diff options
Diffstat (limited to 'mesalib/src/glsl/opt_discard_simplification.cpp')
| -rw-r--r-- | mesalib/src/glsl/opt_discard_simplification.cpp | 205 |
1 files changed, 0 insertions, 205 deletions
diff --git a/mesalib/src/glsl/opt_discard_simplification.cpp b/mesalib/src/glsl/opt_discard_simplification.cpp deleted file mode 100644 index ba4981bae..000000000 --- a/mesalib/src/glsl/opt_discard_simplification.cpp +++ /dev/null @@ -1,205 +0,0 @@ -/* - * 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_discard_simplification.cpp - * - * This pass simplifies if-statements and loops containing unconditional - * discards. - * - * Case 1: Both branches contain unconditional discards: - * ----------------------------------------------------- - * - * if (cond) { - * s1; - * discard; - * s2; - * } else { - * s3; - * discard; - * s4; - * } - * - * becomes: - * - * discard - * - * Case 2: The "then" clause contains an unconditional discard: - * ------------------------------------------------------------ - * - * if (cond) { - * s1; - * discard; - * s2; - * } else { - * s3; - * } - * - * becomes: - * - * if (cond) { - * discard; - * } else { - * s3; - * } - * - * Case 3: The "else" clause contains an unconditional discard: - * ------------------------------------------------------------ - * - * if (cond) { - * s1; - * } else { - * s2; - * discard; - * s3; - * } - * - * becomes: - * - * if (cond) { - * s1; - * } else { - * discard; - * } - */ - -#include "glsl_types.h" -#include "ir.h" - -class discard_simplifier : public ir_hierarchical_visitor { -public: - discard_simplifier() - { - this->progress = false; - } - - ir_visitor_status visit_enter(ir_if *); - ir_visitor_status visit_enter(ir_loop *); - ir_visitor_status visit_enter(ir_assignment *); - - bool progress; -}; - -static ir_discard * -find_unconditional_discard(exec_list &instructions) -{ - foreach_list(n, &instructions) { - ir_instruction *ir = (ir_instruction *)n; - - if (ir->ir_type == ir_type_return || - ir->ir_type == ir_type_loop_jump) - return NULL; - - /* So far, this code doesn't know how to look inside of flow - * control to see if a discard later on at this level is - * unconditional. - */ - if (ir->ir_type == ir_type_if || - ir->ir_type == ir_type_loop) - return NULL; - - ir_discard *discard = ir->as_discard(); - if (discard != NULL && discard->condition == NULL) - return discard; - } - return NULL; -} - -static bool -is_only_instruction(ir_discard *discard) -{ - return (discard->prev->is_head_sentinel() && - discard->next->is_tail_sentinel()); -} - -/* We only care about the top level instructions, so don't descend - * into expressions. - */ -ir_visitor_status -discard_simplifier::visit_enter(ir_assignment *ir) -{ - (void) ir; - return visit_continue_with_parent; -} - -ir_visitor_status -discard_simplifier::visit_enter(ir_if *ir) -{ - ir_discard *then_discard = find_unconditional_discard(ir->then_instructions); - ir_discard *else_discard = find_unconditional_discard(ir->else_instructions); - - if (then_discard == NULL && else_discard == NULL) - return visit_continue; - - /* If both branches result in discard, replace whole if with discard. */ - if (then_discard != NULL && else_discard != NULL) { - this->progress = true; - ir->replace_with(then_discard); - return visit_continue_with_parent; - } - - /* Otherwise, one branch has a discard. */ - if (then_discard != NULL && !is_only_instruction(then_discard)) { - this->progress = true; - ir->then_instructions.make_empty(); - ir->then_instructions.push_tail(then_discard); - } else if (else_discard != NULL && !is_only_instruction(else_discard)) { - this->progress = true; - ir->else_instructions.make_empty(); - ir->else_instructions.push_tail(else_discard); - } - - visit_list_elements(this, &ir->then_instructions); - return visit_continue_with_parent; -} - -ir_visitor_status -discard_simplifier::visit_enter(ir_loop *ir) -{ - ir_discard *discard = find_unconditional_discard(ir->body_instructions); - - if (discard) { - ir->replace_with(discard); - return visit_continue_with_parent; - } - - return visit_continue; -} - -bool -do_discard_simplification(exec_list *instructions) -{ - /* Look for a top-level unconditional discard */ - ir_discard *discard = find_unconditional_discard(*instructions); - if (discard != NULL) { - instructions->make_empty(); - instructions->push_tail(discard); - return true; - } - - discard_simplifier v; - - visit_list_elements(&v, instructions); - - return v.progress; -} |