/*
 * Copyright (c) 2017 Lima Project
 *
 * 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, sub license,
 * 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 NON-INFRINGEMENT. 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.
 *
 */

#include "util/u_math.h"
#include "util/ralloc.h"
#include "util/bitscan.h"

#include "ppir.h"

const ppir_op_info ppir_op_infos[] = {
   [ppir_op_unsupported] = {
      .name = "unsupported",
   },
   [ppir_op_mov] = {
      .name = "mov",
      .slots = (int []) {
         PPIR_INSTR_SLOT_ALU_SCL_ADD, PPIR_INSTR_SLOT_ALU_SCL_MUL,
         PPIR_INSTR_SLOT_ALU_VEC_ADD, PPIR_INSTR_SLOT_ALU_VEC_MUL,
         PPIR_INSTR_SLOT_END
      },
   },
   [ppir_op_abs] = {
      .name = "abs",
   },
   [ppir_op_neg] = {
      .name = "neg",
   },
   [ppir_op_sat] = {
      .name = "sat",
   },
   [ppir_op_clamp_pos] = {
      .name = "clamp_pos",
   },
   [ppir_op_trunc] = {
      .name = "trunc",
   },
   [ppir_op_mul] = {
      .name = "mul",
      .slots = (int []) {
         PPIR_INSTR_SLOT_ALU_COMBINE,
         PPIR_INSTR_SLOT_ALU_SCL_MUL, PPIR_INSTR_SLOT_ALU_VEC_MUL,
         PPIR_INSTR_SLOT_END
      },
   },
   [ppir_op_add] = {
      .name = "add",
      .slots = (int []) {
         PPIR_INSTR_SLOT_ALU_SCL_ADD, PPIR_INSTR_SLOT_ALU_VEC_ADD,
         PPIR_INSTR_SLOT_END
      },
   },
   [ppir_op_sum3] = {
      .name = "sum3",
      .slots = (int []) {
         PPIR_INSTR_SLOT_ALU_VEC_ADD, PPIR_INSTR_SLOT_END
      },
   },
   [ppir_op_sum4] = {
      .name = "sum4",
      .slots = (int []) {
         PPIR_INSTR_SLOT_ALU_VEC_ADD, PPIR_INSTR_SLOT_END
      },
   },
   [ppir_op_rsqrt] = {
      .name = "rsqrt",
      .slots = (int []) {
         PPIR_INSTR_SLOT_ALU_COMBINE, PPIR_INSTR_SLOT_END
      },
   },
   [ppir_op_log2] = {
      .name = "log2",
      .slots = (int []) {
         PPIR_INSTR_SLOT_ALU_COMBINE, PPIR_INSTR_SLOT_END
      },
   },
   [ppir_op_exp2] = {
      .name = "exp2",
      .slots = (int []) {
         PPIR_INSTR_SLOT_ALU_COMBINE, PPIR_INSTR_SLOT_END
      },
   },
   [ppir_op_sqrt] = {
      .name = "sqrt",
      .slots = (int []) {
         PPIR_INSTR_SLOT_ALU_COMBINE, PPIR_INSTR_SLOT_END
      },
   },
   [ppir_op_sin] = {
      .name = "sin",
      .slots = (int []) {
         PPIR_INSTR_SLOT_ALU_COMBINE, PPIR_INSTR_SLOT_END
      },
   },
   [ppir_op_cos] = {
      .name = "cos",
      .slots = (int []) {
         PPIR_INSTR_SLOT_ALU_COMBINE, PPIR_INSTR_SLOT_END
      },
   },
   [ppir_op_max] = {
      .name = "max",
      .slots = (int []) {
         PPIR_INSTR_SLOT_ALU_SCL_ADD, PPIR_INSTR_SLOT_ALU_SCL_MUL,
         PPIR_INSTR_SLOT_ALU_VEC_ADD, PPIR_INSTR_SLOT_ALU_VEC_MUL,
         PPIR_INSTR_SLOT_END
      },
   },
   [ppir_op_min] = {
      .name = "min",
      .slots = (int []) {
         PPIR_INSTR_SLOT_ALU_SCL_ADD, PPIR_INSTR_SLOT_ALU_SCL_MUL,
         PPIR_INSTR_SLOT_ALU_VEC_ADD, PPIR_INSTR_SLOT_ALU_VEC_MUL,
         PPIR_INSTR_SLOT_END
      },
   },
   [ppir_op_floor] = {
      .name = "floor",
      .slots = (int []) {
         PPIR_INSTR_SLOT_ALU_SCL_ADD, PPIR_INSTR_SLOT_ALU_VEC_ADD,
         PPIR_INSTR_SLOT_END
      },
   },
   [ppir_op_ceil] = {
      .name = "ceil",
      .slots = (int []) {
         PPIR_INSTR_SLOT_ALU_SCL_ADD, PPIR_INSTR_SLOT_ALU_VEC_ADD,
         PPIR_INSTR_SLOT_END
      },
   },
   [ppir_op_fract] = {
      .name = "fract",
      .slots = (int []) {
         PPIR_INSTR_SLOT_ALU_SCL_ADD, PPIR_INSTR_SLOT_ALU_VEC_ADD,
         PPIR_INSTR_SLOT_END
      },
   },
   [ppir_op_ddx] = {
      .name = "ddx",
      .slots = (int []) {
         PPIR_INSTR_SLOT_ALU_SCL_ADD, PPIR_INSTR_SLOT_ALU_VEC_ADD,
         PPIR_INSTR_SLOT_END
      },
   },
   [ppir_op_ddy] = {
      .name = "ddy",
      .slots = (int []) {
         PPIR_INSTR_SLOT_ALU_SCL_ADD, PPIR_INSTR_SLOT_ALU_VEC_ADD,
         PPIR_INSTR_SLOT_END
      },
   },
   [ppir_op_and] = {
      .name = "and",
      .slots = (int []) {
         PPIR_INSTR_SLOT_ALU_SCL_MUL, PPIR_INSTR_SLOT_ALU_VEC_MUL,
         PPIR_INSTR_SLOT_END
      },
   },
   [ppir_op_or] = {
      .name = "or",
      .slots = (int []) {
         PPIR_INSTR_SLOT_ALU_SCL_MUL, PPIR_INSTR_SLOT_ALU_VEC_MUL,
         PPIR_INSTR_SLOT_END
      },
   },
   [ppir_op_xor] = {
      .name = "xor",
      .slots = (int []) {
         PPIR_INSTR_SLOT_ALU_SCL_MUL, PPIR_INSTR_SLOT_ALU_VEC_MUL,
         PPIR_INSTR_SLOT_END
      },
   },
   [ppir_op_not] = {
      .name = "not",
      .slots = (int []) {
         PPIR_INSTR_SLOT_ALU_SCL_MUL, PPIR_INSTR_SLOT_ALU_VEC_MUL,
         PPIR_INSTR_SLOT_END
      },
   },
   [ppir_op_lt] = {
      .name = "lt",
   },
   [ppir_op_le] = {
      .name = "le",
   },
   [ppir_op_gt] = {
      .name = "gt",
      .slots = (int []) {
         PPIR_INSTR_SLOT_ALU_SCL_MUL, PPIR_INSTR_SLOT_ALU_SCL_ADD,
         PPIR_INSTR_SLOT_ALU_VEC_MUL, PPIR_INSTR_SLOT_ALU_VEC_ADD,
         PPIR_INSTR_SLOT_END
      },
   },
   [ppir_op_ge] = {
      .name = "ge",
      .slots = (int []) {
         PPIR_INSTR_SLOT_ALU_SCL_MUL, PPIR_INSTR_SLOT_ALU_SCL_ADD,
         PPIR_INSTR_SLOT_ALU_VEC_MUL, PPIR_INSTR_SLOT_ALU_VEC_ADD,
         PPIR_INSTR_SLOT_END
      },
   },
   [ppir_op_eq] = {
      .name = "eq",
      .slots = (int []) {
         PPIR_INSTR_SLOT_ALU_SCL_MUL, PPIR_INSTR_SLOT_ALU_SCL_ADD,
         PPIR_INSTR_SLOT_ALU_VEC_MUL, PPIR_INSTR_SLOT_ALU_VEC_ADD,
         PPIR_INSTR_SLOT_END
      },
   },
   [ppir_op_ne] = {
      .name = "ne",
      .slots = (int []) {
         PPIR_INSTR_SLOT_ALU_SCL_MUL, PPIR_INSTR_SLOT_ALU_SCL_ADD,
         PPIR_INSTR_SLOT_ALU_VEC_MUL, PPIR_INSTR_SLOT_ALU_VEC_ADD,
         PPIR_INSTR_SLOT_END
      },
   },
   [ppir_op_select] = {
      .name = "select",
      .slots = (int []) {
         PPIR_INSTR_SLOT_ALU_SCL_ADD, PPIR_INSTR_SLOT_ALU_VEC_ADD,
         PPIR_INSTR_SLOT_END
      },
   },
   [ppir_op_rcp] = {
      .name = "rcp",
      .slots = (int []) {
         PPIR_INSTR_SLOT_ALU_COMBINE, PPIR_INSTR_SLOT_END
      },
   },
   [ppir_op_load_varying] = {
      .name = "ld_var",
      .type = ppir_node_type_load,
      .slots = (int []) {
         PPIR_INSTR_SLOT_VARYING, PPIR_INSTR_SLOT_END
      },
   },
   [ppir_op_load_coords] = {
      .name = "ld_coords",
      .type = ppir_node_type_load,
      .slots = (int []) {
         PPIR_INSTR_SLOT_VARYING, PPIR_INSTR_SLOT_END
      },
   },
   [ppir_op_load_coords_reg] = {
      .name = "ld_coords_reg",
      .type = ppir_node_type_load,
      .slots = (int []) {
         PPIR_INSTR_SLOT_VARYING, PPIR_INSTR_SLOT_END
      },
   },
   [ppir_op_load_fragcoord] = {
      .name = "ld_fragcoord",
      .type = ppir_node_type_load,
      .slots = (int []) {
         PPIR_INSTR_SLOT_VARYING, PPIR_INSTR_SLOT_END
      },
   },
   [ppir_op_load_pointcoord] = {
      .name = "ld_pointcoord",
      .type = ppir_node_type_load,
      .slots = (int []) {
         PPIR_INSTR_SLOT_VARYING, PPIR_INSTR_SLOT_END
      },
   },
   [ppir_op_load_frontface] = {
      .name = "ld_frontface",
      .type = ppir_node_type_load,
      .slots = (int []) {
         PPIR_INSTR_SLOT_VARYING, PPIR_INSTR_SLOT_END
      },
   },
   [ppir_op_load_uniform] = {
      .name = "ld_uni",
      .type = ppir_node_type_load,
      .slots = (int []) {
         PPIR_INSTR_SLOT_UNIFORM, PPIR_INSTR_SLOT_END
      },
   },
   [ppir_op_load_texture] = {
      .name = "ld_tex",
      .type = ppir_node_type_load_texture,
      .slots = (int []) {
         PPIR_INSTR_SLOT_TEXLD, PPIR_INSTR_SLOT_END
      },
   },
   [ppir_op_load_temp] = {
      .name = "ld_temp",
      .type = ppir_node_type_load,
      .slots = (int []) {
         PPIR_INSTR_SLOT_UNIFORM, PPIR_INSTR_SLOT_END
      },
   },
   [ppir_op_const] = {
      .name = "const",
      .type = ppir_node_type_const,
   },
   [ppir_op_store_temp] = {
      .name = "st_temp",
      .type = ppir_node_type_store,
      .slots = (int []) {
         PPIR_INSTR_SLOT_STORE_TEMP, PPIR_INSTR_SLOT_END
      },
   },
   [ppir_op_discard] = {
      .name = "discard",
      .type = ppir_node_type_discard,
      .slots = (int []) {
         PPIR_INSTR_SLOT_BRANCH, PPIR_INSTR_SLOT_END
      },
   },
   [ppir_op_branch] = {
      .name = "branch",
      .type = ppir_node_type_branch,
      .slots = (int []) {
         PPIR_INSTR_SLOT_BRANCH, PPIR_INSTR_SLOT_END
      },
   },
   [ppir_op_undef] = {
      .name = "undef",
      .type = ppir_node_type_alu,
      .slots = (int []) {
         PPIR_INSTR_SLOT_END
      },
   },
   [ppir_op_dummy] = {
      .name = "dummy",
      .type = ppir_node_type_alu,
      .slots = (int []) {
         PPIR_INSTR_SLOT_END
      },
   },
};

void *ppir_node_create(ppir_block *block, ppir_op op, int index, unsigned mask)
{
   ppir_compiler *comp = block->comp;
   static const int node_size[] = {
      [ppir_node_type_alu] = sizeof(ppir_alu_node),
      [ppir_node_type_const] = sizeof(ppir_const_node),
      [ppir_node_type_load] = sizeof(ppir_load_node),
      [ppir_node_type_store] = sizeof(ppir_store_node),
      [ppir_node_type_load_texture] = sizeof(ppir_load_texture_node),
      [ppir_node_type_discard] = sizeof(ppir_discard_node),
      [ppir_node_type_branch] = sizeof(ppir_branch_node),
   };

   ppir_node_type type = ppir_op_infos[op].type;
   int size = node_size[type];
   ppir_node *node = rzalloc_size(block, size);
   if (!node)
      return NULL;

   list_inithead(&node->succ_list);
   list_inithead(&node->pred_list);

   if (index >= 0) {
      if (mask) {
         /* reg has 4 slots for each component write node */
         while (mask)
            comp->var_nodes[(index << 2) + u_bit_scan(&mask)] = node;
         snprintf(node->name, sizeof(node->name), "reg%d", index);
      } else {
         comp->var_nodes[index << 2] = node;
         snprintf(node->name, sizeof(node->name), "ssa%d", index);
      }
   }
   else
      snprintf(node->name, sizeof(node->name), "new");

   node->op = op;
   node->type = type;
   node->index = comp->cur_index++;
   node->block = block;

   return node;
}

void ppir_node_add_dep(ppir_node *succ, ppir_node *pred,
                       ppir_dep_type type)
{
   /* don't add dep for two nodes from different block */
   if (succ->block != pred->block) {
      pred->succ_different_block = true;
      return;
   }

   /* don't add duplicated dep */
   ppir_node_foreach_pred(succ, dep) {
      if (dep->pred == pred)
         return;
   }

   ppir_dep *dep = ralloc(succ, ppir_dep);
   dep->pred = pred;
   dep->succ = succ;
   dep->type = type;
   list_addtail(&dep->pred_link, &succ->pred_list);
   list_addtail(&dep->succ_link, &pred->succ_list);
}

void ppir_node_remove_dep(ppir_dep *dep)
{
   list_del(&dep->succ_link);
   list_del(&dep->pred_link);
   ralloc_free(dep);
}

static void _ppir_node_replace_child(ppir_src *src, ppir_node *old_child, ppir_node *new_child)
{
   ppir_dest *od = ppir_node_get_dest(old_child);
   if (ppir_node_target_equal(src, od)) {
      ppir_node_target_assign(src, new_child);
   }
}

void ppir_node_replace_child(ppir_node *parent, ppir_node *old_child, ppir_node *new_child)
{
   switch (parent->type) {
   case ppir_node_type_alu:
   {
      ppir_alu_node *alu = ppir_node_to_alu(parent);
      for (int i = 0; i < alu->num_src; i++)
         _ppir_node_replace_child(alu->src + i, old_child, new_child);
      break;
   }
   case ppir_node_type_branch:
   {
      ppir_branch_node *branch = ppir_node_to_branch(parent);
      for (int i = 0; i < 2; i++)
         _ppir_node_replace_child(branch->src + i, old_child, new_child);
      break;
   }
   case ppir_node_type_load:
   {
      ppir_load_node *load = ppir_node_to_load(parent);
      _ppir_node_replace_child(&load->src, old_child, new_child);
      break;
   }
   case ppir_node_type_load_texture:
   {
      ppir_load_texture_node *load_texture = ppir_node_to_load_texture(parent);
      for (int i = 0; i < load_texture->num_src; i++)
         _ppir_node_replace_child(ppir_node_get_src(parent, i), old_child, new_child);
      break;
   }
   case ppir_node_type_store:
   {
      ppir_store_node *store = ppir_node_to_store(parent);
      _ppir_node_replace_child(&store->src, old_child, new_child);
      break;
   }
   default:
      ppir_debug("unknown node type in %s\n", __func__);
      break;
   }
}

void ppir_node_replace_pred(ppir_dep *dep, ppir_node *new_pred)
{
   list_del(&dep->succ_link);
   dep->pred = new_pred;
   list_addtail(&dep->succ_link, &new_pred->succ_list);
}

ppir_dep *ppir_dep_for_pred(ppir_node *node, ppir_node *pred)
{
   if (!pred)
      return NULL;

   if (node->block != pred->block)
      return NULL;

   ppir_node_foreach_pred(node, dep) {
      if (dep->pred == pred)
         return dep;
   }
   return NULL;
}

void ppir_node_replace_all_succ(ppir_node *dst, ppir_node *src)
{
   ppir_node_foreach_succ_safe(src, dep) {
      ppir_node_replace_pred(dep, dst);
      ppir_node_replace_child(dep->succ, src, dst);
   }
}

void ppir_node_delete(ppir_node *node)
{
   ppir_node_foreach_succ_safe(node, dep)
      ppir_node_remove_dep(dep);

   ppir_node_foreach_pred_safe(node, dep)
      ppir_node_remove_dep(dep);

   list_del(&node->list);
   ralloc_free(node);
}

static void ppir_node_print_const(ppir_node *node)
{
   ppir_const_node *cst = ppir_node_to_const(node);

   printf("(");

   for (int i = 0; i < cst->constant.num; i++) {
      if (i != 0)
         printf(", ");
      printf("%f", cst->constant.value[i].f);
   }

   printf(")");
}

static void ppir_node_print_dest(ppir_node *node)
{
   ppir_dest *dest = ppir_node_get_dest(node);

   if (!dest)
      return;

   switch (dest->type) {
   case ppir_target_ssa:
      printf(" $%.4d", node->index);
      break;
   case ppir_target_pipeline:
      printf("($%.4d) %s", node->index, ppir_pipeline_reg_to_str(dest->pipeline));
      break;
   case ppir_target_register:
      printf("($%.4d) reg_%d", node->index, dest->reg->index);
      break;
   }

   if (dest->type != ppir_target_pipeline && dest->write_mask != 0xf) {
      const char xyzw[] = "xyzw";
      printf(".");
      for (int i = 0; i < 4; i++) {
         if (dest->write_mask & (1 << i)) {
            printf("%c", xyzw[i]);
         }
      }
   }

   printf(" = ");

   switch (dest->modifier) {
   case ppir_outmod_none:
      break;
   case ppir_outmod_clamp_fraction:
      printf("clamp_frac ");
      break;
   case ppir_outmod_clamp_positive:
      printf("clamp_pos ");
      break;
   case ppir_outmod_round:
      printf("round ");
      break;
   default:
      break;
   }

}

static void ppir_node_print_src(ppir_src *src)
{
   if (src->negate)
      printf("-");
   if (src->absolute)
      printf("abs(");
   switch (src->type) {
   case ppir_target_ssa: {
      if (src->node)
         printf("$%.4d", src->node->index);
      else
         printf("ssa_%d", src->ssa ? src->ssa->index : -1);
      break;
   }
   case ppir_target_pipeline:
      if (src->node)
         printf("%s ($%.4d)", ppir_pipeline_reg_to_str(src->pipeline), src->node->index);
      else
         printf("%s", ppir_pipeline_reg_to_str(src->pipeline));
      break;
   case ppir_target_register:
      printf("reg_%d", src->reg->index);
      break;
   }

   uint8_t identity[] = {0, 1, 2, 3};
   if (memcmp(src->swizzle, identity, sizeof(identity)) != 0)
   {
      printf(".");
      for (int i = 0; i < 4; i++) {
         printf("%c", "xyzw"[src->swizzle[i]]);
      }
   }
   if (src->absolute)
      printf(")");
}

static void ppir_node_print_branch_src(ppir_branch_node *branch)
{
   if (!branch->num_src)
      return;

   assert(branch->num_src <= 2);

   switch (branch->num_src) {
   /* Unconditional branch */
   case 0:
      return;
   case 1:
      printf("if (");
      if (branch->negate)
         printf("!");
      ppir_node_print_src(ppir_node_get_src(&branch->node, 0));
      printf(")");
      return;
   case 2:
      printf("if (");
      ppir_node_print_src(ppir_node_get_src(&branch->node, 0));
      if (branch->cond_eq && !branch->cond_gt && !branch->cond_lt) {
         printf(" == ");
      } else if (!branch->cond_eq && branch->cond_gt && branch->cond_lt) {
         printf(" != ");
      } else {
         printf(" ");
         if (branch->cond_gt)
            printf(">");
         if (branch->cond_lt)
            printf("<");
         if (branch->cond_eq)
            printf("=");
         printf(" ");
      }
      ppir_node_print_src(ppir_node_get_src(&branch->node, 1));
      printf(")");
      return;
   default:
      return;
   }
}

static void ppir_node_print_node(ppir_node *node, int space)
{
   for (int i = 0; i < space; i++)
      printf(" ");

   /* Print "+" if node is not a leaf and it is already printed */
   if (node->printed && !ppir_node_is_leaf(node)) {
      printf("+");
   }

   ppir_node_print_dest(node);

   printf("%s ", ppir_op_infos[node->op].name);

   if (node->op == ppir_op_load_uniform || node->op == ppir_op_load_varying) {
      ppir_load_node *load = ppir_node_to_load(node);
      printf("%d", load->index);
      if (ppir_node_get_src_num(node) != 0)
         printf(" + ");
   }

   if (node->op != ppir_op_branch) {
      for (int i = 0; i < ppir_node_get_src_num(node); i++) {
         if (i != 0)
            printf(", ");
         ppir_node_print_src(ppir_node_get_src(node, i));
      }
   } else {
      ppir_branch_node *branch = ppir_node_to_branch(node);
      ppir_node_print_branch_src(branch);
      printf(" block_%d", branch->target->index);
   }

   if (node->op == ppir_op_const)
      ppir_node_print_const(node);

   printf(" // NIR: %s\n", node->name);

   if (!node->printed) {
      ppir_node_foreach_pred(node, dep) {
         ppir_node *pred = dep->pred;
         ppir_node_print_node(pred, space + 2);
      }

      node->printed = true;
   }
}

void ppir_node_print_prog(ppir_compiler *comp)
{
   if (!(lima_debug & LIMA_DEBUG_PP))
      return;

   list_for_each_entry(ppir_block, block, &comp->block_list, list) {
      list_for_each_entry(ppir_node, node, &block->node_list, list) {
         node->printed = false;
      }
   }

   printf("========prog========\n");
   list_for_each_entry(ppir_block, block, &comp->block_list, list) {
      printf("*** block %3d", block->index);
      if (block->successors[0] || block->successors[1]) {
         printf(", successors:");
         for (int i = 0; i < 2; i++) {
            if (block->successors[i])
               printf(" %d", block->successors[i]->index);
         }
      }
      if (block->stop)
         printf(", stop");
      printf("\n");
      list_for_each_entry(ppir_node, node, &block->node_list, list) {
         if (ppir_node_is_root(node))
            ppir_node_print_node(node, 0);
      }
   }
   printf("====================\n");
}

static ppir_node *ppir_node_insert_mov_local(ppir_node *node)
{
   ppir_node *move = ppir_node_create(node->block, ppir_op_mov, -1, 0);
   if (unlikely(!move))
      return NULL;

   ppir_dest *dest = ppir_node_get_dest(node);
   ppir_alu_node *alu = ppir_node_to_alu(move);
   alu->dest = *dest;
   alu->num_src = 1;
   ppir_node_target_assign(alu->src, node);

   for (int s = 0; s < 4; s++)
      alu->src->swizzle[s] = s;

   ppir_node_replace_all_succ(move, node);
   ppir_node_add_dep(move, node, ppir_dep_src);
   list_addtail(&move->list, &node->list);

   if (node->is_out) {
      node->is_out = false;
      move->is_out = true;
   }

   return move;
}

ppir_node *ppir_node_insert_mov(ppir_node *old)
{
   ppir_node *move = ppir_node_insert_mov_local(old);
   ppir_compiler *comp = old->block->comp;

   list_for_each_entry(ppir_block, block, &comp->block_list, list) {
      if (old->block == block)
         continue;
      list_for_each_entry_safe(ppir_node, node, &block->node_list, list) {
         for (int i = 0; i < ppir_node_get_src_num(node); i++){
            ppir_src *src = ppir_node_get_src(node, i);
            if (!src)
               continue;
            if (src->node == old)
               ppir_node_target_assign(src, move);
         }
      }
   }

   return move;
}

bool ppir_node_has_single_src_succ(ppir_node *node)
{
   if (ppir_node_has_single_succ(node) &&
       list_first_entry(&node->succ_list,
                        ppir_dep, succ_link)->type == ppir_dep_src)
      return true;

   int cnt = 0;
   ppir_node_foreach_succ(node, dep) {
      if (dep->type != ppir_dep_src)
         continue;
      cnt++;
   }

   return cnt == 1;
}
