Function codeeq

lua/src/lcode.c:1540–1565

** Emit code for equality comparisons ('==', '~='). ** 'e1' was already put as RK by 'luaK_infix'. */

** 'e1' was already put as RK by 'luaK_infix'.
*/
static void codeeq (FuncState *fs, BinOpr opr, expdesc *e1, expdesc *e2) {
  int r1, r2;
  int im;
  int isfloat = 0;  /* not needed here, but kept for symmetry */
  OpCode op;
  if (e1->k != VNONRELOC) {
    lua_assert(e1->k == VK || e1->k == VKINT || e1->k == VKFLT);
    swapexps(e1, e2);
  }
  r1 = luaK_exp2anyreg(fs, e1);  /* 1st expression must be in register */
  if (isSCnumber(e2, &im, &isfloat)) {
    op = OP_EQI;
    r2 = im;  /* immediate operand */
  }
  else if (luaK_exp2RK(fs, e2)) {  /* 1st expression is constant? */
    op = OP_EQK;
    r2 = e2->u.info;  /* constant index */
  }
  else {
    op = OP_EQ;  /* will compare two registers */
    r2 = luaK_exp2anyreg(fs, e2);
  }
  freeexps(fs, e1, e2);
  e1->u.info = condjump(fs, op, r1, r2, isfloat, (opr == OPR_EQ));
  e1->k = VJMP;
}


/*