/*
 * Copyright 2008 Nicolai Haehnle.
 * SPDX-License-Identifier: MIT
 */

#include "radeon_program.h"

#include <stdio.h>

#include "radeon_compiler.h"
#include "radeon_dataflow.h"

/**
 * Transform the given clause in the following way:
 *  1. Replace it with an empty clause
 *  2. For every instruction in the original clause, try the given
 *     transformations in order.
 *  3. If one of the transformations returns GL_TRUE, assume that it
 *     has emitted the appropriate instruction(s) into the new clause;
 *     otherwise, copy the instruction verbatim.
 *
 * \note The transformation is currently not recursive; in other words,
 * instructions emitted by transformations are not transformed.
 *
 * \note The transform is called 'local' because it can only look at
 * one instruction at a time.
 */
void
rc_local_transform(struct radeon_compiler *c, void *user)
{
   struct radeon_program_transformation *transformations =
      (struct radeon_program_transformation *)user;
   struct rc_instruction *inst = c->Program.Instructions.Next;

   while (inst != &c->Program.Instructions) {
      struct rc_instruction *current = inst;
      int i;

      inst = inst->Next;

      for (i = 0; transformations[i].function; ++i) {
         struct radeon_program_transformation *t = transformations + i;

         if (t->function(c, current, t->userData))
            break;
      }
   }
}

unsigned int
rc_find_free_temporary(struct radeon_compiler *c)
{
   /* Find the largest used temp index when called for the first time. */
   if (c->max_temp_index == -1) {
      for (struct rc_instruction *inst = c->Program.Instructions.Next;
           inst != &c->Program.Instructions; inst = inst->Next) {
         const struct rc_opcode_info *opcode = rc_get_opcode_info(inst->U.I.Opcode);
         if (opcode->HasDstReg && inst->U.I.DstReg.File == RC_FILE_TEMPORARY &&
             inst->U.I.WriteALUResult == RC_ALURESULT_NONE &&
             inst->U.I.DstReg.Index > c->max_temp_index)
            c->max_temp_index = inst->U.I.DstReg.Index;
      }
   }

   c->max_temp_index++;
   if (c->max_temp_index > RC_REGISTER_MAX_INDEX) {
      rc_error(c, "Ran out of temporary registers");
      return 0;
   }
   return c->max_temp_index;
}

struct rc_instruction *
rc_alloc_instruction(struct radeon_compiler *c)
{
   struct rc_instruction *inst = memory_pool_malloc(&c->Pool, sizeof(struct rc_instruction));

   memset(inst, 0, sizeof(struct rc_instruction));

   inst->U.I.Opcode = RC_OPCODE_ILLEGAL_OPCODE;
   inst->U.I.DstReg.WriteMask = RC_MASK_XYZW;
   inst->U.I.SrcReg[0].Swizzle = RC_SWIZZLE_XYZW;
   inst->U.I.SrcReg[1].Swizzle = RC_SWIZZLE_XYZW;
   inst->U.I.SrcReg[2].Swizzle = RC_SWIZZLE_XYZW;

   return inst;
}

void
rc_insert_instruction(struct rc_instruction *after, struct rc_instruction *inst)
{
   inst->Prev = after;
   inst->Next = after->Next;

   inst->Prev->Next = inst;
   inst->Next->Prev = inst;
}

struct rc_instruction *
rc_insert_new_instruction(struct radeon_compiler *c, struct rc_instruction *after)
{
   struct rc_instruction *inst = rc_alloc_instruction(c);

   rc_insert_instruction(after, inst);

   return inst;
}

void
rc_remove_instruction(struct rc_instruction *inst)
{
   inst->Prev->Next = inst->Next;
   inst->Next->Prev = inst->Prev;
}

/**
 * Return the number of instructions in the program.
 */
unsigned int
rc_recompute_ips(struct radeon_compiler *c)
{
   unsigned int ip = 0;
   struct rc_instruction *inst;

   for (inst = c->Program.Instructions.Next; inst != &c->Program.Instructions; inst = inst->Next) {
      inst->IP = ip++;
   }

   c->Program.Instructions.IP = 0xcafedead;

   return ip;
}