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Merged
fglock merged 3 commits into from
Oct 28, 2026
Merged

perf: close remaining regex performance gap vs native Perl #1908

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3b00c2c
perf: round 4 regex hot-path — reduce ThreadLocal reads, fast INTEGER…
fglock Oct 27, 2026
a47a6ea
perf: round 5 regex hot-path — literal fast path, merged ThreadLocal
fglock Oct 27, 2026
553f600
fix: literal regex fast path must not taint match results
fglock Oct 28, 2026
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10 changes: 4 additions & 6 deletions src/main/java/org/perlonjava/backend/bytecode/BytecodeInterpreter.java
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Original file line number Diff line number Diff line change
Expand Up @@ -4387,9 +4387,8 @@ private static int executeTypeOps(int opcode, int[] bytecode, int pc,
if (implicitU != 0) {
flags = RuntimeRegex.applyUnicodeStringsFeatureToModifiers(flags);
}
RegexQuoteMeta.setCallSiteWarningState(warningState);
RegexQuoteMeta.setCallSiteWarningBits(warningBitsIndex >= 0
? code.stringPool[warningBitsIndex] : null);
RegexQuoteMeta.setCallSiteWarning(warningState,
warningBitsIndex >= 0 ? code.stringPool[warningBitsIndex] : null);
registers[rd] = RuntimeRegex.getQuotedRegex(
registers[patternReg].scalar(), flags,
namedCharacterExpansions);
Expand Down Expand Up @@ -4419,9 +4418,8 @@ private static int executeTypeOps(int opcode, int[] bytecode, int pc,
if (implicitU != 0) {
flags = RuntimeRegex.applyUnicodeStringsFeatureToModifiers(flags);
}
RegexQuoteMeta.setCallSiteWarningState(warningState);
RegexQuoteMeta.setCallSiteWarningBits(warningBitsIndex >= 0
? code.stringPool[warningBitsIndex] : null);
RegexQuoteMeta.setCallSiteWarning(warningState,
warningBitsIndex >= 0 ? code.stringPool[warningBitsIndex] : null);
registers[rd] = RuntimeRegex.getQuotedRegex(
registers[patternReg].scalar(), flags, callsiteId,
namedCharacterExpansions);
Expand Down
5 changes: 1 addition & 4 deletions src/main/java/org/perlonjava/backend/jvm/EmitRegex.java
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Expand Up @@ -76,9 +76,6 @@ private static void emitRegexWarningState(EmitterVisitor emitterVisitor, Operato
emitterVisitor.ctx.mv.visitInsn(suppressed ? Opcodes.ICONST_M1
: fatal ? Opcodes.ICONST_2
: enabled ? Opcodes.ICONST_1 : Opcodes.ICONST_0);
emitterVisitor.ctx.mv.visitMethodInsn(Opcodes.INVOKESTATIC,
"org/perlonjava/runtime/regex/RegexQuoteMeta",
"setCallSiteWarningState", "(I)V", false);
Object warningBits = node.getAnnotation("regexWarningBits");
if (warningBits instanceof String bits) {
emitterVisitor.ctx.mv.visitLdcInsn(bits);
Expand All @@ -87,7 +84,7 @@ private static void emitRegexWarningState(EmitterVisitor emitterVisitor, Operato
}
emitterVisitor.ctx.mv.visitMethodInsn(Opcodes.INVOKESTATIC,
"org/perlonjava/runtime/regex/RegexQuoteMeta",
"setCallSiteWarningBits", "(Ljava/lang/String;)V", false);
"setCallSiteWarning", "(ILjava/lang/String;)V", false);
}

/** Stack: pattern -> pattern carrying this literal's immutable lexical results. */
Expand Down
90 changes: 83 additions & 7 deletions src/main/java/org/perlonjava/runtime/regex/JoniRegexPattern.java
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Expand Up @@ -74,6 +74,28 @@ record DeferredPropertyFact(String name, String displayName,
private static final int INPUT_ENCODING_CACHE_ENTRIES = 512;
private static final int INPUT_ENCODING_CACHE_MAX_LENGTH = 8_192;
private static final int DYNAMIC_PATTERN_CACHE_ENTRIES = 128;

private static final int IDENTITY_ARRAY_POOL_SIZE = 64;
private static final int[][] IDENTITY_ARRAYS = buildIdentityArrayPool();

private static int[][] buildIdentityArrayPool() {
int[][] pool = new int[IDENTITY_ARRAY_POOL_SIZE + 1][];
for (int len = 0; len <= IDENTITY_ARRAY_POOL_SIZE; len++) {
int[] identity = new int[len + 1];
for (int i = 0; i <= len; i++) identity[i] = i;
pool[len] = identity;
}
return pool;
}

private static int[] identityArray(int length) {
if (length <= IDENTITY_ARRAY_POOL_SIZE) {
return IDENTITY_ARRAYS[length];
}
int[] identity = new int[length + 1];
for (int i = 0; i <= length; i++) identity[i] = i;
return identity;
}
private static final Map<String, InputEncoding> INPUT_ENCODINGS = inputEncodingCache();
private static final Map<String, InputEncoding> BYTE_INPUT_ENCODINGS = inputEncodingCache();
private static final Map<RuntimeScalar, SubjectInputEncodings> SUBJECT_INPUT_ENCODINGS =
Expand Down Expand Up @@ -324,6 +346,7 @@ private static CharacterPropertyResolver.Result resolveCharacterProperty(
private final boolean byteMode;
private final java.nio.charset.Charset sourceCharset;
private final List<String> compileWarnings;
private final String fixedLiteral;

JoniRegexPattern(String perlPattern, RegexFlags flags) {
this(perlPattern, flags, 0, false);
Expand Down Expand Up @@ -455,6 +478,27 @@ public boolean supportsPositions() {
NamedGroupMaps groupMaps = collectNamedGroups(regex);
namedGroups = groupMaps.logical();
physicalNamedGroups = groupMaps.physical();
fixedLiteral = detectFixedLiteral(sourcePattern, regex, flags, byteMode);
}

private static String detectFixedLiteral(String pattern, Regex compiled,
RegexFlags flags, boolean byteMode) {
if (compiled.numberOfCaptures() != 0 || byteMode) return null;
if (flags != null && (flags.isCaseInsensitive() || flags.isExtended())) return null;
for (int i = 0; i < pattern.length(); i++) {
char c = pattern.charAt(i);
if (c == '\\' || c == '.' || c == '^' || c == '$' || c == '*'
|| c == '+' || c == '?' || c == '{' || c == '}'
|| c == '[' || c == ']' || c == '(' || c == ')'
|| c == '|') {
return null;
}
}
return pattern.isEmpty() ? null : pattern;
}

String getFixedLiteral() {
return fixedLiteral;
}

private record WarningDisplay(String pattern, int offset) {}
Expand Down Expand Up @@ -655,7 +699,13 @@ static InputEncoding inputEncoding(String input, RuntimeScalar subject, boolean
}

static InputEncoding inputEncoding(String input) {
if (input.length() > INPUT_ENCODING_CACHE_MAX_LENGTH) {
int len = input.length();
if (len <= IDENTITY_ARRAY_POOL_SIZE && isAscii(input, len)) {
byte[] bytes = asciiToBytes(input, len);
int[] identity = IDENTITY_ARRAYS[len];
return new InputEncoding(bytes, identity, identity);
}
if (len > INPUT_ENCODING_CACHE_MAX_LENGTH) {
return buildInputEncoding(input);
}
synchronized (INPUT_ENCODINGS) {
Expand All @@ -664,7 +714,14 @@ static InputEncoding inputEncoding(String input) {
}

static InputEncoding byteInputEncoding(String input) {
if (input.length() > INPUT_ENCODING_CACHE_MAX_LENGTH) {
int len = input.length();
if (len <= IDENTITY_ARRAY_POOL_SIZE) {
byte[] bytes = new byte[len];
for (int i = 0; i < len; i++) bytes[i] = (byte) input.charAt(i);
int[] identity = IDENTITY_ARRAYS[len];
return new InputEncoding(bytes, identity, identity);
}
if (len > INPUT_ENCODING_CACHE_MAX_LENGTH) {
return buildByteInputEncoding(input);
}
synchronized (BYTE_INPUT_ENCODINGS) {
Expand All @@ -675,23 +732,42 @@ static InputEncoding byteInputEncoding(String input) {

private static InputEncoding buildByteInputEncoding(String input) {
byte[] bytes = input.getBytes(StandardCharsets.ISO_8859_1);
int[] identity = new int[input.length() + 1];
for (int i = 0; i < identity.length; i++) identity[i] = i;
int[] identity = identityArray(input.length());
return new InputEncoding(bytes, identity, identity);
}

private static InputEncoding buildInputEncoding(String input) {
int len = input.length();
if (isAscii(input, len)) {
byte[] bytes = asciiToBytes(input, len);
int[] identity = identityArray(len);
return new InputEncoding(bytes, identity, identity);
}
byte[] bytes = input.getBytes(StandardCharsets.UTF_8);
if (bytes.length == input.length()) {
int[] identity = new int[input.length() + 1];
for (int i = 0; i <= input.length(); i++) identity[i] = i;
if (bytes.length == len) {
int[] identity = identityArray(len);
return new InputEncoding(bytes, identity, identity);
}
int[] charToByte = JoniRegexMatcher.buildCharToByte(input);
int[] byteToChar = JoniRegexMatcher.buildByteToChar(input, bytes.length, charToByte);
return new InputEncoding(bytes, charToByte, byteToChar);
}

private static boolean isAscii(String input, int len) {
for (int i = 0; i < len; i++) {
if (input.charAt(i) > 0x7f) return false;
}
return true;
}

private static byte[] asciiToBytes(String input, int len) {
byte[] bytes = new byte[len];
for (int i = 0; i < len; i++) {
bytes[i] = (byte) input.charAt(i);
}
return bytes;
}

String patternDescription() {
return sourcePattern;
}
Expand Down
38 changes: 26 additions & 12 deletions src/main/java/org/perlonjava/runtime/regex/RegexQuoteMeta.java
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Original file line number Diff line number Diff line change
Expand Up @@ -7,8 +7,14 @@

public class RegexQuoteMeta {
private static final int CALL_SITE_WARNING_UNSET = Integer.MIN_VALUE;
private static final ThreadLocal<int[]> CALL_SITE_WARNING_STATE = ThreadLocal.withInitial(() -> new int[]{CALL_SITE_WARNING_UNSET});
private static final ThreadLocal<String[]> CALL_SITE_WARNING_BITS = ThreadLocal.withInitial(() -> new String[]{null});

static final class CallSiteWarningHolder {
int state = CALL_SITE_WARNING_UNSET;
String bits;
}

private static final ThreadLocal<CallSiteWarningHolder> CALL_SITE_WARNING =
ThreadLocal.withInitial(CallSiteWarningHolder::new);
private static final ThreadLocal<String> PARSER_WARNING_BITS = new ThreadLocal<>();
private static final ThreadLocal<String> MATCH_TARGET_NAME = new ThreadLocal<>();

Expand All @@ -17,21 +23,27 @@ public record ConstructionWarningDisposition(boolean enabled, boolean fatal) {
}

public static void setCallSiteWarningState(int state) {
int[] holder = CALL_SITE_WARNING_STATE.get();
if (holder[0] != state) holder[0] = state;
CallSiteWarningHolder h = CALL_SITE_WARNING.get();
if (h.state != state) h.state = state;
}

public static void setCallSiteWarningBits(String bits) {
String[] holder = CALL_SITE_WARNING_BITS.get();
if (holder[0] != bits) holder[0] = bits;
CallSiteWarningHolder h = CALL_SITE_WARNING.get();
if (h.bits != bits) h.bits = bits;
}

public static void setCallSiteWarning(int state, String bits) {
CallSiteWarningHolder h = CALL_SITE_WARNING.get();
if (h.state != state) h.state = state;
if (h.bits != bits) h.bits = bits;
}

public static String getCallSiteWarningBits() {
return CALL_SITE_WARNING_BITS.get()[0];
return CALL_SITE_WARNING.get().bits;
}

public static boolean isCallSiteWarningExplicitlyDisabled() {
int state = CALL_SITE_WARNING_STATE.get()[0];
int state = CALL_SITE_WARNING.get().state;
return state != CALL_SITE_WARNING_UNSET && state < 0;
}

Expand Down Expand Up @@ -61,10 +73,11 @@ static void warnAtConstruction(String message, boolean strictDefault) {
// This warning belongs to construction of the interpolated pattern.
// Retaining it on the cached RuntimeRegex re-emits it for every match
// and can leak a warning-enabled compilation into a no-warnings use.
int state = CALL_SITE_WARNING_STATE.get()[0];
CallSiteWarningHolder h = CALL_SITE_WARNING.get();
int state = h.state;
RuntimeScalar warning = new RuntimeScalar(message);
RuntimeScalar where = new RuntimeScalar("");
String warningBits = CALL_SITE_WARNING_BITS.get()[0];
String warningBits = h.bits;
if (warningBits == null) {
// Synthetic/interpolated regex wrappers do not always have a
// dedicated quote opcode. Use the active statement mask rather
Expand Down Expand Up @@ -93,7 +106,8 @@ static void warnAtConstruction(String message, boolean strictDefault) {
public static ConstructionWarningDisposition constructionWarningDisposition(
String message, boolean strictDefault) {
String category = warningCategory(message);
String warningBits = CALL_SITE_WARNING_BITS.get()[0];
CallSiteWarningHolder h = CALL_SITE_WARNING.get();
String warningBits = h.bits;
if (warningBits == null) {
warningBits = WarningBitsRegistry.getRuntimeWarningBits();
}
Expand All @@ -108,7 +122,7 @@ public static ConstructionWarningDisposition constructionWarningDisposition(
enabled && WarningFlags.isFatalInBits(warningBits, category));
}

int state = CALL_SITE_WARNING_STATE.get()[0];
int state = h.state;
if (state != CALL_SITE_WARNING_UNSET) {
return new ConstructionWarningDisposition(state > 0, state == 2);
}
Expand Down
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