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android / platform / external / mesa3d / bbedfb41834 / . / src / compiler / nir / nir_opt_copy_prop_vars.c
blob: 823bc763c68eb815d0674dd7af132463719b02ee [file] [log] [blame]
/*
* Copyright © 2016 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_deref.h"
#include "util/bitscan.h"
#include "util/u_dynarray.h"
static const bool debug = false;
/**
* Variable-based copy propagation
*
* Normally, NIR trusts in SSA form for most of its copy-propagation needs.
* However, there are cases, especially when dealing with indirects, where SSA
* won't help you. This pass is for those times. Specifically, it handles
* the following things that the rest of NIR can't:
*
* 1) Copy-propagation on variables that have indirect access. This includes
* propagating from indirect stores into indirect loads.
*
* 2) Removal of redundant load_deref intrinsics. We can't trust regular CSE
* to do this because it isn't aware of variable writes that may alias the
* value and make the former load invalid.
*
* This pass uses an intermediate solution between being local / "per-block"
* and a complete data-flow analysis. It follows the control flow graph, and
* propagate the available copy information forward, invalidating data at each
* cf_node.
*
* Removal of dead writes to variables is handled by another pass.
*/
struct vars_written {
nir_variable_mode modes;
/* Key is deref and value is the uintptr_t with the write mask. */
struct hash_table *derefs;
};
struct value {
bool is_ssa;
union {
struct {
nir_ssa_def *def[NIR_MAX_VEC_COMPONENTS];
uint8_t component[NIR_MAX_VEC_COMPONENTS];
} ssa;
nir_deref_instr *deref;
};
};
static void
value_set_ssa_components(struct value *value, nir_ssa_def *def,
unsigned num_components)
{
if (!value->is_ssa)
memset(&value->ssa, 0, sizeof(value->ssa));
value->is_ssa = true;
for (unsigned i = 0; i < num_components; i++) {
value->ssa.def[i] = def;
value->ssa.component[i] = i;
}
}
struct copy_entry {
struct value src;
nir_deref_instr *dst;
};
struct copy_prop_var_state {
nir_function_impl *impl;
void *mem_ctx;
void *lin_ctx;
/* Maps nodes to vars_written. Used to invalidate copy entries when
* visiting each node.
*/
struct hash_table *vars_written_map;
bool progress;
};
static bool
value_equals_store_src(struct value *value, nir_intrinsic_instr *intrin)
{
assert(intrin->intrinsic == nir_intrinsic_store_deref);
uintptr_t write_mask = nir_intrinsic_write_mask(intrin);
for (unsigned i = 0; i < intrin->num_components; i++) {
if ((write_mask & (1 << i)) &&
(value->ssa.def[i] != intrin->src[1].ssa ||
value->ssa.component[i] != i))
return false;
}
return true;
}
static struct vars_written *
create_vars_written(struct copy_prop_var_state *state)
{
struct vars_written *written =
linear_zalloc_child(state->lin_ctx, sizeof(struct vars_written));
written->derefs = _mesa_pointer_hash_table_create(state->mem_ctx);
return written;
}
static void
gather_vars_written(struct copy_prop_var_state *state,
struct vars_written *written,
nir_cf_node *cf_node)
{
struct vars_written *new_written = NULL;
switch (cf_node->type) {
case nir_cf_node_function: {
nir_function_impl *impl = nir_cf_node_as_function(cf_node);
foreach_list_typed_safe(nir_cf_node, cf_node, node, &impl->body)
gather_vars_written(state, NULL, cf_node);
break;
}
case nir_cf_node_block: {
if (!written)
break;
nir_block *block = nir_cf_node_as_block(cf_node);
nir_foreach_instr(instr, block) {
if (instr->type == nir_instr_type_call) {
written->modes |= nir_var_shader_out |
nir_var_shader_temp |
nir_var_function_temp |
nir_var_mem_ssbo |
nir_var_mem_shared |
nir_var_mem_global;
continue;
}
if (instr->type != nir_instr_type_intrinsic)
continue;
nir_intrinsic_instr *intrin = nir_instr_as_intrinsic(instr);
switch (intrin->intrinsic) {
case nir_intrinsic_control_barrier:
case nir_intrinsic_group_memory_barrier:
case nir_intrinsic_memory_barrier:
written->modes |= nir_var_shader_out |
nir_var_mem_ssbo |
nir_var_mem_shared |
nir_var_mem_global;
break;
case nir_intrinsic_scoped_barrier:
if (nir_intrinsic_memory_semantics(intrin) & NIR_MEMORY_ACQUIRE)
written->modes |= nir_intrinsic_memory_modes(intrin);
break;
case nir_intrinsic_emit_vertex:
case nir_intrinsic_emit_vertex_with_counter:
written->modes = nir_var_shader_out;
break;
case nir_intrinsic_trace_ray:
case nir_intrinsic_execute_callable: {
nir_deref_instr *payload =
nir_src_as_deref(*nir_get_shader_call_payload_src(intrin));
nir_component_mask_t mask =
(nir_component_mask_t) BITFIELD_MASK(glsl_get_vector_elements(payload->type));
struct hash_entry *ht_entry =
_mesa_hash_table_search(written->derefs, payload);
if (ht_entry) {
ht_entry->data = (void *)(mask | (uintptr_t)ht_entry->data);
} else {
_mesa_hash_table_insert(written->derefs, payload,
(void *)(uintptr_t)mask);
}
break;
}
case nir_intrinsic_report_ray_intersection:
written->modes |= nir_var_mem_ssbo |
nir_var_mem_global |
nir_var_shader_call_data |
nir_var_ray_hit_attrib;
break;
case nir_intrinsic_ignore_ray_intersection:
case nir_intrinsic_terminate_ray:
written->modes |= nir_var_mem_ssbo |
nir_var_mem_global |
nir_var_shader_call_data;
break;
case nir_intrinsic_deref_atomic_add:
case nir_intrinsic_deref_atomic_fadd:
case nir_intrinsic_deref_atomic_imin:
case nir_intrinsic_deref_atomic_umin:
case nir_intrinsic_deref_atomic_fmin:
case nir_intrinsic_deref_atomic_imax:
case nir_intrinsic_deref_atomic_umax:
case nir_intrinsic_deref_atomic_fmax:
case nir_intrinsic_deref_atomic_and:
case nir_intrinsic_deref_atomic_or:
case nir_intrinsic_deref_atomic_xor:
case nir_intrinsic_deref_atomic_exchange:
case nir_intrinsic_deref_atomic_comp_swap:
case nir_intrinsic_deref_atomic_fcomp_swap:
case nir_intrinsic_store_deref:
case nir_intrinsic_copy_deref:
case nir_intrinsic_memcpy_deref: {
/* Destination in all of store_deref, copy_deref and the atomics is src[0]. */
nir_deref_instr *dst = nir_src_as_deref(intrin->src[0]);
uintptr_t mask = intrin->intrinsic == nir_intrinsic_store_deref ?
nir_intrinsic_write_mask(intrin) : (1 << glsl_get_vector_elements(dst->type)) - 1;
struct hash_entry *ht_entry = _mesa_hash_table_search(written->derefs, dst);
if (ht_entry)
ht_entry->data = (void *)(mask | (uintptr_t)ht_entry->data);
else
_mesa_hash_table_insert(written->derefs, dst, (void *)mask);
break;
}
default:
break;
}
}
break;
}
case nir_cf_node_if: {
nir_if *if_stmt = nir_cf_node_as_if(cf_node);
new_written = create_vars_written(state);
foreach_list_typed_safe(nir_cf_node, cf_node, node, &if_stmt->then_list)
gather_vars_written(state, new_written, cf_node);
foreach_list_typed_safe(nir_cf_node, cf_node, node, &if_stmt->else_list)
gather_vars_written(state, new_written, cf_node);
break;
}
case nir_cf_node_loop: {
nir_loop *loop = nir_cf_node_as_loop(cf_node);
new_written = create_vars_written(state);
foreach_list_typed_safe(nir_cf_node, cf_node, node, &loop->body)
gather_vars_written(state, new_written, cf_node);
break;
}
default:
unreachable("Invalid CF node type");
}
if (new_written) {
/* Merge new information to the parent control flow node. */
if (written) {
written->modes |= new_written->modes;
hash_table_foreach(new_written->derefs, new_entry) {
struct hash_entry *old_entry =
_mesa_hash_table_search_pre_hashed(written->derefs, new_entry->hash,
new_entry->key);
if (old_entry) {
nir_component_mask_t merged = (uintptr_t) new_entry->data |
(uintptr_t) old_entry->data;
old_entry->data = (void *) ((uintptr_t) merged);
} else {
_mesa_hash_table_insert_pre_hashed(written->derefs, new_entry->hash,
new_entry->key, new_entry->data);
}
}
}
_mesa_hash_table_insert(state->vars_written_map, cf_node, new_written);
}
}
static struct copy_entry *
copy_entry_create(struct util_dynarray *copies,
nir_deref_instr *dst_deref)
{
struct copy_entry new_entry = {
.dst = dst_deref,
};
util_dynarray_append(copies, struct copy_entry, new_entry);
return util_dynarray_top_ptr(copies, struct copy_entry);
}
/* Remove copy entry by swapping it with the last element and reducing the
* size. If used inside an iteration on copies, it must be a reverse
* (backwards) iteration. It is safe to use in those cases because the swap
* will not affect the rest of the iteration.
*/
static void
copy_entry_remove(struct util_dynarray *copies,
struct copy_entry *entry)
{
const struct copy_entry *src =
util_dynarray_pop_ptr(copies, struct copy_entry);
if (src != entry)
*entry = *src;
}
static bool
is_array_deref_of_vector(nir_deref_instr *deref)
{
if (deref->deref_type != nir_deref_type_array)
return false;
nir_deref_instr *parent = nir_deref_instr_parent(deref);
return glsl_type_is_vector(parent->type);
}
static struct copy_entry *
lookup_entry_for_deref(struct util_dynarray *copies,
nir_deref_instr *deref,
nir_deref_compare_result allowed_comparisons)
{
struct copy_entry *entry = NULL;
util_dynarray_foreach(copies, struct copy_entry, iter) {
nir_deref_compare_result result = nir_compare_derefs(iter->dst, deref);
if (result & allowed_comparisons) {
entry = iter;
if (result & nir_derefs_equal_bit)
break;
/* Keep looking in case we have an equal match later in the array. */
}
}
return entry;
}
static struct copy_entry *
lookup_entry_and_kill_aliases(struct util_dynarray *copies,
nir_deref_instr *deref,
unsigned write_mask)
{
/* TODO: Take into account the write_mask. */
nir_deref_instr *dst_match = NULL;
util_dynarray_foreach_reverse(copies, struct copy_entry, iter) {
if (!iter->src.is_ssa) {
/* If this write aliases the source of some entry, get rid of it */
if (nir_compare_derefs(iter->src.deref, deref) & nir_derefs_may_alias_bit) {
copy_entry_remove(copies, iter);
continue;
}
}
nir_deref_compare_result comp = nir_compare_derefs(iter->dst, deref);
if (comp & nir_derefs_equal_bit) {
/* Removing entries invalidate previous iter pointers, so we'll
* collect the matching entry later. Just make sure it is unique.
*/
assert(!dst_match);
dst_match = iter->dst;
} else if (comp & nir_derefs_may_alias_bit) {
copy_entry_remove(copies, iter);
}
}
struct copy_entry *entry = NULL;
if (dst_match) {
util_dynarray_foreach(copies, struct copy_entry, iter) {
if (iter->dst == dst_match) {
entry = iter;
break;
}
}
assert(entry);
}
return entry;
}
static void
kill_aliases(struct util_dynarray *copies,
nir_deref_instr *deref,
unsigned write_mask)
{
/* TODO: Take into account the write_mask. */
struct copy_entry *entry =
lookup_entry_and_kill_aliases(copies, deref, write_mask);
if (entry)
copy_entry_remove(copies, entry);
}
static struct copy_entry *
get_entry_and_kill_aliases(struct util_dynarray *copies,
nir_deref_instr *deref,
unsigned write_mask)
{
/* TODO: Take into account the write_mask. */
struct copy_entry *entry =
lookup_entry_and_kill_aliases(copies, deref, write_mask);
if (entry == NULL)
entry = copy_entry_create(copies, deref);
return entry;
}
static void
apply_barrier_for_modes(struct util_dynarray *copies,
nir_variable_mode modes)
{
util_dynarray_foreach_reverse(copies, struct copy_entry, iter) {
if (nir_deref_mode_may_be(iter->dst, modes) ||
(!iter->src.is_ssa && nir_deref_mode_may_be(iter->src.deref, modes)))
copy_entry_remove(copies, iter);
}
}
static void
value_set_from_value(struct value *value, const struct value *from,
unsigned base_index, unsigned write_mask)
{
/* We can't have non-zero indexes with non-trivial write masks */
assert(base_index == 0 || write_mask == 1);
if (from->is_ssa) {
/* Clear value if it was being used as non-SSA. */
if (!value->is_ssa)
memset(&value->ssa, 0, sizeof(value->ssa));
value->is_ssa = true;
/* Only overwrite the written components */
for (unsigned i = 0; i < NIR_MAX_VEC_COMPONENTS; i++) {
if (write_mask & (1 << i)) {
value->ssa.def[base_index + i] = from->ssa.def[i];
value->ssa.component[base_index + i] = from->ssa.component[i];
}
}
} else {
/* Non-ssa stores always write everything */
value->is_ssa = false;
value->deref = from->deref;
}
}
/* Try to load a single element of a vector from the copy_entry. If the data
* isn't available, just let the original intrinsic do the work.
*/
static bool
load_element_from_ssa_entry_value(struct copy_prop_var_state *state,
struct copy_entry *entry,
nir_builder *b, nir_intrinsic_instr *intrin,
struct value *value, unsigned index)
{
assert(index < glsl_get_vector_elements(entry->dst->type));
/* We don't have the element available, so let the instruction do the work. */
if (!entry->src.ssa.def[index])
return false;
b->cursor = nir_instr_remove(&intrin->instr);
intrin->instr.block = NULL;
assert(entry->src.ssa.component[index] <
entry->src.ssa.def[index]->num_components);
nir_ssa_def *def = nir_channel(b, entry->src.ssa.def[index],
entry->src.ssa.component[index]);
*value = (struct value) {
.is_ssa = true,
{
.ssa = {
.def = { def },
.component = { 0 },
},
}
};
return true;
}
/* Do a "load" from an SSA-based entry return it in "value" as a value with a
* single SSA def. Because an entry could reference multiple different SSA
* defs, a vecN operation may be inserted to combine them into a single SSA
* def before handing it back to the caller. If the load instruction is no
* longer needed, it is removed and nir_instr::block is set to NULL. (It is
* possible, in some cases, for the load to be used in the vecN operation in
* which case it isn't deleted.)
*/
static bool
load_from_ssa_entry_value(struct copy_prop_var_state *state,
struct copy_entry *entry,
nir_builder *b, nir_intrinsic_instr *intrin,
nir_deref_instr *src, struct value *value)
{
if (is_array_deref_of_vector(src)) {
if (nir_src_is_const(src->arr.index)) {
return load_element_from_ssa_entry_value(state, entry, b, intrin, value,
nir_src_as_uint(src->arr.index));
}
/* An SSA copy_entry for the vector won't help indirect load. */
if (glsl_type_is_vector(entry->dst->type)) {
assert(entry->dst->type == nir_deref_instr_parent(src)->type);
/* TODO: If all SSA entries are there, try an if-ladder. */
return false;
}
}
*value = entry->src;
assert(value->is_ssa);
const struct glsl_type *type = entry->dst->type;
unsigned num_components = glsl_get_vector_elements(type);
nir_component_mask_t available = 0;
bool all_same = true;
for (unsigned i = 0; i < num_components; i++) {
if (value->ssa.def[i])
available |= (1 << i);
if (value->ssa.def[i] != value->ssa.def[0])
all_same = false;
if (value->ssa.component[i] != i)
all_same = false;
}
if (all_same) {
/* Our work here is done */
b->cursor = nir_instr_remove(&intrin->instr);
intrin->instr.block = NULL;
return true;
}
if (available != (1 << num_components) - 1 &&
intrin->intrinsic == nir_intrinsic_load_deref &&
(available & nir_ssa_def_components_read(&intrin->dest.ssa)) == 0) {
/* If none of the components read are available as SSA values, then we
* should just bail. Otherwise, we would end up replacing the uses of
* the load_deref a vecN() that just gathers up its components.
*/
return false;
}
b->cursor = nir_after_instr(&intrin->instr);
nir_ssa_def *load_def =
intrin->intrinsic == nir_intrinsic_load_deref ? &intrin->dest.ssa : NULL;
bool keep_intrin = false;
nir_ssa_def *comps[NIR_MAX_VEC_COMPONENTS];
for (unsigned i = 0; i < num_components; i++) {
if (value->ssa.def[i]) {
comps[i] = nir_channel(b, value->ssa.def[i], value->ssa.component[i]);
} else {
/* We don't have anything for this component in our
* list. Just re-use a channel from the load.
*/
if (load_def == NULL)
load_def = nir_load_deref(b, entry->dst);
if (load_def->parent_instr == &intrin->instr)
keep_intrin = true;
comps[i] = nir_channel(b, load_def, i);
}
}
nir_ssa_def *vec = nir_vec(b, comps, num_components);
value_set_ssa_components(value, vec, num_components);
if (!keep_intrin) {
/* Removing this instruction should not touch the cursor because we
* created the cursor after the intrinsic and have added at least one
* instruction (the vec) since then.
*/
assert(b->cursor.instr != &intrin->instr);
nir_instr_remove(&intrin->instr);
intrin->instr.block = NULL;
}
return true;
}
/**
* Specialize the wildcards in a deref chain
*
* This function returns a deref chain identical to \param deref except that
* some of its wildcards are replaced with indices from \param specific. The
* process is guided by \param guide which references the same type as \param
* specific but has the same wildcard array lengths as \param deref.
*/
static nir_deref_instr *
specialize_wildcards(nir_builder *b,
nir_deref_path *deref,
nir_deref_path *guide,
nir_deref_path *specific)
{
nir_deref_instr **deref_p = &deref->path[1];
nir_deref_instr **guide_p = &guide->path[1];
nir_deref_instr **spec_p = &specific->path[1];
nir_deref_instr *ret_tail = deref->path[0];
for (; *deref_p; deref_p++) {
if ((*deref_p)->deref_type == nir_deref_type_array_wildcard) {
/* This is where things get tricky. We have to search through
* the entry deref to find its corresponding wildcard and fill
* this slot in with the value from the src.
*/
while (*guide_p &&
(*guide_p)->deref_type != nir_deref_type_array_wildcard) {
guide_p++;
spec_p++;
}
assert(*guide_p && *spec_p);
ret_tail = nir_build_deref_follower(b, ret_tail, *spec_p);
guide_p++;
spec_p++;
} else {
ret_tail = nir_build_deref_follower(b, ret_tail, *deref_p);
}
}
return ret_tail;
}
/* Do a "load" from an deref-based entry return it in "value" as a value. The
* deref returned in "value" will always be a fresh copy so the caller can
* steal it and assign it to the instruction directly without copying it
* again.
*/
static bool
load_from_deref_entry_value(struct copy_prop_var_state *state,
struct copy_entry *entry,
nir_builder *b, nir_intrinsic_instr *intrin,
nir_deref_instr *src, struct value *value)
{
*value = entry->src;
b->cursor = nir_instr_remove(&intrin->instr);
nir_deref_path entry_dst_path, src_path;
nir_deref_path_init(&entry_dst_path, entry->dst, state->mem_ctx);
nir_deref_path_init(&src_path, src, state->mem_ctx);
bool need_to_specialize_wildcards = false;
nir_deref_instr **entry_p = &entry_dst_path.path[1];
nir_deref_instr **src_p = &src_path.path[1];
while (*entry_p && *src_p) {
nir_deref_instr *entry_tail = *entry_p++;
nir_deref_instr *src_tail = *src_p++;
if (src_tail->deref_type == nir_deref_type_array &&
entry_tail->deref_type == nir_deref_type_array_wildcard)
need_to_specialize_wildcards = true;
}
/* If the entry deref is longer than the source deref then it refers to a
* smaller type and we can't source from it.
*/
assert(*entry_p == NULL);
if (need_to_specialize_wildcards) {
/* The entry has some wildcards that are not in src. This means we need
* to construct a new deref based on the entry but using the wildcards
* from the source and guided by the entry dst. Oof.
*/
nir_deref_path entry_src_path;
nir_deref_path_init(&entry_src_path, entry->src.deref, state->mem_ctx);
value->deref = specialize_wildcards(b, &entry_src_path,
&entry_dst_path, &src_path);
nir_deref_path_finish(&entry_src_path);
}
/* If our source deref is longer than the entry deref, that's ok because
* it just means the entry deref needs to be extended a bit.
*/
while (*src_p) {
nir_deref_instr *src_tail = *src_p++;
value->deref = nir_build_deref_follower(b, value->deref, src_tail);
}
nir_deref_path_finish(&entry_dst_path);
nir_deref_path_finish(&src_path);
return true;
}
static bool
try_load_from_entry(struct copy_prop_var_state *state, struct copy_entry *entry,
nir_builder *b, nir_intrinsic_instr *intrin,
nir_deref_instr *src, struct value *value)
{
if (entry == NULL)
return false;
if (entry->src.is_ssa) {
return load_from_ssa_entry_value(state, entry, b, intrin, src, value);
} else {
return load_from_deref_entry_value(state, entry, b, intrin, src, value);
}
}
static void
invalidate_copies_for_cf_node(struct copy_prop_var_state *state,
struct util_dynarray *copies,
nir_cf_node *cf_node)
{
struct hash_entry *ht_entry = _mesa_hash_table_search(state->vars_written_map, cf_node);
assert(ht_entry);
struct vars_written *written = ht_entry->data;
if (written->modes) {
util_dynarray_foreach_reverse(copies, struct copy_entry, entry) {
if (nir_deref_mode_may_be(entry->dst, written->modes))
copy_entry_remove(copies, entry);
}
}
hash_table_foreach (written->derefs, entry) {
nir_deref_instr *deref_written = (nir_deref_instr *)entry->key;
kill_aliases(copies, deref_written, (uintptr_t)entry->data);
}
}
static void
print_value(struct value *value, unsigned num_components)
{
if (!value->is_ssa) {
printf(" %s ", glsl_get_type_name(value->deref->type));
nir_print_deref(value->deref, stdout);
return;
}
bool same_ssa = true;
for (unsigned i = 0; i < num_components; i++) {
if (value->ssa.component[i] != i ||
(i > 0 && value->ssa.def[i - 1] != value->ssa.def[i])) {
same_ssa = false;
break;
}
}
if (same_ssa) {
printf(" ssa_%d", value->ssa.def[0]->index);
} else {
for (int i = 0; i < num_components; i++) {
if (value->ssa.def[i])
printf(" ssa_%d[%u]", value->ssa.def[i]->index, value->ssa.component[i]);
else
printf(" _");
}
}
}
static void
print_copy_entry(struct copy_entry *entry)
{
printf(" %s ", glsl_get_type_name(entry->dst->type));
nir_print_deref(entry->dst, stdout);
printf(":\t");
unsigned num_components = glsl_get_vector_elements(entry->dst->type);
print_value(&entry->src, num_components);
printf("\n");
}
static void
dump_instr(nir_instr *instr)
{
printf(" ");
nir_print_instr(instr, stdout);
printf("\n");
}
static void
dump_copy_entries(struct util_dynarray *copies)
{
util_dynarray_foreach(copies, struct copy_entry, iter)
print_copy_entry(iter);
printf("\n");
}
static void
copy_prop_vars_block(struct copy_prop_var_state *state,
nir_builder *b, nir_block *block,
struct util_dynarray *copies)
{
if (debug) {
printf("# block%d\n", block->index);
dump_copy_entries(copies);
}
nir_foreach_instr_safe(instr, block) {
if (debug && instr->type == nir_instr_type_deref)
dump_instr(instr);
if (instr->type == nir_instr_type_call) {
if (debug) dump_instr(instr);
apply_barrier_for_modes(copies, nir_var_shader_out |
nir_var_shader_temp |
nir_var_function_temp |
nir_var_mem_ssbo |
nir_var_mem_shared |
nir_var_mem_global);
if (debug) dump_copy_entries(copies);
continue;
}
if (instr->type != nir_instr_type_intrinsic)
continue;
nir_intrinsic_instr *intrin = nir_instr_as_intrinsic(instr);
switch (intrin->intrinsic) {
case nir_intrinsic_control_barrier:
case nir_intrinsic_memory_barrier:
if (debug) dump_instr(instr);
apply_barrier_for_modes(copies, nir_var_shader_out |
nir_var_mem_ssbo |
nir_var_mem_shared |
nir_var_mem_global);
break;
case nir_intrinsic_memory_barrier_buffer:
if (debug) dump_instr(instr);
apply_barrier_for_modes(copies, nir_var_mem_ssbo |
nir_var_mem_global);
break;
case nir_intrinsic_memory_barrier_shared:
if (debug) dump_instr(instr);
apply_barrier_for_modes(copies, nir_var_mem_shared);
break;
case nir_intrinsic_memory_barrier_tcs_patch:
if (debug) dump_instr(instr);
apply_barrier_for_modes(copies, nir_var_shader_out);
break;
case nir_intrinsic_scoped_barrier:
if (debug) dump_instr(instr);
if (nir_intrinsic_memory_semantics(intrin) & NIR_MEMORY_ACQUIRE)
apply_barrier_for_modes(copies, nir_intrinsic_memory_modes(intrin));
break;
case nir_intrinsic_emit_vertex:
case nir_intrinsic_emit_vertex_with_counter:
if (debug) dump_instr(instr);
apply_barrier_for_modes(copies, nir_var_shader_out);
break;
case nir_intrinsic_report_ray_intersection:
apply_barrier_for_modes(copies, nir_var_mem_ssbo |
nir_var_mem_global |
nir_var_shader_call_data |
nir_var_ray_hit_attrib);
break;
case nir_intrinsic_ignore_ray_intersection:
case nir_intrinsic_terminate_ray:
apply_barrier_for_modes(copies, nir_var_mem_ssbo |
nir_var_mem_global |
nir_var_shader_call_data);
break;
case nir_intrinsic_load_deref: {
if (debug) dump_instr(instr);
if (nir_intrinsic_access(intrin) & ACCESS_VOLATILE)
break;
nir_deref_instr *src = nir_src_as_deref(intrin->src[0]);
/* Direct array_derefs of vectors operate on the vectors (the parent
* deref). Indirects will be handled like other derefs.
*/
int vec_index = 0;
nir_deref_instr *vec_src = src;
if (is_array_deref_of_vector(src) && nir_src_is_const(src->arr.index)) {
vec_src = nir_deref_instr_parent(src);
unsigned vec_comps = glsl_get_vector_elements(vec_src->type);
vec_index = nir_src_as_uint(src->arr.index);
/* Loading from an invalid index yields an undef */
if (vec_index >= vec_comps) {
b->cursor = nir_instr_remove(instr);
nir_ssa_def *u = nir_ssa_undef(b, 1, intrin->dest.ssa.bit_size);
nir_ssa_def_rewrite_uses(&intrin->dest.ssa, nir_src_for_ssa(u));
state->progress = true;
break;
}
}
struct copy_entry *src_entry =
lookup_entry_for_deref(copies, src, nir_derefs_a_contains_b_bit);
struct value value = {0};
if (try_load_from_entry(state, src_entry, b, intrin, src, &value)) {
if (value.is_ssa) {
/* lookup_load has already ensured that we get a single SSA
* value that has all of the channels. We just have to do the
* rewrite operation. Note for array derefs of vectors, the
* channel 0 is used.
*/
if (intrin->instr.block) {
/* The lookup left our instruction in-place. This means it
* must have used it to vec up a bunch of different sources.
* We need to be careful when rewriting uses so we don't
* rewrite the vecN itself.
*/
nir_ssa_def_rewrite_uses_after(&intrin->dest.ssa,
nir_src_for_ssa(value.ssa.def[0]),
value.ssa.def[0]->parent_instr);
} else {
nir_ssa_def_rewrite_uses(&intrin->dest.ssa,
nir_src_for_ssa(value.ssa.def[0]));
}
} else {
/* We're turning it into a load of a different variable */
intrin->src[0] = nir_src_for_ssa(&value.deref->dest.ssa);
/* Put it back in again. */
nir_builder_instr_insert(b, instr);
value_set_ssa_components(&value, &intrin->dest.ssa,
intrin->num_components);
}
state->progress = true;
} else {
value_set_ssa_components(&value, &intrin->dest.ssa,
intrin->num_components);
}
/* Now that we have a value, we're going to store it back so that we
* have the right value next time we come looking for it. In order
* to do this, we need an exact match, not just something that
* contains what we're looking for.
*/
struct copy_entry *entry =
lookup_entry_for_deref(copies, vec_src, nir_derefs_equal_bit);
if (!entry)
entry = copy_entry_create(copies, vec_src);
/* Update the entry with the value of the load. This way
* we can potentially remove subsequent loads.
*/
value_set_from_value(&entry->src, &value, vec_index,
(1 << intrin->num_components) - 1);
break;
}
case nir_intrinsic_store_deref: {
if (debug) dump_instr(instr);
nir_deref_instr *dst = nir_src_as_deref(intrin->src[0]);
assert(glsl_type_is_vector_or_scalar(dst->type));
/* Direct array_derefs of vectors operate on the vectors (the parent
* deref). Indirects will be handled like other derefs.
*/
int vec_index = 0;
nir_deref_instr *vec_dst = dst;
if (is_array_deref_of_vector(dst) && nir_src_is_const(dst->arr.index)) {
vec_dst = nir_deref_instr_parent(dst);
unsigned vec_comps = glsl_get_vector_elements(vec_dst->type);
vec_index = nir_src_as_uint(dst->arr.index);
/* Storing to an invalid index is a no-op. */
if (vec_index >= vec_comps) {
nir_instr_remove(instr);
state->progress = true;
break;
}
}
if (nir_intrinsic_access(intrin) & ACCESS_VOLATILE) {
unsigned wrmask = nir_intrinsic_write_mask(intrin);
kill_aliases(copies, dst, wrmask);
break;
}
struct copy_entry *entry =
lookup_entry_for_deref(copies, dst, nir_derefs_equal_bit);
if (entry && value_equals_store_src(&entry->src, intrin)) {
/* If we are storing the value from a load of the same var the
* store is redundant so remove it.
*/
nir_instr_remove(instr);
state->progress = true;
} else {
struct value value = {0};
value_set_ssa_components(&value, intrin->src[1].ssa,
intrin->num_components);
unsigned wrmask = nir_intrinsic_write_mask(intrin);
struct copy_entry *entry =
get_entry_and_kill_aliases(copies, vec_dst, wrmask);
value_set_from_value(&entry->src, &value, vec_index, wrmask);
}
break;
}
case nir_intrinsic_copy_deref: {
if (debug) dump_instr(instr);
nir_deref_instr *dst = nir_src_as_deref(intrin->src[0]);
nir_deref_instr *src = nir_src_as_deref(intrin->src[1]);
/* The copy_deref intrinsic doesn't keep track of num_components, so
* get it ourselves.
*/
unsigned num_components = glsl_get_vector_elements(dst->type);
unsigned full_mask = (1 << num_components) - 1;
if ((nir_intrinsic_src_access(intrin) & ACCESS_VOLATILE) ||
(nir_intrinsic_dst_access(intrin) & ACCESS_VOLATILE)) {
kill_aliases(copies, dst, full_mask);
break;
}
if (nir_compare_derefs(src, dst) & nir_derefs_equal_bit) {
/* This is a no-op self-copy. Get rid of it */
nir_instr_remove(instr);
state->progress = true;
continue;
}
/* Copy of direct array derefs of vectors are not handled. Just
* invalidate what's written and bail.
*/
if ((is_array_deref_of_vector(src) && nir_src_is_const(src->arr.index)) ||
(is_array_deref_of_vector(dst) && nir_src_is_const(dst->arr.index))) {
kill_aliases(copies, dst, full_mask);
break;
}
struct copy_entry *src_entry =
lookup_entry_for_deref(copies, src, nir_derefs_a_contains_b_bit);
struct value value;
if (try_load_from_entry(state, src_entry, b, intrin, src, &value)) {
/* If load works, intrin (the copy_deref) is removed. */
if (value.is_ssa) {
nir_store_deref(b, dst, value.ssa.def[0], full_mask);
} else {
/* If this would be a no-op self-copy, don't bother. */
if (nir_compare_derefs(value.deref, dst) & nir_derefs_equal_bit)
continue;
/* Just turn it into a copy of a different deref */
intrin->src[1] = nir_src_for_ssa(&value.deref->dest.ssa);
/* Put it back in again. */
nir_builder_instr_insert(b, instr);
}
state->progress = true;
} else {
value = (struct value) {
.is_ssa = false,
{ .deref = src },
};
}
nir_variable *src_var = nir_deref_instr_get_variable(src);
if (src_var && src_var->data.cannot_coalesce) {
/* The source cannot be coaleseced, which means we can't propagate
* this copy.
*/
break;
}
struct copy_entry *dst_entry =
get_entry_and_kill_aliases(copies, dst, full_mask);
value_set_from_value(&dst_entry->src, &value, 0, full_mask);
break;
}
case nir_intrinsic_trace_ray:
case nir_intrinsic_execute_callable: {
if (debug) dump_instr(instr);
nir_deref_instr *payload =
nir_src_as_deref(*nir_get_shader_call_payload_src(intrin));
nir_component_mask_t full_mask =
(nir_component_mask_t) BITFIELD_MASK(glsl_get_vector_elements(payload->type));
kill_aliases(copies, payload, full_mask);
break;
}
case nir_intrinsic_memcpy_deref:
case nir_intrinsic_deref_atomic_add:
case nir_intrinsic_deref_atomic_fadd:
case nir_intrinsic_deref_atomic_imin:
case nir_intrinsic_deref_atomic_umin:
case nir_intrinsic_deref_atomic_fmin:
case nir_intrinsic_deref_atomic_imax:
case nir_intrinsic_deref_atomic_umax:
case nir_intrinsic_deref_atomic_fmax:
case nir_intrinsic_deref_atomic_and:
case nir_intrinsic_deref_atomic_or:
case nir_intrinsic_deref_atomic_xor:
case nir_intrinsic_deref_atomic_exchange:
case nir_intrinsic_deref_atomic_comp_swap:
case nir_intrinsic_deref_atomic_fcomp_swap:
if (debug) dump_instr(instr);
nir_deref_instr *dst = nir_src_as_deref(intrin->src[0]);
unsigned num_components = glsl_get_vector_elements(dst->type);
unsigned full_mask = (1 << num_components) - 1;
kill_aliases(copies, dst, full_mask);
break;
case nir_intrinsic_store_deref_block_intel: {
if (debug) dump_instr(instr);
/* Invalidate the whole variable (or cast) and anything that alias
* with it.
*/
nir_deref_instr *dst = nir_src_as_deref(intrin->src[0]);
while (nir_deref_instr_parent(dst))
dst = nir_deref_instr_parent(dst);
assert(dst->deref_type == nir_deref_type_var ||
dst->deref_type == nir_deref_type_cast);
unsigned num_components = glsl_get_vector_elements(dst->type);
unsigned full_mask = (1 << num_components) - 1;
kill_aliases(copies, dst, full_mask);
break;
}
default:
continue; /* To skip the debug below. */
}
if (debug) dump_copy_entries(copies);
}
}
static void
copy_prop_vars_cf_node(struct copy_prop_var_state *state,
struct util_dynarray *copies,
nir_cf_node *cf_node)
{
switch (cf_node->type) {
case nir_cf_node_function: {
nir_function_impl *impl = nir_cf_node_as_function(cf_node);
struct util_dynarray impl_copies;
util_dynarray_init(&impl_copies, state->mem_ctx);
foreach_list_typed_safe(nir_cf_node, cf_node, node, &impl->body)
copy_prop_vars_cf_node(state, &impl_copies, cf_node);
break;
}
case nir_cf_node_block: {
nir_block *block = nir_cf_node_as_block(cf_node);
nir_builder b;
nir_builder_init(&b, state->impl);
copy_prop_vars_block(state, &b, block, copies);
break;
}
case nir_cf_node_if: {
nir_if *if_stmt = nir_cf_node_as_if(cf_node);
/* Clone the copies for each branch of the if statement. The idea is
* that they both see the same state of available copies, but do not
* interfere to each other.
*/
struct util_dynarray then_copies;
util_dynarray_clone(&then_copies, state->mem_ctx, copies);
struct util_dynarray else_copies;
util_dynarray_clone(&else_copies, state->mem_ctx, copies);
foreach_list_typed_safe(nir_cf_node, cf_node, node, &if_stmt->then_list)
copy_prop_vars_cf_node(state, &then_copies, cf_node);
foreach_list_typed_safe(nir_cf_node, cf_node, node, &if_stmt->else_list)
copy_prop_vars_cf_node(state, &else_copies, cf_node);
/* Both branches copies can be ignored, since the effect of running both
* branches was captured in the first pass that collects vars_written.
*/
invalidate_copies_for_cf_node(state, copies, cf_node);
break;
}
case nir_cf_node_loop: {
nir_loop *loop = nir_cf_node_as_loop(cf_node);
/* Invalidate before cloning the copies for the loop, since the loop
* body can be executed more than once.
*/
invalidate_copies_for_cf_node(state, copies, cf_node);
struct util_dynarray loop_copies;
util_dynarray_clone(&loop_copies, state->mem_ctx, copies);
foreach_list_typed_safe(nir_cf_node, cf_node, node, &loop->body)
copy_prop_vars_cf_node(state, &loop_copies, cf_node);
break;
}
default:
unreachable("Invalid CF node type");
}
}
static bool
nir_copy_prop_vars_impl(nir_function_impl *impl)
{
void *mem_ctx = ralloc_context(NULL);
if (debug) {
nir_metadata_require(impl, nir_metadata_block_index);
printf("## nir_copy_prop_vars_impl for %s\n", impl->function->name);
}
struct copy_prop_var_state state = {
.impl = impl,
.mem_ctx = mem_ctx,
.lin_ctx = linear_zalloc_parent(mem_ctx, 0),
.vars_written_map = _mesa_pointer_hash_table_create(mem_ctx),
};
gather_vars_written(&state, NULL, &impl->cf_node);
copy_prop_vars_cf_node(&state, NULL, &impl->cf_node);
if (state.progress) {
nir_metadata_preserve(impl, nir_metadata_block_index |
nir_metadata_dominance);
} else {
nir_metadata_preserve(impl, nir_metadata_all);
}
ralloc_free(mem_ctx);
return state.progress;
}
bool
nir_opt_copy_prop_vars(nir_shader *shader)
{
bool progress = false;
nir_foreach_function(function, shader) {
if (!function->impl)
continue;
progress |= nir_copy_prop_vars_impl(function->impl);
}
return progress;
}