function biBarrettMu($m)
{
$this->modulus = biCopy($m);
$this->k = biHighIndex($this->modulus) + 1;
$b2k = new BigInt();
$b2k->digits[2 * $this->k] = 1;
// b2k = b^(2k)
$this->mu = biDivide($b2k, $this->modulus);
$this->bkplus1 = new BigInt();
$this->bkplus1->digits[$this->k + 1] = 1;
// bkplus1 = b^(k+1)
//$this->modulo = BarrettMu_modulo;
//$this->multiplyMod = BarrettMu_multiplyMod;
//this.powMod = BarrettMu_powMod;
}
function biDivideModulo($x, $y)
{
global $biRadixBase, $biRadixBits, $biBitsPerDigit, $biRadix, $biHalfRadix, $biRadixSquared, $biMaxDigitVal, $biMaxInteger, $biMaxDigits, $biZERO_ARRAY, $biBigZero, $biBigOne, $dpl10, $lr10;
$nb = biNumBits($x);
$nh = biHighIndex($x);
$tb = biNumBits($y);
$th = biHighIndex($y);
$origXIsNeg = $x->isNeg ? 1 : 0;
$origYIsNeg = $y->isNeg ? 1 : 0;
$origX = $x;
$origY = $y;
$q;
$r;
if ($nb < $tb || $nb == $tb && biCompareModule($x, $y) < 0) {
// |x| < |y|
if ($x->isNeg && $y->isNeg xor !$x->isNeg && !$y->isNeg) {
$q = new BigInt();
$r = biCopy($x);
} else {
$q = new BigInt();
$q->digits[0] = 1;
$q->isNeg = 1;
$r = biAdd($y, $x);
}
return array($q, $r);
}
$q = new BigInt();
$x = biCopy($x);
$x->isNeg = 0;
$r = $x;
$y = biCopy($y);
$y->isNeg = 0;
// Normalize Y.
$t = ceil($tb / $biBitsPerDigit) - 1;
$lambda = 0;
while ($y->digits[$t] < $biHalfRadix) {
$y = biShiftLeft($y, 1);
++$lambda;
++$tb;
$t = intval(ceil($tb / $biBitsPerDigit)) - 1;
}
// Shift r over to keep the quotient constant. We'll shift the
// remainder back at the end.
$r = biShiftLeft($r, $lambda);
$nb += $lambda;
// Update the bit count for x.
$n = intval(ceil($nb / $biBitsPerDigit)) - 1;
$b = biMultiplyByRadixPower($y, $n - $t);
while (biCompare($r, $b) != -1) {
$q->digits[$n - $t] += 1;
$r = biSubtract($r, $b);
}
for ($i = $n; $i > $t; --$i) {
$ri = $i >= count($r->digits) ? 0 : $r->digits[$i];
$ri1 = $i - 1 >= count($r->digits) ? 0 : $r->digits[$i - 1];
$ri2 = $i - 2 >= count($r->digits) || $i - 2 < 0 ? 0 : $r->digits[$i - 2];
$yt = $t >= count($y->digits) ? 0 : $y->digits[$t];
$yt1 = $t - 1 >= count($y->digits) || $t - 1 < 0 ? 0 : $y->digits[$t - 1];
if ($ri == $yt) {
$q->digits[$i - $t - 1] = $biMaxDigitVal;
} else {
$q->digits[$i - $t - 1] = intval(floor(($ri * $biRadix + $ri1) / $yt));
}
$c1 = $q->digits[$i - $t - 1] * ($yt * $biRadix + $yt1);
$c2 = $ri * $biRadixSquared + ($ri1 * $biRadix + $ri2);
while ($c1 > $c2) {
$q->digits[$i - $t - 1] -= 1;
$c1 = $q->digits[$i - $t - 1] * ($yt * $biRadix | $yt1);
$c2 = $ri * $biRadix * $biRadix + ($ri1 * $biRadix + $ri2);
}
$b = biMultiplyByRadixPower($y, $i - $t - 1);
$r = biSubtract($r, biMultiplyDigit($b, $q->digits[$i - $t - 1]));
if ($r->isNeg) {
$r = biAdd($r, $b);
$q->digits[$i - $t - 1] -= 1;
}
}
$r = biShiftRight($r, $lambda);
// Fiddle with the signs and stuff to make sure that 0 <= r < y.
/*$q->isNeg = ($x->isNeg != $origYIsNeg) ? 1 : 0;
if ($x->isNeg) {
if ($origYIsNeg) {
$q = biAdd($q, $biBigOne);
} else {
$q = biSubtract($q, $biBigOne);
}
$y = biShiftRight($y, $lambda);
$r = biSubtract($y, $r);
}*/
// Check for the unbelievably stupid degenerate case of r == -0.
/*
$origXIsNeg = $x->isNeg ? 1 : 0;
$origYIsNeg = $y->isNeg ? 1 : 0;
if ($nb < $tb || ($nb == $tb && biCompareModule($x, $y) < 0)) {
// |x| < |y|
if (($x->isNeg && $y->isNeg) xor (!$x->isNeg && !$y->isNeg)){
$q = new BigInt();
$r= biCopy($x);
}else {
$q = new BigInt();
$q->digits[0] = 1;
$q->isNeg = 1;
$r = biAdd($y, $x);
}
return array($q, $r);
}
*/
if (!$origXIsNeg && !$origYIsNeg) {
return array($q, $r);
} elseif ($origXIsNeg && $origYIsNeg) {
$r->isNeg = 1;
return array($q, $r);
} else {
$q->isNeg = 1;
$q = biSubtract($q, $biBigOne);
$r->isNeg = $origXIsNeg;
$r = biAdd($r, $origY);
}
if ($r->digits[0] == 0 && biHighIndex($r) == 0) {
$r->isNeg = 0;
}
return array($q, $r);
}
