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/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*-
* vim: set ts=8 sts=2 et sw=2 tw=80:
* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
// Copyright 2020 the V8 project authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#include "irregexp/imported/regexp-macro-assembler-arch.h"
#include "irregexp/imported/regexp-stack.h"
#include "irregexp/imported/special-case.h"
#include "jit/Linker.h"
#include "jit/PerfSpewer.h"
#include "vm/MatchPairs.h"
#include "vm/Realm.h"
#ifdef MOZ_VTUNE
# include "vtune/VTuneWrapper.h"
#endif
#include "jit/ABIFunctionList-inl.h"
#include "jit/MacroAssembler-inl.h"
namespace v8 {
namespace internal {
using js::MatchPairs;
using js::jit::AbsoluteAddress;
using js::jit::Address;
using js::jit::AllocatableGeneralRegisterSet;
using js::jit::Assembler;
using js::jit::BaseIndex;
using js::jit::CodeLocationLabel;
using js::jit::GeneralRegisterBackwardIterator;
using js::jit::GeneralRegisterForwardIterator;
using js::jit::GeneralRegisterSet;
using js::jit::Imm32;
using js::jit::ImmPtr;
using js::jit::ImmWord;
using js::jit::JitCode;
using js::jit::Linker;
using js::jit::LiveGeneralRegisterSet;
using js::jit::Register;
using js::jit::Registers;
using js::jit::StackMacroAssembler;
SMRegExpMacroAssembler::SMRegExpMacroAssembler(JSContext* cx,
StackMacroAssembler& masm,
Zone* zone, Mode mode,
uint32_t num_capture_registers)
: NativeRegExpMacroAssembler(cx->isolate.ref(), zone),
cx_(cx),
masm_(masm),
mode_(mode),
num_registers_(num_capture_registers),
num_capture_registers_(num_capture_registers) {
// Each capture has a start and an end register
MOZ_ASSERT(num_capture_registers_ % 2 == 0);
AllocatableGeneralRegisterSet regs(GeneralRegisterSet::All());
input_end_pointer_ = regs.takeAny();
current_character_ = regs.takeAny();
current_position_ = regs.takeAny();
backtrack_stack_pointer_ = regs.takeAny();
temp0_ = regs.takeAny();
temp1_ = regs.takeAny();
if (!regs.empty()) {
// Not enough registers on x86.
temp2_ = regs.takeAny();
}
savedRegisters_ = js::jit::SavedNonVolatileRegisters(regs);
masm_.jump(&entry_label_); // We'll generate the entry code later
masm_.bind(&start_label_); // and continue from here.
}
int SMRegExpMacroAssembler::stack_limit_slack() {
return RegExpStack::kStackLimitSlack;
}
void SMRegExpMacroAssembler::AdvanceCurrentPosition(int by) {
if (by != 0) {
masm_.addPtr(Imm32(by * char_size()), current_position_);
}
}
void SMRegExpMacroAssembler::AdvanceRegister(int reg, int by) {
MOZ_ASSERT(reg >= 0 && reg < num_registers_);
if (by != 0) {
masm_.addPtr(Imm32(by), register_location(reg));
}
}
void SMRegExpMacroAssembler::Backtrack() {
#ifdef DEBUG
js::jit::Label bailOut;
// Check for simulating interrupt
masm_.branch32(Assembler::NotEqual,
AbsoluteAddress(&cx_->isolate->shouldSimulateInterrupt_),
Imm32(0), &bailOut);
#endif
// Check for an interrupt. We have to restart from the beginning if we
// are interrupted, so we only check for urgent interrupts.
js::jit::Label noInterrupt;
masm_.branchTest32(
Assembler::Zero, AbsoluteAddress(cx_->addressOfInterruptBits()),
Imm32(uint32_t(js::InterruptReason::CallbackUrgent)), &noInterrupt);
#ifdef DEBUG
// bailing out if we have simulating interrupt flag set
masm_.bind(&bailOut);
#endif
masm_.movePtr(ImmWord(int32_t(js::RegExpRunStatus::Error)), temp0_);
masm_.jump(&exit_label_);
masm_.bind(&noInterrupt);
// Pop code location from backtrack stack and jump to location.
Pop(temp0_);
masm_.jump(temp0_);
}
void SMRegExpMacroAssembler::Bind(Label* label) {
masm_.bind(label->inner());
if (label->patchOffset_.bound()) {
AddLabelPatch(label->patchOffset_, label->pos());
}
}
// Check if current_position + cp_offset is the input start
void SMRegExpMacroAssembler::CheckAtStartImpl(int cp_offset, Label* on_cond,
Assembler::Condition cond) {
Address addr(current_position_, cp_offset * char_size());
masm_.computeEffectiveAddress(addr, temp0_);
masm_.branchPtr(cond, inputStart(), temp0_, LabelOrBacktrack(on_cond));
}
void SMRegExpMacroAssembler::CheckAtStart(int cp_offset, Label* on_at_start) {
CheckAtStartImpl(cp_offset, on_at_start, Assembler::Equal);
}
void SMRegExpMacroAssembler::CheckNotAtStart(int cp_offset,
Label* on_not_at_start) {
CheckAtStartImpl(cp_offset, on_not_at_start, Assembler::NotEqual);
}
void SMRegExpMacroAssembler::CheckCharacterImpl(Imm32 c, Label* on_cond,
Assembler::Condition cond) {
masm_.branch32(cond, current_character_, c, LabelOrBacktrack(on_cond));
}
void SMRegExpMacroAssembler::CheckCharacter(uint32_t c, Label* on_equal) {
CheckCharacterImpl(Imm32(c), on_equal, Assembler::Equal);
}
void SMRegExpMacroAssembler::CheckNotCharacter(uint32_t c,
Label* on_not_equal) {
CheckCharacterImpl(Imm32(c), on_not_equal, Assembler::NotEqual);
}
void SMRegExpMacroAssembler::CheckCharacterGT(base::uc16 limit,
Label* on_greater) {
CheckCharacterImpl(Imm32(limit), on_greater, Assembler::GreaterThan);
}
void SMRegExpMacroAssembler::CheckCharacterLT(base::uc16 limit,
Label* on_less) {
CheckCharacterImpl(Imm32(limit), on_less, Assembler::LessThan);
}
// Bitwise-and the current character with mask and then check for a
// match with c.
void SMRegExpMacroAssembler::CheckCharacterAfterAndImpl(uint32_t c,
uint32_t mask,
Label* on_cond,
bool is_not) {
if (c == 0) {
Assembler::Condition cond = is_not ? Assembler::NonZero : Assembler::Zero;
masm_.branchTest32(cond, current_character_, Imm32(mask),
LabelOrBacktrack(on_cond));
} else {
Assembler::Condition cond = is_not ? Assembler::NotEqual : Assembler::Equal;
masm_.move32(Imm32(mask), temp0_);
masm_.and32(current_character_, temp0_);
masm_.branch32(cond, temp0_, Imm32(c), LabelOrBacktrack(on_cond));
}
}
void SMRegExpMacroAssembler::CheckCharacterAfterAnd(uint32_t c, uint32_t mask,
Label* on_equal) {
CheckCharacterAfterAndImpl(c, mask, on_equal, /*is_not =*/false);
}
void SMRegExpMacroAssembler::CheckNotCharacterAfterAnd(uint32_t c,
uint32_t mask,
Label* on_not_equal) {
CheckCharacterAfterAndImpl(c, mask, on_not_equal, /*is_not =*/true);
}
// Subtract minus from the current character, then bitwise-and the
// result with mask, then check for a match with c.
void SMRegExpMacroAssembler::CheckNotCharacterAfterMinusAnd(
base::uc16 c, base::uc16 minus, base::uc16 mask, Label* on_not_equal) {
masm_.computeEffectiveAddress(Address(current_character_, -minus), temp0_);
if (c == 0) {
masm_.branchTest32(Assembler::NonZero, temp0_, Imm32(mask),
LabelOrBacktrack(on_not_equal));
} else {
masm_.and32(Imm32(mask), temp0_);
masm_.branch32(Assembler::NotEqual, temp0_, Imm32(c),
LabelOrBacktrack(on_not_equal));
}
}
// If the current position matches the position stored on top of the backtrack
// stack, pops the backtrack stack and branches to the given label.
void SMRegExpMacroAssembler::CheckGreedyLoop(Label* on_equal) {
js::jit::Label fallthrough;
masm_.branchPtr(Assembler::NotEqual, Address(backtrack_stack_pointer_, 0),
current_position_, &fallthrough);
masm_.addPtr(Imm32(sizeof(void*)), backtrack_stack_pointer_); // Pop.
JumpOrBacktrack(on_equal);
masm_.bind(&fallthrough);
}
void SMRegExpMacroAssembler::CheckCharacterInRangeImpl(
base::uc16 from, base::uc16 to, Label* on_cond, Assembler::Condition cond) {
// x is in [from,to] if unsigned(x - from) <= to - from
masm_.computeEffectiveAddress(Address(current_character_, -from), temp0_);
masm_.branch32(cond, temp0_, Imm32(to - from), LabelOrBacktrack(on_cond));
}
void SMRegExpMacroAssembler::CheckCharacterInRange(base::uc16 from,
base::uc16 to,
Label* on_in_range) {
CheckCharacterInRangeImpl(from, to, on_in_range, Assembler::BelowOrEqual);
}
void SMRegExpMacroAssembler::CheckCharacterNotInRange(base::uc16 from,
base::uc16 to,
Label* on_not_in_range) {
CheckCharacterInRangeImpl(from, to, on_not_in_range, Assembler::Above);
}
/* static */
bool SMRegExpMacroAssembler::IsCharacterInRangeArray(uint32_t c,
ByteArrayData* ranges) {
js::AutoUnsafeCallWithABI unsafe;
MOZ_ASSERT(ranges->length() % sizeof(uint16_t) == 0);
uint32_t length = ranges->length() / sizeof(uint16_t);
MOZ_ASSERT(length > 0);
// Fast paths.
if (c < ranges->getTyped<uint16_t>(0)) {
// |c| is lower than the start of the first range.
// It is not in the range array.
return false;
}
if (c >= ranges->getTyped<uint16_t>(length - 1)) {
// |c| is higher than the last entry. If the table contains an odd
// number of entries, the last range is open-ended, so |c| is in
// the range array iff |length| is odd.
return (length % 2) != 0;
}
// |ranges| is stored as an interval list: an ordered list of
// starting points, where every even index marks the beginning of a
// range of characters that are included, and every odd index marks
// the beginning of a range of characters that are excluded. For
// example, the set [1,2,3,7,8,9] would be represented as the
// range array [1,4,7,10]. If |ranges| has an odd number of entries,
// the last included range is open-ended (so the set containing
// every character would be represented as [0]).
//
// Because of the symmetry between included and excluded ranges, we
// can do a binary search for the index in |ranges| with the value
// closest to but not exceeding |c|. If that index is even, |c| is
// in an included range. If that index is odd, |c| is in an excluded
// range.
uint32_t lower = 0;
uint32_t upper = length;
uint32_t mid = 0;
do {
mid = lower + (upper - lower) / 2;
const base::uc16 elem = ranges->getTyped<uint16_t>(mid);
if (c < elem) {
upper = mid;
} else if (c > elem) {
lower = mid + 1;
} else {
break;
}
} while (lower < upper);
uint32_t rangeIndex = c < ranges->getTyped<uint16_t>(mid) ? mid - 1 : mid;
// Included ranges start at even indices and end at odd indices.
return rangeIndex % 2 == 0;
}
void SMRegExpMacroAssembler::CallIsCharacterInRangeArray(
const ZoneList<CharacterRange>* ranges) {
Handle<ByteArray> rangeArray = GetOrAddRangeArray(ranges);
masm_.movePtr(ImmPtr(rangeArray->inner()), temp0_);
// Save volatile regs. Temp regs don't need to be saved.
LiveGeneralRegisterSet volatileRegs(GeneralRegisterSet::Volatile());
volatileRegs.takeUnchecked(temp0_);
volatileRegs.takeUnchecked(temp1_);
if (temp2_ != js::jit::InvalidReg) {
volatileRegs.takeUnchecked(temp2_);
}
masm_.PushRegsInMask(volatileRegs);
using Fn = bool (*)(uint32_t, ByteArrayData*);
masm_.setupUnalignedABICall(temp1_);
masm_.passABIArg(current_character_);
masm_.passABIArg(temp0_);
masm_.callWithABI<Fn, ::js::irregexp::IsCharacterInRangeArray>();
masm_.storeCallBoolResult(temp1_);
masm_.PopRegsInMask(volatileRegs);
// GetOrAddRangeArray caches previously seen range arrays to reduce
// memory usage, so this may not be the first time we've seen this
// range array. We only need to transfer ownership from the
// HandleScope to the |tables_| vector once.
PseudoHandle<ByteArrayData> rawRangeArray =
rangeArray->maybeTakeOwnership(isolate());
if (rawRangeArray) {
AddTable(std::move(rawRangeArray));
}
}
bool SMRegExpMacroAssembler::CheckCharacterInRangeArray(
const ZoneList<CharacterRange>* ranges, Label* on_in_range) {
CallIsCharacterInRangeArray(ranges);
masm_.branchTest32(Assembler::NonZero, temp1_, temp1_,
LabelOrBacktrack(on_in_range));
return true;
}
bool SMRegExpMacroAssembler::CheckCharacterNotInRangeArray(
const ZoneList<CharacterRange>* ranges, Label* on_not_in_range) {
CallIsCharacterInRangeArray(ranges);
masm_.branchTest32(Assembler::Zero, temp1_, temp1_,
LabelOrBacktrack(on_not_in_range));
return true;
}
void SMRegExpMacroAssembler::CheckBitInTable(Handle<ByteArray> table,
Label* on_bit_set) {
// Claim ownership of the ByteArray from the current HandleScope.
// ByteArrays are allocated on the C++ heap and are (eventually)
// owned by the RegExpShared.
PseudoHandle<ByteArrayData> rawTable = table->takeOwnership(isolate());
masm_.movePtr(ImmPtr(rawTable->data()), temp0_);
masm_.move32(Imm32(kTableMask), temp1_);
masm_.and32(current_character_, temp1_);
masm_.load8ZeroExtend(BaseIndex(temp0_, temp1_, js::jit::TimesOne), temp0_);
masm_.branchTest32(Assembler::NonZero, temp0_, temp0_,
LabelOrBacktrack(on_bit_set));
// Transfer ownership of |rawTable| to the |tables_| vector.
AddTable(std::move(rawTable));
}
void SMRegExpMacroAssembler::CheckNotBackReferenceImpl(int start_reg,
bool read_backward,
bool unicode,
Label* on_no_match,
bool ignore_case) {
js::jit::Label fallthrough;
// Captures are stored as a sequential pair of registers.
// Find the length of the back-referenced capture and load the
// capture's start index into current_character_.
masm_.loadPtr(register_location(start_reg), // index of start
current_character_);
masm_.loadPtr(register_location(start_reg + 1), temp0_); // index of end
masm_.subPtr(current_character_, temp0_); // length of capture
// Capture registers are either both set or both cleared.
// If the capture length is zero, then the capture is either empty or cleared.
// Fall through in both cases.
masm_.branchPtr(Assembler::Equal, temp0_, ImmWord(0), &fallthrough);
// Check that there are sufficient characters left in the input.
if (read_backward) {
// If start + len > current, there isn't enough room for a
// lookbehind backreference.
masm_.loadPtr(inputStart(), temp1_);
masm_.addPtr(temp0_, temp1_);
masm_.branchPtr(Assembler::GreaterThan, temp1_, current_position_,
LabelOrBacktrack(on_no_match));
} else {
// current_position_ is the negative offset from the end.
// If current + len > 0, there isn't enough room for a backreference.
masm_.movePtr(current_position_, temp1_);
masm_.addPtr(temp0_, temp1_);
masm_.branchPtr(Assembler::GreaterThan, temp1_, ImmWord(0),
LabelOrBacktrack(on_no_match));
}
if (mode_ == UC16 && ignore_case) {
// We call a helper function for case-insensitive non-latin1 strings.
// Save volatile regs. temp1_, temp2_, and current_character_
// don't need to be saved. current_position_ needs to be saved
// even if it's non-volatile, because we modify it to use as an argument.
LiveGeneralRegisterSet volatileRegs(GeneralRegisterSet::Volatile());
volatileRegs.addUnchecked(current_position_);
volatileRegs.takeUnchecked(temp1_);
if (temp2_ != js::jit::InvalidReg) {
volatileRegs.takeUnchecked(temp2_);
}
volatileRegs.takeUnchecked(current_character_);
masm_.PushRegsInMask(volatileRegs);
// Parameters are
// Address captured - Address of captured substring's start.
// Address current - Address of current character position.
// size_t byte_length - length of capture (in bytes)
// Compute |captured|
masm_.addPtr(input_end_pointer_, current_character_);
// Compute |current|
masm_.addPtr(input_end_pointer_, current_position_);
if (read_backward) {
// Offset by length when matching backwards.
masm_.subPtr(temp0_, current_position_);
}
using Fn = uint32_t (*)(const char16_t*, const char16_t*, size_t);
masm_.setupUnalignedABICall(temp1_);
masm_.passABIArg(current_character_);
masm_.passABIArg(current_position_);
masm_.passABIArg(temp0_);
if (unicode) {
masm_.callWithABI<Fn, ::js::irregexp::CaseInsensitiveCompareUnicode>();
} else {
masm_.callWithABI<Fn, ::js::irregexp::CaseInsensitiveCompareNonUnicode>();
}
masm_.storeCallInt32Result(temp1_);
masm_.PopRegsInMask(volatileRegs);
masm_.branchTest32(Assembler::Zero, temp1_, temp1_,
LabelOrBacktrack(on_no_match));
// On success, advance position by length of capture
if (read_backward) {
masm_.subPtr(temp0_, current_position_);
} else {
masm_.addPtr(temp0_, current_position_);
}
masm_.bind(&fallthrough);
return;
}
// We will be modifying current_position_. Save it in case the match fails.
masm_.push(current_position_);
// Compute start of capture string
masm_.addPtr(input_end_pointer_, current_character_);
// Compute start of match string
masm_.addPtr(input_end_pointer_, current_position_);
if (read_backward) {
// Offset by length when matching backwards.
masm_.subPtr(temp0_, current_position_);
}
// Compute end of match string
masm_.addPtr(current_position_, temp0_);
Register nextCaptureChar = temp1_;
Register nextMatchChar = temp2_;
if (temp2_ == js::jit::InvalidReg) {
masm_.push(backtrack_stack_pointer_);
nextMatchChar = backtrack_stack_pointer_;
}
js::jit::Label success;
js::jit::Label fail;
js::jit::Label loop;
masm_.bind(&loop);
// Load next character from each string.
if (mode_ == LATIN1) {
masm_.load8ZeroExtend(Address(current_character_, 0), nextCaptureChar);
masm_.load8ZeroExtend(Address(current_position_, 0), nextMatchChar);
} else {
masm_.load16ZeroExtend(Address(current_character_, 0), nextCaptureChar);
masm_.load16ZeroExtend(Address(current_position_, 0), nextMatchChar);
}
if (ignore_case) {
MOZ_ASSERT(mode_ == LATIN1);
// Try exact match.
js::jit::Label loop_increment;
masm_.branch32(Assembler::Equal, nextCaptureChar, nextMatchChar,
&loop_increment);
// Mismatch. Try case-insensitive match.
// Force the capture character to lower case (by setting bit 0x20)
// then check to see if it is a letter.
js::jit::Label convert_match;
masm_.or32(Imm32(0x20), nextCaptureChar);
// Check if it is in [a,z].
masm_.computeEffectiveAddress(Address(nextCaptureChar, -'a'),
nextMatchChar);
masm_.branch32(Assembler::BelowOrEqual, nextMatchChar, Imm32('z' - 'a'),
&convert_match);
// Check for values in range [224,254].
// Exclude 247 (U+00F7 DIVISION SIGN).
masm_.sub32(Imm32(224 - 'a'), nextMatchChar);
masm_.branch32(Assembler::Above, nextMatchChar, Imm32(254 - 224), &fail);
masm_.branch32(Assembler::Equal, nextMatchChar, Imm32(247 - 224), &fail);
// Capture character is lower case. Convert match character
// to lower case and compare.
masm_.bind(&convert_match);
masm_.load8ZeroExtend(Address(current_position_, 0), nextMatchChar);
masm_.or32(Imm32(0x20), nextMatchChar);
masm_.branch32(Assembler::NotEqual, nextCaptureChar, nextMatchChar, &fail);
masm_.bind(&loop_increment);
} else {
// Fail if characters do not match.
masm_.branch32(Assembler::NotEqual, nextCaptureChar, nextMatchChar, &fail);
}
// Increment pointers into match and capture strings.
masm_.addPtr(Imm32(char_size()), current_character_);
masm_.addPtr(Imm32(char_size()), current_position_);
// Loop if we have not reached the end of the match string.
masm_.branchPtr(Assembler::Below, current_position_, temp0_, &loop);
masm_.jump(&success);
// If we fail, restore current_position_ and branch.
masm_.bind(&fail);
if (temp2_ == js::jit::InvalidReg) {
// Restore backtrack_stack_pointer_ when it was used as a temp register.
masm_.pop(backtrack_stack_pointer_);
}
masm_.pop(current_position_);
JumpOrBacktrack(on_no_match);
masm_.bind(&success);
if (temp2_ == js::jit::InvalidReg) {
// Restore backtrack_stack_pointer_ when it was used as a temp register.
masm_.pop(backtrack_stack_pointer_);
}
// Drop saved value of current_position_
masm_.addToStackPtr(Imm32(sizeof(uintptr_t)));
// current_position_ is a pointer. Convert it back to an offset.
masm_.subPtr(input_end_pointer_, current_position_);
if (read_backward) {
// Subtract match length if we matched backward
masm_.addPtr(register_location(start_reg), current_position_);
masm_.subPtr(register_location(start_reg + 1), current_position_);
}
masm_.bind(&fallthrough);
}
// Branch if a back-reference does not match a previous capture.
void SMRegExpMacroAssembler::CheckNotBackReference(int start_reg,
bool read_backward,
Label* on_no_match) {
CheckNotBackReferenceImpl(start_reg, read_backward, /*unicode = */ false,
on_no_match, /*ignore_case = */ false);
}
void SMRegExpMacroAssembler::CheckNotBackReferenceIgnoreCase(
int start_reg, bool read_backward, bool unicode, Label* on_no_match) {
CheckNotBackReferenceImpl(start_reg, read_backward, unicode, on_no_match,
/*ignore_case = */ true);
}
// Checks whether the given offset from the current position is
// inside the input string.
void SMRegExpMacroAssembler::CheckPosition(int cp_offset,
Label* on_outside_input) {
// Note: current_position_ is a (negative) byte offset relative to
// the end of the input string.
if (cp_offset >= 0) {
// end + current + offset >= end
// <=> current + offset >= 0
// <=> current >= -offset
masm_.branchPtr(Assembler::GreaterThanOrEqual, current_position_,
ImmWord(-cp_offset * char_size()),
LabelOrBacktrack(on_outside_input));
} else {
// Compute offset position
masm_.computeEffectiveAddress(
Address(current_position_, cp_offset * char_size()), temp0_);
// Compare to start of input.
masm_.branchPtr(Assembler::GreaterThan, inputStart(), temp0_,
LabelOrBacktrack(on_outside_input));
}
}
// This function attempts to generate special case code for character classes.
// Returns true if a special case is generated.
// Otherwise returns false and generates no code.
bool SMRegExpMacroAssembler::CheckSpecialCharacterClass(
StandardCharacterSet type, Label* on_no_match) {
js::jit::Label* no_match = LabelOrBacktrack(on_no_match);
// Note: throughout this function, range checks (c in [min, max])
// are implemented by an unsigned (c - min) <= (max - min) check.
switch (type) {
case StandardCharacterSet::kWhitespace: {
// Match space-characters
if (mode_ != LATIN1) {
return false;
}
js::jit::Label success;
// One byte space characters are ' ', '\t'..'\r', and '\u00a0' (NBSP).
// Check ' '
masm_.branch32(Assembler::Equal, current_character_, Imm32(' '),
&success);
// Check '\t'..'\r'
masm_.computeEffectiveAddress(Address(current_character_, -'\t'), temp0_);
masm_.branch32(Assembler::BelowOrEqual, temp0_, Imm32('\r' - '\t'),
&success);
// Check \u00a0.
masm_.branch32(Assembler::NotEqual, temp0_, Imm32(0x00a0 - '\t'),
no_match);
masm_.bind(&success);
return true;
}
case StandardCharacterSet::kNotWhitespace:
// The emitted code for generic character classes is good enough.
return false;
case StandardCharacterSet::kDigit:
// Match latin1 digits ('0'-'9')
masm_.computeEffectiveAddress(Address(current_character_, -'0'), temp0_);
masm_.branch32(Assembler::Above, temp0_, Imm32('9' - '0'), no_match);
return true;
case StandardCharacterSet::kNotDigit:
// Match anything except latin1 digits ('0'-'9')
masm_.computeEffectiveAddress(Address(current_character_, -'0'), temp0_);
masm_.branch32(Assembler::BelowOrEqual, temp0_, Imm32('9' - '0'),
no_match);
return true;
case StandardCharacterSet::kNotLineTerminator:
// Match non-newlines. This excludes '\n' (0x0a), '\r' (0x0d),
// U+2028 LINE SEPARATOR, and U+2029 PARAGRAPH SEPARATOR.
// To test for 0x0a and 0x0d efficiently, we XOR the input with 1.
// This converts 0x0a to 0x0b, and 0x0d to 0x0c, allowing us to
// test for the contiguous range 0x0b..0x0c.
masm_.move32(current_character_, temp0_);
masm_.xor32(Imm32(0x01), temp0_);
masm_.sub32(Imm32(0x0b), temp0_);
masm_.branch32(Assembler::BelowOrEqual, temp0_, Imm32(0x0c - 0x0b),
no_match);
if (mode_ == UC16) {
// Compare original value to 0x2028 and 0x2029, using the already
// computed (current_char ^ 0x01 - 0x0b). I.e., check for
// 0x201d (0x2028 - 0x0b) or 0x201e.
masm_.sub32(Imm32(0x2028 - 0x0b), temp0_);
masm_.branch32(Assembler::BelowOrEqual, temp0_, Imm32(0x2029 - 0x2028),
no_match);
}
return true;
case StandardCharacterSet::kWord:
// \w matches the set of 63 characters defined in Runtime Semantics:
// WordCharacters. We use a static lookup table, which is defined in
// regexp-macro-assembler.cc.
// Note: if both Unicode and IgnoreCase are true, \w matches a
// larger set of characters. That case is handled elsewhere.
if (mode_ != LATIN1) {
masm_.branch32(Assembler::Above, current_character_, Imm32('z'),
no_match);
}
static_assert(arraysize(word_character_map) > unibrow::Latin1::kMaxChar);
masm_.movePtr(ImmPtr(word_character_map), temp0_);
masm_.load8ZeroExtend(
BaseIndex(temp0_, current_character_, js::jit::TimesOne), temp0_);
masm_.branchTest32(Assembler::Zero, temp0_, temp0_, no_match);
return true;
case StandardCharacterSet::kNotWord: {
// See 'w' above.
js::jit::Label done;
if (mode_ != LATIN1) {
masm_.branch32(Assembler::Above, current_character_, Imm32('z'), &done);
}
static_assert(arraysize(word_character_map) > unibrow::Latin1::kMaxChar);
masm_.movePtr(ImmPtr(word_character_map), temp0_);
masm_.load8ZeroExtend(
BaseIndex(temp0_, current_character_, js::jit::TimesOne), temp0_);
masm_.branchTest32(Assembler::NonZero, temp0_, temp0_, no_match);
if (mode_ != LATIN1) {
masm_.bind(&done);
}
return true;
}
////////////////////////////////////////////////////////////////////////
// Non-standard classes (with no syntactic shorthand) used internally //
////////////////////////////////////////////////////////////////////////
case StandardCharacterSet::kEverything:
// Match any character
return true;
case StandardCharacterSet::kLineTerminator:
// Match newlines. The opposite of '.'. See '.' above.
masm_.move32(current_character_, temp0_);
masm_.xor32(Imm32(0x01), temp0_);
masm_.sub32(Imm32(0x0b), temp0_);
if (mode_ == LATIN1) {
masm_.branch32(Assembler::Above, temp0_, Imm32(0x0c - 0x0b), no_match);
} else {
MOZ_ASSERT(mode_ == UC16);
js::jit::Label done;
masm_.branch32(Assembler::BelowOrEqual, temp0_, Imm32(0x0c - 0x0b),
&done);
// Compare original value to 0x2028 and 0x2029, using the already
// computed (current_char ^ 0x01 - 0x0b). I.e., check for
// 0x201d (0x2028 - 0x0b) or 0x201e.
masm_.sub32(Imm32(0x2028 - 0x0b), temp0_);
masm_.branch32(Assembler::Above, temp0_, Imm32(0x2029 - 0x2028),
no_match);
masm_.bind(&done);
}
return true;
}
return false;
}
void SMRegExpMacroAssembler::Fail() {
masm_.movePtr(ImmWord(int32_t(js::RegExpRunStatus::Success_NotFound)),
temp0_);
masm_.jump(&exit_label_);
}
void SMRegExpMacroAssembler::GoTo(Label* to) {
masm_.jump(LabelOrBacktrack(to));
}
void SMRegExpMacroAssembler::IfRegisterGE(int reg, int comparand,
Label* if_ge) {
masm_.branchPtr(Assembler::GreaterThanOrEqual, register_location(reg),
ImmWord(comparand), LabelOrBacktrack(if_ge));
}
void SMRegExpMacroAssembler::IfRegisterLT(int reg, int comparand,
Label* if_lt) {
masm_.branchPtr(Assembler::LessThan, register_location(reg),
ImmWord(comparand), LabelOrBacktrack(if_lt));
}
void SMRegExpMacroAssembler::IfRegisterEqPos(int reg, Label* if_eq) {
masm_.branchPtr(Assembler::Equal, register_location(reg), current_position_,
LabelOrBacktrack(if_eq));
}
// This is a word-for-word identical copy of the V8 code, which is
// duplicated in at least nine different places in V8 (one per
// supported architecture) with no differences outside of comments and
// formatting. It should be hoisted into the superclass. Once that is
// done upstream, this version can be deleted.
void SMRegExpMacroAssembler::LoadCurrentCharacterImpl(int cp_offset,
Label* on_end_of_input,
bool check_bounds,
int characters,
int eats_at_least) {
// It's possible to preload a small number of characters when each success
// path requires a large number of characters, but not the reverse.
MOZ_ASSERT(eats_at_least >= characters);
MOZ_ASSERT(cp_offset < (1 << 30)); // Be sane! (And ensure negation works)
if (check_bounds) {
if (cp_offset >= 0) {
CheckPosition(cp_offset + eats_at_least - 1, on_end_of_input);
} else {
CheckPosition(cp_offset, on_end_of_input);
}
}
LoadCurrentCharacterUnchecked(cp_offset, characters);
}
// Load the character (or characters) at the specified offset from the
// current position. Zero-extend to 32 bits.
void SMRegExpMacroAssembler::LoadCurrentCharacterUnchecked(int cp_offset,
int characters) {
BaseIndex address(input_end_pointer_, current_position_, js::jit::TimesOne,
cp_offset * char_size());
if (mode_ == LATIN1) {
if (characters == 4) {
masm_.load32(address, current_character_);
} else if (characters == 2) {
masm_.load16ZeroExtend(address, current_character_);
} else {
MOZ_ASSERT(characters == 1);
masm_.load8ZeroExtend(address, current_character_);
}
} else {
MOZ_ASSERT(mode_ == UC16);
if (characters == 2) {
masm_.load32(address, current_character_);
} else {
MOZ_ASSERT(characters == 1);
masm_.load16ZeroExtend(address, current_character_);
}
}
}
void SMRegExpMacroAssembler::PopCurrentPosition() { Pop(current_position_); }
void SMRegExpMacroAssembler::PopRegister(int register_index) {
Pop(temp0_);
masm_.storePtr(temp0_, register_location(register_index));
}
void SMRegExpMacroAssembler::PushBacktrack(Label* label) {
MOZ_ASSERT(!label->is_bound());
MOZ_ASSERT(!label->patchOffset_.bound());
label->patchOffset_ = masm_.movWithPatch(ImmPtr(nullptr), temp0_);
MOZ_ASSERT(label->patchOffset_.bound());
Push(temp0_);
CheckBacktrackStackLimit();
}
void SMRegExpMacroAssembler::PushCurrentPosition() { Push(current_position_); }
void SMRegExpMacroAssembler::PushRegister(int register_index,
StackCheckFlag check_stack_limit) {
masm_.loadPtr(register_location(register_index), temp0_);
Push(temp0_);
if (check_stack_limit) {
CheckBacktrackStackLimit();
}
}
void SMRegExpMacroAssembler::ReadCurrentPositionFromRegister(int reg) {
masm_.loadPtr(register_location(reg), current_position_);
}
void SMRegExpMacroAssembler::WriteCurrentPositionToRegister(int reg,
int cp_offset) {
if (cp_offset == 0) {
masm_.storePtr(current_position_, register_location(reg));
} else {
Address addr(current_position_, cp_offset * char_size());
masm_.computeEffectiveAddress(addr, temp0_);
masm_.storePtr(temp0_, register_location(reg));
}
}
// Note: The backtrack stack pointer is stored in a register as an
// offset from the stack top, not as a bare pointer, so that it is not
// corrupted if the backtrack stack grows (and therefore moves).
void SMRegExpMacroAssembler::ReadStackPointerFromRegister(int reg) {
masm_.loadPtr(register_location(reg), backtrack_stack_pointer_);
masm_.addPtr(backtrackStackBase(), backtrack_stack_pointer_);
}
void SMRegExpMacroAssembler::WriteStackPointerToRegister(int reg) {
masm_.movePtr(backtrack_stack_pointer_, temp0_);
masm_.subPtr(backtrackStackBase(), temp0_);
masm_.storePtr(temp0_, register_location(reg));
}
// When matching a regexp that is anchored at the end, this operation
// is used to try skipping the beginning of long strings. If the
// maximum length of a match is less than the length of the string, we
// can skip the initial len - max_len bytes.
void SMRegExpMacroAssembler::SetCurrentPositionFromEnd(int by) {
js::jit::Label after_position;
masm_.branchPtr(Assembler::GreaterThanOrEqual, current_position_,
ImmWord(-by * char_size()), &after_position);
masm_.movePtr(ImmWord(-by * char_size()), current_position_);
// On RegExp code entry (where this operation is used), the character before
// the current position is expected to be already loaded.
// We have advanced the position, so it's safe to read backwards.
LoadCurrentCharacterUnchecked(-1, 1);
masm_.bind(&after_position);
}
void SMRegExpMacroAssembler::SetRegister(int register_index, int to) {
MOZ_ASSERT(register_index >= num_capture_registers_);
masm_.storePtr(ImmWord(to), register_location(register_index));
}
// Returns true if a regexp match can be restarted (aka the regexp is global).
// The return value is not used anywhere, but we implement it to be safe.
bool SMRegExpMacroAssembler::Succeed() {
masm_.jump(&success_label_);
return global();
}
// Capture registers are initialized to input[-1]
void SMRegExpMacroAssembler::ClearRegisters(int reg_from, int reg_to) {
MOZ_ASSERT(reg_from <= reg_to);
masm_.loadPtr(inputStart(), temp0_);
masm_.subPtr(Imm32(char_size()), temp0_);
for (int reg = reg_from; reg <= reg_to; reg++) {
masm_.storePtr(temp0_, register_location(reg));
}
}
void SMRegExpMacroAssembler::Push(Register source) {
MOZ_ASSERT(source != backtrack_stack_pointer_);
masm_.subPtr(Imm32(sizeof(void*)), backtrack_stack_pointer_);
masm_.storePtr(source, Address(backtrack_stack_pointer_, 0));
}
void SMRegExpMacroAssembler::Pop(Register target) {
MOZ_ASSERT(target != backtrack_stack_pointer_);
masm_.loadPtr(Address(backtrack_stack_pointer_, 0), target);
masm_.addPtr(Imm32(sizeof(void*)), backtrack_stack_pointer_);
}
void SMRegExpMacroAssembler::JumpOrBacktrack(Label* to) {
if (to) {
masm_.jump(to->inner());
} else {
Backtrack();
}
}
// Generate a quick inline test for backtrack stack overflow.
// If the test fails, call an OOL handler to try growing the stack.
void SMRegExpMacroAssembler::CheckBacktrackStackLimit() {
js::jit::Label no_stack_overflow;
masm_.branchPtr(
Assembler::BelowOrEqual,
AbsoluteAddress(isolate()->regexp_stack()->limit_address_address()),
backtrack_stack_pointer_, &no_stack_overflow);
masm_.call(&stack_overflow_label_);
// Exit with an exception if the call failed
masm_.branchTest32(Assembler::Zero, temp0_, temp0_,
&exit_with_exception_label_);
masm_.bind(&no_stack_overflow);
}
// This is used to sneak an OOM through the V8 layer.
static Handle<HeapObject> DummyCode() {
return Handle<HeapObject>::fromHandleValue(JS::UndefinedHandleValue);
}
// Finalize code. This is called last, so that we know how many
// registers we need.
Handle<HeapObject> SMRegExpMacroAssembler::GetCode(Handle<String> source) {
if (!cx_->zone()->ensureJitZoneExists(cx_)) {
return DummyCode();
}
masm_.bind(&entry_label_);
createStackFrame();
initFrameAndRegs();
masm_.jump(&start_label_);
successHandler();
exitHandler();
backtrackHandler();
stackOverflowHandler();
Linker linker(masm_);
JitCode* code = linker.newCode(cx_, js::jit::CodeKind::RegExp);
if (!code) {
return DummyCode();
}
for (LabelPatch& lp : labelPatches_) {
Assembler::PatchDataWithValueCheck(CodeLocationLabel(code, lp.patchOffset_),
ImmPtr(code->raw() + lp.labelOffset_),
ImmPtr(nullptr));
}
CollectPerfSpewerJitCodeProfile(code, "RegExp");
#ifdef MOZ_VTUNE
js::vtune::MarkStub(code, "RegExp");
#endif
return Handle<HeapObject>(JS::PrivateGCThingValue(code), isolate());
}
/*
* The stack will have the following structure:
* sp-> - FrameData
* - inputStart
* - backtrack stack base
* - matches
* - numMatches
* - Registers
* - Capture positions
* - Scratch registers
* --- frame alignment ---
* - Saved register area
* fp-> - Frame pointer
* - Return address
*/
void SMRegExpMacroAssembler::createStackFrame() {
#ifdef JS_CODEGEN_ARM64
// ARM64 communicates stack address via SP, but uses a pseudo-sp (PSP) for
// addressing. The register we use for PSP may however also be used by
// calling code, and it is nonvolatile, so save it. Do this as a special
// case first because the generic save/restore code needs the PSP to be
// initialized already.
MOZ_ASSERT(js::jit::PseudoStackPointer64.Is(masm_.GetStackPointer64()));
masm_.Str(js::jit::PseudoStackPointer64,
vixl::MemOperand(js::jit::sp, -16, vixl::PreIndex));
// Initialize the PSP from the SP.
masm_.initPseudoStackPtr();
#endif
masm_.Push(js::jit::FramePointer);
masm_.moveStackPtrTo(js::jit::FramePointer);
// Push non-volatile registers which might be modified by jitcode.
for (GeneralRegisterForwardIterator iter(savedRegisters_); iter.more();
++iter) {
masm_.Push(*iter);
}
// The pointer to InputOutputData is passed as the first argument.
// On x86 we have to load it off the stack into temp0_.
// On other platforms it is already in a register.
#ifdef JS_CODEGEN_X86
Address ioDataAddr(js::jit::FramePointer, 2 * sizeof(void*));
masm_.loadPtr(ioDataAddr, temp0_);
#else
if (js::jit::IntArgReg0 != temp0_) {
masm_.movePtr(js::jit::IntArgReg0, temp0_);
}
#endif
// Start a new stack frame.
size_t frameBytes = sizeof(FrameData) + num_registers_ * sizeof(void*);
frameSize_ = js::jit::StackDecrementForCall(js::jit::ABIStackAlignment,
masm_.framePushed(), frameBytes);
masm_.reserveStack(frameSize_);
masm_.checkStackAlignment();
// Check if we have space on the stack. Use the *NoInterrupt stack limit to
// avoid failing repeatedly when the regex code is called from Ion JIT code.
js::jit::Label stack_ok;
AbsoluteAddress limit_addr(cx_->addressOfJitStackLimitNoInterrupt());
masm_.branchStackPtrRhs(Assembler::Below, limit_addr, &stack_ok);
// There is not enough space on the stack. Exit with an exception.
masm_.movePtr(ImmWord(int32_t(js::RegExpRunStatus::Error)), temp0_);
masm_.jump(&exit_label_);
masm_.bind(&stack_ok);
}
void SMRegExpMacroAssembler::initFrameAndRegs() {
// At this point, an uninitialized stack frame has been created,
// and the address of the InputOutputData is in temp0_.
Register ioDataReg = temp0_;
Register matchesReg = temp1_;
masm_.loadPtr(Address(ioDataReg, offsetof(InputOutputData, matches)),
matchesReg);
// Initialize output registers
// Use |backtrack_stack_pointer_| as an additional temp register. This is safe
// because we haven't yet written any data to |backtrack_stack_pointer_|.
Register extraTemp = backtrack_stack_pointer_;
masm_.loadPtr(Address(matchesReg, MatchPairs::offsetOfPairs()), extraTemp);
masm_.storePtr(extraTemp, matches());
masm_.load32(Address(matchesReg, MatchPairs::offsetOfPairCount()), extraTemp);
masm_.store32(extraTemp, numMatches());
#ifdef DEBUG
// Bounds-check numMatches.
js::jit::Label enoughRegisters;
masm_.branchPtr(Assembler::GreaterThanOrEqual, extraTemp,
ImmWord(num_capture_registers_ / 2), &enoughRegisters);
masm_.assumeUnreachable("Not enough output pairs for RegExp");
masm_.bind(&enoughRegisters);
#endif
// Load input start pointer.
masm_.loadPtr(Address(ioDataReg, offsetof(InputOutputData, inputStart)),
current_position_);
// Load input end pointer
masm_.loadPtr(Address(ioDataReg, offsetof(InputOutputData, inputEnd)),
input_end_pointer_);
// Set up input position to be negative offset from string end.
masm_.subPtr(input_end_pointer_, current_position_);
// Store inputStart
masm_.storePtr(current_position_, inputStart());
// Load start index
Register startIndexReg = temp1_;
masm_.loadPtr(Address(ioDataReg, offsetof(InputOutputData, startIndex)),
startIndexReg);
masm_.computeEffectiveAddress(
BaseIndex(current_position_, startIndexReg, factor()), current_position_);
// Initialize current_character_.
// Load newline if index is at start, or previous character otherwise.
js::jit::Label start_regexp;
js::jit::Label load_previous_character;
masm_.branchPtr(Assembler::NotEqual, startIndexReg, ImmWord(0),
&load_previous_character);
masm_.movePtr(ImmWord('\n'), current_character_);
masm_.jump(&start_regexp);
masm_.bind(&load_previous_character);
LoadCurrentCharacterUnchecked(-1, 1);
masm_.bind(&start_regexp);
// Initialize captured registers with inputStart - 1
MOZ_ASSERT(num_capture_registers_ > 0);
Register inputStartMinusOneReg = temp0_;
masm_.loadPtr(inputStart(), inputStartMinusOneReg);
masm_.subPtr(Imm32(char_size()), inputStartMinusOneReg);
if (num_capture_registers_ > 8) {
masm_.movePtr(ImmWord(register_offset(0)), temp1_);
js::jit::Label init_loop;
masm_.bind(&init_loop);
masm_.storePtr(inputStartMinusOneReg, BaseIndex(masm_.getStackPointer(),
temp1_, js::jit::TimesOne));
masm_.addPtr(ImmWord(sizeof(void*)), temp1_);
masm_.branchPtr(Assembler::LessThan, temp1_,
ImmWord(register_offset(num_capture_registers_)),
&init_loop);
} else {
// Unroll the loop
for (int i = 0; i < num_capture_registers_; i++) {
masm_.storePtr(inputStartMinusOneReg, register_location(i));
}
}
// Initialize backtrack stack pointer
masm_.loadPtr(AbsoluteAddress(ExternalReference::TopOfRegexpStack(isolate())),
backtrack_stack_pointer_);
masm_.storePtr(backtrack_stack_pointer_, backtrackStackBase());
}
// Called when we find a match. May not be generated if we can
// determine ahead of time that a regexp cannot match: for example,
// when compiling /\u1e9e/ for latin-1 inputs.
void SMRegExpMacroAssembler::successHandler() {
if (!success_label_.used()) {
return;
}
masm_.bind(&success_label_);
// Copy captures to the MatchPairs pointed to by the InputOutputData.
// Captures are stored as positions, which are negative byte offsets
// from the end of the string. We must convert them to actual
// indices.
//
// Index: [ 0 ][ 1 ][ 2 ][ 3 ][ 4 ][ 5 ][END]
// Pos (1-byte): [-6 ][-5 ][-4 ][-3 ][-2 ][-1 ][ 0 ] // IS = -6
// Pos (2-byte): [-12][-10][-8 ][-6 ][-4 ][-2 ][ 0 ] // IS = -12
//
// To convert a position to an index, we subtract InputStart, and
// divide the result by char_size.
Register matchesReg = temp1_;
masm_.loadPtr(matches(), matchesReg);
// Use |backtrack_stack_pointer_| as an additional temp register. This is safe
// because we don't read from |backtrack_stack_pointer_| after this point.
Register extraTemp = backtrack_stack_pointer_;
Register inputStartReg = extraTemp;
masm_.loadPtr(inputStart(), inputStartReg);
for (int i = 0; i < num_capture_registers_; i++) {
masm_.loadPtr(register_location(i), temp0_);
masm_.subPtr(inputStartReg, temp0_);
if (mode_ == UC16) {
masm_.rshiftPtrArithmetic(Imm32(1), temp0_);
}
masm_.store32(temp0_, Address(matchesReg, i * sizeof(int32_t)));
}
masm_.movePtr(ImmWord(int32_t(js::RegExpRunStatus::Success)), temp0_);
// This falls through to the exit handler.
}
void SMRegExpMacroAssembler::exitHandler() {
masm_.bind(&exit_label_);
if (temp0_ != js::jit::ReturnReg) {
masm_.movePtr(temp0_, js::jit::ReturnReg);
}
masm_.freeStack(frameSize_);
// Restore registers which were saved on entry
for (GeneralRegisterBackwardIterator iter(savedRegisters_); iter.more();
++iter) {
masm_.Pop(*iter);
}
masm_.Pop(js::jit::FramePointer);
#ifdef JS_CODEGEN_ARM64
// Now restore the value that was in the PSP register on entry, and return.
// Obtain the correct SP from the PSP.
masm_.Mov(js::jit::sp, js::jit::PseudoStackPointer64);
// Restore the saved value of the PSP register, this value is whatever the
// caller had saved in it, not any actual SP value, and it must not be
// overwritten subsequently.
masm_.Ldr(js::jit::PseudoStackPointer64,
vixl::MemOperand(js::jit::sp, 16, vixl::PostIndex));
// Perform a plain Ret(), as abiret() will move SP <- PSP and that is wrong.
masm_.Ret(vixl::lr);
#else
masm_.abiret();
#endif
if (exit_with_exception_label_.used()) {
masm_.bind(&exit_with_exception_label_);
// Exit with an error result to signal thrown exception
masm_.movePtr(ImmWord(int32_t(js::RegExpRunStatus::Error)), temp0_);
masm_.jump(&exit_label_);
}
}
void SMRegExpMacroAssembler::backtrackHandler() {
if (!backtrack_label_.used()) {
return;
}
masm_.bind(&backtrack_label_);
Backtrack();
}
void SMRegExpMacroAssembler::stackOverflowHandler() {
if (!stack_overflow_label_.used()) {
return;
}
js::jit::AutoCreatedBy acb(masm_,
"SMRegExpMacroAssembler::stackOverflowHandler");
// Called if the backtrack-stack limit has been hit.
masm_.bind(&stack_overflow_label_);
// Load argument
masm_.movePtr(ImmPtr(isolate()->regexp_stack()), temp1_);
// Save registers before calling C function
LiveGeneralRegisterSet volatileRegs(GeneralRegisterSet::Volatile());
#ifdef JS_USE_LINK_REGISTER
masm_.pushReturnAddress();
#endif
// Adjust for the return address on the stack.
size_t frameOffset = sizeof(void*);
volatileRegs.takeUnchecked(temp0_);
volatileRegs.takeUnchecked(temp1_);
masm_.PushRegsInMask(volatileRegs);
using Fn = bool (*)(RegExpStack* regexp_stack);
masm_.setupUnalignedABICall(temp0_);
masm_.passABIArg(temp1_);
masm_.callWithABI<Fn, ::js::irregexp::GrowBacktrackStack>();
masm_.storeCallBoolResult(temp0_);
masm_.PopRegsInMask(volatileRegs);
// If GrowBacktrackStack returned false, we have failed to grow the
// stack, and must exit with a stack-overflow exception. Do this in
// the caller so that the stack is adjusted by our return instruction.
js::jit::Label overflow_return;
masm_.branchTest32(Assembler::Zero, temp0_, temp0_, &overflow_return);
// Otherwise, store the new backtrack stack base and recompute the new
// top of the stack.
Address bsbAddress(masm_.getStackPointer(),
offsetof(FrameData, backtrackStackBase) + frameOffset);
masm_.subPtr(bsbAddress, backtrack_stack_pointer_);
masm_.loadPtr(AbsoluteAddress(ExternalReference::TopOfRegexpStack(isolate())),
temp1_);
masm_.storePtr(temp1_, bsbAddress);
masm_.addPtr(temp1_, backtrack_stack_pointer_);
// Resume execution in calling code.
masm_.bind(&overflow_return);
masm_.ret();
}
// This is only used by tracing code.
// The return value doesn't matter.
RegExpMacroAssembler::IrregexpImplementation
SMRegExpMacroAssembler::Implementation() {
return kBytecodeImplementation;
}
// Compare two strings in `/i` mode (ignoreCase, but not unicode).
/*static */
uint32_t SMRegExpMacroAssembler::CaseInsensitiveCompareNonUnicode(
const char16_t* substring1, const char16_t* substring2, size_t byteLength) {
js::AutoUnsafeCallWithABI unsafe;
MOZ_ASSERT(byteLength % sizeof(char16_t) == 0);
size_t length = byteLength / sizeof(char16_t);
for (size_t i = 0; i < length; i++) {
char16_t c1 = substring1[i];
char16_t c2 = substring2[i];
if (c1 != c2) {
#ifdef JS_HAS_INTL_API
// Non-unicode regexps have weird case-folding rules.
c1 = RegExpCaseFolding::Canonicalize(c1);
c2 = RegExpCaseFolding::Canonicalize(c2);
#else
// If we aren't building with ICU, fall back to `/iu` mode. The only
// differences are in corner cases.
c1 = js::unicode::FoldCase(c1);
c2 = js::unicode::FoldCase(c2);
#endif
if (c1 != c2) {
return 0;
}
}
}
return 1;
}
// Compare two strings in `/iu` mode (ignoreCase and unicode).
/*static */
uint32_t SMRegExpMacroAssembler::CaseInsensitiveCompareUnicode(
const char16_t* substring1, const char16_t* substring2, size_t byteLength) {
js::AutoUnsafeCallWithABI unsafe;
MOZ_ASSERT(byteLength % sizeof(char16_t) == 0);
size_t length = byteLength / sizeof(char16_t);
for (size_t i = 0; i < length; i++) {
char16_t c1 = substring1[i];
char16_t c2 = substring2[i];
if (c1 != c2) {
// Unicode regexps use the common and simple case-folding
// mappings of the Unicode Character Database.
c1 = js::unicode::FoldCase(c1);
c2 = js::unicode::FoldCase(c2);
if (c1 != c2) {
return 0;
}
}
}
return 1;
}
/* static */
bool SMRegExpMacroAssembler::GrowBacktrackStack(RegExpStack* regexp_stack) {
js::AutoUnsafeCallWithABI unsafe;
size_t size = regexp_stack->memory_size();
return !!regexp_stack->EnsureCapacity(size * 2);
}
bool SMRegExpMacroAssembler::CanReadUnaligned() const {
#if defined(JS_CODEGEN_ARM)
return !js::jit::HasAlignmentFault();
#elif defined(JS_CODEGEN_MIPS32) || defined(JS_CODEGEN_MIPS64)
return false;
#else
return true;
#endif
}
} // namespace internal
} // namespace v8