diff options
| -rw-r--r-- | src/glsl/ir_copy_propagation.cpp | 248 |
1 files changed, 158 insertions, 90 deletions
diff --git a/src/glsl/ir_copy_propagation.cpp b/src/glsl/ir_copy_propagation.cpp index 90a49d5a82a..6c211f0e70a 100644 --- a/src/glsl/ir_copy_propagation.cpp +++ b/src/glsl/ir_copy_propagation.cpp @@ -25,7 +25,7 @@ * \file ir_copy_propagation.cpp * * Moves usage of recently-copied variables to the previous copy of - * the variable within basic blocks. + * the variable. * * This should reduce the number of MOV instructions in the generated * programs unless copy propagation is also done on the LIR, and may @@ -53,13 +53,31 @@ public: ir_variable *rhs; }; + +class kill_entry : public exec_node +{ +public: + kill_entry(ir_variable *var) + { + assert(var); + this->var = var; + } + + ir_variable *var; +}; + class ir_copy_propagation_visitor : public ir_hierarchical_visitor { public: - ir_copy_propagation_visitor(exec_list *acp) + ir_copy_propagation_visitor() { progress = false; - in_lhs = false; - this->acp = acp; + mem_ctx = talloc_new(0); + this->acp = new(mem_ctx) exec_list; + this->kills = new(mem_ctx) exec_list; + } + ~ir_copy_propagation_visitor() + { + talloc_free(mem_ctx); } virtual ir_visitor_status visit(class ir_dereference_variable *); @@ -70,26 +88,46 @@ public: virtual ir_visitor_status visit_enter(class ir_call *); virtual ir_visitor_status visit_enter(class ir_if *); - /** List of acp_entry */ + void add_copy(ir_assignment *ir); + void kill(ir_variable *ir); + void handle_if_block(exec_list *instructions); + + /** List of acp_entry: The available copies to propagate */ exec_list *acp; - bool progress; + /** + * List of kill_entry: The variables whose values were killed in this + * block. + */ + exec_list *kills; - /** Currently in the LHS of an assignment? */ - bool in_lhs; -}; + bool progress; + bool killed_all; -ir_visitor_status -ir_copy_propagation_visitor::visit_enter(ir_loop *ir) -{ - (void)ir; - return visit_continue_with_parent; -} + void *mem_ctx; +}; ir_visitor_status ir_copy_propagation_visitor::visit_enter(ir_function_signature *ir) { - (void)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; } @@ -98,34 +136,33 @@ ir_copy_propagation_visitor::visit_enter(ir_assignment *ir) { ir_visitor_status s; - /* Inline the rest of ir_assignment::accept(ir_hv *v), wrapping the - * LHS part with setting in_lhs so that we can avoid copy - * propagating into the LHS. + /* ir_assignment::accept(ir_hv *v), skipping the LHS so that we can + * avoid copy propagating into the LHS. * * Note that this means we won't copy propagate into the derefs of * an array index. Oh well. */ - this->in_lhs = true; - s = ir->lhs->accept(this); - this->in_lhs = false; - if (s != visit_continue) - return (s == visit_continue_with_parent) ? visit_continue : s; s = ir->rhs->accept(this); - if (s != visit_continue) - return (s == visit_continue_with_parent) ? visit_continue : s; + assert(s == visit_continue); - if (ir->condition) + if (ir->condition) { s = ir->condition->accept(this); + assert(s == visit_continue); + } + + kill(ir->lhs->variable_referenced()); - return (s == visit_stop) ? s : visit_continue_with_parent; + add_copy(ir); + + return visit_continue_with_parent; } ir_visitor_status ir_copy_propagation_visitor::visit_enter(ir_function *ir) { (void) ir; - return visit_continue_with_parent; + return visit_continue; } /** @@ -138,14 +175,7 @@ ir_copy_propagation_visitor::visit_enter(ir_function *ir) ir_visitor_status ir_copy_propagation_visitor::visit(ir_dereference_variable *ir) { - /* Ignores the LHS. Don't want to rewrite the LHS to point at some - * other storage! - */ - if (this->in_lhs) { - return visit_continue; - } - - ir_variable *var = ir->variable_referenced(); + ir_variable *var = ir->var; foreach_iter(exec_list_iterator, iter, *this->acp) { acp_entry *entry = (acp_entry *)iter.get(); @@ -169,43 +199,108 @@ ir_copy_propagation_visitor::visit_enter(ir_call *ir) 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 && - sig_param->mode != ir_var_uniform) { + 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 (necssarily) 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_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->lhs, a->rhs)); + } + + 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; + + foreach_iter(exec_list_iterator, iter, *new_kills) { + kill_entry *k = (kill_entry *)iter.get(); + kill(k->var); + } +} ir_visitor_status ir_copy_propagation_visitor::visit_enter(ir_if *ir) { ir->condition->accept(this); - /* Do not traverse into the body of the if-statement since that is a - * different basic block. - */ + 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; } -static bool -propagate_copies(ir_instruction *ir, exec_list *acp) +ir_visitor_status +ir_copy_propagation_visitor::visit_enter(ir_loop *ir) { - ir_copy_propagation_visitor v(acp); + exec_list *orig_acp = this->acp; + exec_list *orig_kills = this->kills; + bool orig_killed_all = this->killed_all; - ir->accept(&v); + /* 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; - return v.progress; + 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_iter(exec_list_iterator, iter, *new_kills) { + kill_entry *k = (kill_entry *)iter.get(); + kill(k->var); + } + + /* already descended into the children. */ + return visit_continue_with_parent; } -static void -kill_invalidated_copies(ir_assignment *ir, exec_list *acp) +void +ir_copy_propagation_visitor::kill(ir_variable *var) { - ir_variable *var = ir->lhs->variable_referenced(); assert(var != NULL); + /* Remove any entries currently in the ACP for this kill. */ foreach_iter(exec_list_iterator, iter, *acp) { acp_entry *entry = (acp_entry *)iter.get(); @@ -213,21 +308,25 @@ kill_invalidated_copies(ir_assignment *ir, exec_list *acp) entry->remove(); } } + + /* Add the LHS variable to the list of killed variables in this block. + */ + this->kills->push_tail(new(this->mem_ctx) kill_entry(var)); } /** * Adds an entry to the available copy list if it's a plain assignment * of a variable to a variable. */ -static bool -add_copy(void *ctx, ir_assignment *ir, exec_list *acp) +void +ir_copy_propagation_visitor::add_copy(ir_assignment *ir) { acp_entry *entry; if (ir->condition) { ir_constant *condition = ir->condition->as_constant(); if (!condition || !condition->value.b[0]) - return false; + return; } ir_variable *lhs_var = ir->whole_variable_written(); @@ -241,43 +340,12 @@ add_copy(void *ctx, ir_assignment *ir, exec_list *acp) * will clean up the mess. */ ir->condition = new(talloc_parent(ir)) ir_constant(false); - return true; + this->progress = true; } else { - entry = new(ctx) acp_entry(lhs_var, rhs_var); - acp->push_tail(entry); + entry = new(this->mem_ctx) acp_entry(lhs_var, rhs_var); + this->acp->push_tail(entry); } } - - return false; -} - -static void -copy_propagation_basic_block(ir_instruction *first, - ir_instruction *last, - void *data) -{ - ir_instruction *ir; - /* List of avaialble_copy */ - exec_list acp; - bool *out_progress = (bool *)data; - bool progress = false; - - void *ctx = talloc_new(NULL); - for (ir = first;; ir = (ir_instruction *)ir->next) { - ir_assignment *ir_assign = ir->as_assignment(); - - progress = propagate_copies(ir, &acp) || progress; - - if (ir_assign) { - kill_invalidated_copies(ir_assign, &acp); - - progress = add_copy(ctx, ir_assign, &acp) || progress; - } - if (ir == last) - break; - } - *out_progress = progress; - talloc_free(ctx); } /** @@ -286,9 +354,9 @@ copy_propagation_basic_block(ir_instruction *first, bool do_copy_propagation(exec_list *instructions) { - bool progress = false; + ir_copy_propagation_visitor v; - call_for_basic_blocks(instructions, copy_propagation_basic_block, &progress); + visit_list_elements(&v, instructions); - return progress; + return v.progress; } |