[Mesa-dev] [RFC 3/4] nir: support indirect indexing samplers in struct arrays
Timothy Arceri
t_arceri at yahoo.com.au
Sun Aug 30 03:44:26 PDT 2015
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.
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
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