deps/v8/src/ia32/regexp-macro-assembler-ia32.cc
// Copyright 2012 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_IA32
#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/ia32/regexp-macro-assembler-ia32.h"
namespace v8 {
namespace internal {
#ifndef V8_INTERPRETED_REGEXP
/*
* This assembler uses the following register assignment convention
* - edx : Current character. Must be loaded using LoadCurrentCharacter
* before using any of the dispatch methods. Temporarily stores the
* index of capture start after a matching pass for a global regexp.
* - edi : Current position in input, as negative offset from end of string.
* Please notice that this is the byte offset, not the character offset!
* - esi : end of input (points to byte after last character in input).
* - ebp : Frame pointer. Used to access arguments, local variables and
* RegExp registers.
* - esp : Points to tip of C stack.
* - ecx : Points to tip of backtrack stack
*
* The registers eax and ebx are free to use for computations.
*
* Each call to a public method should retain this convention.
* The stack will have the following structure:
* - Isolate* isolate (address of the current isolate)
* - direct_call (if 1, direct call from JavaScript code, if 0
* call through the runtime system)
* - stack_area_base (high end of the memory area to use as
* backtracking stack)
* - capture array size (may fit multiple sets of matches)
* - int* capture_array (int[num_saved_registers_], for output).
* - end of input (address of end of string)
* - start of input (address of first character in string)
* - start index (character index of start)
* - String* input_string (location of a handle containing the string)
* --- frame alignment (if applicable) ---
* - return address
* ebp-> - old ebp
* - backup of caller esi
* - backup of caller edi
* - backup of caller ebx
* - success counter (only for global regexps to count matches).
* - Offset of location before start of input (effectively character
* position -1). Used to initialize capture registers to a non-position.
* - register 0 ebp[-4] (only positions must be stored in the first
* - register 1 ebp[-8] num_saved_registers_ registers)
* - ...
*
* 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 starts out as garbage.
*
* The data up to the return address must be placed there by the calling
* code, by calling the code entry as cast to a function with the signature:
* int (*match)(String* input_string,
* int start_index,
* Address start,
* Address end,
* int* capture_output_array,
* bool at_start,
* byte* stack_area_base,
* bool direct_call)
*/
#define __ ACCESS_MASM(masm_)
RegExpMacroAssemblerIA32::RegExpMacroAssemblerIA32(
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_() {
DCHECK_EQ(0, registers_to_save % 2);
__ jmp(&entry_label_); // We'll write the entry code later.
__ bind(&start_label_); // And then continue from here.
}
RegExpMacroAssemblerIA32::~RegExpMacroAssemblerIA32() {
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 RegExpMacroAssemblerIA32::stack_limit_slack() {
return RegExpStack::kStackLimitSlack;
}
void RegExpMacroAssemblerIA32::AdvanceCurrentPosition(int by) {
if (by != 0) {
__ add(edi, Immediate(by * char_size()));
}
}
void RegExpMacroAssemblerIA32::AdvanceRegister(int reg, int by) {
DCHECK(reg >= 0);
DCHECK(reg < num_registers_);
if (by != 0) {
__ add(register_location(reg), Immediate(by));
}
}
void RegExpMacroAssemblerIA32::Backtrack() {
CheckPreemption();
// Pop Code* offset from backtrack stack, add Code* and jump to location.
Pop(ebx);
__ add(ebx, Immediate(masm_->CodeObject()));
__ jmp(ebx);
}
void RegExpMacroAssemblerIA32::Bind(Label* label) {
__ bind(label);
}
void RegExpMacroAssemblerIA32::CheckCharacter(uint32_t c, Label* on_equal) {
__ cmp(current_character(), c);
BranchOrBacktrack(equal, on_equal);
}
void RegExpMacroAssemblerIA32::CheckCharacterGT(uc16 limit, Label* on_greater) {
__ cmp(current_character(), limit);
BranchOrBacktrack(greater, on_greater);
}
void RegExpMacroAssemblerIA32::CheckAtStart(Label* on_at_start) {
Label not_at_start;
// Did we start the match at the start of the string at all?
__ cmp(Operand(ebp, kStartIndex), Immediate(0));
BranchOrBacktrack(not_equal, ¬_at_start);
// If we did, are we still at the start of the input?
__ lea(eax, Operand(esi, edi, times_1, 0));
__ cmp(eax, Operand(ebp, kInputStart));
BranchOrBacktrack(equal, on_at_start);
__ bind(¬_at_start);
}
void RegExpMacroAssemblerIA32::CheckNotAtStart(Label* on_not_at_start) {
// Did we start the match at the start of the string at all?
__ cmp(Operand(ebp, kStartIndex), Immediate(0));
BranchOrBacktrack(not_equal, on_not_at_start);
// If we did, are we still at the start of the input?
__ lea(eax, Operand(esi, edi, times_1, 0));
__ cmp(eax, Operand(ebp, kInputStart));
BranchOrBacktrack(not_equal, on_not_at_start);
}
void RegExpMacroAssemblerIA32::CheckCharacterLT(uc16 limit, Label* on_less) {
__ cmp(current_character(), limit);
BranchOrBacktrack(less, on_less);
}
void RegExpMacroAssemblerIA32::CheckGreedyLoop(Label* on_equal) {
Label fallthrough;
__ cmp(edi, Operand(backtrack_stackpointer(), 0));
__ j(not_equal, &fallthrough);
__ add(backtrack_stackpointer(), Immediate(kPointerSize)); // Pop.
BranchOrBacktrack(no_condition, on_equal);
__ bind(&fallthrough);
}
void RegExpMacroAssemblerIA32::CheckNotBackReferenceIgnoreCase(
int start_reg,
Label* on_no_match) {
Label fallthrough;
__ mov(edx, register_location(start_reg)); // Index of start of capture
__ mov(ebx, register_location(start_reg + 1)); // Index of end of capture
__ sub(ebx, edx); // Length of capture.
// The length of a capture should not be negative. This can only happen
// if the end of the capture is unrecorded, or at a point earlier than
// the start of the capture.
BranchOrBacktrack(less, on_no_match);
// If length is zero, either the capture is empty or it is completely
// uncaptured. In either case succeed immediately.
__ j(equal, &fallthrough);
// Check that there are sufficient characters left in the input.
__ mov(eax, edi);
__ add(eax, ebx);
BranchOrBacktrack(greater, on_no_match);
if (mode_ == ASCII) {
Label success;
Label fail;
Label loop_increment;
// Save register contents to make the registers available below.
__ push(edi);
__ push(backtrack_stackpointer());
// After this, the eax, ecx, and edi registers are available.
__ add(edx, esi); // Start of capture
__ add(edi, esi); // Start of text to match against capture.
__ add(ebx, edi); // End of text to match against capture.
Label loop;
__ bind(&loop);
__ movzx_b(eax, Operand(edi, 0));
__ cmpb_al(Operand(edx, 0));
__ j(equal, &loop_increment);
// Mismatch, try case-insensitive match (converting letters to lower-case).
__ or_(eax, 0x20); // Convert match character to lower-case.
__ lea(ecx, Operand(eax, -'a'));
__ cmp(ecx, static_cast<int32_t>('z' - 'a')); // Is eax a lowercase letter?
Label convert_capture;
__ j(below_equal, &convert_capture); // In range 'a'-'z'.
// Latin-1: Check for values in range [224,254] but not 247.
__ sub(ecx, Immediate(224 - 'a'));
__ cmp(ecx, Immediate(254 - 224));
__ j(above, &fail); // Weren't Latin-1 letters.
__ cmp(ecx, Immediate(247 - 224)); // Check for 247.
__ j(equal, &fail);
__ bind(&convert_capture);
// Also convert capture character.
__ movzx_b(ecx, Operand(edx, 0));
__ or_(ecx, 0x20);
__ cmp(eax, ecx);
__ j(not_equal, &fail);
__ bind(&loop_increment);
// Increment pointers into match and capture strings.
__ add(edx, Immediate(1));
__ add(edi, Immediate(1));
// Compare to end of match, and loop if not done.
__ cmp(edi, ebx);
__ j(below, &loop);
__ jmp(&success);
__ bind(&fail);
// Restore original values before failing.
__ pop(backtrack_stackpointer());
__ pop(edi);
BranchOrBacktrack(no_condition, on_no_match);
__ bind(&success);
// Restore original value before continuing.
__ pop(backtrack_stackpointer());
// Drop original value of character position.
__ add(esp, Immediate(kPointerSize));
// Compute new value of character position after the matched part.
__ sub(edi, esi);
} else {
DCHECK(mode_ == UC16);
// Save registers before calling C function.
__ push(esi);
__ push(edi);
__ push(backtrack_stackpointer());
__ push(ebx);
static const int argument_count = 4;
__ PrepareCallCFunction(argument_count, ecx);
// Put arguments into allocated stack area, last argument highest on stack.
// Parameters are
// Address byte_offset1 - Address captured substring's start.
// Address byte_offset2 - Address of current character position.
// size_t byte_length - length of capture in bytes(!)
// Isolate* isolate
// Set isolate.
__ mov(Operand(esp, 3 * kPointerSize),
Immediate(ExternalReference::isolate_address(isolate())));
// Set byte_length.
__ mov(Operand(esp, 2 * kPointerSize), ebx);
// Set byte_offset2.
// Found by adding negative string-end offset of current position (edi)
// to end of string.
__ add(edi, esi);
__ mov(Operand(esp, 1 * kPointerSize), edi);
// Set byte_offset1.
// Start of capture, where edx already holds string-end negative offset.
__ add(edx, esi);
__ mov(Operand(esp, 0 * kPointerSize), edx);
{
AllowExternalCallThatCantCauseGC scope(masm_);
ExternalReference compare =
ExternalReference::re_case_insensitive_compare_uc16(isolate());
__ CallCFunction(compare, argument_count);
}
// Pop original values before reacting on result value.
__ pop(ebx);
__ pop(backtrack_stackpointer());
__ pop(edi);
__ pop(esi);
// Check if function returned non-zero for success or zero for failure.
__ or_(eax, eax);
BranchOrBacktrack(zero, on_no_match);
// On success, increment position by length of capture.
__ add(edi, ebx);
}
__ bind(&fallthrough);
}
void RegExpMacroAssemblerIA32::CheckNotBackReference(
int start_reg,
Label* on_no_match) {
Label fallthrough;
Label success;
Label fail;
// Find length of back-referenced capture.
__ mov(edx, register_location(start_reg));
__ mov(eax, register_location(start_reg + 1));
__ sub(eax, edx); // Length to check.
// Fail on partial or illegal capture (start of capture after end of capture).
BranchOrBacktrack(less, on_no_match);
// Succeed on empty capture (including no capture)
__ j(equal, &fallthrough);
// Check that there are sufficient characters left in the input.
__ mov(ebx, edi);
__ add(ebx, eax);
BranchOrBacktrack(greater, on_no_match);
// Save register to make it available below.
__ push(backtrack_stackpointer());
// Compute pointers to match string and capture string
__ lea(ebx, Operand(esi, edi, times_1, 0)); // Start of match.
__ add(edx, esi); // Start of capture.
__ lea(ecx, Operand(eax, ebx, times_1, 0)); // End of match
Label loop;
__ bind(&loop);
if (mode_ == ASCII) {
__ movzx_b(eax, Operand(edx, 0));
__ cmpb_al(Operand(ebx, 0));
} else {
DCHECK(mode_ == UC16);
__ movzx_w(eax, Operand(edx, 0));
__ cmpw_ax(Operand(ebx, 0));
}
__ j(not_equal, &fail);
// Increment pointers into capture and match string.
__ add(edx, Immediate(char_size()));
__ add(ebx, Immediate(char_size()));
// Check if we have reached end of match area.
__ cmp(ebx, ecx);
__ j(below, &loop);
__ jmp(&success);
__ bind(&fail);
// Restore backtrack stackpointer.
__ pop(backtrack_stackpointer());
BranchOrBacktrack(no_condition, on_no_match);
__ bind(&success);
// Move current character position to position after match.
__ mov(edi, ecx);
__ sub(edi, esi);
// Restore backtrack stackpointer.
__ pop(backtrack_stackpointer());
__ bind(&fallthrough);
}
void RegExpMacroAssemblerIA32::CheckNotCharacter(uint32_t c,
Label* on_not_equal) {
__ cmp(current_character(), c);
BranchOrBacktrack(not_equal, on_not_equal);
}
void RegExpMacroAssemblerIA32::CheckCharacterAfterAnd(uint32_t c,
uint32_t mask,
Label* on_equal) {
if (c == 0) {
__ test(current_character(), Immediate(mask));
} else {
__ mov(eax, mask);
__ and_(eax, current_character());
__ cmp(eax, c);
}
BranchOrBacktrack(equal, on_equal);
}
void RegExpMacroAssemblerIA32::CheckNotCharacterAfterAnd(uint32_t c,
uint32_t mask,
Label* on_not_equal) {
if (c == 0) {
__ test(current_character(), Immediate(mask));
} else {
__ mov(eax, mask);
__ and_(eax, current_character());
__ cmp(eax, c);
}
BranchOrBacktrack(not_equal, on_not_equal);
}
void RegExpMacroAssemblerIA32::CheckNotCharacterAfterMinusAnd(
uc16 c,
uc16 minus,
uc16 mask,
Label* on_not_equal) {
DCHECK(minus < String::kMaxUtf16CodeUnit);
__ lea(eax, Operand(current_character(), -minus));
if (c == 0) {
__ test(eax, Immediate(mask));
} else {
__ and_(eax, mask);
__ cmp(eax, c);
}
BranchOrBacktrack(not_equal, on_not_equal);
}
void RegExpMacroAssemblerIA32::CheckCharacterInRange(
uc16 from,
uc16 to,
Label* on_in_range) {
__ lea(eax, Operand(current_character(), -from));
__ cmp(eax, to - from);
BranchOrBacktrack(below_equal, on_in_range);
}
void RegExpMacroAssemblerIA32::CheckCharacterNotInRange(
uc16 from,
uc16 to,
Label* on_not_in_range) {
__ lea(eax, Operand(current_character(), -from));
__ cmp(eax, to - from);
BranchOrBacktrack(above, on_not_in_range);
}
void RegExpMacroAssemblerIA32::CheckBitInTable(
Handle<ByteArray> table,
Label* on_bit_set) {
__ mov(eax, Immediate(table));
Register index = current_character();
if (mode_ != ASCII || kTableMask != String::kMaxOneByteCharCode) {
__ mov(ebx, kTableSize - 1);
__ and_(ebx, current_character());
index = ebx;
}
__ cmpb(FieldOperand(eax, index, times_1, ByteArray::kHeaderSize), 0);
BranchOrBacktrack(not_equal, on_bit_set);
}
bool RegExpMacroAssemblerIA32::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;
__ cmp(current_character(), ' ');
__ j(equal, &success, Label::kNear);
// Check range 0x09..0x0d
__ lea(eax, Operand(current_character(), -'\t'));
__ cmp(eax, '\r' - '\t');
__ j(below_equal, &success, Label::kNear);
// \u00a0 (NBSP).
__ cmp(eax, 0x00a0 - '\t');
BranchOrBacktrack(not_equal, 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')
__ lea(eax, Operand(current_character(), -'0'));
__ cmp(eax, '9' - '0');
BranchOrBacktrack(above, on_no_match);
return true;
case 'D':
// Match non ASCII-digits
__ lea(eax, Operand(current_character(), -'0'));
__ cmp(eax, '9' - '0');
BranchOrBacktrack(below_equal, on_no_match);
return true;
case '.': {
// Match non-newlines (not 0x0a('\n'), 0x0d('\r'), 0x2028 and 0x2029)
__ mov(eax, current_character());
__ xor_(eax, Immediate(0x01));
// See if current character is '\n'^1 or '\r'^1, i.e., 0x0b or 0x0c
__ sub(eax, Immediate(0x0b));
__ cmp(eax, 0x0c - 0x0b);
BranchOrBacktrack(below_equal, on_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.
__ sub(eax, Immediate(0x2028 - 0x0b));
__ cmp(eax, 0x2029 - 0x2028);
BranchOrBacktrack(below_equal, on_no_match);
}
return true;
}
case 'w': {
if (mode_ != ASCII) {
// Table is 128 entries, so all ASCII characters can be tested.
__ cmp(current_character(), Immediate('z'));
BranchOrBacktrack(above, on_no_match);
}
DCHECK_EQ(0, word_character_map[0]); // Character '\0' is not a word char.
ExternalReference word_map = ExternalReference::re_word_character_map();
__ test_b(current_character(),
Operand::StaticArray(current_character(), times_1, word_map));
BranchOrBacktrack(zero, 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(), Immediate('z'));
__ j(above, &done);
}
DCHECK_EQ(0, word_character_map[0]); // Character '\0' is not a word char.
ExternalReference word_map = ExternalReference::re_word_character_map();
__ test_b(current_character(),
Operand::StaticArray(current_character(), times_1, word_map));
BranchOrBacktrack(not_zero, on_no_match);
if (mode_ != ASCII) {
__ bind(&done);
}
return true;
}
// Non-standard classes (with no syntactic shorthand) used internally.
case '*':
// Match any character.
return true;
case 'n': {
// Match newlines (0x0a('\n'), 0x0d('\r'), 0x2028 or 0x2029).
// The opposite of '.'.
__ mov(eax, current_character());
__ xor_(eax, Immediate(0x01));
// See if current character is '\n'^1 or '\r'^1, i.e., 0x0b or 0x0c
__ sub(eax, Immediate(0x0b));
__ cmp(eax, 0x0c - 0x0b);
if (mode_ == ASCII) {
BranchOrBacktrack(above, on_no_match);
} else {
Label done;
BranchOrBacktrack(below_equal, &done);
DCHECK_EQ(UC16, mode_);
// Compare original value to 0x2028 and 0x2029, using the already
// computed (current_char ^ 0x01 - 0x0b). I.e., check for
// 0x201d (0x2028 - 0x0b) or 0x201e.
__ sub(eax, Immediate(0x2028 - 0x0b));
__ cmp(eax, 1);
BranchOrBacktrack(above, on_no_match);
__ bind(&done);
}
return true;
}
// No custom implementation (yet): s(UC16), S(UC16).
default:
return false;
}
}
void RegExpMacroAssemblerIA32::Fail() {
STATIC_ASSERT(FAILURE == 0); // Return value for failure is zero.
if (!global()) {
__ Move(eax, Immediate(FAILURE));
}
__ jmp(&exit_label_);
}
Handle<HeapObject> RegExpMacroAssemblerIA32::GetCode(Handle<String> source) {
Label return_eax;
// Finalize code - write the entry point code now we know how many
// registers we need.
// Entry code:
__ bind(&entry_label_);
// Tell the system that we have a stack frame. Because the type is MANUAL, no
// code is generated.
FrameScope scope(masm_, StackFrame::MANUAL);
// Actually emit code to start a new stack frame.
__ push(ebp);
__ mov(ebp, esp);
// Save callee-save registers. Order here should correspond to order of
// kBackup_ebx etc.
__ push(esi);
__ push(edi);
__ push(ebx); // Callee-save on MacOS.
__ push(Immediate(0)); // Number of successful matches in a global regexp.
__ push(Immediate(0)); // Make room for "input start - 1" constant.
// Check if we have space on the stack for registers.
Label stack_limit_hit;
Label stack_ok;
ExternalReference stack_limit =
ExternalReference::address_of_stack_limit(isolate());
__ mov(ecx, esp);
__ sub(ecx, Operand::StaticVariable(stack_limit));
// Handle it if the stack pointer is already below the stack limit.
__ j(below_equal, &stack_limit_hit);
// Check if there is room for the variable number of registers above
// the stack limit.
__ cmp(ecx, num_registers_ * kPointerSize);
__ j(above_equal, &stack_ok);
// Exit with OutOfMemory exception. There is not enough space on the stack
// for our working registers.
__ mov(eax, EXCEPTION);
__ jmp(&return_eax);
__ bind(&stack_limit_hit);
CallCheckStackGuardState(ebx);
__ or_(eax, eax);
// If returned value is non-zero, we exit with the returned value as result.
__ j(not_zero, &return_eax);
__ bind(&stack_ok);
// Load start index for later use.
__ mov(ebx, Operand(ebp, kStartIndex));
// Allocate space on stack for registers.
__ sub(esp, Immediate(num_registers_ * kPointerSize));
// Load string length.
__ mov(esi, Operand(ebp, kInputEnd));
// Load input position.
__ mov(edi, Operand(ebp, kInputStart));
// Set up edi to be negative offset from string end.
__ sub(edi, esi);
// Set eax to address of char before start of the string.
// (effectively string position -1).
__ neg(ebx);
if (mode_ == UC16) {
__ lea(eax, Operand(edi, ebx, times_2, -char_size()));
} else {
__ lea(eax, Operand(edi, ebx, times_1, -char_size()));
}
// Store this value in a local variable, for use when clearing
// position registers.
__ mov(Operand(ebp, kInputStartMinusOne), eax);
#if V8_OS_WIN
// Ensure that we write to each stack page, in order. Skipping a page
// on Windows can cause segmentation faults. Assuming page size is 4k.
const int kPageSize = 4096;
const int kRegistersPerPage = kPageSize / kPointerSize;
for (int i = num_saved_registers_ + kRegistersPerPage - 1;
i < num_registers_;
i += kRegistersPerPage) {
__ mov(register_location(i), eax); // One write every page.
}
#endif // V8_OS_WIN
Label load_char_start_regexp, start_regexp;
// Load newline if index is at start, previous character otherwise.
__ cmp(Operand(ebp, kStartIndex), Immediate(0));
__ j(not_equal, &load_char_start_regexp, Label::kNear);
__ mov(current_character(), '\n');
__ jmp(&start_regexp, Label::kNear);
// 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) { // Always is, if generated from a regexp.
// Fill saved registers with initial value = start offset - 1
// Fill in stack push order, to avoid accessing across an unwritten
// page (a problem on Windows).
if (num_saved_registers_ > 8) {
__ mov(ecx, kRegisterZero);
Label init_loop;
__ bind(&init_loop);
__ mov(Operand(ebp, ecx, times_1, 0), eax);
__ sub(ecx, Immediate(kPointerSize));
__ cmp(ecx, kRegisterZero - num_saved_registers_ * kPointerSize);
__ j(greater, &init_loop);
} else { // Unroll the loop.
for (int i = 0; i < num_saved_registers_; i++) {
__ mov(register_location(i), eax);
}
}
}
// Initialize backtrack stack pointer.
__ mov(backtrack_stackpointer(), Operand(ebp, kStackHighEnd));
__ jmp(&start_label_);
// Exit code:
if (success_label_.is_linked()) {
// Save captures when successful.
__ bind(&success_label_);
if (num_saved_registers_ > 0) {
// copy captures to output
__ mov(ebx, Operand(ebp, kRegisterOutput));
__ mov(ecx, Operand(ebp, kInputEnd));
__ mov(edx, Operand(ebp, kStartIndex));
__ sub(ecx, Operand(ebp, kInputStart));
if (mode_ == UC16) {
__ lea(ecx, Operand(ecx, edx, times_2, 0));
} else {
__ add(ecx, edx);
}
for (int i = 0; i < num_saved_registers_; i++) {
__ mov(eax, register_location(i));
if (i == 0 && global_with_zero_length_check()) {
// Keep capture start in edx for the zero-length check later.
__ mov(edx, eax);
}
// Convert to index from start of string, not end.
__ add(eax, ecx);
if (mode_ == UC16) {
__ sar(eax, 1); // Convert byte index to character index.
}
__ mov(Operand(ebx, i * kPointerSize), eax);
}
}
if (global()) {
// Restart matching if the regular expression is flagged as global.
// Increment success counter.
__ inc(Operand(ebp, kSuccessfulCaptures));
// Capture results have been stored, so the number of remaining global
// output registers is reduced by the number of stored captures.
__ mov(ecx, Operand(ebp, kNumOutputRegisters));
__ sub(ecx, Immediate(num_saved_registers_));
// Check whether we have enough room for another set of capture results.
__ cmp(ecx, Immediate(num_saved_registers_));
__ j(less, &exit_label_);
__ mov(Operand(ebp, kNumOutputRegisters), ecx);
// Advance the location for output.
__ add(Operand(ebp, kRegisterOutput),
Immediate(num_saved_registers_ * kPointerSize));
// Prepare eax to initialize registers with its value in the next run.
__ mov(eax, Operand(ebp, kInputStartMinusOne));
if (global_with_zero_length_check()) {
// Special case for zero-length matches.
// edx: capture start index
__ cmp(edi, edx);
// Not a zero-length match, restart.
__ j(not_equal, &load_char_start_regexp);
// edi (offset from the end) is zero if we already reached the end.
__ test(edi, edi);
__ j(zero, &exit_label_, Label::kNear);
// Advance current position after a zero-length match.
if (mode_ == UC16) {
__ add(edi, Immediate(2));
} else {
__ inc(edi);
}
}
__ jmp(&load_char_start_regexp);
} else {
__ mov(eax, Immediate(SUCCESS));
}
}
__ bind(&exit_label_);
if (global()) {
// Return the number of successful captures.
__ mov(eax, Operand(ebp, kSuccessfulCaptures));
}
__ bind(&return_eax);
// Skip esp past regexp registers.
__ lea(esp, Operand(ebp, kBackup_ebx));
// Restore callee-save registers.
__ pop(ebx);
__ pop(edi);
__ pop(esi);
// Exit function frame, restore previous one.
__ pop(ebp);
__ ret(0);
// Backtrack code (branch target for conditional backtracks).
if (backtrack_label_.is_linked()) {
__ bind(&backtrack_label_);
Backtrack();
}
Label exit_with_exception;
// Preempt-code
if (check_preempt_label_.is_linked()) {
SafeCallTarget(&check_preempt_label_);
__ push(backtrack_stackpointer());
__ push(edi);
CallCheckStackGuardState(ebx);
__ or_(eax, eax);
// If returning non-zero, we should end execution with the given
// result as return value.
__ j(not_zero, &return_eax);
__ pop(edi);
__ pop(backtrack_stackpointer());
// String might have moved: Reload esi from frame.
__ mov(esi, Operand(ebp, kInputEnd));
SafeReturn();
}
// Backtrack stack overflow code.
if (stack_overflow_label_.is_linked()) {
SafeCallTarget(&stack_overflow_label_);
// Reached if the backtrack-stack limit has been hit.
Label grow_failed;
// Save registers before calling C function
__ push(esi);
__ push(edi);
// Call GrowStack(backtrack_stackpointer())
static const int num_arguments = 3;
__ PrepareCallCFunction(num_arguments, ebx);
__ mov(Operand(esp, 2 * kPointerSize),
Immediate(ExternalReference::isolate_address(isolate())));
__ lea(eax, Operand(ebp, kStackHighEnd));
__ mov(Operand(esp, 1 * kPointerSize), eax);
__ mov(Operand(esp, 0 * kPointerSize), backtrack_stackpointer());
ExternalReference grow_stack =
ExternalReference::re_grow_stack(isolate());
__ CallCFunction(grow_stack, num_arguments);
// If return NULL, we have failed to grow the stack, and
// must exit with a stack-overflow exception.
__ or_(eax, eax);
__ j(equal, &exit_with_exception);
// Otherwise use return value as new stack pointer.
__ mov(backtrack_stackpointer(), eax);
// Restore saved registers and continue.
__ pop(edi);
__ pop(esi);
SafeReturn();
}
if (exit_with_exception.is_linked()) {
// If any of the code above needed to exit with an exception.
__ bind(&exit_with_exception);
// Exit with Result EXCEPTION(-1) to signal thrown exception.
__ mov(eax, EXCEPTION);
__ jmp(&return_eax);
}
CodeDesc code_desc;
masm_->GetCode(&code_desc);
Handle<Code> code =
isolate()->factory()->NewCode(code_desc,
Code::ComputeFlags(Code::REGEXP),
masm_->CodeObject());
PROFILE(isolate(), RegExpCodeCreateEvent(*code, *source));
return Handle<HeapObject>::cast(code);
}
void RegExpMacroAssemblerIA32::GoTo(Label* to) {
BranchOrBacktrack(no_condition, to);
}
void RegExpMacroAssemblerIA32::IfRegisterGE(int reg,
int comparand,
Label* if_ge) {
__ cmp(register_location(reg), Immediate(comparand));
BranchOrBacktrack(greater_equal, if_ge);
}
void RegExpMacroAssemblerIA32::IfRegisterLT(int reg,
int comparand,
Label* if_lt) {
__ cmp(register_location(reg), Immediate(comparand));
BranchOrBacktrack(less, if_lt);
}
void RegExpMacroAssemblerIA32::IfRegisterEqPos(int reg,
Label* if_eq) {
__ cmp(edi, register_location(reg));
BranchOrBacktrack(equal, if_eq);
}
RegExpMacroAssembler::IrregexpImplementation
RegExpMacroAssemblerIA32::Implementation() {
return kIA32Implementation;
}
void RegExpMacroAssemblerIA32::LoadCurrentCharacter(int cp_offset,
Label* on_end_of_input,
bool check_bounds,
int characters) {
DCHECK(cp_offset >= -1); // ^ and \b can look behind one character.
DCHECK(cp_offset < (1<<30)); // Be sane! (And ensure negation works)
if (check_bounds) {
CheckPosition(cp_offset + characters - 1, on_end_of_input);
}
LoadCurrentCharacterUnchecked(cp_offset, characters);
}
void RegExpMacroAssemblerIA32::PopCurrentPosition() {
Pop(edi);
}
void RegExpMacroAssemblerIA32::PopRegister(int register_index) {
Pop(eax);
__ mov(register_location(register_index), eax);
}
void RegExpMacroAssemblerIA32::PushBacktrack(Label* label) {
Push(Immediate::CodeRelativeOffset(label));
CheckStackLimit();
}
void RegExpMacroAssemblerIA32::PushCurrentPosition() {
Push(edi);
}
void RegExpMacroAssemblerIA32::PushRegister(int register_index,
StackCheckFlag check_stack_limit) {
__ mov(eax, register_location(register_index));
Push(eax);
if (check_stack_limit) CheckStackLimit();
}
void RegExpMacroAssemblerIA32::ReadCurrentPositionFromRegister(int reg) {
__ mov(edi, register_location(reg));
}
void RegExpMacroAssemblerIA32::ReadStackPointerFromRegister(int reg) {
__ mov(backtrack_stackpointer(), register_location(reg));
__ add(backtrack_stackpointer(), Operand(ebp, kStackHighEnd));
}
void RegExpMacroAssemblerIA32::SetCurrentPositionFromEnd(int by) {
Label after_position;
__ cmp(edi, -by * char_size());
__ j(greater_equal, &after_position, Label::kNear);
__ mov(edi, -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 RegExpMacroAssemblerIA32::SetRegister(int register_index, int to) {
DCHECK(register_index >= num_saved_registers_); // Reserved for positions!
__ mov(register_location(register_index), Immediate(to));
}
bool RegExpMacroAssemblerIA32::Succeed() {
__ jmp(&success_label_);
return global();
}
void RegExpMacroAssemblerIA32::WriteCurrentPositionToRegister(int reg,
int cp_offset) {
if (cp_offset == 0) {
__ mov(register_location(reg), edi);
} else {
__ lea(eax, Operand(edi, cp_offset * char_size()));
__ mov(register_location(reg), eax);
}
}
void RegExpMacroAssemblerIA32::ClearRegisters(int reg_from, int reg_to) {
DCHECK(reg_from <= reg_to);
__ mov(eax, Operand(ebp, kInputStartMinusOne));
for (int reg = reg_from; reg <= reg_to; reg++) {
__ mov(register_location(reg), eax);
}
}
void RegExpMacroAssemblerIA32::WriteStackPointerToRegister(int reg) {
__ mov(eax, backtrack_stackpointer());
__ sub(eax, Operand(ebp, kStackHighEnd));
__ mov(register_location(reg), eax);
}
// Private methods:
void RegExpMacroAssemblerIA32::CallCheckStackGuardState(Register scratch) {
static const int num_arguments = 3;
__ PrepareCallCFunction(num_arguments, scratch);
// RegExp code frame pointer.
__ mov(Operand(esp, 2 * kPointerSize), ebp);
// Code* of self.
__ mov(Operand(esp, 1 * kPointerSize), Immediate(masm_->CodeObject()));
// Next address on the stack (will be address of return address).
__ lea(eax, Operand(esp, -kPointerSize));
__ mov(Operand(esp, 0 * kPointerSize), eax);
ExternalReference check_stack_guard =
ExternalReference::re_check_stack_guard_state(isolate());
__ CallCFunction(check_stack_guard, num_arguments);
}
// 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&>(Memory::int32_at(re_frame + frame_offset));
}
int RegExpMacroAssemblerIA32::CheckStackGuardState(Address* return_address,
Code* re_code,
Address re_frame) {
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, kInputString));
// 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 = frame_entry<const byte*>(re_frame, kInputStart);
// Find the current start address of the same character at the current string
// position.
int start_index = frame_entry<int>(re_frame, kStartIndex);
const byte* new_address = StringCharacterPosition(*subject_tmp,
start_index + 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 = frame_entry<const byte* >(re_frame, kInputEnd);
int byte_length = static_cast<int>(end_address - start_address);
frame_entry<const String*>(re_frame, kInputString) = *subject;
frame_entry<const byte*>(re_frame, kInputStart) = new_address;
frame_entry<const byte*>(re_frame, kInputEnd) = new_address + byte_length;
} else if (frame_entry<const String*>(re_frame, kInputString) != *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, kInputString) = *subject;
}
return 0;
}
Operand RegExpMacroAssemblerIA32::register_location(int register_index) {
DCHECK(register_index < (1<<30));
if (num_registers_ <= register_index) {
num_registers_ = register_index + 1;
}
return Operand(ebp, kRegisterZero - register_index * kPointerSize);
}
void RegExpMacroAssemblerIA32::CheckPosition(int cp_offset,
Label* on_outside_input) {
__ cmp(edi, -cp_offset * char_size());
BranchOrBacktrack(greater_equal, on_outside_input);
}
void RegExpMacroAssemblerIA32::BranchOrBacktrack(Condition condition,
Label* to) {
if (condition < 0) { // No condition
if (to == NULL) {
Backtrack();
return;
}
__ jmp(to);
return;
}
if (to == NULL) {
__ j(condition, &backtrack_label_);
return;
}
__ j(condition, to);
}
void RegExpMacroAssemblerIA32::SafeCall(Label* to) {
Label return_to;
__ push(Immediate::CodeRelativeOffset(&return_to));
__ jmp(to);
__ bind(&return_to);
}
void RegExpMacroAssemblerIA32::SafeReturn() {
__ pop(ebx);
__ add(ebx, Immediate(masm_->CodeObject()));
__ jmp(ebx);
}
void RegExpMacroAssemblerIA32::SafeCallTarget(Label* name) {
__ bind(name);
}
void RegExpMacroAssemblerIA32::Push(Register source) {
DCHECK(!source.is(backtrack_stackpointer()));
// Notice: This updates flags, unlike normal Push.
__ sub(backtrack_stackpointer(), Immediate(kPointerSize));
__ mov(Operand(backtrack_stackpointer(), 0), source);
}
void RegExpMacroAssemblerIA32::Push(Immediate value) {
// Notice: This updates flags, unlike normal Push.
__ sub(backtrack_stackpointer(), Immediate(kPointerSize));
__ mov(Operand(backtrack_stackpointer(), 0), value);
}
void RegExpMacroAssemblerIA32::Pop(Register target) {
DCHECK(!target.is(backtrack_stackpointer()));
__ mov(target, Operand(backtrack_stackpointer(), 0));
// Notice: This updates flags, unlike normal Pop.
__ add(backtrack_stackpointer(), Immediate(kPointerSize));
}
void RegExpMacroAssemblerIA32::CheckPreemption() {
// Check for preemption.
Label no_preempt;
ExternalReference stack_limit =
ExternalReference::address_of_stack_limit(isolate());
__ cmp(esp, Operand::StaticVariable(stack_limit));
__ j(above, &no_preempt);
SafeCall(&check_preempt_label_);
__ bind(&no_preempt);
}
void RegExpMacroAssemblerIA32::CheckStackLimit() {
Label no_stack_overflow;
ExternalReference stack_limit =
ExternalReference::address_of_regexp_stack_limit(isolate());
__ cmp(backtrack_stackpointer(), Operand::StaticVariable(stack_limit));
__ j(above, &no_stack_overflow);
SafeCall(&stack_overflow_label_);
__ bind(&no_stack_overflow);
}
void RegExpMacroAssemblerIA32::LoadCurrentCharacterUnchecked(int cp_offset,
int characters) {
if (mode_ == ASCII) {
if (characters == 4) {
__ mov(current_character(), Operand(esi, edi, times_1, cp_offset));
} else if (characters == 2) {
__ movzx_w(current_character(), Operand(esi, edi, times_1, cp_offset));
} else {
DCHECK(characters == 1);
__ movzx_b(current_character(), Operand(esi, edi, times_1, cp_offset));
}
} else {
DCHECK(mode_ == UC16);
if (characters == 2) {
__ mov(current_character(),
Operand(esi, edi, times_1, cp_offset * sizeof(uc16)));
} else {
DCHECK(characters == 1);
__ movzx_w(current_character(),
Operand(esi, edi, times_1, cp_offset * sizeof(uc16)));
}
}
}
#undef __
#endif // V8_INTERPRETED_REGEXP
}} // namespace v8::internal
#endif // V8_TARGET_ARCH_IA32