deps/v8/src/arm64/regexp-macro-assembler-arm64.cc
// Copyright 2013 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 "src/v8.h"
#if V8_TARGET_ARCH_ARM64
#include "src/code-stubs.h"
#include "src/cpu-profiler.h"
#include "src/log.h"
#include "src/macro-assembler.h"
#include "src/regexp-macro-assembler.h"
#include "src/regexp-stack.h"
#include "src/unicode.h"
#include "src/arm64/regexp-macro-assembler-arm64.h"
namespace v8 {
namespace internal {
#ifndef V8_INTERPRETED_REGEXP
/*
* This assembler uses the following register assignment convention:
* - w19 : Used to temporarely store a value before a call to C code.
* See CheckNotBackReferenceIgnoreCase.
* - x20 : Pointer to the current code object (Code*),
* it includes the heap object tag.
* - w21 : Current position in input, as negative offset from
* the end of the string. Please notice that this is
* the byte offset, not the character offset!
* - w22 : Currently loaded character. Must be loaded using
* LoadCurrentCharacter before using any of the dispatch methods.
* - x23 : Points to tip of backtrack stack.
* - w24 : Position of the first character minus one: non_position_value.
* Used to initialize capture registers.
* - x25 : Address at the end of the input string: input_end.
* Points to byte after last character in input.
* - x26 : Address at the start of the input string: input_start.
* - w27 : Where to start in the input string.
* - x28 : Output array pointer.
* - x29/fp : Frame pointer. Used to access arguments, local variables and
* RegExp registers.
* - x16/x17 : IP registers, used by assembler. Very volatile.
* - csp : Points to tip of C stack.
*
* - x0-x7 : Used as a cache to store 32 bit capture registers. These
* registers need to be retained every time a call to C code
* is done.
*
* The remaining registers are free for computations.
* Each call to a public method should retain this convention.
*
* The stack will have the following structure:
*
* Location Name Description
* (as referred to in
* the code)
*
* - fp[104] isolate Address of the current isolate.
* - fp[96] return_address Secondary link/return address
* used by an exit frame if this is a
* native call.
* ^^^ csp when called ^^^
* - fp[88] lr Return from the RegExp code.
* - fp[80] r29 Old frame pointer (CalleeSaved).
* - fp[0..72] r19-r28 Backup of CalleeSaved registers.
* - fp[-8] direct_call 1 => Direct call from JavaScript code.
* 0 => Call through the runtime system.
* - fp[-16] stack_base High end of the memory area to use as
* the backtracking stack.
* - fp[-24] output_size Output may fit multiple sets of matches.
* - fp[-32] input Handle containing the input string.
* - fp[-40] success_counter
* ^^^^^^^^^^^^^ From here and downwards we store 32 bit values ^^^^^^^^^^^^^
* - fp[-44] register N Capture registers initialized with
* - fp[-48] register N + 1 non_position_value.
* ... The first kNumCachedRegisters (N) registers
* ... are cached in x0 to x7.
* ... Only positions must be stored in the first
* - ... num_saved_registers_ registers.
* - ...
* - register N + num_registers - 1
* ^^^^^^^^^ csp ^^^^^^^^^
*
* The first num_saved_registers_ registers are initialized to point to
* "character -1" in the string (i.e., char_size() bytes before the first
* character of the string). The remaining registers start out as garbage.
*
* The data up to the return address must be placed there by the calling
* code and the remaining arguments are passed in registers, e.g. by calling the
* code entry as cast to a function with the signature:
* int (*match)(String* input,
* int start_offset,
* Address input_start,
* Address input_end,
* int* output,
* int output_size,
* Address stack_base,
* bool direct_call = false,
* Address secondary_return_address, // Only used by native call.
* Isolate* isolate)
* The call is performed by NativeRegExpMacroAssembler::Execute()
* (in regexp-macro-assembler.cc) via the CALL_GENERATED_REGEXP_CODE macro
* in arm64/simulator-arm64.h.
* When calling as a non-direct call (i.e., from C++ code), the return address
* area is overwritten with the LR register by the RegExp code. When doing a
* direct call from generated code, the return address is placed there by
* the calling code, as in a normal exit frame.
*/
#define __ ACCESS_MASM(masm_)
RegExpMacroAssemblerARM64::RegExpMacroAssemblerARM64(
Mode mode,
int registers_to_save,
Zone* zone)
: NativeRegExpMacroAssembler(zone),
masm_(new MacroAssembler(zone->isolate(), NULL, kRegExpCodeSize)),
mode_(mode),
num_registers_(registers_to_save),
num_saved_registers_(registers_to_save),
entry_label_(),
start_label_(),
success_label_(),
backtrack_label_(),
exit_label_() {
__ SetStackPointer(csp);
DCHECK_EQ(0, registers_to_save % 2);
// We can cache at most 16 W registers in x0-x7.
STATIC_ASSERT(kNumCachedRegisters <= 16);
STATIC_ASSERT((kNumCachedRegisters % 2) == 0);
__ B(&entry_label_); // We'll write the entry code later.
__ Bind(&start_label_); // And then continue from here.
}
RegExpMacroAssemblerARM64::~RegExpMacroAssemblerARM64() {
delete masm_;
// Unuse labels in case we throw away the assembler without calling GetCode.
entry_label_.Unuse();
start_label_.Unuse();
success_label_.Unuse();
backtrack_label_.Unuse();
exit_label_.Unuse();
check_preempt_label_.Unuse();
stack_overflow_label_.Unuse();
}
int RegExpMacroAssemblerARM64::stack_limit_slack() {
return RegExpStack::kStackLimitSlack;
}
void RegExpMacroAssemblerARM64::AdvanceCurrentPosition(int by) {
if (by != 0) {
__ Add(current_input_offset(),
current_input_offset(), by * char_size());
}
}
void RegExpMacroAssemblerARM64::AdvanceRegister(int reg, int by) {
DCHECK((reg >= 0) && (reg < num_registers_));
if (by != 0) {
Register to_advance;
RegisterState register_state = GetRegisterState(reg);
switch (register_state) {
case STACKED:
__ Ldr(w10, register_location(reg));
__ Add(w10, w10, by);
__ Str(w10, register_location(reg));
break;
case CACHED_LSW:
to_advance = GetCachedRegister(reg);
__ Add(to_advance, to_advance, by);
break;
case CACHED_MSW:
to_advance = GetCachedRegister(reg);
__ Add(to_advance, to_advance,
static_cast<int64_t>(by) << kWRegSizeInBits);
break;
default:
UNREACHABLE();
break;
}
}
}
void RegExpMacroAssemblerARM64::Backtrack() {
CheckPreemption();
Pop(w10);
__ Add(x10, code_pointer(), Operand(w10, UXTW));
__ Br(x10);
}
void RegExpMacroAssemblerARM64::Bind(Label* label) {
__ Bind(label);
}
void RegExpMacroAssemblerARM64::CheckCharacter(uint32_t c, Label* on_equal) {
CompareAndBranchOrBacktrack(current_character(), c, eq, on_equal);
}
void RegExpMacroAssemblerARM64::CheckCharacterGT(uc16 limit,
Label* on_greater) {
CompareAndBranchOrBacktrack(current_character(), limit, hi, on_greater);
}
void RegExpMacroAssemblerARM64::CheckAtStart(Label* on_at_start) {
Label not_at_start;
// Did we start the match at the start of the input string?
CompareAndBranchOrBacktrack(start_offset(), 0, ne, ¬_at_start);
// If we did, are we still at the start of the input string?
__ Add(x10, input_end(), Operand(current_input_offset(), SXTW));
__ Cmp(x10, input_start());
BranchOrBacktrack(eq, on_at_start);
__ Bind(¬_at_start);
}
void RegExpMacroAssemblerARM64::CheckNotAtStart(Label* on_not_at_start) {
// Did we start the match at the start of the input string?
CompareAndBranchOrBacktrack(start_offset(), 0, ne, on_not_at_start);
// If we did, are we still at the start of the input string?
__ Add(x10, input_end(), Operand(current_input_offset(), SXTW));
__ Cmp(x10, input_start());
BranchOrBacktrack(ne, on_not_at_start);
}
void RegExpMacroAssemblerARM64::CheckCharacterLT(uc16 limit, Label* on_less) {
CompareAndBranchOrBacktrack(current_character(), limit, lo, on_less);
}
void RegExpMacroAssemblerARM64::CheckCharacters(Vector<const uc16> str,
int cp_offset,
Label* on_failure,
bool check_end_of_string) {
// This method is only ever called from the cctests.
if (check_end_of_string) {
// Is last character of required match inside string.
CheckPosition(cp_offset + str.length() - 1, on_failure);
}
Register characters_address = x11;
__ Add(characters_address,
input_end(),
Operand(current_input_offset(), SXTW));
if (cp_offset != 0) {
__ Add(characters_address, characters_address, cp_offset * char_size());
}
for (int i = 0; i < str.length(); i++) {
if (mode_ == ASCII) {
__ Ldrb(w10, MemOperand(characters_address, 1, PostIndex));
DCHECK(str[i] <= String::kMaxOneByteCharCode);
} else {
__ Ldrh(w10, MemOperand(characters_address, 2, PostIndex));
}
CompareAndBranchOrBacktrack(w10, str[i], ne, on_failure);
}
}
void RegExpMacroAssemblerARM64::CheckGreedyLoop(Label* on_equal) {
__ Ldr(w10, MemOperand(backtrack_stackpointer()));
__ Cmp(current_input_offset(), w10);
__ Cset(x11, eq);
__ Add(backtrack_stackpointer(),
backtrack_stackpointer(), Operand(x11, LSL, kWRegSizeLog2));
BranchOrBacktrack(eq, on_equal);
}
void RegExpMacroAssemblerARM64::CheckNotBackReferenceIgnoreCase(
int start_reg,
Label* on_no_match) {
Label fallthrough;
Register capture_start_offset = w10;
// Save the capture length in a callee-saved register so it will
// be preserved if we call a C helper.
Register capture_length = w19;
DCHECK(kCalleeSaved.IncludesAliasOf(capture_length));
// Find length of back-referenced capture.
DCHECK((start_reg % 2) == 0);
if (start_reg < kNumCachedRegisters) {
__ Mov(capture_start_offset.X(), GetCachedRegister(start_reg));
__ Lsr(x11, GetCachedRegister(start_reg), kWRegSizeInBits);
} else {
__ Ldp(w11, capture_start_offset, capture_location(start_reg, x10));
}
__ Sub(capture_length, w11, capture_start_offset); // Length to check.
// Succeed on empty capture (including no capture).
__ Cbz(capture_length, &fallthrough);
// Check that there are enough characters left in the input.
__ Cmn(capture_length, current_input_offset());
BranchOrBacktrack(gt, on_no_match);
if (mode_ == ASCII) {
Label success;
Label fail;
Label loop_check;
Register capture_start_address = x12;
Register capture_end_addresss = x13;
Register current_position_address = x14;
__ Add(capture_start_address,
input_end(),
Operand(capture_start_offset, SXTW));
__ Add(capture_end_addresss,
capture_start_address,
Operand(capture_length, SXTW));
__ Add(current_position_address,
input_end(),
Operand(current_input_offset(), SXTW));
Label loop;
__ Bind(&loop);
__ Ldrb(w10, MemOperand(capture_start_address, 1, PostIndex));
__ Ldrb(w11, MemOperand(current_position_address, 1, PostIndex));
__ Cmp(w10, w11);
__ B(eq, &loop_check);
// Mismatch, try case-insensitive match (converting letters to lower-case).
__ Orr(w10, w10, 0x20); // Convert capture character to lower-case.
__ Orr(w11, w11, 0x20); // Also convert input character.
__ Cmp(w11, w10);
__ B(ne, &fail);
__ Sub(w10, w10, 'a');
__ Cmp(w10, 'z' - 'a'); // Is w10 a lowercase letter?
__ B(ls, &loop_check); // In range 'a'-'z'.
// Latin-1: Check for values in range [224,254] but not 247.
__ Sub(w10, w10, 224 - 'a');
__ Cmp(w10, 254 - 224);
__ Ccmp(w10, 247 - 224, ZFlag, ls); // Check for 247.
__ B(eq, &fail); // Weren't Latin-1 letters.
__ Bind(&loop_check);
__ Cmp(capture_start_address, capture_end_addresss);
__ B(lt, &loop);
__ B(&success);
__ Bind(&fail);
BranchOrBacktrack(al, on_no_match);
__ Bind(&success);
// Compute new value of character position after the matched part.
__ Sub(current_input_offset().X(), current_position_address, input_end());
if (masm_->emit_debug_code()) {
__ Cmp(current_input_offset().X(), Operand(current_input_offset(), SXTW));
__ Ccmp(current_input_offset(), 0, NoFlag, eq);
// The current input offset should be <= 0, and fit in a W register.
__ Check(le, kOffsetOutOfRange);
}
} else {
DCHECK(mode_ == UC16);
int argument_count = 4;
// The cached registers need to be retained.
CPURegList cached_registers(CPURegister::kRegister, kXRegSizeInBits, 0, 7);
DCHECK((cached_registers.Count() * 2) == kNumCachedRegisters);
__ PushCPURegList(cached_registers);
// Put arguments into arguments registers.
// Parameters are
// x0: Address byte_offset1 - Address captured substring's start.
// x1: Address byte_offset2 - Address of current character position.
// w2: size_t byte_length - length of capture in bytes(!)
// x3: Isolate* isolate
// Address of start of capture.
__ Add(x0, input_end(), Operand(capture_start_offset, SXTW));
// Length of capture.
__ Mov(w2, capture_length);
// Address of current input position.
__ Add(x1, input_end(), Operand(current_input_offset(), SXTW));
// Isolate.
__ Mov(x3, ExternalReference::isolate_address(isolate()));
{
AllowExternalCallThatCantCauseGC scope(masm_);
ExternalReference function =
ExternalReference::re_case_insensitive_compare_uc16(isolate());
__ CallCFunction(function, argument_count);
}
// Check if function returned non-zero for success or zero for failure.
// x0 is one of the registers used as a cache so it must be tested before
// the cache is restored.
__ Cmp(x0, 0);
__ PopCPURegList(cached_registers);
BranchOrBacktrack(eq, on_no_match);
// On success, increment position by length of capture.
__ Add(current_input_offset(), current_input_offset(), capture_length);
}
__ Bind(&fallthrough);
}
void RegExpMacroAssemblerARM64::CheckNotBackReference(
int start_reg,
Label* on_no_match) {
Label fallthrough;
Register capture_start_address = x12;
Register capture_end_address = x13;
Register current_position_address = x14;
Register capture_length = w15;
// Find length of back-referenced capture.
DCHECK((start_reg % 2) == 0);
if (start_reg < kNumCachedRegisters) {
__ Mov(x10, GetCachedRegister(start_reg));
__ Lsr(x11, GetCachedRegister(start_reg), kWRegSizeInBits);
} else {
__ Ldp(w11, w10, capture_location(start_reg, x10));
}
__ Sub(capture_length, w11, w10); // Length to check.
// Succeed on empty capture (including no capture).
__ Cbz(capture_length, &fallthrough);
// Check that there are enough characters left in the input.
__ Cmn(capture_length, current_input_offset());
BranchOrBacktrack(gt, on_no_match);
// Compute pointers to match string and capture string
__ Add(capture_start_address, input_end(), Operand(w10, SXTW));
__ Add(capture_end_address,
capture_start_address,
Operand(capture_length, SXTW));
__ Add(current_position_address,
input_end(),
Operand(current_input_offset(), SXTW));
Label loop;
__ Bind(&loop);
if (mode_ == ASCII) {
__ Ldrb(w10, MemOperand(capture_start_address, 1, PostIndex));
__ Ldrb(w11, MemOperand(current_position_address, 1, PostIndex));
} else {
DCHECK(mode_ == UC16);
__ Ldrh(w10, MemOperand(capture_start_address, 2, PostIndex));
__ Ldrh(w11, MemOperand(current_position_address, 2, PostIndex));
}
__ Cmp(w10, w11);
BranchOrBacktrack(ne, on_no_match);
__ Cmp(capture_start_address, capture_end_address);
__ B(lt, &loop);
// Move current character position to position after match.
__ Sub(current_input_offset().X(), current_position_address, input_end());
if (masm_->emit_debug_code()) {
__ Cmp(current_input_offset().X(), Operand(current_input_offset(), SXTW));
__ Ccmp(current_input_offset(), 0, NoFlag, eq);
// The current input offset should be <= 0, and fit in a W register.
__ Check(le, kOffsetOutOfRange);
}
__ Bind(&fallthrough);
}
void RegExpMacroAssemblerARM64::CheckNotCharacter(unsigned c,
Label* on_not_equal) {
CompareAndBranchOrBacktrack(current_character(), c, ne, on_not_equal);
}
void RegExpMacroAssemblerARM64::CheckCharacterAfterAnd(uint32_t c,
uint32_t mask,
Label* on_equal) {
__ And(w10, current_character(), mask);
CompareAndBranchOrBacktrack(w10, c, eq, on_equal);
}
void RegExpMacroAssemblerARM64::CheckNotCharacterAfterAnd(unsigned c,
unsigned mask,
Label* on_not_equal) {
__ And(w10, current_character(), mask);
CompareAndBranchOrBacktrack(w10, c, ne, on_not_equal);
}
void RegExpMacroAssemblerARM64::CheckNotCharacterAfterMinusAnd(
uc16 c,
uc16 minus,
uc16 mask,
Label* on_not_equal) {
DCHECK(minus < String::kMaxUtf16CodeUnit);
__ Sub(w10, current_character(), minus);
__ And(w10, w10, mask);
CompareAndBranchOrBacktrack(w10, c, ne, on_not_equal);
}
void RegExpMacroAssemblerARM64::CheckCharacterInRange(
uc16 from,
uc16 to,
Label* on_in_range) {
__ Sub(w10, current_character(), from);
// Unsigned lower-or-same condition.
CompareAndBranchOrBacktrack(w10, to - from, ls, on_in_range);
}
void RegExpMacroAssemblerARM64::CheckCharacterNotInRange(
uc16 from,
uc16 to,
Label* on_not_in_range) {
__ Sub(w10, current_character(), from);
// Unsigned higher condition.
CompareAndBranchOrBacktrack(w10, to - from, hi, on_not_in_range);
}
void RegExpMacroAssemblerARM64::CheckBitInTable(
Handle<ByteArray> table,
Label* on_bit_set) {
__ Mov(x11, Operand(table));
if ((mode_ != ASCII) || (kTableMask != String::kMaxOneByteCharCode)) {
__ And(w10, current_character(), kTableMask);
__ Add(w10, w10, ByteArray::kHeaderSize - kHeapObjectTag);
} else {
__ Add(w10, current_character(), ByteArray::kHeaderSize - kHeapObjectTag);
}
__ Ldrb(w11, MemOperand(x11, w10, UXTW));
CompareAndBranchOrBacktrack(w11, 0, ne, on_bit_set);
}
bool RegExpMacroAssemblerARM64::CheckSpecialCharacterClass(uc16 type,
Label* on_no_match) {
// Range checks (c in min..max) are generally implemented by an unsigned
// (c - min) <= (max - min) check
switch (type) {
case 's':
// Match space-characters
if (mode_ == ASCII) {
// One byte space characters are '\t'..'\r', ' ' and \u00a0.
Label success;
// Check for ' ' or 0x00a0.
__ Cmp(current_character(), ' ');
__ Ccmp(current_character(), 0x00a0, ZFlag, ne);
__ B(eq, &success);
// Check range 0x09..0x0d.
__ Sub(w10, current_character(), '\t');
CompareAndBranchOrBacktrack(w10, '\r' - '\t', hi, on_no_match);
__ Bind(&success);
return true;
}
return false;
case 'S':
// The emitted code for generic character classes is good enough.
return false;
case 'd':
// Match ASCII digits ('0'..'9').
__ Sub(w10, current_character(), '0');
CompareAndBranchOrBacktrack(w10, '9' - '0', hi, on_no_match);
return true;
case 'D':
// Match ASCII non-digits.
__ Sub(w10, current_character(), '0');
CompareAndBranchOrBacktrack(w10, '9' - '0', ls, on_no_match);
return true;
case '.': {
// Match non-newlines (not 0x0a('\n'), 0x0d('\r'), 0x2028 and 0x2029)
// Here we emit the conditional branch only once at the end to make branch
// prediction more efficient, even though we could branch out of here
// as soon as a character matches.
__ Cmp(current_character(), 0x0a);
__ Ccmp(current_character(), 0x0d, ZFlag, ne);
if (mode_ == UC16) {
__ Sub(w10, current_character(), 0x2028);
// If the Z flag was set we clear the flags to force a branch.
__ Ccmp(w10, 0x2029 - 0x2028, NoFlag, ne);
// ls -> !((C==1) && (Z==0))
BranchOrBacktrack(ls, on_no_match);
} else {
BranchOrBacktrack(eq, on_no_match);
}
return true;
}
case 'n': {
// Match newlines (0x0a('\n'), 0x0d('\r'), 0x2028 and 0x2029)
// We have to check all 4 newline characters before emitting
// the conditional branch.
__ Cmp(current_character(), 0x0a);
__ Ccmp(current_character(), 0x0d, ZFlag, ne);
if (mode_ == UC16) {
__ Sub(w10, current_character(), 0x2028);
// If the Z flag was set we clear the flags to force a fall-through.
__ Ccmp(w10, 0x2029 - 0x2028, NoFlag, ne);
// hi -> (C==1) && (Z==0)
BranchOrBacktrack(hi, on_no_match);
} else {
BranchOrBacktrack(ne, on_no_match);
}
return true;
}
case 'w': {
if (mode_ != ASCII) {
// Table is 128 entries, so all ASCII characters can be tested.
CompareAndBranchOrBacktrack(current_character(), 'z', hi, on_no_match);
}
ExternalReference map = ExternalReference::re_word_character_map();
__ Mov(x10, map);
__ Ldrb(w10, MemOperand(x10, current_character(), UXTW));
CompareAndBranchOrBacktrack(w10, 0, eq, on_no_match);
return true;
}
case 'W': {
Label done;
if (mode_ != ASCII) {
// Table is 128 entries, so all ASCII characters can be tested.
__ Cmp(current_character(), 'z');
__ B(hi, &done);
}
ExternalReference map = ExternalReference::re_word_character_map();
__ Mov(x10, map);
__ Ldrb(w10, MemOperand(x10, current_character(), UXTW));
CompareAndBranchOrBacktrack(w10, 0, ne, on_no_match);
__ Bind(&done);
return true;
}
case '*':
// Match any character.
return true;
// No custom implementation (yet): s(UC16), S(UC16).
default:
return false;
}
}
void RegExpMacroAssemblerARM64::Fail() {
__ Mov(w0, FAILURE);
__ B(&exit_label_);
}
Handle<HeapObject> RegExpMacroAssemblerARM64::GetCode(Handle<String> source) {
Label return_w0;
// Finalize code - write the entry point code now we know how many
// registers we need.
// Entry code:
__ Bind(&entry_label_);
// Arguments on entry:
// x0: String* input
// x1: int start_offset
// x2: byte* input_start
// x3: byte* input_end
// x4: int* output array
// x5: int output array size
// x6: Address stack_base
// x7: int direct_call
// The stack pointer should be csp on entry.
// csp[8]: address of the current isolate
// csp[0]: secondary link/return address used by native call
// Tell the system that we have a stack frame. Because the type is MANUAL, no
// code is generated.
FrameScope scope(masm_, StackFrame::MANUAL);
// Push registers on the stack, only push the argument registers that we need.
CPURegList argument_registers(x0, x5, x6, x7);
CPURegList registers_to_retain = kCalleeSaved;
DCHECK(kCalleeSaved.Count() == 11);
registers_to_retain.Combine(lr);
DCHECK(csp.Is(__ StackPointer()));
__ PushCPURegList(registers_to_retain);
__ PushCPURegList(argument_registers);
// Set frame pointer in place.
__ Add(frame_pointer(), csp, argument_registers.Count() * kPointerSize);
// Initialize callee-saved registers.
__ Mov(start_offset(), w1);
__ Mov(input_start(), x2);
__ Mov(input_end(), x3);
__ Mov(output_array(), x4);
// Set the number of registers we will need to allocate, that is:
// - success_counter (X register)
// - (num_registers_ - kNumCachedRegisters) (W registers)
int num_wreg_to_allocate = num_registers_ - kNumCachedRegisters;
// Do not allocate registers on the stack if they can all be cached.
if (num_wreg_to_allocate < 0) { num_wreg_to_allocate = 0; }
// Make room for the success_counter.
num_wreg_to_allocate += 2;
// Make sure the stack alignment will be respected.
int alignment = masm_->ActivationFrameAlignment();
DCHECK_EQ(alignment % 16, 0);
int align_mask = (alignment / kWRegSize) - 1;
num_wreg_to_allocate = (num_wreg_to_allocate + align_mask) & ~align_mask;
// Check if we have space on the stack.
Label stack_limit_hit;
Label stack_ok;
ExternalReference stack_limit =
ExternalReference::address_of_stack_limit(isolate());
__ Mov(x10, stack_limit);
__ Ldr(x10, MemOperand(x10));
__ Subs(x10, csp, x10);
// Handle it if the stack pointer is already below the stack limit.
__ B(ls, &stack_limit_hit);
// Check if there is room for the variable number of registers above
// the stack limit.
__ Cmp(x10, num_wreg_to_allocate * kWRegSize);
__ B(hs, &stack_ok);
// Exit with OutOfMemory exception. There is not enough space on the stack
// for our working registers.
__ Mov(w0, EXCEPTION);
__ B(&return_w0);
__ Bind(&stack_limit_hit);
CallCheckStackGuardState(x10);
// If returned value is non-zero, we exit with the returned value as result.
__ Cbnz(w0, &return_w0);
__ Bind(&stack_ok);
// Allocate space on stack.
__ Claim(num_wreg_to_allocate, kWRegSize);
// Initialize success_counter with 0.
__ Str(wzr, MemOperand(frame_pointer(), kSuccessCounter));
// Find negative length (offset of start relative to end).
__ Sub(x10, input_start(), input_end());
if (masm_->emit_debug_code()) {
// Check that the input string length is < 2^30.
__ Neg(x11, x10);
__ Cmp(x11, (1<<30) - 1);
__ Check(ls, kInputStringTooLong);
}
__ Mov(current_input_offset(), w10);
// The non-position value is used as a clearing value for the
// capture registers, it corresponds to the position of the first character
// minus one.
__ Sub(non_position_value(), current_input_offset(), char_size());
__ Sub(non_position_value(), non_position_value(),
Operand(start_offset(), LSL, (mode_ == UC16) ? 1 : 0));
// We can store this value twice in an X register for initializing
// on-stack registers later.
__ Orr(twice_non_position_value(),
non_position_value().X(),
Operand(non_position_value().X(), LSL, kWRegSizeInBits));
// Initialize code pointer register.
__ Mov(code_pointer(), Operand(masm_->CodeObject()));
Label load_char_start_regexp, start_regexp;
// Load newline if index is at start, previous character otherwise.
__ Cbnz(start_offset(), &load_char_start_regexp);
__ Mov(current_character(), '\n');
__ B(&start_regexp);
// Global regexp restarts matching here.
__ Bind(&load_char_start_regexp);
// Load previous char as initial value of current character register.
LoadCurrentCharacterUnchecked(-1, 1);
__ Bind(&start_regexp);
// Initialize on-stack registers.
if (num_saved_registers_ > 0) {
ClearRegisters(0, num_saved_registers_ - 1);
}
// Initialize backtrack stack pointer.
__ Ldr(backtrack_stackpointer(), MemOperand(frame_pointer(), kStackBase));
// Execute
__ B(&start_label_);
if (backtrack_label_.is_linked()) {
__ Bind(&backtrack_label_);
Backtrack();
}
if (success_label_.is_linked()) {
Register first_capture_start = w15;
// Save captures when successful.
__ Bind(&success_label_);
if (num_saved_registers_ > 0) {
// V8 expects the output to be an int32_t array.
Register capture_start = w12;
Register capture_end = w13;
Register input_length = w14;
// Copy captures to output.
// Get string length.
__ Sub(x10, input_end(), input_start());
if (masm_->emit_debug_code()) {
// Check that the input string length is < 2^30.
__ Cmp(x10, (1<<30) - 1);
__ Check(ls, kInputStringTooLong);
}
// input_start has a start_offset offset on entry. We need to include
// it when computing the length of the whole string.
if (mode_ == UC16) {
__ Add(input_length, start_offset(), Operand(w10, LSR, 1));
} else {
__ Add(input_length, start_offset(), w10);
}
// Copy the results to the output array from the cached registers first.
for (int i = 0;
(i < num_saved_registers_) && (i < kNumCachedRegisters);
i += 2) {
__ Mov(capture_start.X(), GetCachedRegister(i));
__ Lsr(capture_end.X(), capture_start.X(), kWRegSizeInBits);
if ((i == 0) && global_with_zero_length_check()) {
// Keep capture start for the zero-length check later.
__ Mov(first_capture_start, capture_start);
}
// Offsets need to be relative to the start of the string.
if (mode_ == UC16) {
__ Add(capture_start, input_length, Operand(capture_start, ASR, 1));
__ Add(capture_end, input_length, Operand(capture_end, ASR, 1));
} else {
__ Add(capture_start, input_length, capture_start);
__ Add(capture_end, input_length, capture_end);
}
// The output pointer advances for a possible global match.
__ Stp(capture_start,
capture_end,
MemOperand(output_array(), kPointerSize, PostIndex));
}
// Only carry on if there are more than kNumCachedRegisters capture
// registers.
int num_registers_left_on_stack =
num_saved_registers_ - kNumCachedRegisters;
if (num_registers_left_on_stack > 0) {
Register base = x10;
// There are always an even number of capture registers. A couple of
// registers determine one match with two offsets.
DCHECK_EQ(0, num_registers_left_on_stack % 2);
__ Add(base, frame_pointer(), kFirstCaptureOnStack);
// We can unroll the loop here, we should not unroll for less than 2
// registers.
STATIC_ASSERT(kNumRegistersToUnroll > 2);
if (num_registers_left_on_stack <= kNumRegistersToUnroll) {
for (int i = 0; i < num_registers_left_on_stack / 2; i++) {
__ Ldp(capture_end,
capture_start,
MemOperand(base, -kPointerSize, PostIndex));
if ((i == 0) && global_with_zero_length_check()) {
// Keep capture start for the zero-length check later.
__ Mov(first_capture_start, capture_start);
}
// Offsets need to be relative to the start of the string.
if (mode_ == UC16) {
__ Add(capture_start,
input_length,
Operand(capture_start, ASR, 1));
__ Add(capture_end, input_length, Operand(capture_end, ASR, 1));
} else {
__ Add(capture_start, input_length, capture_start);
__ Add(capture_end, input_length, capture_end);
}
// The output pointer advances for a possible global match.
__ Stp(capture_start,
capture_end,
MemOperand(output_array(), kPointerSize, PostIndex));
}
} else {
Label loop, start;
__ Mov(x11, num_registers_left_on_stack);
__ Ldp(capture_end,
capture_start,
MemOperand(base, -kPointerSize, PostIndex));
if (global_with_zero_length_check()) {
__ Mov(first_capture_start, capture_start);
}
__ B(&start);
__ Bind(&loop);
__ Ldp(capture_end,
capture_start,
MemOperand(base, -kPointerSize, PostIndex));
__ Bind(&start);
if (mode_ == UC16) {
__ Add(capture_start, input_length, Operand(capture_start, ASR, 1));
__ Add(capture_end, input_length, Operand(capture_end, ASR, 1));
} else {
__ Add(capture_start, input_length, capture_start);
__ Add(capture_end, input_length, capture_end);
}
// The output pointer advances for a possible global match.
__ Stp(capture_start,
capture_end,
MemOperand(output_array(), kPointerSize, PostIndex));
__ Sub(x11, x11, 2);
__ Cbnz(x11, &loop);
}
}
}
if (global()) {
Register success_counter = w0;
Register output_size = x10;
// Restart matching if the regular expression is flagged as global.
// Increment success counter.
__ Ldr(success_counter, MemOperand(frame_pointer(), kSuccessCounter));
__ Add(success_counter, success_counter, 1);
__ Str(success_counter, MemOperand(frame_pointer(), kSuccessCounter));
// Capture results have been stored, so the number of remaining global
// output registers is reduced by the number of stored captures.
__ Ldr(output_size, MemOperand(frame_pointer(), kOutputSize));
__ Sub(output_size, output_size, num_saved_registers_);
// Check whether we have enough room for another set of capture results.
__ Cmp(output_size, num_saved_registers_);
__ B(lt, &return_w0);
// The output pointer is already set to the next field in the output
// array.
// Update output size on the frame before we restart matching.
__ Str(output_size, MemOperand(frame_pointer(), kOutputSize));
if (global_with_zero_length_check()) {
// Special case for zero-length matches.
__ Cmp(current_input_offset(), first_capture_start);
// Not a zero-length match, restart.
__ B(ne, &load_char_start_regexp);
// Offset from the end is zero if we already reached the end.
__ Cbz(current_input_offset(), &return_w0);
// Advance current position after a zero-length match.
__ Add(current_input_offset(),
current_input_offset(),
Operand((mode_ == UC16) ? 2 : 1));
}
__ B(&load_char_start_regexp);
} else {
__ Mov(w0, SUCCESS);
}
}
if (exit_label_.is_linked()) {
// Exit and return w0
__ Bind(&exit_label_);
if (global()) {
__ Ldr(w0, MemOperand(frame_pointer(), kSuccessCounter));
}
}
__ Bind(&return_w0);
// Set stack pointer back to first register to retain
DCHECK(csp.Is(__ StackPointer()));
__ Mov(csp, fp);
__ AssertStackConsistency();
// Restore registers.
__ PopCPURegList(registers_to_retain);
__ Ret();
Label exit_with_exception;
// Registers x0 to x7 are used to store the first captures, they need to be
// retained over calls to C++ code.
CPURegList cached_registers(CPURegister::kRegister, kXRegSizeInBits, 0, 7);
DCHECK((cached_registers.Count() * 2) == kNumCachedRegisters);
if (check_preempt_label_.is_linked()) {
__ Bind(&check_preempt_label_);
SaveLinkRegister();
// The cached registers need to be retained.
__ PushCPURegList(cached_registers);
CallCheckStackGuardState(x10);
// Returning from the regexp code restores the stack (csp <- fp)
// so we don't need to drop the link register from it before exiting.
__ Cbnz(w0, &return_w0);
// Reset the cached registers.
__ PopCPURegList(cached_registers);
RestoreLinkRegister();
__ Ret();
}
if (stack_overflow_label_.is_linked()) {
__ Bind(&stack_overflow_label_);
SaveLinkRegister();
// The cached registers need to be retained.
__ PushCPURegList(cached_registers);
// Call GrowStack(backtrack_stackpointer(), &stack_base)
__ Mov(x2, ExternalReference::isolate_address(isolate()));
__ Add(x1, frame_pointer(), kStackBase);
__ Mov(x0, backtrack_stackpointer());
ExternalReference grow_stack =
ExternalReference::re_grow_stack(isolate());
__ CallCFunction(grow_stack, 3);
// If return NULL, we have failed to grow the stack, and
// must exit with a stack-overflow exception.
// Returning from the regexp code restores the stack (csp <- fp)
// so we don't need to drop the link register from it before exiting.
__ Cbz(w0, &exit_with_exception);
// Otherwise use return value as new stack pointer.
__ Mov(backtrack_stackpointer(), x0);
// Reset the cached registers.
__ PopCPURegList(cached_registers);
RestoreLinkRegister();
__ Ret();
}
if (exit_with_exception.is_linked()) {
__ Bind(&exit_with_exception);
__ Mov(w0, EXCEPTION);
__ B(&return_w0);
}
CodeDesc code_desc;
masm_->GetCode(&code_desc);
Handle<Code> code = isolate()->factory()->NewCode(
code_desc, Code::ComputeFlags(Code::REGEXP), masm_->CodeObject());
PROFILE(masm_->isolate(), RegExpCodeCreateEvent(*code, *source));
return Handle<HeapObject>::cast(code);
}
void RegExpMacroAssemblerARM64::GoTo(Label* to) {
BranchOrBacktrack(al, to);
}
void RegExpMacroAssemblerARM64::IfRegisterGE(int reg, int comparand,
Label* if_ge) {
Register to_compare = GetRegister(reg, w10);
CompareAndBranchOrBacktrack(to_compare, comparand, ge, if_ge);
}
void RegExpMacroAssemblerARM64::IfRegisterLT(int reg, int comparand,
Label* if_lt) {
Register to_compare = GetRegister(reg, w10);
CompareAndBranchOrBacktrack(to_compare, comparand, lt, if_lt);
}
void RegExpMacroAssemblerARM64::IfRegisterEqPos(int reg, Label* if_eq) {
Register to_compare = GetRegister(reg, w10);
__ Cmp(to_compare, current_input_offset());
BranchOrBacktrack(eq, if_eq);
}
RegExpMacroAssembler::IrregexpImplementation
RegExpMacroAssemblerARM64::Implementation() {
return kARM64Implementation;
}
void RegExpMacroAssemblerARM64::LoadCurrentCharacter(int cp_offset,
Label* on_end_of_input,
bool check_bounds,
int characters) {
// TODO(pielan): Make sure long strings are caught before this, and not
// just asserted in debug mode.
DCHECK(cp_offset >= -1); // ^ and \b can look behind one character.
// Be sane! (And ensure that an int32_t can be used to index the string)
DCHECK(cp_offset < (1<<30));
if (check_bounds) {
CheckPosition(cp_offset + characters - 1, on_end_of_input);
}
LoadCurrentCharacterUnchecked(cp_offset, characters);
}
void RegExpMacroAssemblerARM64::PopCurrentPosition() {
Pop(current_input_offset());
}
void RegExpMacroAssemblerARM64::PopRegister(int register_index) {
Pop(w10);
StoreRegister(register_index, w10);
}
void RegExpMacroAssemblerARM64::PushBacktrack(Label* label) {
if (label->is_bound()) {
int target = label->pos();
__ Mov(w10, target + Code::kHeaderSize - kHeapObjectTag);
} else {
__ Adr(x10, label, MacroAssembler::kAdrFar);
__ Sub(x10, x10, code_pointer());
if (masm_->emit_debug_code()) {
__ Cmp(x10, kWRegMask);
// The code offset has to fit in a W register.
__ Check(ls, kOffsetOutOfRange);
}
}
Push(w10);
CheckStackLimit();
}
void RegExpMacroAssemblerARM64::PushCurrentPosition() {
Push(current_input_offset());
}
void RegExpMacroAssemblerARM64::PushRegister(int register_index,
StackCheckFlag check_stack_limit) {
Register to_push = GetRegister(register_index, w10);
Push(to_push);
if (check_stack_limit) CheckStackLimit();
}
void RegExpMacroAssemblerARM64::ReadCurrentPositionFromRegister(int reg) {
Register cached_register;
RegisterState register_state = GetRegisterState(reg);
switch (register_state) {
case STACKED:
__ Ldr(current_input_offset(), register_location(reg));
break;
case CACHED_LSW:
cached_register = GetCachedRegister(reg);
__ Mov(current_input_offset(), cached_register.W());
break;
case CACHED_MSW:
cached_register = GetCachedRegister(reg);
__ Lsr(current_input_offset().X(), cached_register, kWRegSizeInBits);
break;
default:
UNREACHABLE();
break;
}
}
void RegExpMacroAssemblerARM64::ReadStackPointerFromRegister(int reg) {
Register read_from = GetRegister(reg, w10);
__ Ldr(x11, MemOperand(frame_pointer(), kStackBase));
__ Add(backtrack_stackpointer(), x11, Operand(read_from, SXTW));
}
void RegExpMacroAssemblerARM64::SetCurrentPositionFromEnd(int by) {
Label after_position;
__ Cmp(current_input_offset(), -by * char_size());
__ B(ge, &after_position);
__ Mov(current_input_offset(), -by * char_size());
// 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);
__ Bind(&after_position);
}
void RegExpMacroAssemblerARM64::SetRegister(int register_index, int to) {
DCHECK(register_index >= num_saved_registers_); // Reserved for positions!
Register set_to = wzr;
if (to != 0) {
set_to = w10;
__ Mov(set_to, to);
}
StoreRegister(register_index, set_to);
}
bool RegExpMacroAssemblerARM64::Succeed() {
__ B(&success_label_);
return global();
}
void RegExpMacroAssemblerARM64::WriteCurrentPositionToRegister(int reg,
int cp_offset) {
Register position = current_input_offset();
if (cp_offset != 0) {
position = w10;
__ Add(position, current_input_offset(), cp_offset * char_size());
}
StoreRegister(reg, position);
}
void RegExpMacroAssemblerARM64::ClearRegisters(int reg_from, int reg_to) {
DCHECK(reg_from <= reg_to);
int num_registers = reg_to - reg_from + 1;
// If the first capture register is cached in a hardware register but not
// aligned on a 64-bit one, we need to clear the first one specifically.
if ((reg_from < kNumCachedRegisters) && ((reg_from % 2) != 0)) {
StoreRegister(reg_from, non_position_value());
num_registers--;
reg_from++;
}
// Clear cached registers in pairs as far as possible.
while ((num_registers >= 2) && (reg_from < kNumCachedRegisters)) {
DCHECK(GetRegisterState(reg_from) == CACHED_LSW);
__ Mov(GetCachedRegister(reg_from), twice_non_position_value());
reg_from += 2;
num_registers -= 2;
}
if ((num_registers % 2) == 1) {
StoreRegister(reg_from, non_position_value());
num_registers--;
reg_from++;
}
if (num_registers > 0) {
// If there are some remaining registers, they are stored on the stack.
DCHECK(reg_from >= kNumCachedRegisters);
// Move down the indexes of the registers on stack to get the correct offset
// in memory.
reg_from -= kNumCachedRegisters;
reg_to -= kNumCachedRegisters;
// We should not unroll the loop for less than 2 registers.
STATIC_ASSERT(kNumRegistersToUnroll > 2);
// We position the base pointer to (reg_from + 1).
int base_offset = kFirstRegisterOnStack -
kWRegSize - (kWRegSize * reg_from);
if (num_registers > kNumRegistersToUnroll) {
Register base = x10;
__ Add(base, frame_pointer(), base_offset);
Label loop;
__ Mov(x11, num_registers);
__ Bind(&loop);
__ Str(twice_non_position_value(),
MemOperand(base, -kPointerSize, PostIndex));
__ Sub(x11, x11, 2);
__ Cbnz(x11, &loop);
} else {
for (int i = reg_from; i <= reg_to; i += 2) {
__ Str(twice_non_position_value(),
MemOperand(frame_pointer(), base_offset));
base_offset -= kWRegSize * 2;
}
}
}
}
void RegExpMacroAssemblerARM64::WriteStackPointerToRegister(int reg) {
__ Ldr(x10, MemOperand(frame_pointer(), kStackBase));
__ Sub(x10, backtrack_stackpointer(), x10);
if (masm_->emit_debug_code()) {
__ Cmp(x10, Operand(w10, SXTW));
// The stack offset needs to fit in a W register.
__ Check(eq, kOffsetOutOfRange);
}
StoreRegister(reg, w10);
}
// Helper function for reading a value out of a stack frame.
template <typename T>
static T& frame_entry(Address re_frame, int frame_offset) {
return *reinterpret_cast<T*>(re_frame + frame_offset);
}
int RegExpMacroAssemblerARM64::CheckStackGuardState(Address* return_address,
Code* re_code,
Address re_frame,
int start_offset,
const byte** input_start,
const byte** input_end) {
Isolate* isolate = frame_entry<Isolate*>(re_frame, kIsolate);
StackLimitCheck check(isolate);
if (check.JsHasOverflowed()) {
isolate->StackOverflow();
return EXCEPTION;
}
// If not real stack overflow the stack guard was used to interrupt
// execution for another purpose.
// If this is a direct call from JavaScript retry the RegExp forcing the call
// through the runtime system. Currently the direct call cannot handle a GC.
if (frame_entry<int>(re_frame, kDirectCall) == 1) {
return RETRY;
}
// Prepare for possible GC.
HandleScope handles(isolate);
Handle<Code> code_handle(re_code);
Handle<String> subject(frame_entry<String*>(re_frame, kInput));
// Current string.
bool is_ascii = subject->IsOneByteRepresentationUnderneath();
DCHECK(re_code->instruction_start() <= *return_address);
DCHECK(*return_address <=
re_code->instruction_start() + re_code->instruction_size());
Object* result = isolate->stack_guard()->HandleInterrupts();
if (*code_handle != re_code) { // Return address no longer valid
int delta = code_handle->address() - re_code->address();
// Overwrite the return address on the stack.
*return_address += delta;
}
if (result->IsException()) {
return EXCEPTION;
}
Handle<String> subject_tmp = subject;
int slice_offset = 0;
// Extract the underlying string and the slice offset.
if (StringShape(*subject_tmp).IsCons()) {
subject_tmp = Handle<String>(ConsString::cast(*subject_tmp)->first());
} else if (StringShape(*subject_tmp).IsSliced()) {
SlicedString* slice = SlicedString::cast(*subject_tmp);
subject_tmp = Handle<String>(slice->parent());
slice_offset = slice->offset();
}
// String might have changed.
if (subject_tmp->IsOneByteRepresentation() != is_ascii) {
// If we changed between an ASCII and an UC16 string, the specialized
// code cannot be used, and we need to restart regexp matching from
// scratch (including, potentially, compiling a new version of the code).
return RETRY;
}
// Otherwise, the content of the string might have moved. It must still
// be a sequential or external string with the same content.
// Update the start and end pointers in the stack frame to the current
// location (whether it has actually moved or not).
DCHECK(StringShape(*subject_tmp).IsSequential() ||
StringShape(*subject_tmp).IsExternal());
// The original start address of the characters to match.
const byte* start_address = *input_start;
// Find the current start address of the same character at the current string
// position.
const byte* new_address = StringCharacterPosition(*subject_tmp,
start_offset + slice_offset);
if (start_address != new_address) {
// If there is a difference, update the object pointer and start and end
// addresses in the RegExp stack frame to match the new value.
const byte* end_address = *input_end;
int byte_length = static_cast<int>(end_address - start_address);
frame_entry<const String*>(re_frame, kInput) = *subject;
*input_start = new_address;
*input_end = new_address + byte_length;
} else if (frame_entry<const String*>(re_frame, kInput) != *subject) {
// Subject string might have been a ConsString that underwent
// short-circuiting during GC. That will not change start_address but
// will change pointer inside the subject handle.
frame_entry<const String*>(re_frame, kInput) = *subject;
}
return 0;
}
void RegExpMacroAssemblerARM64::CheckPosition(int cp_offset,
Label* on_outside_input) {
CompareAndBranchOrBacktrack(current_input_offset(),
-cp_offset * char_size(),
ge,
on_outside_input);
}
bool RegExpMacroAssemblerARM64::CanReadUnaligned() {
// TODO(pielan): See whether or not we should disable unaligned accesses.
return !slow_safe();
}
// Private methods:
void RegExpMacroAssemblerARM64::CallCheckStackGuardState(Register scratch) {
// Allocate space on the stack to store the return address. The
// CheckStackGuardState C++ function will override it if the code
// moved. Allocate extra space for 2 arguments passed by pointers.
// AAPCS64 requires the stack to be 16 byte aligned.
int alignment = masm_->ActivationFrameAlignment();
DCHECK_EQ(alignment % 16, 0);
int align_mask = (alignment / kXRegSize) - 1;
int xreg_to_claim = (3 + align_mask) & ~align_mask;
DCHECK(csp.Is(__ StackPointer()));
__ Claim(xreg_to_claim);
// CheckStackGuardState needs the end and start addresses of the input string.
__ Poke(input_end(), 2 * kPointerSize);
__ Add(x5, csp, 2 * kPointerSize);
__ Poke(input_start(), kPointerSize);
__ Add(x4, csp, kPointerSize);
__ Mov(w3, start_offset());
// RegExp code frame pointer.
__ Mov(x2, frame_pointer());
// Code* of self.
__ Mov(x1, Operand(masm_->CodeObject()));
// We need to pass a pointer to the return address as first argument.
// The DirectCEntry stub will place the return address on the stack before
// calling so the stack pointer will point to it.
__ Mov(x0, csp);
ExternalReference check_stack_guard_state =
ExternalReference::re_check_stack_guard_state(isolate());
__ Mov(scratch, check_stack_guard_state);
DirectCEntryStub stub(isolate());
stub.GenerateCall(masm_, scratch);
// The input string may have been moved in memory, we need to reload it.
__ Peek(input_start(), kPointerSize);
__ Peek(input_end(), 2 * kPointerSize);
DCHECK(csp.Is(__ StackPointer()));
__ Drop(xreg_to_claim);
// Reload the Code pointer.
__ Mov(code_pointer(), Operand(masm_->CodeObject()));
}
void RegExpMacroAssemblerARM64::BranchOrBacktrack(Condition condition,
Label* to) {
if (condition == al) { // Unconditional.
if (to == NULL) {
Backtrack();
return;
}
__ B(to);
return;
}
if (to == NULL) {
to = &backtrack_label_;
}
__ B(condition, to);
}
void RegExpMacroAssemblerARM64::CompareAndBranchOrBacktrack(Register reg,
int immediate,
Condition condition,
Label* to) {
if ((immediate == 0) && ((condition == eq) || (condition == ne))) {
if (to == NULL) {
to = &backtrack_label_;
}
if (condition == eq) {
__ Cbz(reg, to);
} else {
__ Cbnz(reg, to);
}
} else {
__ Cmp(reg, immediate);
BranchOrBacktrack(condition, to);
}
}
void RegExpMacroAssemblerARM64::CheckPreemption() {
// Check for preemption.
ExternalReference stack_limit =
ExternalReference::address_of_stack_limit(isolate());
__ Mov(x10, stack_limit);
__ Ldr(x10, MemOperand(x10));
DCHECK(csp.Is(__ StackPointer()));
__ Cmp(csp, x10);
CallIf(&check_preempt_label_, ls);
}
void RegExpMacroAssemblerARM64::CheckStackLimit() {
ExternalReference stack_limit =
ExternalReference::address_of_regexp_stack_limit(isolate());
__ Mov(x10, stack_limit);
__ Ldr(x10, MemOperand(x10));
__ Cmp(backtrack_stackpointer(), x10);
CallIf(&stack_overflow_label_, ls);
}
void RegExpMacroAssemblerARM64::Push(Register source) {
DCHECK(source.Is32Bits());
DCHECK(!source.is(backtrack_stackpointer()));
__ Str(source,
MemOperand(backtrack_stackpointer(),
-static_cast<int>(kWRegSize),
PreIndex));
}
void RegExpMacroAssemblerARM64::Pop(Register target) {
DCHECK(target.Is32Bits());
DCHECK(!target.is(backtrack_stackpointer()));
__ Ldr(target,
MemOperand(backtrack_stackpointer(), kWRegSize, PostIndex));
}
Register RegExpMacroAssemblerARM64::GetCachedRegister(int register_index) {
DCHECK(register_index < kNumCachedRegisters);
return Register::Create(register_index / 2, kXRegSizeInBits);
}
Register RegExpMacroAssemblerARM64::GetRegister(int register_index,
Register maybe_result) {
DCHECK(maybe_result.Is32Bits());
DCHECK(register_index >= 0);
if (num_registers_ <= register_index) {
num_registers_ = register_index + 1;
}
Register result;
RegisterState register_state = GetRegisterState(register_index);
switch (register_state) {
case STACKED:
__ Ldr(maybe_result, register_location(register_index));
result = maybe_result;
break;
case CACHED_LSW:
result = GetCachedRegister(register_index).W();
break;
case CACHED_MSW:
__ Lsr(maybe_result.X(), GetCachedRegister(register_index),
kWRegSizeInBits);
result = maybe_result;
break;
default:
UNREACHABLE();
break;
}
DCHECK(result.Is32Bits());
return result;
}
void RegExpMacroAssemblerARM64::StoreRegister(int register_index,
Register source) {
DCHECK(source.Is32Bits());
DCHECK(register_index >= 0);
if (num_registers_ <= register_index) {
num_registers_ = register_index + 1;
}
Register cached_register;
RegisterState register_state = GetRegisterState(register_index);
switch (register_state) {
case STACKED:
__ Str(source, register_location(register_index));
break;
case CACHED_LSW:
cached_register = GetCachedRegister(register_index);
if (!source.Is(cached_register.W())) {
__ Bfi(cached_register, source.X(), 0, kWRegSizeInBits);
}
break;
case CACHED_MSW:
cached_register = GetCachedRegister(register_index);
__ Bfi(cached_register, source.X(), kWRegSizeInBits, kWRegSizeInBits);
break;
default:
UNREACHABLE();
break;
}
}
void RegExpMacroAssemblerARM64::CallIf(Label* to, Condition condition) {
Label skip_call;
if (condition != al) __ B(&skip_call, NegateCondition(condition));
__ Bl(to);
__ Bind(&skip_call);
}
void RegExpMacroAssemblerARM64::RestoreLinkRegister() {
DCHECK(csp.Is(__ StackPointer()));
__ Pop(lr, xzr);
__ Add(lr, lr, Operand(masm_->CodeObject()));
}
void RegExpMacroAssemblerARM64::SaveLinkRegister() {
DCHECK(csp.Is(__ StackPointer()));
__ Sub(lr, lr, Operand(masm_->CodeObject()));
__ Push(xzr, lr);
}
MemOperand RegExpMacroAssemblerARM64::register_location(int register_index) {
DCHECK(register_index < (1<<30));
DCHECK(register_index >= kNumCachedRegisters);
if (num_registers_ <= register_index) {
num_registers_ = register_index + 1;
}
register_index -= kNumCachedRegisters;
int offset = kFirstRegisterOnStack - register_index * kWRegSize;
return MemOperand(frame_pointer(), offset);
}
MemOperand RegExpMacroAssemblerARM64::capture_location(int register_index,
Register scratch) {
DCHECK(register_index < (1<<30));
DCHECK(register_index < num_saved_registers_);
DCHECK(register_index >= kNumCachedRegisters);
DCHECK_EQ(register_index % 2, 0);
register_index -= kNumCachedRegisters;
int offset = kFirstCaptureOnStack - register_index * kWRegSize;
// capture_location is used with Stp instructions to load/store 2 registers.
// The immediate field in the encoding is limited to 7 bits (signed).
if (is_int7(offset)) {
return MemOperand(frame_pointer(), offset);
} else {
__ Add(scratch, frame_pointer(), offset);
return MemOperand(scratch);
}
}
void RegExpMacroAssemblerARM64::LoadCurrentCharacterUnchecked(int cp_offset,
int characters) {
Register offset = current_input_offset();
// The ldr, str, ldrh, strh instructions can do unaligned accesses, if the CPU
// and the operating system running on the target allow it.
// If unaligned load/stores are not supported then this function must only
// be used to load a single character at a time.
// ARMv8 supports unaligned accesses but V8 or the kernel can decide to
// disable it.
// TODO(pielan): See whether or not we should disable unaligned accesses.
if (!CanReadUnaligned()) {
DCHECK(characters == 1);
}
if (cp_offset != 0) {
if (masm_->emit_debug_code()) {
__ Mov(x10, cp_offset * char_size());
__ Add(x10, x10, Operand(current_input_offset(), SXTW));
__ Cmp(x10, Operand(w10, SXTW));
// The offset needs to fit in a W register.
__ Check(eq, kOffsetOutOfRange);
} else {
__ Add(w10, current_input_offset(), cp_offset * char_size());
}
offset = w10;
}
if (mode_ == ASCII) {
if (characters == 4) {
__ Ldr(current_character(), MemOperand(input_end(), offset, SXTW));
} else if (characters == 2) {
__ Ldrh(current_character(), MemOperand(input_end(), offset, SXTW));
} else {
DCHECK(characters == 1);
__ Ldrb(current_character(), MemOperand(input_end(), offset, SXTW));
}
} else {
DCHECK(mode_ == UC16);
if (characters == 2) {
__ Ldr(current_character(), MemOperand(input_end(), offset, SXTW));
} else {
DCHECK(characters == 1);
__ Ldrh(current_character(), MemOperand(input_end(), offset, SXTW));
}
}
}
#endif // V8_INTERPRETED_REGEXP
}} // namespace v8::internal
#endif // V8_TARGET_ARCH_ARM64