1 files changed, 350 insertions, 0 deletions

diff --git a/src/compiler/nir/nir_lower_io.c b/src/compiler/nir/nir_lower_io.c
new file mode 100644
index 00000000000..80c5151f0ea
--- /dev/null
+++ b/src/compiler/nir/nir_lower_io.c
@@ -0,0 +1,350 @@
+/*
+ * Copyright © 2014 Intel Corporation
+ *
+ * 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.
+ *
+ * Authors:
+ *    Connor Abbott ([email protected])
+ *    Jason Ekstrand ([email protected])
+ *
+ */
+
+/*
+ * This lowering pass converts references to input/output variables with
+ * loads/stores to actual input/output intrinsics.
+ */
+
+#include "nir.h"
+#include "nir_builder.h"
+
+struct lower_io_state {
+   nir_builder builder;
+   void *mem_ctx;
+   int (*type_size)(const struct glsl_type *type);
+   nir_variable_mode mode;
+};
+
+void
+nir_assign_var_locations(struct exec_list *var_list, unsigned *size,
+                         int (*type_size)(const struct glsl_type *))
+{
+   unsigned location = 0;
+
+   nir_foreach_variable(var, var_list) {
+      /*
+       * UBO's have their own address spaces, so don't count them towards the
+       * number of global uniforms
+       */
+      if ((var->data.mode == nir_var_uniform || var->data.mode == nir_var_shader_storage) &&
+          var->interface_type != NULL)
+         continue;
+
+      var->data.driver_location = location;
+      location += type_size(var->type);
+   }
+
+   *size = location;
+}
+
+/**
+ * Returns true if we're processing a stage whose inputs are arrays indexed
+ * by a vertex number (such as geometry shader inputs).
+ */
+static bool
+is_per_vertex_input(struct lower_io_state *state, nir_variable *var)
+{
+   gl_shader_stage stage = state->builder.shader->stage;
+
+   return var->data.mode == nir_var_shader_in && !var->data.patch &&
+          (stage == MESA_SHADER_TESS_CTRL ||
+           stage == MESA_SHADER_TESS_EVAL ||
+           stage == MESA_SHADER_GEOMETRY);
+}
+
+static bool
+is_per_vertex_output(struct lower_io_state *state, nir_variable *var)
+{
+   gl_shader_stage stage = state->builder.shader->stage;
+   return var->data.mode == nir_var_shader_out && !var->data.patch &&
+          stage == MESA_SHADER_TESS_CTRL;
+}
+
+static nir_ssa_def *
+get_io_offset(nir_builder *b, nir_deref_var *deref,
+              nir_ssa_def **vertex_index,
+              int (*type_size)(const struct glsl_type *))
+{
+   nir_deref *tail = &deref->deref;
+
+   /* For per-vertex input arrays (i.e. geometry shader inputs), keep the
+    * outermost array index separate.  Process the rest normally.
+    */
+   if (vertex_index != NULL) {
+      tail = tail->child;
+      assert(tail->deref_type == nir_deref_type_array);
+      nir_deref_array *deref_array = nir_deref_as_array(tail);
+
+      nir_ssa_def *vtx = nir_imm_int(b, deref_array->base_offset);
+      if (deref_array->deref_array_type == nir_deref_array_type_indirect) {
+         vtx = nir_iadd(b, vtx, nir_ssa_for_src(b, deref_array->indirect, 1));
+      }
+      *vertex_index = vtx;
+   }
+
+   /* Just emit code and let constant-folding go to town */
+   nir_ssa_def *offset = nir_imm_int(b, 0);
+
+   while (tail->child != NULL) {
+      const struct glsl_type *parent_type = tail->type;
+      tail = tail->child;
+
+      if (tail->deref_type == nir_deref_type_array) {
+         nir_deref_array *deref_array = nir_deref_as_array(tail);
+         unsigned size = type_size(tail->type);
+
+         offset = nir_iadd(b, offset,
+                           nir_imm_int(b, size * deref_array->base_offset));
+
+         if (deref_array->deref_array_type == nir_deref_array_type_indirect) {
+            nir_ssa_def *mul =
+               nir_imul(b, nir_imm_int(b, size),
+                        nir_ssa_for_src(b, deref_array->indirect, 1));
+
+            offset = nir_iadd(b, offset, mul);
+         }
+      } else if (tail->deref_type == nir_deref_type_struct) {
+         nir_deref_struct *deref_struct = nir_deref_as_struct(tail);
+
+         unsigned field_offset = 0;
+         for (unsigned i = 0; i < deref_struct->index; i++) {
+            field_offset += type_size(glsl_get_struct_field(parent_type, i));
+         }
+         offset = nir_iadd(b, offset, nir_imm_int(b, field_offset));
+      }
+   }
+
+   return offset;
+}
+
+static nir_intrinsic_op
+load_op(struct lower_io_state *state,
+        nir_variable_mode mode, bool per_vertex)
+{
+   nir_intrinsic_op op;
+   switch (mode) {
+   case nir_var_shader_in:
+      op = per_vertex ? nir_intrinsic_load_per_vertex_input :
+                        nir_intrinsic_load_input;
+      break;
+   case nir_var_shader_out:
+      op = per_vertex ? nir_intrinsic_load_per_vertex_output :
+                        nir_intrinsic_load_output;
+      break;
+   case nir_var_uniform:
+      op = nir_intrinsic_load_uniform;
+      break;
+   default:
+      unreachable("Unknown variable mode");
+   }
+   return op;
+}
+
+static bool
+nir_lower_io_block(nir_block *block, void *void_state)
+{
+   struct lower_io_state *state = void_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 &&
+          intrin->intrinsic != nir_intrinsic_store_var)
+         continue;
+
+      nir_variable_mode mode = intrin->variables[0]->var->data.mode;
+
+      if (state->mode != nir_var_all && state->mode != mode)
+         continue;
+
+      if (mode != nir_var_shader_in &&
+          mode != nir_var_shader_out &&
+          mode != nir_var_uniform)
+         continue;
+
+      b->cursor = nir_before_instr(instr);
+
+      switch (intrin->intrinsic) {
+      case nir_intrinsic_load_var: {
+         bool per_vertex =
+            is_per_vertex_input(state, intrin->variables[0]->var) ||
+            is_per_vertex_output(state, intrin->variables[0]->var);
+
+         nir_ssa_def *offset;
+         nir_ssa_def *vertex_index;
+
+         offset = get_io_offset(b, intrin->variables[0],
+                                per_vertex ? &vertex_index : NULL,
+                                state->type_size);
+
+         nir_intrinsic_instr *load =
+            nir_intrinsic_instr_create(state->mem_ctx,
+                                       load_op(state, mode, per_vertex));
+         load->num_components = intrin->num_components;
+
+         load->const_index[0] =
+            intrin->variables[0]->var->data.driver_location;
+
+         if (per_vertex)
+            load->src[0] = nir_src_for_ssa(vertex_index);
+
+         load->src[per_vertex ? 1 : 0] = nir_src_for_ssa(offset);
+
+         if (intrin->dest.is_ssa) {
+            nir_ssa_dest_init(&load->instr, &load->dest,
+                              intrin->num_components, NULL);
+            nir_ssa_def_rewrite_uses(&intrin->dest.ssa,
+                                     nir_src_for_ssa(&load->dest.ssa));
+         } else {
+            nir_dest_copy(&load->dest, &intrin->dest, state->mem_ctx);
+         }
+
+         nir_instr_insert_before(&intrin->instr, &load->instr);
+         nir_instr_remove(&intrin->instr);
+         break;
+      }
+
+      case nir_intrinsic_store_var: {
+         assert(mode == nir_var_shader_out);
+
+         nir_ssa_def *offset;
+         nir_ssa_def *vertex_index;
+
+         bool per_vertex =
+            is_per_vertex_output(state, intrin->variables[0]->var);
+
+         offset = get_io_offset(b, intrin->variables[0],
+                                per_vertex ? &vertex_index : NULL,
+                                state->type_size);
+
+         nir_intrinsic_op store_op =
+            per_vertex ? nir_intrinsic_store_per_vertex_output :
+                         nir_intrinsic_store_output;
+
+         nir_intrinsic_instr *store = nir_intrinsic_instr_create(state->mem_ctx,
+                                                                 store_op);
+         store->num_components = intrin->num_components;
+
+         nir_src_copy(&store->src[0], &intrin->src[0], store);
+
+         store->const_index[0] =
+            intrin->variables[0]->var->data.driver_location;
+
+         /* Copy the writemask */
+         store->const_index[1] = intrin->const_index[0];
+
+         if (per_vertex)
+            store->src[1] = nir_src_for_ssa(vertex_index);
+
+         store->src[per_vertex ? 2 : 1] = nir_src_for_ssa(offset);
+
+         nir_instr_insert_before(&intrin->instr, &store->instr);
+         nir_instr_remove(&intrin->instr);
+         break;
+      }
+
+      default:
+         break;
+      }
+   }
+
+   return true;
+}
+
+static void
+nir_lower_io_impl(nir_function_impl *impl,
+                  nir_variable_mode mode,
+                  int (*type_size)(const struct glsl_type *))
+{
+   struct lower_io_state state;
+
+   nir_builder_init(&state.builder, impl);
+   state.mem_ctx = ralloc_parent(impl);
+   state.mode = mode;
+   state.type_size = type_size;
+
+   nir_foreach_block(impl, nir_lower_io_block, &state);
+
+   nir_metadata_preserve(impl, nir_metadata_block_index |
+                               nir_metadata_dominance);
+}
+
+void
+nir_lower_io(nir_shader *shader, nir_variable_mode mode,
+             int (*type_size)(const struct glsl_type *))
+{
+   nir_foreach_function(shader, function) {
+      if (function->impl)
+         nir_lower_io_impl(function->impl, mode, type_size);
+   }
+}
+
+/**
+ * Return the offset soruce for a load/store intrinsic.
+ */
+nir_src *
+nir_get_io_offset_src(nir_intrinsic_instr *instr)
+{
+   switch (instr->intrinsic) {
+   case nir_intrinsic_load_input:
+   case nir_intrinsic_load_output:
+   case nir_intrinsic_load_uniform:
+      return &instr->src[0];
+   case nir_intrinsic_load_per_vertex_input:
+   case nir_intrinsic_load_per_vertex_output:
+   case nir_intrinsic_store_output:
+      return &instr->src[1];
+   case nir_intrinsic_store_per_vertex_output:
+      return &instr->src[2];
+   default:
+      return NULL;
+   }
+}
+
+/**
+ * Return the vertex index source for a load/store per_vertex intrinsic.
+ */
+nir_src *
+nir_get_io_vertex_index_src(nir_intrinsic_instr *instr)
+{
+   switch (instr->intrinsic) {
+   case nir_intrinsic_load_per_vertex_input:
+   case nir_intrinsic_load_per_vertex_output:
+      return &instr->src[0];
+   case nir_intrinsic_store_per_vertex_output:
+      return &instr->src[1];
+   default:
+      return NULL;
+   }
+}