On Mon, Nov 5, 2018 at 8:58 PM Timothy Arceri <tarc...@itsqueeze.com> wrote:
> Once linking opts are done this pass recombines varying components.
>
> This patch is loosely based on Connor's vectorize alu pass.
>
> V2: skip fragment shaders
>
> V3:
> - dont accidentally vectorise local vars
> - pass correct component to create_new_store()
> ---
> src/compiler/Makefile.sources | 1 +
> src/compiler/nir/meson.build | 1 +
> src/compiler/nir/nir.h | 2 +
> src/compiler/nir/nir_opt_vectorize_io.c | 527 ++++++++++++++++++++++++
> 4 files changed, 531 insertions(+)
> create mode 100644 src/compiler/nir/nir_opt_vectorize_io.c
>
> diff --git a/src/compiler/Makefile.sources b/src/compiler/Makefile.sources
> index ae170f02e82..5991df5a61c 100644
> --- a/src/compiler/Makefile.sources
> +++ b/src/compiler/Makefile.sources
> @@ -290,6 +290,7 @@ NIR_FILES = \
> nir/nir_opt_shrink_load.c \
> nir/nir_opt_trivial_continues.c \
> nir/nir_opt_undef.c \
> + nir/nir_opt_vectorize_io.c \
> nir/nir_phi_builder.c \
> nir/nir_phi_builder.h \
> nir/nir_print.c \
> diff --git a/src/compiler/nir/meson.build b/src/compiler/nir/meson.build
> index b0c3a7feb31..9555cc40e21 100644
> --- a/src/compiler/nir/meson.build
> +++ b/src/compiler/nir/meson.build
> @@ -174,6 +174,7 @@ files_libnir = files(
> 'nir_opt_shrink_load.c',
> 'nir_opt_trivial_continues.c',
> 'nir_opt_undef.c',
> + 'nir_opt_vectorize_io.c',
> 'nir_phi_builder.c',
> 'nir_phi_builder.h',
> 'nir_print.c',
> diff --git a/src/compiler/nir/nir.h b/src/compiler/nir/nir.h
> index a0ae9a4430e..79bbdedaf00 100644
> --- a/src/compiler/nir/nir.h
> +++ b/src/compiler/nir/nir.h
> @@ -3105,6 +3105,8 @@ bool nir_opt_trivial_continues(nir_shader *shader);
>
> bool nir_opt_undef(nir_shader *shader);
>
> +bool nir_opt_vectorize_io(nir_shader *shader, bool skip_fs_inputs);
> +
> bool nir_opt_conditional_discard(nir_shader *shader);
>
> void nir_sweep(nir_shader *shader);
> diff --git a/src/compiler/nir/nir_opt_vectorize_io.c
> b/src/compiler/nir/nir_opt_vectorize_io.c
> new file mode 100644
> index 00000000000..c2ab30d307b
> --- /dev/null
> +++ b/src/compiler/nir/nir_opt_vectorize_io.c
> @@ -0,0 +1,527 @@
> +/*
> + * Copyright © 2018 Timothy Arceri
> + *
> + * 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/u_dynarray.h"
> +#include "util/u_math.h"
> +
> +/** @file nir_opt_vectorize_io.c
> + *
> + * Replaces scalar nir_load_input/nir_store_output operations with
> + * vectorized instructions.
> + */
> +
> +static bool
> +is_io_load(nir_intrinsic_instr *intr)
> +{
> + switch (intr->intrinsic) {
> + case nir_intrinsic_interp_deref_at_centroid:
> + case nir_intrinsic_interp_deref_at_sample:
> + case nir_intrinsic_interp_deref_at_offset:
> + case nir_intrinsic_load_deref:
> + return true;
> + default:
> + return false;
> + }
> +}
> +
> +static nir_deref_instr *
> +clone_deref_array(nir_builder *b, nir_deref_instr *dst_tail,
> + const nir_deref_instr *src_head)
> +{
> + const nir_deref_instr *parent = nir_deref_instr_parent(src_head);
> +
> + if (!parent)
> + return dst_tail;
> +
> + assert(src_head->deref_type == nir_deref_type_array);
> +
> + dst_tail = clone_deref_array(b, dst_tail, parent);
> +
> + return nir_build_deref_array(b, dst_tail,
> + nir_ssa_for_src(b, src_head->arr.index,
> 1));
> +}
> +
> +static bool
> +instr_can_rewrite(nir_instr *instr)
> +{
> + if (instr->type != nir_instr_type_intrinsic)
> + return false;
> +
> + nir_intrinsic_instr *intr = nir_instr_as_intrinsic(instr);
> +
> + if (intr->num_components != 1)
> + return false;
> +
> + if (!is_io_load(intr) &&
> + intr->intrinsic != nir_intrinsic_store_deref)
> + return false;
> +
> + nir_variable *var =
> + nir_deref_instr_get_variable(nir_src_as_deref(intr->src[0]));
> +
> + if (var->data.mode != nir_var_shader_in &&
> + var->data.mode != nir_var_shader_out)
> + return false;
>
Please check deref->mode before calling nir_deref_instr_get_variable so the
pass doesn't trip up on incomplete deref chains. We know shader_in/out are
currently safe but we can't get the variable in general.
> +
> + /* TODO: add doubles support ? */
> + if (glsl_type_is_64bit(glsl_without_array(var->type)))
>
Maybe
if (glsl_get_bit_size(glsl_without_array(var->type)) != 32)
instead to be more future-proof?
+ return false;
> +
> + /* Only touch user defined varyings as these are the only ones we
> split */
> + if (var->data.location < VARYING_SLOT_VAR0 && var->data.location >= 0)
>
Why are we allowing negative locations?
> + return false;
> +
> + /* Skip complex types we don't split in the first place */
> + if (glsl_type_is_matrix(glsl_without_array(var->type)) ||
> + glsl_type_is_struct(glsl_without_array(var->type)))
> + return false;
>
if (!glsl_type_is_vector_or_scalar(glsl_without_array(var->type)))
instead? For that matter, glsl_type_is_scalar?
> +
> + return true;
> +}
> +
> +static bool
> +io_access_same_var(const nir_instr *instr1, const nir_instr *instr2)
> +{
> + assert(instr1->type == nir_instr_type_intrinsic &&
> + instr2->type == nir_instr_type_intrinsic);
> +
> + nir_intrinsic_instr *intr1 = nir_instr_as_intrinsic(instr1);
> + nir_intrinsic_instr *intr2 = nir_instr_as_intrinsic(instr2);
> +
> + nir_variable *var1 =
> + nir_deref_instr_get_variable(nir_src_as_deref(intr1->src[0]));
> + nir_variable *var2 =
> + nir_deref_instr_get_variable(nir_src_as_deref(intr2->src[0]));
> +
> + /* We don't handle combining vars of different type e.g. different
> array
> + * lengths so just skip if the type doesn't match.
> + */
> + if (var1->type != var2->type)
>
Above, we allow vectors (maybe a mistake?) but here, we would fail to
combine vec2 and float.
> + return false;
> +
> + if (is_io_load(intr1) != is_io_load(intr2))
> + return false;
> +
> + if (var1->data.location != var2->data.location)
> + return false;
> +
> + return true;
> +}
> +
> +static struct util_dynarray *
> +vec_instr_stack_create(void *mem_ctx)
> +{
> + struct util_dynarray *stack = ralloc(mem_ctx, struct util_dynarray);
> + util_dynarray_init(stack, mem_ctx);
> + return stack;
> +}
> +
> +static void
> +vec_instr_stack_push(struct util_dynarray *stack, nir_instr *instr)
> +{
> + util_dynarray_append(stack, nir_instr *, instr);
> +}
> +
> +static void
> +create_new_load(nir_builder *b, nir_intrinsic_instr *intr, nir_variable
> *var,
> + unsigned comp, unsigned num_comps)
> +{
> + b->cursor = nir_before_instr(&intr->instr);
> +
> + assert(intr->dest.is_ssa);
> +
> + nir_intrinsic_instr *new_intr =
> + nir_intrinsic_instr_create(b->shader, intr->intrinsic);
> + nir_ssa_dest_init(&new_intr->instr, &new_intr->dest, num_comps,
> + intr->dest.ssa.bit_size, NULL);
> + new_intr->num_components = num_comps;
> +
> + nir_deref_instr *deref = nir_build_deref_var(b, var);
> + deref = clone_deref_array(b, deref, nir_src_as_deref(intr->src[0]));
> +
> + new_intr->src[0] = nir_src_for_ssa(&deref->dest.ssa);
> +
> + if (intr->intrinsic == nir_intrinsic_interp_deref_at_offset ||
> + intr->intrinsic == nir_intrinsic_interp_deref_at_sample)
> + nir_src_copy(&new_intr->src[1], &intr->src[1], &new_intr->instr);
> +
> + nir_builder_instr_insert(b, &new_intr->instr);
> +
> + unsigned channel = comp - var->data.location_frac;
> + nir_ssa_def *load = nir_channel(b, &new_intr->dest.ssa, channel);
> + nir_ssa_def_rewrite_uses(&intr->dest.ssa, nir_src_for_ssa(load));
> +
> + /* Remove the old load intrinsic */
> + nir_instr_remove(&intr->instr);
> +}
> +
> +static void
> +create_new_store(nir_builder *b, nir_intrinsic_instr *intr, nir_variable
> *var,
> + nir_ssa_def **srcs, unsigned first_comp, unsigned
> num_comps)
> +{
> + b->cursor = nir_before_instr(&intr->instr);
> +
> + nir_intrinsic_instr *new_intr =
> + nir_intrinsic_instr_create(b->shader, intr->intrinsic);
> + new_intr->num_components = num_comps;
> +
> + nir_intrinsic_set_write_mask(new_intr, (1 << num_comps) - 1);
> +
> + nir_deref_instr *deref = nir_build_deref_var(b, var);
> + deref = clone_deref_array(b, deref, nir_src_as_deref(intr->src[0]));
> +
> + new_intr->src[0] = nir_src_for_ssa(&deref->dest.ssa);
> +
> + nir_ssa_def *stores[4];
> + for (unsigned i = 0; i < num_comps; i++) {
> + stores[i] = srcs[first_comp + i];
> + }
> +
> + new_intr->src[1] = nir_src_for_ssa(nir_vec(b, stores, num_comps));
> +
> + nir_builder_instr_insert(b, &new_intr->instr);
> +
> + /* Remove the old store intrinsic */
> + nir_instr_remove(&intr->instr);
> +}
> +
> +static bool
> +vec_instr_stack_pop(nir_builder *b, struct util_dynarray *stack,
> + nir_instr *instr,
> + nir_variable *input_vars[MAX_VARYINGS_INCL_PATCH][4],
> + nir_variable *output_vars[MAX_VARYINGS_INCL_PATCH][4])
> +{
> + nir_instr *last = util_dynarray_pop(stack, nir_instr *);
> +
> + assert(last == instr);
> + assert(last->type == nir_instr_type_intrinsic);
> +
> + nir_intrinsic_instr *intr = nir_instr_as_intrinsic(last);
> + nir_variable *var =
> + nir_deref_instr_get_variable(nir_src_as_deref(intr->src[0]));
> + unsigned loc = var->data.location - VARYING_SLOT_VAR0;
> +
> + nir_variable *new_var;
> + if (var->data.mode == nir_var_shader_in)
> + new_var = input_vars[loc][var->data.location_frac];
> + else
> + new_var = output_vars[loc][var->data.location_frac];
> +
> + unsigned num_comps =
> + glsl_get_vector_elements(glsl_without_array(new_var->type));
> +
> + /* Don't bother walking the stack if this component can't be
> vectorised. */
> + if (num_comps == 1)
> + return false;
> +
> + if (new_var == var)
> + return false;
> +
> + if (is_io_load(intr)) {
> + create_new_load(b, intr, new_var, var->data.location_frac,
> num_comps);
> + return true;
> + }
> +
> + b->cursor = nir_before_instr(last);
> + nir_ssa_undef_instr *instr_undef =
> + nir_ssa_undef_instr_create(b->shader, 1, 32);
> + nir_builder_instr_insert(b, &instr_undef->instr);
> +
> + nir_ssa_def *srcs[4];
> + for (int i = 0; i < 4; i++) {
> + srcs[i] = &instr_undef->def;
> + }
> + srcs[var->data.location_frac] = intr->src[1].ssa;
> +
> + util_dynarray_foreach_reverse(stack, nir_instr *, stack_instr) {
> + nir_intrinsic_instr *intr2 = nir_instr_as_intrinsic(*stack_instr);
> + nir_variable *var2 =
> + nir_deref_instr_get_variable(nir_src_as_deref(intr2->src[0]));
> + unsigned loc2 = var2->data.location - VARYING_SLOT_VAR0;
> +
> + if (output_vars[loc][var->data.location_frac] !=
> + output_vars[loc2][var2->data.location_frac])
> + continue;
> +
> + assert(glsl_get_vector_elements(glsl_without_array(var2->type)) ==
> 1);
> +
> + if (srcs[var2->data.location_frac] == &instr_undef->def) {
> + assert(intr2->src[1].is_ssa);
> + assert(intr2->src[1].ssa);
> +
> + srcs[var2->data.location_frac] = intr2->src[1].ssa;
> + }
> + }
> +
> + create_new_store(b, intr, new_var, srcs, new_var->data.location_frac,
> + num_comps);
> +
> + return true;
> +}
> +
> +static bool
> +cmp_func(const void *data1, const void *data2)
> +{
> + const struct util_dynarray *arr1 = data1;
> + const struct util_dynarray *arr2 = data2;
> +
> + const nir_instr *instr1 = *(nir_instr **)util_dynarray_begin(arr1);
> + const nir_instr *instr2 = *(nir_instr **)util_dynarray_begin(arr2);
> +
> + return io_access_same_var(instr1, instr2);
> +}
> +
> +#define HASH(hash, data) _mesa_fnv32_1a_accumulate((hash), (data))
> +
> +static uint32_t
> +hash_instr(const nir_instr *instr)
> +{
> + assert(instr->type == nir_instr_type_intrinsic);
> +
> + nir_intrinsic_instr *intr = nir_instr_as_intrinsic(instr);
> + nir_variable *var =
> + nir_deref_instr_get_variable(nir_src_as_deref(intr->src[0]));
> +
> + uint32_t hash = _mesa_fnv32_1a_offset_bias;
> + bool is_load = is_io_load(intr);
> +
> + hash = HASH(hash, var->type);
> + hash = HASH(hash, is_load);
> + return HASH(hash, var->data.location);
> +}
> +
> +static uint32_t
> +hash_stack(const void *data)
> +{
> + const struct util_dynarray *stack = data;
> + const nir_instr *first = *(nir_instr **)util_dynarray_begin(stack);
> + return hash_instr(first);
> +}
> +
> +static struct set *
> +vec_instr_set_create(void)
> +{
> + return _mesa_set_create(NULL, hash_stack, cmp_func);
> +}
> +
> +static void
> +vec_instr_set_destroy(struct set *instr_set)
> +{
> + _mesa_set_destroy(instr_set, NULL);
> +}
> +
> +static void
> +vec_instr_set_add(struct set *instr_set, nir_instr *instr)
> +{
> + if (!instr_can_rewrite(instr))
> + return;
> +
> + struct util_dynarray *new_stack = vec_instr_stack_create(instr_set);
> + vec_instr_stack_push(new_stack, instr);
> +
> + struct set_entry *entry = _mesa_set_search(instr_set, new_stack);
> +
> + if (entry) {
> + ralloc_free(new_stack);
> + struct util_dynarray *stack = (struct util_dynarray *) entry->key;
> + vec_instr_stack_push(stack, instr);
> + return;
> + }
> +
> + _mesa_set_add(instr_set, new_stack);
> + return;
> +}
> +
> +static bool
> +vec_instr_set_remove(nir_builder *b, struct set *instr_set, nir_instr
> *instr,
> + nir_variable *input_vars[MAX_VARYINGS_INCL_PATCH][4],
> + nir_variable
> *output_vars[MAX_VARYINGS_INCL_PATCH][4])
> +{
> + if (!instr_can_rewrite(instr))
> + return false;
> +
> + /*
> + * It's pretty unfortunate that we have to do this, but it's a side
> effect
> + * of the hash set interfaces. The hash set assumes that we're only
> + * interested in storing one equivalent element at a time, and if we
> try to
> + * insert a duplicate element it will remove the original. We could
> hack up
> + * the comparison function to "know" which input is an instruction we
> + * passed in and which is an array that's part of the entry, but that
> + * wouldn't work because we need to pass an array to _mesa_set_add() in
> + * vec_instr_add() above, and _mesa_set_add() will call our comparison
> + * function as well.
> + */
> + struct util_dynarray *temp = vec_instr_stack_create(instr_set);
> + vec_instr_stack_push(temp, instr);
> + struct set_entry *entry = _mesa_set_search(instr_set, temp);
> + ralloc_free(temp);
> +
> + if (entry) {
> + struct util_dynarray *stack = (struct util_dynarray *) entry->key;
> + bool progress = vec_instr_stack_pop(b, stack, instr, input_vars,
> + output_vars);
> +
> + if (!util_dynarray_num_elements(stack, nir_instr *))
> + _mesa_set_remove(instr_set, entry);
> +
> + return progress;
> + }
> +
> + return false;
> +}
> +
> +static bool
> +vectorize_block(nir_builder *b, nir_block *block, struct set *instr_set,
> + nir_variable *input_vars[MAX_VARYINGS_INCL_PATCH][4],
> + nir_variable *output_vars[MAX_VARYINGS_INCL_PATCH][4])
>
No comments on the actal meat of it yet except one: Why is it so
complicated??? For inputs, just change loads to load the whole vector and
insert a swizzle after it to grab the component you want. CSE will come
along and clean up the mess by and large. For stores, it's a bit more
complicated but it still doesn't seem like it needs to be this bad.
> +{
> + bool progress = false;
> +
> + nir_foreach_instr_safe(instr, block) {
> + vec_instr_set_add(instr_set, instr);
> + }
> +
> + for (unsigned i = 0; i < block->num_dom_children; i++) {
> + nir_block *child = block->dom_children[i];
> + progress |= vectorize_block(b, child, instr_set, input_vars,
> + output_vars);
> + }
> +
> + nir_foreach_instr_reverse_safe(instr, block) {
> + progress |= vec_instr_set_remove(b, instr_set, instr, input_vars,
> + output_vars);
> + }
> +
> + return progress;
> +}
> +
> +static void
> +create_new_io_var(nir_shader *shader,
> + nir_variable *vars[MAX_VARYINGS_INCL_PATCH][4],
> + unsigned location, unsigned comps)
> +{
> + unsigned num_comps = util_bitcount(comps);
>
Do we need to do anything if num_comps == 1? Or can we just leave it alone?
> + unsigned first_comp = u_bit_scan(&comps);
>
Might be worth a quick comment here that we're taking a component off.
Using u_bit_scan here is very nice from the perspective that it helps the
loop below but it's not obviuos.
> +
> + nir_variable *var = nir_variable_clone(vars[location][first_comp],
> shader);
> + var->data.location_frac = first_comp;
> + var->type = glsl_replace_vector_type(var->type, num_comps);
> +
> + nir_shader_add_variable(shader, var);
> +
> + vars[location][first_comp] = var;
> +
> + while (comps) {
> + const int comp = u_bit_scan(&comps);
> + vars[location][comp] = var;
> + }
> +}
> +
> +static void
> +create_new_io_vars(nir_shader *shader, struct exec_list *io_list,
> + nir_variable *vars[MAX_VARYINGS_INCL_PATCH][4])
> +{
> + if (exec_list_is_empty(io_list))
> + return;
> +
> + nir_foreach_variable(var, io_list) {
> + if (var->data.location >= VARYING_SLOT_VAR0) {
>
Do we want to check that it's a (possibly array of) scalar or anything like
that?
> + unsigned loc = var->data.location - VARYING_SLOT_VAR0;
> + vars[loc][var->data.location_frac] = var;
> + }
> + }
> +
> + /* We don't handle combining vars of different type e.g. different
> array
> + * lengths.
> + */
> + for (unsigned i = 0; i < MAX_VARYINGS_INCL_PATCH; i++) {
> + unsigned comps = 0;
> + for (unsigned j = 0; j < 3; j++) {
> + if (vars[i][j] && vars[i][j+1] && vars[i][j]->type ==
> vars[i][j+1]->type) {
> + if (j == 2) {
> + /* last component so create new variable */
> + comps |= 3 << vars[i][j]->data.location_frac;
>
Why not move setting comps out of the if? Might make things clearer.
> + create_new_io_var(shader, vars, i, comps);
> + } else {
> + /* Set comps */
> + comps |= 3 << vars[i][j]->data.location_frac;
> + }
> + } else {
> + if (comps) {
> + /* Types didn't match but we have already seen matching
> types
> + * at this location so create a new variable for those
> + * components.
> + */
> + create_new_io_var(shader, vars, i, comps);
> + comps = 0;
> + }
> + }
> + }
> + }
> +}
> +
> +static bool
> +nir_opt_vectorize_io_impl(nir_function_impl *impl)
> +{
> + nir_builder b;
> + nir_builder_init(&b, impl);
> +
> + nir_metadata_require(impl, nir_metadata_dominance);
> +
> + nir_shader *shader = impl->function->shader;
> + nir_variable *input_vars[MAX_VARYINGS_INCL_PATCH][4] = {0};
> + nir_variable *output_vars[MAX_VARYINGS_INCL_PATCH][4] = {0};
> +
> + create_new_io_vars(shader, &shader->inputs, input_vars);
> + create_new_io_vars(shader, &shader->outputs, output_vars);
> +
> + struct set *instr_set = vec_instr_set_create();
> + bool progress = vectorize_block(&b, nir_start_block(impl), instr_set,
> + input_vars, output_vars);
> +
> + if (progress)
> + nir_metadata_preserve(impl, nir_metadata_block_index |
> + nir_metadata_dominance);
>
Two lines. Please use { }.
> +
> + vec_instr_set_destroy(instr_set);
> + return false;
> +}
> +
> +bool
> +nir_opt_vectorize_io(nir_shader *shader, bool skip_fs_inputs)
> +{
> + bool progress = false;
> +
> + if (skip_fs_inputs && shader->info.stage == MESA_SHADER_FRAGMENT)
> + return false;
> +
> + nir_foreach_function(function, shader) {
> + if (function->impl)
> + progress |= nir_opt_vectorize_io_impl(function->impl);
> + }
> +
> + return progress;
> +}
> --
> 2.19.1
>
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>
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