vector_ = static_offsets_vector_;
}
}
-
-
inline ~OffsetsVector() {
if (offsets_vector_length_ > kStaticOffsetsVectorSize) {
DeleteArray(vector_);
vector_ = NULL;
}
}
-
-
- inline int* vector() {
- return vector_;
- }
-
-
- inline int length() {
- return offsets_vector_length_;
- }
+ inline int* vector() { return vector_; }
+ inline int length() { return offsets_vector_length_; }
private:
int* vector_;
}
#endif
LOG(RegExpExecEvent(regexp, previous_index, subject));
+
+ if (!subject->IsFlat(StringShape(*subject))) {
+ FlattenString(subject);
+ }
+
return IrregexpExecOnce(irregexp,
num_captures,
subject,
subject->Flatten(shape);
}
- do {
+ while (true) {
if (previous_index > subject->length() || previous_index < 0) {
// Per ECMA-262 15.10.6.2, if the previous index is greater than the
// string length, there is no match.
matches = Factory::null_value();
+ return result;
} else {
#ifdef DEBUG
if (FLAG_trace_regexp_bytecodes) {
if (offsets.vector()[0] == offsets.vector()[1]) {
previous_index++;
}
+ } else if (matches->IsNull()) {
+ return result;
+ } else {
+ return matches;
}
}
- } while (matches->IsJSArray());
-
- // If we exited the loop with an exception, throw it.
- if (matches->IsNull()) {
- // Exited loop normally.
- return result;
- } else {
- // Exited loop with the exception in matches.
- return matches;
}
}
int previous_index,
int* offsets_vector,
int offsets_vector_length) {
+ ASSERT(subject->IsFlat(StringShape(*subject)));
bool rc;
int tag = Smi::cast(irregexp->get(kIrregexpImplementationIndex))->value();
- if (!subject->IsFlat(StringShape(*subject))) {
- FlattenString(subject);
- }
-
switch (tag) {
case RegExpMacroAssembler::kIA32Implementation: {
#ifndef ARM
Handle<FixedArray> array = Factory::NewFixedArray(2 * (num_captures+1));
// The captures come in (start, end+1) pairs.
- for (int i = 0; i < 2 * (num_captures+1); i += 2) {
+ for (int i = 0; i < 2 * (num_captures + 1); i += 2) {
array->set(i, Smi::FromInt(offsets_vector[i]));
- array->set(i+1, Smi::FromInt(offsets_vector[i+1]));
+ array->set(i + 1, Smi::FromInt(offsets_vector[i + 1]));
}
return Factory::NewJSArrayWithElements(array);
}
}
-void GenerationVariant::PushAffectedRegisters(RegExpMacroAssembler* macro,
+void GenerationVariant::PushAffectedRegisters(RegExpMacroAssembler* assembler,
int max_register,
OutSet& affected_registers) {
for (int reg = 0; reg <= max_register; reg++) {
- if (affected_registers.Get(reg)) macro->PushRegister(reg);
+ if (affected_registers.Get(reg)) assembler->PushRegister(reg);
}
}
-void GenerationVariant::RestoreAffectedRegisters(RegExpMacroAssembler* macro,
- int max_register,
- OutSet& affected_registers) {
+void GenerationVariant::RestoreAffectedRegisters(
+ RegExpMacroAssembler* assembler,
+ int max_register,
+ OutSet& affected_registers) {
for (int reg = max_register; reg >= 0; reg--) {
- if (affected_registers.Get(reg)) macro->PopRegister(reg);
+ if (affected_registers.Get(reg)) assembler->PopRegister(reg);
}
}
-void GenerationVariant::PerformDeferredActions(RegExpMacroAssembler* macro,
+void GenerationVariant::PerformDeferredActions(RegExpMacroAssembler* assembler,
int max_register,
OutSet& affected_registers) {
for (int reg = 0; reg <= max_register; reg++) {
}
}
if (store_position != -1) {
- macro->WriteCurrentPositionToRegister(reg, store_position);
+ assembler->WriteCurrentPositionToRegister(reg, store_position);
} else {
if (absolute) {
- macro->SetRegister(reg, value);
+ assembler->SetRegister(reg, value);
} else {
if (value != 0) {
- macro->AdvanceRegister(reg, value);
+ assembler->AdvanceRegister(reg, value);
}
}
}
// nodes. It normalises the state of the code generator to ensure we can
// generate generic code.
bool GenerationVariant::Flush(RegExpCompiler* compiler, RegExpNode* successor) {
- RegExpMacroAssembler* macro = compiler->macro_assembler();
+ RegExpMacroAssembler* assembler = compiler->macro_assembler();
- ASSERT(actions_ != NULL || cp_offset_ != 0 || backtrack() != NULL);
+ ASSERT(actions_ != NULL ||
+ cp_offset_ != 0 ||
+ backtrack() != NULL ||
+ characters_preloaded_ != 0 ||
+ quick_check_performed_.characters() != 0);
if (actions_ == NULL && backtrack() == NULL) {
// Here we just have some deferred cp advances to fix and we are back to
- // a normal situation.
- macro->AdvanceCurrentPosition(cp_offset_);
+ // a normal situation. We may also have to forget some information gained
+ // through a quick check that was already performed.
+ if (cp_offset_ != 0) assembler->AdvanceCurrentPosition(cp_offset_);
// Create a new trivial state and generate the node with that.
GenerationVariant new_state;
return successor->Emit(compiler, &new_state);
// Generate deferred actions here along with code to undo them again.
OutSet affected_registers;
int max_register = FindAffectedRegisters(&affected_registers);
- PushAffectedRegisters(macro, max_register, affected_registers);
- PerformDeferredActions(macro, max_register, affected_registers);
+ PushAffectedRegisters(assembler, max_register, affected_registers);
+ PerformDeferredActions(assembler, max_register, affected_registers);
if (backtrack() != NULL) {
// Here we have a concrete backtrack location. These are set up by choice
// nodes and so they indicate that we have a deferred save of the current
// position which we may need to emit here.
- macro->PushCurrentPosition();
+ assembler->PushCurrentPosition();
}
if (cp_offset_ != 0) {
- macro->AdvanceCurrentPosition(cp_offset_);
+ assembler->AdvanceCurrentPosition(cp_offset_);
}
// Create a new trivial state and generate the node with that.
Label undo;
- macro->PushBacktrack(&undo);
+ assembler->PushBacktrack(&undo);
GenerationVariant new_state;
bool ok = successor->Emit(compiler, &new_state);
// On backtrack we need to restore state.
- macro->Bind(&undo);
+ assembler->Bind(&undo);
if (!ok) return false;
if (backtrack() != NULL) {
- macro->PopCurrentPosition();
+ assembler->PopCurrentPosition();
}
- RestoreAffectedRegisters(macro, max_register, affected_registers);
+ RestoreAffectedRegisters(assembler, max_register, affected_registers);
if (backtrack() == NULL) {
- macro->Backtrack();
+ assembler->Backtrack();
} else {
- macro->GoTo(backtrack());
+ assembler->GoTo(backtrack());
}
return true;
}
-void EndNode::EmitInfoChecks(RegExpMacroAssembler* macro,
+void EndNode::EmitInfoChecks(RegExpMacroAssembler* assembler,
GenerationVariant* variant) {
if (info()->at_end) {
Label succeed;
// LoadCurrentCharacter will go to the label if we are at the end of the
// input string.
- macro->LoadCurrentCharacter(0, &succeed);
- macro->GoTo(variant->backtrack());
- macro->Bind(&succeed);
+ assembler->LoadCurrentCharacter(0, &succeed);
+ assembler->GoTo(variant->backtrack());
+ assembler->Bind(&succeed);
}
}
if (!variant->is_trivial()) {
return variant->Flush(compiler, this);
}
- RegExpMacroAssembler* macro = compiler->macro_assembler();
+ RegExpMacroAssembler* assembler = compiler->macro_assembler();
if (!label()->is_bound()) {
- macro->Bind(label());
+ assembler->Bind(label());
}
- EmitInfoChecks(macro, variant);
- macro->ReadCurrentPositionFromRegister(current_position_register_);
- macro->ReadStackPointerFromRegister(stack_pointer_register_);
+ EmitInfoChecks(assembler, variant);
+ assembler->ReadCurrentPositionFromRegister(current_position_register_);
+ assembler->ReadStackPointerFromRegister(stack_pointer_register_);
// Now that we have unwound the stack we find at the top of the stack the
// backtrack that the BeginSubmatch node got.
- macro->Backtrack();
+ assembler->Backtrack();
return true;
}
if (!variant->is_trivial()) {
return variant->Flush(compiler, this);
}
- RegExpMacroAssembler* macro = compiler->macro_assembler();
+ RegExpMacroAssembler* assembler = compiler->macro_assembler();
if (!label()->is_bound()) {
- macro->Bind(label());
+ assembler->Bind(label());
}
switch (action_) {
case ACCEPT:
- EmitInfoChecks(macro, variant);
- macro->Succeed();
+ EmitInfoChecks(assembler, variant);
+ assembler->Succeed();
return true;
case BACKTRACK:
ASSERT(!info()->at_end);
- macro->GoTo(variant->backtrack());
+ assembler->GoTo(variant->backtrack());
return true;
case NEGATIVE_SUBMATCH_SUCCESS:
// This case is handled in a different virtual method.
static unibrow::Mapping<unibrow::CanonicalizationRange> canonrange;
-static inline void EmitAtomNonLetters(
+// Only emits non-letters (things that don't have case). Only used for case
+// independent matches.
+static inline bool EmitAtomNonLetter(
RegExpMacroAssembler* macro_assembler,
- TextElement elm,
- Vector<const uc16> quarks,
+ uc16 c,
Label* on_failure,
int cp_offset,
- bool check_offset) {
+ bool check,
+ bool preloaded) {
unibrow::uchar chars[unibrow::Ecma262UnCanonicalize::kMaxWidth];
- // It is vital that this loop is backwards due to the unchecked character
- // load below.
- for (int i = quarks.length() - 1; i >= 0; i--) {
- uc16 c = quarks[i];
- int length = uncanonicalize.get(c, '\0', chars);
- if (length <= 1) {
- if (check_offset && i == quarks.length() - 1) {
- macro_assembler->LoadCurrentCharacter(cp_offset + i, on_failure);
- } else {
- // Here we don't need to check against the end of the input string
- // since this character lies before a character that matched.
- macro_assembler->LoadCurrentCharacterUnchecked(cp_offset + i);
- }
- macro_assembler->CheckNotCharacter(c, on_failure);
+ int length = uncanonicalize.get(c, '\0', chars);
+ bool checked = false;
+ if (length <= 1) {
+ if (!preloaded) {
+ macro_assembler->LoadCurrentCharacter(cp_offset, on_failure, check);
+ checked = check;
}
+ macro_assembler->CheckNotCharacter(c, on_failure);
}
+ return checked;
}
// If c1 and c2 differ only by one bit.
// Ecma262UnCanonicalize always gives the highest number last.
ASSERT(c2 > c1);
- macro_assembler->CheckNotCharacterAfterOr(c2, exor, on_failure);
+ uc16 mask = String::kMaxUC16CharCode ^ exor;
+ macro_assembler->CheckNotCharacterAfterAnd(c1, mask, on_failure);
return true;
}
ASSERT(c2 > c1);
// subtract the difference from the found character, then do the or
// trick. We avoid the theoretical case where negative numbers are
// involved in order to simplify code generation.
- macro_assembler->CheckNotCharacterAfterMinusOr(c2 - diff,
- diff,
- on_failure);
+ uc16 mask = String::kMaxUC16CharCode ^ diff;
+ macro_assembler->CheckNotCharacterAfterMinusAnd(c1 - diff,
+ diff,
+ mask,
+ on_failure);
return true;
}
return false;
}
-static inline void EmitAtomLetters(
+// Only emits letters (things that have case). Only used for case independent
+// matches.
+static inline bool EmitAtomLetter(
RegExpMacroAssembler* macro_assembler,
- TextElement elm,
- Vector<const uc16> quarks,
+ uc16 c,
Label* on_failure,
int cp_offset,
- bool check_offset) {
+ bool check,
+ bool preloaded) {
unibrow::uchar chars[unibrow::Ecma262UnCanonicalize::kMaxWidth];
- // It is vital that this loop is backwards due to the unchecked character
- // load below.
- for (int i = quarks.length() - 1; i >= 0; i--) {
- uc16 c = quarks[i];
- int length = uncanonicalize.get(c, '\0', chars);
- if (length <= 1) continue;
- if (check_offset && i == quarks.length() - 1) {
- macro_assembler->LoadCurrentCharacter(cp_offset + i, on_failure);
- } else {
- // Here we don't need to check against the end of the input string
- // since this character lies before a character that matched.
- macro_assembler->LoadCurrentCharacterUnchecked(cp_offset + i);
- }
- Label ok;
- ASSERT(unibrow::Ecma262UnCanonicalize::kMaxWidth == 4);
- switch (length) {
- case 2: {
- if (ShortCutEmitCharacterPair(macro_assembler,
- chars[0],
- chars[1],
- on_failure)) {
- } else {
- macro_assembler->CheckCharacter(chars[0], &ok);
- macro_assembler->CheckNotCharacter(chars[1], on_failure);
- macro_assembler->Bind(&ok);
- }
- break;
- }
- case 4:
- macro_assembler->CheckCharacter(chars[3], &ok);
- // Fall through!
- case 3:
+ int length = uncanonicalize.get(c, '\0', chars);
+ if (length <= 1) return false;
+ // We may not need to check against the end of the input string
+ // if this character lies before a character that matched.
+ if (!preloaded) {
+ macro_assembler->LoadCurrentCharacter(cp_offset, on_failure, check);
+ }
+ Label ok;
+ ASSERT(unibrow::Ecma262UnCanonicalize::kMaxWidth == 4);
+ switch (length) {
+ case 2: {
+ if (ShortCutEmitCharacterPair(macro_assembler,
+ chars[0],
+ chars[1],
+ on_failure)) {
+ } else {
macro_assembler->CheckCharacter(chars[0], &ok);
- macro_assembler->CheckCharacter(chars[1], &ok);
- macro_assembler->CheckNotCharacter(chars[2], on_failure);
+ macro_assembler->CheckNotCharacter(chars[1], on_failure);
macro_assembler->Bind(&ok);
- break;
- default:
- UNREACHABLE();
- break;
+ }
+ break;
}
+ case 4:
+ macro_assembler->CheckCharacter(chars[3], &ok);
+ // Fall through!
+ case 3:
+ macro_assembler->CheckCharacter(chars[0], &ok);
+ macro_assembler->CheckCharacter(chars[1], &ok);
+ macro_assembler->CheckNotCharacter(chars[2], on_failure);
+ macro_assembler->Bind(&ok);
+ break;
+ default:
+ UNREACHABLE();
+ break;
}
+ return true;
}
int cp_offset,
Label* on_failure,
bool check_offset,
- bool ascii) {
+ bool ascii,
+ bool preloaded) {
ZoneList<CharacterRange>* ranges = cc->ranges();
int max_char;
if (ascii) {
return;
}
- if (check_offset) {
- macro_assembler->LoadCurrentCharacter(cp_offset, on_failure);
- } else {
- // Here we don't need to check against the end of the input string
- // since this character lies before a character that matched.
- macro_assembler->LoadCurrentCharacterUnchecked(cp_offset);
+ if (!preloaded) {
+ macro_assembler->LoadCurrentCharacter(cp_offset, on_failure, check_offset);
}
- for (int i = 0; i <= last_valid_range; i++) {
+ for (int i = 0; i < last_valid_range; i++) {
CharacterRange& range = ranges->at(i);
Label next_range;
uc16 from = range.from();
}
+RegExpNode::~RegExpNode() {
+}
+
+
RegExpNode::LimitResult RegExpNode::LimitVersions(RegExpCompiler* compiler,
GenerationVariant* variant) {
// TODO(erikcorry): Implement support.
}
-// This generates the code to match a text node. A text node can contain
-// straight character sequences (possibly to be matched in a case-independent
-// way) and character classes. In order to be most efficient we test for the
-// simple things first and then move on to the more complicated things. The
-// simplest thing is a non-letter or a letter if we are matching case. The
-// next-most simple thing is a case-independent letter. The least simple is
-// a character class. Another optimization is that we test the last one first.
-// If that succeeds we don't need to test for the end of the string when we
-// load other characters.
-bool TextNode::Emit(RegExpCompiler* compiler, GenerationVariant* variant) {
- RegExpMacroAssembler* macro_assembler = compiler->macro_assembler();
- Label *backtrack = variant->backtrack();
- LimitResult limit_result = LimitVersions(compiler, variant);
- if (limit_result == FAIL) return false;
- if (limit_result == DONE) return true;
- ASSERT(limit_result == CONTINUE);
+int ActionNode::EatsAtLeast(int recursion_depth) {
+ if (recursion_depth > RegExpCompiler::kMaxRecursion) return 0;
+ if (type_ == POSITIVE_SUBMATCH_SUCCESS) return 0; // Rewinds input!
+ return on_success()->EatsAtLeast(recursion_depth + 1);
+}
- int element_count = elms_->length();
- ASSERT(element_count != 0);
- if (info()->at_end) {
- macro_assembler->GoTo(backtrack);
- return true;
+
+int TextNode::EatsAtLeast(int recursion_depth) {
+ int answer = Length();
+ if (answer >= 4) return answer;
+ if (recursion_depth > RegExpCompiler::kMaxRecursion) return answer;
+ return answer + on_success()->EatsAtLeast(recursion_depth + 1);
+}
+
+
+int ChoiceNode::EatsAtLeastHelper(int recursion_depth,
+ RegExpNode* ignore_this_node) {
+ if (recursion_depth > RegExpCompiler::kMaxRecursion) return 0;
+ int min = 100;
+ int choice_count = alternatives_->length();
+ for (int i = 0; i < choice_count; i++) {
+ RegExpNode* node = alternatives_->at(i).node();
+ if (node == ignore_this_node) continue;
+ int node_eats_at_least = node->EatsAtLeast(recursion_depth + 1);
+ if (node_eats_at_least < min) min = node_eats_at_least;
+ }
+ return min;
+}
+
+
+int LoopChoiceNode::EatsAtLeast(int recursion_depth) {
+ return EatsAtLeastHelper(recursion_depth, loop_node_);
+}
+
+
+int ChoiceNode::EatsAtLeast(int recursion_depth) {
+ return EatsAtLeastHelper(recursion_depth, NULL);
+}
+
+
+// Takes the left-most 1-bit and smears it out, setting all bits to its right.
+static inline uint32_t SmearBitsRight(uint32_t v) {
+ v |= v >> 1;
+ v |= v >> 2;
+ v |= v >> 4;
+ v |= v >> 8;
+ v |= v >> 16;
+ return v;
+}
+
+
+bool QuickCheckDetails::Rationalize(bool asc) {
+ bool found_useful_op = false;
+ uint32_t char_mask;
+ if (asc) {
+ char_mask = String::kMaxAsciiCharCode;
+ } else {
+ char_mask = String::kMaxUC16CharCode;
+ }
+ mask_ = 0;
+ value_ = 0;
+ int char_shift = 0;
+ for (int i = 0; i < characters_; i++) {
+ Position* pos = &positions_[i];
+ if ((pos->mask & String::kMaxAsciiCharCode) != 0) {
+ found_useful_op = true;
+ }
+ mask_ |= (pos->mask & char_mask) << char_shift;
+ value_ |= (pos->value & char_mask) << char_shift;
+ char_shift += asc ? 8 : 16;
+ }
+ return found_useful_op;
+}
+
+
+bool RegExpNode::EmitQuickCheck(RegExpCompiler* compiler,
+ GenerationVariant* variant,
+ bool preload_has_checked_bounds,
+ Label* on_possible_success,
+ QuickCheckDetails* details,
+ bool fall_through_on_failure) {
+ if (details->characters() == 0) return false;
+ GetQuickCheckDetails(details, compiler, 0);
+ if (!details->Rationalize(compiler->ascii())) return false;
+ uint32_t mask = details->mask();
+ uint32_t value = details->value();
+
+ RegExpMacroAssembler* assembler = compiler->macro_assembler();
+
+ if (variant->characters_preloaded() != details->characters()) {
+ assembler->LoadCurrentCharacter(variant->cp_offset(),
+ variant->backtrack(),
+ !preload_has_checked_bounds,
+ details->characters());
+ }
+
+
+ bool need_mask = true;
+
+ if (details->characters() == 1) {
+ // If number of characters preloaded is 1 then we used a byte or 16 bit
+ // load so the value is already masked down.
+ uint32_t char_mask;
+ if (compiler->ascii()) {
+ char_mask = String::kMaxAsciiCharCode;
+ } else {
+ char_mask = String::kMaxUC16CharCode;
+ }
+ if ((mask & char_mask) == char_mask) need_mask = false;
+ } else {
+ // For 2-character preloads in ASCII mode we also use a 16 bit load with
+ // zero extend.
+ if (details->characters() == 2 && compiler->ascii()) {
+ if ((mask & 0xffff) == 0xffff) need_mask = false;
+ } else {
+ if (mask == 0xffffffff) need_mask = false;
+ }
}
- // First check for non-ASCII text.
- // TODO(plesner): We should do this at node level.
+
+ if (fall_through_on_failure) {
+ if (need_mask) {
+ assembler->CheckCharacterAfterAnd(value, mask, on_possible_success);
+ } else {
+ assembler->CheckCharacter(value, on_possible_success);
+ }
+ } else {
+ if (need_mask) {
+ assembler->CheckNotCharacterAfterAnd(value, mask, variant->backtrack());
+ } else {
+ assembler->CheckNotCharacter(value, variant->backtrack());
+ }
+ }
+ return true;
+}
+
+
+// Here is the meat of GetQuickCheckDetails (see also the comment on the
+// super-class in the .h file).
+//
+// We iterate along the text object, building up for each character a
+// mask and value that can be used to test for a quick failure to match.
+// The masks and values for the positions will be combined into a single
+// machine word for the current character width in order to be used in
+// generating a quick check.
+void TextNode::GetQuickCheckDetails(QuickCheckDetails* details,
+ RegExpCompiler* compiler,
+ int characters_filled_in) {
+ ASSERT(characters_filled_in < details->characters());
+ int characters = details->characters();
+ int char_mask;
+ int char_shift;
if (compiler->ascii()) {
- for (int i = element_count - 1; i >= 0; i--) {
- TextElement elm = elms_->at(i);
- if (elm.type == TextElement::ATOM) {
- Vector<const uc16> quarks = elm.data.u_atom->data();
- for (int j = quarks.length() - 1; j >= 0; j--) {
- if (quarks[j] > String::kMaxAsciiCharCode) {
- macro_assembler->GoTo(backtrack);
- return true;
+ char_mask = String::kMaxAsciiCharCode;
+ char_shift = 8;
+ } else {
+ char_mask = String::kMaxUC16CharCode;
+ char_shift = 16;
+ }
+ for (int k = 0; k < elms_->length(); k++) {
+ TextElement elm = elms_->at(k);
+ if (elm.type == TextElement::ATOM) {
+ Vector<const uc16> quarks = elm.data.u_atom->data();
+ for (int i = 0; i < characters && i < quarks.length(); i++) {
+ QuickCheckDetails::Position* pos =
+ details->positions(characters_filled_in);
+ if (compiler->ignore_case()) {
+ unibrow::uchar chars[unibrow::Ecma262UnCanonicalize::kMaxWidth];
+ uc16 c = quarks[i];
+ int length = uncanonicalize.get(c, '\0', chars);
+ if (length < 2) {
+ // This letter has no case equivalents, so it's nice and simple
+ // and the mask-compare will determine definitely whether we have
+ // a match at this character position.
+ pos->mask = char_mask;
+ pos->value = c;
+ pos->determines_perfectly = true;
+ } else {
+ uint32_t common_bits = char_mask;
+ uint32_t bits = chars[0];
+ for (int j = 1; j < length; j++) {
+ uint32_t differing_bits = ((chars[j] & common_bits) ^ bits);
+ common_bits ^= differing_bits;
+ bits &= common_bits;
+ }
+ // If length is 2 and common bits has only one zero in it then
+ // our mask and compare instruction will determine definitely
+ // whether we have a match at this character position. Otherwise
+ // it can only be an approximate check.
+ uint32_t one_zero = (common_bits | ~char_mask);
+ if (length == 2 && ((~one_zero) & ((~one_zero) - 1)) == 0) {
+ pos->determines_perfectly = true;
+ }
+ pos->mask = common_bits;
+ pos->value = bits;
}
+ } else {
+ // Don't ignore case. Nice simple case where the mask-compare will
+ // determine definitely whether we have a match at this character
+ // position.
+ pos->mask = char_mask;
+ pos->value = quarks[i];
+ pos->determines_perfectly = true;
+ }
+ characters_filled_in++;
+ ASSERT(characters_filled_in <= details->characters());
+ if (characters_filled_in == details->characters()) {
+ return;
}
+ }
+ } else {
+ QuickCheckDetails::Position* pos =
+ details->positions(characters_filled_in);
+ RegExpCharacterClass* tree = elm.data.u_char_class;
+ ZoneList<CharacterRange>* ranges = tree->ranges();
+ CharacterRange range = ranges->at(0);
+ if (tree->is_negated()) {
+ // A quick check uses multi-character mask and compare. There is no
+ // useful way to incorporate a negative char class into this scheme
+ // so we just conservatively create a mask and value that will always
+ // succeed.
+ pos->mask = 0;
+ pos->value = 0;
} else {
- ASSERT_EQ(elm.type, TextElement::CHAR_CLASS);
+ uint32_t differing_bits = (range.from() ^ range.to());
+ // A mask and compare is only perfect if the differing bits form a
+ // number like 00011111 with one single block of trailing 1s.
+ if ((differing_bits & (differing_bits + 1)) == 0) {
+ pos->determines_perfectly = true;
+ }
+ uint32_t common_bits = ~SmearBitsRight(differing_bits);
+ uint32_t bits = (range.from() & common_bits);
+ for (int i = 1; i < ranges->length(); i++) {
+ // Here we are combining more ranges into the mask and compare
+ // value. With each new range the mask becomes more sparse and
+ // so the chances of a false positive rise. A character class
+ // with multiple ranges is assumed never to be equivalent to a
+ // mask and compare operation.
+ pos->determines_perfectly = false;
+ CharacterRange range = ranges->at(i);
+ uint32_t new_common_bits = (range.from() ^ range.to());
+ new_common_bits = ~SmearBitsRight(new_common_bits);
+ common_bits &= new_common_bits;
+ bits &= new_common_bits;
+ uint32_t differing_bits = (range.from() & common_bits) ^ bits;
+ common_bits ^= differing_bits;
+ bits &= common_bits;
+ }
+ pos->mask = common_bits;
+ pos->value = bits;
+ }
+ characters_filled_in++;
+ ASSERT(characters_filled_in <= details->characters());
+ if (characters_filled_in == details->characters()) {
+ return;
}
}
}
- // Second, handle straight character matches.
- int checked_up_to = -1;
- for (int i = element_count - 1; i >= 0; i--) {
+ ASSERT(characters_filled_in != details->characters());
+ on_success()-> GetQuickCheckDetails(details, compiler, characters_filled_in);
+}
+
+
+void QuickCheckDetails::Clear() {
+ for (int i = 0; i < characters_; i++) {
+ positions_[i].mask = 0;
+ positions_[i].value = 0;
+ positions_[i].determines_perfectly = false;
+ }
+ characters_ = 0;
+}
+
+
+void QuickCheckDetails::Advance(int by, bool ascii) {
+ ASSERT(by > 0);
+ if (by >= characters_) {
+ Clear();
+ return;
+ }
+ for (int i = 0; i < characters_ - by; i++) {
+ positions_[i] = positions_[by + i];
+ }
+ for (int i = characters_ - by; i < characters_; i++) {
+ positions_[i].mask = 0;
+ positions_[i].value = 0;
+ positions_[i].determines_perfectly = false;
+ }
+ characters_ -= by;
+ // We could change mask_ and value_ here but we would never advance unless
+ // they had already been used in a check and they won't be used again because
+ // it would gain us nothing. So there's no point.
+}
+
+
+void QuickCheckDetails::Merge(QuickCheckDetails* other, int from_index) {
+ ASSERT(characters_ == other->characters_);
+ for (int i = from_index; i < characters_; i++) {
+ QuickCheckDetails::Position* pos = positions(i);
+ QuickCheckDetails::Position* other_pos = other->positions(i);
+ if (pos->mask != other_pos->mask ||
+ pos->value != other_pos->value ||
+ !other_pos->determines_perfectly) {
+ // Our mask-compare operation will be approximate unless we have the
+ // exact same operation on both sides of the alternation.
+ pos->determines_perfectly = false;
+ }
+ pos->mask &= other_pos->mask;
+ pos->value &= pos->mask;
+ other_pos->value &= pos->mask;
+ uc16 differing_bits = (pos->value ^ other_pos->value);
+ pos->mask &= ~differing_bits;
+ pos->value &= pos->mask;
+ }
+}
+
+
+void LoopChoiceNode::GetQuickCheckDetails(QuickCheckDetails* details,
+ RegExpCompiler* compiler,
+ int characters_filled_in) {
+ if (body_can_be_zero_length_) return;
+ return ChoiceNode::GetQuickCheckDetails(details,
+ compiler,
+ characters_filled_in);
+}
+
+
+void ChoiceNode::GetQuickCheckDetails(QuickCheckDetails* details,
+ RegExpCompiler* compiler,
+ int characters_filled_in) {
+ int choice_count = alternatives_->length();
+ ASSERT(choice_count > 0);
+ alternatives_->at(0).node()->GetQuickCheckDetails(details,
+ compiler,
+ characters_filled_in);
+ for (int i = 1; i < choice_count; i++) {
+ QuickCheckDetails new_details(details->characters());
+ RegExpNode* node = alternatives_->at(i).node();
+ node->GetQuickCheckDetails(&new_details, compiler, characters_filled_in);
+ // Here we merge the quick match details of the two branches.
+ details->Merge(&new_details, characters_filled_in);
+ }
+}
+
+
+// We call this repeatedly to generate code for each pass over the text node.
+// The passes are in increasing order of difficulty because we hope one
+// of the first passes will fail in which case we are saved the work of the
+// later passes. for example for the case independent regexp /%[asdfghjkl]a/
+// we will check the '%' in the first pass, the case independent 'a' in the
+// second pass and the character class in the last pass.
+//
+// The passes are done from right to left, so for example to test for /bar/
+// we will first test for an 'r' with offset 2, then an 'a' with offset 1
+// and then a 'b' with offset 0. This means we can avoid the end-of-input
+// bounds check most of the time. In the example we only need to check for
+// end-of-input when loading the putative 'r'.
+//
+// A slight complication involves the fact that the first character may already
+// be fetched into a register by the previous node. In this case we want to
+// do the test for that character first. We do this in separate passes. The
+// 'preloaded' argument indicates that we are doing such a 'pass'. If such a
+// pass has been performed then subsequent passes will have true in
+// first_element_checked to indicate that that character does not need to be
+// checked again.
+//
+// In addition to all this we are passed a GenerationVariant, which can
+// contain an AlternativeGeneration object. In this AlternativeGeneration
+// object we can see details of any quick check that was already passed in
+// order to get to the code we are now generating. The quick check can involve
+// loading characters, which means we do not need to recheck the bounds
+// up to the limit the quick check already checked. In addition the quick
+// check can have involved a mask and compare operation which may simplify
+// or obviate the need for further checks at some character positions.
+void TextNode::TextEmitPass(RegExpCompiler* compiler,
+ TextEmitPassType pass,
+ bool preloaded,
+ GenerationVariant* variant,
+ bool first_element_checked,
+ int* checked_up_to) {
+ RegExpMacroAssembler* assembler = compiler->macro_assembler();
+ bool ascii = compiler->ascii();
+ Label* backtrack = variant->backtrack();
+ QuickCheckDetails* quick_check = variant->quick_check_performed();
+ int element_count = elms_->length();
+ for (int i = preloaded ? 0 : element_count - 1; i >= 0; i--) {
TextElement elm = elms_->at(i);
- ASSERT(elm.cp_offset >= 0);
int cp_offset = variant->cp_offset() + elm.cp_offset;
if (elm.type == TextElement::ATOM) {
- Vector<const uc16> quarks = elm.data.u_atom->data();
- int last_cp_offset = cp_offset + quarks.length();
- if (compiler->ignore_case()) {
- EmitAtomNonLetters(macro_assembler,
- elm,
- quarks,
- backtrack,
- cp_offset,
- checked_up_to < last_cp_offset);
- } else {
- macro_assembler->CheckCharacters(quarks,
- cp_offset,
- backtrack,
- checked_up_to < last_cp_offset);
+ if (pass == NON_ASCII_MATCH ||
+ pass == CHARACTER_MATCH ||
+ pass == CASE_CHARACTER_MATCH) {
+ Vector<const uc16> quarks = elm.data.u_atom->data();
+ for (int j = preloaded ? 0 : quarks.length() - 1; j >= 0; j--) {
+ bool bound_checked = true; // Most ops will check their bounds.
+ if (first_element_checked && i == 0 && j == 0) continue;
+ if (quick_check != NULL &&
+ elm.cp_offset + j < quick_check->characters() &&
+ quick_check->positions(elm.cp_offset + j)->determines_perfectly) {
+ continue;
+ }
+ if (pass == NON_ASCII_MATCH) {
+ ASSERT(ascii);
+ if (quarks[j] > String::kMaxAsciiCharCode) {
+ assembler->GoTo(backtrack);
+ return;
+ }
+ } else if (pass == CHARACTER_MATCH) {
+ if (compiler->ignore_case()) {
+ bound_checked = EmitAtomNonLetter(assembler,
+ quarks[j],
+ backtrack,
+ cp_offset + j,
+ *checked_up_to < cp_offset + j,
+ preloaded);
+ } else {
+ if (!preloaded) {
+ assembler->LoadCurrentCharacter(cp_offset + j,
+ backtrack,
+ *checked_up_to < cp_offset + j);
+ }
+ assembler->CheckNotCharacter(quarks[j], backtrack);
+ }
+ } else {
+ ASSERT_EQ(pass, CASE_CHARACTER_MATCH);
+ ASSERT(compiler->ignore_case());
+ bound_checked = EmitAtomLetter(assembler,
+ quarks[j],
+ backtrack,
+ cp_offset + j,
+ *checked_up_to < cp_offset + j,
+ preloaded);
+ }
+ if (pass != NON_ASCII_MATCH && bound_checked) {
+ if (cp_offset + j > *checked_up_to) {
+ *checked_up_to = cp_offset + j;
+ }
+ }
+ }
}
- if (last_cp_offset > checked_up_to) checked_up_to = last_cp_offset - 1;
} else {
ASSERT_EQ(elm.type, TextElement::CHAR_CLASS);
- }
- }
- // Third, handle case independent letter matches if any.
- if (compiler->ignore_case()) {
- for (int i = element_count - 1; i >= 0; i--) {
- TextElement elm = elms_->at(i);
- int cp_offset = variant->cp_offset() + elm.cp_offset;
- if (elm.type == TextElement::ATOM) {
- Vector<const uc16> quarks = elm.data.u_atom->data();
- int last_cp_offset = cp_offset + quarks.length();
- EmitAtomLetters(macro_assembler,
- elm,
- quarks,
- backtrack,
- cp_offset,
- checked_up_to < last_cp_offset);
- if (last_cp_offset > checked_up_to) checked_up_to = last_cp_offset - 1;
+ if (first_element_checked && i == 0) continue;
+ if (quick_check != NULL &&
+ elm.cp_offset < quick_check->characters() &&
+ quick_check->positions(elm.cp_offset)->determines_perfectly) {
+ continue;
+ }
+ if (pass == CHARACTER_CLASS_MATCH) {
+ RegExpCharacterClass* cc = elm.data.u_char_class;
+ EmitCharClass(assembler,
+ cc,
+ cp_offset,
+ backtrack,
+ *checked_up_to < cp_offset,
+ ascii,
+ preloaded);
+ if (cp_offset > *checked_up_to) {
+ *checked_up_to = cp_offset;
+ }
}
}
}
- // If the fast character matches passed then do the character classes.
- for (int i = element_count - 1; i >= 0; i--) {
- TextElement elm = elms_->at(i);
- int cp_offset = variant->cp_offset() + elm.cp_offset;
- if (elm.type == TextElement::CHAR_CLASS) {
- RegExpCharacterClass* cc = elm.data.u_char_class;
- EmitCharClass(macro_assembler,
- cc,
- cp_offset,
- backtrack,
- checked_up_to < cp_offset,
- compiler->ascii());
- if (cp_offset > checked_up_to) checked_up_to = cp_offset;
- }
+}
+
+
+int TextNode::Length() {
+ TextElement elm = elms_->last();
+ ASSERT(elm.cp_offset >= 0);
+ if (elm.type == TextElement::ATOM) {
+ return elm.cp_offset + elm.data.u_atom->data().length();
+ } else {
+ return elm.cp_offset + 1;
+ }
+}
+
+
+// This generates the code to match a text node. A text node can contain
+// straight character sequences (possibly to be matched in a case-independent
+// way) and character classes. For efficiency we do not do this in a single
+// pass from left to right. Instead we pass over the text node several times,
+// emitting code for some character positions every time. See the comment on
+// TextEmitPass for details.
+bool TextNode::Emit(RegExpCompiler* compiler, GenerationVariant* variant) {
+ LimitResult limit_result = LimitVersions(compiler, variant);
+ if (limit_result == FAIL) return false;
+ if (limit_result == DONE) return true;
+ ASSERT(limit_result == CONTINUE);
+
+ if (info()->follows_word_interest ||
+ info()->follows_newline_interest ||
+ info()->follows_start_interest) {
+ return false;
+ }
+
+ if (info()->at_end) {
+ compiler->macro_assembler()->GoTo(variant->backtrack());
+ return true;
}
- GenerationVariant new_variant(*variant);
- new_variant.set_cp_offset(checked_up_to + 1);
+ if (compiler->ascii()) {
+ int dummy = 0;
+ TextEmitPass(compiler, NON_ASCII_MATCH, false, variant, false, &dummy);
+ }
+
+ bool first_elt_done = false;
+ int bound_checked_to = variant->cp_offset() - 1;
+ QuickCheckDetails* quick_check = variant->quick_check_performed();
+ bound_checked_to += Max(quick_check->characters(),
+ variant->characters_preloaded());
+
+ // If a character is preloaded into the current character register then
+ // check that now.
+ if (variant->characters_preloaded() == 1) {
+ TextEmitPass(compiler,
+ CHARACTER_MATCH,
+ true,
+ variant,
+ false,
+ &bound_checked_to);
+ if (compiler->ignore_case()) {
+ TextEmitPass(compiler,
+ CASE_CHARACTER_MATCH,
+ true,
+ variant,
+ false,
+ &bound_checked_to);
+ }
+ TextEmitPass(compiler,
+ CHARACTER_CLASS_MATCH,
+ true,
+ variant,
+ false,
+ &bound_checked_to);
+ first_elt_done = true;
+ }
+
+ TextEmitPass(compiler,
+ CHARACTER_MATCH,
+ false,
+ variant,
+ first_elt_done,
+ &bound_checked_to);
+ if (compiler->ignore_case()) {
+ TextEmitPass(compiler,
+ CASE_CHARACTER_MATCH,
+ false,
+ variant,
+ first_elt_done,
+ &bound_checked_to);
+ }
+ TextEmitPass(compiler,
+ CHARACTER_CLASS_MATCH,
+ false,
+ variant,
+ first_elt_done,
+ &bound_checked_to);
+
+ GenerationVariant successor_variant(*variant);
+ successor_variant.AdvanceVariant(Length(), compiler->ascii());
RecursionCheck rc(compiler);
- return on_success()->Emit(compiler, &new_variant);
+ return on_success()->Emit(compiler, &successor_variant);
+}
+
+
+void GenerationVariant::AdvanceVariant(int by, bool ascii) {
+ ASSERT(by > 0);
+ // We don't have an instruction for shifting the current character register
+ // down or for using a shifted value for anything so lets just forget that
+ // we preloaded any characters into it.
+ characters_preloaded_ = 0;
+ // Adjust the offsets of the quick check performed information. This
+ // information is used to find out what we already determined about the
+ // characters by means of mask and compare.
+ quick_check_performed_.Advance(by, ascii);
+ cp_offset_ += by;
}
}
+int ChoiceNode::CalculatePreloadCharacters(RegExpCompiler* compiler) {
+ bool ascii = compiler->ascii();
+ int preload_characters = EatsAtLeast(0);
+#ifdef CAN_READ_UNALIGNED
+ if (ascii) {
+ if (preload_characters > 4) preload_characters = 4;
+ // We can't preload 3 characters because there is no machine instruction
+ // to do that. We can't just load 4 because we could be reading
+ // beyond the end of the string, which could cause a memory fault.
+ if (preload_characters == 3) preload_characters = 2;
+ } else {
+ if (preload_characters > 2) preload_characters = 2;
+ }
+#else
+ if (preload_characters > 1) preload_characters = 1;
+#endif
+ return preload_characters;
+}
+
+
+// This class is used when generating the alternatives in a choice node. It
+// records the way the alternative is being code generated.
+class AlternativeGeneration: public Malloced {
+ public:
+ AlternativeGeneration()
+ : possible_success(),
+ expects_preload(false),
+ after(),
+ quick_check_details() { }
+ Label possible_success;
+ bool expects_preload;
+ Label after;
+ QuickCheckDetails quick_check_details;
+};
+
+
+// Creates a list of AlternativeGenerations. If the list has a reasonable
+// size then it is on the stack, otherwise the excess is on the heap.
+class AlternativeGenerationList {
+ public:
+ explicit AlternativeGenerationList(int count)
+ : alt_gens_(count) {
+ for (int i = 0; i < count && i < kAFew; i++) {
+ alt_gens_.Add(a_few_alt_gens_ + i);
+ }
+ for (int i = kAFew; i < count; i++) {
+ alt_gens_.Add(new AlternativeGeneration());
+ }
+ }
+ ~AlternativeGenerationList() {
+ for (int i = 0; i < alt_gens_.length(); i++) {
+ alt_gens_[i]->possible_success.Unuse();
+ alt_gens_[i]->after.Unuse();
+ }
+ for (int i = kAFew; i < alt_gens_.length(); i++) {
+ delete alt_gens_[i];
+ alt_gens_[i] = NULL;
+ }
+ }
+
+ AlternativeGeneration* at(int i) {
+ return alt_gens_[i];
+ }
+ private:
+ static const int kAFew = 10;
+ ZoneList<AlternativeGeneration*> alt_gens_;
+ AlternativeGeneration a_few_alt_gens_[kAFew];
+};
+
+
+/* Code generation for choice nodes.
+ *
+ * We generate quick checks that do a mask and compare to eliminate a
+ * choice. If the quick check succeeds then it jumps to the continuation to
+ * do slow checks and check subsequent nodes. If it fails (the common case)
+ * it falls through to the next choice.
+ *
+ * Here is the desired flow graph. Nodes directly below each other imply
+ * fallthrough. Alternatives 1 and 2 have quick checks. Alternative
+ * 3 doesn't have a quick check so we have to call the slow check.
+ * Nodes are marked Qn for quick checks and Sn for slow checks. The entire
+ * regexp continuation is generated directly after the Sn node, up to the
+ * next GoTo if we decide to reuse some already generated code. Some
+ * nodes expect preload_characters to be preloaded into the current
+ * character register. R nodes do this preloading. Vertices are marked
+ * F for failures and S for success (possible success in the case of quick
+ * nodes). L, V, < and > are used as arrow heads.
+ *
+ * ----------> R
+ * |
+ * V
+ * Q1 -----> S1
+ * | S /
+ * F| /
+ * | F/
+ * | /
+ * | R
+ * | /
+ * V L
+ * Q2 -----> S2
+ * | S /
+ * F| /
+ * | F/
+ * | /
+ * | R
+ * | /
+ * V L
+ * S3
+ * |
+ * F|
+ * |
+ * R
+ * |
+ * backtrack V
+ * <----------Q4
+ * \ F |
+ * \ |S
+ * \ F V
+ * \-----S4
+ *
+ * For greedy loops we reverse our expectation and expect to match rather
+ * than fail. Therefore we want the loop code to look like this (U is the
+ * unwind code that steps back in the greedy loop). The following alternatives
+ * look the same as above.
+ * _____
+ * / \
+ * V |
+ * ----------> S1 |
+ * /| |
+ * / |S |
+ * F/ \_____/
+ * /
+ * |<-----------
+ * | \
+ * V \
+ * Q2 ---> S2 \
+ * | S / |
+ * F| / |
+ * | F/ |
+ * | / |
+ * | R |
+ * | / |
+ * F VL |
+ * <------U |
+ * back |S |
+ * \______________/
+ */
+
+
bool ChoiceNode::Emit(RegExpCompiler* compiler, GenerationVariant* variant) {
RegExpMacroAssembler* macro_assembler = compiler->macro_assembler();
int choice_count = alternatives_->length();
int text_length = GreedyLoopTextLength(&(alternatives_->at(0)));
bool greedy_loop = false;
Label greedy_loop_label;
- GenerationVariant counter_backtrack_variant(&greedy_loop_label);
+ GenerationVariant counter_backtrack_variant;
+ counter_backtrack_variant.set_backtrack(&greedy_loop_label);
if (choice_count > 1 && text_length != kNodeIsTooComplexForGreedyLoops) {
// Here we have special handling for greedy loops containing only text nodes
// and other simple nodes. These are handled by pushing the current
macro_assembler->PushCurrentPosition();
current_variant = &counter_backtrack_variant;
Label greedy_match_failed;
- GenerationVariant greedy_match_variant(&greedy_match_failed);
+ GenerationVariant greedy_match_variant;
+ greedy_match_variant.set_backtrack(&greedy_match_failed);
Label loop_label;
macro_assembler->Bind(&loop_label);
greedy_match_variant.set_stop_node(this);
Label second_choice; // For use in greedy matches.
macro_assembler->Bind(&second_choice);
+ int first_normal_choice = greedy_loop ? 1 : 0;
+
+ int preload_characters = CalculatePreloadCharacters(compiler);
+ bool preload_is_current = false;
+ bool preload_has_checked_bounds = false;
+
+ AlternativeGenerationList alt_gens(choice_count);
+
// For now we just call all choices one after the other. The idea ultimately
// is to use the Dispatch table to try only the relevant ones.
- for (int i = greedy_loop ? 1 : 0; i < choice_count - 1; i++) {
+ for (int i = first_normal_choice; i < choice_count; i++) {
GuardedAlternative alternative = alternatives_->at(i);
- Label after;
+ AlternativeGeneration* alt_gen(alt_gens.at(i));
+ alt_gen->quick_check_details.set_characters(preload_characters);
ZoneList<Guard*>* guards = alternative.guards();
int guard_count = (guards == NULL) ? 0 : guards->length();
+
GenerationVariant new_variant(*current_variant);
- new_variant.set_backtrack(&after);
- for (int j = 0; j < guard_count; j++) {
- GenerateGuard(macro_assembler, guards->at(j), &new_variant);
+ new_variant.set_characters_preloaded(preload_is_current ?
+ preload_characters :
+ 0);
+ new_variant.quick_check_performed()->Clear();
+ alt_gen->expects_preload = preload_is_current;
+ bool generate_full_check_inline = false;
+ if (alternative.node()->EmitQuickCheck(compiler,
+ &new_variant,
+ preload_has_checked_bounds,
+ &alt_gen->possible_success,
+ &alt_gen->quick_check_details,
+ i < choice_count - 1)) {
+ // Quick check was generated for this choice.
+ preload_is_current = true;
+ preload_has_checked_bounds = true;
+ // On the last choice in the ChoiceNode we generated the quick
+ // check to fall through on possible success. So now we need to
+ // generate the full check inline.
+ if (i == choice_count - 1) {
+ macro_assembler->Bind(&alt_gen->possible_success);
+ new_variant.set_quick_check_performed(&alt_gen->quick_check_details);
+ new_variant.set_characters_preloaded(preload_characters);
+ generate_full_check_inline = true;
+ }
+ } else {
+ // No quick check was generated. Put the full code here.
+ if (i < choice_count - 1) {
+ new_variant.set_backtrack(&alt_gen->after);
+ }
+ generate_full_check_inline = true;
}
- if (!alternative.node()->Emit(compiler, &new_variant)) {
- after.Unuse();
- return false;
+ if (generate_full_check_inline) {
+ if (preload_is_current) {
+ new_variant.set_characters_preloaded(preload_characters);
+ }
+ for (int j = 0; j < guard_count; j++) {
+ GenerateGuard(macro_assembler, guards->at(j), &new_variant);
+ }
+ if (!alternative.node()->Emit(compiler, &new_variant)) {
+ greedy_loop_label.Unuse();
+ return false;
+ }
+ preload_is_current = false;
}
- macro_assembler->Bind(&after);
+ macro_assembler->Bind(&alt_gen->after);
}
- GuardedAlternative alternative = alternatives_->at(choice_count - 1);
- ZoneList<Guard*>* guards = alternative.guards();
- int guard_count = (guards == NULL) ? 0 : guards->length();
- for (int j = 0; j < guard_count; j++) {
- GenerateGuard(macro_assembler, guards->at(j), current_variant);
- }
- bool ok = alternative.node()->Emit(compiler, current_variant);
- if (!ok) return false;
if (greedy_loop) {
macro_assembler->Bind(&greedy_loop_label);
// If we have unwound to the bottom then backtrack.
macro_assembler->AdvanceCurrentPosition(-text_length);
macro_assembler->GoTo(&second_choice);
}
+ // At this point we need to generate slow checks for the alternatives where
+ // the quick check was inlined. We can recognize these because the associated
+ // label was bound.
+ for (int i = first_normal_choice; i < choice_count - 1; i++) {
+ AlternativeGeneration* alt_gen = alt_gens.at(i);
+ if (!EmitOutOfLineContinuation(compiler,
+ current_variant,
+ alternatives_->at(i),
+ alt_gen,
+ preload_characters,
+ alt_gens.at(i + 1)->expects_preload)) {
+ return false;
+ }
+ }
return true;
}
+bool ChoiceNode::EmitOutOfLineContinuation(RegExpCompiler* compiler,
+ GenerationVariant* variant,
+ GuardedAlternative alternative,
+ AlternativeGeneration* alt_gen,
+ int preload_characters,
+ bool next_expects_preload) {
+ if (!alt_gen->possible_success.is_linked()) return true;
+
+ RegExpMacroAssembler* macro_assembler = compiler->macro_assembler();
+ macro_assembler->Bind(&alt_gen->possible_success);
+ GenerationVariant out_of_line_variant(*variant);
+ out_of_line_variant.set_characters_preloaded(preload_characters);
+ out_of_line_variant.set_quick_check_performed(&alt_gen->quick_check_details);
+ ZoneList<Guard*>* guards = alternative.guards();
+ int guard_count = (guards == NULL) ? 0 : guards->length();
+ if (next_expects_preload) {
+ Label reload_current_char;
+ out_of_line_variant.set_backtrack(&reload_current_char);
+ for (int j = 0; j < guard_count; j++) {
+ GenerateGuard(macro_assembler, guards->at(j), &out_of_line_variant);
+ }
+ bool ok = alternative.node()->Emit(compiler, &out_of_line_variant);
+ macro_assembler->Bind(&reload_current_char);
+ // Reload the current character, since the next quick check expects that.
+ // We don't need to check bounds here because we only get into this
+ // code through a quick check which already did the checked load.
+ macro_assembler->LoadCurrentCharacter(variant->cp_offset(),
+ NULL,
+ false,
+ preload_characters);
+ macro_assembler->GoTo(&(alt_gen->after));
+ return ok;
+ } else {
+ out_of_line_variant.set_backtrack(&(alt_gen->after));
+ for (int j = 0; j < guard_count; j++) {
+ GenerateGuard(macro_assembler, guards->at(j), &out_of_line_variant);
+ }
+ return alternative.node()->Emit(compiler, &out_of_line_variant);
+ }
+}
+
+
bool ActionNode::Emit(RegExpCompiler* compiler, GenerationVariant* variant) {
- RegExpMacroAssembler* macro = compiler->macro_assembler();
+ RegExpMacroAssembler* assembler = compiler->macro_assembler();
LimitResult limit_result = LimitVersions(compiler, variant);
if (limit_result == DONE) return true;
if (limit_result == FAIL) return false;
}
case BEGIN_SUBMATCH:
if (!variant->is_trivial()) return variant->Flush(compiler, this);
- macro->WriteCurrentPositionToRegister(
+ assembler->WriteCurrentPositionToRegister(
data_.u_submatch.current_position_register, 0);
- macro->WriteStackPointerToRegister(
+ assembler->WriteStackPointerToRegister(
data_.u_submatch.stack_pointer_register);
return on_success()->Emit(compiler, variant);
case POSITIVE_SUBMATCH_SUCCESS:
Label at_end;
// Load current character jumps to the label if we are beyond the string
// end.
- macro->LoadCurrentCharacter(0, &at_end);
- macro->GoTo(variant->backtrack());
- macro->Bind(&at_end);
+ assembler->LoadCurrentCharacter(0, &at_end);
+ assembler->GoTo(variant->backtrack());
+ assembler->Bind(&at_end);
}
- macro->ReadCurrentPositionFromRegister(
+ assembler->ReadCurrentPositionFromRegister(
data_.u_submatch.current_position_register);
- macro->ReadStackPointerFromRegister(
+ assembler->ReadStackPointerFromRegister(
data_.u_submatch.stack_pointer_register);
return on_success()->Emit(compiler, variant);
default:
bool BackReferenceNode::Emit(RegExpCompiler* compiler,
GenerationVariant* variant) {
- RegExpMacroAssembler* macro = compiler->macro_assembler();
+ RegExpMacroAssembler* assembler = compiler->macro_assembler();
if (!variant->is_trivial()) {
return variant->Flush(compiler, this);
}
if (info()->at_end) {
// If we are constrained to match at the end of the input then succeed
// iff the back reference is empty.
- macro->CheckNotRegistersEqual(start_reg_, end_reg_, variant->backtrack());
+ assembler->CheckNotRegistersEqual(start_reg_,
+ end_reg_,
+ variant->backtrack());
} else {
if (compiler->ignore_case()) {
- macro->CheckNotBackReferenceIgnoreCase(start_reg_, variant->backtrack());
+ assembler->CheckNotBackReferenceIgnoreCase(start_reg_,
+ variant->backtrack());
} else {
- macro->CheckNotBackReference(start_reg_, variant->backtrack());
+ assembler->CheckNotBackReference(start_reg_, variant->backtrack());
}
}
return on_success()->Emit(compiler, variant);
bool has_max = max < RegExpTree::kInfinity;
bool needs_counter = has_min || has_max;
int reg_ctr = needs_counter ? compiler->AllocateRegister() : -1;
- LoopChoiceNode* center = new LoopChoiceNode();
+ LoopChoiceNode* center = new LoopChoiceNode(body->min_match() == 0);
RegExpNode* loop_return = needs_counter
? static_cast<RegExpNode*>(ActionNode::IncrementRegister(reg_ctr, center))
: static_cast<RegExpNode*>(center);
};
+// Details of a quick mask-compare check that can look ahead in the
+// input stream.
+class QuickCheckDetails {
+ public:
+ QuickCheckDetails()
+ : characters_(0),
+ mask_(0),
+ value_(0) { }
+ explicit QuickCheckDetails(int characters)
+ : characters_(characters),
+ mask_(0),
+ value_(0) { }
+ bool Rationalize(bool ascii);
+ // Merge in the information from another branch of an alternation.
+ void Merge(QuickCheckDetails* other, int from_index);
+ // Advance the current position by some amount.
+ void Advance(int by, bool ascii);
+ void Clear();
+ struct Position {
+ Position() : mask(0), value(0), determines_perfectly(false) { }
+ uc16 mask;
+ uc16 value;
+ bool determines_perfectly;
+ };
+ int characters() { return characters_; }
+ void set_characters(int characters) { characters_ = characters; }
+ Position* positions(int index) {
+ ASSERT(index >= 0);
+ ASSERT(index < characters_);
+ return positions_ + index;
+ }
+ uint32_t mask() { return mask_; }
+ uint32_t value() { return value_; }
+
+ private:
+ // How many characters do we have quick check information from. This is
+ // the same for all branches of a choice node.
+ int characters_;
+ Position positions_[4];
+ // These values are the condensate of the above array after Rationalize().
+ uint32_t mask_;
+ uint32_t value_;
+};
+
+
class RegExpNode: public ZoneObject {
public:
RegExpNode() : variants_generated_(0) { }
- virtual ~RegExpNode() { }
+ virtual ~RegExpNode();
virtual void Accept(NodeVisitor* visitor) = 0;
// Generates a goto to this node or actually generates the code at this point.
// Until the implementation is complete we will return true for success and
// false for failure.
virtual bool Emit(RegExpCompiler* compiler, GenerationVariant* variant) = 0;
+ // How many characters must this node consume at a minimum in order to
+ // succeed.
+ virtual int EatsAtLeast(int recursion_depth) = 0;
+ // Emits some quick code that checks whether the preloaded characters match.
+ // Falls through on certain failure, jumps to the label on possible success.
+ // If the node cannot make a quick check it does nothing and returns false.
+ bool EmitQuickCheck(RegExpCompiler* compiler,
+ GenerationVariant* variant,
+ bool preload_has_checked_bounds,
+ Label* on_possible_success,
+ QuickCheckDetails* details_return,
+ bool fall_through_on_failure);
+ // For a given number of characters this returns a mask and a value. The
+ // next n characters are anded with the mask and compared with the value.
+ // A comparison failure indicates the node cannot match the next n characters.
+ // A comparison success indicates the node may match.
+ virtual void GetQuickCheckDetails(QuickCheckDetails* details,
+ RegExpCompiler* compiler,
+ int characters_filled_in) = 0;
static const int kNodeIsTooComplexForGreedyLoops = -1;
virtual int GreedyLoopTextLength() { return kNodeIsTooComplexForGreedyLoops; }
Label* label() { return &label_; }
RegExpNode* on_success);
virtual void Accept(NodeVisitor* visitor);
virtual bool Emit(RegExpCompiler* compiler, GenerationVariant* variant);
+ virtual int EatsAtLeast(int recursion_depth);
+ virtual void GetQuickCheckDetails(QuickCheckDetails* details,
+ RegExpCompiler* compiler,
+ int filled_in) {
+ return on_success()->GetQuickCheckDetails(details, compiler, filled_in);
+ }
virtual RegExpNode* PropagateForward(NodeInfo* info);
Type type() { return type_; }
// TODO(erikcorry): We should allow some action nodes in greedy loops.
virtual void Accept(NodeVisitor* visitor);
virtual RegExpNode* PropagateForward(NodeInfo* info);
virtual bool Emit(RegExpCompiler* compiler, GenerationVariant* variant);
+ virtual int EatsAtLeast(int recursion_depth);
+ virtual void GetQuickCheckDetails(QuickCheckDetails* details,
+ RegExpCompiler* compiler,
+ int characters_filled_in);
ZoneList<TextElement>* elements() { return elms_; }
void MakeCaseIndependent();
virtual int GreedyLoopTextLength();
void CalculateOffsets();
private:
+ enum TextEmitPassType {
+ NON_ASCII_MATCH,
+ CHARACTER_MATCH,
+ CASE_CHARACTER_MATCH,
+ CHARACTER_CLASS_MATCH
+ };
+ void TextEmitPass(RegExpCompiler* compiler,
+ TextEmitPassType pass,
+ bool preloaded,
+ GenerationVariant* variant,
+ bool first_element_checked,
+ int* checked_up_to);
+ int Length();
ZoneList<TextElement>* elms_;
};
int start_register() { return start_reg_; }
int end_register() { return end_reg_; }
virtual bool Emit(RegExpCompiler* compiler, GenerationVariant* variant);
+ virtual int EatsAtLeast(int recursion_depth) { return 0; }
+ virtual void GetQuickCheckDetails(QuickCheckDetails* details,
+ RegExpCompiler* compiler,
+ int characters_filled_in) {
+ return;
+ }
virtual RegExpNode* PropagateForward(NodeInfo* info);
virtual BackReferenceNode* Clone() { return new BackReferenceNode(*this); }
explicit EndNode(Action action) : action_(action) { }
virtual void Accept(NodeVisitor* visitor);
virtual bool Emit(RegExpCompiler* compiler, GenerationVariant* variant);
+ virtual int EatsAtLeast(int recursion_depth) { return 0; }
+ virtual void GetQuickCheckDetails(QuickCheckDetails* details,
+ RegExpCompiler* compiler,
+ int characters_filled_in) {
+ // Returning 0 from EatsAtLeast should ensure we never get here.
+ UNREACHABLE();
+ }
virtual RegExpNode* PropagateForward(NodeInfo* info);
virtual EndNode* Clone() { return new EndNode(*this); }
};
+class AlternativeGeneration;
+
+
class ChoiceNode: public RegExpNode {
public:
explicit ChoiceNode(int expected_size)
ZoneList<GuardedAlternative>* alternatives() { return alternatives_; }
DispatchTable* GetTable(bool ignore_case);
virtual bool Emit(RegExpCompiler* compiler, GenerationVariant* variant);
+ virtual int EatsAtLeast(int recursion_depth);
+ int EatsAtLeastHelper(int recursion_depth, RegExpNode* ignore_this_node);
+ virtual void GetQuickCheckDetails(QuickCheckDetails* details,
+ RegExpCompiler* compiler,
+ int characters_filled_in);
virtual RegExpNode* PropagateForward(NodeInfo* info);
virtual ChoiceNode* Clone() { return new ChoiceNode(*this); }
void GenerateGuard(RegExpMacroAssembler* macro_assembler,
Guard *guard,
GenerationVariant* variant);
+ int CalculatePreloadCharacters(RegExpCompiler* compiler);
+ bool EmitOutOfLineContinuation(RegExpCompiler* compiler,
+ GenerationVariant* variant,
+ GuardedAlternative alternative,
+ AlternativeGeneration* alt_gen,
+ int preload_characters,
+ bool next_expects_preload);
DispatchTable* table_;
bool being_calculated_;
};
class LoopChoiceNode: public ChoiceNode {
public:
- explicit LoopChoiceNode()
+ explicit LoopChoiceNode(bool body_can_be_zero_length)
: ChoiceNode(2),
loop_node_(NULL),
- continue_node_(NULL) { }
+ continue_node_(NULL),
+ body_can_be_zero_length_(body_can_be_zero_length) { }
void AddLoopAlternative(GuardedAlternative alt);
void AddContinueAlternative(GuardedAlternative alt);
virtual bool Emit(RegExpCompiler* compiler, GenerationVariant* variant);
+ virtual int EatsAtLeast(int recursion_depth); // Returns 0.
+ virtual void GetQuickCheckDetails(QuickCheckDetails* details,
+ RegExpCompiler* compiler,
+ int characters_filled_in);
virtual LoopChoiceNode* Clone() { return new LoopChoiceNode(*this); }
RegExpNode* loop_node() { return loop_node_; }
RegExpNode* continue_node() { return continue_node_; }
+ bool body_can_be_zero_length() { return body_can_be_zero_length_; }
virtual void Accept(NodeVisitor* visitor);
private:
RegExpNode* loop_node_;
RegExpNode* continue_node_;
+ bool body_can_be_zero_length_;
};
: DeferredAction(ActionNode::INCREMENT_REGISTER, reg) { }
};
- explicit GenerationVariant(Label* backtrack)
- : cp_offset_(0),
- actions_(NULL),
- backtrack_(backtrack),
- stop_node_(NULL),
- loop_label_(NULL) { }
GenerationVariant()
: cp_offset_(0),
actions_(NULL),
backtrack_(NULL),
stop_node_(NULL),
- loop_label_(NULL) { }
+ loop_label_(NULL),
+ characters_preloaded_(0) { }
bool Flush(RegExpCompiler* compiler, RegExpNode* successor);
int cp_offset() { return cp_offset_; }
DeferredAction* actions() { return actions_; }
bool is_trivial() {
- return backtrack_ == NULL && actions_ == NULL && cp_offset_ == 0;
+ return backtrack_ == NULL &&
+ actions_ == NULL &&
+ cp_offset_ == 0 &&
+ characters_preloaded_ == 0 &&
+ quick_check_performed_.characters() == 0;
}
Label* backtrack() { return backtrack_; }
Label* loop_label() { return loop_label_; }
RegExpNode* stop_node() { return stop_node_; }
- // These set methods should be used only on new GenerationVariants - the
- // intention is that GenerationVariants are immutable after creation.
+ int characters_preloaded() { return characters_preloaded_; }
+ QuickCheckDetails* quick_check_performed() { return &quick_check_performed_; }
+ bool mentions_reg(int reg);
+ // These set methods and AdvanceVariant should be used only on new
+ // GenerationVariants - the intention is that GenerationVariants are
+ // immutable after creation.
void add_action(DeferredAction* new_action) {
ASSERT(new_action->next_ == NULL);
new_action->next_ = actions_;
actions_ = new_action;
}
- void set_cp_offset(int new_cp_offset) {
- ASSERT(new_cp_offset >= cp_offset_);
- cp_offset_ = new_cp_offset;
- }
void set_backtrack(Label* backtrack) { backtrack_ = backtrack; }
void set_stop_node(RegExpNode* node) { stop_node_ = node; }
void set_loop_label(Label* label) { loop_label_ = label; }
- bool mentions_reg(int reg);
+ void set_characters_preloaded(int cpre) { characters_preloaded_ = cpre; }
+ void set_quick_check_performed(QuickCheckDetails* d) {
+ quick_check_performed_ = *d;
+ }
+ void clear_quick_check_performed() {
+ }
+ void AdvanceVariant(int by, bool ascii);
private:
int FindAffectedRegisters(OutSet* affected_registers);
void PerformDeferredActions(RegExpMacroAssembler* macro,
Label* backtrack_;
RegExpNode* stop_node_;
Label* loop_label_;
+ int characters_preloaded_;
+ QuickCheckDetails quick_check_performed_;
};
+
+
class NodeVisitor {
public:
virtual ~NodeVisitor() { }
projects / platform / upstream / v8.git / commitdiff