Function decFloatFromPackedChecked

extern/decNumber/decCommon.c:708–752

------------------------------------------------------------------ */ decFloatFromPackedChecked -- set from exponent and packed; checked */ / df is the target decFloat */ exp is the in-range unbiased exponent, q, or a special value in */ the form returned by decFloatGetExponent */ packed holds DECPMAX packed decimal digits plus a sig

/* No status will be set.                                             */
/* ------------------------------------------------------------------ */
decFloat * decFloatFromPackedChecked(decFloat *df, Int exp,
                                     const uByte *packed) {
  uByte bcdar[DECPMAX+2];               // work [+1 for pad, +1 for sign]
  const uByte *ip;                      // ..
  uByte *op;                            // ..
  Int   sig=0;                          // sign

  // expand coefficient and sign to BCDAR
  #if SINGLE
  op=bcdar+1;                           // no pad digit
  #else
  op=bcdar;                             // first (pad) digit here
  #endif
  for (ip=packed; ip<packed+((DECPMAX+2)/2); ip++) {
    *op=*ip>>4;
    if (*op>9) return NULL;
    op++;
    *op=(uByte)(*ip&0x0f);              // [final nibble is sign]
    if (*op>9 && ip<packed+((DECPMAX+2)/2)-1) return NULL;
    op++;
    }
  op--;                                 // -> sign byte
  if (*op<=9) return NULL;              // bad sign
  if (*op==DECPMINUS || *op==DECPMINUSALT) sig=DECFLOAT_Sign;

  #if !SINGLE
  if (bcdar[0]!=0) return NULL;         // bad pad nibble
  #endif

  if (EXPISNAN(exp)) {                  // a NaN
    if (bcdar[1]!=0) return NULL;       // bad msd
    } // NaN
   else if (EXPISINF(exp)) {            // is infinite
    Int i;
    for (i=0; i<DECPMAX; i++) {
      if (bcdar[i+1]!=0) return NULL;   // should be all zeros
      }
    } // infinity
   else {                               // finite
    // check the exponent is in range
    if (exp>DECEMAX-DECPMAX+1) return NULL;
    if (exp<DECEMIN-DECPMAX+1) return NULL;
    }
  return decFloatFromBCD(df, exp, bcdar+1, sig);
  } // decFloatFromPacked

/* ------------------------------------------------------------------ */
/* decFloatFromString -- conversion from numeric string               */