public function ParagonIE_Sodium_Core32_Int64::mulInt64 in Automatic Updates 7

Same name and namespace in other branches

1. 8 vendor/paragonie/sodium_compat/src/Core32/Int64.php \ParagonIE_Sodium_Core32_Int64::mulInt64()

@psalm-suppress MixedAssignment

Parameters

ParagonIE_Sodium_Core32_Int64 $int:

int $size:

Return value

ParagonIE_Sodium_Core32_Int64

Throws

SodiumException

TypeError

File

vendor/paragonie/sodium_compat/src/Core32/Int64.php, line 467

Class

ParagonIE_Sodium_Core32_Int64

Class ParagonIE_Sodium_Core32_Int64

Code

public function mulInt64(ParagonIE_Sodium_Core32_Int64 $int, $size = 0) {
  if (ParagonIE_Sodium_Compat::$fastMult) {
    return $this
      ->mulInt64Fast($int);
  }
  ParagonIE_Sodium_Core32_Util::declareScalarType($size, 'int', 2);
  if (!$size) {
    $size = 63;
  }
  list($a, $b) = self::ctSelect($this, $int);
  $return = new ParagonIE_Sodium_Core32_Int64();
  $return->unsignedInt = $this->unsignedInt;

  // Initialize:
  $ret0 = 0;
  $ret1 = 0;
  $ret2 = 0;
  $ret3 = 0;
  $a0 = $a->limbs[0];
  $a1 = $a->limbs[1];
  $a2 = $a->limbs[2];
  $a3 = $a->limbs[3];
  $b0 = $b->limbs[0];
  $b1 = $b->limbs[1];
  $b2 = $b->limbs[2];
  $b3 = $b->limbs[3];

  /** @var int $size */

  /** @var int $i */
  for ($i = (int) $size; $i >= 0; --$i) {
    $mask = -($b3 & 1);
    $x0 = $a0 & $mask;
    $x1 = $a1 & $mask;
    $x2 = $a2 & $mask;
    $x3 = $a3 & $mask;
    $ret3 += $x3;
    $c = $ret3 >> 16;
    $ret2 += $x2 + $c;
    $c = $ret2 >> 16;
    $ret1 += $x1 + $c;
    $c = $ret1 >> 16;
    $ret0 += $x0 + $c;
    $ret0 &= 0xffff;
    $ret1 &= 0xffff;
    $ret2 &= 0xffff;
    $ret3 &= 0xffff;
    $a3 = $a3 << 1;
    $x3 = $a3 >> 16;
    $a2 = $a2 << 1 | $x3;
    $x2 = $a2 >> 16;
    $a1 = $a1 << 1 | $x2;
    $x1 = $a1 >> 16;
    $a0 = $a0 << 1 | $x1;
    $a0 &= 0xffff;
    $a1 &= 0xffff;
    $a2 &= 0xffff;
    $a3 &= 0xffff;
    $x0 = ($b0 & 1) << 16;
    $x1 = ($b1 & 1) << 16;
    $x2 = ($b2 & 1) << 16;
    $b0 = $b0 >> 1;
    $b1 = ($b1 | $x0) >> 1;
    $b2 = ($b2 | $x1) >> 1;
    $b3 = ($b3 | $x2) >> 1;
    $b0 &= 0xffff;
    $b1 &= 0xffff;
    $b2 &= 0xffff;
    $b3 &= 0xffff;
  }
  $return->limbs[0] = $ret0;
  $return->limbs[1] = $ret1;
  $return->limbs[2] = $ret2;
  $return->limbs[3] = $ret3;
  return $return;
}