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Process two consecutive lines at a time (#651)

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Use a better hash function

Don't return index from temperature parsing
extra JVM args

Co-authored-by: Ian Preston <ianopolous@protonmail.com>
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Dr Ian Preston 2024-01-31 16:06:05 +00:00 committed by GitHub
parent ab2a9a6fe5
commit 0c5c22882b
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GPG Key ID: B5690EEEBB952194
2 changed files with 66 additions and 88 deletions
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2
calculate_average_ianopolousfast.sh
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@ -16,4 +16,6 @@
# #
JAVA_OPTS="--enable-preview --add-modules=jdk.incubator.vector" JAVA_OPTS="--enable-preview --add-modules=jdk.incubator.vector"
#-Djdk.incubator.vector.VECTOR_ACCESS_OOB_CHECK=0 -XX:-UseTransparentHugePages"
java $JAVA_OPTS --class-path target/average-1.0.0-SNAPSHOT.jar dev.morling.onebrc.CalculateAverage_ianopolousfast java $JAVA_OPTS --class-path target/average-1.0.0-SNAPSHOT.jar dev.morling.onebrc.CalculateAverage_ianopolousfast

152
src/main/java/dev/morling/onebrc/CalculateAverage_ianopolousfast.java
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@ -19,7 +19,6 @@ import jdk.incubator.vector.ByteVector;
import jdk.incubator.vector.VectorOperators; import jdk.incubator.vector.VectorOperators;
import jdk.incubator.vector.VectorSpecies; import jdk.incubator.vector.VectorSpecies;
import java.io.IOException;
import java.lang.foreign.Arena; import java.lang.foreign.Arena;
import java.lang.foreign.MemorySegment; import java.lang.foreign.MemorySegment;
import java.nio.ByteOrder; import java.nio.ByteOrder;
@ -39,10 +38,7 @@ import static java.lang.foreign.ValueLayout.*;
* * read chunks in parallel * * read chunks in parallel
* * minimise allocation * * minimise allocation
* * no unsafe * * no unsafe
* * * process multiple lines in each thread for better ILP
* Timings on 4 core i7-7500U CPU @ 2.70GHz:
* average_baseline: 4m48s
* ianopolous: 13.8s
*/ */
public class CalculateAverage_ianopolousfast { public class CalculateAverage_ianopolousfast {
@ -91,11 +87,22 @@ public class CalculateAverage_ianopolousfast {
return true; return true;
} }
private static int hashToIndex(long hash, int len) { private static final int GOLDEN_RATIO = 0x9E3779B9;
// From Thomas Wuerthinger's entry private static final int HASH_LROTATE = 5;
int hashAsInt = (int) (hash ^ (hash >>> 28));
int finalHash = (hashAsInt ^ (hashAsInt >>> 15)); // hash from giovannicuccu
return (finalHash & (len - 1)); private static int hash(MemorySegment memorySegment, long start, int len) {
int x;
int y;
if (len >= Integer.BYTES) {
x = memorySegment.get(JAVA_INT_UNALIGNED, start);
y = memorySegment.get(JAVA_INT_UNALIGNED, start + len - Integer.BYTES);
}
else {
x = memorySegment.get(JAVA_BYTE, start);
y = memorySegment.get(JAVA_BYTE, start + len - Byte.BYTES);
}
return (Integer.rotateLeft(x * GOLDEN_RATIO, HASH_LROTATE) ^ y) * GOLDEN_RATIO;
} }
public static Stat createStation(long start, long end, MemorySegment buffer) { public static Stat createStation(long start, long end, MemorySegment buffer) {
@ -105,8 +112,9 @@ public class CalculateAverage_ianopolousfast {
return new Stat(stationBuffer); return new Stat(stationBuffer);
} }
public static Stat dedupeStation(long start, long end, long hash, MemorySegment buffer, Stat[] stations) { public static Stat dedupeStation(long start, long end, MemorySegment buffer, Stat[] stations) {
int index = hashToIndex(hash, MAX_STATIONS); int hash = hash(buffer, start, (int) (end - start));
int index = hash & (MAX_STATIONS - 1);
Stat match = stations[index]; Stat match = stations[index];
while (match != null) { while (match != null) {
if (matchingStationBytes(start, end, buffer, match)) if (matchingStationBytes(start, end, buffer, match))
@ -119,37 +127,11 @@ public class CalculateAverage_ianopolousfast {
return res; return res;
} }
static long maskHighBytes(long d, int nbytes) {
return d & (-1L << ((8 - nbytes) * 8));
}
public static Stat parseStation(long lineStart, MemorySegment buffer, Stat[] stations) {
ByteVector line = ByteVector.fromMemorySegment(BYTE_SPECIES, buffer, lineStart, ByteOrder.nativeOrder());
int keySize = line.compare(VectorOperators.EQ, ';').firstTrue();
long first8 = buffer.get(LONG_LAYOUT, lineStart);
long second8 = 0;
if (keySize <= 8) {
first8 = maskHighBytes(first8, keySize & 0x07);
}
else if (keySize < 16) {
second8 = maskHighBytes(buffer.get(LONG_LAYOUT, lineStart + 8), keySize & 0x07);
}
else if (keySize == BYTE_SPECIES.vectorByteSize()) {
while (buffer.get(JAVA_BYTE, lineStart + keySize) != ';') {
keySize++;
}
second8 = maskHighBytes(buffer.get(LONG_LAYOUT, lineStart + 8), keySize & 0x07);
}
long hash = first8 ^ second8; // todo include later bytes
return dedupeStation(lineStart, lineStart + keySize, hash, buffer, stations);
}
public static short getMinus(long d) { public static short getMinus(long d) {
return ((d & 0xff00000000000000L) ^ 0x2d00000000000000L) != 0 ? 0 : (short) -1; return ((d & 0xff00000000000000L) ^ 0x2d00000000000000L) != 0 ? 0 : (short) -1;
} }
public static long processTemperature(long lineSplit, int size, MemorySegment buffer, Stat station) { public static void processTemperature(long lineSplit, int size, MemorySegment buffer, Stat station) {
long d = buffer.get(LONG_LAYOUT, lineSplit); long d = buffer.get(LONG_LAYOUT, lineSplit);
// negative is either 0 or -1 // negative is either 0 or -1
short negative = getMinus(d); short negative = getMinus(d);
@ -162,10 +144,9 @@ public class CalculateAverage_ianopolousfast {
100 * (((byte) (d >> 24)) - '0')); 100 * (((byte) (d >> 24)) - '0'));
temperature = (short) ((temperature ^ negative) - negative); // negative treatment inspired by merkitty temperature = (short) ((temperature ^ negative) - negative); // negative treatment inspired by merkitty
station.add(temperature); station.add(temperature);
return lineSplit + size + 1;
} }
private static long parseLine(long lineStart, MemorySegment buffer, Stat[] stations) { private static int lineSize(long lineStart, MemorySegment buffer) {
ByteVector line = ByteVector.fromMemorySegment(BYTE_SPECIES, buffer, lineStart, ByteOrder.nativeOrder()); ByteVector line = ByteVector.fromMemorySegment(BYTE_SPECIES, buffer, lineStart, ByteOrder.nativeOrder());
int lineSize = line.compare(VectorOperators.EQ, '\n').firstTrue(); int lineSize = line.compare(VectorOperators.EQ, '\n').firstTrue();
int index = lineSize; int index = lineSize;
@ -174,33 +155,19 @@ public class CalculateAverage_ianopolousfast {
ByteOrder.nativeOrder()).compare(VectorOperators.EQ, '\n').firstTrue(); ByteOrder.nativeOrder()).compare(VectorOperators.EQ, '\n').firstTrue();
lineSize += index; lineSize += index;
} }
int keySize = lineSize - 6 + ByteVector.fromMemorySegment(BYTE_SPECIES, buffer, lineStart + lineSize - 6, return lineSize;
ByteOrder.nativeOrder()).compare(VectorOperators.EQ, ';').firstTrue();
long first8 = buffer.get(LONG_LAYOUT, lineStart);
long second8 = 0;
if (keySize <= 8) {
first8 = maskHighBytes(first8, keySize & 0x07);
}
else if (keySize < 16) {
second8 = maskHighBytes(buffer.get(LONG_LAYOUT, lineStart + 8), keySize & 0x07);
}
else if (keySize == BYTE_SPECIES.vectorByteSize()) {
while (buffer.get(JAVA_BYTE, lineStart + keySize) != ';') {
keySize++;
}
second8 = maskHighBytes(buffer.get(LONG_LAYOUT, lineStart + 8), keySize & 0x07);
}
long hash = first8 ^ second8; // todo include later bytes
Stat station = dedupeStation(lineStart, lineStart + keySize, hash, buffer, stations);
return processTemperature(lineStart + keySize + 1, lineSize - keySize - 1, buffer, station);
} }
public static Stat[] parseStats(long startByte, long endByte, MemorySegment buffer) { private static int keySize(int lineSize, long lineStart, MemorySegment buffer) {
return lineSize - 6 + ByteVector.fromMemorySegment(BYTE_SPECIES, buffer, lineStart + lineSize - 6,
ByteOrder.nativeOrder()).compare(VectorOperators.EQ, ';').firstTrue();
}
public static Stat[] parseStats(long start1, long end2, MemorySegment buffer) {
// read first partial line // read first partial line
if (startByte > 0) { if (start1 > 0) {
for (int i = 0; i < MAX_LINE_LENGTH; i++) { for (int i = 0; i < MAX_LINE_LENGTH; i++) {
byte b = buffer.get(JAVA_BYTE, startByte++); byte b = buffer.get(JAVA_BYTE, start1++);
if (b == '\n') { if (b == '\n') {
break; break;
} }
@ -213,38 +180,47 @@ public class CalculateAverage_ianopolousfast {
// this allows us to not worry about reading beyond the end // this allows us to not worry about reading beyond the end
// in the inner loop (reducing branches) // in the inner loop (reducing branches)
// We need at least the vector lane size bytes back // We need at least the vector lane size bytes back
if (endByte == buffer.byteSize()) { if (end2 == buffer.byteSize()) {
// reverse at least vector lane width // reverse at least vector lane width
endByte = Math.max(buffer.byteSize() - BYTE_SPECIES.vectorByteSize(), 0); end2 = Math.max(buffer.byteSize() - 2 * BYTE_SPECIES.vectorByteSize(), 0);
while (endByte > 0 && buffer.get(JAVA_BYTE, endByte) != '\n') while (end2 > 0 && buffer.get(JAVA_BYTE, end2) != '\n')
endByte--; end2--;
if (endByte > 0) if (end2 > 0)
endByte++; end2++;
// copy into a larger buffer to avoid reading off end // copy into a larger buffer to avoid reading off end
MemorySegment end = Arena.global().allocate(MAX_LINE_LENGTH + BYTE_SPECIES.vectorByteSize()); MemorySegment end = Arena.global().allocate(MAX_LINE_LENGTH + 2 * BYTE_SPECIES.vectorByteSize());
for (long i = endByte; i < buffer.byteSize(); i++) for (long i = end2; i < buffer.byteSize(); i++)
end.set(JAVA_BYTE, i - endByte, buffer.get(JAVA_BYTE, i)); end.set(JAVA_BYTE, i - end2, buffer.get(JAVA_BYTE, i));
int index = 0; int index = 0;
while (endByte + index < buffer.byteSize()) { while (end2 + index < buffer.byteSize()) {
Stat station = parseStation(index, end, stations); int lineSize1 = lineSize(index, end);
int tempSize = 3; int semiSearchStart = index + Math.max(0, lineSize1 - 6);
if (end.get(JAVA_BYTE, index + station.namelen + 5) == '\n') int keySize1 = semiSearchStart - index + ByteVector.fromMemorySegment(BYTE_SPECIES, end, semiSearchStart,
tempSize = 4; ByteOrder.nativeOrder()).compare(VectorOperators.EQ, ';').firstTrue();
if (end.get(JAVA_BYTE, index + station.namelen + 6) == '\n') Stat station1 = dedupeStation(index, index + keySize1, end, stations);
tempSize = 5; processTemperature(index + keySize1 + 1, lineSize1 - keySize1 - 1, end, station1);
index = (int) processTemperature(index + station.namelen + 1, tempSize, end, station); index += lineSize1 + 1;
} }
} }
innerloop(startByte, endByte, buffer, stations); while (start1 < end2) {
return stations; int lineSize1 = lineSize(start1, buffer);
} long start2 = start1 + lineSize1 + 1;
int lineSize2 = start2 < end2 ? lineSize(start2, buffer) : 0;
private static void innerloop(long startByte, long endByte, MemorySegment buffer, Stat[] stations) { int keySize1 = keySize(lineSize1, start1, buffer);
while (startByte < endByte) { int keySize2 = keySize(lineSize2, start2, buffer);
startByte = parseLine(startByte, buffer, stations); Stat station1 = dedupeStation(start1, start1 + keySize1, buffer, stations);
processTemperature(start1 + keySize1 + 1, lineSize1 - keySize1 - 1, buffer, station1);
if (start2 < end2) {
Stat station2 = dedupeStation(start2, start2 + keySize2, buffer, stations);
processTemperature(start2 + keySize2 + 1, lineSize2 - keySize2 - 1, buffer, station2);
start1 = start2 + lineSize2 + 1;
}
else
start1 += lineSize1 + 1;
} }
return stations;
} }
public static class Stat { public static class Stat {