// Copyright 2011 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"
#if defined(V8_TARGET_ARCH_X64)
#include "serialize.h"
#include "unicode.h"
#include "log.h"
#include "regexp-stack.h"
#include "macro-assembler.h"
#include "regexp-macro-assembler.h"
#include "x64/regexp-macro-assembler-x64.h"
namespace v8 {
namespace internal {
#ifndef V8_INTERPRETED_REGEXP
/*
* This assembler uses the following register assignment convention
* - rdx : currently loaded character(s) as ASCII or UC16. Must be loaded using
* LoadCurrentCharacter before using any of the dispatch methods.
* - rdi : current position in input, as negative offset from end of string.
* Please notice that this is the byte offset, not the character
* offset! Is always a 32-bit signed (negative) offset, but must be
* maintained sign-extended to 64 bits, since it is used as index.
* - rsi : end of input (points to byte after last character in input),
* so that rsi+rdi points to the current character.
* - rbp : frame pointer. Used to access arguments, local variables and
* RegExp registers.
* - rsp : points to tip of C stack.
* - rcx : points to tip of backtrack stack. The backtrack stack contains
* only 32-bit values. Most are offsets from some base (e.g., character
* positions from end of string or code location from Code* pointer).
* - r8 : code object pointer. Used to convert between absolute and
* code-object-relative addresses.
*
* The registers rax, rbx, r9 and r11 are free to use for computations.
* If changed to use r12+, they should be saved as callee-save registers.
* The macro assembler special registers r12 and r13 (kSmiConstantRegister,
* kRootRegister) aren't special during execution of RegExp code (they don't
* hold the values assumed when creating JS code), so no Smi or Root related
* macro operations can be used.
*
* Each call to a C++ method should retain these registers.
*
* The stack will have the following content, in some order, indexable from the
* frame pointer (see, e.g., kStackHighEnd):
* - 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)
* - 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 (input string)
* - return address
* - backup of callee save registers (rbx, possibly rsi and rdi).
* - Offset of location before start of input (effectively character
* position -1). Used to initialize capture registers to a non-position.
* - At start of string (if 1, we are starting at the start of the
* string, otherwise 0)
* - register 0 rbp[-n] (Only positions must be stored in the first
* - register 1 rbp[-n-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 uninitialized.
*
* The first seven values must be provided by the calling code by
* calling the code's entry address cast to a function pointer with the
* following 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_))
RegExpMacroAssemblerX64::RegExpMacroAssemblerX64(
Mode mode,
int registers_to_save)
: masm_(Isolate::Current(), NULL, kRegExpCodeSize),
no_root_array_scope_(&masm_),
code_relative_fixup_positions_(4),
mode_(mode),
num_registers_(registers_to_save),
num_saved_registers_(registers_to_save),
entry_label_(),
start_label_(),
success_label_(),
backtrack_label_(),
exit_label_() {
ASSERT_EQ(0, registers_to_save % 2);
__ jmp(&entry_label_); // We'll write the entry code when we know more.
__ bind(&start_label_); // And then continue from here.
}
RegExpMacroAssemblerX64::~RegExpMacroAssemblerX64() {
// 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 RegExpMacroAssemblerX64::stack_limit_slack() {
return RegExpStack::kStackLimitSlack;
}
void RegExpMacroAssemblerX64::AdvanceCurrentPosition(int by) {
if (by != 0) {
__ addq(rdi, Immediate(by * char_size()));
}
}
void RegExpMacroAssemblerX64::AdvanceRegister(int reg, int by) {
ASSERT(reg >= 0);
ASSERT(reg < num_registers_);
if (by != 0) {
__ addq(register_location(reg), Immediate(by));
}
}
void RegExpMacroAssemblerX64::Backtrack() {
CheckPreemption();
// Pop Code* offset from backtrack stack, add Code* and jump to location.
Pop(rbx);
__ addq(rbx, code_object_pointer());
__ jmp(rbx);
}
void RegExpMacroAssemblerX64::Bind(Label* label) {
__ bind(label);
}
void RegExpMacroAssemblerX64::CheckCharacter(uint32_t c, Label* on_equal) {
__ cmpl(current_character(), Immediate(c));
BranchOrBacktrack(equal, on_equal);
}
void RegExpMacroAssemblerX64::CheckCharacterGT(uc16 limit, Label* on_greater) {
__ cmpl(current_character(), Immediate(limit));
BranchOrBacktrack(greater, on_greater);
}
void RegExpMacroAssemblerX64::CheckAtStart(Label* on_at_start) {
Label not_at_start;
// Did we start the match at the start of the string at all?
__ cmpl(Operand(rbp, kStartIndex), Immediate(0));
BranchOrBacktrack(not_equal, ¬_at_start);
// If we did, are we still at the start of the input?
__ lea(rax, Operand(rsi, rdi, times_1, 0));
__ cmpq(rax, Operand(rbp, kInputStart));
BranchOrBacktrack(equal, on_at_start);
__ bind(¬_at_start);
}
void RegExpMacroAssemblerX64::CheckNotAtStart(Label* on_not_at_start) {
// Did we start the match at the start of the string at all?
__ cmpl(Operand(rbp, kStartIndex), Immediate(0));
BranchOrBacktrack(not_equal, on_not_at_start);
// If we did, are we still at the start of the input?
__ lea(rax, Operand(rsi, rdi, times_1, 0));
__ cmpq(rax, Operand(rbp, kInputStart));
BranchOrBacktrack(not_equal, on_not_at_start);
}
void RegExpMacroAssemblerX64::CheckCharacterLT(uc16 limit, Label* on_less) {
__ cmpl(current_character(), Immediate(limit));
BranchOrBacktrack(less, on_less);
}
void RegExpMacroAssemblerX64::CheckCharacters(Vector<const uc16> str,
int cp_offset,
Label* on_failure,
bool check_end_of_string) {
#ifdef DEBUG
// If input is ASCII, don't even bother calling here if the string to
// match contains a non-ASCII character.
if (mode_ == ASCII) {
ASSERT(String::IsAscii(str.start(), str.length()));
}
#endif
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.
__ cmpl(rdi, Immediate(-(byte_offset + byte_length)));
BranchOrBacktrack(greater, on_failure);
}
if (on_failure == NULL) {
// Instead of inlining a backtrack, (re)use the global backtrack target.
on_failure = &backtrack_label_;
}
// Do one character test first to minimize loading for the case that
// we don't match at all (loading more than one character introduces that
// chance of reading unaligned and reading across cache boundaries).
// If the first character matches, expect a larger chance of matching the
// string, and start loading more characters at a time.
if (mode_ == ASCII) {
__ cmpb(Operand(rsi, rdi, times_1, byte_offset),
Immediate(static_cast<int8_t>(str[0])));
} else {
// Don't use 16-bit immediate. The size changing prefix throws off
// pre-decoding.
__ movzxwl(rax,
Operand(rsi, rdi, times_1, byte_offset));
__ cmpl(rax, Immediate(static_cast<int32_t>(str[0])));
}
BranchOrBacktrack(not_equal, on_failure);
__ lea(rbx, Operand(rsi, rdi, times_1, 0));
for (int i = 1, n = str.length(); i < n; ) {
if (mode_ == ASCII) {
if (i + 8 <= n) {
uint64_t combined_chars =
(static_cast<uint64_t>(str[i + 0]) << 0) ||
(static_cast<uint64_t>(str[i + 1]) << 8) ||
(static_cast<uint64_t>(str[i + 2]) << 16) ||
(static_cast<uint64_t>(str[i + 3]) << 24) ||
(static_cast<uint64_t>(str[i + 4]) << 32) ||
(static_cast<uint64_t>(str[i + 5]) << 40) ||
(static_cast<uint64_t>(str[i + 6]) << 48) ||
(static_cast<uint64_t>(str[i + 7]) << 56);
__ movq(rax, combined_chars, RelocInfo::NONE);
__ cmpq(rax, Operand(rbx, byte_offset + i));
i += 8;
} else if (i + 4 <= n) {
uint32_t combined_chars =
(static_cast<uint32_t>(str[i + 0]) << 0) ||
(static_cast<uint32_t>(str[i + 1]) << 8) ||
(static_cast<uint32_t>(str[i + 2]) << 16) ||
(static_cast<uint32_t>(str[i + 3]) << 24);
__ cmpl(Operand(rbx, byte_offset + i), Immediate(combined_chars));
i += 4;
} else {
__ cmpb(Operand(rbx, byte_offset + i),
Immediate(static_cast<int8_t>(str[i])));
i++;
}
} else {
ASSERT(mode_ == UC16);
if (i + 4 <= n) {
uint64_t combined_chars = *reinterpret_cast<const uint64_t*>(&str[i]);
__ movq(rax, combined_chars, RelocInfo::NONE);
__ cmpq(rax,
Operand(rsi, rdi, times_1, byte_offset + i * sizeof(uc16)));
i += 4;
} else if (i + 2 <= n) {
uint32_t combined_chars = *reinterpret_cast<const uint32_t*>(&str[i]);
__ cmpl(Operand(rsi, rdi, times_1, byte_offset + i * sizeof(uc16)),
Immediate(combined_chars));
i += 2;
} else {
__ movzxwl(rax,
Operand(rsi, rdi, times_1, byte_offset + i * sizeof(uc16)));
__ cmpl(rax, Immediate(str[i]));
i++;
}
}
BranchOrBacktrack(not_equal, on_failure);
}
}
void RegExpMacroAssemblerX64::CheckGreedyLoop(Label* on_equal) {
Label fallthrough;
__ cmpl(rdi, Operand(backtrack_stackpointer(), 0));
__ j(not_equal, &fallthrough);
Drop();
BranchOrBacktrack(no_condition, on_equal);
__ bind(&fallthrough);
}
void RegExpMacroAssemblerX64::CheckNotBackReferenceIgnoreCase(
int start_reg,
Label* on_no_match) {
Label fallthrough;
__ movq(rdx, register_location(start_reg)); // Offset of start of capture
__ movq(rbx, register_location(start_reg + 1)); // Offset of end of capture
__ subq(rbx, rdx); // Length of capture.
// -----------------------
// rdx = Start offset of capture.
// rbx = Length of capture
// If length is negative, this code will fail (it's a symptom of a partial or
// illegal capture where start of capture after end of capture).
// This must not happen (no back-reference can reference a capture that wasn't
// closed before in the reg-exp, and we must not generate code that can cause
// this condition).
// If length is zero, either the capture is empty or it is nonparticipating.
// In either case succeed immediately.
__ j(equal, &fallthrough);
if (mode_ == ASCII) {
Label loop_increment;
if (on_no_match == NULL) {
on_no_match = &backtrack_label_;
}
__ lea(r9, Operand(rsi, rdx, times_1, 0));
__ lea(r11, Operand(rsi, rdi, times_1, 0));
__ addq(rbx, r9); // End of capture
// ---------------------
// r11 - current input character address
// r9 - current capture character address
// rbx - end of capture
Label loop;
__ bind(&loop);
__ movzxbl(rdx, Operand(r9, 0));
__ movzxbl(rax, Operand(r11, 0));
// al - input character
// dl - capture character
__ cmpb(rax, rdx);
__ j(equal, &loop_increment);
// Mismatch, try case-insensitive match (converting letters to lower-case).
// I.e., if or-ing with 0x20 makes values equal and in range 'a'-'z', it's
// a match.
__ or_(rax, Immediate(0x20)); // Convert match character to lower-case.
__ or_(rdx, Immediate(0x20)); // Convert capture character to lower-case.
__ cmpb(rax, rdx);
__ j(not_equal, on_no_match); // Definitely not equal.
__ subb(rax, Immediate('a'));
__ cmpb(rax, Immediate('z' - 'a'));
__ j(above, on_no_match); // Weren't letters anyway.
__ bind(&loop_increment);
// Increment pointers into match and capture strings.
__ addq(r11, Immediate(1));
__ addq(r9, Immediate(1));
// Compare to end of capture, and loop if not done.
__ cmpq(r9, rbx);
__ j(below, &loop);
// Compute new value of character position after the matched part.
__ movq(rdi, r11);
__ subq(rdi, rsi);
} else {
ASSERT(mode_ == UC16);
// Save important/volatile registers before calling C function.
#ifndef _WIN64
// Caller save on Linux and callee save in Windows.
__ push(rsi);
__ push(rdi);
#endif
__ push(backtrack_stackpointer());
static const int num_arguments = 4;
__ PrepareCallCFunction(num_arguments);
// Put arguments into parameter registers. 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
#ifdef _WIN64
// Compute and set byte_offset1 (start of capture).
__ lea(rcx, Operand(rsi, rdx, times_1, 0));
// Set byte_offset2.
__ lea(rdx, Operand(rsi, rdi, times_1, 0));
// Set byte_length.
__ movq(r8, rbx);
// Isolate.
__ LoadAddress(r9, ExternalReference::isolate_address());
#else // AMD64 calling convention
// Compute byte_offset2 (current position = rsi+rdi).
__ lea(rax, Operand(rsi, rdi, times_1, 0));
// Compute and set byte_offset1 (start of capture).
__ lea(rdi, Operand(rsi, rdx, times_1, 0));
// Set byte_offset2.
__ movq(rsi, rax);
// Set byte_length.
__ movq(rdx, rbx);
// Isolate.
__ LoadAddress(rcx, ExternalReference::isolate_address());
#endif
{ // NOLINT: Can't find a way to open this scope without confusing the
// linter.
AllowExternalCallThatCantCauseGC scope(&masm_);
ExternalReference compare =
ExternalReference::re_case_insensitive_compare_uc16(masm_.isolate());
__ CallCFunction(compare, num_arguments);
}
// Restore original values before reacting on result value.
__ Move(code_object_pointer(), masm_.CodeObject());
__ pop(backtrack_stackpointer());
#ifndef _WIN64
__ pop(rdi);
__ pop(rsi);
#endif
// Check if function returned non-zero for success or zero for failure.
__ testq(rax, rax);
BranchOrBacktrack(zero, on_no_match);
// On success, increment position by length of capture.
// Requires that rbx is callee save (true for both Win64 and AMD64 ABIs).
__ addq(rdi, rbx);
}
__ bind(&fallthrough);
}
void RegExpMacroAssemblerX64::CheckNotBackReference(
int start_reg,
Label* on_no_match) {
Label fallthrough;
// Find length of back-referenced capture.
__ movq(rdx, register_location(start_reg));
__ movq(rax, register_location(start_reg + 1));
__ subq(rax, rdx); // Length to check.
// Fail on partial or illegal capture (start of capture after end of capture).
// This must not happen (no back-reference can reference a capture that wasn't
// closed before in the reg-exp).
__ Check(greater_equal, "Invalid capture referenced");
// Succeed on empty capture (including non-participating capture)
__ j(equal, &fallthrough);
// -----------------------
// rdx - Start of capture
// rax - length of capture
// Check that there are sufficient characters left in the input.
__ movl(rbx, rdi);
__ addl(rbx, rax);
BranchOrBacktrack(greater, on_no_match);
// Compute pointers to match string and capture string
__ lea(rbx, Operand(rsi, rdi, times_1, 0)); // Start of match.
__ addq(rdx, rsi); // Start of capture.
__ lea(r9, Operand(rdx, rax, times_1, 0)); // End of capture
// -----------------------
// rbx - current capture character address.
// rbx - current input character address .
// r9 - end of input to match (capture length after rbx).
Label loop;
__ bind(&loop);
if (mode_ == ASCII) {
__ movzxbl(rax, Operand(rdx, 0));
__ cmpb(rax, Operand(rbx, 0));
} else {
ASSERT(mode_ == UC16);
__ movzxwl(rax, Operand(rdx, 0));
__ cmpw(rax, Operand(rbx, 0));
}
BranchOrBacktrack(not_equal, on_no_match);
// Increment pointers into capture and match string.
__ addq(rbx, Immediate(char_size()));
__ addq(rdx, Immediate(char_size()));
// Check if we have reached end of match area.
__ cmpq(rdx, r9);
__ j(below, &loop);
// Success.
// Set current character position to position after match.
__ movq(rdi, rbx);
__ subq(rdi, rsi);
__ bind(&fallthrough);
}
void RegExpMacroAssemblerX64::CheckNotRegistersEqual(int reg1,
int reg2,
Label* on_not_equal) {
__ movq(rax, register_location(reg1));
__ cmpq(rax, register_location(reg2));
BranchOrBacktrack(not_equal, on_not_equal);
}
void RegExpMacroAssemblerX64::CheckNotCharacter(uint32_t c,
Label* on_not_equal) {
__ cmpl(current_character(), Immediate(c));
BranchOrBacktrack(not_equal, on_not_equal);
}
void RegExpMacroAssemblerX64::CheckCharacterAfterAnd(uint32_t c,
uint32_t mask,
Label* on_equal) {
__ movl(rax, current_character());
__ and_(rax, Immediate(mask));
__ cmpl(rax, Immediate(c));
BranchOrBacktrack(equal, on_equal);
}
void RegExpMacroAssemblerX64::CheckNotCharacterAfterAnd(uint32_t c,
uint32_t mask,
Label* on_not_equal) {
__ movl(rax, current_character());
__ and_(rax, Immediate(mask));
__ cmpl(rax, Immediate(c));
BranchOrBacktrack(not_equal, on_not_equal);
}
void RegExpMacroAssemblerX64::CheckNotCharacterAfterMinusAnd(
uc16 c,
uc16 minus,
uc16 mask,
Label* on_not_equal) {
ASSERT(minus < String::kMaxUtf16CodeUnit);
__ lea(rax, Operand(current_character(), -minus));
__ and_(rax, Immediate(mask));
__ cmpl(rax, Immediate(c));
BranchOrBacktrack(not_equal, on_not_equal);
}
bool RegExpMacroAssemblerX64::CheckSpecialCharacterClass(uc16 type,
Label* on_no_match) {
// Range checks (c in min..max) are generally implemented by an unsigned
// (c - min) <= (max - min) check, using the sequence:
// lea(rax, Operand(current_character(), -min)) or sub(rax, Immediate(min))
// cmp(rax, Immediate(max - min))
switch (type) {
case 's':
// Match space-characters
if (mode_ == ASCII) {
// ASCII space characters are '\t'..'\r' and ' '.
Label success;
__ cmpl(current_character(), Immediate(' '));
__ j(equal, &success);
// Check range 0x09..0x0d
__ lea(rax, Operand(current_character(), -'\t'));
__ cmpl(rax, Immediate('\r' - '\t'));
BranchOrBacktrack(above, on_no_match);
__ bind(&success);
return true;
}
return false;
case 'S':
// Match non-space characters.
if (mode_ == ASCII) {
// ASCII space characters are '\t'..'\r' and ' '.
__ cmpl(current_character(), Immediate(' '));
BranchOrBacktrack(equal, on_no_match);
__ lea(rax, Operand(current_character(), -'\t'));
__ cmpl(rax, Immediate('\r' - '\t'));
BranchOrBacktrack(below_equal, on_no_match);
return true;
}
return false;
case 'd':
// Match ASCII digits ('0'..'9')
__ lea(rax, Operand(current_character(), -'0'));
__ cmpl(rax, Immediate('9' - '0'));
BranchOrBacktrack(above, on_no_match);
return true;
case 'D':
// Match non ASCII-digits
__ lea(rax, Operand(current_character(), -'0'));
__ cmpl(rax, Immediate('9' - '0'));
BranchOrBacktrack(below_equal, on_no_match);
return true;
case '.': {
// Match non-newlines (not 0x0a('\n'), 0x0d('\r'), 0x2028 and 0x2029)
__ movl(rax, current_character());
__ xor_(rax, Immediate(0x01));
// See if current character is '\n'^1 or '\r'^1, i.e., 0x0b or 0x0c
__ subl(rax, Immediate(0x0b));
__ cmpl(rax, Immediate(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.
__ subl(rax, Immediate(0x2028 - 0x0b));
__ cmpl(rax, Immediate(0x2029 - 0x2028));
BranchOrBacktrack(below_equal, on_no_match);
}
return true;
}
case 'n': {
// Match newlines (0x0a('\n'), 0x0d('\r'), 0x2028 and 0x2029)
__ movl(rax, current_character());
__ xor_(rax, Immediate(0x01));
// See if current character is '\n'^1 or '\r'^1, i.e., 0x0b or 0x0c
__ subl(rax, Immediate(0x0b));
__ cmpl(rax, Immediate(0x0c - 0x0b));
if (mode_ == ASCII) {
BranchOrBacktrack(above, on_no_match);
} else {
Label done;
BranchOrBacktrack(below_equal, &done);
// Compare original value to 0x2028 and 0x2029, using the already
// computed (current_char ^ 0x01 - 0x0b). I.e., check for
// 0x201d (0x2028 - 0x0b) or 0x201e.
__ subl(rax, Immediate(0x2028 - 0x0b));
__ cmpl(rax, Immediate(0x2029 - 0x2028));
BranchOrBacktrack(above, on_no_match);
__ bind(&done);
}
return true;
}
case 'w': {
if (mode_ != ASCII) {
// Table is 128 entries, so all ASCII characters can be tested.
__ cmpl(current_character(), Immediate('z'));
BranchOrBacktrack(above, on_no_match);
}
__ movq(rbx, ExternalReference::re_word_character_map());
ASSERT_EQ(0, word_character_map[0]); // Character '\0' is not a word char.
__ testb(Operand(rbx, current_character(), times_1, 0),
current_character());
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.
__ cmpl(current_character(), Immediate('z'));
__ j(above, &done);
}
__ movq(rbx, ExternalReference::re_word_character_map());
ASSERT_EQ(0, word_character_map[0]); // Character '\0' is not a word char.
__ testb(Operand(rbx, current_character(), times_1, 0),
current_character());
BranchOrBacktrack(not_zero, on_no_match);
if (mode_ != ASCII) {
__ bind(&done);
}
return true;
}
case '*':
// Match any character.
return true;
// No custom implementation (yet): s(UC16), S(UC16).
default:
return false;
}
}
void RegExpMacroAssemblerX64::Fail() {
ASSERT(FAILURE == 0); // Return value for failure is zero.
__ Set(rax, 0);
__ jmp(&exit_label_);
}
Handle<HeapObject> RegExpMacroAssemblerX64::GetCode(Handle<String> source) {
// 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
// is generated.
FrameScope scope(&masm_, StackFrame::MANUAL);
// Actually emit code to start a new stack frame.
__ push(rbp);
__ movq(rbp, rsp);
// Save parameters and callee-save registers. Order here should correspond
// to order of kBackup_ebx etc.
#ifdef _WIN64
// MSVC passes arguments in rcx, rdx, r8, r9, with backing stack slots.
// Store register parameters in pre-allocated stack slots,
__ movq(Operand(rbp, kInputString), rcx);
__ movq(Operand(rbp, kStartIndex), rdx); // Passed as int32 in edx.
__ movq(Operand(rbp, kInputStart), r8);
__ movq(Operand(rbp, kInputEnd), r9);
// Callee-save on Win64.
__ push(rsi);
__ push(rdi);
__ push(rbx);
#else
// GCC passes arguments in rdi, rsi, rdx, rcx, r8, r9 (and then on stack).
// Push register parameters on stack for reference.
ASSERT_EQ(kInputString, -1 * kPointerSize);
ASSERT_EQ(kStartIndex, -2 * kPointerSize);
ASSERT_EQ(kInputStart, -3 * kPointerSize);
ASSERT_EQ(kInputEnd, -4 * kPointerSize);
ASSERT_EQ(kRegisterOutput, -5 * kPointerSize);
ASSERT_EQ(kStackHighEnd, -6 * kPointerSize);
__ push(rdi);
__ push(rsi);
__ push(rdx);
__ push(rcx);
__ push(r8);
__ push(r9);
__ push(rbx); // Callee-save
#endif
__ push(Immediate(0)); // Make room for "at start" 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(masm_.isolate());
__ movq(rcx, rsp);
__ movq(kScratchRegister, stack_limit);
__ subq(rcx, Operand(kScratchRegister, 0));
// 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.
__ cmpq(rcx, Immediate(num_registers_ * kPointerSize));
__ j(above_equal, &stack_ok);
// Exit with OutOfMemory exception. There is not enough space on the stack
// for our working registers.
__ Set(rax, EXCEPTION);
__ jmp(&exit_label_);
__ bind(&stack_limit_hit);
__ Move(code_object_pointer(), masm_.CodeObject());
CallCheckStackGuardState(); // Preserves no registers beside rbp and rsp.
__ testq(rax, rax);
// If returned value is non-zero, we exit with the returned value as result.
__ j(not_zero, &exit_label_);
__ bind(&stack_ok);
// Allocate space on stack for registers.
__ subq(rsp, Immediate(num_registers_ * kPointerSize));
// Load string length.
__ movq(rsi, Operand(rbp, kInputEnd));
// Load input position.
__ movq(rdi, Operand(rbp, kInputStart));
// Set up rdi to be negative offset from string end.
__ subq(rdi, rsi);
// Set rax to address of char before start of the string
// (effectively string position -1).
__ movq(rbx, Operand(rbp, kStartIndex));
__ neg(rbx);
if (mode_ == UC16) {
__ lea(rax, Operand(rdi, rbx, times_2, -char_size()));
} else {
__ lea(rax, Operand(rdi, rbx, times_1, -char_size()));
}
// Store this value in a local variable, for use when clearing
// position registers.
__ movq(Operand(rbp, kInputStartMinusOne), rax);
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).
__ Set(rcx, kRegisterZero);
Label init_loop;
__ bind(&init_loop);
__ movq(Operand(rbp, rcx, times_1, 0), rax);
__ subq(rcx, Immediate(kPointerSize));
__ cmpq(rcx,
Immediate(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) {
__ movq(register_location(i), rax); // One write every page.
}
// Initialize backtrack stack pointer.
__ movq(backtrack_stackpointer(), Operand(rbp, kStackHighEnd));
// Initialize code object pointer.
__ Move(code_object_pointer(), masm_.CodeObject());
// Load previous char as initial value of current-character.
Label at_start;
__ cmpb(Operand(rbp, kStartIndex), Immediate(0));
__ j(equal, &at_start);
LoadCurrentCharacterUnchecked(-1, 1); // Load previous char.
__ jmp(&start_label_);
__ bind(&at_start);
__ Set(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
__ movq(rdx, Operand(rbp, kStartIndex));
__ movq(rbx, Operand(rbp, kRegisterOutput));
__ movq(rcx, Operand(rbp, kInputEnd));
__ subq(rcx, Operand(rbp, kInputStart));
if (mode_ == UC16) {
__ lea(rcx, Operand(rcx, rdx, times_2, 0));
} else {
__ addq(rcx, rdx);
}
for (int i = 0; i < num_saved_registers_; i++) {
__ movq(rax, register_location(i));
__ addq(rax, rcx); // Convert to index from start, not end.
if (mode_ == UC16) {
__ sar(rax, Immediate(1)); // Convert byte index to character index.
}
__ movl(Operand(rbx, i * kIntSize), rax);
}
}
__ Set(rax, SUCCESS);
}
// Exit and return rax
__ bind(&exit_label_);
#ifdef _WIN64
// Restore callee save registers.
__ lea(rsp, Operand(rbp, kLastCalleeSaveRegister));
__ pop(rbx);
__ pop(rdi);
__ pop(rsi);
// Stack now at rbp.
#else
// Restore callee save register.
__ movq(rbx, Operand(rbp, kBackup_rbx));
// Skip rsp to rbp.
__ movq(rsp, rbp);
#endif
// Exit function frame, restore previous one.
__ pop(rbp);
__ 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(rdi);
CallCheckStackGuardState();
__ testq(rax, rax);
// If returning non-zero, we should end execution with the given
// result as return value.
__ j(not_zero, &exit_label_);
// Restore registers.
__ Move(code_object_pointer(), masm_.CodeObject());
__ pop(rdi);
__ pop(backtrack_stackpointer());
// String might have moved: Reload esi from frame.
__ movq(rsi, Operand(rbp, 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
#ifndef _WIN64
// Callee-save in Microsoft 64-bit ABI, but not in AMD64 ABI.
__ push(rsi);
__ push(rdi);
#endif
// Call GrowStack(backtrack_stackpointer())
static const int num_arguments = 3;
__ PrepareCallCFunction(num_arguments);
#ifdef _WIN64
// Microsoft passes parameters in rcx, rdx, r8.
// First argument, backtrack stackpointer, is already in rcx.
__ lea(rdx, Operand(rbp, kStackHighEnd)); // Second argument
__ LoadAddress(r8, ExternalReference::isolate_address());
#else
// AMD64 ABI passes parameters in rdi, rsi, rdx.
__ movq(rdi, backtrack_stackpointer()); // First argument.
__ lea(rsi, Operand(rbp, kStackHighEnd)); // Second argument.
__ LoadAddress(rdx, ExternalReference::isolate_address());
#endif
ExternalReference grow_stack =
ExternalReference::re_grow_stack(masm_.isolate());
__ CallCFunction(grow_stack, num_arguments);
// If return NULL, we have failed to grow the stack, and
// must exit with a stack-overflow exception.
__ testq(rax, rax);
__ j(equal, &exit_with_exception);
// Otherwise use return value as new stack pointer.
__ movq(backtrack_stackpointer(), rax);
// Restore saved registers and continue.
__ Move(code_object_pointer(), masm_.CodeObject());
#ifndef _WIN64
__ pop(rdi);
__ pop(rsi);
#endif
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.
__ Set(rax, EXCEPTION);
__ jmp(&exit_label_);
}
FixupCodeRelativePositions();
CodeDesc code_desc;
masm_.GetCode(&code_desc);
Isolate* isolate = ISOLATE;
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 RegExpMacroAssemblerX64::GoTo(Label* to) {
BranchOrBacktrack(no_condition, to);
}
void RegExpMacroAssemblerX64::IfRegisterGE(int reg,
int comparand,
Label* if_ge) {
__ cmpq(register_location(reg), Immediate(comparand));
BranchOrBacktrack(greater_equal, if_ge);
}
void RegExpMacroAssemblerX64::IfRegisterLT(int reg,
int comparand,
Label* if_lt) {
__ cmpq(register_location(reg), Immediate(comparand));
BranchOrBacktrack(less, if_lt);
}
void RegExpMacroAssemblerX64::IfRegisterEqPos(int reg,
Label* if_eq) {
__ cmpq(rdi, register_location(reg));
BranchOrBacktrack(equal, if_eq);
}
RegExpMacroAssembler::IrregexpImplementation
RegExpMacroAssemblerX64::Implementation() {
return kX64Implementation;
}
void RegExpMacroAssemblerX64::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)
if (check_bounds) {
CheckPosition(cp_offset + characters - 1, on_end_of_input);
}
LoadCurrentCharacterUnchecked(cp_offset, characters);
}
void RegExpMacroAssemblerX64::PopCurrentPosition() {
Pop(rdi);
}
void RegExpMacroAssemblerX64::PopRegister(int register_index) {
Pop(rax);
__ movq(register_location(register_index), rax);
}
void RegExpMacroAssemblerX64::PushBacktrack(Label* label) {
Push(label);
CheckStackLimit();
}
void RegExpMacroAssemblerX64::PushCurrentPosition() {
Push(rdi);
}
void RegExpMacroAssemblerX64::PushRegister(int register_index,
StackCheckFlag check_stack_limit) {
__ movq(rax, register_location(register_index));
Push(rax);
if (check_stack_limit) CheckStackLimit();
}
void RegExpMacroAssemblerX64::ReadCurrentPositionFromRegister(int reg) {
__ movq(rdi, register_location(reg));
}
void RegExpMacroAssemblerX64::ReadStackPointerFromRegister(int reg) {
__ movq(backtrack_stackpointer(), register_location(reg));
__ addq(backtrack_stackpointer(), Operand(rbp, kStackHighEnd));
}
void RegExpMacroAssemblerX64::SetCurrentPositionFromEnd(int by) {
Label after_position;
__ cmpq(rdi, Immediate(-by * char_size()));
__ j(greater_equal, &after_position, Label::kNear);
__ movq(rdi, Immediate(-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 RegExpMacroAssemblerX64::SetRegister(int register_index, int to) {
ASSERT(register_index >= num_saved_registers_); // Reserved for positions!
__ movq(register_location(register_index), Immediate(to));
}
void RegExpMacroAssemblerX64::Succeed() {
__ jmp(&success_label_);
}
void RegExpMacroAssemblerX64::WriteCurrentPositionToRegister(int reg,
int cp_offset) {
if (cp_offset == 0) {
__ movq(register_location(reg), rdi);
} else {
__ lea(rax, Operand(rdi, cp_offset * char_size()));
__ movq(register_location(reg), rax);
}
}
void RegExpMacroAssemblerX64::ClearRegisters(int reg_from, int reg_to) {
ASSERT(reg_from <= reg_to);
__ movq(rax, Operand(rbp, kInputStartMinusOne));
for (int reg = reg_from; reg <= reg_to; reg++) {
__ movq(register_location(reg), rax);
}
}
void RegExpMacroAssemblerX64::WriteStackPointerToRegister(int reg) {
__ movq(rax, backtrack_stackpointer());
__ subq(rax, Operand(rbp, kStackHighEnd));
__ movq(register_location(reg), rax);
}
// Private methods:
void RegExpMacroAssemblerX64::CallCheckStackGuardState() {
// This function call preserves no register values. Caller should
// store anything volatile in a C call or overwritten by this function.
static const int num_arguments = 3;
__ PrepareCallCFunction(num_arguments);
#ifdef _WIN64
// Second argument: Code* of self. (Do this before overwriting r8).
__ movq(rdx, code_object_pointer());
// Third argument: RegExp code frame pointer.
__ movq(r8, rbp);
// First argument: Next address on the stack (will be address of
// return address).
__ lea(rcx, Operand(rsp, -kPointerSize));
#else
// Third argument: RegExp code frame pointer.
__ movq(rdx, rbp);
// Second argument: Code* of self.
__ movq(rsi, code_object_pointer());
// First argument: Next address on the stack (will be address of
// return address).
__ lea(rdi, Operand(rsp, -kPointerSize));
#endif
ExternalReference stack_check =
ExternalReference::re_check_stack_guard_state(masm_.isolate());
__ CallCFunction(stack_check, 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 RegExpMacroAssemblerX64::CheckStackGuardState(Address* return_address,
Code* re_code,
Address re_frame) {
Isolate* isolate = frame_entry<Isolate*>(re_frame, kIsolate);
ASSERT(isolate == Isolate::Current());
if (isolate->stack_guard()->IsStackOverflow()) {
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->IsAsciiRepresentationUnderneath();
ASSERT(re_code->instruction_start() <= *return_address);
ASSERT(*return_address <=
re_code->instruction_start() + re_code->instruction_size());
MaybeObject* result = Execution::HandleStackGuardInterrupt(isolate);
if (*code_handle != re_code) { // Return address no longer valid
intptr_t 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->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_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 RegExpMacroAssemblerX64::register_location(int register_index) {
ASSERT(register_index < (1<<30));
if (num_registers_ <= register_index) {
num_registers_ = register_index + 1;
}
return Operand(rbp, kRegisterZero - register_index * kPointerSize);
}
void RegExpMacroAssemblerX64::CheckPosition(int cp_offset,
Label* on_outside_input) {
__ cmpl(rdi, Immediate(-cp_offset * char_size()));
BranchOrBacktrack(greater_equal, on_outside_input);
}
void RegExpMacroAssemblerX64::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 RegExpMacroAssemblerX64::SafeCall(Label* to) {
__ call(to);
}
void RegExpMacroAssemblerX64::SafeCallTarget(Label* label) {
__ bind(label);
__ subq(Operand(rsp, 0), code_object_pointer());
}
void RegExpMacroAssemblerX64::SafeReturn() {
__ addq(Operand(rsp, 0), code_object_pointer());
__ ret(0);
}
void RegExpMacroAssemblerX64::Push(Register source) {
ASSERT(!source.is(backtrack_stackpointer()));
// Notice: This updates flags, unlike normal Push.
__ subq(backtrack_stackpointer(), Immediate(kIntSize));
__ movl(Operand(backtrack_stackpointer(), 0), source);
}
void RegExpMacroAssemblerX64::Push(Immediate value) {
// Notice: This updates flags, unlike normal Push.
__ subq(backtrack_stackpointer(), Immediate(kIntSize));
__ movl(Operand(backtrack_stackpointer(), 0), value);
}
void RegExpMacroAssemblerX64::FixupCodeRelativePositions() {
for (int i = 0, n = code_relative_fixup_positions_.length(); i < n; i++) {
int position = code_relative_fixup_positions_[i];
// The position succeeds a relative label offset from position.
// Patch the relative offset to be relative to the Code object pointer
// instead.
int patch_position = position - kIntSize;
int offset = masm_.long_at(patch_position);
masm_.long_at_put(patch_position,
offset
+ position
+ Code::kHeaderSize
- kHeapObjectTag);
}
code_relative_fixup_positions_.Clear();
}
void RegExpMacroAssemblerX64::Push(Label* backtrack_target) {
__ subq(backtrack_stackpointer(), Immediate(kIntSize));
__ movl(Operand(backtrack_stackpointer(), 0), backtrack_target);
MarkPositionForCodeRelativeFixup();
}
void RegExpMacroAssemblerX64::Pop(Register target) {
ASSERT(!target.is(backtrack_stackpointer()));
__ movsxlq(target, Operand(backtrack_stackpointer(), 0));
// Notice: This updates flags, unlike normal Pop.
__ addq(backtrack_stackpointer(), Immediate(kIntSize));
}
void RegExpMacroAssemblerX64::Drop() {
__ addq(backtrack_stackpointer(), Immediate(kIntSize));
}
void RegExpMacroAssemblerX64::CheckPreemption() {
// Check for preemption.
Label no_preempt;
ExternalReference stack_limit =
ExternalReference::address_of_stack_limit(masm_.isolate());
__ load_rax(stack_limit);
__ cmpq(rsp, rax);
__ j(above, &no_preempt);
SafeCall(&check_preempt_label_);
__ bind(&no_preempt);
}
void RegExpMacroAssemblerX64::CheckStackLimit() {
Label no_stack_overflow;
ExternalReference stack_limit =
ExternalReference::address_of_regexp_stack_limit(masm_.isolate());
__ load_rax(stack_limit);
__ cmpq(backtrack_stackpointer(), rax);
__ j(above, &no_stack_overflow);
SafeCall(&stack_overflow_label_);
__ bind(&no_stack_overflow);
}
void RegExpMacroAssemblerX64::LoadCurrentCharacterUnchecked(int cp_offset,
int characters) {
if (mode_ == ASCII) {
if (characters == 4) {
__ movl(current_character(), Operand(rsi, rdi, times_1, cp_offset));
} else if (characters == 2) {
__ movzxwl(current_character(), Operand(rsi, rdi, times_1, cp_offset));
} else {
ASSERT(characters == 1);
__ movzxbl(current_character(), Operand(rsi, rdi, times_1, cp_offset));
}
} else {
ASSERT(mode_ == UC16);
if (characters == 2) {
__ movl(current_character(),
Operand(rsi, rdi, times_1, cp_offset * sizeof(uc16)));
} else {
ASSERT(characters == 1);
__ movzxwl(current_character(),
Operand(rsi, rdi, times_1, cp_offset * sizeof(uc16)));
}
}
}
#undef __
#endif // V8_INTERPRETED_REGEXP
}} // namespace v8::internal
#endif // V8_TARGET_ARCH_X64