mesa/src/glsl/ir_hv_accept.cpp
Kenneth Graunke d884f60861 glsl: Convert ir_call to be a statement rather than a value.
Aside from ir_call, our IR is cleanly split into two classes:
- Statements (typeless; used for side effects, control flow)
- Values (deeply nestable, pure, typed expression trees)

Unfortunately, ir_call confused all this:
- For void functions, we placed ir_call directly in the instruction
  stream, treating it as an untyped statement.  Yet, it was a subclass
  of ir_rvalue, and no other ir_rvalue could be used in this way.
- For functions with a return value, ir_call could be placed in
  arbitrary expression trees.  While this fit naturally with the source
  language, it meant that expressions might not be pure, making it
  difficult to transform and optimize them.  To combat this, we always
  emitted ir_call directly in the RHS of an ir_assignment, only using
  a temporary variable in expression trees.  Many passes relied on this
  assumption; the acos and atan built-ins violated it.

This patch makes ir_call a statement (ir_instruction) rather than a
value (ir_rvalue).  Non-void calls now take a ir_dereference of a
variable, and store the return value there---effectively a call and
assignment rolled into one.  They cannot be embedded in expressions.

All expression trees are now pure, without exception.

Signed-off-by: Kenneth Graunke <kenneth@whitecape.org>
Reviewed-by: Eric Anholt <eric@anholt.net>
Reviewed-by: Ian Romanick <ian.d.romanick@intel.com>
2012-04-02 14:15:41 -07:00

411 lines
11 KiB
C++

/*
* 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.
*/
#include "ir.h"
/**
* \file ir_hv_accept.cpp
* Implementations of all hierarchical visitor accept methods for IR
* instructions.
*/
/**
* Process a list of nodes using a hierarchical vistor.
*
* If statement_list is true (the default), this is a list of statements, so
* v->base_ir will be set to point to each statement just before iterating
* over it, and restored after iteration is complete. If statement_list is
* false, this is a list that appears inside a statement (e.g. a parameter
* list), so v->base_ir will be left alone.
*
* \warning
* This function will operate correctly if a node being processed is removed
* from the list. However, if nodes are added to the list after the node being
* processed, some of the added nodes may not be processed.
*/
ir_visitor_status
visit_list_elements(ir_hierarchical_visitor *v, exec_list *l,
bool statement_list)
{
ir_instruction *prev_base_ir = v->base_ir;
foreach_list_safe(n, l) {
ir_instruction *const ir = (ir_instruction *) n;
if (statement_list)
v->base_ir = ir;
ir_visitor_status s = ir->accept(v);
if (s != visit_continue)
return s;
}
if (statement_list)
v->base_ir = prev_base_ir;
return visit_continue;
}
ir_visitor_status
ir_rvalue::accept(ir_hierarchical_visitor *v)
{
return v->visit(this);
}
ir_visitor_status
ir_variable::accept(ir_hierarchical_visitor *v)
{
return v->visit(this);
}
ir_visitor_status
ir_loop::accept(ir_hierarchical_visitor *v)
{
ir_visitor_status s = v->visit_enter(this);
if (s != visit_continue)
return (s == visit_continue_with_parent) ? visit_continue : s;
s = visit_list_elements(v, &this->body_instructions);
if (s == visit_stop)
return s;
if (s != visit_continue_with_parent) {
if (this->from) {
s = this->from->accept(v);
if (s != visit_continue)
return (s == visit_continue_with_parent) ? visit_continue : s;
}
if (this->to) {
s = this->to->accept(v);
if (s != visit_continue)
return (s == visit_continue_with_parent) ? visit_continue : s;
}
if (this->increment) {
s = this->increment->accept(v);
if (s != visit_continue)
return (s == visit_continue_with_parent) ? visit_continue : s;
}
}
return v->visit_leave(this);
}
ir_visitor_status
ir_loop_jump::accept(ir_hierarchical_visitor *v)
{
return v->visit(this);
}
ir_visitor_status
ir_function_signature::accept(ir_hierarchical_visitor *v)
{
ir_visitor_status s = v->visit_enter(this);
if (s != visit_continue)
return (s == visit_continue_with_parent) ? visit_continue : s;
s = visit_list_elements(v, &this->parameters);
if (s == visit_stop)
return s;
s = visit_list_elements(v, &this->body);
return (s == visit_stop) ? s : v->visit_leave(this);
}
ir_visitor_status
ir_function::accept(ir_hierarchical_visitor *v)
{
ir_visitor_status s = v->visit_enter(this);
if (s != visit_continue)
return (s == visit_continue_with_parent) ? visit_continue : s;
s = visit_list_elements(v, &this->signatures, false);
return (s == visit_stop) ? s : v->visit_leave(this);
}
ir_visitor_status
ir_expression::accept(ir_hierarchical_visitor *v)
{
ir_visitor_status s = v->visit_enter(this);
if (s != visit_continue)
return (s == visit_continue_with_parent) ? visit_continue : s;
for (unsigned i = 0; i < this->get_num_operands(); i++) {
switch (this->operands[i]->accept(v)) {
case visit_continue:
break;
case visit_continue_with_parent:
// I wish for Java's labeled break-statement here.
goto done;
case visit_stop:
return s;
}
}
done:
return v->visit_leave(this);
}
ir_visitor_status
ir_texture::accept(ir_hierarchical_visitor *v)
{
ir_visitor_status s = v->visit_enter(this);
if (s != visit_continue)
return (s == visit_continue_with_parent) ? visit_continue : s;
s = this->sampler->accept(v);
if (s != visit_continue)
return (s == visit_continue_with_parent) ? visit_continue : s;
if (this->coordinate) {
s = this->coordinate->accept(v);
if (s != visit_continue)
return (s == visit_continue_with_parent) ? visit_continue : s;
}
if (this->projector) {
s = this->projector->accept(v);
if (s != visit_continue)
return (s == visit_continue_with_parent) ? visit_continue : s;
}
if (this->shadow_comparitor) {
s = this->shadow_comparitor->accept(v);
if (s != visit_continue)
return (s == visit_continue_with_parent) ? visit_continue : s;
}
if (this->offset) {
s = this->offset->accept(v);
if (s != visit_continue)
return (s == visit_continue_with_parent) ? visit_continue : s;
}
switch (this->op) {
case ir_tex:
break;
case ir_txb:
s = this->lod_info.bias->accept(v);
if (s != visit_continue)
return (s == visit_continue_with_parent) ? visit_continue : s;
break;
case ir_txl:
case ir_txf:
case ir_txs:
s = this->lod_info.lod->accept(v);
if (s != visit_continue)
return (s == visit_continue_with_parent) ? visit_continue : s;
break;
case ir_txd:
s = this->lod_info.grad.dPdx->accept(v);
if (s != visit_continue)
return (s == visit_continue_with_parent) ? visit_continue : s;
s = this->lod_info.grad.dPdy->accept(v);
if (s != visit_continue)
return (s == visit_continue_with_parent) ? visit_continue : s;
break;
}
return (s == visit_stop) ? s : v->visit_leave(this);
}
ir_visitor_status
ir_swizzle::accept(ir_hierarchical_visitor *v)
{
ir_visitor_status s = v->visit_enter(this);
if (s != visit_continue)
return (s == visit_continue_with_parent) ? visit_continue : s;
s = this->val->accept(v);
return (s == visit_stop) ? s : v->visit_leave(this);
}
ir_visitor_status
ir_dereference_variable::accept(ir_hierarchical_visitor *v)
{
return v->visit(this);
}
ir_visitor_status
ir_dereference_array::accept(ir_hierarchical_visitor *v)
{
ir_visitor_status s = v->visit_enter(this);
if (s != visit_continue)
return (s == visit_continue_with_parent) ? visit_continue : s;
/* The array index is not the target of the assignment, so clear the
* 'in_assignee' flag. Restore it after returning from the array index.
*/
const bool was_in_assignee = v->in_assignee;
v->in_assignee = false;
s = this->array_index->accept(v);
v->in_assignee = was_in_assignee;
if (s != visit_continue)
return (s == visit_continue_with_parent) ? visit_continue : s;
s = this->array->accept(v);
return (s == visit_stop) ? s : v->visit_leave(this);
}
ir_visitor_status
ir_dereference_record::accept(ir_hierarchical_visitor *v)
{
ir_visitor_status s = v->visit_enter(this);
if (s != visit_continue)
return (s == visit_continue_with_parent) ? visit_continue : s;
s = this->record->accept(v);
return (s == visit_stop) ? s : v->visit_leave(this);
}
ir_visitor_status
ir_assignment::accept(ir_hierarchical_visitor *v)
{
ir_visitor_status s = v->visit_enter(this);
if (s != visit_continue)
return (s == visit_continue_with_parent) ? visit_continue : s;
v->in_assignee = true;
s = this->lhs->accept(v);
v->in_assignee = false;
if (s != visit_continue)
return (s == visit_continue_with_parent) ? visit_continue : s;
s = this->rhs->accept(v);
if (s != visit_continue)
return (s == visit_continue_with_parent) ? visit_continue : s;
if (this->condition)
s = this->condition->accept(v);
return (s == visit_stop) ? s : v->visit_leave(this);
}
ir_visitor_status
ir_constant::accept(ir_hierarchical_visitor *v)
{
return v->visit(this);
}
ir_visitor_status
ir_call::accept(ir_hierarchical_visitor *v)
{
ir_visitor_status s = v->visit_enter(this);
if (s != visit_continue)
return (s == visit_continue_with_parent) ? visit_continue : s;
if (this->return_deref != NULL) {
v->in_assignee = true;
s = this->return_deref->accept(v);
v->in_assignee = false;
if (s != visit_continue)
return (s == visit_continue_with_parent) ? visit_continue : s;
}
s = visit_list_elements(v, &this->actual_parameters, false);
if (s == visit_stop)
return s;
return v->visit_leave(this);
}
ir_visitor_status
ir_return::accept(ir_hierarchical_visitor *v)
{
ir_visitor_status s = v->visit_enter(this);
if (s != visit_continue)
return (s == visit_continue_with_parent) ? visit_continue : s;
ir_rvalue *val = this->get_value();
if (val) {
s = val->accept(v);
if (s != visit_continue)
return (s == visit_continue_with_parent) ? visit_continue : s;
}
return v->visit_leave(this);
}
ir_visitor_status
ir_discard::accept(ir_hierarchical_visitor *v)
{
ir_visitor_status s = v->visit_enter(this);
if (s != visit_continue)
return (s == visit_continue_with_parent) ? visit_continue : s;
if (this->condition != NULL) {
s = this->condition->accept(v);
if (s != visit_continue)
return (s == visit_continue_with_parent) ? visit_continue : s;
}
return v->visit_leave(this);
}
ir_visitor_status
ir_if::accept(ir_hierarchical_visitor *v)
{
ir_visitor_status s = v->visit_enter(this);
if (s != visit_continue)
return (s == visit_continue_with_parent) ? visit_continue : s;
s = this->condition->accept(v);
if (s != visit_continue)
return (s == visit_continue_with_parent) ? visit_continue : s;
if (s != visit_continue_with_parent) {
s = visit_list_elements(v, &this->then_instructions);
if (s == visit_stop)
return s;
}
if (s != visit_continue_with_parent) {
s = visit_list_elements(v, &this->else_instructions);
if (s == visit_stop)
return s;
}
return v->visit_leave(this);
}