |
| |
| class ir_copy_propagation_elements_visitor : public ir_rvalue_visitor { |
| public: |
| ir_copy_propagation_elements_visitor() |
| { |
| this->progress = false; |
| this->killed_all = false; |
| this->mem_ctx = ralloc_context(NULL); |
| this->shader_mem_ctx = NULL; |
| this->acp = new(mem_ctx) exec_list; |
| this->kills = new(mem_ctx) exec_list; |
| } |
| ~ir_copy_propagation_elements_visitor() |
| { |
| ralloc_free(mem_ctx); |
| } |
| |
| virtual ir_visitor_status visit_enter(class ir_loop *); |
| virtual ir_visitor_status visit_enter(class ir_function_signature *); |
| virtual ir_visitor_status visit_leave(class ir_assignment *); |
| virtual ir_visitor_status visit_enter(class ir_call *); |
| virtual ir_visitor_status visit_enter(class ir_if *); |
| virtual ir_visitor_status visit_leave(class ir_swizzle *); |
| |
| void handle_rvalue(ir_rvalue **rvalue); |
| |
| void add_copy(ir_assignment *ir); |
| void kill(kill_entry *k); |
| void handle_if_block(exec_list *instructions); |
| |
| /** List of acp_entry: The available copies to propagate */ |
| exec_list *acp; |
| /** |
| * List of kill_entry: The variables whose values were killed in this |
| * block. |
| */ |
| exec_list *kills; |
| |
| bool progress; |
| |
| bool killed_all; |
| |
| /* Context for our local data structures. */ |
| void *mem_ctx; |
| /* Context for allocating new shader nodes. */ |
| void *shader_mem_ctx; |
| }; |
| |
| } /* unnamed namespace */ |
| |
| ir_visitor_status |
| ir_copy_propagation_elements_visitor::visit_enter(ir_function_signature *ir) |
| { |
| /* Treat entry into a function signature as a completely separate |
| * block. Any instructions at global scope will be shuffled into |
| * main() at link time, so they're irrelevant to us. |
| */ |
| exec_list *orig_acp = this->acp; |
| exec_list *orig_kills = this->kills; |
| bool orig_killed_all = this->killed_all; |
| |
| this->acp = new(mem_ctx) exec_list; |
| this->kills = new(mem_ctx) exec_list; |
| this->killed_all = false; |
| |
| visit_list_elements(this, &ir->body); |
| |
| this->kills = orig_kills; |
| this->acp = orig_acp; |
| this->killed_all = orig_killed_all; |
| |
| return visit_continue_with_parent; |
| } |
| |
| ir_visitor_status |
| ir_copy_propagation_elements_visitor::visit_leave(ir_assignment *ir) |
| { |
| ir_dereference_variable *lhs = ir->lhs->as_dereference_variable(); |
| ir_variable *var = ir->lhs->variable_referenced(); |
| |
| if (var->type->is_scalar() || var->type->is_vector()) { |
| kill_entry *k; |
| |
| if (lhs) |
| k = new(mem_ctx) kill_entry(var, ir->write_mask); |
| else |
| k = new(mem_ctx) kill_entry(var, ~0); |
| |
| kill(k); |
| } |
| |
| add_copy(ir); |
| |
| return visit_continue; |
| } |
| |
| ir_visitor_status |
| ir_copy_propagation_elements_visitor::visit_leave(ir_swizzle *ir) |
| { |
| /* Don't visit the values of swizzles since they are handled while |
| * visiting the swizzle itself. |
| */ |
| return visit_continue; |
| } |
| |
| /** |
| * Replaces dereferences of ACP RHS variables with ACP LHS variables. |
| * |
| * This is where the actual copy propagation occurs. Note that the |
| * rewriting of ir_dereference means that the ir_dereference instance |
| * must not be shared by multiple IR operations! |
| */ |
| void |
| ir_copy_propagation_elements_visitor::handle_rvalue(ir_rvalue **ir) |
| { |
| int swizzle_chan[4]; |
| ir_dereference_variable *deref_var; |
| ir_variable *source[4] = {NULL, NULL, NULL, NULL}; |
| int source_chan[4]; |
| int chans; |
| |
| if (!*ir) |
| return; |
| |
| ir_swizzle *swizzle = (*ir)->as_swizzle(); |
| if (swizzle) { |
| deref_var = swizzle->val->as_dereference_variable(); |
| if (!deref_var) |
| return; |
| |
| swizzle_chan[0] = swizzle->mask.x; |
| swizzle_chan[1] = swizzle->mask.y; |
| swizzle_chan[2] = swizzle->mask.z; |
| swizzle_chan[3] = swizzle->mask.w; |
| chans = swizzle->type->vector_elements; |
| } else { |
| deref_var = (*ir)->as_dereference_variable(); |
| if (!deref_var) |
| return; |
| |
| swizzle_chan[0] = 0; |
| swizzle_chan[1] = 1; |
| swizzle_chan[2] = 2; |
| swizzle_chan[3] = 3; |
| chans = deref_var->type->vector_elements; |
| } |
| |
| if (this->in_assignee) |
| return; |
| |
| ir_variable *var = deref_var->var; |
| |
| /* Try to find ACP entries covering swizzle_chan[], hoping they're |
| * the same source variable. |
| */ |
| foreach_iter(exec_list_iterator, iter, *this->acp) { |
| acp_entry *entry = (acp_entry *)iter.get(); |
| |
| if (var == entry->lhs) { |
| for (int c = 0; c < chans; c++) { |
| if (entry->write_mask & (1 << swizzle_chan[c])) { |
| source[c] = entry->rhs; |
| source_chan[c] = entry->swizzle[swizzle_chan[c]]; |
| } |
| } |
| } |
| } |
| |
| /* Make sure all channels are copying from the same source variable. */ |
| if (!source[0]) |
| return; |
| for (int c = 1; c < chans; c++) { |
| if (source[c] != source[0]) |
| return; |
| } |
| |
| if (!shader_mem_ctx) |
| shader_mem_ctx = ralloc_parent(deref_var); |
| |
| if (debug) { |
| printf("Copy propagation from:\n"); |
| (*ir)->print(); |
| } |
| |
| deref_var = new(shader_mem_ctx) ir_dereference_variable(source[0]); |
| *ir = new(shader_mem_ctx) ir_swizzle(deref_var, |
| source_chan[0], |
| source_chan[1], |
| source_chan[2], |
| source_chan[3], |
| chans); |
| |
| if (debug) { |
| printf("to:\n"); |
| (*ir)->print(); |
| printf("\n"); |
| } |
| } |
| |
| |
| ir_visitor_status |
| ir_copy_propagation_elements_visitor::visit_enter(ir_call *ir) |
| { |
| /* Do copy propagation on call parameters, but skip any out params */ |
| exec_list_iterator sig_param_iter = ir->callee->parameters.iterator(); |
| foreach_iter(exec_list_iterator, iter, ir->actual_parameters) { |
| ir_variable *sig_param = (ir_variable *)sig_param_iter.get(); |
| ir_instruction *ir = (ir_instruction *)iter.get(); |
| if (sig_param->mode != ir_var_out && sig_param->mode != ir_var_inout) { |
| ir->accept(this); |
| } |
| sig_param_iter.next(); |
| } |
| |
| /* Since we're unlinked, we don't (necessarily) know the side effects of |
| * this call. So kill all copies. |
| */ |
| acp->make_empty(); |
| this->killed_all = true; |
| |
| return visit_continue_with_parent; |
| } |
| |
| void |
| ir_copy_propagation_elements_visitor::handle_if_block(exec_list *instructions) |
| { |
| exec_list *orig_acp = this->acp; |
| exec_list *orig_kills = this->kills; |
| bool orig_killed_all = this->killed_all; |
| |
| this->acp = new(mem_ctx) exec_list; |
| this->kills = new(mem_ctx) exec_list; |
| this->killed_all = false; |
| |
| /* Populate the initial acp with a copy of the original */ |
| foreach_iter(exec_list_iterator, iter, *orig_acp) { |
| acp_entry *a = (acp_entry *)iter.get(); |
| this->acp->push_tail(new(this->mem_ctx) acp_entry(a)); |
| } |
| |
| visit_list_elements(this, instructions); |
| |
| if (this->killed_all) { |
| orig_acp->make_empty(); |
| } |
| |
| exec_list *new_kills = this->kills; |
| this->kills = orig_kills; |
| this->acp = orig_acp; |
| this->killed_all = this->killed_all || orig_killed_all; |
| |
| /* Move the new kills into the parent block's list, removing them |
| * from the parent's ACP list in the process. |
| */ |
| foreach_list_safe(node, new_kills) { |
| kill_entry *k = (kill_entry *)node; |
| kill(k); |
| } |
| } |
| |
| ir_visitor_status |
| ir_copy_propagation_elements_visitor::visit_enter(ir_if *ir) |
| { |
| ir->condition->accept(this); |
| |
| handle_if_block(&ir->then_instructions); |
| handle_if_block(&ir->else_instructions); |
| |
| /* handle_if_block() already descended into the children. */ |
| return visit_continue_with_parent; |
| } |
| |
| ir_visitor_status |
| ir_copy_propagation_elements_visitor::visit_enter(ir_loop *ir) |
| { |
| exec_list *orig_acp = this->acp; |
| exec_list *orig_kills = this->kills; |
| bool orig_killed_all = this->killed_all; |
| |
| /* FINISHME: For now, the initial acp for loops is totally empty. |
| * We could go through once, then go through again with the acp |
| * cloned minus the killed entries after the first run through. |
| */ |
| this->acp = new(mem_ctx) exec_list; |
| this->kills = new(mem_ctx) exec_list; |
| this->killed_all = false; |
| |
| visit_list_elements(this, &ir->body_instructions); |
| |
| if (this->killed_all) { |
| orig_acp->make_empty(); |
| } |
| |
| exec_list *new_kills = this->kills; |
| this->kills = orig_kills; |
| this->acp = orig_acp; |
| this->killed_all = this->killed_all || orig_killed_all; |
| |
| foreach_list_safe(node, new_kills) { |
| kill_entry *k = (kill_entry *)node; |
| kill(k); |
| } |
| |
| /* already descended into the children. */ |
| return visit_continue_with_parent; |
| } |
| |
| /* Remove any entries currently in the ACP for this kill. */ |
| void |
| ir_copy_propagation_elements_visitor::kill(kill_entry *k) |
| { |
| foreach_list_safe(node, acp) { |
| acp_entry *entry = (acp_entry *)node; |
| |
| if (entry->lhs == k->var) { |
| entry->write_mask = entry->write_mask & ~k->write_mask; |
| if (entry->write_mask == 0) { |
| entry->remove(); |
| continue; |
| } |
| } |
| if (entry->rhs == k->var) { |
| entry->remove(); |
| } |
| } |
| |
| /* If we were on a list, remove ourselves before inserting */ |
| if (k->next) |
| k->remove(); |
| |
| this->kills->push_tail(k); |
| } |
| |
| /** |
| * Adds directly-copied channels between vector variables to the available |
| * copy propagation list. |
| */ |
| void |
| ir_copy_propagation_elements_visitor::add_copy(ir_assignment *ir) |
| { |
| acp_entry *entry; |
| int orig_swizzle[4] = {0, 1, 2, 3}; |
| int swizzle[4]; |
| |
| if (ir->condition) |
| return; |
| |
| ir_dereference_variable *lhs = ir->lhs->as_dereference_variable(); |
| if (!lhs || !(lhs->type->is_scalar() || lhs->type->is_vector())) |
| return; |
| |
| ir_dereference_variable *rhs = ir->rhs->as_dereference_variable(); |
| if (!rhs) { |
| ir_swizzle *swiz = ir->rhs->as_swizzle(); |
| if (!swiz) |
| return; |
| |
| rhs = swiz->val->as_dereference_variable(); |
| if (!rhs) |
| return; |
| |
| orig_swizzle[0] = swiz->mask.x; |
| orig_swizzle[1] = swiz->mask.y; |
| orig_swizzle[2] = swiz->mask.z; |
| orig_swizzle[3] = swiz->mask.w; |
| } |
| |
| /* Move the swizzle channels out to the positions they match in the |
| * destination. We don't want to have to rewrite the swizzle[] |
| * array every time we clear a bit of the write_mask. |
| */ |
| int j = 0; |
| for (int i = 0; i < 4; i++) { |
| if (ir->write_mask & (1 << i)) |
| swizzle[i] = orig_swizzle[j++]; |
| } |
| |
| int write_mask = ir->write_mask; |
| if (lhs->var == rhs->var) { |
| /* If this is a copy from the variable to itself, then we need |
| * to be sure not to include the updated channels from this |
| * instruction in the set of new source channels to be |
| * copy-propagated from. |
| */ |
| for (int i = 0; i < 4; i++) { |
| if (ir->write_mask & (1 << orig_swizzle[i])) |
| write_mask &= ~(1 << i); |
| } |
| } |
| |
| entry = new(this->mem_ctx) acp_entry(lhs->var, rhs->var, write_mask, |
| swizzle); |
| this->acp->push_tail(entry); |
| } |
| |
| bool |
| do_copy_propagation_elements(exec_list *instructions) |
| { |
| ir_copy_propagation_elements_visitor v; |
| |
| visit_list_elements(&v, instructions); |
| |
| return v.progress; |
| } |