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authormarha <marha@users.sourceforge.net>2012-05-15 15:02:37 +0200
committermarha <marha@users.sourceforge.net>2012-05-15 15:02:37 +0200
commit062c45ff0df6a52080dcd74433710d47127cbe29 (patch)
treeb038a5498555dfc9adf695c49d185f9414056931 /mesalib/src/glsl/opt_discard_simplification.cpp
parent1a71b50696cc230cd055905a5f9fdbd3fa7c89af (diff)
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xserver mesa git update 15 May 2012
Diffstat (limited to 'mesalib/src/glsl/opt_discard_simplification.cpp')
-rw-r--r--mesalib/src/glsl/opt_discard_simplification.cpp205
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
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--- 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;
-}