Switch to Mesa 7.9.

media-libs/mesa/files/7.9-add-lower-pass-discards.patch

+Port of the following to mesa 7.9:
+
+From 940df10100d740ef27fa39026fd51c3199ed3d62 Mon Sep 17 00:00:00 2001
+From: Kenneth Graunke <kenneth@whitecape.org>
+Date: Thu, 25 Nov 2010 09:09:26 +0000
+Subject: glsl: Add a lowering pass to move discards out of if-statements.
+
+This should allow lower_if_to_cond_assign to work in the presence of
+discards, fixing bug #31690 and likely #31983.
+
+NOTE: This is a candidate for the 7.9 branch.
+---
+diff -Naurp Mesa-7.9.orig/src/glsl/Makefile Mesa-7.9.work/src/glsl/Makefile
+--- Mesa-7.9.orig/src/glsl/Makefile     2010-12-07 18:22:17.511752000 -0800
++++ Mesa-7.9.work/src/glsl/Makefile     2010-12-10 16:15:41.026229000 -0800
+@@ -75,6 +75,7 @@ CXX_SOURCES = \
+        loop_analysis.cpp \
+        loop_controls.cpp \
+        loop_unroll.cpp \
++       lower_discard.cpp \
+        lower_noise.cpp \
+        lower_variable_index_to_cond_assign.cpp \
+        opt_redundant_jumps.cpp \
+diff -Naurp Mesa-7.9.orig/src/glsl/SConscript Mesa-7.9.work/src/glsl/SConscript
+--- Mesa-7.9.orig/src/glsl/SConscript   2010-12-07 18:22:17.518757000 -0800
++++ Mesa-7.9.work/src/glsl/SConscript   2010-12-10 16:16:28.878294000 -0800
+@@ -72,6 +72,7 @@ sources = [
+     'loop_analysis.cpp',
+     'loop_controls.cpp',
+     'loop_unroll.cpp',
++    'lower_discard.cpp',
+     'lower_noise.cpp',
+     'lower_variable_index_to_cond_assign.cpp',
+     'opt_redundant_jumps.cpp',
+diff -Naurp Mesa-7.9.orig/src/glsl/ir_optimization.h Mesa-7.9.work/src/glsl/ir_optimization.h
+--- Mesa-7.9.orig/src/glsl/ir_optimization.h    2010-12-07 18:22:17.556757000 -0800
++++ Mesa-7.9.work/src/glsl/ir_optimization.h    2010-12-10 16:34:56.074610000 -0800
+@@ -55,6 +55,7 @@ bool do_swizzle_swizzle(exec_list *instr
+ bool do_tree_grafting(exec_list *instructions);
+ bool do_vec_index_to_cond_assign(exec_list *instructions);
+ bool do_vec_index_to_swizzle(exec_list *instructions);
++bool lower_discard(exec_list *instructions);
+ bool lower_noise(exec_list *instructions);
+ bool lower_variable_index_to_cond_assign(exec_list *instructions,
+     bool lower_input, bool lower_output, bool lower_temp, bool lower_uniform);
+diff -Naurp Mesa-7.9.orig/src/glsl/lower_discard.cpp Mesa-7.9.work/src/glsl/lower_discard.cpp
+--- Mesa-7.9.orig/src/glsl/lower_discard.cpp    1969-12-31 16:00:00.000000000 -0800
++++ Mesa-7.9.work/src/glsl/lower_discard.cpp    2010-12-10 16:15:16.494214000 -0800
+@@ -0,0 +1,198 @@
++/*
++ * 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 lower_discard.cpp
++ *
++ * This pass moves discards out of if-statements.
++ *
++ * Case 1: The "then" branch contains a conditional discard:
++ * ---------------------------------------------------------
++ *
++ *    if (cond1) {
++ *      s1;
++ *      discard cond2;
++ *      s2;
++ *    } else {
++ *      s3;
++ *    }
++ *
++ * becomes:
++ *
++ *    temp = false;
++ *    if (cond1) {
++ *      s1;
++ *      temp = cond2;
++ *      s2;
++ *    } else {
++ *      s3;
++ *    }
++ *    discard temp;
++ *
++ * Case 2: The "else" branch contains a conditional discard:
++ * ---------------------------------------------------------
++ *
++ *    if (cond1) {
++ *      s1;
++ *    } else {
++ *      s2;
++ *      discard cond2;
++ *      s3;
++ *    }
++ *
++ * becomes:
++ *
++ *    temp = false;
++ *    if (cond1) {
++ *      s1;
++ *    } else {
++ *      s2;
++ *      temp = cond2;
++ *      s3;
++ *    }
++ *    discard temp;
++ *
++ * Case 3: Both branches contain a conditional discard:
++ * ----------------------------------------------------
++ *
++ *    if (cond1) {
++ *      s1;
++ *      discard cond2;
++ *      s2;
++ *    } else {
++ *      s3;
++ *      discard cond3;
++ *      s4;
++ *    }
++ *
++ * becomes:
++ *
++ *    temp = false;
++ *    if (cond1) {
++ *      s1;
++ *      temp = cond2;
++ *      s2;
++ *    } else {
++ *      s3;
++ *      temp = cond3;
++ *      s4;
++ *    }
++ *    discard temp;
++ *
++ * If there are multiple conditional discards, we need only deal with one of
++ * them.  Repeatedly applying this pass will take care of the others.
++ *
++ * Unconditional discards are treated as having a condition of "true".
++ */
++
++#include "glsl_types.h"
++#include "ir.h"
++
++class lower_discard_visitor : public ir_hierarchical_visitor {
++public:
++   lower_discard_visitor()
++   {
++      this->progress = false;
++   }
++
++   ir_visitor_status visit_leave(ir_if *);
++
++   bool progress;
++};
++
++
++bool
++lower_discard(exec_list *instructions)
++{
++   lower_discard_visitor v;
++
++   visit_list_elements(&v, instructions);
++
++   return v.progress;
++}
++
++
++static ir_discard *
++find_discard(exec_list &instructions)
++{
++   foreach_list(n, &instructions) {
++      ir_discard *ir = ((ir_instruction *) n)->as_discard();
++      if (ir != NULL)
++        return ir;
++   }
++   return NULL;
++}
++
++
++static void
++replace_discard(void *mem_ctx, ir_variable *var, ir_discard *ir)
++{
++   ir_rvalue *condition = ir->condition;
++
++   /* For unconditional discards, use "true" as the condition. */
++   if (condition == NULL)
++      condition = new(mem_ctx) ir_constant(true);
++
++   ir_assignment *assignment =
++      new(mem_ctx) ir_assignment(new(mem_ctx) ir_dereference_variable(var),
++                                condition, NULL);
++
++   ir->replace_with(assignment);
++}
++
++
++ir_visitor_status
++lower_discard_visitor::visit_leave(ir_if *ir)
++{
++   ir_discard *then_discard = find_discard(ir->then_instructions);
++   ir_discard *else_discard = find_discard(ir->else_instructions);
++
++   if (then_discard == NULL && else_discard == NULL)
++      return visit_continue;
++
++   void *mem_ctx = talloc_parent(ir);
++
++   ir_variable *temp = new(mem_ctx) ir_variable(glsl_type::bool_type,
++                                               "discard_cond_temp",
++                                               ir_var_temporary);
++   ir_assignment *temp_initializer =
++      new(mem_ctx) ir_assignment(new(mem_ctx) ir_dereference_variable(temp),
++                                new(mem_ctx) ir_constant(false), NULL);
++
++   ir->insert_before(temp);
++   ir->insert_before(temp_initializer);
++
++   if (then_discard != NULL)
++      replace_discard(mem_ctx, temp, then_discard);
++
++   if (else_discard != NULL)
++      replace_discard(mem_ctx, temp, else_discard);
++
++   ir_discard *discard = then_discard != NULL ? then_discard : else_discard;
++   discard->condition = new(mem_ctx) ir_dereference_variable(temp);
++   ir->insert_after(discard);
++
++   this->progress = true;
++
++   return visit_continue;
++}
+diff -Naurp Mesa-7.9.orig/src/mesa/program/ir_to_mesa.cpp Mesa-7.9.work/src/mesa/program/ir_to_mesa.cpp
+--- Mesa-7.9.orig/src/mesa/program/ir_to_mesa.cpp       2010-12-07 18:22:19.954589000 -0800
++++ Mesa-7.9.work/src/mesa/program/ir_to_mesa.cpp       2010-12-10 16:15:16.555205000 -0800
+@@ -2780,8 +2780,10 @@ _mesa_ir_link_shader(GLcontext *ctx, str
+ 
+         progress = do_common_optimization(ir, true, options->MaxUnrollIterations) || progress;
+ 
+-        if (options->EmitNoIfs)
++        if (options->EmitNoIfs) {
++           progress = lower_discard(ir) || progress;
+            progress = do_if_to_cond_assign(ir) || progress;
++        }
+ 
+         if (options->EmitNoNoise)
+            progress = lower_noise(ir) || progress;