static void
lower_load_store(nir_builder *b,
nir_intrinsic_instr *intrin,
glsl_type_size_align_func size_align)
{
b->cursor = nir_before_instr(&intrin->instr);
nir_deref_instr *deref = nir_src_as_deref(intrin->src[0]);
nir_variable *var = nir_deref_instr_get_variable(deref);
nir_ssa_def *offset =
nir_iadd_imm(b, nir_build_deref_offset(b, deref, size_align),
var->data.location);
unsigned align, UNUSED size;
size_align(deref->type, &size, &align);
if (intrin->intrinsic == nir_intrinsic_load_deref) {
nir_intrinsic_instr *load =
nir_intrinsic_instr_create(b->shader, nir_intrinsic_load_scratch);
load->num_components = intrin->num_components;
load->src[0] = nir_src_for_ssa(offset);
nir_intrinsic_set_align(load, align, 0);
nir_ssa_dest_init(&load->instr, &load->dest,
intrin->dest.ssa.num_components,
intrin->dest.ssa.bit_size, NULL);
nir_builder_instr_insert(b, &load->instr);
nir_ssa_def *value = &load->dest.ssa;
if (glsl_type_is_boolean(deref->type))
value = nir_b2i32(b, value);
nir_ssa_def_rewrite_uses(&intrin->dest.ssa,
nir_src_for_ssa(&load->dest.ssa));
} else {
assert(intrin->intrinsic == nir_intrinsic_store_deref);
assert(intrin->src[1].is_ssa);
nir_ssa_def *value = intrin->src[1].ssa;
if (glsl_type_is_boolean(deref->type))
value = nir_i2b(b, value);
nir_intrinsic_instr *store =
nir_intrinsic_instr_create(b->shader, nir_intrinsic_store_scratch);
store->num_components = intrin->num_components;
store->src[0] = nir_src_for_ssa(value);
store->src[1] = nir_src_for_ssa(offset);
nir_intrinsic_set_write_mask(store, nir_intrinsic_write_mask(intrin));
nir_intrinsic_set_align(store, align, 0);
nir_builder_instr_insert(b, &store->instr);
}
nir_instr_remove(&intrin->instr);
nir_deref_instr_remove_if_unused(deref);
}
/**
* Try to mark a portion of the given varying as used. Caller must ensure
* that the variable represents a shader input or output.
*
* If the index can't be interpreted as a constant, or some other problem
* occurs, then nothing will be marked and false will be returned.
*/
static bool
try_mask_partial_io(nir_shader *shader, nir_variable *var,
nir_deref_instr *deref, bool is_output_read)
{
const struct glsl_type *type = var->type;
if (nir_is_per_vertex_io(var, shader->info.stage)) {
assert(glsl_type_is_array(type));
type = glsl_get_array_element(type);
}
/* The code below only handles:
*
* - Indexing into matrices
* - Indexing into arrays of (arrays, matrices, vectors, or scalars)
*
* For now, we just give up if we see varying structs and arrays of structs
* here marking the entire variable as used.
*/
if (!(glsl_type_is_matrix(type) ||
(glsl_type_is_array(type) && !var->data.compact &&
(glsl_type_is_numeric(glsl_without_array(type)) ||
glsl_type_is_boolean(glsl_without_array(type)))))) {
/* If we don't know how to handle this case, give up and let the
* caller mark the whole variable as used.
*/
return false;
}
unsigned offset = get_io_offset(deref, false);
if (offset == -1)
return false;
unsigned num_elems;
unsigned elem_width = 1;
unsigned mat_cols = 1;
if (glsl_type_is_array(type)) {
num_elems = glsl_get_aoa_size(type);
if (glsl_type_is_matrix(glsl_without_array(type)))
mat_cols = glsl_get_matrix_columns(glsl_without_array(type));
} else {
num_elems = glsl_get_matrix_columns(type);
}
/* double element width for double types that takes two slots */
if (glsl_type_is_dual_slot(glsl_without_array(type)))
elem_width *= 2;
if (offset >= num_elems * elem_width * mat_cols) {
/* Constant index outside the bounds of the matrix/array. This could
* arise as a result of constant folding of a legal GLSL program.
*
* Even though the spec says that indexing outside the bounds of a
* matrix/array results in undefined behaviour, we don't want to pass
* out-of-range values to set_io_mask() (since this could result in
* slots that don't exist being marked as used), so just let the caller
* mark the whole variable as used.
*/
return false;
}
set_io_mask(shader, var, offset, elem_width, is_output_read);
return true;
}
