[Mesa-dev] [PATCH 3/4] glsl: Merge if-simplification and conditional discard opt
Thomas Helland
thomashelland90 at gmail.com
Wed May 17 19:15:19 UTC 2017
The conditional discard pass is really just a form of if-simplification.
So there is no reason why we can not just merge the two, and avoid
running the visitor two times.
V2: Add back in the wrongly removed optimization
---
src/compiler/Makefile.sources | 1 -
src/compiler/glsl/glsl_parser_extras.cpp | 1 -
src/compiler/glsl/ir_optimization.h | 1 -
src/compiler/glsl/opt_conditional_discard.cpp | 99 ---------------------------
src/compiler/glsl/opt_if_simplification.cpp | 39 +++++++++++
5 files changed, 39 insertions(+), 102 deletions(-)
delete mode 100644 src/compiler/glsl/opt_conditional_discard.cpp
diff --git a/src/compiler/Makefile.sources b/src/compiler/Makefile.sources
index 611362ed73..964f454cca 100644
--- a/src/compiler/Makefile.sources
+++ b/src/compiler/Makefile.sources
@@ -114,7 +114,6 @@ LIBGLSL_FILES = \
glsl/lower_ubo_reference.cpp \
glsl/opt_algebraic.cpp \
glsl/opt_array_splitting.cpp \
- glsl/opt_conditional_discard.cpp \
glsl/opt_constant_folding.cpp \
glsl/opt_constant_propagation.cpp \
glsl/opt_constant_variable.cpp \
diff --git a/src/compiler/glsl/glsl_parser_extras.cpp b/src/compiler/glsl/glsl_parser_extras.cpp
index 218ce6949a..220c3a94ed 100644
--- a/src/compiler/glsl/glsl_parser_extras.cpp
+++ b/src/compiler/glsl/glsl_parser_extras.cpp
@@ -2176,7 +2176,6 @@ do_common_optimization(exec_list *ir, bool linked,
}
propagate_invariance(ir);
OPT(do_if_simplification, ir);
- OPT(opt_conditional_discard, ir);
OPT(do_copy_propagation, ir);
OPT(do_copy_propagation_elements, ir);
diff --git a/src/compiler/glsl/ir_optimization.h b/src/compiler/glsl/ir_optimization.h
index e9e705a1cc..7ffb47696c 100644
--- a/src/compiler/glsl/ir_optimization.h
+++ b/src/compiler/glsl/ir_optimization.h
@@ -96,7 +96,6 @@ bool ir_constant_fold(ir_rvalue **rvalue);
bool do_rebalance_tree(exec_list *instructions);
bool do_algebraic(exec_list *instructions, bool native_integers,
const struct gl_shader_compiler_options *options);
-bool opt_conditional_discard(exec_list *instructions);
bool do_constant_folding(exec_list *instructions);
bool do_constant_variable(exec_list *instructions);
bool do_constant_variable_unlinked(exec_list *instructions);
diff --git a/src/compiler/glsl/opt_conditional_discard.cpp b/src/compiler/glsl/opt_conditional_discard.cpp
deleted file mode 100644
index d7cb2069ed..0000000000
--- a/src/compiler/glsl/opt_conditional_discard.cpp
+++ /dev/null
@@ -1,99 +0,0 @@
-/*
- * Copyright © 2014 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_conditional_discard.cpp
- *
- * Replace
- *
- * if (cond) discard;
- *
- * with
- *
- * (discard <condition>)
- */
-
-#include "compiler/glsl_types.h"
-#include "ir.h"
-
-namespace {
-
-class opt_conditional_discard_visitor : public ir_hierarchical_visitor {
-public:
- opt_conditional_discard_visitor()
- {
- progress = false;
- }
-
- ir_visitor_status visit_leave(ir_if *);
- ir_visitor_status visit_enter(ir_assignment *);
-
- bool progress;
-};
-
-} /* anonymous namespace */
-
-/* We only care about the top level "if" instructions, so don't
- * descend into expressions.
- */
-ir_visitor_status
-opt_conditional_discard_visitor::visit_enter(ir_assignment *ir)
-{
- (void) ir;
- return visit_continue_with_parent;
-}
-
-bool
-opt_conditional_discard(exec_list *instructions)
-{
- opt_conditional_discard_visitor v;
- v.run(instructions);
- return v.progress;
-}
-
-ir_visitor_status
-opt_conditional_discard_visitor::visit_leave(ir_if *ir)
-{
- /* Look for "if (...) discard" with no else clause or extra statements. */
- if (ir->then_instructions.is_empty() ||
- !ir->then_instructions.get_head_raw()->next->is_tail_sentinel() ||
- !((ir_instruction *) ir->then_instructions.get_head_raw())->as_discard() ||
- !ir->else_instructions.is_empty())
- return visit_continue;
-
- /* Move the condition and replace the ir_if with the ir_discard. */
- ir_discard *discard = (ir_discard *) ir->then_instructions.get_head_raw();
- if (!discard->condition)
- discard->condition = ir->condition;
- else {
- void *ctx = ralloc_parent(ir);
- discard->condition = new(ctx) ir_expression(ir_binop_logic_and,
- ir->condition,
- discard->condition);
- }
- ir->replace_with(discard);
-
- progress = true;
-
- return visit_continue;
-}
diff --git a/src/compiler/glsl/opt_if_simplification.cpp b/src/compiler/glsl/opt_if_simplification.cpp
index 05159319ba..bcdda1061a 100644
--- a/src/compiler/glsl/opt_if_simplification.cpp
+++ b/src/compiler/glsl/opt_if_simplification.cpp
@@ -70,6 +70,40 @@ do_if_simplification(exec_list *instructions)
return v.made_progress;
}
+/**
+ *
+ * Replace
+ *
+ * if (cond) discard;
+ *
+ * with
+ *
+ * (discard <condition>)
+ */
+static bool
+opt_conditional_discard(ir_if *ir)
+{
+ /* Look for "if (...) discard" with no else clause or extra statements. */
+ if (ir->then_instructions.is_empty() ||
+ !ir->then_instructions.get_head_raw()->next->is_tail_sentinel() ||
+ !((ir_instruction *) ir->then_instructions.get_head_raw())->as_discard() ||
+ !ir->else_instructions.is_empty())
+ return visit_continue;
+
+ /* Move the condition and replace the ir_if with the ir_discard. */
+ ir_discard *discard = (ir_discard *) ir->then_instructions.get_head_raw();
+ if (!discard->condition)
+ discard->condition = ir->condition;
+ else {
+ void *ctx = ralloc_parent(ir);
+ discard->condition = new(ctx) ir_expression(ir_binop_logic_and,
+ ir->condition,
+ discard->condition);
+ }
+ ir->replace_with(discard);
+
+ return true;
+}
/**
*
@@ -116,6 +150,11 @@ ir_if_simplification_visitor::visit_leave(ir_if *ir)
if (opt_flatten_nested_if_blocks(ir))
this->made_progress = true;
+ if (opt_conditional_discard(ir)) {
+ this->made_progress = true;
+ return visit_continue;
+ }
+
/* If the if statement has nothing on either side, remove it. */
if (ir->then_instructions.is_empty() &&
ir->else_instructions.is_empty()) {
--
2.12.2
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