[Mesa-dev] [RFC 3/4] nir: support indirect indexing samplers in struct arrays
Jason Ekstrand
jason at jlekstrand.net
Sun Aug 30 08:27:57 PDT 2015
On Aug 30, 2015 3:44 AM, "Timothy Arceri" <t_arceri at yahoo.com.au> wrote:
>
> As a bonus we get indirect support for arrays of arrays for free.
> ---
> I've marked this as request for comment as although it works enough for
to
> pass all the piglit tests there are issues as I'm still trying to figure
out
> nir.
>
> The issues are around the second call to nir_instr_move_src() this call
> expects the use_link list not to be empty just so it can then remove all
> entries so I add the list_addtail() call above it to work around this.
> While this is enough to pass the piglit tests on a non debug build it
fails
> validation for debug builds.
>
> I'm clearly missing a step and would be greatful to anyone who can point
me
> in the right direction.
nir_instr_move_src expects the source to be already in an instruction. The
reason its correct in the old code is because were stealing it from the
indirect. For adding a "new" nir_src, use nir_instr_rewrite_src.
--Jason
> The validation error:
> nir/nir_validate.c:873: postvalidate_ssa_def: Assertion `entry' failed.
>
> src/glsl/nir/nir_lower_samplers.cpp | 169
++++++++++++++++++++----------------
> 1 file changed, 95 insertions(+), 74 deletions(-)
>
> diff --git a/src/glsl/nir/nir_lower_samplers.cpp
b/src/glsl/nir/nir_lower_samplers.cpp
> index 9583b45..dbe9e95 100644
> --- a/src/glsl/nir/nir_lower_samplers.cpp
> +++ b/src/glsl/nir/nir_lower_samplers.cpp
> @@ -24,6 +24,7 @@
> */
>
> #include "nir.h"
> +#include "nir_builder.h"
> #include "../program.h"
> #include "program/hash_table.h"
> #include "ir_uniform.h"
> @@ -35,89 +36,49 @@ extern "C" {
> #include "program/program.h"
> }
>
> -static unsigned
> -get_sampler_index(const struct gl_shader_program *shader_program,
> - gl_shader_stage stage, const char *name)
> -{
> - unsigned location;
> - if (!shader_program->UniformHash->get(location, name)) {
> - assert(!"failed to find sampler");
> - return 0;
> - }
> -
> - if (!shader_program->UniformStorage[location].sampler[stage].active) {
> - assert(!"cannot return a sampler");
> - return 0;
> - }
> -
> - return shader_program->UniformStorage[location].sampler[stage].index;
> -}
> -
> +/* Calculate the sampler index based on array indicies and also
> + * calculate the base uniform location for struct members.
> + */
> static void
> -lower_sampler(nir_tex_instr *instr, const struct gl_shader_program
*shader_program,
> - gl_shader_stage stage, void *mem_ctx)
> +calc_sampler_offsets(nir_deref *tail, nir_tex_instr *instr,
> + unsigned *array_elements, nir_src *indirect,
> + nir_builder *b, unsigned *location,
> + bool *found_indirect)
> {
> - if (instr->sampler == NULL)
> - return;
> -
> - /* Get the name and the offset */
> - instr->sampler_index = 0;
> - char *name = ralloc_strdup(mem_ctx, instr->sampler->var->name);
> -
> - for (nir_deref *deref = &instr->sampler->deref;
> - deref->child; deref = deref->child) {
> - switch (deref->child->deref_type) {
> + if (tail->child != NULL) {
> + switch (tail->child->deref_type) {
> case nir_deref_type_array: {
> - nir_deref_array *deref_array = nir_deref_as_array(deref->child);
> + nir_deref_array *deref_array = nir_deref_as_array(tail->child);
>
> assert(deref_array->deref_array_type !=
nir_deref_array_type_wildcard);
>
> - if (deref_array->deref.child) {
> - ralloc_asprintf_append(&name, "[%u]",
> - deref_array->deref_array_type ==
nir_deref_array_type_direct ?
> - deref_array->base_offset : 0);
> - } else {
> - assert(deref->child->type->base_type == GLSL_TYPE_SAMPLER);
> - instr->sampler_index = deref_array->base_offset;
> - }
> + calc_sampler_offsets(tail->child, instr, array_elements,
> + indirect, b, location, found_indirect);
> + instr->sampler_index += deref_array->base_offset *
*array_elements;
>
> - /* XXX: We're assuming here that the indirect is the last array
> - * thing we have. This should be ok for now as we don't support
> - * arrays_of_arrays yet.
> - */
> if (deref_array->deref_array_type ==
nir_deref_array_type_indirect) {
> - /* First, we have to resize the array of texture sources */
> - nir_tex_src *new_srcs = rzalloc_array(instr, nir_tex_src,
> - instr->num_srcs + 1);
> -
> - for (unsigned i = 0; i < instr->num_srcs; i++) {
> - new_srcs[i].src_type = instr->src[i].src_type;
> - nir_instr_move_src(&instr->instr, &new_srcs[i].src,
> - &instr->src[i].src);
> + nir_ssa_def *mul =
> + nir_imul(b, nir_imm_int(b, *array_elements),
> + nir_ssa_for_src(b, deref_array->indirect, 1));
> +
> + if (*found_indirect) {
> + indirect->ssa =
> + nir_iadd(b, nir_ssa_for_src(b, *indirect, 1), mul);
> + } else {
> + *indirect = nir_src_for_ssa(mul);
> + *found_indirect = true;
> }
> -
> - ralloc_free(instr->src);
> - instr->src = new_srcs;
> -
> - /* Now we can go ahead and move the source over to being a
> - * first-class texture source.
> - */
> - instr->src[instr->num_srcs].src_type =
nir_tex_src_sampler_offset;
> - instr->num_srcs++;
> - nir_instr_move_src(&instr->instr,
> - &instr->src[instr->num_srcs - 1].src,
> - &deref_array->indirect);
> -
> - instr->sampler_array_size = glsl_get_length(deref->type);
> }
> - break;
> +
> + *array_elements *= glsl_get_length(tail->type);
> + break;
> }
>
> case nir_deref_type_struct: {
> - nir_deref_struct *deref_struct =
nir_deref_as_struct(deref->child);
> - const char *field = glsl_get_struct_elem_name(deref->type,
> -
deref_struct->index);
> - ralloc_asprintf_append(&name, ".%s", field);
> + nir_deref_struct *deref_struct =
nir_deref_as_struct(tail->child);
> + *location += deref_struct->index;
> + calc_sampler_offsets(tail->child, instr, array_elements,
> + indirect, b, location, found_indirect);
> break;
> }
>
> @@ -125,15 +86,75 @@ lower_sampler(nir_tex_instr *instr, const struct
gl_shader_program *shader_progr
> unreachable("Invalid deref type");
> break;
> }
> + } else {
> + return;
> + }
> +}
> +
> +static void
> +lower_sampler(nir_tex_instr *instr, const struct gl_shader_program
*shader_program,
> + gl_shader_stage stage, nir_builder *builder)
> +{
> + if (instr->sampler == NULL)
> + return;
> +
> + instr->sampler_index = 0;
> + unsigned location = instr->sampler->var->data.location;
> +
> + if (instr->sampler->deref.child) {
> + unsigned array_elements = 1;
> + nir_src indirect;
> + bool found_indirect = false;
> +
> + builder->cursor = nir_before_instr(&instr->instr);
> + calc_sampler_offsets(&instr->sampler->deref, instr,
> + &array_elements, &indirect, builder,
> + &location, &found_indirect);
> +
> + if (found_indirect) {
> + /* First, we have to resize the array of texture sources */
> + nir_tex_src *new_srcs = rzalloc_array(instr, nir_tex_src,
> + instr->num_srcs + 1);
> +
> + for (unsigned i = 0; i < instr->num_srcs; i++) {
> + new_srcs[i].src_type = instr->src[i].src_type;
> + nir_instr_move_src(&instr->instr, &new_srcs[i].src,
> + &instr->src[i].src);
> + }
> +
> + ralloc_free(instr->src);
> + instr->src = new_srcs;
> +
> + /* Now we can go ahead and move the source over to being a
> + * first-class texture source.
> + */
> + nir_src indirect_nir_src = nir_src_for_ssa(indirect.ssa);
> + list_addtail(&indirect_nir_src.use_link,
&indirect_nir_src.ssa->uses);
> +
> + instr->src[instr->num_srcs].src_type =
nir_tex_src_sampler_offset;
> + instr->num_srcs++;
> + nir_instr_move_src(&instr->instr,
> + &instr->src[instr->num_srcs - 1].src,
> + &indirect_nir_src);
> +
> + instr->sampler_array_size = array_elements;
> + }
> + }
> +
> + if (location > shader_program->NumUniformStorage - 1 ||
> + !shader_program->UniformStorage[location].sampler[stage].active) {
> + assert(!"cannot return a sampler");
> + return;
> }
>
> - instr->sampler_index += get_sampler_index(shader_program, stage,
name);
> + instr->sampler_index +=
> + shader_program->UniformStorage[location].sampler[stage].index;
>
> instr->sampler = NULL;
> }
>
> typedef struct {
> - void *mem_ctx;
> + nir_builder builder;
> const struct gl_shader_program *shader_program;
> gl_shader_stage stage;
> } lower_state;
> @@ -147,7 +168,7 @@ lower_block_cb(nir_block *block, void *_state)
> if (instr->type == nir_instr_type_tex) {
> nir_tex_instr *tex_instr = nir_instr_as_tex(instr);
> lower_sampler(tex_instr, state->shader_program, state->stage,
> - state->mem_ctx);
> + &state->builder);
> }
> }
>
> @@ -160,7 +181,7 @@ lower_impl(nir_function_impl *impl, const struct
gl_shader_program *shader_progr
> {
> lower_state state;
>
> - state.mem_ctx = ralloc_parent(impl);
> + nir_builder_init(&state.builder, impl);
> state.shader_program = shader_program;
> state.stage = stage;
>
> --
> 2.4.3
>
> _______________________________________________
> mesa-dev mailing list
> mesa-dev at lists.freedesktop.org
> http://lists.freedesktop.org/mailman/listinfo/mesa-dev
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