[Mesa-dev] [PATCH 15/16] mesa/st: add nir pass for lowering builtin uniforms
Rob Clark
robdclark at gmail.com
Sat Apr 2 17:38:38 UTC 2016
On Fri, Apr 1, 2016 at 2:23 PM, Jason Ekstrand <jason at jlekstrand.net> wrote:
>
>
> On Sat, Mar 26, 2016 at 2:02 PM, Rob Clark <robdclark at gmail.com> wrote:
>>
>> From: Rob Clark <robclark at freedesktop.org>
>>
>> Signed-off-by: Rob Clark <robclark at freedesktop.org>
>> ---
>> src/mesa/Makefile.sources | 2 +
>> src/mesa/state_tracker/st_nir.h | 28 +++
>> src/mesa/state_tracker/st_nir_lower_builtin.c | 242
>> ++++++++++++++++++++++++++
>> 3 files changed, 272 insertions(+)
>> create mode 100644 src/mesa/state_tracker/st_nir.h
>> create mode 100644 src/mesa/state_tracker/st_nir_lower_builtin.c
>>
>> diff --git a/src/mesa/Makefile.sources b/src/mesa/Makefile.sources
>> index 7b5b6ea..6c93d07 100644
>> --- a/src/mesa/Makefile.sources
>> +++ b/src/mesa/Makefile.sources
>> @@ -495,6 +495,8 @@ STATETRACKER_FILES = \
>> state_tracker/st_manager.h \
>> state_tracker/st_mesa_to_tgsi.c \
>> state_tracker/st_mesa_to_tgsi.h \
>> + state_tracker/st_nir.h \
>> + state_tracker/st_nir_lower_builtin.c \
>> state_tracker/st_program.c \
>> state_tracker/st_program.h \
>> state_tracker/st_texture.c \
>> diff --git a/src/mesa/state_tracker/st_nir.h
>> b/src/mesa/state_tracker/st_nir.h
>> new file mode 100644
>> index 0000000..1c07c4c
>> --- /dev/null
>> +++ b/src/mesa/state_tracker/st_nir.h
>> @@ -0,0 +1,28 @@
>> +/*
>> + * Copyright © 2016 Red Hat
>> + *
>> + * 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.
>> + */
>> +
>> +#pragma once
>> +
>> +typedef struct nir_shader nir_shader;
>> +
>> +void st_nir_lower_builtin(nir_shader *shader);
>> diff --git a/src/mesa/state_tracker/st_nir_lower_builtin.c
>> b/src/mesa/state_tracker/st_nir_lower_builtin.c
>> new file mode 100644
>> index 0000000..7f3262f
>> --- /dev/null
>> +++ b/src/mesa/state_tracker/st_nir_lower_builtin.c
>> @@ -0,0 +1,242 @@
>> +/*
>> + * Copyright © 2016 Red Hat
>> + *
>> + * 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.
>> + */
>> +
>> +/* Lowering pass that lowers accesses to built-in uniform variables.
>> + * Built-in uniforms are not necessarily packed the same way that
>> + * normal uniform structs are, for example:
>> + *
>> + * struct gl_FogParameters {
>> + * vec4 color;
>> + * float density;
>> + * float start;
>> + * float end;
>> + * float scale;
>> + * };
>> + *
>> + * is packed into vec4[2], whereas the same struct would be packed
>> + * (by gallium), as vec4[5] if it where not built-in. Because of
>> + * this, we need to replace (for example) access like:
>> + *
>> + * vec1 ssa_1 = intrinsic load_var () (gl_Fog.start) ()
>> + *
>> + * with:
>> + *
>> + * vec4 ssa_2 = intrinsic load_var () (fog.params) ()
>> + * vec1 ssa_1 = ssa_2.y
>> + *
>> + * with appropriate substitutions in the uniform variables list:
>> + *
>> + * decl_var uniform INTERP_QUALIFIER_NONE gl_FogParameters gl_Fog (0,
>> 0)
>> + *
>> + * would become:
>> + *
>> + * decl_var uniform INTERP_QUALIFIER_NONE vec4 state.fog.color (0, 0)
>> + * decl_var uniform INTERP_QUALIFIER_NONE vec4 state.fog.params (0, 1)
>> + *
>> + * See in particular 'struct gl_builtin_uniform_element'.
>> + */
>> +
>> +#include "compiler/nir/nir.h"
>> +#include "compiler/nir/nir_builder.h"
>> +#include "st_nir.h"
>> +#include "compiler/glsl/ir.h"
>> +#include "uniforms.h"
>> +#include "program/prog_instruction.h"
>> +
>> +typedef struct {
>> + nir_shader *shader;
>> + nir_builder builder;
>> + void *mem_ctx;
>> +} lower_builtin_state;
>> +
>> +static const struct gl_builtin_uniform_element *
>> +get_element(const struct gl_builtin_uniform_desc *desc, nir_deref_var
>> *deref)
>> +{
>> + nir_deref *tail = &deref->deref;
>> +
>> + if ((desc->num_elements == 1) && (desc->elements[0].field == NULL))
>> + return NULL;
>> +
>> + /* we handle array's in get_variable(): */
>> + if (tail->child->deref_type == nir_deref_type_array)
>> + tail = tail->child;
>> +
>> + /* don't need to deal w/ non-struct or array of non-struct: */
>> + if (!tail->child)
>> + return NULL;
>> +
>> + if (tail->child->deref_type != nir_deref_type_struct)
>> + return NULL;
>> +
>> + nir_deref_struct *deref_struct = nir_deref_as_struct(tail->child);
>> +
>> + assert(deref_struct->index < desc->num_elements);
>> +
>> + return &desc->elements[deref_struct->index];
>> +}
>> +
>> +static nir_variable *
>> +get_variable(lower_builtin_state *state, nir_deref_var *deref,
>> + const struct gl_builtin_uniform_element *element)
>> +{
>> + nir_shader *shader = state->shader;
>> + int tokens[STATE_LENGTH];
>> +
>> + memcpy(tokens, element->tokens, sizeof(tokens));
>> +
>> + if (deref->deref.child->deref_type == nir_deref_type_array) {
>> + nir_deref_array *darr = nir_deref_as_array(deref->deref.child);
>> +
>> + assert(darr->deref_array_type == nir_deref_array_type_direct);
>> +
>> + /* we need to fixup the array index slot: */
>> + switch (tokens[0]) {
>> + case STATE_MODELVIEW_MATRIX:
>> + case STATE_PROJECTION_MATRIX:
>> + case STATE_MVP_MATRIX:
>> + case STATE_TEXTURE_MATRIX:
>> + case STATE_PROGRAM_MATRIX:
>> + case STATE_LIGHT:
>> + case STATE_LIGHTPROD:
>> + case STATE_TEXGEN:
>> + case STATE_TEXENV_COLOR:
>> + case STATE_CLIPPLANE:
>> + tokens[1] = darr->base_offset;
>> + break;
>> + }
>> + }
>> +
>> + char *name = _mesa_program_state_string((gl_state_index *)tokens);
>> +
>> + nir_foreach_variable(var, &shader->uniforms)
>> + if (strcmp(var->name, name) == 0)
>> + return var;
>> +
>> + /* variable doesn't exist yet, so create it: */
>> + nir_variable *var =
>> + nir_variable_create(shader, nir_var_uniform, glsl_vec4_type(),
>> name);
>> +
>> + var->num_state_slots = 1;
>> + var->state_slots = ralloc_array(var, nir_state_slot, 1);
>> + memcpy(var->state_slots[0].tokens, tokens,
>> + sizeof(var->state_slots[0].tokens));
>> +
>> + free(name);
>> +
>> + return var;
>> +}
>> +
>> +static bool
>> +lower_builtin_block(nir_block *block, void *_state)
>> +{
>> + lower_builtin_state *state = _state;
>> +
>> + nir_builder *b = &state->builder;
>> +
>> + nir_foreach_instr_safe(block, instr) {
>> + if (instr->type != nir_instr_type_intrinsic)
>> + continue;
>> +
>> + nir_intrinsic_instr *intrin = nir_instr_as_intrinsic(instr);
>> +
>> + if (intrin->intrinsic != nir_intrinsic_load_var)
>> + continue;
>> +
>> + nir_variable *var = intrin->variables[0]->var;
>> + if (var->data.mode != nir_var_uniform)
>> + continue;
>> +
>> + /* built-in's will always start with "gl_" */
>> + if (strncmp(var->name, "gl_", 3) != 0)
>> + continue;
>> +
>> + const struct gl_builtin_uniform_desc *desc =
>> + _mesa_glsl_get_builtin_uniform_desc(var->name);
>> +
>> + /* if no descriptor, it isn't something we need to handle
>> specially: */
>> + if (!desc)
>> + continue;
>> +
>> + const struct gl_builtin_uniform_element *element =
>> + get_element(desc, intrin->variables[0]);
>> +
>> + /* matrix elements (array_deref) do not need special handling: */
>> + if (!element)
>> + continue;
>> +
>> + /* remove existing var from uniform list: */
>> + exec_node_remove(&var->node);
>> + exec_node_self_link(&var->node); /* no delinit() :-( */
>
>
> Are you sure you want to remove it multiple times? There can be more than
> one load_var for a particular uniform. I guess since you self_link, it's
> safe to do so. Maybe throw in a comment?
Yup, that is kinda the purpose of the _self_link().. I'll add a comment..
> Other than that, this looks mostly ok to me. I can't really say that I know
> enough to properly review it though.
I'm a bit curious how the built-in uniforms work on i965..
_mesa_builtin_uniform_desc[] seems to be used from core mesa (not just
mesa/st) so I assume that builtin-uniforms get packed according to
'struct gl_builtin_uniform_element' as well?
BR,
-R
>>
>> +
>> + nir_variable *new_var =
>> + get_variable(state, intrin->variables[0], element);
>> +
>> + b->cursor = nir_before_instr(instr);
>> +
>> + nir_ssa_def *def = nir_load_var(b, new_var);
>> +
>> + /* swizzle the result: */
>> + unsigned swiz[4];
>> + for (unsigned i = 0; i < 4; i++) {
>> + swiz[i] = GET_SWZ(element->swizzle, i);
>> + assert(swiz[i] <= SWIZZLE_W);
>> + }
>> + def = nir_swizzle(b, def, swiz, intrin->num_components, true);
>> +
>> + /* and rewrite uses of original instruction: */
>> + assert(intrin->dest.is_ssa);
>> + nir_ssa_def_rewrite_uses(&intrin->dest.ssa, nir_src_for_ssa(def));
>> +
>> + /* at this point intrin should be unused. We need to remove it
>> + * (rather than waiting for DCE pass) to avoid dangling reference
>> + * to remove'd var. And we have to remove the original uniform
>> + * var since we don't want it to get uniform space allocated.
>> + */
>> + exec_node_remove(&intrin->instr.node);
>> + }
>> +
>> + return true;
>> +}
>> +
>> +static void
>> +lower_builtin_impl(lower_builtin_state *state, nir_function_impl *impl)
>> +{
>> + nir_builder_init(&state->builder, impl);
>> + state->mem_ctx = ralloc_parent(impl);
>> +
>> + nir_foreach_block(impl, lower_builtin_block, state);
>> +
>> + nir_metadata_preserve(impl, nir_metadata_block_index |
>> + nir_metadata_dominance);
>> +}
>> +
>> +void
>> +st_nir_lower_builtin(nir_shader *shader)
>> +{
>> + lower_builtin_state state;
>> + state.shader = shader;
>> + nir_foreach_function(shader, function) {
>> + if (function->impl)
>> + lower_builtin_impl(&state, function->impl);
>> + }
>> +}
>> --
>> 2.5.5
>>
>> _______________________________________________
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>> mesa-dev at lists.freedesktop.org
>> https://lists.freedesktop.org/mailman/listinfo/mesa-dev
>
>
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