nir_deref_var *
vtn_access_chain_to_deref(struct vtn_builder *b, struct vtn_access_chain *chain)
{
nir_deref_var *deref_var;
if (chain->var->var) {
deref_var = nir_deref_var_create(b, chain->var->var);
} else {
assert(chain->var->members);
/* Create the deref_var manually. It will get filled out later. */
deref_var = rzalloc(b, nir_deref_var);
deref_var->deref.deref_type = nir_deref_type_var;
}
struct vtn_type *deref_type = chain->var->type;
nir_deref *tail = &deref_var->deref;
nir_variable **members = chain->var->members;
for (unsigned i = 0; i < chain->length; i++) {
enum glsl_base_type base_type = glsl_get_base_type(deref_type->type);
switch (base_type) {
case GLSL_TYPE_UINT:
case GLSL_TYPE_INT:
case GLSL_TYPE_FLOAT:
case GLSL_TYPE_DOUBLE:
case GLSL_TYPE_BOOL:
case GLSL_TYPE_ARRAY: {
deref_type = deref_type->array_element;
nir_deref_array *deref_arr = nir_deref_array_create(b);
deref_arr->deref.type = deref_type->type;
if (chain->link[i].mode == vtn_access_mode_literal) {
deref_arr->deref_array_type = nir_deref_array_type_direct;
deref_arr->base_offset = chain->link[i].id;
} else {
assert(chain->link[i].mode == vtn_access_mode_id);
deref_arr->deref_array_type = nir_deref_array_type_indirect;
deref_arr->base_offset = 0;
deref_arr->indirect =
nir_src_for_ssa(vtn_ssa_value(b, chain->link[i].id)->def);
}
tail->child = &deref_arr->deref;
tail = tail->child;
break;
}
case GLSL_TYPE_STRUCT: {
assert(chain->link[i].mode == vtn_access_mode_literal);
unsigned idx = chain->link[i].id;
deref_type = deref_type->members[idx];
if (members) {
/* This is a pre-split structure. */
deref_var->var = members[idx];
rewrite_deref_types(&deref_var->deref, members[idx]->type);
assert(tail->type == deref_type->type);
members = NULL;
} else {
nir_deref_struct *deref_struct = nir_deref_struct_create(b, idx);
deref_struct->deref.type = deref_type->type;
tail->child = &deref_struct->deref;
tail = tail->child;
}
break;
}
default:
unreachable("Invalid type for deref");
}
}
assert(members == NULL);
return deref_var;
}
/* Recursively constructs deref chains to split a copy instruction into
* multiple (if needed) copy instructions with full-length deref chains.
* External callers of this function should pass the tail and head of the
* deref chains found as the source and destination of the copy instruction
* into this function.
*
* \param old_copy The copy instruction we are splitting
* \param dest_head The head of the destination deref chain we are building
* \param src_head The head of the source deref chain we are building
* \param dest_tail The tail of the destination deref chain we are building
* \param src_tail The tail of the source deref chain we are building
* \param state The current split_var_copies_state object
*/
static void
split_var_copy_instr(nir_intrinsic_instr *old_copy,
nir_deref *dest_head, nir_deref *src_head,
nir_deref *dest_tail, nir_deref *src_tail,
struct split_var_copies_state *state)
{
assert(src_tail->type == dest_tail->type);
/* Make sure these really are the tails of the deref chains */
assert(dest_tail->child == NULL);
assert(src_tail->child == NULL);
switch (glsl_get_base_type(src_tail->type)) {
case GLSL_TYPE_ARRAY: {
/* Make a wildcard dereference */
nir_deref_array *deref = nir_deref_array_create(state->dead_ctx);
deref->deref.type = glsl_get_array_element(src_tail->type);
deref->deref_array_type = nir_deref_array_type_wildcard;
/* Set the tail of both as the newly created wildcard deref. It is
* safe to use the same wildcard in both places because a) we will be
* copying it before we put it in an actual instruction and b)
* everything that will potentially add another link in the deref
* chain will also add the same thing to both chains.
*/
src_tail->child = &deref->deref;
dest_tail->child = &deref->deref;
split_var_copy_instr(old_copy, dest_head, src_head,
dest_tail->child, src_tail->child, state);
/* Set it back to the way we found it */
src_tail->child = NULL;
dest_tail->child = NULL;
break;
}
case GLSL_TYPE_STRUCT:
/* This is the only part that actually does any interesting
* splitting. For array types, we just use wildcards and resolve
* them later. For structure types, we need to emit one copy
* instruction for every structure element. Because we may have
* structs inside structs, we just recurse and let the next level
* take care of any additional structures.
*/
for (unsigned i = 0; i < glsl_get_length(src_tail->type); i++) {
nir_deref_struct *deref = nir_deref_struct_create(state->dead_ctx, i);
deref->deref.type = glsl_get_struct_field(src_tail->type, i);
/* Set the tail of both as the newly created structure deref. It
* is safe to use the same wildcard in both places because a) we
* will be copying it before we put it in an actual instruction
* and b) everything that will potentially add another link in the
* deref chain will also add the same thing to both chains.
*/
src_tail->child = &deref->deref;
dest_tail->child = &deref->deref;
split_var_copy_instr(old_copy, dest_head, src_head,
dest_tail->child, src_tail->child, state);
}
/* Set it back to the way we found it */
src_tail->child = NULL;
dest_tail->child = NULL;
break;
case GLSL_TYPE_UINT:
case GLSL_TYPE_INT:
case GLSL_TYPE_FLOAT:
case GLSL_TYPE_BOOL:
if (glsl_type_is_matrix(src_tail->type)) {
nir_deref_array *deref = nir_deref_array_create(state->dead_ctx);
deref->deref.type = glsl_get_column_type(src_tail->type);
deref->deref_array_type = nir_deref_array_type_wildcard;
/* Set the tail of both as the newly created wildcard deref. It
* is safe to use the same wildcard in both places because a) we
* will be copying it before we put it in an actual instruction
* and b) everything that will potentially add another link in the
* deref chain will also add the same thing to both chains.
*/
src_tail->child = &deref->deref;
dest_tail->child = &deref->deref;
split_var_copy_instr(old_copy, dest_head, src_head,
dest_tail->child, src_tail->child, state);
/* Set it back to the way we found it */
src_tail->child = NULL;
dest_tail->child = NULL;
} else {
/* At this point, we have fully built our deref chains and can
* actually add the new copy instruction.
*/
nir_intrinsic_instr *new_copy =
nir_intrinsic_instr_create(state->mem_ctx, nir_intrinsic_copy_var);
/* We need to make copies because a) this deref chain actually
* belongs to the copy instruction and b) the deref chains may
* have some of the same links due to the way we constructed them
*/
nir_deref *src = nir_copy_deref(new_copy, src_head);
nir_deref *dest = nir_copy_deref(new_copy, dest_head);
new_copy->variables[0] = nir_deref_as_var(dest);
new_copy->variables[1] = nir_deref_as_var(src);
/* Emit the copy instruction after the old instruction. We'll
* remove the old one later.
*/
nir_instr_insert_after(&old_copy->instr, &new_copy->instr);
state->progress = true;
}
break;
case GLSL_TYPE_SAMPLER:
case GLSL_TYPE_IMAGE:
case GLSL_TYPE_ATOMIC_UINT:
case GLSL_TYPE_INTERFACE:
default:
unreachable("Cannot copy these types");
}
}
static void
_vtn_local_load_store(struct vtn_builder *b, bool load, nir_deref_var *deref,
nir_deref *tail, struct vtn_ssa_value *inout)
{
/* The deref tail may contain a deref to select a component of a vector (in
* other words, it might not be an actual tail) so we have to save it away
* here since we overwrite it later.
*/
nir_deref *old_child = tail->child;
if (glsl_type_is_vector_or_scalar(tail->type)) {
/* Terminate the deref chain in case there is one more link to pick
* off a component of the vector.
*/
tail->child = NULL;
nir_intrinsic_op op = load ? nir_intrinsic_load_var :
nir_intrinsic_store_var;
nir_intrinsic_instr *intrin = nir_intrinsic_instr_create(b->shader, op);
intrin->variables[0] =
nir_deref_as_var(nir_copy_deref(intrin, &deref->deref));
intrin->num_components = glsl_get_vector_elements(tail->type);
if (load) {
nir_ssa_dest_init(&intrin->instr, &intrin->dest,
intrin->num_components,
glsl_get_bit_size(glsl_get_base_type(tail->type)),
NULL);
inout->def = &intrin->dest.ssa;
} else {
nir_intrinsic_set_write_mask(intrin, (1 << intrin->num_components) - 1);
intrin->src[0] = nir_src_for_ssa(inout->def);
}
nir_builder_instr_insert(&b->nb, &intrin->instr);
} else if (glsl_get_base_type(tail->type) == GLSL_TYPE_ARRAY ||
glsl_type_is_matrix(tail->type)) {
unsigned elems = glsl_get_length(tail->type);
nir_deref_array *deref_arr = nir_deref_array_create(b);
deref_arr->deref_array_type = nir_deref_array_type_direct;
deref_arr->deref.type = glsl_get_array_element(tail->type);
tail->child = &deref_arr->deref;
for (unsigned i = 0; i < elems; i++) {
deref_arr->base_offset = i;
_vtn_local_load_store(b, load, deref, tail->child, inout->elems[i]);
}
} else {
assert(glsl_get_base_type(tail->type) == GLSL_TYPE_STRUCT);
unsigned elems = glsl_get_length(tail->type);
nir_deref_struct *deref_struct = nir_deref_struct_create(b, 0);
tail->child = &deref_struct->deref;
for (unsigned i = 0; i < elems; i++) {
deref_struct->index = i;
deref_struct->deref.type = glsl_get_struct_field(tail->type, i);
_vtn_local_load_store(b, load, deref, tail->child, inout->elems[i]);
}
}
tail->child = old_child;
}
