Improve double to string conversion

This commit is contained in:
Alexey Andreev 2018-12-02 01:28:43 +03:00
parent 1cf3cce076
commit f23c71cd97
16 changed files with 412 additions and 67 deletions

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@ -0,0 +1,197 @@
/*
* Copyright 2018 Alexey Andreev.
*
* 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 org.teavm.classlib.impl.text;
import java.util.Arrays;
public final class DoubleAnalyzer {
private DoubleAnalyzer() {
}
private static final int MAX_ABS_DEC_EXP = 330;
public static final int DECIMAL_PRECISION = 18;
public static final long DOUBLE_MAX_POS = 100000000000000000L;
private static long[] mantissa10Table = new long[MAX_ABS_DEC_EXP * 2];
private static int[] exp10Table = new int[MAX_ABS_DEC_EXP * 2];
static {
long decimalMantissaOne = 8000000000000000000L;
long mantissa = decimalMantissaOne;
long remainder = 0;
int exponent = 1023;
for (int i = 0; i < MAX_ABS_DEC_EXP; ++i) {
mantissa10Table[i + MAX_ABS_DEC_EXP] = Long.divideUnsigned(mantissa, 80);
exp10Table[i + MAX_ABS_DEC_EXP] = exponent;
mantissa = Long.divideUnsigned(mantissa, 10);
remainder = Long.remainderUnsigned(mantissa, 10);
while (mantissa <= decimalMantissaOne && (mantissa & (1L << 63)) == 0) {
mantissa <<= 1;
exponent++;
remainder <<= 1;
}
mantissa += remainder / 10;
}
long maxMantissa = Long.MAX_VALUE / 10;
mantissa = decimalMantissaOne;
exponent = 1023;
for (int i = 0; i < MAX_ABS_DEC_EXP; ++i) {
long nextMantissa = mantissa;
int shift = 0;
while (nextMantissa > maxMantissa) {
nextMantissa >>= 1;
shift++;
exponent--;
}
nextMantissa *= 10;
if (shift > 0) {
long shiftedOffPart = mantissa & ((1 << shift) - 1);
nextMantissa += (shiftedOffPart * 10) >> shift;
}
mantissa = nextMantissa;
mantissa10Table[MAX_ABS_DEC_EXP - i - 1] = Long.divideUnsigned(mantissa, 80);
exp10Table[MAX_ABS_DEC_EXP - i - 1] = exponent;
}
}
public static void analyze(double d, Result result) {
long bits = Double.doubleToLongBits(d);
result.sign = (bits & (1L << 63)) != 0;
long mantissa = bits & ((1L << 52) - 1);
int exponent = (int) (bits >> 52) & ((1 << 11) - 1);
if (mantissa == 0 && exponent == 0) {
result.mantissa = 0;
result.exponent = 0;
return;
}
int errorShift = 0;
if (exponent == 0) {
mantissa <<= 1;
while ((mantissa & (1L << 52)) == 0) {
mantissa <<= 1;
exponent--;
++errorShift;
}
} else {
mantissa |= 1L << 52;
}
int decExponent = Arrays.binarySearch(exp10Table, exponent);
if (decExponent < 0) {
decExponent = -decExponent - 2;
}
int binExponentCorrection = exponent - exp10Table[decExponent];
int mantissaShift = 12 + binExponentCorrection;
long decMantissa = mulAndShiftRight(mantissa, mantissa10Table[decExponent], mantissaShift);
if (decMantissa >= 1000000000000000000L) {
++decExponent;
binExponentCorrection = exponent - exp10Table[decExponent];
mantissaShift = 12 + binExponentCorrection;
decMantissa = mulAndShiftRight(mantissa, mantissa10Table[decExponent], mantissaShift);
}
long error = mantissa10Table[decExponent] >>> (63 - mantissaShift - errorShift);
long upError = (error + 1) >> 1;
long downError = error >> 1;
if (mantissa == (1L << 52)) {
downError >>= 2;
}
long lowerPos = findLowerDistanceToZero(decMantissa, downError);
long upperPos = findUpperDistanceToZero(decMantissa, upError);
if (lowerPos > upperPos) {
decMantissa = (decMantissa / lowerPos) * lowerPos;
} else if (lowerPos < upperPos) {
decMantissa = (decMantissa / upperPos) * upperPos + upperPos;
} else {
decMantissa = ((decMantissa + upperPos / 2) / upperPos) * upperPos;
}
if (decMantissa >= 1000000000000000000L) {
decExponent++;
decMantissa /= 10;
}
result.mantissa = decMantissa;
result.exponent = decExponent - MAX_ABS_DEC_EXP;
}
private static long findLowerDistanceToZero(long mantissa, long error) {
long pos = 10;
while (pos <= error) {
pos *= 10;
}
long mantissaRight = mantissa % pos;
if (mantissaRight >= error / 2) {
pos /= 10;
}
return pos;
}
private static long findUpperDistanceToZero(long mantissa, long error) {
long pos = 1;
while (pos <= error) {
pos *= 10;
}
long mantissaRight = mantissa % pos;
if (pos - mantissaRight > error / 2) {
pos /= 10;
}
return pos;
}
// Multiply two longs and shft result right by 64-shift bits.
private static long mulAndShiftRight(long a, long b, int shift) {
long a1 = a & 0xFFFF;
long a2 = (a >>> 16) & 0xFFFF;
long a3 = (a >>> 32) & 0xFFFF;
long a4 = (a >>> 48) & 0xFFFF;
long b1 = b & 0xFFFF;
long b2 = (b >>> 16) & 0xFFFF;
long b3 = (b >>> 32) & 0xFFFF;
long b4 = (b >>> 48) & 0xFFFF;
long cm = b3 * a1 + b2 * a2 + b1 * a3;
long c0 = b4 * a1 + b3 * a2 + b2 * a3 + b1 * a4;
long c1 = b4 * a2 + b3 * a3 + b2 * a4;
long c2 = b4 * a3 + b3 * a4;
long c3 = b4 * a4;
long c = (c3 << (32 + shift)) + (c2 << (16 + shift)) + (c1 << shift);
if (shift <= 16) {
c += c0 >>> (16 - shift);
} else {
c += c0 << (shift - 16);
}
c += cm >>> (32 - shift);
return c;
}
public static class Result {
public long mantissa;
public int exponent;
public boolean sign;
}
}

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@ -28,6 +28,17 @@ public class LongNativeGenerator implements Generator {
case "compare":
writer.append("return Long_compare(").append(context.getParameterName(1)).append(", ")
.append(context.getParameterName(2)).append(");").softNewLine();
context.useLongLibrary();
break;
case "divideUnsigned":
writer.append("return Long_udiv(").append(context.getParameterName(1)).append(", ")
.append(context.getParameterName(2)).append(");").softNewLine();
context.useLongLibrary();
break;
case "remainderUnsigned":
writer.append("return Long_urem(").append(context.getParameterName(1)).append(", ")
.append(context.getParameterName(2)).append(");").softNewLine();
context.useLongLibrary();
break;
}
}

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@ -15,31 +15,27 @@
*/
package org.teavm.classlib.java.lang;
import org.teavm.classlib.impl.text.DoubleAnalyzer;
import org.teavm.classlib.java.io.TSerializable;
import org.teavm.classlib.java.util.TArrays;
class TAbstractStringBuilder extends TObject implements TSerializable, TCharSequence {
static class Constants {
private static float[] powersOfTen = { 1E1f, 1E2f, 1E4f, 1E8f, 1E16f, 1E32f };
private static double[] doublePowersOfTen = { 1E1, 1E2, 1E4, 1E8, 1E16, 1E32, 1E64, 1E128, 1E256 };
private static float[] negPowersOfTen = { 1E-1f, 1E-2f, 1E-4f, 1E-8f, 1E-16f, 1E-32f };
private static double[] negDoublePowersOfTen = { 1E-1, 1E-2, 1E-4, 1E-8, 1E-16, 1E-32,
1E-64, 1E-128, 1E-256 };
private static int[] intPowersOfTen = { 1, 10, 100, 1000, 10000, 100000, 1000000, 10000000, 100000000,
static float[] powersOfTen = { 1E1f, 1E2f, 1E4f, 1E8f, 1E16f, 1E32f };
static float[] negPowersOfTen = { 1E-1f, 1E-2f, 1E-4f, 1E-8f, 1E-16f, 1E-32f };
static int[] intPowersOfTen = { 1, 10, 100, 1000, 10000, 100000, 1000000, 10000000, 100000000,
1000000000 };
private static long[] longPowersOfTen = { 1, 10, 100, 1000, 10000, 100000, 1000000, 10000000, 100000000,
static long[] longPowersOfTen = { 1, 10, 100, 1000, 10000, 100000, 1000000, 10000000, 100000000,
1000000000, 10000000000L, 100000000000L, 1000000000000L, 10000000000000L, 100000000000000L,
1000000000000000L, 10000000000000000L, 100000000000000000L, 1000000000000000000L };
private static final long[] longLogPowersOfTen = { 1, 10, 100, 10000, 100000000, 10000000000000000L, };
static final long[] longLogPowersOfTen = { 1, 10, 100, 10000, 100000000, 10000000000000000L, };
private static final int FLOAT_DECIMAL_PRECISION = 7;
private static final int DOUBLE_DECIMAL_PRECISION = 16;
private static final float FLOAT_DECIMAL_FACTOR = 1E6f;
private static final double DOUBLE_DECIMAL_FACTOR = 1E15;
private static final int FLOAT_MAX_EXPONENT = 38;
private static final int DOUBLE_MAX_EXPONENT = 308;
private static final int FLOAT_MAX_POS = 1000000;
private static final long DOUBLE_MAX_POS = 1000000000000000L;
static final int FLOAT_DECIMAL_PRECISION = 7;
static final float FLOAT_DECIMAL_FACTOR = 1E6f;
static final int FLOAT_MAX_EXPONENT = 38;
static final int FLOAT_MAX_POS = 1000000;
static final DoubleAnalyzer.Result doubleAnalysisResult = new DoubleAnalyzer.Result();
}
char[] buffer;
@ -388,58 +384,22 @@ class TAbstractStringBuilder extends TObject implements TSerializable, TCharSequ
buffer[target++] = 'y';
return this;
}
DoubleAnalyzer.Result number = Constants.doubleAnalysisResult;
DoubleAnalyzer.analyze(value, number);
long mantissa = number.mantissa;
int exp = number.exponent;
boolean negative = number.sign;
int intPart = 1;
// Get absolute value
boolean negative = false;
int sz = 1; // Decimal point always included
if (value < 0) {
negative = true;
value = -value;
if (negative) {
++sz; // including '-' sign of mantissa
}
// Split into decimal mantissa and decimal exponent
int exp = 0;
long mantissa = 0;
int intPart = 1;
int digits = 0;
if (value >= 1) {
int bit = 256;
exp = 0;
double digit = 1;
for (int i = Constants.doublePowersOfTen.length - 1; i >= 0; --i) {
if ((exp | bit) <= Constants.DOUBLE_MAX_EXPONENT && Constants.doublePowersOfTen[i] * digit <= value) {
digit *= Constants.doublePowersOfTen[i];
exp |= bit;
}
bit >>= 1;
}
mantissa = (long) (((value / digit) * Constants.DOUBLE_DECIMAL_FACTOR) + 0.5);
} else {
int bit = 256;
exp = 0;
double digit = 1;
for (int i = Constants.negDoublePowersOfTen.length - 1; i >= 0; --i) {
if ((exp | bit) <= 324 && Constants.negDoublePowersOfTen[i] * digit * 10 > value) {
exp |= bit;
if (exp == 324) {
value /= Constants.negDoublePowersOfTen[i];
} else {
digit *= Constants.negDoublePowersOfTen[i];
}
}
bit >>= 1;
}
exp = -exp;
mantissa = (long) (((value * Constants.DOUBLE_MAX_POS) / digit) + 0.5);
while (mantissa >= 10000000000000000L) {
mantissa /= 10;
exp--;
}
}
// Remove trailing zeros
digits = Constants.DOUBLE_DECIMAL_PRECISION;
int digits = DoubleAnalyzer.DECIMAL_PRECISION;
int zeros = trailingDecimalZeros(mantissa);
if (zeros > 0) {
digits -= zeros;
@ -482,7 +442,7 @@ class TAbstractStringBuilder extends TObject implements TSerializable, TCharSequ
if (negative) {
buffer[target++] = '-';
}
long pos = Constants.DOUBLE_MAX_POS;
long pos = DoubleAnalyzer.DOUBLE_MAX_POS;
for (int i = 0; i < digits; ++i) {
int intDigit;
if (pos > 0) {

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@ -243,9 +243,11 @@ public class TDouble extends TNumber implements TComparable<TDouble> {
}
@InjectedBy(DoubleGenerator.class)
@Import(name = "teavm_reinterpretDoubleToLong")
public static native long doubleToLongBits(double value);
@InjectedBy(DoubleGenerator.class)
@Import(name = "teavm_reinterpretLongToDouble")
public static native double longBitsToDouble(long bits);
public static TString toHexString(double d) {

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@ -247,9 +247,11 @@ public class TFloat extends TNumber implements TComparable<TFloat> {
}
@JSBody(params = "value", script = "return $rt_floatToIntBits(value);")
@Import(name = "teavm_reinterpretFloatToInt")
public static native int floatToIntBits(float value);
@JSBody(params = "bits", script = "return $rt_intBitsToFloat(bits);")
@Import(name = "teavm_reinterpretIntToFloat")
public static native float intBitsToFloat(int bits);
public static TString toHexString(float f) {

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@ -16,6 +16,7 @@
package org.teavm.classlib.java.lang;
import static org.teavm.classlib.impl.IntegerUtil.toUnsignedLogRadixString;
import org.teavm.backend.javascript.spi.GeneratedBy;
public class TLong extends TNumber implements TComparable<TLong> {
public static final long MIN_VALUE = -0x8000000000000000L;
@ -348,4 +349,10 @@ public class TLong extends TNumber implements TComparable<TLong> {
public static int signum(long i) {
return (int) ((i >> 63) | (-i >>> 63));
}
@GeneratedBy(LongNativeGenerator.class)
public static native long divideUnsigned(long dividend, long divisor);
@GeneratedBy(LongNativeGenerator.class)
public static native long remainderUnsigned(long dividend, long divisor);
}

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@ -43,7 +43,7 @@ public final class TSystem extends TObject {
public static TPrintStream out() {
if (outCache == null) {
new TPrintStream(new TConsoleOutputStreamStdout(), false);
outCache = new TPrintStream(new TConsoleOutputStreamStdout(), false);
}
return outCache;
}

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@ -49,6 +49,7 @@ import org.teavm.backend.c.intrinsic.FunctionIntrinsic;
import org.teavm.backend.c.intrinsic.GCIntrinsic;
import org.teavm.backend.c.intrinsic.Intrinsic;
import org.teavm.backend.c.intrinsic.IntrinsicFactory;
import org.teavm.backend.c.intrinsic.LongIntrinsic;
import org.teavm.backend.c.intrinsic.MutatorIntrinsic;
import org.teavm.backend.c.intrinsic.PlatformClassIntrinsic;
import org.teavm.backend.c.intrinsic.PlatformClassMetadataIntrinsic;
@ -234,6 +235,7 @@ public class CTarget implements TeaVMTarget, TeaVMCHost {
intrinsics.add(new ExceptionHandlingIntrinsic());
intrinsics.add(new FunctionIntrinsic(characteristics, exportDependencyListener.getResolvedMethods()));
intrinsics.add(new RuntimeClassIntrinsic());
intrinsics.add(new LongIntrinsic());
List<Generator> generators = new ArrayList<>();
generators.add(new ArrayGenerator());

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@ -0,0 +1,55 @@
/*
* Copyright 2018 Alexey Andreev.
*
* 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 org.teavm.backend.c.intrinsic;
import org.teavm.ast.InvocationExpr;
import org.teavm.model.MethodReference;
public class LongIntrinsic implements Intrinsic {
@Override
public boolean canHandle(MethodReference method) {
if (!method.getClassName().equals(Long.class.getName())) {
return false;
}
switch (method.getName()) {
case "divideUnsigned":
case "remainderUnsigned":
return true;
default:
return false;
}
}
@Override
public void apply(IntrinsicContext context, InvocationExpr invocation) {
switch (invocation.getMethod().getName()) {
case "divideUnsigned":
writeBinary(context, invocation, "/");
break;
case "remainderUnsigned":
writeBinary(context, invocation, "%");
break;
}
}
private void writeBinary(IntrinsicContext context, InvocationExpr invocation, String operation) {
context.writer().print("((int64_t) ((uint64_t) ");
context.emit(invocation.getArguments().get(0));
context.writer().print(" " + operation + " (uint64_t) ");
context.emit(invocation.getArguments().get(1));
context.writer().print("))");
}
}

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@ -1006,6 +1006,11 @@ public class Renderer implements RenderingManager {
public String typeToClassString(ValueType type) {
return context.typeToClsString(type);
}
@Override
public void useLongLibrary() {
longLibraryUsed = true;
}
}
private void appendMonitor(StatementRenderer statementRenderer, MethodNode methodNode) throws IOException {

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@ -43,4 +43,6 @@ public interface GeneratorContext extends ServiceRepository {
Diagnostics getDiagnostics();
String typeToClassString(ValueType type);
void useLongLibrary();
}

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@ -49,6 +49,7 @@ import org.teavm.backend.wasm.intrinsics.ExceptionHandlingIntrinsic;
import org.teavm.backend.wasm.intrinsics.FloatIntrinsic;
import org.teavm.backend.wasm.intrinsics.FunctionIntrinsic;
import org.teavm.backend.wasm.intrinsics.GCIntrinsic;
import org.teavm.backend.wasm.intrinsics.LongIntrinsic;
import org.teavm.backend.wasm.intrinsics.MutatorIntrinsic;
import org.teavm.backend.wasm.intrinsics.ObjectIntrinsic;
import org.teavm.backend.wasm.intrinsics.PlatformClassIntrinsic;
@ -343,6 +344,7 @@ public class WasmTarget implements TeaVMTarget, TeaVMWasmHost {
context.addIntrinsic(new RuntimeClassIntrinsic());
context.addIntrinsic(new FloatIntrinsic());
context.addIntrinsic(new DoubleIntrinsic());
context.addIntrinsic(new LongIntrinsic());
context.addIntrinsic(new ObjectIntrinsic());
context.addGenerator(new ArrayGenerator());

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@ -0,0 +1,56 @@
/*
* Copyright 2018 Alexey Andreev.
*
* 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 org.teavm.backend.wasm.intrinsics;
import org.teavm.ast.InvocationExpr;
import org.teavm.backend.wasm.model.expression.WasmExpression;
import org.teavm.backend.wasm.model.expression.WasmIntBinary;
import org.teavm.backend.wasm.model.expression.WasmIntBinaryOperation;
import org.teavm.backend.wasm.model.expression.WasmIntType;
import org.teavm.model.MethodReference;
public class LongIntrinsic implements WasmIntrinsic {
@Override
public boolean isApplicable(MethodReference methodReference) {
if (!methodReference.getClassName().equals(Long.class.getName())) {
return false;
}
switch (methodReference.getName()) {
case "divideUnsigned":
case "remainderUnsigned":
return true;
default:
return false;
}
}
@Override
public WasmExpression apply(InvocationExpr invocation, WasmIntrinsicManager manager) {
switch (invocation.getMethod().getName()) {
case "divideUnsigned":
return new WasmIntBinary(WasmIntType.INT64, WasmIntBinaryOperation.DIV_UNSIGNED,
manager.generate(invocation.getArguments().get(0)),
manager.generate(invocation.getArguments().get(1)));
case "remainderUnsigned":
return new WasmIntBinary(WasmIntType.INT64, WasmIntBinaryOperation.REM_UNSIGNED,
manager.generate(invocation.getArguments().get(0)),
manager.generate(invocation.getArguments().get(1)));
default:
throw new AssertionError();
}
}
}

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@ -274,3 +274,24 @@ static int32_t teavm_timeZoneOffset() {
static char* teavm_stringToC(void*);
static inline void teavm_free(void*);
static inline int64_t teavm_reinterpretDoubleToLong(double v) {
union { int64_t longValue; double doubleValue; } conv;
conv.doubleValue = v;
return conv.longValue;
}
static inline double teavm_reinterpretLongToDouble(int64_t v) {
union { int64_t longValue; double doubleValue; } conv;
conv.longValue = v;
return conv.doubleValue;
}
static inline int32_t teavm_reinterpretFloatToInt(float v) {
union { int32_t intValue; float floatValue; } conv;
conv.floatValue = v;
return conv.intValue;
}
static inline float teavm_reinterpretIntToFloat(int32_t v) {
union { int32_t intValue; float floatValue; } conv;
conv.intValue = v;
return conv.floatValue;
}

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@ -197,12 +197,24 @@ function Long_div(a, b) {
}
return Long_divRem(a, b)[0];
}
function Long_udiv(a, b) {
if (a.hi >= 0 && a.hi < Long_MAX_NORMAL && b.hi >= 0 && b.hi < Long_MAX_NORMAL) {
return Long_fromNumber(Long_toNumber(a) / Long_toNumber(b));
}
return Long_udivRem(a, b)[0];
}
function Long_rem(a, b) {
if (Math.abs(a.hi) < Long_MAX_NORMAL && Math.abs(b.hi) < Long_MAX_NORMAL) {
return Long_fromNumber(Long_toNumber(a) % Long_toNumber(b));
}
return Long_divRem(a, b)[1];
}
function Long_urem(a, b) {
if (a.hi >= 0 && a.hi < Long_MAX_NORMAL && b.hi >= 0 && b.hi < Long_MAX_NORMAL) {
return Long_fromNumber(Long_toNumber(a) / Long_toNumber(b));
}
return Long_udivRem(a, b)[1];
}
function Long_divRem(a, b) {
if (b.lo === 0 && b.hi === 0) {
throw new Error("Division by zero");
@ -221,6 +233,17 @@ function Long_divRem(a, b) {
q = new Long(q.lo, q.hi);
return positive ? [q, a] : [Long_neg(q), Long_neg(a)];
}
function Long_udivRem(a, b) {
if (b.lo === 0 && b.hi === 0) {
throw new Error("Division by zero");
}
a = new LongInt(a.lo, a.hi, 0);
b = new LongInt(b.lo, b.hi, 0);
var q = LongInt_div(a, b);
a = new Long(a.lo, a.hi);
q = new Long(q.lo, q.hi);
return [q, a];
}
function Long_shiftLeft16(a) {
return new Long(a.lo << 16, (a.lo >>> 16) | (a.hi << 16));
}

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@ -279,8 +279,8 @@ public class StringBuilderTest {
@Test
public void minDoubleAppended() {
StringBuilder sb = new StringBuilder();
sb.append(2.2250738585072E-308);
assertEquals("2.2250738585072E-308", sb.toString());
sb.append(3E-308);
assertEquals("3.0E-308", sb.toString());
}
@Test