[Mesa-dev] [PATCH v3 102/104] nir: Rework lower_locals_to_regs to use deref instructions
Jason Ekstrand
jason at jlekstrand.net
Tue Apr 3 18:39:46 UTC 2018
This completely reworks the pass to support deref instructions and
delete support for old deref chains
---
src/compiler/nir/nir_lower_locals_to_regs.c | 186 +++++++++++++---------------
src/intel/compiler/brw_nir.c | 2 -
2 files changed, 87 insertions(+), 101 deletions(-)
diff --git a/src/compiler/nir/nir_lower_locals_to_regs.c b/src/compiler/nir/nir_lower_locals_to_regs.c
index d0667bc..ec71f3d 100644
--- a/src/compiler/nir/nir_lower_locals_to_regs.c
+++ b/src/compiler/nir/nir_lower_locals_to_regs.c
@@ -26,10 +26,10 @@
*/
#include "nir.h"
+#include "nir_builder.h"
struct locals_to_regs_state {
- nir_shader *shader;
- nir_function_impl *impl;
+ nir_builder builder;
/* A hash table mapping derefs to registers */
struct hash_table *regs_table;
@@ -47,54 +47,61 @@ hash_deref(const void *void_deref)
{
uint32_t hash = _mesa_fnv32_1a_offset_bias;
- const nir_deref_var *deref_var = void_deref;
- hash = _mesa_fnv32_1a_accumulate(hash, deref_var->var);
+ for (const nir_deref_instr *deref = void_deref; deref;
+ deref = nir_deref_instr_parent(deref)) {
+ switch (deref->deref_type) {
+ case nir_deref_type_var:
+ return _mesa_fnv32_1a_accumulate(hash, deref->var);
- for (const nir_deref *deref = deref_var->deref.child;
- deref; deref = deref->child) {
- if (deref->deref_type == nir_deref_type_struct) {
- const nir_deref_struct *deref_struct = nir_deref_as_struct(deref);
- hash = _mesa_fnv32_1a_accumulate(hash, deref_struct->index);
+ case nir_deref_type_array:
+ continue; /* Do nothing */
+
+ case nir_deref_type_struct:
+ hash = _mesa_fnv32_1a_accumulate(hash, deref->strct.index);
+ continue;
+
+ default:
+ unreachable("Invalid deref type");
}
}
- return hash;
+ unreachable("We should have hit a variable dereference");
}
static bool
derefs_equal(const void *void_a, const void *void_b)
{
- const nir_deref_var *a_var = void_a;
- const nir_deref_var *b_var = void_b;
-
- if (a_var->var != b_var->var)
- return false;
-
- for (const nir_deref *a = a_var->deref.child, *b = b_var->deref.child;
- a != NULL; a = a->child, b = b->child) {
+ for (const nir_deref_instr *a = void_a, *b = void_b; a || b;
+ a = nir_deref_instr_parent(a), b = nir_deref_instr_parent(b)) {
if (a->deref_type != b->deref_type)
return false;
- if (a->deref_type == nir_deref_type_struct) {
- if (nir_deref_as_struct(a)->index != nir_deref_as_struct(b)->index)
+ switch (a->deref_type) {
+ case nir_deref_type_var:
+ return a->var == b->var;
+
+ case nir_deref_type_array:
+ continue; /* Do nothing */
+
+ case nir_deref_type_struct:
+ if (a->strct.index != b->strct.index)
return false;
- }
- /* Do nothing for arrays. They're all the same. */
+ continue;
- assert((a->child == NULL) == (b->child == NULL));
- if((a->child == NULL) != (b->child == NULL))
- return false;
+ default:
+ unreachable("Invalid deref type");
+ }
}
- return true;
+ unreachable("We should have hit a variable dereference");
}
static nir_register *
-get_reg_for_deref(nir_deref_var *deref, struct locals_to_regs_state *state)
+get_reg_for_deref(nir_deref_instr *deref, struct locals_to_regs_state *state)
{
uint32_t hash = hash_deref(deref);
- assert(deref->var->constant_initializer == NULL);
+ assert(nir_deref_instr_get_variable(deref)->constant_initializer == NULL);
struct hash_entry *entry =
_mesa_hash_table_search_pre_hashed(state->regs_table, hash, deref);
@@ -102,19 +109,17 @@ get_reg_for_deref(nir_deref_var *deref, struct locals_to_regs_state *state)
return entry->data;
unsigned array_size = 1;
- nir_deref *tail = &deref->deref;
- while (tail->child) {
- if (tail->child->deref_type == nir_deref_type_array)
- array_size *= glsl_get_length(tail->type);
- tail = tail->child;
+ for (nir_deref_instr *d = deref; d; d = nir_deref_instr_parent(d)) {
+ if (d->deref_type == nir_deref_type_array)
+ array_size *= glsl_get_length(nir_deref_instr_parent(d)->type);
}
- assert(glsl_type_is_vector(tail->type) || glsl_type_is_scalar(tail->type));
+ assert(glsl_type_is_vector_or_scalar(deref->type));
- nir_register *reg = nir_local_reg_create(state->impl);
- reg->num_components = glsl_get_vector_elements(tail->type);
+ nir_register *reg = nir_local_reg_create(state->builder.impl);
+ reg->num_components = glsl_get_vector_elements(deref->type);
reg->num_array_elems = array_size > 1 ? array_size : 0;
- reg->bit_size = glsl_get_bit_size(tail->type);
+ reg->bit_size = glsl_get_bit_size(deref->type);
_mesa_hash_table_insert_pre_hashed(state->regs_table, hash, deref, reg);
@@ -122,9 +127,10 @@ get_reg_for_deref(nir_deref_var *deref, struct locals_to_regs_state *state)
}
static nir_src
-get_deref_reg_src(nir_deref_var *deref, nir_instr *instr,
- struct locals_to_regs_state *state)
+get_deref_reg_src(nir_deref_instr *deref, struct locals_to_regs_state *state)
{
+ nir_builder *b = &state->builder;
+
nir_src src;
src.is_ssa = false;
@@ -140,55 +146,32 @@ get_deref_reg_src(nir_deref_var *deref, nir_instr *instr,
if (src.reg.reg->num_array_elems == 0)
return src;
- nir_deref *tail = &deref->deref;
- while (tail->child != NULL) {
- const struct glsl_type *parent_type = tail->type;
- tail = tail->child;
-
- if (tail->deref_type != nir_deref_type_array)
+ unsigned inner_array_size = 1;
+ for (const nir_deref_instr *d = deref; d; d = nir_deref_instr_parent(d)) {
+ if (d->deref_type != nir_deref_type_array)
continue;
- nir_deref_array *deref_array = nir_deref_as_array(tail);
-
- src.reg.base_offset *= glsl_get_length(parent_type);
- src.reg.base_offset += deref_array->base_offset;
-
- if (src.reg.indirect) {
- nir_load_const_instr *load_const =
- nir_load_const_instr_create(state->shader, 1, 32);
- load_const->value.u32[0] = glsl_get_length(parent_type);
- nir_instr_insert_before(instr, &load_const->instr);
-
- nir_alu_instr *mul = nir_alu_instr_create(state->shader, nir_op_imul);
- mul->src[0].src = *src.reg.indirect;
- mul->src[1].src.is_ssa = true;
- mul->src[1].src.ssa = &load_const->def;
- mul->dest.write_mask = 1;
- nir_ssa_dest_init(&mul->instr, &mul->dest.dest, 1, 32, NULL);
- nir_instr_insert_before(instr, &mul->instr);
-
- src.reg.indirect->is_ssa = true;
- src.reg.indirect->ssa = &mul->dest.dest.ssa;
- }
-
- if (deref_array->deref_array_type == nir_deref_array_type_indirect) {
- if (src.reg.indirect == NULL) {
- src.reg.indirect = ralloc(state->shader, nir_src);
- nir_src_copy(src.reg.indirect, &deref_array->indirect,
- state->shader);
+ nir_const_value *const_index = nir_src_as_const_value(d->arr.index);
+ if (const_index && !src.reg.indirect) {
+ src.reg.base_offset += const_index->u32[0] * inner_array_size;
+ } else {
+ if (src.reg.indirect) {
+ assert(src.reg.base_offset == 0);
} else {
- nir_alu_instr *add = nir_alu_instr_create(state->shader,
- nir_op_iadd);
- add->src[0].src = *src.reg.indirect;
- nir_src_copy(&add->src[1].src, &deref_array->indirect, add);
- add->dest.write_mask = 1;
- nir_ssa_dest_init(&add->instr, &add->dest.dest, 1, 32, NULL);
- nir_instr_insert_before(instr, &add->instr);
-
- src.reg.indirect->is_ssa = true;
- src.reg.indirect->ssa = &add->dest.dest.ssa;
+ src.reg.indirect = ralloc(b->shader, nir_src);
+ *src.reg.indirect =
+ nir_src_for_ssa(nir_imm_int(b, src.reg.base_offset));
+ src.reg.base_offset = 0;
}
+
+ assert(src.reg.indirect->is_ssa);
+ src.reg.indirect->ssa =
+ nir_iadd(b, src.reg.indirect->ssa,
+ nir_imul(b, nir_ssa_for_src(b, d->arr.index, 1),
+ nir_imm_int(b, inner_array_size)));
}
+
+ inner_array_size *= glsl_get_length(nir_deref_instr_parent(d)->type);
}
return src;
@@ -198,6 +181,8 @@ static bool
lower_locals_to_regs_block(nir_block *block,
struct locals_to_regs_state *state)
{
+ nir_builder *b = &state->builder;
+
nir_foreach_instr_safe(instr, block) {
if (instr->type != nir_instr_type_intrinsic)
continue;
@@ -205,13 +190,15 @@ lower_locals_to_regs_block(nir_block *block,
nir_intrinsic_instr *intrin = nir_instr_as_intrinsic(instr);
switch (intrin->intrinsic) {
- case nir_intrinsic_load_var: {
- if (intrin->variables[0]->var->data.mode != nir_var_local)
+ case nir_intrinsic_load_deref: {
+ nir_deref_instr *deref = nir_src_as_deref(intrin->src[0]);
+ if (deref->mode != nir_var_local)
continue;
- nir_alu_instr *mov = nir_alu_instr_create(state->shader, nir_op_imov);
- mov->src[0].src = get_deref_reg_src(intrin->variables[0],
- &intrin->instr, state);
+ b->cursor = nir_before_instr(&intrin->instr);
+
+ nir_alu_instr *mov = nir_alu_instr_create(b->shader, nir_op_imov);
+ mov->src[0].src = get_deref_reg_src(deref, state);
mov->dest.write_mask = (1 << intrin->num_components) - 1;
if (intrin->dest.is_ssa) {
nir_ssa_dest_init(&mov->instr, &mov->dest.dest,
@@ -222,36 +209,38 @@ lower_locals_to_regs_block(nir_block *block,
} else {
nir_dest_copy(&mov->dest.dest, &intrin->dest, &mov->instr);
}
- nir_instr_insert_before(&intrin->instr, &mov->instr);
+ nir_builder_instr_insert(b, &mov->instr);
nir_instr_remove(&intrin->instr);
state->progress = true;
break;
}
- case nir_intrinsic_store_var: {
- if (intrin->variables[0]->var->data.mode != nir_var_local)
+ case nir_intrinsic_store_deref: {
+ nir_deref_instr *deref = nir_src_as_deref(intrin->src[0]);
+ if (deref->mode != nir_var_local)
continue;
- nir_src reg_src = get_deref_reg_src(intrin->variables[0],
- &intrin->instr, state);
+ b->cursor = nir_before_instr(&intrin->instr);
+
+ nir_src reg_src = get_deref_reg_src(deref, state);
- nir_alu_instr *mov = nir_alu_instr_create(state->shader, nir_op_imov);
- nir_src_copy(&mov->src[0].src, &intrin->src[0], mov);
+ nir_alu_instr *mov = nir_alu_instr_create(b->shader, nir_op_imov);
+ nir_src_copy(&mov->src[0].src, &intrin->src[1], mov);
mov->dest.write_mask = nir_intrinsic_write_mask(intrin);
mov->dest.dest.is_ssa = false;
mov->dest.dest.reg.reg = reg_src.reg.reg;
mov->dest.dest.reg.base_offset = reg_src.reg.base_offset;
mov->dest.dest.reg.indirect = reg_src.reg.indirect;
- nir_instr_insert_before(&intrin->instr, &mov->instr);
+ nir_builder_instr_insert(b, &mov->instr);
nir_instr_remove(&intrin->instr);
state->progress = true;
break;
}
- case nir_intrinsic_copy_var:
+ case nir_intrinsic_copy_deref:
unreachable("There should be no copies whatsoever at this point");
break;
@@ -268,8 +257,7 @@ nir_lower_locals_to_regs_impl(nir_function_impl *impl)
{
struct locals_to_regs_state state;
- state.shader = impl->function->shader;
- state.impl = impl;
+ nir_builder_init(&state.builder, impl);
state.progress = false;
state.regs_table = _mesa_hash_table_create(NULL, hash_deref, derefs_equal);
diff --git a/src/intel/compiler/brw_nir.c b/src/intel/compiler/brw_nir.c
index 38a43ed..69ab162 100644
--- a/src/intel/compiler/brw_nir.c
+++ b/src/intel/compiler/brw_nir.c
@@ -740,8 +740,6 @@ brw_postprocess_nir(nir_shader *nir, const struct brw_compiler *compiler,
OPT(nir_opt_dce);
OPT(nir_opt_move_comparisons);
- OPT(nir_lower_deref_instrs, nir_lower_load_store_derefs);
-
OPT(nir_lower_locals_to_regs);
if (unlikely(debug_enabled)) {
--
2.5.0.400.gff86faf
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