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/*
* 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_texture_projection.cpp
*
* IR lower pass to perform the division of texture coordinates by the texture
* projector if present.
*
* Many GPUs have a texture sampling opcode that takes the projector
* and does the divide internally, thus the presence of the projector
* in the IR. For GPUs that don't, this saves the driver needing the
* logic for handling the divide.
*
* \author Eric Anholt <eric@anholt.net>
*/
#include "ir.h"
namespace {
class lower_texture_projection_visitor : public ir_hierarchical_visitor {
public:
lower_texture_projection_visitor()
{
progress = false;
}
ir_visitor_status visit_leave(ir_texture *ir);
bool progress;
};
} /* anonymous namespace */
ir_visitor_status
lower_texture_projection_visitor::visit_leave(ir_texture *ir)
{
if (!ir->projector)
return visit_continue;
void *mem_ctx = ralloc_parent(ir);
ir_variable *var = new(mem_ctx) ir_variable(ir->projector->type,
"projector", ir_var_temporary);
base_ir->insert_before(var);
ir_dereference *deref = new(mem_ctx) ir_dereference_variable(var);
ir_expression *expr = new(mem_ctx) ir_expression(ir_unop_rcp,
ir->projector->type,
ir->projector,
NULL);
ir_assignment *assign = new(mem_ctx) ir_assignment(deref, expr);
base_ir->insert_before(assign);
deref = new(mem_ctx) ir_dereference_variable(var);
ir->coordinate = new(mem_ctx) ir_expression(ir_binop_mul,
ir->coordinate->type,
ir->coordinate,
deref);
if (ir->shadow_comparator) {
deref = new(mem_ctx) ir_dereference_variable(var);
ir->shadow_comparator = new(mem_ctx) ir_expression(ir_binop_mul,
ir->shadow_comparator->type,
ir->shadow_comparator,
deref);
}
ir->projector = NULL;
progress = true;
return visit_continue;
}
bool
do_lower_texture_projection(exec_list *instructions)
{
lower_texture_projection_visitor v;
visit_list_elements(&v, instructions);
return v.progress;
}