nir: move to compiler/

Signed-off-by: Emil Velikov <emil.velikov@collabora.com>
Acked-by: Matt Turner <mattst88@gmail.com>
Acked-by: Jose Fonseca <jfonseca@vmware.com>

1 files changed, 201 insertions, 0 deletions

diff --git a/src/compiler/nir/nir_opt_constant_folding.c b/src/compiler/nir/nir_opt_constant_folding.c
new file mode 100644
index 0000000..28a73f8
--- /dev/null
+++ b/src/compiler/nir/nir_opt_constant_folding.c
@@ -0,0 +1,201 @@
+/*
+ * 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:
+ *    Jason Ekstrand (jason@jlekstrand.net)
+ *
+ */
+
+#include "nir_constant_expressions.h"
+#include <math.h>
+
+/*
+ * Implements SSA-based constant folding.
+ */
+
+struct constant_fold_state {
+   void *mem_ctx;
+   nir_function_impl *impl;
+   bool progress;
+};
+
+static bool
+constant_fold_alu_instr(nir_alu_instr *instr, void *mem_ctx)
+{
+   nir_const_value src[4];
+
+   if (!instr->dest.dest.is_ssa)
+      return false;
+
+   for (unsigned i = 0; i < nir_op_infos[instr->op].num_inputs; i++) {
+      if (!instr->src[i].src.is_ssa)
+         return false;
+
+      nir_instr *src_instr = instr->src[i].src.ssa->parent_instr;
+
+      if (src_instr->type != nir_instr_type_load_const)
+         return false;
+      nir_load_const_instr* load_const = nir_instr_as_load_const(src_instr);
+
+      for (unsigned j = 0; j < nir_ssa_alu_instr_src_components(instr, i);
+           j++) {
+         src[i].u[j] = load_const->value.u[instr->src[i].swizzle[j]];
+      }
+
+      /* We shouldn't have any source modifiers in the optimization loop. */
+      assert(!instr->src[i].abs && !instr->src[i].negate);
+   }
+
+   /* We shouldn't have any saturate modifiers in the optimization loop. */
+   assert(!instr->dest.saturate);
+
+   nir_const_value dest =
+      nir_eval_const_opcode(instr->op, instr->dest.dest.ssa.num_components,
+                            src);
+
+   nir_load_const_instr *new_instr =
+      nir_load_const_instr_create(mem_ctx,
+                                  instr->dest.dest.ssa.num_components);
+
+   new_instr->value = dest;
+
+   nir_instr_insert_before(&instr->instr, &new_instr->instr);
+
+   nir_ssa_def_rewrite_uses(&instr->dest.dest.ssa,
+                            nir_src_for_ssa(&new_instr->def));
+
+   nir_instr_remove(&instr->instr);
+   ralloc_free(instr);
+
+   return true;
+}
+
+static bool
+constant_fold_deref(nir_instr *instr, nir_deref_var *deref)
+{
+   bool progress = false;
+
+   for (nir_deref *tail = deref->deref.child; tail; tail = tail->child) {
+      if (tail->deref_type != nir_deref_type_array)
+         continue;
+
+      nir_deref_array *arr = nir_deref_as_array(tail);
+
+      if (arr->deref_array_type == nir_deref_array_type_indirect &&
+          arr->indirect.is_ssa &&
+          arr->indirect.ssa->parent_instr->type == nir_instr_type_load_const) {
+         nir_load_const_instr *indirect =
+            nir_instr_as_load_const(arr->indirect.ssa->parent_instr);
+
+         arr->base_offset += indirect->value.u[0];
+
+         /* Clear out the source */
+         nir_instr_rewrite_src(instr, &arr->indirect, nir_src_for_ssa(NULL));
+
+         arr->deref_array_type = nir_deref_array_type_direct;
+
+         progress = true;
+      }
+   }
+
+   return progress;
+}
+
+static bool
+constant_fold_intrinsic_instr(nir_intrinsic_instr *instr)
+{
+   bool progress = false;
+
+   unsigned num_vars = nir_intrinsic_infos[instr->intrinsic].num_variables;
+   for (unsigned i = 0; i < num_vars; i++) {
+      progress |= constant_fold_deref(&instr->instr, instr->variables[i]);
+   }
+
+   return progress;
+}
+
+static bool
+constant_fold_tex_instr(nir_tex_instr *instr)
+{
+   if (instr->sampler)
+      return constant_fold_deref(&instr->instr, instr->sampler);
+   else
+      return false;
+}
+
+static bool
+constant_fold_block(nir_block *block, void *void_state)
+{
+   struct constant_fold_state *state = void_state;
+
+   nir_foreach_instr_safe(block, instr) {
+      switch (instr->type) {
+      case nir_instr_type_alu:
+         state->progress |= constant_fold_alu_instr(nir_instr_as_alu(instr),
+                                                    state->mem_ctx);
+         break;
+      case nir_instr_type_intrinsic:
+         state->progress |=
+            constant_fold_intrinsic_instr(nir_instr_as_intrinsic(instr));
+         break;
+      case nir_instr_type_tex:
+         state->progress |= constant_fold_tex_instr(nir_instr_as_tex(instr));
+         break;
+      default:
+         /* Don't know how to constant fold */
+         break;
+      }
+   }
+
+   return true;
+}
+
+static bool
+nir_opt_constant_folding_impl(nir_function_impl *impl)
+{
+   struct constant_fold_state state;
+
+   state.mem_ctx = ralloc_parent(impl);
+   state.impl = impl;
+   state.progress = false;
+
+   nir_foreach_block(impl, constant_fold_block, &state);
+
+   if (state.progress)
+      nir_metadata_preserve(impl, nir_metadata_block_index |
+                                  nir_metadata_dominance);
+
+   return state.progress;
+}
+
+bool
+nir_opt_constant_folding(nir_shader *shader)
+{
+   bool progress = false;
+
+   nir_foreach_function(shader, function) {
+      if (function->impl)
+         progress |= nir_opt_constant_folding_impl(function->impl);
+   }
+
+   return progress;
+}