static bool
loop_is_dead(nir_loop *loop)
{
nir_block *before = nir_cf_node_as_block(nir_cf_node_prev(&loop->cf_node));
nir_block *after = nir_cf_node_as_block(nir_cf_node_next(&loop->cf_node));
if (!exec_list_is_empty(&after->instr_list) &&
nir_block_first_instr(after)->type == nir_instr_type_phi)
return false;
if (!nir_foreach_block_in_cf_node(&loop->cf_node, block_has_no_side_effects,
NULL))
return false;
nir_function_impl *impl = nir_cf_node_get_function(&loop->cf_node);
nir_metadata_require(impl, nir_metadata_live_variables |
nir_metadata_dominance);
for (nir_block *cur = after->imm_dom; cur != before; cur = cur->imm_dom) {
nir_foreach_instr(cur, instr) {
if (!nir_foreach_ssa_def(instr, def_not_live_out, after))
return false;
}
}
return true;
}
static bool
constant_fold_intrinsic_instr(nir_intrinsic_instr *instr)
{
bool progress = false;
if (instr->intrinsic == nir_intrinsic_discard_if &&
nir_src_is_const(instr->src[0])) {
if (nir_src_as_bool(instr->src[0])) {
/* This method of getting a nir_shader * from a nir_instr is
* admittedly gross, but given the rarity of hitting this case I think
* it's preferable to plumbing an otherwise unused nir_shader *
* parameter through four functions to get here.
*/
nir_cf_node *cf_node = &instr->instr.block->cf_node;
nir_function_impl *impl = nir_cf_node_get_function(cf_node);
nir_shader *shader = impl->function->shader;
nir_intrinsic_instr *discard =
nir_intrinsic_instr_create(shader, nir_intrinsic_discard);
nir_instr_insert_before(&instr->instr, &discard->instr);
nir_instr_remove(&instr->instr);
progress = true;
} else {
/* We're not discarding, just delete the instruction */
nir_instr_remove(&instr->instr);
progress = true;
}
}
return progress;
}
static void
lower_load_const_instr_scalar(nir_load_const_instr *lower)
{
if (lower->def.num_components == 1)
return;
nir_builder b;
nir_builder_init(&b, nir_cf_node_get_function(&lower->instr.block->cf_node));
b.cursor = nir_before_instr(&lower->instr);
/* Emit the individual loads. */
nir_ssa_def *loads[4];
for (unsigned i = 0; i < lower->def.num_components; i++) {
nir_load_const_instr *load_comp = nir_load_const_instr_create(b.shader, 1);
load_comp->value.u[0] = lower->value.u[i];
nir_builder_instr_insert(&b, &load_comp->instr);
loads[i] = &load_comp->def;
}
/* Batch things back together into a vector. */
nir_ssa_def *vec = nir_vec(&b, loads, lower->def.num_components);
/* Replace the old load with a reference to our reconstructed vector. */
nir_ssa_def_rewrite_uses(&lower->def, nir_src_for_ssa(vec));
nir_instr_remove(&lower->instr);
}
static bool
vc4_nir_lower_txf_ms_block(nir_block *block, void *arg)
{
struct vc4_compile *c = arg;
nir_function_impl *impl =
nir_cf_node_get_function(&block->cf_node);
nir_builder b;
nir_builder_init(&b, impl);
nir_foreach_instr_safe(block, instr) {
if (instr->type == nir_instr_type_tex) {
vc4_nir_lower_txf_ms_instr(c, &b,
nir_instr_as_tex(instr));
}
}
return true;
}
