[Mesa-dev] [PATCH v3 022/104] nir: Support deref instructions in lower_indirect_derefs
Jason Ekstrand
jason at jlekstrand.net
Tue Apr 3 18:32:49 UTC 2018
---
src/compiler/nir/nir_lower_indirect_derefs.c | 156 +++++++++++++++++++++++++++
1 file changed, 156 insertions(+)
diff --git a/src/compiler/nir/nir_lower_indirect_derefs.c b/src/compiler/nir/nir_lower_indirect_derefs.c
index 02f202d..ebeb79b 100644
--- a/src/compiler/nir/nir_lower_indirect_derefs.c
+++ b/src/compiler/nir/nir_lower_indirect_derefs.c
@@ -23,6 +23,7 @@
#include "nir.h"
#include "nir_builder.h"
+#include "nir_deref.h"
static void
emit_load_store(nir_builder *b, nir_intrinsic_instr *orig_instr,
@@ -184,6 +185,160 @@ lower_indirect_block(nir_block *block, nir_builder *b,
return progress;
}
+static void
+emit_load_store_deref(nir_builder *b, nir_intrinsic_instr *orig_instr,
+ nir_deref_instr *parent,
+ nir_deref_instr **deref_arr,
+ nir_ssa_def **dest, nir_ssa_def *src);
+
+static void
+emit_indirect_load_store_deref(nir_builder *b, nir_intrinsic_instr *orig_instr,
+ nir_deref_instr *parent,
+ nir_deref_instr **deref_arr,
+ int start, int end,
+ nir_ssa_def **dest, nir_ssa_def *src)
+{
+ assert(start < end);
+ if (start == end - 1) {
+ nir_ssa_def *index = nir_imm_int(b, start);
+ emit_load_store_deref(b, orig_instr,
+ nir_build_deref_array(b, parent, index),
+ deref_arr + 1, dest, src);
+ } else {
+ int mid = start + (end - start) / 2;
+
+ nir_ssa_def *then_dest, *else_dest;
+
+ nir_deref_instr *deref = *deref_arr;
+ assert(deref->deref_type == nir_deref_type_array);
+
+ nir_push_if(b, nir_ilt(b, deref->arr.index.ssa, nir_imm_int(b, mid)));
+ emit_indirect_load_store_deref(b, orig_instr, parent, deref_arr,
+ start, mid, &then_dest, src);
+ nir_push_else(b, NULL);
+ emit_indirect_load_store_deref(b, orig_instr, parent, deref_arr,
+ mid, end, &else_dest, src);
+ nir_pop_if(b, NULL);
+
+ if (src == NULL)
+ *dest = nir_if_phi(b, then_dest, else_dest);
+ }
+}
+
+static void
+emit_load_store_deref(nir_builder *b, nir_intrinsic_instr *orig_instr,
+ nir_deref_instr *parent,
+ nir_deref_instr **deref_arr,
+ nir_ssa_def **dest, nir_ssa_def *src)
+{
+ for (; *deref_arr; deref_arr++) {
+ nir_deref_instr *deref = *deref_arr;
+ if (deref->deref_type == nir_deref_type_array &&
+ nir_src_as_const_value(deref->arr.index) == NULL) {
+ int length = glsl_get_length(parent->type);
+
+ emit_indirect_load_store_deref(b, orig_instr, parent, deref_arr,
+ 0, length, dest, src);
+ return;
+ }
+
+ parent = nir_build_deref_follower(b, parent, deref);
+ }
+
+ /* We reached the end of the deref chain. Emit the instruction */
+ assert(*deref_arr == NULL);
+
+ if (src == NULL) {
+ /* This is a load instruction */
+ nir_intrinsic_instr *load =
+ nir_intrinsic_instr_create(b->shader, orig_instr->intrinsic);
+ load->num_components = orig_instr->num_components;
+
+ load->src[0] = nir_src_for_ssa(&parent->dest.ssa);
+
+ /* Copy over any other sources. This is needed for interp_deref_at */
+ for (unsigned i = 1;
+ i < nir_intrinsic_infos[orig_instr->intrinsic].num_srcs; i++)
+ nir_src_copy(&load->src[i], &orig_instr->src[i], load);
+
+ nir_ssa_dest_init(&load->instr, &load->dest,
+ orig_instr->dest.ssa.num_components,
+ orig_instr->dest.ssa.bit_size, NULL);
+ nir_builder_instr_insert(b, &load->instr);
+ *dest = &load->dest.ssa;
+ } else {
+ assert(orig_instr->intrinsic == nir_intrinsic_store_deref);
+ nir_store_deref(b, parent, src, nir_intrinsic_write_mask(orig_instr));
+ }
+}
+
+static bool
+lower_indirect_derefs_block(nir_block *block, nir_builder *b,
+ nir_variable_mode modes)
+{
+ bool progress = false;
+
+ nir_foreach_instr_safe(instr, block) {
+ if (instr->type != nir_instr_type_intrinsic)
+ continue;
+
+ nir_intrinsic_instr *intrin = nir_instr_as_intrinsic(instr);
+ if (intrin->intrinsic != nir_intrinsic_load_deref &&
+ intrin->intrinsic != nir_intrinsic_interp_deref_at_centroid &&
+ intrin->intrinsic != nir_intrinsic_interp_deref_at_sample &&
+ intrin->intrinsic != nir_intrinsic_interp_deref_at_offset &&
+ intrin->intrinsic != nir_intrinsic_store_deref)
+ continue;
+
+ nir_deref_instr *deref =
+ nir_instr_as_deref(intrin->src[0].ssa->parent_instr);
+
+ /* Walk the deref chain back to the base and look for indirects */
+ bool has_indirect = false;
+ nir_deref_instr *base = deref;
+ while (base->deref_type != nir_deref_type_var) {
+ if (base->deref_type == nir_deref_type_array &&
+ nir_src_as_const_value(base->arr.index) == NULL)
+ has_indirect = true;
+
+ base = nir_instr_as_deref(base->parent.ssa->parent_instr);
+ }
+
+ if (!has_indirect)
+ continue;
+
+ /* Only lower variables whose mode is in the mask, or compact
+ * array variables. (We can't handle indirects on tightly packed
+ * scalar arrays, so we need to lower them regardless.)
+ */
+ if (!(modes & base->var->data.mode) && !base->var->data.compact)
+ continue;
+
+ b->cursor = nir_instr_remove(&intrin->instr);
+
+ struct nir_deref_path path;
+ nir_deref_path_init(&path, deref, NULL);
+ assert(path.path[0] == base);
+
+ if (intrin->intrinsic == nir_intrinsic_store_deref) {
+ assert(intrin->src[1].is_ssa);
+ emit_load_store_deref(b, intrin, base, &path.path[1],
+ NULL, intrin->src[1].ssa);
+ } else {
+ nir_ssa_def *result;
+ emit_load_store_deref(b, intrin, base, &path.path[1],
+ &result, NULL);
+ nir_ssa_def_rewrite_uses(&intrin->dest.ssa, nir_src_for_ssa(result));
+ }
+
+ nir_deref_path_finish(&path);
+
+ progress = true;
+ }
+
+ return progress;
+}
+
static bool
lower_indirects_impl(nir_function_impl *impl, nir_variable_mode modes)
{
@@ -193,6 +348,7 @@ lower_indirects_impl(nir_function_impl *impl, nir_variable_mode modes)
nir_foreach_block_safe(block, impl) {
progress |= lower_indirect_block(block, &builder, modes);
+ progress |= lower_indirect_derefs_block(block, &builder, modes);
}
if (progress)
--
2.5.0.400.gff86faf
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