diff options
Diffstat (limited to 'js/src/irregexp/RegExpEngine.cpp')
| -rw-r--r-- | js/src/irregexp/RegExpEngine.cpp | 75 |
1 files changed, 43 insertions, 32 deletions
diff --git a/js/src/irregexp/RegExpEngine.cpp b/js/src/irregexp/RegExpEngine.cpp index 42787dc0f0..bf95b59dda 100644 --- a/js/src/irregexp/RegExpEngine.cpp +++ b/js/src/irregexp/RegExpEngine.cpp @@ -2010,8 +2010,9 @@ RegExpQuantifier::ToNode(int min, alternation->AddAlternative(GuardedAlternative(body->ToNode(compiler, answer))); } answer = alternation; - if (not_at_start && !compiler->read_backward()) + if (not_at_start && !compiler->read_backward()) { alternation->set_not_at_start(); + } } return answer; } @@ -2218,9 +2219,7 @@ RegExpCapture::ToNode(RegExpTree* body, int start_reg = RegExpCapture::StartRegister(index); int end_reg = RegExpCapture::EndRegister(index); if (compiler->read_backward()) { - // std::swap(start_reg, end_reg); - start_reg = RegExpCapture::EndRegister(index); - end_reg = RegExpCapture::StartRegister(index); + std::swap(start_reg, end_reg); } RegExpNode* store_end = ActionNode::StorePosition(end_reg, true, on_success); RegExpNode* body_node = body->ToNode(compiler, store_end); @@ -2604,6 +2603,7 @@ Trace::PerformDeferredActions(LifoAlloc* alloc, { // The "+1" is to avoid a push_limit of zero if stack_limit_slack() is 1. const int push_limit = (assembler->stack_limit_slack() + 1) / 2; + static const int kNoStore = INT32_MIN; // Count pushes performed to force a stack limit check occasionally. int pushes = 0; @@ -2620,7 +2620,7 @@ Trace::PerformDeferredActions(LifoAlloc* alloc, int value = 0; bool absolute = false; bool clear = false; - int store_position = -1; + int store_position = kNoStore; // This is a little tricky because we are scanning the actions in reverse // historical order (newest first). for (DeferredAction* action = actions_; @@ -2641,7 +2641,7 @@ Trace::PerformDeferredActions(LifoAlloc* alloc, // we can set undo_action to IGNORE if we know there is no value to // restore. undo_action = DEFER_RESTORE; - MOZ_ASSERT(store_position == -1); + MOZ_ASSERT(store_position == kNoStore); MOZ_ASSERT(!clear); break; } @@ -2649,14 +2649,14 @@ Trace::PerformDeferredActions(LifoAlloc* alloc, if (!absolute) { value++; } - MOZ_ASSERT(store_position == -1); + MOZ_ASSERT(store_position == kNoStore); MOZ_ASSERT(!clear); undo_action = DEFER_RESTORE; break; case ActionNode::STORE_POSITION: { Trace::DeferredCapture* pc = static_cast<Trace::DeferredCapture*>(action); - if (!clear && store_position == -1) { + if (!clear && store_position == kNoStore) { store_position = pc->cp_offset(); } @@ -2680,7 +2680,7 @@ Trace::PerformDeferredActions(LifoAlloc* alloc, // Since we're scanning in reverse order, if we've already // set the position we have to ignore historically earlier // clearing operations. - if (store_position == -1) { + if (store_position == kNoStore) { clear = true; } undo_action = DEFER_RESTORE; @@ -2710,7 +2710,7 @@ Trace::PerformDeferredActions(LifoAlloc* alloc, } // Perform the chronologically last action (or accumulated increment) // for the register. - if (store_position != -1) { + if (store_position != kNoStore) { assembler->WriteCurrentPositionToRegister(reg, store_position); } else if (clear) { assembler->ClearRegisters(reg, reg); @@ -2910,16 +2910,23 @@ EmitHat(RegExpCompiler* compiler, RegExpNode* on_success, Trace* trace) Trace new_trace(*trace); new_trace.InvalidateCurrentCharacter(); + // A positive (> 0) cp_offset means we've already successfully matched a + // non-empty-width part of the pattern, and thus cannot be at or before the + // start of the subject string. We can thus skip both at-start and + // bounds-checks when loading the one-character lookbehind. + const bool may_be_at_or_before_subject_string_start = new_trace.cp_offset() <= 0; + jit::Label ok; - if (new_trace.cp_offset() == 0) { - // The start of input counts as a newline in this context, so skip to - // ok if we are at the start. - assembler->CheckAtStart(&ok); + if (may_be_at_or_before_subject_string_start) { + // The start of input counts as a newline in this context, so skip to ok if + // we are at the start. + assembler->CheckAtStart(new_trace.cp_offset(), &ok); } - // We already checked that we are not at the start of input so it must be - // OK to load the previous character. - assembler->LoadCurrentCharacter(new_trace.cp_offset() -1, new_trace.backtrack(), false); + // If we've already checked that we are not at the start of input, it's okay + // to load the previous character without bounds checks. + const bool can_skip_bounds_check = !may_be_at_or_before_subject_string_start; + assembler->LoadCurrentCharacter(new_trace.cp_offset() -1, new_trace.backtrack(), can_skip_bounds_check); if (!assembler->CheckSpecialCharacterClass('n', new_trace.backtrack())) { // Newline means \n, \r, 0x2028 or 0x2029. @@ -2944,11 +2951,10 @@ EmitNotAfterLeadSurrogate(RegExpCompiler* compiler, RegExpNode* on_success, Trac new_trace.InvalidateCurrentCharacter(); jit::Label ok; - if (new_trace.cp_offset() == 0) - assembler->CheckAtStart(&ok); + if (new_trace.cp_offset() <= 0) { + assembler->CheckAtStart(new_trace.cp_offset(), &ok); + } - // We already checked that we are not at the start of input so it must be - // OK to load the previous character. assembler->LoadCurrentCharacter(new_trace.cp_offset() - 1, new_trace.backtrack(), false); assembler->CheckCharacterInRange(unicode::LeadSurrogateMin, unicode::LeadSurrogateMax, new_trace.backtrack()); @@ -2972,8 +2978,9 @@ EmitNotInSurrogatePair(RegExpCompiler* compiler, RegExpNode* on_success, Trace* Trace new_trace(*trace); new_trace.InvalidateCurrentCharacter(); - if (new_trace.cp_offset() == 0) - assembler->CheckAtStart(&ok); + if (new_trace.cp_offset() <= 0) { + assembler->CheckAtStart(new_trace.cp_offset(), &ok); + } // First check if next character is a trail surrogate. assembler->LoadCurrentCharacter(new_trace.cp_offset(), new_trace.backtrack(), false); @@ -3091,10 +3098,10 @@ AssertionNode::BacktrackIfPrevious(RegExpCompiler* compiler, jit::Label* non_word = backtrack_if_previous == kIsNonWord ? new_trace.backtrack() : &fall_through; jit::Label* word = backtrack_if_previous == kIsNonWord ? &fall_through : new_trace.backtrack(); - if (new_trace.cp_offset() == 0) { + if (new_trace.cp_offset() <= 0) { // The start of input counts as a non-word character, so the question is // decided if we are at the start. - assembler->CheckAtStart(non_word); + assembler->CheckAtStart(new_trace.cp_offset(), non_word); } // We already checked that we are not at the start of input so it must be // OK to load the previous character. @@ -4152,7 +4159,7 @@ ChoiceNode::CalculatePreloadCharacters(RegExpCompiler* compiler, int eats_at_lea RegExpNode* TextNode::GetSuccessorOfOmnivorousTextNode(RegExpCompiler* compiler) { - if (read_backward()) return NULL; + if (read_backward()) return nullptr; if (elements().length() != 1) return nullptr; @@ -4362,6 +4369,8 @@ ChoiceNode::Emit(RegExpCompiler* compiler, Trace* trace) // 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 (size_t i = first_normal_choice; i < choice_count; i++) { + bool is_last = i == choice_count - 1; + bool fall_through_on_failure = !is_last; GuardedAlternative alternative = alternatives()[i]; AlternativeGeneration* alt_gen = alt_gens.at(i); alt_gen->quick_check_details.set_characters(preload_characters); @@ -4377,20 +4386,20 @@ ChoiceNode::Emit(RegExpCompiler* compiler, Trace* trace) if (not_at_start_) new_trace.set_at_start(Trace::FALSE_VALUE); alt_gen->expects_preload = preload_is_current; bool generate_full_check_inline = false; - if (try_to_emit_quick_check_for_alternative(i) && + if (try_to_emit_quick_check_for_alternative(i == 0) && alternative.node()->EmitQuickCheck(compiler, &new_trace, preload_has_checked_bounds, &alt_gen->possible_success, &alt_gen->quick_check_details, - i < choice_count - 1)) { + fall_through_on_failure)) { // 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) { + if (!fall_through_on_failure) { macro_assembler->Bind(&alt_gen->possible_success); new_trace.set_quick_check_performed(&alt_gen->quick_check_details); new_trace.set_characters_preloaded(preload_characters); @@ -4398,7 +4407,7 @@ ChoiceNode::Emit(RegExpCompiler* compiler, Trace* trace) generate_full_check_inline = true; } } else if (alt_gen->quick_check_details.cannot_match()) { - if (i == choice_count - 1 && !greedy_loop) { + if (!fall_through_on_failure && !greedy_loop) { macro_assembler->JumpOrBacktrack(trace->backtrack()); } continue; @@ -4412,7 +4421,7 @@ ChoiceNode::Emit(RegExpCompiler* compiler, Trace* trace) alt_gen->expects_preload = false; new_trace.InvalidateCurrentCharacter(); } - if (i < choice_count - 1) { + if (!is_last) { new_trace.set_backtrack(&alt_gen->after); } generate_full_check_inline = true; @@ -4450,12 +4459,14 @@ ChoiceNode::Emit(RegExpCompiler* compiler, Trace* trace) if (new_trace.actions() != nullptr) { new_trace.set_flush_budget(new_flush_budget); } + bool next_expects_preload = + i == choice_count - 1 ? false : alt_gens.at(i + 1)->expects_preload; EmitOutOfLineContinuation(compiler, &new_trace, alternatives()[i], alt_gen, preload_characters, - alt_gens.at(i + 1)->expects_preload); + next_expects_preload); } } |