/*
* 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_function_inlining.cpp
*
* Replaces calls to functions with the body of the function.
*/
#include "ir.h"
#include "ir_visitor.h"
#include "ir_function_inlining.h"
#include "ir_expression_flattening.h"
#include "compiler/glsl_types.h"
#include "util/hash_table.h"
static void
do_variable_replacement(exec_list *instructions,
ir_variable *orig,
ir_dereference *repl);
namespace {
class ir_function_inlining_visitor : public ir_hierarchical_visitor {
public:
ir_function_inlining_visitor()
{
progress = false;
}
virtual ~ir_function_inlining_visitor()
{
/* empty */
}
virtual ir_visitor_status visit_enter(ir_expression *);
virtual ir_visitor_status visit_enter(ir_call *);
virtual ir_visitor_status visit_enter(ir_return *);
virtual ir_visitor_status visit_enter(ir_texture *);
virtual ir_visitor_status visit_enter(ir_swizzle *);
bool progress;
};
class ir_save_lvalue_visitor : public ir_hierarchical_visitor {
public:
virtual ir_visitor_status visit_enter(ir_dereference_array *);
};
} /* unnamed namespace */
bool
do_function_inlining(exec_list *instructions)
{
ir_function_inlining_visitor v;
v.run(instructions);
return v.progress;
}
static void
replace_return_with_assignment(ir_instruction *ir, void *data)
{
void *ctx = ralloc_parent(ir);
ir_dereference *orig_deref = (ir_dereference *) data;
ir_return *ret = ir->as_return();
if (ret) {
if (ret->value) {
ir_rvalue *lhs = orig_deref->clone(ctx, NULL);
ret->replace_with(new(ctx) ir_assignment(lhs, ret->value));
} else {
/* un-valued return has to be the last return, or we shouldn't
* have reached here. (see can_inline()).
*/
assert(ret->next->is_tail_sentinel());
ret->remove();
}
}
}
/* Save the given lvalue before the given instruction.
*
* This is done by adding temporary variables into which the current value
* of any array indices are saved, and then modifying the dereference chain
* in-place to point to those temporary variables.
*
* The hierarchical visitor is only used to traverse the left-hand-side chain
* of derefs.
*/
ir_visitor_status
ir_save_lvalue_visitor::visit_enter(ir_dereference_array *deref)
{
if (deref->array_index->ir_type != ir_type_constant) {
void *ctx = ralloc_parent(deref);
ir_variable *index;
ir_assignment *assignment;
index = new(ctx) ir_variable(deref->array_index->type, "saved_idx", ir_var_temporary);
base_ir->insert_before(index);
assignment = new(ctx) ir_assignment(new(ctx) ir_dereference_variable(index),
deref->array_index);
base_ir->insert_before(assignment);
deref->array_index = new(ctx) ir_dereference_variable(index);
}
deref->array->accept(this);
return visit_stop;
}
void
ir_call::generate_inline(ir_instruction *next_ir)
{
void *ctx = ralloc_parent(this);
ir_variable **parameters;
unsigned num_parameters;
int i;
struct hash_table *ht;
ht = _mesa_hash_table_create(NULL, _mesa_hash_pointer, _mesa_key_pointer_equal);
num_parameters = this->callee->parameters.length();
parameters = new ir_variable *[num_parameters];
/* Generate the declarations for the parameters to our inlined code,
* and set up the mapping of real function body variables to ours.
*/
i = 0;
foreach_two_lists(formal_node, &this->callee->parameters,
actual_node, &this->actual_parameters) {
ir_variable *sig_param = (ir_variable *) formal_node;
ir_rvalue *param = (ir_rvalue *) actual_node;
/* Generate a new variable for the parameter. */
if (sig_param->type->contains_opaque()) {
/* For opaque types, we want the inlined variable references
* referencing the passed in variable, since that will have
* the location information, which an assignment of an opaque
* variable wouldn't. Fix it up below.
*/
parameters[i] = NULL;
} else {
parameters[i] = sig_param->clone(ctx, ht);
parameters[i]->data.mode = ir_var_temporary;
/* Remove the read-only decoration because we're going to write
* directly to this variable. If the cloned variable is left
* read-only and the inlined function is inside a loop, the loop
* analysis code will get confused.
*/
parameters[i]->data.read_only = false;
next_ir->insert_before(parameters[i]);
}
/* Section 6.1.1 (Function Calling Conventions) of the OpenGL Shading
* Language 4.5 spec says:
*
* "All arguments are evaluated at call time, exactly once, in order,
* from left to right. [...] Evaluation of an out parameter results
* in an l-value that is used to copy out a value when the function
* returns."
*
* I.e., we have to take temporary copies of any relevant array indices
* before the function body is executed.
*
* This ensures that
* (a) if an array index expressions refers to a variable that is
* modified by the execution of the function body, we use the
* original value as intended, and
* (b) if an array index expression has side effects, those side effects
* are only executed once and at the right time.
*/
if (parameters[i]) {
if (sig_param->data.mode == ir_var_function_in ||
sig_param->data.mode == ir_var_const_in) {
ir_assignment *assign;
assign = new(ctx) ir_assignment(new(ctx) ir_dereference_variable(parameters[i]),
param);
next_ir->insert_before(assign);
} else {
assert(sig_param->data.mode == ir_var_function_out ||
sig_param->data.mode == ir_var_function_inout);
assert(param->is_lvalue());
ir_save_lvalue_visitor v;
v.base_ir = next_ir;
param->accept(&v);
if (sig_param->data.mode == ir_var_function_inout) {
ir_assignment *assign;
assign = new(ctx) ir_assignment(new(ctx) ir_dereference_variable(parameters[i]),
param->clone(ctx, NULL)->as_rvalue());
next_ir->insert_before(assign);
}
}
}
++i;
}
exec_list new_instructions;
/* Generate the inlined body of the function to a new list */
foreach_in_list(ir_instruction, ir, &callee->body) {
ir_instruction *new_ir = ir->clone(ctx, ht);
new_instructions.push_tail(new_ir);
visit_tree(new_ir, replace_return_with_assignment, this->return_deref);
}
/* If any opaque types were passed in, replace any deref of the
* opaque variable with a deref of the argument.
*/
foreach_two_lists(formal_node, &this->callee->parameters,
actual_node, &this->actual_parameters) {
ir_rvalue *const param = (ir_rvalue *) actual_node;
ir_variable *sig_param = (ir_variable *) formal_node;
if (sig_param->type->contains_opaque()) {
ir_dereference *deref = param->as_dereference();
assert(deref);
do_variable_replacement(&new_instructions, sig_param, deref);
}
}
/* Now push those new instructions in. */
next_ir->insert_before(&new_instructions);
/* Copy back the value of any 'out' parameters from the function body
* variables to our own.
*/
i = 0;
foreach_two_lists(formal_node, &this->callee->parameters,
actual_node, &this->actual_parameters) {
ir_rvalue *const param = (ir_rvalue *) actual_node;
const ir_variable *const sig_param = (ir_variable *) formal_node;
/* Move our param variable into the actual param if it's an 'out' type. */
if (parameters[i] && (sig_param->data.mode == ir_var_function_out ||
sig_param->data.mode == ir_var_function_inout)) {
ir_assignment *assign;
assign = new(ctx) ir_assignment(param,
new(ctx) ir_dereference_variable(parameters[i]));
next_ir->insert_before(assign);
}
++i;
}
delete [] parameters;
_mesa_hash_table_destroy(ht, NULL);
}
ir_visitor_status
ir_function_inlining_visitor::visit_enter(ir_expression *ir)
{
(void) ir;
return visit_continue_with_parent;
}
ir_visitor_status
ir_function_inlining_visitor::visit_enter(ir_return *ir)
{
(void) ir;
return visit_continue_with_parent;
}
ir_visitor_status
ir_function_inlining_visitor::visit_enter(ir_texture *ir)
{
(void) ir;
return visit_continue_with_parent;
}
ir_visitor_status
ir_function_inlining_visitor::visit_enter(ir_swizzle *ir)
{
(void) ir;
return visit_continue_with_parent;
}
ir_visitor_status
ir_function_inlining_visitor::visit_enter(ir_call *ir)
{
if (can_inline(ir)) {
ir->generate_inline(ir);
ir->remove();
this->progress = true;
}
return visit_continue;
}
/**
* Replaces references to the "orig" variable with a clone of "repl."
*
* From the spec, opaque types can appear in the tree as function
* (non-out) parameters and as the result of array indexing and
* structure field selection. In our builtin implementation, they
* also appear in the sampler field of an ir_tex instruction.
*/
class ir_variable_replacement_visitor : public ir_hierarchical_visitor {
public:
ir_variable_replacement_visitor(ir_variable *orig, ir_dereference *repl)
{
this->orig = orig;
this->repl = repl;
}
virtual ~ir_variable_replacement_visitor()
{
}
virtual ir_visitor_status visit_leave(ir_call *);
virtual ir_visitor_status visit_leave(ir_dereference_array *);
virtual ir_visitor_status visit_leave(ir_dereference_record *);
virtual ir_visitor_status visit_leave(ir_texture *);
void replace_deref(ir_dereference **deref);
void replace_rvalue(ir_rvalue **rvalue);
ir_variable *orig;
ir_dereference *repl;
};
void
ir_variable_replacement_visitor::replace_deref(ir_dereference **deref)
{
ir_dereference_variable *deref_var = (*deref)->as_dereference_variable();
if (deref_var && deref_var->var == this->orig) {
*deref = this->repl->clone(ralloc_parent(*deref), NULL);
}
}
void
ir_variable_replacement_visitor::replace_rvalue(ir_rvalue **rvalue)
{
if (!*rvalue)
return;
ir_dereference *deref = (*rvalue)->as_dereference();
if (!deref)
return;
replace_deref(&deref);
*rvalue = deref;
}
ir_visitor_status
ir_variable_replacement_visitor::visit_leave(ir_texture *ir)
{
replace_deref(&ir->sampler);
return visit_continue;
}
ir_visitor_status
ir_variable_replacement_visitor::visit_leave(ir_dereference_array *ir)
{
replace_rvalue(&ir->array);
return visit_continue;
}
ir_visitor_status
ir_variable_replacement_visitor::visit_leave(ir_dereference_record *ir)
{
replace_rvalue(&ir->record);
return visit_continue;
}
ir_visitor_status
ir_variable_replacement_visitor::visit_leave(ir_call *ir)
{
foreach_in_list_safe(ir_rvalue, param, &ir->actual_parameters) {
ir_rvalue *new_param = param;
replace_rvalue(&new_param);
if (new_param != param) {
param->replace_with(new_param);
}
}
return visit_continue;
}
static void
do_variable_replacement(exec_list *instructions,
ir_variable *orig,
ir_dereference *repl)
{
ir_variable_replacement_visitor v(orig, repl);
visit_list_elements(&v, instructions);
}