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10k improvement (#419)

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* Remove commented-out params from the script

* General cleanup and refactoring

* Deoptimize parseTemperatureSimple

* Optimize nameEquals()
This commit is contained in:
Marko Topolnik
2024-01-15 18:49:32 +01:00
committed by GitHub
parent 6c7012a43e
commit ecab306338
2 changed files with 111 additions and 84 deletions
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193
src/main/java/dev/morling/onebrc/CalculateAverage_mtopolnik.java
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@@ -155,39 +155,52 @@ public class CalculateAverage_mtopolnik {
}
}
private static final int MAX_TEMPERATURE_LEN = 5;
private static final int MAX_ROW_LEN = MAX_NAME_LEN + 1 + MAX_TEMPERATURE_LEN + 1;
private static final long DANGER_ZONE_LENGTH = ((MAX_ROW_LEN - 1) / 8 * 8 + 8);
private void processChunk() {
while (cursor < inputSize) {
boolean withinSafeZone;
long word1;
long word2;
if (cursor + 2 * Long.BYTES <= inputSize) {
word1 = UNSAFE.getLong(inputBase + cursor);
word2 = UNSAFE.getLong(inputBase + cursor + Long.BYTES);
long nameLen;
long nameStartAddress = inputBase + cursor;
if (cursor + DANGER_ZONE_LENGTH <= inputSize) {
withinSafeZone = true;
word1 = UNSAFE.getLong(nameStartAddress);
word2 = UNSAFE.getLong(nameStartAddress + Long.BYTES);
nameLen = nameLen(word1, word2, withinSafeZone);
word1 = maskWord(word1, nameLen);
word2 = maskWord(word2, nameLen - Long.BYTES);
}
else {
withinSafeZone = false;
UNSAFE.putLong(nameBufBase, 0);
UNSAFE.putLong(nameBufBase + Long.BYTES, 0);
UNSAFE.copyMemory(inputBase + cursor, nameBufBase, Long.min(NAMEBUF_SIZE, inputSize - cursor));
UNSAFE.copyMemory(nameStartAddress, nameBufBase, Long.min(NAMEBUF_SIZE, inputSize - cursor));
word1 = UNSAFE.getLong(nameBufBase);
word2 = UNSAFE.getLong(nameBufBase + Long.BYTES);
nameLen = nameLen(word1, word2, withinSafeZone);
}
long posOfSemicolon = posOfSemicolon(word1, word2);
word1 = maskWord(word1, posOfSemicolon - cursor);
word2 = maskWord(word2, posOfSemicolon - cursor - Long.BYTES);
long hash = hash(word1);
long namePos = cursor;
long nameLen = posOfSemicolon - cursor;
assert nameLen <= 100 : "nameLen > 100";
int temperature = parseTemperatureAndAdvanceCursor(posOfSemicolon);
updateStats(hash, namePos, nameLen, word1, word2, temperature);
assert nameLen > 0 && nameLen <= 100 : nameLen;
long tempStartAddress = nameStartAddress + nameLen + 1;
int temperature = withinSafeZone
? parseTemperatureSwarAndAdvanceCursor(tempStartAddress)
: parseTemperatureSimpleAndAdvanceCursor(tempStartAddress);
updateStats(hash, nameStartAddress, nameLen, word1, word2, temperature, withinSafeZone);
}
}
private void updateStats(long hash, long namePos, long nameLen, long nameWord1, long nameWord2, int temperature) {
private void updateStats(
long hash, long nameStartAddress, long nameLen, long nameWord1, long nameWord2,
int temperature, boolean withinSafeZone) {
int tableIndex = (int) (hash & TABLE_INDEX_MASK);
while (true) {
stats.gotoIndex(tableIndex);
if (stats.hash() == hash && stats.nameLen() == nameLen
&& nameEquals(stats.nameAddress(), inputBase + namePos, nameLen, nameWord1, nameWord2)) {
if (stats.hash() == hash && stats.nameLen() == nameLen && nameEquals(
stats.nameAddress(), nameStartAddress, nameLen, nameWord1, nameWord2, withinSafeZone)) {
stats.setSum(stats.sum() + temperature);
stats.setCount(stats.count() + 1);
stats.setMin((short) Integer.min(stats.min(), temperature));
@@ -204,72 +217,58 @@ public class CalculateAverage_mtopolnik {
stats.setCount(1);
stats.setMin((short) temperature);
stats.setMax((short) temperature);
UNSAFE.copyMemory(inputBase + namePos, stats.nameAddress(), nameLen);
UNSAFE.copyMemory(nameStartAddress, stats.nameAddress(), nameLen);
return;
}
}
private int parseTemperatureAndAdvanceCursor(long semicolonPos) {
long startOffset = semicolonPos + 1;
if (startOffset <= inputSize - Long.BYTES) {
return parseTemperatureSwarAndAdvanceCursor(startOffset);
}
return parseTemperatureSimpleAndAdvanceCursor(startOffset);
}
// Credit: merykitty
private int parseTemperatureSwarAndAdvanceCursor(long startOffset) {
long word = UNSAFE.getLong(inputBase + startOffset);
private int parseTemperatureSwarAndAdvanceCursor(long tempStartAddress) {
long word = UNSAFE.getLong(tempStartAddress);
final long negated = ~word;
final int dotPos = Long.numberOfTrailingZeros(negated & 0x10101000);
cursor = (tempStartAddress + (dotPos / 8) + 3) - inputBase;
final long signed = (negated << 59) >> 63;
final long removeSignMask = ~(signed & 0xFF);
final long digits = ((word & removeSignMask) << (28 - dotPos)) & 0x0F000F0F00L;
final long absValue = ((digits * 0x640a0001) >>> 32) & 0x3FF;
final int temperature = (int) ((absValue ^ signed) - signed);
cursor = startOffset + (dotPos / 8) + 3;
return temperature;
return (int) ((absValue ^ signed) - signed);
}
private int parseTemperatureSimpleAndAdvanceCursor(long startOffset) {
private int parseTemperatureSimpleAndAdvanceCursor(long tempStartAddress) {
final byte minus = (byte) '-';
final byte zero = (byte) '0';
final byte dot = (byte) '.';
// Temperature plus the following newline is at least 4 chars, so this is always safe:
int fourCh = UNSAFE.getInt(inputBase + startOffset);
final int mask = 0xFF;
byte ch = (byte) (fourCh & mask);
int shift = 0;
byte ch = UNSAFE.getByte(tempStartAddress);
long address = tempStartAddress;
int temperature;
int sign;
if (ch == minus) {
sign = -1;
shift += 8;
ch = (byte) ((fourCh & (mask << shift)) >>> shift);
address++;
ch = UNSAFE.getByte(address);
}
else {
sign = 1;
}
temperature = ch - zero;
shift += 8;
ch = (byte) ((fourCh & (mask << shift)) >>> shift);
address++;
ch = UNSAFE.getByte(address);
if (ch == dot) {
shift += 8;
ch = (byte) ((fourCh & (mask << shift)) >>> shift);
address++;
ch = UNSAFE.getByte(address);
}
else {
temperature = 10 * temperature + (ch - zero);
shift += 16;
// The last character may be past the four loaded bytes, load it from memory.
// Checking that with another `if` is self-defeating for performance.
ch = UNSAFE.getByte(inputBase + startOffset + (shift / 8));
address += 2;
ch = UNSAFE.getByte(address);
}
temperature = 10 * temperature + (ch - zero);
// `shift` holds the number of bits in the temperature field.
// address - inputBase is the length of the temperature field.
// A newline character follows the temperature, and so we advance
// the cursor past the newline to the start of the next line.
cursor = startOffset + (shift / 8) + 2;
cursor = (address + 2) - inputBase;
return sign * temperature;
}
@@ -286,15 +285,27 @@ public class CalculateAverage_mtopolnik {
return hash;
}
private static boolean nameEquals(long statsAddr, long inputAddr, long len, long inputWord1, long inputWord2) {
private static boolean nameEquals(long statsAddr, long inputAddr, long len, long inputWord1, long inputWord2,
boolean withinSafeZone) {
boolean mismatch1 = maskWord(inputWord1, len) != UNSAFE.getLong(statsAddr);
boolean mismatch2 = maskWord(inputWord2, len - Long.BYTES) != UNSAFE.getLong(statsAddr + Long.BYTES);
if (mismatch1 | mismatch2) {
return false;
if (len <= 2 * Long.BYTES) {
return !(mismatch1 | mismatch2);
}
for (int i = 2 * Long.BYTES; i < len; i++) {
if (UNSAFE.getByte(inputAddr + i) != UNSAFE.getByte(statsAddr + i)) {
return false;
if (withinSafeZone) {
int i = 2 * Long.BYTES;
for (; i <= len - Long.BYTES; i += Long.BYTES) {
if (UNSAFE.getLong(inputAddr + i) != UNSAFE.getLong(statsAddr + i)) {
return false;
}
}
return maskWord(UNSAFE.getLong(inputAddr + i), len - i) == UNSAFE.getLong(statsAddr + i);
}
else {
for (int i = 2 * Long.BYTES; i < len; i++) {
if (UNSAFE.getByte(inputAddr + i) != UNSAFE.getByte(statsAddr + i)) {
return false;
}
}
}
return true;
@@ -311,44 +322,62 @@ public class CalculateAverage_mtopolnik {
// Adapted from https://jameshfisher.com/2017/01/24/bitwise-check-for-zero-byte/
// and https://github.com/ashvardanian/StringZilla/blob/14e7a78edcc16b031c06b375aac1f66d8f19d45a/stringzilla/stringzilla.h#L139-L169
long posOfSemicolon(long word1, long word2) {
long diff = word1 ^ BROADCAST_SEMICOLON;
long matchBits1 = (diff - BROADCAST_0x01) & ~diff & BROADCAST_0x80;
diff = word2 ^ BROADCAST_SEMICOLON;
long matchBits2 = (diff - BROADCAST_0x01) & ~diff & BROADCAST_0x80;
if ((matchBits1 | matchBits2) != 0) {
int trailing1 = Long.numberOfTrailingZeros(matchBits1);
int match1IsNonZero = trailing1 & 63;
match1IsNonZero |= match1IsNonZero >>> 3;
match1IsNonZero |= match1IsNonZero >>> 1;
match1IsNonZero |= match1IsNonZero >>> 1;
// Now match1IsNonZero is 1 if it's non-zero, else 0. Use it to
// raise the lowest bit in traling2 if trailing1 is nonzero. This forces
// trailing2 to be zero if trailing1 is non-zero.
int trailing2 = Long.numberOfTrailingZeros(matchBits2 | match1IsNonZero) & 63;
return cursor + ((trailing1 | trailing2) >> 3);
}
long offset = cursor + 2 * Long.BYTES;
for (; offset <= inputSize - Long.BYTES; offset += Long.BYTES) {
var block = UNSAFE.getLong(inputBase + offset);
diff = block ^ BROADCAST_SEMICOLON;
long matchBits = (diff - BROADCAST_0x01) & ~diff & BROADCAST_0x80;
if (matchBits != 0) {
return offset + Long.numberOfTrailingZeros(matchBits) / 8;
long nameLen(long word1, long word2, boolean withinSafeZone) {
{
long matchBits1 = matchBits(word1);
long matchBits2 = matchBits(word2);
if ((matchBits1 | matchBits2) != 0) {
int trailing1 = Long.numberOfTrailingZeros(matchBits1);
int match1IsNonZero = trailing1 & 63;
match1IsNonZero |= match1IsNonZero >>> 3;
match1IsNonZero |= match1IsNonZero >>> 1;
match1IsNonZero |= match1IsNonZero >>> 1;
// Now match1IsNonZero is 1 if it's non-zero, else 0. Use it to
// raise the lowest bit in trailing2 if trailing1 is nonzero. This forces
// trailing2 to be zero if trailing1 is non-zero.
int trailing2 = Long.numberOfTrailingZeros(matchBits2 | match1IsNonZero) & 63;
// trailing1 | trailing2 works like trailing1 + trailing2 because if trailing2 is non-zero,
// then trailing1 is 64, and since trailing2 is < 64, there's no bit overlap.
return (trailing1 | trailing2) >> 3;
}
}
return posOfSemicolonSimple(offset);
long nameStartAddress = inputBase + cursor;
long address = nameStartAddress + 2 * Long.BYTES;
long limit = inputBase + inputSize;
if (withinSafeZone) {
for (; address < limit; address += Long.BYTES) {
var block = maskWord(UNSAFE.getLong(address), limit - address);
long matchBits = matchBits(block);
if (matchBits != 0) {
return address + (Long.numberOfTrailingZeros(matchBits) >> 3) - nameStartAddress;
}
}
throw new RuntimeException("Semicolon not found");
}
return addrOfSemicolonSafe(address, limit) - nameStartAddress;
}
private long posOfSemicolonSimple(long offset) {
for (; offset < inputSize; offset++) {
if (UNSAFE.getByte(inputBase + offset) == SEMICOLON) {
return offset;
private static long addrOfSemicolonSafe(long address, long limit) {
for (; address < limit - Long.BYTES + 1; address += Long.BYTES) {
var block = UNSAFE.getLong(address);
long matchBits = matchBits(block);
if (matchBits != 0) {
return address + (Long.numberOfTrailingZeros(matchBits) >> 3);
}
}
for (; address < limit; address++) {
if (UNSAFE.getByte(address) == SEMICOLON) {
return address;
}
}
throw new RuntimeException("Semicolon not found");
}
private static long matchBits(long word) {
long diff = word ^ BROADCAST_SEMICOLON;
return (diff - BROADCAST_0x01) & ~diff & BROADCAST_0x80;
}
// Copies the results from native memory to Java heap and puts them into the results array.
private void exportResults() {
var exportedStats = new ArrayList<StationStats>(10_000);