/*
* Copyright © 2015 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 "nir.h"
#include "nir_builder.h"
#include "nir_control_flow.h"
static bool inline_function_impl(nir_function_impl *impl, struct set *inlined);
static void
convert_deref_to_param_deref(nir_instr *instr, nir_deref_var **deref,
nir_call_instr *call)
{
/* This isn't a parameter, just return the deref */
if ((*deref)->var->data.mode != nir_var_param)
return;
int param_idx = (*deref)->var->data.location;
nir_deref_var *call_deref;
if (param_idx >= 0) {
assert(param_idx < call->callee->num_params);
call_deref = call->params[param_idx];
} else {
call_deref = call->return_deref;
}
assert(call_deref);
/* Now we make a new deref by concatenating the deref in the call's
* parameter with the deref we were given.
*/
nir_deref_var *new_deref = nir_deref_var_clone(call_deref, instr);
nir_deref *new_tail = nir_deref_tail(&new_deref->deref);
new_tail->child = (*deref)->deref.child;
ralloc_steal(new_tail, new_tail->child);
*deref = new_deref;
}
static void
rewrite_param_derefs(nir_instr *instr, nir_call_instr *call)
{
switch (instr->type) {
case nir_instr_type_intrinsic: {
nir_intrinsic_instr *intrin = nir_instr_as_intrinsic(instr);
for (unsigned i = 0;
i < nir_intrinsic_infos[intrin->intrinsic].num_variables; i++) {
convert_deref_to_param_deref(instr, &intrin->variables[i], call);
}
break;
}
case nir_instr_type_tex: {
nir_tex_instr *tex = nir_instr_as_tex(instr);
if (tex->texture)
convert_deref_to_param_deref(&tex->instr, &tex->texture, call);
if (tex->sampler)
convert_deref_to_param_deref(&tex->instr, &tex->sampler, call);
break;
}
default:
break; /* Nothing else has derefs */
}
}
static void
lower_param_to_local(nir_variable *param, nir_function_impl *impl, bool write)
{
if (param->data.mode != nir_var_param)
return;
nir_parameter_type param_type;
if (param->data.location >= 0) {
assert(param->data.location < impl->num_params);
param_type = impl->function->params[param->data.location].param_type;
} else {
/* Return variable */
param_type = nir_parameter_out;
}
if ((write && param_type == nir_parameter_in) ||
(!write && param_type == nir_parameter_out)) {
/* In this case, we need a shadow copy. Turn it into a local */
param->data.mode = nir_var_local;
exec_list_push_tail(&impl->locals, ¶m->node);
}
}
static bool
lower_params_to_locals_block(nir_block *block, nir_function_impl *impl)
{
nir_foreach_instr(instr, block) {
if (instr->type != nir_instr_type_intrinsic)
continue;
nir_intrinsic_instr *intrin = nir_instr_as_intrinsic(instr);
switch (intrin->intrinsic) {
case nir_intrinsic_store_var:
lower_param_to_local(intrin->variables[0]->var, impl, true);
break;
case nir_intrinsic_copy_var:
lower_param_to_local(intrin->variables[0]->var, impl, true);
lower_param_to_local(intrin->variables[1]->var, impl, false);
break;
case nir_intrinsic_load_var:
/* All other intrinsics which access variables (image_load_store)
* do so in a read-only fasion.
*/
for (unsigned i = 0;
i < nir_intrinsic_infos[intrin->intrinsic].num_variables; i++) {
lower_param_to_local(intrin->variables[i]->var, impl, false);
}
break;
default:
continue;
}
}
return true;
}
static bool
inline_functions_block(nir_block *block, nir_builder *b,
struct set *inlined)
{
bool progress = false;
/* This is tricky. We're iterating over instructions in a block but, as
* we go, the block and its instruction list are being split into
* pieces. However, this *should* be safe since foreach_safe always
* stashes the next thing in the iteration. That next thing will
* properly get moved to the next block when it gets split, and we
* continue iterating there.
*/
nir_foreach_instr_safe(instr, block) {
if (instr->type != nir_instr_type_call)
continue;
progress = true;
nir_call_instr *call = nir_instr_as_call(instr);
assert(call->callee->impl);
inline_function_impl(call->callee->impl, inlined);
nir_function_impl *callee_copy =
nir_function_impl_clone(call->callee->impl);
callee_copy->function = call->callee;
/* Add copies of all in parameters */
assert(call->num_params == callee_copy->num_params);
exec_list_append(&b->impl->locals, &callee_copy->locals);
exec_list_append(&b->impl->registers, &callee_copy->registers);
b->cursor = nir_before_instr(&call->instr);
/* We now need to tie the two functions together using the
* parameters. There are two ways we do this: One is to turn the
* parameter into a local variable and do a shadow-copy. The other
* is to treat the parameter as a "proxy" and rewrite derefs to use
* the actual variable that comes from the call instruction. We
* implement both schemes. The first is needed in the case where we
* have an in parameter that we write or similar. The second case is
* needed for handling things such as images and uniforms properly.
*/
/* Figure out when we need to lower to a shadow local */
nir_foreach_block(block, callee_copy) {
lower_params_to_locals_block(block, callee_copy);
}
for (unsigned i = 0; i < callee_copy->num_params; i++) {
nir_variable *param = callee_copy->params[i];
if (param->data.mode == nir_var_local &&
call->callee->params[i].param_type != nir_parameter_out) {
nir_copy_deref_var(b, nir_deref_var_create(b->shader, param),
call->params[i]);
}
}
nir_foreach_block(block, callee_copy) {
nir_foreach_instr(instr, block)
rewrite_param_derefs(instr, call);
}
/* Pluck the body out of the function and place it here */
nir_cf_list body;
nir_cf_list_extract(&body, &callee_copy->body);
nir_cf_reinsert(&body, b->cursor);
b->cursor = nir_before_instr(&call->instr);
/* Add copies of all out parameters and the return */
assert(call->num_params == callee_copy->num_params);
for (unsigned i = 0; i < callee_copy->num_params; i++) {
nir_variable *param = callee_copy->params[i];
if (param->data.mode == nir_var_local &&
call->callee->params[i].param_type != nir_parameter_in) {
nir_copy_deref_var(b, call->params[i],
nir_deref_var_create(b->shader, param));
}
}
if (!glsl_type_is_void(call->callee->return_type) &&
callee_copy->return_var->data.mode == nir_var_local) {
nir_copy_deref_var(b, call->return_deref,
nir_deref_var_create(b->shader,
callee_copy->return_var));
}
nir_instr_remove(&call->instr);
}
return progress;
}
static bool
inline_function_impl(nir_function_impl *impl, struct set *inlined)
{
if (_mesa_set_search(inlined, impl))
return false; /* Already inlined */
nir_builder b;
nir_builder_init(&b, impl);
bool progress = false;
nir_foreach_block_safe(block, impl) {
progress |= inline_functions_block(block, &b, inlined);
}
if (progress) {
/* SSA and register indices are completely messed up now */
nir_index_ssa_defs(impl);
nir_index_local_regs(impl);
nir_metadata_preserve(impl, nir_metadata_none);
}
_mesa_set_add(inlined, impl);
return progress;
}
bool
nir_inline_functions(nir_shader *shader)
{
struct set *inlined = _mesa_set_create(NULL, _mesa_hash_pointer,
_mesa_key_pointer_equal);
bool progress = false;
nir_foreach_function(function, shader) {
if (function->impl)
progress = inline_function_impl(function->impl, inlined) || progress;
}
_mesa_set_destroy(inlined, NULL);
return progress;
}