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// Copyright 2008-2009 the V8 project authors. All rights reserved.
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are
// met:
//
// * Redistributions of source code must retain the above copyright
// notice, this list of conditions and the following disclaimer.
// * Redistributions in binary form must reproduce the above
// copyright notice, this list of conditions and the following
// disclaimer in the documentation and/or other materials provided
// with the distribution.
// * Neither the name of Google Inc. nor the names of its
// contributors may be used to endorse or promote products derived
// from this software without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
#include "v8.h"
#include "unicode.h"
#include "log.h"
#include "ast.h"
#include "regexp-stack.h"
#include "macro-assembler.h"
#include "regexp-macro-assembler.h"
#include "ia32/macro-assembler-ia32.h"
#include "ia32/regexp-macro-assembler-ia32.h"
namespace v8 {
namespace internal {
/*
* This assembler uses the following register assignment convention
* - edx : current character. Must be loaded using LoadCurrentCharacter
* before using any of the dispatch methods.
* - 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, ebx and ecx are free to use for computations.
*
* Each call to a public method should retain this convention.
* The stack will have the following structure:
* - stack_area_top (High end of the memory area to use as
* backtracking stack)
* - at_start (if 1, start at start of string, if 0, don't)
* - 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)
* - void* 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
* - 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, e.g., by calling the code entry as cast to:
* int (*match)(String* input_string,
* Address start,
* Address end,
* int* capture_output_array,
* bool at_start,
* byte* stack_area_top)
*/
#define __ ACCESS_MASM(masm_)
RegExpMacroAssemblerIA32::RegExpMacroAssemblerIA32(
Mode mode,
int registers_to_save)
: masm_(new MacroAssembler(NULL, kRegExpCodeSize)),
constants_(kRegExpConstantsSize),
mode_(mode),
num_registers_(registers_to_save),
num_saved_registers_(registers_to_save),
entry_label_(),
start_label_(),
success_label_(),
backtrack_label_(),
exit_label_() {
__ 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) {
Label inside_string;
__ add(Operand(edi), Immediate(by * char_size()));
}
}
void RegExpMacroAssemblerIA32::AdvanceRegister(int reg, int by) {
ASSERT(reg >= 0);
ASSERT(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(Operand(ebx), Immediate(masm_->CodeObject()));
__ jmp(Operand(ebx));
}
void RegExpMacroAssemblerIA32::Bind(Label* label) {
__ bind(label);
}
void RegExpMacroAssemblerIA32::CheckBitmap(uc16 start,
Label* bitmap,
Label* on_zero) {
UNIMPLEMENTED();
}
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, kAtStart), Immediate(0));
BranchOrBacktrack(equal, &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(equal, on_at_start);
__ bind(&not_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, kAtStart), Immediate(0));
BranchOrBacktrack(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::CheckCharacters(Vector<const uc16> str,
int cp_offset,
Label* on_failure,
bool check_end_of_string) {
int byte_length = str.length() * char_size();
int byte_offset = cp_offset * char_size();
if (check_end_of_string) {
// Check that there are at least str.length() characters left in the input.
__ cmp(Operand(edi), Immediate(-(byte_offset + byte_length)));
BranchOrBacktrack(greater, on_failure);
}
Label backtrack;
if (on_failure == NULL) {
// Avoid inlining the Backtrack macro for each test.
Label skip_backtrack;
__ jmp(&skip_backtrack);
__ bind(&backtrack);
Backtrack();
__ bind(&skip_backtrack);
on_failure = &backtrack;
}
for (int i = 0; i < str.length(); i++) {
if (mode_ == ASCII) {
__ cmpb(Operand(esi, edi, times_1, byte_offset + i),
static_cast<int8_t>(str[i]));
} else {
ASSERT(mode_ == UC16);
__ cmpw(Operand(esi, edi, times_1, byte_offset + i * sizeof(uc16)),
Immediate(str[i]));
}
BranchOrBacktrack(not_equal, on_failure);
}
}
void RegExpMacroAssemblerIA32::CheckGreedyLoop(Label* on_equal) {
Label fallthrough;
__ cmp(edi, Operand(backtrack_stackpointer(), 0));
__ j(not_equal, &fallthrough);
__ add(Operand(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, Operand(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, not_taken);
// If length is zero, either the capture is empty or it is completely
// uncaptured. In either case succeed immediately.
__ j(equal, &fallthrough);
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, Operand(esi)); // Start of capture
__ add(edi, Operand(esi)); // Start of text to match against capture.
__ add(ebx, Operand(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?
__ j(above, &fail);
// Also convert capture character.
__ movzx_b(ecx, Operand(edx, 0));
__ or_(ecx, 0x20);
__ cmp(eax, Operand(ecx));
__ j(not_equal, &fail);
__ bind(&loop_increment);
// Increment pointers into match and capture strings.
__ add(Operand(edx), Immediate(1));
__ add(Operand(edi), Immediate(1));
// Compare to end of match, and loop if not done.
__ cmp(edi, Operand(ebx));
__ j(below, &loop, taken);
__ 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(Operand(esp), Immediate(kPointerSize));
// Compute new value of character position after the matched part.
__ sub(edi, Operand(esi));
} else {
ASSERT(mode_ == UC16);
// Save registers before calling C function.
__ push(esi);
__ push(edi);
__ push(backtrack_stackpointer());
__ push(ebx);
const int argument_count = 3;
FrameAlign(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(!)
// 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, Operand(esi));
__ mov(Operand(esp, 1 * kPointerSize), edi);
// Set byte_offset1.
// Start of capture, where edx already holds string-end negative offset.
__ add(edx, Operand(esi));
__ mov(Operand(esp, 0 * kPointerSize), edx);
Address function_address = FUNCTION_ADDR(&CaseInsensitiveCompareUC16);
CallCFunction(function_address, 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, Operand(eax));
BranchOrBacktrack(zero, on_no_match);
// On success, increment position by length of capture.
__ add(edi, Operand(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, Operand(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, Operand(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, Operand(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 {
ASSERT(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(Operand(edx), Immediate(char_size()));
__ add(Operand(ebx), Immediate(char_size()));
// Check if we have reached end of match area.
__ cmp(ebx, Operand(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(Operand(edi), esi);
// Restore backtrack stackpointer.
__ pop(backtrack_stackpointer());
__ bind(&fallthrough);
}
void RegExpMacroAssemblerIA32::CheckNotRegistersEqual(int reg1,
int reg2,
Label* on_not_equal) {
__ mov(eax, register_location(reg1));
__ cmp(eax, register_location(reg2));
BranchOrBacktrack(not_equal, on_not_equal);
}
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) {
__ mov(eax, current_character());
__ and_(eax, mask);
__ cmp(eax, c);
BranchOrBacktrack(equal, on_equal);
}
void RegExpMacroAssemblerIA32::CheckNotCharacterAfterAnd(uint32_t c,
uint32_t mask,
Label* on_not_equal) {
__ mov(eax, current_character());
__ and_(eax, mask);
__ cmp(eax, c);
BranchOrBacktrack(not_equal, on_not_equal);
}
void RegExpMacroAssemblerIA32::CheckNotCharacterAfterMinusAnd(
uc16 c,
uc16 minus,
uc16 mask,
Label* on_not_equal) {
ASSERT(minus < String::kMaxUC16CharCode);
__ lea(eax, Operand(current_character(), -minus));
__ and_(eax, mask);
__ cmp(eax, c);
BranchOrBacktrack(not_equal, on_not_equal);
}
bool RegExpMacroAssemblerIA32::CheckSpecialCharacterClass(uc16 type,
int cp_offset,
bool check_offset,
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) {
// ASCII space characters are '\t'..'\r' and ' '.
if (check_offset) {
LoadCurrentCharacter(cp_offset, on_no_match);
} else {
LoadCurrentCharacterUnchecked(cp_offset, 1);
}
Label success;
__ cmp(current_character(), ' ');
__ j(equal, &success);
// Check range 0x09..0x0d
__ sub(Operand(current_character()), Immediate('\t'));
__ cmp(current_character(), '\r' - '\t');
BranchOrBacktrack(above, on_no_match);
__ bind(&success);
return true;
}
return false;
case 'S':
// Match non-space characters.
if (check_offset) {
LoadCurrentCharacter(cp_offset, on_no_match, 1);
} else {
LoadCurrentCharacterUnchecked(cp_offset, 1);
}
if (mode_ == ASCII) {
// ASCII space characters are '\t'..'\r' and ' '.
__ cmp(current_character(), ' ');
BranchOrBacktrack(equal, on_no_match);
__ sub(Operand(current_character()), Immediate('\t'));
__ cmp(current_character(), '\r' - '\t');
BranchOrBacktrack(below_equal, on_no_match);
return true;
}
return false;
case 'd':
// Match ASCII digits ('0'..'9')
if (check_offset) {
LoadCurrentCharacter(cp_offset, on_no_match, 1);
} else {
LoadCurrentCharacterUnchecked(cp_offset, 1);
}
__ sub(Operand(current_character()), Immediate('0'));
__ cmp(current_character(), '9' - '0');
BranchOrBacktrack(above, on_no_match);
return true;
case 'D':
// Match non ASCII-digits
if (check_offset) {
LoadCurrentCharacter(cp_offset, on_no_match, 1);
} else {
LoadCurrentCharacterUnchecked(cp_offset, 1);
}
__ sub(Operand(current_character()), Immediate('0'));
__ cmp(current_character(), '9' - '0');
BranchOrBacktrack(below_equal, on_no_match);
return true;
case '.': {
// Match non-newlines (not 0x0a('\n'), 0x0d('\r'), 0x2028 and 0x2029)
if (check_offset) {
LoadCurrentCharacter(cp_offset, on_no_match, 1);
} else {
LoadCurrentCharacterUnchecked(cp_offset, 1);
}
__ xor_(Operand(current_character()), Immediate(0x01));
// See if current character is '\n'^1 or '\r'^1, i.e., 0x0b or 0x0c
__ sub(Operand(current_character()), Immediate(0x0b));
__ cmp(current_character(), 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(Operand(current_character()), Immediate(0x2028 - 0x0b));
__ cmp(current_character(), 1);
BranchOrBacktrack(below_equal, on_no_match);
}
return true;
}
case '*':
// Match any character.
if (check_offset) {
CheckPosition(cp_offset, on_no_match);
}
return true;
// No custom implementation (yet): w, W, s(UC16), S(UC16).
default:
return false;
}
}
void RegExpMacroAssemblerIA32::DispatchHalfNibbleMap(
uc16 start,
Label* half_nibble_map,
const Vector<Label*>& destinations) {
UNIMPLEMENTED();
}
void RegExpMacroAssemblerIA32::DispatchByteMap(
uc16 start,
Label* byte_map,
const Vector<Label*>& destinations) {
UNIMPLEMENTED();
}
void RegExpMacroAssemblerIA32::DispatchHighByteMap(
byte start,
Label* byte_map,
const Vector<Label*>& destinations) {
UNIMPLEMENTED();
}
void RegExpMacroAssemblerIA32::EmitOrLink(Label* label) {
UNIMPLEMENTED(); // Has no use.
}
void RegExpMacroAssemblerIA32::Fail() {
ASSERT(FAILURE == 0); // Return value for failure is zero.
__ xor_(eax, Operand(eax)); // zero eax.
__ jmp(&exit_label_);
}
Handle<Object> RegExpMacroAssemblerIA32::GetCode(Handle<String> source) {
// Finalize code - write the entry point code now we know how many
// registers we need.
// Entry code:
__ bind(&entry_label_);
// Start 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)); // Make room for "input start - 1" constant.
// Check if we have space on the stack for registers.
Label retry_stack_check;
Label stack_limit_hit;
Label stack_ok;
__ bind(&retry_stack_check);
ExternalReference stack_guard_limit =
ExternalReference::address_of_stack_guard_limit();
__ mov(ecx, esp);
__ sub(ecx, Operand::StaticVariable(stack_guard_limit));
// Handle it if the stack pointer is already below the stack limit.
__ j(below_equal, &stack_limit_hit, not_taken);
// 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, taken);
// Exit with OutOfMemory exception. There is not enough space on the stack
// for our working registers.
__ mov(eax, EXCEPTION);
__ jmp(&exit_label_);
__ bind(&stack_limit_hit);
CallCheckStackGuardState(ebx);
__ or_(eax, Operand(eax));
// If returned value is non-zero, we exit with the returned value as result.
// Otherwise it was a preemption and we just check the limit again.
__ j(equal, &retry_stack_check);
// Return value was non-zero. Exit with exception or retry.
__ jmp(&exit_label_);
__ bind(&stack_ok);
// Allocate space on stack for registers.
__ sub(Operand(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, Operand(esi));
if (num_saved_registers_ > 0) {
// 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).
__ mov(ecx, kRegisterZero);
// Set eax to address of char before start of input
// (effectively string position -1).
__ lea(eax, Operand(edi, -char_size()));
// Store this value in a local variable, for use when clearing
// position registers.
__ mov(Operand(ebp, kInputStartMinusOne), eax);
Label init_loop;
__ bind(&init_loop);
__ mov(Operand(ebp, ecx, times_1, +0), eax);
__ sub(Operand(ecx), Immediate(kPointerSize));
__ cmp(ecx, kRegisterZero - num_saved_registers_ * kPointerSize);
__ j(greater, &init_loop);
}
// Ensure that we have written 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.
}
// Initialize backtrack stack pointer.
__ mov(backtrack_stackpointer(), Operand(ebp, kStackHighEnd));
// Load previous char as initial value of current-character.
Label at_start;
__ cmp(Operand(ebp, kAtStart), Immediate(0));
__ j(not_equal, &at_start);
LoadCurrentCharacterUnchecked(-1, 1); // Load previous char.
__ jmp(&start_label_);
__ bind(&at_start);
__ mov(current_character(), '\n');
__ 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));
__ sub(ecx, Operand(ebp, kInputStart));
for (int i = 0; i < num_saved_registers_; i++) {
__ mov(eax, register_location(i));
__ add(eax, Operand(ecx)); // Convert to index from start, not end.
if (mode_ == UC16) {
__ sar(eax, 1); // Convert byte index to character index.
}
__ mov(Operand(ebx, i * kPointerSize), eax);
}
}
__ mov(eax, Immediate(SUCCESS));
}
// Exit and return eax
__ bind(&exit_label_);
// 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()) {
__ bind(&check_preempt_label_);
__ push(backtrack_stackpointer());
__ push(edi);
Label retry;
__ bind(&retry);
CallCheckStackGuardState(ebx);
__ or_(eax, Operand(eax));
// If returning non-zero, we should end execution with the given
// result as return value.
__ j(not_zero, &exit_label_);
// Check if we are still preempted.
ExternalReference stack_guard_limit =
ExternalReference::address_of_stack_guard_limit();
__ cmp(esp, Operand::StaticVariable(stack_guard_limit));
__ j(below_equal, &retry);
__ 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()) {
__ bind(&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())
int num_arguments = 2;
FrameAlign(num_arguments, ebx);
__ lea(eax, Operand(ebp, kStackHighEnd));
__ mov(Operand(esp, 1 * kPointerSize), eax);
__ mov(Operand(esp, 0 * kPointerSize), backtrack_stackpointer());
CallCFunction(FUNCTION_ADDR(&GrowStack), num_arguments);
// If return NULL, we have failed to grow the stack, and
// must exit with a stack-overflow exception.
__ or_(eax, Operand(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(&exit_label_);
}
CodeDesc code_desc;
masm_->GetCode(&code_desc);
Handle<Code> code = Factory::NewCode(code_desc,
NULL,
Code::ComputeFlags(Code::REGEXP),
masm_->CodeObject());
LOG(RegExpCodeCreateEvent(*code, *source));
return Handle<Object>::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) {
ASSERT(cp_offset >= -1); // ^ and \b can look behind one character.
ASSERT(cp_offset < (1<<30)); // Be sane! (And ensure negation works)
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::SetRegister(int register_index, int to) {
ASSERT(register_index >= num_saved_registers_); // Reserved for positions!
__ mov(register_location(register_index), Immediate(to));
}
void RegExpMacroAssemblerIA32::Succeed() {
__ jmp(&success_label_);
}
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) {
ASSERT(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);
}
RegExpMacroAssemblerIA32::Result RegExpMacroAssemblerIA32::Match(
Handle<Code> regexp_code,
Handle<String> subject,
int* offsets_vector,
int offsets_vector_length,
int previous_index) {
ASSERT(subject->IsFlat());
ASSERT(previous_index >= 0);
ASSERT(previous_index <= subject->length());
// No allocations before calling the regexp, but we can't use
// AssertNoAllocation, since regexps might be preempted, and another thread
// might do allocation anyway.
String* subject_ptr = *subject;
// Character offsets into string.
int start_offset = previous_index;
int end_offset = subject_ptr->length();
bool is_ascii = subject->IsAsciiRepresentation();
if (StringShape(subject_ptr).IsCons()) {
subject_ptr = ConsString::cast(subject_ptr)->first();
} else if (StringShape(subject_ptr).IsSliced()) {
SlicedString* slice = SlicedString::cast(subject_ptr);
start_offset += slice->start();
end_offset += slice->start();
subject_ptr = slice->buffer();
}
// Ensure that an underlying string has the same ascii-ness.
ASSERT(subject_ptr->IsAsciiRepresentation() == is_ascii);
ASSERT(subject_ptr->IsExternalString() || subject_ptr->IsSeqString());
// String is now either Sequential or External
int char_size_shift = is_ascii ? 0 : 1;
int char_length = end_offset - start_offset;
const byte* input_start =
StringCharacterPosition(subject_ptr, start_offset);
int byte_length = char_length << char_size_shift;
const byte* input_end = input_start + byte_length;
RegExpMacroAssemblerIA32::Result res = Execute(*regexp_code,
subject_ptr,
start_offset,
input_start,
input_end,
offsets_vector,
previous_index == 0);
if (res == SUCCESS) {
// Capture values are relative to start_offset only.
// Convert them to be relative to start of string.
for (int i = 0; i < offsets_vector_length; i++) {
if (offsets_vector[i] >= 0) {
offsets_vector[i] += previous_index;
}
}
}
return res;
}
// Private methods:
static unibrow::Mapping<unibrow::Ecma262Canonicalize> canonicalize;
RegExpMacroAssemblerIA32::Result RegExpMacroAssemblerIA32::Execute(
Code* code,
String* input,
int start_offset,
const byte* input_start,
const byte* input_end,
int* output,
bool at_start) {
typedef int (*matcher)(String*, int, const byte*,
const byte*, int*, int, Address);
matcher matcher_func = FUNCTION_CAST<matcher>(code->entry());
int at_start_val = at_start ? 1 : 0;
// Ensure that the minimum stack has been allocated.
RegExpStack stack;
Address stack_top = RegExpStack::stack_top();
int result = matcher_func(input,
start_offset,
input_start,
input_end,
output,
at_start_val,
stack_top);
ASSERT(result <= SUCCESS);
ASSERT(result >= RETRY);
if (result == EXCEPTION && !Top::has_pending_exception()) {
// We detected a stack overflow (on the backtrack stack) in RegExp code,
// but haven't created the exception yet.
Top::StackOverflow();
}
return static_cast<Result>(result);
}
int RegExpMacroAssemblerIA32::CaseInsensitiveCompareUC16(Address byte_offset1,
Address byte_offset2,
size_t byte_length) {
// This function is not allowed to cause a garbage collection.
// A GC might move the calling generated code and invalidate the
// return address on the stack.
ASSERT(byte_length % 2 == 0);
uc16* substring1 = reinterpret_cast<uc16*>(byte_offset1);
uc16* substring2 = reinterpret_cast<uc16*>(byte_offset2);
size_t length = byte_length >> 1;
for (size_t i = 0; i < length; i++) {
unibrow::uchar c1 = substring1[i];
unibrow::uchar c2 = substring2[i];
if (c1 != c2) {
canonicalize.get(c1, '\0', &c1);
if (c1 != c2) {
canonicalize.get(c2, '\0', &c2);
if (c1 != c2) {
return 0;
}
}
}
}
return 1;
}
void RegExpMacroAssemblerIA32::CallCheckStackGuardState(Register scratch) {
int num_arguments = 3;
FrameAlign(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);
CallCFunction(FUNCTION_ADDR(&CheckStackGuardState), 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));
}
const byte* RegExpMacroAssemblerIA32::StringCharacterPosition(String* subject,
int start_index) {
// Not just flat, but ultra flat.
ASSERT(subject->IsExternalString() || subject->IsSeqString());
ASSERT(start_index >= 0);
ASSERT(start_index <= subject->length());
if (subject->IsAsciiRepresentation()) {
const byte* address;
if (StringShape(subject).IsExternal()) {
const char* data = ExternalAsciiString::cast(subject)->resource()->data();
address = reinterpret_cast<const byte*>(data);
} else {
ASSERT(subject->IsSeqAsciiString());
char* data = SeqAsciiString::cast(subject)->GetChars();
address = reinterpret_cast<const byte*>(data);
}
return address + start_index;
}
const uc16* data;
if (StringShape(subject).IsExternal()) {
data = ExternalTwoByteString::cast(subject)->resource()->data();
} else {
ASSERT(subject->IsSeqTwoByteString());
data = SeqTwoByteString::cast(subject)->GetChars();
}
return reinterpret_cast<const byte*>(data + start_index);
}
int RegExpMacroAssemblerIA32::CheckStackGuardState(Address* return_address,
Code* re_code,
Address re_frame) {
if (StackGuard::IsStackOverflow()) {
Top::StackOverflow();
return EXCEPTION;
}
// If not real stack overflow the stack guard was used to interrupt
// execution for another purpose.
// Prepare for possible GC.
HandleScope handles;
Handle<Code> code_handle(re_code);
Handle<String> subject(frame_entry<String*>(re_frame, kInputString));
// Current string.
bool is_ascii = subject->IsAsciiRepresentation();
ASSERT(re_code->instruction_start() <= *return_address);
ASSERT(*return_address <=
re_code->instruction_start() + re_code->instruction_size());
Object* result = Execution::HandleStackGuardInterrupt();
if (*code_handle != re_code) { // Return address no longer valid
int delta = *code_handle - re_code;
// Overwrite the return address on the stack.
*return_address += delta;
}
if (result->IsException()) {
return EXCEPTION;
}
// String might have changed.
if (subject->IsAsciiRepresentation() != 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).
ASSERT(StringShape(*subject).IsSequential() ||
StringShape(*subject).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, start_index);
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 = 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;
}
return 0;
}
Address RegExpMacroAssemblerIA32::GrowStack(Address stack_pointer,
Address* stack_top) {
size_t size = RegExpStack::stack_capacity();
Address old_stack_top = RegExpStack::stack_top();
ASSERT(old_stack_top == *stack_top);
ASSERT(stack_pointer <= old_stack_top);
ASSERT(static_cast<size_t>(old_stack_top - stack_pointer) <= size);
Address new_stack_top = RegExpStack::EnsureCapacity(size * 2);
if (new_stack_top == NULL) {
return NULL;
}
*stack_top = new_stack_top;
return new_stack_top - (old_stack_top - stack_pointer);
}
Operand RegExpMacroAssemblerIA32::register_location(int register_index) {
ASSERT(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,
Hint hint) {
if (condition < 0) { // No condition
if (to == NULL) {
Backtrack();
return;
}
__ jmp(to);
return;
}
if (to == NULL) {
__ j(condition, &backtrack_label_, hint);
return;
}
__ j(condition, to, hint);
}
void RegExpMacroAssemblerIA32::SafeCall(Label* to) {
Label return_to;
__ push(Immediate::CodeRelativeOffset(&return_to));
__ jmp(to);
__ bind(&return_to);
}
void RegExpMacroAssemblerIA32::SafeReturn() {
__ pop(ebx);
__ add(Operand(ebx), Immediate(masm_->CodeObject()));
__ jmp(Operand(ebx));
}
void RegExpMacroAssemblerIA32::Push(Register source) {
ASSERT(!source.is(backtrack_stackpointer()));
// Notice: This updates flags, unlike normal Push.
__ sub(Operand(backtrack_stackpointer()), Immediate(kPointerSize));
__ mov(Operand(backtrack_stackpointer(), 0), source);
}
void RegExpMacroAssemblerIA32::Push(Immediate value) {
// Notice: This updates flags, unlike normal Push.
__ sub(Operand(backtrack_stackpointer()), Immediate(kPointerSize));
__ mov(Operand(backtrack_stackpointer(), 0), value);
}
void RegExpMacroAssemblerIA32::Pop(Register target) {
ASSERT(!target.is(backtrack_stackpointer()));
__ mov(target, Operand(backtrack_stackpointer(), 0));
// Notice: This updates flags, unlike normal Pop.
__ add(Operand(backtrack_stackpointer()), Immediate(kPointerSize));
}
void RegExpMacroAssemblerIA32::CheckPreemption() {
// Check for preemption.
Label no_preempt;
ExternalReference stack_guard_limit =
ExternalReference::address_of_stack_guard_limit();
__ cmp(esp, Operand::StaticVariable(stack_guard_limit));
__ j(above, &no_preempt, taken);
SafeCall(&check_preempt_label_);
__ bind(&no_preempt);
}
void RegExpMacroAssemblerIA32::CheckStackLimit() {
if (FLAG_check_stack) {
Label no_stack_overflow;
ExternalReference stack_limit =
ExternalReference::address_of_regexp_stack_limit();
__ cmp(backtrack_stackpointer(), Operand::StaticVariable(stack_limit));
__ j(above, &no_stack_overflow);
SafeCall(&stack_overflow_label_);
__ bind(&no_stack_overflow);
}
}
void RegExpMacroAssemblerIA32::FrameAlign(int num_arguments, Register scratch) {
// TODO(lrn): Since we no longer use the system stack arbitrarily (but we do
// use it, e.g., for SafeCall), we know the number of elements on the stack
// since the last frame alignment. We might be able to do this simpler then.
int frameAlignment = OS::ActivationFrameAlignment();
if (frameAlignment != 0) {
// Make stack end at alignment and make room for num_arguments words
// and the original value of esp.
__ mov(scratch, esp);
__ sub(Operand(esp), Immediate((num_arguments + 1) * kPointerSize));
ASSERT(IsPowerOf2(frameAlignment));
__ and_(esp, -frameAlignment);
__ mov(Operand(esp, num_arguments * kPointerSize), scratch);
} else {
__ sub(Operand(esp), Immediate(num_arguments * kPointerSize));
}
}
void RegExpMacroAssemblerIA32::CallCFunction(Address function_address,
int num_arguments) {
__ mov(Operand(eax), Immediate(reinterpret_cast<int32_t>(function_address)));
__ call(Operand(eax));
if (OS::ActivationFrameAlignment() != 0) {
__ mov(esp, Operand(esp, num_arguments * kPointerSize));
} else {
__ add(Operand(esp), Immediate(num_arguments * sizeof(int32_t)));
}
}
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 {
ASSERT(characters == 1);
__ movzx_b(current_character(), Operand(esi, edi, times_1, cp_offset));
}
} else {
ASSERT(mode_ == UC16);
if (characters == 2) {
__ mov(current_character(),
Operand(esi, edi, times_1, cp_offset * sizeof(uc16)));
} else {
ASSERT(characters == 1);
__ movzx_w(current_character(),
Operand(esi, edi, times_1, cp_offset * sizeof(uc16)));
}
}
}
void RegExpMacroAssemblerIA32::LoadConstantBufferAddress(Register reg,
ArraySlice* buffer) {
__ mov(reg, buffer->array());
__ add(Operand(reg), Immediate(buffer->base_offset()));
}
#undef __
}} // namespace v8::internal