#include "config.h"

#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <stdarg.h>

#include <orc/orcprogram.h>
#include <orc/orcdebug.h>

/**
 * SECTION:orccompiler
 * @title: OrcCompiler
 * @short_description: Compile Orc programs
 *
 * OrcCompiler is the object used to convert Orc programs contained
 * in an OrcProgram object into assembly code and object code.
 *
 * The OrcCompileResult enum is used to indicate whether or not
 * a compilation attempt was successful or not.  The macros
 * ORC_COMPILE_RESULT_IS_SUCCESSFUL() and ORC_COMPILE_RESULT_IS_FATAL()
 * should be used instead of checking values directly.
 *
 * When a program is compiled, the compiler calls the functions
 * contained in various OrcRule structures.  These functions generate
 * assembly and object instructions by calling ORC_ASM_CODE()
 * or functions that use ORC_ASM_CODE() internally.
 */

void orc_compiler_assign_rules (OrcCompiler *compiler);
void orc_compiler_global_reg_alloc (OrcCompiler *compiler);
void orc_compiler_rewrite_vars (OrcCompiler *compiler);
void orc_compiler_rewrite_vars2 (OrcCompiler *compiler);
int orc_compiler_dup_temporary (OrcCompiler *compiler, int var, int j);
void orc_compiler_check_sizes (OrcCompiler *compiler);

static char **_orc_compiler_flag_list;
int _orc_compiler_flag_backup;
int _orc_compiler_flag_debug;

void
_orc_compiler_init (void)
{
  const char *envvar;

  envvar = getenv ("ORC_CODE");
  if (envvar != NULL) {
    _orc_compiler_flag_list = strsplit (envvar, ',');
  }

  _orc_compiler_flag_backup = orc_compiler_flag_check ("backup");
  _orc_compiler_flag_debug = orc_compiler_flag_check ("debug");
}

int
orc_compiler_flag_check (const char *flag)
{
  int i;

  if (_orc_compiler_flag_list == NULL) return FALSE;

  for (i=0;_orc_compiler_flag_list[i];i++){
    if (strcmp (_orc_compiler_flag_list[i], flag) == 0) return TRUE;
  }
  return FALSE;
}

int
orc_compiler_allocate_register (OrcCompiler *compiler, int data_reg)
{
  int i;
  int roff;
  int reg;
  int offset;

  if (data_reg) {
    offset = compiler->target->data_register_offset;
  } else {
    offset = ORC_GP_REG_BASE;
  }

  roff = 0;
#if 0
  /* for testing */
  roff = rand()&0xf;
#endif

  for(i=0;i<32;i++){
    reg = offset + ((roff + i)&0x1f);
    if (compiler->valid_regs[reg] &&
        !compiler->save_regs[reg] &&
        compiler->alloc_regs[reg] == 0) {
      compiler->alloc_regs[reg]++;
      compiler->used_regs[reg] = 1;
      return reg;
    }
  }
  for(i=0;i<32;i++){
    reg = offset + ((roff + i)&0x1f);
    if (compiler->valid_regs[reg] &&
        compiler->alloc_regs[reg] == 0) {
      compiler->alloc_regs[reg]++;
      compiler->used_regs[reg] = 1;
      return reg;
    }
  }

  /* FIXME on !x86, this is an error */
  ORC_COMPILER_ERROR (compiler, "register overflow for %s reg",
      data_reg ? "vector" : "gp");
  compiler->result = ORC_COMPILE_RESULT_UNKNOWN_COMPILE;

  return 0;
}

/**
 * orc_program_compile:
 * @program: the OrcProgram to compile
 *
 * Compiles an Orc program for the current CPU.  If successful,
 * executable code for the program was generated and can be
 * executed.
 *
 * The return value indicates various levels of success or failure.
 * Success can be determined by checking for a true value of the
 * macro ORC_COMPILE_RESULT_IS_SUCCESSFUL() on the return value.  This
 * indicates that executable code was generated.  If the macro
 * ORC_COMPILE_RESULT_IS_FATAL() on the return value evaluates to
 * true, then there was a syntactical error in the program.  If the
 * result is neither successful nor fatal, the program can still be
 * emulated.
 *
 * Returns: an OrcCompileResult
 */
OrcCompileResult
orc_program_compile (OrcProgram *program)
{
  return orc_program_compile_for_target (program, orc_target_get_default ());
}

/**
 * orc_program_compile_for_target:
 * @program: the OrcProgram to compile
 *
 * Compiles an Orc program for the given target, using the
 * default target flags for that target.
 *
 * Returns: an OrcCompileResult
 */
OrcCompileResult
orc_program_compile_for_target (OrcProgram *program, OrcTarget *target)
{
  unsigned int flags;

  if (target) {
    flags = target->get_default_flags ();
  } else {
    flags = 0;
  }

  return orc_program_compile_full (program, target, flags);
}

/**
 * orc_program_compile_full:
 * @program: the OrcProgram to compile
 *
 * Compiles an Orc program for the given target, using the
 * given target flags.
 *
 * Returns: an OrcCompileResult
 */
OrcCompileResult
orc_program_compile_full (OrcProgram *program, OrcTarget *target,
    unsigned int flags)
{
  OrcCompiler *compiler;
  int i;
  OrcCompileResult result;

  ORC_INFO("initializing compiler for program \"%s\"", program->name);
  compiler = malloc (sizeof(OrcCompiler));
  memset (compiler, 0, sizeof(OrcCompiler));

  if (program->backup_func) {
    program->code = program->backup_func;
  } else {
    program->code = (void *)orc_executor_emulate;
  }

  compiler->program = program;
  compiler->target = target;
  compiler->target_flags = flags;

  if (program->backup_func && _orc_compiler_flag_backup) {
    ORC_COMPILER_ERROR(compiler, "Compilation disabled");
    compiler->result = ORC_COMPILE_RESULT_UNKNOWN_COMPILE;
    goto error;
  }

  if (target == NULL) {
    ORC_COMPILER_ERROR(compiler, "No target given");
    compiler->result = ORC_COMPILE_RESULT_UNKNOWN_COMPILE;
    goto error;
  }

  {
    ORC_LOG("variables");
    for(i=0;i<ORC_N_VARIABLES;i++){
      if (program->vars[i].size > 0) {
        ORC_LOG("%d: %s %d %d", i,
            program->vars[i].name,
            program->vars[i].size,
            program->vars[i].vartype);
      }
    }
    ORC_LOG("instructions");
    for(i=0;i<program->n_insns;i++){
      ORC_LOG("%d: %s %d %d %d %d", i,
          program->insns[i].opcode->name,
          program->insns[i].dest_args[0],
          program->insns[i].dest_args[1],
          program->insns[i].src_args[0],
          program->insns[i].src_args[1]);
    }
  }

  memcpy (compiler->insns, program->insns,
      program->n_insns * sizeof(OrcInstruction));
  compiler->n_insns = program->n_insns;

  memcpy (compiler->vars, program->vars,
      ORC_N_VARIABLES * sizeof(OrcVariable));
  compiler->n_temp_vars = program->n_temp_vars;
  compiler->n_dup_vars = 0;

  for(i=0;i<32;i++) {
    compiler->valid_regs[i] = 1;
  }

  compiler->target->compiler_init (compiler);

  orc_compiler_check_sizes (compiler);
  if (compiler->error) goto error;

  orc_compiler_assign_rules (compiler);
  if (compiler->error) goto error;

  orc_compiler_rewrite_vars (compiler);
  if (compiler->error) goto error;

  orc_compiler_global_reg_alloc (compiler);

  orc_compiler_rewrite_vars2 (compiler);
  if (compiler->error) goto error;

  ORC_INFO("allocating code memory");
  orc_compiler_allocate_codemem (compiler);

  ORC_INFO("compiling for target");
  compiler->target->compile (compiler);
  if (compiler->error) goto error;

  program->asm_code = compiler->asm_code;
  program->code_size = compiler->codeptr - program->code;

  result = compiler->result;
  for (i=0;i<compiler->n_dup_vars;i++){
    free(compiler->vars[ORC_VAR_T1 + compiler->n_temp_vars + i].name);
  }
  free (compiler);
  ORC_INFO("finished compiling (success)");

  return result;
error:

  ORC_WARNING("program %s failed to compile, reason %d",
      program->name, compiler->result);
  result = compiler->result;
  if (result == 0) {
    result = ORC_COMPILE_RESULT_UNKNOWN_COMPILE;
  }
  if (compiler->asm_code) free (compiler->asm_code);
  for (i=0;i<compiler->n_dup_vars;i++){
    free(compiler->vars[ORC_VAR_T1 + compiler->n_temp_vars + i].name);
  }
  free (compiler);
  ORC_INFO("finished compiling (fail)");
  return result;
}

void
orc_compiler_check_sizes (OrcCompiler *compiler)
{
  int i;
  int j;

  for(i=0;i<compiler->n_insns;i++) {
    OrcInstruction *insn = compiler->insns + i;
    OrcStaticOpcode *opcode = insn->opcode;

    for(j=0;j<ORC_STATIC_OPCODE_N_DEST;j++){
      if (opcode->dest_size[j] == 0) continue;
      if (opcode->dest_size[j] != compiler->vars[insn->dest_args[j]].size) {
        ORC_COMPILER_ERROR(compiler, "size mismatch, opcode %s dest[%d] is %d should be %d",
            opcode->name, j, compiler->vars[insn->dest_args[j]].size,
            opcode->dest_size[j]);
        compiler->result = ORC_COMPILE_RESULT_UNKNOWN_PARSE;
        return;
      }
    }
    for(j=0;j<ORC_STATIC_OPCODE_N_SRC;j++){
      if (opcode->src_size[j] == 0) continue;
      if (opcode->src_size[j] != compiler->vars[insn->src_args[j]].size &&
          compiler->vars[insn->src_args[j]].vartype != ORC_VAR_TYPE_PARAM &&
          compiler->vars[insn->src_args[j]].vartype != ORC_VAR_TYPE_CONST) {
        ORC_COMPILER_ERROR(compiler, "size mismatch, opcode %s src[%d] is %d should be %d",
            opcode->name, j, compiler->vars[insn->src_args[j]].size,
            opcode->src_size[j]);
        compiler->result = ORC_COMPILE_RESULT_UNKNOWN_PARSE;
        return;
      }
      if (opcode->flags & ORC_STATIC_OPCODE_SCALAR && j >= 1 &&
          compiler->vars[insn->src_args[j]].vartype != ORC_VAR_TYPE_PARAM &&
          compiler->vars[insn->src_args[j]].vartype != ORC_VAR_TYPE_CONST) {
        ORC_COMPILER_ERROR(compiler, "opcode %s requires const or param source",
            opcode->name);
        compiler->result = ORC_COMPILE_RESULT_UNKNOWN_PARSE;
        return;

      }
    }
  }
}

void
orc_compiler_assign_rules (OrcCompiler *compiler)
{
  int i;

  for(i=0;i<compiler->n_insns;i++) {
    OrcInstruction *insn = compiler->insns + i;

    insn->rule = orc_target_get_rule (compiler->target, insn->opcode,
        compiler->target_flags);

    if (insn->rule == NULL || insn->rule->emit == NULL) {
      ORC_COMPILER_ERROR(compiler, "No rule for: %s on target %s",
          insn->opcode->name, compiler->target->name);
      compiler->result = ORC_COMPILE_RESULT_UNKNOWN_COMPILE;
      return;
    }
  }
}

void
orc_compiler_rewrite_vars (OrcCompiler *compiler)
{
  int j;
  int k;
  OrcInstruction *insn;
  OrcStaticOpcode *opcode;
  int var;
  int actual_var;

  for(j=0;j<compiler->n_insns;j++){
    insn = compiler->insns + j;
    opcode = insn->opcode;

    /* set up args */
    for(k=0;k<ORC_STATIC_OPCODE_N_SRC;k++){
      if (opcode->src_size[k] == 0) continue;

      var = insn->src_args[k];
      if (compiler->vars[var].vartype == ORC_VAR_TYPE_DEST) {
        compiler->vars[var].load_dest = TRUE;
      }

      actual_var = var;
      if (compiler->vars[var].replaced) {
        actual_var = compiler->vars[var].replacement;
        insn->src_args[k] = actual_var;
      }

      if (!compiler->vars[var].used) {
        if (compiler->vars[var].vartype == ORC_VAR_TYPE_TEMP) {
          ORC_COMPILER_ERROR(compiler, "using uninitialized temp var");
          compiler->result = ORC_COMPILE_RESULT_UNKNOWN_PARSE;
        }
        compiler->vars[var].used = TRUE;
        compiler->vars[var].first_use = j;
      }
      compiler->vars[actual_var].last_use = j;
    }

    for(k=0;k<ORC_STATIC_OPCODE_N_DEST;k++){
      if (opcode->dest_size[k] == 0) continue;

      var = insn->dest_args[k];

      if (compiler->vars[var].vartype == ORC_VAR_TYPE_SRC) {
        ORC_COMPILER_ERROR(compiler,"using src var as dest");
        compiler->result = ORC_COMPILE_RESULT_UNKNOWN_PARSE;
      }
      if (compiler->vars[var].vartype == ORC_VAR_TYPE_CONST) {
        ORC_COMPILER_ERROR(compiler,"using const var as dest");
        compiler->result = ORC_COMPILE_RESULT_UNKNOWN_PARSE;
      }
      if (compiler->vars[var].vartype == ORC_VAR_TYPE_PARAM) {
        ORC_COMPILER_ERROR(compiler,"using param var as dest");
        compiler->result = ORC_COMPILE_RESULT_UNKNOWN_PARSE;
      }
      if (opcode->flags & ORC_STATIC_OPCODE_ACCUMULATOR) {
        if (compiler->vars[var].vartype != ORC_VAR_TYPE_ACCUMULATOR) {
          ORC_COMPILER_ERROR(compiler,"accumulating opcode to non-accumulator dest");
          compiler->result = ORC_COMPILE_RESULT_UNKNOWN_PARSE;
        }
      } else {
        if (compiler->vars[var].vartype == ORC_VAR_TYPE_ACCUMULATOR) {
          ORC_COMPILER_ERROR(compiler,"non-accumulating opcode to accumulator dest");
          compiler->result = ORC_COMPILE_RESULT_UNKNOWN_PARSE;
        }
      }

      actual_var = var;
      if (compiler->vars[var].replaced) {
        actual_var = compiler->vars[var].replacement;
        insn->dest_args[k] = actual_var;
      }

      if (!compiler->vars[var].used) {
        compiler->vars[actual_var].used = TRUE;
        compiler->vars[actual_var].first_use = j;
      } else {
#if 0
        if (compiler->vars[var].vartype == ORC_VAR_TYPE_DEST) {
          ORC_COMPILER_ERROR(compiler,"writing dest more than once");
          compiler->result = ORC_COMPILE_RESULT_UNKNOWN_PARSE;
        }
#endif
        if (compiler->vars[var].vartype == ORC_VAR_TYPE_TEMP) {
          actual_var = orc_compiler_dup_temporary (compiler, var, j);
          compiler->vars[var].replaced = TRUE;
          compiler->vars[var].replacement = actual_var;
          insn->dest_args[k] = actual_var;
          compiler->vars[actual_var].used = TRUE;
          compiler->vars[actual_var].first_use = j;
        }
      }
      compiler->vars[actual_var].last_use = j;
    }
  }
}

void
orc_compiler_global_reg_alloc (OrcCompiler *compiler)
{
  int i;
  OrcVariable *var;


  for(i=0;i<ORC_N_VARIABLES;i++){
    var = compiler->vars + i;
    if (var->name == NULL) continue;
    switch (var->vartype) {
      case ORC_VAR_TYPE_CONST:
        var->first_use = -1;
        var->last_use = -1;
        var->alloc = orc_compiler_allocate_register (compiler, TRUE);
        break;
      case ORC_VAR_TYPE_PARAM:
        var->first_use = -1;
        var->last_use = -1;
        var->alloc = orc_compiler_allocate_register (compiler, TRUE);
        break;
      case ORC_VAR_TYPE_SRC:
        var->ptr_register = orc_compiler_allocate_register (compiler, FALSE);
        if (compiler->need_mask_regs) {
          var->mask_alloc = orc_compiler_allocate_register (compiler, TRUE);
          var->ptr_offset = orc_compiler_allocate_register (compiler, FALSE);
          var->aligned_data = orc_compiler_allocate_register (compiler, TRUE);
        }
        break;
      case ORC_VAR_TYPE_DEST:
        var->ptr_register = orc_compiler_allocate_register (compiler, FALSE);
        break;
      case ORC_VAR_TYPE_ACCUMULATOR:
        var->first_use = -1;
        var->last_use = -1;
        var->alloc = orc_compiler_allocate_register (compiler, TRUE);
        break;
      case ORC_VAR_TYPE_TEMP:
        break;
      default:
        ORC_COMPILER_ERROR(compiler, "bad vartype");
        compiler->result = ORC_COMPILE_RESULT_UNKNOWN_PARSE;
        break;
    }

    if (compiler->error) break;
  }

  if (compiler->alloc_loop_counter && !compiler->error) {
    compiler->loop_counter = orc_compiler_allocate_register (compiler, FALSE);
    /* FIXME massive hack */
    if (compiler->loop_counter == 0) {
      compiler->error = FALSE;
      compiler->result = ORC_COMPILE_RESULT_OK;
    }
  }
}

void
orc_compiler_rewrite_vars2 (OrcCompiler *compiler)
{
  int i;
  int j;
  int k;

  for(j=0;j<compiler->n_insns;j++){
#if 1
    /* must be true to chain src1 to dest:
     *  - rule must handle it
     *  - src1 must be last_use
     *  - only one dest
     */
    if (!(compiler->insns[j].opcode->flags & ORC_STATIC_OPCODE_ACCUMULATOR)
        && compiler->insns[j].opcode->dest_size[1] == 0) {
      int src1 = compiler->insns[j].src_args[0];
      int dest = compiler->insns[j].dest_args[0];

      if (compiler->vars[src1].last_use == j) {
        if (compiler->vars[src1].first_use == j) {
          k = orc_compiler_allocate_register (compiler, TRUE);
          compiler->vars[src1].alloc = k;
        }
        compiler->alloc_regs[compiler->vars[src1].alloc]++;
        compiler->vars[dest].alloc = compiler->vars[src1].alloc;
      }
    }
#endif

    if (0) {
      /* immediate operand, don't load */
      int src2 = compiler->insns[j].src_args[1];
      compiler->vars[src2].alloc = 1;
    } else {
      int src2 = compiler->insns[j].src_args[1];
      if (compiler->vars[src2].alloc == 1) {
        compiler->vars[src2].alloc = 0;
      }
    }

    for(i=0;i<ORC_N_VARIABLES;i++){
      if (compiler->vars[i].name == NULL) continue;
      if (compiler->vars[i].first_use == j) {
        if (compiler->vars[i].alloc) continue;
        k = orc_compiler_allocate_register (compiler, TRUE);
        compiler->vars[i].alloc = k;
      }
    }
    for(i=0;i<ORC_N_VARIABLES;i++){
      if (compiler->vars[i].name == NULL) continue;
      if (compiler->vars[i].last_use == j) {
        compiler->alloc_regs[compiler->vars[i].alloc]--;
      }
    }
  }

}

int
orc_compiler_dup_temporary (OrcCompiler *compiler, int var, int j)
{
  int i = ORC_VAR_T1 + compiler->n_temp_vars + compiler->n_dup_vars;

  compiler->vars[i].vartype = ORC_VAR_TYPE_TEMP;
  compiler->vars[i].size = compiler->vars[var].size;
  compiler->vars[i].name = malloc (strlen(compiler->vars[var].name) + 10);
  sprintf(compiler->vars[i].name, "%s.dup%d", compiler->vars[var].name, j);
  compiler->n_dup_vars++;

  return i;
}

void
orc_compiler_dump_asm (OrcCompiler *compiler)
{
  printf("%s", compiler->asm_code);
}

/**
 * orc_compiler_append_code:
 * @p: an OrcCompiler object
 * @fmt: a printf-style format string
 * @...: optional printf-style arguments
 *
 * Generates a string using sprintf() on the given format and
 * arguments, and appends that string to the generated assembly
 * code for the compiler.
 *
 * This function is used by the ORC_ASM_CODE() macro.
 *
 * This function is useful in a function implementing an OrcRule
 * or implementing a target.
 */
void
orc_compiler_append_code (OrcCompiler *p, const char *fmt, ...)
{
  char tmp[200];
  va_list varargs;
  int n;

  va_start (varargs, fmt);
  vsnprintf(tmp, 200 - 1, fmt, varargs);
  va_end (varargs);

  n = strlen (tmp);
  p->asm_code = realloc (p->asm_code, p->asm_code_len + n + 1);
  memcpy (p->asm_code + p->asm_code_len, tmp, n + 1);
  p->asm_code_len += n;
}

int
orc_compiler_label_new (OrcCompiler *compiler)
{
  return compiler->n_labels++;
}

void
orc_compiler_load_constant (OrcCompiler *compiler, int reg, int size,
    int value)
{
  compiler->target->load_constant (compiler, reg, size, value);
}

int
orc_compiler_get_constant (OrcCompiler *compiler, int size, int value)
{
  int i;

  if (size < 4) {
    if (size < 2) {
      value &= 0xff;
      value |= (value<<8);
    }
    value &= 0xffff;
    value |= (value<<16);
  }

  for(i=0;i<compiler->n_constants;i++){
    if (compiler->constants[i].value == value) {
      break;
    }
  }
  if (i == compiler->n_constants) {
    compiler->n_constants++;
    compiler->constants[i].value = value;
    compiler->constants[i].alloc_reg = 0;
    compiler->constants[i].use_count = 0;
  }

  compiler->constants[i].use_count++;

  if (compiler->constants[i].alloc_reg != 0) {;
    return compiler->constants[i].alloc_reg;
  }
  orc_compiler_load_constant (compiler, compiler->tmpreg, size, value);
  return compiler->tmpreg;
}