/*
* Copyright 2008 Google Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License"); you may not
* use this file except in compliance with the License. You may obtain a copy of
* the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
* License for the specific language governing permissions and limitations under
* the License.
*/
package com.google.gwt.lang;
/**
* Implements a Java <code>long</code> in a way that can be translated to
* JavaScript and could handle numbers needs more than 44 bits.
*/
class BigLongLib extends BigLongLibBase {
static class Const {
static final BigLong MAX_VALUE = create(MASK, MASK, MASK_2 >> 1);
static final BigLong MIN_VALUE = create(0, 0, SIGN_BIT_VALUE);
static final BigLong ONE = fromInt(1);
static final BigLong TWO = fromInt(2);
static final BigLong ZERO = fromInt(0);
}
public static BigLong add(BigLong a, BigLong b) {
int sum0 = getL(a) + getL(b);
int sum1 = getM(a) + getM(b) + (sum0 >> BITS);
int sum2 = getH(a) + getH(b) + (sum1 >> BITS);
return create(sum0 & MASK, sum1 & MASK, sum2 & MASK_2);
}
public static BigLong and(BigLong a, BigLong b) {
return create(getL(a) & getL(b), getM(a) & getM(b), getH(a) & getH(b));
}
public static double compare(BigLong a, BigLong b) {
int signA = sign(a);
int signB = sign(b);
if (signA != signB) {
return signB - signA;
}
int a2 = getH(a);
int b2 = getH(b);
if (a2 != b2) {
return a2 - b2;
}
int a1 = getM(a);
int b1 = getM(b);
if (a1 != b1) {
return a1 - b1;
}
int a0 = getL(a);
int b0 = getL(b);
return a0 - b0;
}
public static BigLong div(BigLong a, BigLong b) {
return divMod(a, b, false);
}
public static BigLong fromDouble(double value) {
if (Double.isNaN(value)) {
return Const.ZERO;
}
if (value < -TWO_PWR_63_DBL) {
return Const.MIN_VALUE;
}
if (value >= TWO_PWR_63_DBL) {
return Const.MAX_VALUE;
}
boolean negative = false;
if (value < 0) {
negative = true;
value = -value;
}
int a2 = 0;
if (value >= TWO_PWR_44_DBL) {
a2 = (int) (value / TWO_PWR_44_DBL);
value -= a2 * TWO_PWR_44_DBL;
}
int a1 = 0;
if (value >= TWO_PWR_22_DBL) {
a1 = (int) (value / TWO_PWR_22_DBL);
value -= a1 * TWO_PWR_22_DBL;
}
int a0 = (int) value;
BigLong result = create(a0, a1, a2);
if (negative) {
negate(result);
}
return result;
}
public static BigLong fromInt(int value) {
return create(value);
}
public static long[] getAsLongArray(long l) {
long[] a = new long[3];
a[0] = (int) (l & MASK);
a[1] = (int) ((l >> BITS) & MASK);
a[2] = (int) ((l >> BITS01) & MASK_2);
return a;
}
public static BigLong mod(BigLong a, BigLong b) {
divMod(a, b, true);
return remainder;
}
// Assumes BITS == 22
public static BigLong mul(BigLong a, BigLong b) {
// Grab 13-bit chunks
int a0 = getL(a) & 0x1fff;
int a1 = (getL(a) >> 13) | ((getM(a) & 0xf) << 9);
int a2 = (getM(a) >> 4) & 0x1fff;
int a3 = (getM(a) >> 17) | ((getH(a) & 0xff) << 5);
int a4 = (getH(a) & 0xfff00) >> 8;
int b0 = getL(b) & 0x1fff;
int b1 = (getL(b) >> 13) | ((getM(b) & 0xf) << 9);
int b2 = (getM(b) >> 4) & 0x1fff;
int b3 = (getM(b) >> 17) | ((getH(b) & 0xff) << 5);
int b4 = (getH(b) & 0xfff00) >> 8;
// Compute partial products
// Optimization: if b is small, avoid multiplying by parts that are 0
int p0 = a0 * b0; // << 0
int p1 = a1 * b0; // << 13
int p2 = a2 * b0; // << 26
int p3 = a3 * b0; // << 39
int p4 = a4 * b0; // << 52
if (b1 != 0) {
p1 += a0 * b1;
p2 += a1 * b1;
p3 += a2 * b1;
p4 += a3 * b1;
}
if (b2 != 0) {
p2 += a0 * b2;
p3 += a1 * b2;
p4 += a2 * b2;
}
if (b3 != 0) {
p3 += a0 * b3;
p4 += a1 * b3;
}
if (b4 != 0) {
p4 += a0 * b4;
}
// Accumulate into 22-bit chunks:
// .........................................c10|...................c00|
// |....................|..................xxxx|xxxxxxxxxxxxxxxxxxxxxx| p0
// |....................|......................|......................|
// |....................|...................c11|......c01.............|
// |....................|....xxxxxxxxxxxxxxxxxx|xxxxxxxxx.............| p1
// |....................|......................|......................|
// |.................c22|...............c12....|......................|
// |..........xxxxxxxxxx|xxxxxxxxxxxxxxxxxx....|......................| p2
// |....................|......................|......................|
// |.................c23|..c13.................|......................|
// |xxxxxxxxxxxxxxxxxxxx|xxxxx.................|......................| p3
// |....................|......................|......................|
// |.........c24........|......................|......................|
// |xxxxxxxxxxxx........|......................|......................| p4
int c00 = p0 & 0x3fffff;
int c01 = (p1 & 0x1ff) << 13;
int c0 = c00 + c01;
int c10 = p0 >> 22;
int c11 = p1 >> 9;
int c12 = (p2 & 0x3ffff) << 4;
int c13 = (p3 & 0x1f) << 17;
int c1 = c10 + c11 + c12 + c13;
int c22 = p2 >> 18;
int c23 = p3 >> 5;
int c24 = (p4 & 0xfff) << 8;
int c2 = c22 + c23 + c24;
// Propagate high bits from c0 -> c1, c1 -> c2
c1 += c0 >> BITS;
c0 &= MASK;
c2 += c1 >> BITS;
c1 &= MASK;
c2 &= MASK_2;
return create(c0, c1, c2);
}
public static BigLong neg(BigLong a) {
int neg0 = (~getL(a) + 1) & MASK;
int neg1 = (~getM(a) + (neg0 == 0 ? 1 : 0)) & MASK;
int neg2 = (~getH(a) + ((neg0 == 0 && neg1 == 0) ? 1 : 0)) & MASK_2;
return create(neg0, neg1, neg2);
}
public static BigLong not(BigLong a) {
return create((~getL(a)) & MASK, (~getM(a)) & MASK, (~getH(a)) & MASK_2);
}
public static BigLong or(BigLong a, BigLong b) {
return create(getL(a) | getL(b), getM(a) | getM(b), getH(a) | getH(b));
}
public static BigLong shl(BigLong a, int n) {
n &= 63;
int res0, res1, res2;
if (n < BITS) {
res0 = getL(a) << n;
res1 = (getM(a) << n) | (getL(a) >> (BITS - n));
res2 = (getH(a) << n) | (getM(a) >> (BITS - n));
} else if (n < BITS01) {
res0 = 0;
res1 = getL(a) << (n - BITS);
res2 = (getM(a) << (n - BITS)) | (getL(a) >> (BITS01 - n));
} else {
res0 = 0;
res1 = 0;
res2 = getL(a) << (n - BITS01);
}
return create(res0 & MASK, res1 & MASK, res2 & MASK_2);
}
public static BigLong shr(BigLong a, int n) {
n &= 63;
int res0, res1, res2;
// Sign extend h(a)
int a2 = getH(a);
boolean negative = (a2 & SIGN_BIT_VALUE) != 0;
if (negative) {
a2 |= ~MASK_2;
}
if (n < BITS) {
res2 = a2 >> n;
res1 = (getM(a) >> n) | (a2 << (BITS - n));
res0 = (getL(a) >> n) | (getM(a) << (BITS - n));
} else if (n < BITS01) {
res2 = negative ? MASK_2 : 0;
res1 = a2 >> (n - BITS);
res0 = (getM(a) >> (n - BITS)) | (a2 << (BITS01 - n));
} else {
res2 = negative ? MASK_2 : 0;
res1 = negative ? MASK : 0;
res0 = a2 >> (n - BITS01);
}
return create(res0 & MASK, res1 & MASK, res2 & MASK_2);
}
/**
* Logical right shift. It does not preserve the sign of the input.
*/
public static BigLong shru(BigLong a, int n) {
n &= 63;
int res0, res1, res2;
int a2 = getH(a) & MASK_2;
if (n < BITS) {
res2 = a2 >>> n;
res1 = (getM(a) >> n) | (a2 << (BITS - n));
res0 = (getL(a) >> n) | (getM(a) << (BITS - n));
} else if (n < BITS01) {
res2 = 0;
res1 = a2 >>> (n - BITS);
res0 = (getM(a) >> (n - BITS)) | (getH(a) << (BITS01 - n));
} else {
res2 = 0;
res1 = 0;
res0 = a2 >>> (n - BITS01);
}
return create(res0 & MASK, res1 & MASK, res2 & MASK_2);
}
public static BigLong sub(BigLong a, BigLong b) {
int sum0 = getL(a) - getL(b);
int sum1 = getM(a) - getM(b) + (sum0 >> BITS);
int sum2 = getH(a) - getH(b) + (sum1 >> BITS);
return create(sum0 & MASK, sum1 & MASK, sum2 & MASK_2);
}
public static double toDouble(BigLong a) {
if (BigLongLib.compare(a, Const.ZERO) < 0) {
return -toDoubleHelper(BigLongLib.neg(a));
}
return toDoubleHelper(a);
}
// Assumes Integer.MIN_VALUE <= a <= Integer.MAX_VALUE
public static int toInt(BigLong a) {
return getL(a) | (getM(a) << BITS);
}
public static String toString(BigLong a) {
if (BigLongLibBase.isZero(a)) {
return "0";
}
if (BigLongLibBase.isMinValue(a)) {
// Special-case MIN_VALUE because neg(MIN_VALUE) == MIN_VALUE
return "-9223372036854775808";
}
if (BigLongLibBase.isNegative(a)) {
return "-" + toString(neg(a));
}
BigLong rem = a;
String res = "";
while (!BigLongLibBase.isZero(rem)) {
// Do several digits each time through the loop, so as to
// minimize the calls to the very expensive emulated div.
final int tenPowerZeroes = 9;
final int tenPower = 1000000000;
BigLong tenPowerLong = fromInt(tenPower);
rem = divMod(rem, tenPowerLong, true);
String digits = "" + toInt(BigLongLibBase.remainder);
if (!BigLongLibBase.isZero(rem)) {
int zeroesNeeded = tenPowerZeroes - digits.length();
for (; zeroesNeeded > 0; zeroesNeeded--) {
digits = "0" + digits;
}
}
res = digits + res;
}
return res;
}
public static BigLong xor(BigLong a, BigLong b) {
return create(getL(a) ^ getL(b), getM(a) ^ getM(b), getH(a) ^ getH(b));
}
/**
* Not instantiable.
*/
private BigLongLib() {
}
}