// Copyright 2012 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_MIPS)
#include "unicode.h"
#include "log.h"
#include "code-stubs.h"
#include "regexp-stack.h"
#include "macro-assembler.h"
#include "regexp-macro-assembler.h"
#include "mips/regexp-macro-assembler-mips.h"
namespace v8 {
namespace internal {
#ifndef V8_INTERPRETED_REGEXP
/*
* This assembler uses the following register assignment convention
* - t1 : Pointer to current code object (Code*) including heap object tag.
* - t2 : Current position in input, as negative offset from end of string.
* Please notice that this is the byte offset, not the character offset!
* - t3 : Currently loaded character. Must be loaded using
* LoadCurrentCharacter before using any of the dispatch methods.
* - t4 : points to tip of backtrack stack
* - t5 : Unused.
* - t6 : End of input (points to byte after last character in input).
* - fp : Frame pointer. Used to access arguments, local variables and
* RegExp registers.
* - sp : points to tip of C stack.
*
* The remaining registers are free for computations.
* Each call to a public method should retain this convention.
*
* The stack will have the following structure:
*
* - fp[56] direct_call (if 1, direct call from JavaScript code,
* if 0, call through the runtime system).
* - fp[52] stack_area_base (High end of the memory area to use as
* backtracking stack).
* - fp[48] int* capture_array (int[num_saved_registers_], for output).
* - fp[44] secondary link/return address used by native call.
* --- sp when called ---
* - fp[40] return address (lr).
* - fp[36] old frame pointer (r11).
* - fp[0..32] backup of registers s0..s7.
* --- frame pointer ----
* - fp[-4] end of input (Address of end of string).
* - fp[-8] start of input (Address of first character in string).
* - fp[-12] start index (character index of start).
* - fp[-16] void* input_string (location of a handle containing the string).
* - fp[-20] Offset of location before start of input (effectively character
* position -1). Used to initialize capture registers to a
* non-position.
* - fp[-24] At start (if 1, we are starting at the start of the
* string, otherwise 0)
* - fp[-28] register 0 (Only positions must be stored in the first
* - register 1 num_saved_registers_ registers)
* - ...
* - register num_registers-1
* --- sp ---
*
* The first num_saved_registers_ registers are initialized to point to
* "character -1" in the string (i.e., char_size() bytes before the first
* character of the string). The remaining registers start out as garbage.
*
* The data up to the return address must be placed there by the calling
* code and the remaining arguments are passed in registers, e.g. by calling the
* code entry as cast to a function with the signature:
* int (*match)(String* input_string,
* int start_index,
* Address start,
* Address end,
* Address secondary_return_address, // Only used by native call.
* int* capture_output_array,
* byte* stack_area_base,
* bool direct_call = false)
* The call is performed by NativeRegExpMacroAssembler::Execute()
* (in regexp-macro-assembler.cc) via the CALL_GENERATED_REGEXP_CODE macro
* in mips/simulator-mips.h.
* When calling as a non-direct call (i.e., from C++ code), the return address
* area is overwritten with the ra register by the RegExp code. When doing a
* direct call from generated code, the return address is placed there by
* the calling code, as in a normal exit frame.
*/
#define __ ACCESS_MASM(masm_)
RegExpMacroAssemblerMIPS::RegExpMacroAssemblerMIPS(
Mode mode,
int registers_to_save)
: masm_(new MacroAssembler(Isolate::Current(), 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_(),
internal_failure_label_() {
ASSERT_EQ(0, registers_to_save % 2);
__ jmp(&entry_label_); // We'll write the entry code later.
// If the code gets too big or corrupted, an internal exception will be
// raised, and we will exit right away.
__ bind(&internal_failure_label_);
__ li(v0, Operand(FAILURE));
__ Ret();
__ bind(&start_label_); // And then continue from here.
}
RegExpMacroAssemblerMIPS::~RegExpMacroAssemblerMIPS() {
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();
internal_failure_label_.Unuse();
}
int RegExpMacroAssemblerMIPS::stack_limit_slack() {
return RegExpStack::kStackLimitSlack;
}
void RegExpMacroAssemblerMIPS::AdvanceCurrentPosition(int by) {
if (by != 0) {
__ Addu(current_input_offset(),
current_input_offset(), Operand(by * char_size()));
}
}
void RegExpMacroAssemblerMIPS::AdvanceRegister(int reg, int by) {
ASSERT(reg >= 0);
ASSERT(reg < num_registers_);
if (by != 0) {
__ lw(a0, register_location(reg));
__ Addu(a0, a0, Operand(by));
__ sw(a0, register_location(reg));
}
}
void RegExpMacroAssemblerMIPS::Backtrack() {
CheckPreemption();
// Pop Code* offset from backtrack stack, add Code* and jump to location.
Pop(a0);
__ Addu(a0, a0, code_pointer());
__ Jump(a0);
}
void RegExpMacroAssemblerMIPS::Bind(Label* label) {
__ bind(label);
}
void RegExpMacroAssemblerMIPS::CheckCharacter(uint32_t c, Label* on_equal) {
BranchOrBacktrack(on_equal, eq, current_character(), Operand(c));
}
void RegExpMacroAssemblerMIPS::CheckCharacterGT(uc16 limit, Label* on_greater) {
BranchOrBacktrack(on_greater, gt, current_character(), Operand(limit));
}
void RegExpMacroAssemblerMIPS::CheckAtStart(Label* on_at_start) {
Label not_at_start;
// Did we start the match at the start of the string at all?
__ lw(a0, MemOperand(frame_pointer(), kAtStart));
BranchOrBacktrack(¬_at_start, eq, a0, Operand(zero_reg));
// If we did, are we still at the start of the input?
__ lw(a1, MemOperand(frame_pointer(), kInputStart));
__ Addu(a0, end_of_input_address(), Operand(current_input_offset()));
BranchOrBacktrack(on_at_start, eq, a0, Operand(a1));
__ bind(¬_at_start);
}
void RegExpMacroAssemblerMIPS::CheckNotAtStart(Label* on_not_at_start) {
// Did we start the match at the start of the string at all?
__ lw(a0, MemOperand(frame_pointer(), kAtStart));
BranchOrBacktrack(on_not_at_start, eq, a0, Operand(zero_reg));
// If we did, are we still at the start of the input?
__ lw(a1, MemOperand(frame_pointer(), kInputStart));
__ Addu(a0, end_of_input_address(), Operand(current_input_offset()));
BranchOrBacktrack(on_not_at_start, ne, a0, Operand(a1));
}
void RegExpMacroAssemblerMIPS::CheckCharacterLT(uc16 limit, Label* on_less) {
BranchOrBacktrack(on_less, lt, current_character(), Operand(limit));
}
void RegExpMacroAssemblerMIPS::CheckCharacters(Vector<const uc16> str,
int cp_offset,
Label* on_failure,
bool check_end_of_string) {
if (on_failure == NULL) {
// Instead of inlining a backtrack for each test, (re)use the global
// backtrack target.
on_failure = &backtrack_label_;
}
if (check_end_of_string) {
// Is last character of required match inside string.
CheckPosition(cp_offset + str.length() - 1, on_failure);
}
__ Addu(a0, end_of_input_address(), Operand(current_input_offset()));
if (cp_offset != 0) {
int byte_offset = cp_offset * char_size();
__ Addu(a0, a0, Operand(byte_offset));
}
// a0 : Address of characters to match against str.
int stored_high_byte = 0;
for (int i = 0; i < str.length(); i++) {
if (mode_ == ASCII) {
__ lbu(a1, MemOperand(a0, 0));
__ addiu(a0, a0, char_size());
ASSERT(str[i] <= String::kMaxAsciiCharCode);
BranchOrBacktrack(on_failure, ne, a1, Operand(str[i]));
} else {
__ lhu(a1, MemOperand(a0, 0));
__ addiu(a0, a0, char_size());
uc16 match_char = str[i];
int match_high_byte = (match_char >> 8);
if (match_high_byte == 0) {
BranchOrBacktrack(on_failure, ne, a1, Operand(str[i]));
} else {
if (match_high_byte != stored_high_byte) {
__ li(a2, Operand(match_high_byte));
stored_high_byte = match_high_byte;
}
__ Addu(a3, a2, Operand(match_char & 0xff));
BranchOrBacktrack(on_failure, ne, a1, Operand(a3));
}
}
}
}
void RegExpMacroAssemblerMIPS::CheckGreedyLoop(Label* on_equal) {
Label backtrack_non_equal;
__ lw(a0, MemOperand(backtrack_stackpointer(), 0));
__ Branch(&backtrack_non_equal, ne, current_input_offset(), Operand(a0));
__ Addu(backtrack_stackpointer(),
backtrack_stackpointer(),
Operand(kPointerSize));
__ bind(&backtrack_non_equal);
BranchOrBacktrack(on_equal, eq, current_input_offset(), Operand(a0));
}
void RegExpMacroAssemblerMIPS::CheckNotBackReferenceIgnoreCase(
int start_reg,
Label* on_no_match) {
Label fallthrough;
__ lw(a0, register_location(start_reg)); // Index of start of capture.
__ lw(a1, register_location(start_reg + 1)); // Index of end of capture.
__ Subu(a1, a1, a0); // Length of capture.
// If length is zero, either the capture is empty or it is not participating.
// In either case succeed immediately.
__ Branch(&fallthrough, eq, a1, Operand(zero_reg));
__ Addu(t5, a1, current_input_offset());
// Check that there are enough characters left in the input.
BranchOrBacktrack(on_no_match, gt, t5, Operand(zero_reg));
if (mode_ == ASCII) {
Label success;
Label fail;
Label loop_check;
// a0 - offset of start of capture.
// a1 - length of capture.
__ Addu(a0, a0, Operand(end_of_input_address()));
__ Addu(a2, end_of_input_address(), Operand(current_input_offset()));
__ Addu(a1, a0, Operand(a1));
// a0 - Address of start of capture.
// a1 - Address of end of capture.
// a2 - Address of current input position.
Label loop;
__ bind(&loop);
__ lbu(a3, MemOperand(a0, 0));
__ addiu(a0, a0, char_size());
__ lbu(t0, MemOperand(a2, 0));
__ addiu(a2, a2, char_size());
__ Branch(&loop_check, eq, t0, Operand(a3));
// Mismatch, try case-insensitive match (converting letters to lower-case).
__ Or(a3, a3, Operand(0x20)); // Convert capture character to lower-case.
__ Or(t0, t0, Operand(0x20)); // Also convert input character.
__ Branch(&fail, ne, t0, Operand(a3));
__ Subu(a3, a3, Operand('a'));
__ Branch(&fail, hi, a3, Operand('z' - 'a')); // Is a3 a lowercase letter?
__ bind(&loop_check);
__ Branch(&loop, lt, a0, Operand(a1));
__ jmp(&success);
__ bind(&fail);
GoTo(on_no_match);
__ bind(&success);
// Compute new value of character position after the matched part.
__ Subu(current_input_offset(), a2, end_of_input_address());
} else {
ASSERT(mode_ == UC16);
// Put regexp engine registers on stack.
RegList regexp_registers_to_retain = current_input_offset().bit() |
current_character().bit() | backtrack_stackpointer().bit();
__ MultiPush(regexp_registers_to_retain);
int argument_count = 4;
__ PrepareCallCFunction(argument_count, a2);
// a0 - offset of start of capture.
// a1 - length of capture.
// Put arguments into arguments registers.
// Parameters are
// a0: Address byte_offset1 - Address captured substring's start.
// a1: Address byte_offset2 - Address of current character position.
// a2: size_t byte_length - length of capture in bytes(!).
// a3: Isolate* isolate.
// Address of start of capture.
__ Addu(a0, a0, Operand(end_of_input_address()));
// Length of capture.
__ mov(a2, a1);
// Save length in callee-save register for use on return.
__ mov(s3, a1);
// Address of current input position.
__ Addu(a1, current_input_offset(), Operand(end_of_input_address()));
// Isolate.
__ li(a3, Operand(ExternalReference::isolate_address()));
{
AllowExternalCallThatCantCauseGC scope(masm_);
ExternalReference function =
ExternalReference::re_case_insensitive_compare_uc16(masm_->isolate());
__ CallCFunction(function, argument_count);
}
// Restore regexp engine registers.
__ MultiPop(regexp_registers_to_retain);
__ li(code_pointer(), Operand(masm_->CodeObject()), CONSTANT_SIZE);
__ lw(end_of_input_address(), MemOperand(frame_pointer(), kInputEnd));
// Check if function returned non-zero for success or zero for failure.
BranchOrBacktrack(on_no_match, eq, v0, Operand(zero_reg));
// On success, increment position by length of capture.
__ Addu(current_input_offset(), current_input_offset(), Operand(s3));
}
__ bind(&fallthrough);
}
void RegExpMacroAssemblerMIPS::CheckNotBackReference(
int start_reg,
Label* on_no_match) {
Label fallthrough;
Label success;
// Find length of back-referenced capture.
__ lw(a0, register_location(start_reg));
__ lw(a1, register_location(start_reg + 1));
__ Subu(a1, a1, a0); // Length to check.
// Succeed on empty capture (including no capture).
__ Branch(&fallthrough, eq, a1, Operand(zero_reg));
__ Addu(t5, a1, current_input_offset());
// Check that there are enough characters left in the input.
BranchOrBacktrack(on_no_match, gt, t5, Operand(zero_reg));
// Compute pointers to match string and capture string.
__ Addu(a0, a0, Operand(end_of_input_address()));
__ Addu(a2, end_of_input_address(), Operand(current_input_offset()));
__ Addu(a1, a1, Operand(a0));
Label loop;
__ bind(&loop);
if (mode_ == ASCII) {
__ lbu(a3, MemOperand(a0, 0));
__ addiu(a0, a0, char_size());
__ lbu(t0, MemOperand(a2, 0));
__ addiu(a2, a2, char_size());
} else {
ASSERT(mode_ == UC16);
__ lhu(a3, MemOperand(a0, 0));
__ addiu(a0, a0, char_size());
__ lhu(t0, MemOperand(a2, 0));
__ addiu(a2, a2, char_size());
}
BranchOrBacktrack(on_no_match, ne, a3, Operand(t0));
__ Branch(&loop, lt, a0, Operand(a1));
// Move current character position to position after match.
__ Subu(current_input_offset(), a2, end_of_input_address());
__ bind(&fallthrough);
}
void RegExpMacroAssemblerMIPS::CheckNotRegistersEqual(int reg1,
int reg2,
Label* on_not_equal) {
UNIMPLEMENTED_MIPS();
}
void RegExpMacroAssemblerMIPS::CheckNotCharacter(uint32_t c,
Label* on_not_equal) {
BranchOrBacktrack(on_not_equal, ne, current_character(), Operand(c));
}
void RegExpMacroAssemblerMIPS::CheckCharacterAfterAnd(uint32_t c,
uint32_t mask,
Label* on_equal) {
__ And(a0, current_character(), Operand(mask));
BranchOrBacktrack(on_equal, eq, a0, Operand(c));
}
void RegExpMacroAssemblerMIPS::CheckNotCharacterAfterAnd(uint32_t c,
uint32_t mask,
Label* on_not_equal) {
__ And(a0, current_character(), Operand(mask));
BranchOrBacktrack(on_not_equal, ne, a0, Operand(c));
}
void RegExpMacroAssemblerMIPS::CheckNotCharacterAfterMinusAnd(
uc16 c,
uc16 minus,
uc16 mask,
Label* on_not_equal) {
UNIMPLEMENTED_MIPS();
}
bool RegExpMacroAssemblerMIPS::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) {
// ASCII space characters are '\t'..'\r' and ' '.
Label success;
__ Branch(&success, eq, current_character(), Operand(' '));
// Check range 0x09..0x0d.
__ Subu(a0, current_character(), Operand('\t'));
BranchOrBacktrack(on_no_match, hi, a0, Operand('\r' - '\t'));
__ bind(&success);
return true;
}
return false;
case 'S':
// Match non-space characters.
if (mode_ == ASCII) {
// ASCII space characters are '\t'..'\r' and ' '.
BranchOrBacktrack(on_no_match, eq, current_character(), Operand(' '));
__ Subu(a0, current_character(), Operand('\t'));
BranchOrBacktrack(on_no_match, ls, a0, Operand('\r' - '\t'));
return true;
}
return false;
case 'd':
// Match ASCII digits ('0'..'9').
__ Subu(a0, current_character(), Operand('0'));
BranchOrBacktrack(on_no_match, hi, a0, Operand('9' - '0'));
return true;
case 'D':
// Match non ASCII-digits.
__ Subu(a0, current_character(), Operand('0'));
BranchOrBacktrack(on_no_match, ls, a0, Operand('9' - '0'));
return true;
case '.': {
// Match non-newlines (not 0x0a('\n'), 0x0d('\r'), 0x2028 and 0x2029).
__ Xor(a0, current_character(), Operand(0x01));
// See if current character is '\n'^1 or '\r'^1, i.e., 0x0b or 0x0c.
__ Subu(a0, a0, Operand(0x0b));
BranchOrBacktrack(on_no_match, ls, a0, Operand(0x0c - 0x0b));
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.
__ Subu(a0, a0, Operand(0x2028 - 0x0b));
BranchOrBacktrack(on_no_match, ls, a0, Operand(1));
}
return true;
}
case 'n': {
// Match newlines (0x0a('\n'), 0x0d('\r'), 0x2028 and 0x2029).
__ Xor(a0, current_character(), Operand(0x01));
// See if current character is '\n'^1 or '\r'^1, i.e., 0x0b or 0x0c.
__ Subu(a0, a0, Operand(0x0b));
if (mode_ == ASCII) {
BranchOrBacktrack(on_no_match, hi, a0, Operand(0x0c - 0x0b));
} else {
Label done;
BranchOrBacktrack(&done, ls, a0, Operand(0x0c - 0x0b));
// Compare original value to 0x2028 and 0x2029, using the already
// computed (current_char ^ 0x01 - 0x0b). I.e., check for
// 0x201d (0x2028 - 0x0b) or 0x201e.
__ Subu(a0, a0, Operand(0x2028 - 0x0b));
BranchOrBacktrack(on_no_match, hi, a0, Operand(1));
__ bind(&done);
}
return true;
}
case 'w': {
if (mode_ != ASCII) {
// Table is 128 entries, so all ASCII characters can be tested.
BranchOrBacktrack(on_no_match, hi, current_character(), Operand('z'));
}
ExternalReference map = ExternalReference::re_word_character_map();
__ li(a0, Operand(map));
__ Addu(a0, a0, current_character());
__ lbu(a0, MemOperand(a0, 0));
BranchOrBacktrack(on_no_match, eq, a0, Operand(zero_reg));
return true;
}
case 'W': {
Label done;
if (mode_ != ASCII) {
// Table is 128 entries, so all ASCII characters can be tested.
__ Branch(&done, hi, current_character(), Operand('z'));
}
ExternalReference map = ExternalReference::re_word_character_map();
__ li(a0, Operand(map));
__ Addu(a0, a0, current_character());
__ lbu(a0, MemOperand(a0, 0));
BranchOrBacktrack(on_no_match, ne, a0, Operand(zero_reg));
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 RegExpMacroAssemblerMIPS::Fail() {
__ li(v0, Operand(FAILURE));
__ jmp(&exit_label_);
}
Handle<HeapObject> RegExpMacroAssemblerMIPS::GetCode(Handle<String> source) {
if (masm_->has_exception()) {
// If the code gets corrupted due to long regular expressions and lack of
// space on trampolines, an internal exception flag is set. If this case
// is detected, we will jump into exit sequence right away.
__ bind_to(&entry_label_, internal_failure_label_.pos());
} else {
// 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 arguments
// Save callee-save registers.
// Start new stack frame.
// Store link register in existing stack-cell.
// Order here should correspond to order of offset constants in header file.
RegList registers_to_retain = s0.bit() | s1.bit() | s2.bit() |
s3.bit() | s4.bit() | s5.bit() | s6.bit() | s7.bit() | fp.bit();
RegList argument_registers = a0.bit() | a1.bit() | a2.bit() | a3.bit();
__ MultiPush(argument_registers | registers_to_retain | ra.bit());
// Set frame pointer in space for it if this is not a direct call
// from generated code.
__ Addu(frame_pointer(), sp, Operand(4 * kPointerSize));
__ push(a0); // Make room for "position - 1" constant (value irrelevant).
__ push(a0); // Make room for "at start" constant (value irrelevant).
// 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());
__ li(a0, Operand(stack_limit));
__ lw(a0, MemOperand(a0));
__ Subu(a0, sp, a0);
// Handle it if the stack pointer is already below the stack limit.
__ Branch(&stack_limit_hit, le, a0, Operand(zero_reg));
// Check if there is room for the variable number of registers above
// the stack limit.
__ Branch(&stack_ok, hs, a0, Operand(num_registers_ * kPointerSize));
// Exit with OutOfMemory exception. There is not enough space on the stack
// for our working registers.
__ li(v0, Operand(EXCEPTION));
__ jmp(&exit_label_);
__ bind(&stack_limit_hit);
CallCheckStackGuardState(a0);
// If returned value is non-zero, we exit with the returned value as result.
__ Branch(&exit_label_, ne, v0, Operand(zero_reg));
__ bind(&stack_ok);
// Allocate space on stack for registers.
__ Subu(sp, sp, Operand(num_registers_ * kPointerSize));
// Load string end.
__ lw(end_of_input_address(), MemOperand(frame_pointer(), kInputEnd));
// Load input start.
__ lw(a0, MemOperand(frame_pointer(), kInputStart));
// Find negative length (offset of start relative to end).
__ Subu(current_input_offset(), a0, end_of_input_address());
// Set a0 to address of char before start of the input string
// (effectively string position -1).
__ lw(a1, MemOperand(frame_pointer(), kStartIndex));
__ Subu(a0, current_input_offset(), Operand(char_size()));
__ sll(t5, a1, (mode_ == UC16) ? 1 : 0);
__ Subu(a0, a0, t5);
// Store this value in a local variable, for use when clearing
// position registers.
__ sw(a0, MemOperand(frame_pointer(), kInputStartMinusOne));
// Determine whether the start index is zero, that is at the start of the
// string, and store that value in a local variable.
__ mov(t5, a1);
__ li(a1, Operand(1));
__ Movn(a1, zero_reg, t5);
__ sw(a1, MemOperand(frame_pointer(), kAtStart));
if (num_saved_registers_ > 0) { // Always is, if generated from a regexp.
// Fill saved registers with initial value = start offset - 1.
// Address of register 0.
__ Addu(a1, frame_pointer(), Operand(kRegisterZero));
__ li(a2, Operand(num_saved_registers_));
Label init_loop;
__ bind(&init_loop);
__ sw(a0, MemOperand(a1));
__ Addu(a1, a1, Operand(-kPointerSize));
__ Subu(a2, a2, Operand(1));
__ Branch(&init_loop, ne, a2, Operand(zero_reg));
}
// Initialize backtrack stack pointer.
__ lw(backtrack_stackpointer(), MemOperand(frame_pointer(), kStackHighEnd));
// Initialize code pointer register
__ li(code_pointer(), Operand(masm_->CodeObject()), CONSTANT_SIZE);
// Load previous char as initial value of current character register.
Label at_start;
__ lw(a0, MemOperand(frame_pointer(), kAtStart));
__ Branch(&at_start, ne, a0, Operand(zero_reg));
LoadCurrentCharacterUnchecked(-1, 1); // Load previous char.
__ jmp(&start_label_);
__ bind(&at_start);
__ li(current_character(), Operand('\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.
__ lw(a1, MemOperand(frame_pointer(), kInputStart));
__ lw(a0, MemOperand(frame_pointer(), kRegisterOutput));
__ lw(a2, MemOperand(frame_pointer(), kStartIndex));
__ Subu(a1, end_of_input_address(), a1);
// a1 is length of input in bytes.
if (mode_ == UC16) {
__ srl(a1, a1, 1);
}
// a1 is length of input in characters.
__ Addu(a1, a1, Operand(a2));
// a1 is length of string in characters.
ASSERT_EQ(0, num_saved_registers_ % 2);
// Always an even number of capture registers. This allows us to
// unroll the loop once to add an operation between a load of a register
// and the following use of that register.
for (int i = 0; i < num_saved_registers_; i += 2) {
__ lw(a2, register_location(i));
__ lw(a3, register_location(i + 1));
if (mode_ == UC16) {
__ sra(a2, a2, 1);
__ Addu(a2, a2, a1);
__ sra(a3, a3, 1);
__ Addu(a3, a3, a1);
} else {
__ Addu(a2, a1, Operand(a2));
__ Addu(a3, a1, Operand(a3));
}
__ sw(a2, MemOperand(a0));
__ Addu(a0, a0, kPointerSize);
__ sw(a3, MemOperand(a0));
__ Addu(a0, a0, kPointerSize);
}
}
__ li(v0, Operand(SUCCESS));
}
// Exit and return v0.
__ bind(&exit_label_);
// Skip sp past regexp registers and local variables..
__ mov(sp, frame_pointer());
// Restore registers s0..s7 and return (restoring ra to pc).
__ MultiPop(registers_to_retain | ra.bit());
__ Ret();
// 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_);
// Put regexp engine registers on stack.
RegList regexp_registers_to_retain = current_input_offset().bit() |
current_character().bit() | backtrack_stackpointer().bit();
__ MultiPush(regexp_registers_to_retain);
CallCheckStackGuardState(a0);
__ MultiPop(regexp_registers_to_retain);
// If returning non-zero, we should end execution with the given
// result as return value.
__ Branch(&exit_label_, ne, v0, Operand(zero_reg));
// String might have moved: Reload end of string from frame.
__ lw(end_of_input_address(), MemOperand(frame_pointer(), kInputEnd));
__ li(code_pointer(), Operand(masm_->CodeObject()), CONSTANT_SIZE);
SafeReturn();
}
// Backtrack stack overflow code.
if (stack_overflow_label_.is_linked()) {
SafeCallTarget(&stack_overflow_label_);
// Reached if the backtrack-stack limit has been hit.
// Put regexp engine registers on stack first.
RegList regexp_registers = current_input_offset().bit() |
current_character().bit();
__ MultiPush(regexp_registers);
Label grow_failed;
// Call GrowStack(backtrack_stackpointer(), &stack_base)
static const int num_arguments = 3;
__ PrepareCallCFunction(num_arguments, a0);
__ mov(a0, backtrack_stackpointer());
__ Addu(a1, frame_pointer(), Operand(kStackHighEnd));
__ li(a2, Operand(ExternalReference::isolate_address()));
ExternalReference grow_stack =
ExternalReference::re_grow_stack(masm_->isolate());
__ CallCFunction(grow_stack, num_arguments);
// Restore regexp registers.
__ MultiPop(regexp_registers);
// If return NULL, we have failed to grow the stack, and
// must exit with a stack-overflow exception.
__ Branch(&exit_with_exception, eq, v0, Operand(zero_reg));
// Otherwise use return value as new stack pointer.
__ mov(backtrack_stackpointer(), v0);
// Restore saved registers and continue.
__ li(code_pointer(), Operand(masm_->CodeObject()), CONSTANT_SIZE);
__ lw(end_of_input_address(), MemOperand(frame_pointer(), kInputEnd));
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.
__ li(v0, Operand(EXCEPTION));
__ jmp(&exit_label_);
}
}
CodeDesc code_desc;
masm_->GetCode(&code_desc);
Handle<Code> code = FACTORY->NewCode(code_desc,
Code::ComputeFlags(Code::REGEXP),
masm_->CodeObject());
LOG(Isolate::Current(), RegExpCodeCreateEvent(*code, *source));
return Handle<HeapObject>::cast(code);
}
void RegExpMacroAssemblerMIPS::GoTo(Label* to) {
if (to == NULL) {
Backtrack();
return;
}
__ jmp(to);
return;
}
void RegExpMacroAssemblerMIPS::IfRegisterGE(int reg,
int comparand,
Label* if_ge) {
__ lw(a0, register_location(reg));
BranchOrBacktrack(if_ge, ge, a0, Operand(comparand));
}
void RegExpMacroAssemblerMIPS::IfRegisterLT(int reg,
int comparand,
Label* if_lt) {
__ lw(a0, register_location(reg));
BranchOrBacktrack(if_lt, lt, a0, Operand(comparand));
}
void RegExpMacroAssemblerMIPS::IfRegisterEqPos(int reg,
Label* if_eq) {
__ lw(a0, register_location(reg));
BranchOrBacktrack(if_eq, eq, a0, Operand(current_input_offset()));
}
RegExpMacroAssembler::IrregexpImplementation
RegExpMacroAssemblerMIPS::Implementation() {
return kMIPSImplementation;
}
void RegExpMacroAssemblerMIPS::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 RegExpMacroAssemblerMIPS::PopCurrentPosition() {
Pop(current_input_offset());
}
void RegExpMacroAssemblerMIPS::PopRegister(int register_index) {
Pop(a0);
__ sw(a0, register_location(register_index));
}
void RegExpMacroAssemblerMIPS::PushBacktrack(Label* label) {
if (label->is_bound()) {
int target = label->pos();
__ li(a0, Operand(target + Code::kHeaderSize - kHeapObjectTag));
} else {
Label after_constant;
__ Branch(&after_constant);
int offset = masm_->pc_offset();
int cp_offset = offset + Code::kHeaderSize - kHeapObjectTag;
__ emit(0);
masm_->label_at_put(label, offset);
__ bind(&after_constant);
if (is_int16(cp_offset)) {
__ lw(a0, MemOperand(code_pointer(), cp_offset));
} else {
__ Addu(a0, code_pointer(), cp_offset);
__ lw(a0, MemOperand(a0, 0));
}
}
Push(a0);
CheckStackLimit();
}
void RegExpMacroAssemblerMIPS::PushCurrentPosition() {
Push(current_input_offset());
}
void RegExpMacroAssemblerMIPS::PushRegister(int register_index,
StackCheckFlag check_stack_limit) {
__ lw(a0, register_location(register_index));
Push(a0);
if (check_stack_limit) CheckStackLimit();
}
void RegExpMacroAssemblerMIPS::ReadCurrentPositionFromRegister(int reg) {
__ lw(current_input_offset(), register_location(reg));
}
void RegExpMacroAssemblerMIPS::ReadStackPointerFromRegister(int reg) {
__ lw(backtrack_stackpointer(), register_location(reg));
__ lw(a0, MemOperand(frame_pointer(), kStackHighEnd));
__ Addu(backtrack_stackpointer(), backtrack_stackpointer(), Operand(a0));
}
void RegExpMacroAssemblerMIPS::SetCurrentPositionFromEnd(int by) {
Label after_position;
__ Branch(&after_position,
ge,
current_input_offset(),
Operand(-by * char_size()));
__ li(current_input_offset(), -by * char_size());
// On RegExp code entry (where this operation is used), the character before
// the current position is expected to be already loaded.
// We have advanced the position, so it's safe to read backwards.
LoadCurrentCharacterUnchecked(-1, 1);
__ bind(&after_position);
}
void RegExpMacroAssemblerMIPS::SetRegister(int register_index, int to) {
ASSERT(register_index >= num_saved_registers_); // Reserved for positions!
__ li(a0, Operand(to));
__ sw(a0, register_location(register_index));
}
void RegExpMacroAssemblerMIPS::Succeed() {
__ jmp(&success_label_);
}
void RegExpMacroAssemblerMIPS::WriteCurrentPositionToRegister(int reg,
int cp_offset) {
if (cp_offset == 0) {
__ sw(current_input_offset(), register_location(reg));
} else {
__ Addu(a0, current_input_offset(), Operand(cp_offset * char_size()));
__ sw(a0, register_location(reg));
}
}
void RegExpMacroAssemblerMIPS::ClearRegisters(int reg_from, int reg_to) {
ASSERT(reg_from <= reg_to);
__ lw(a0, MemOperand(frame_pointer(), kInputStartMinusOne));
for (int reg = reg_from; reg <= reg_to; reg++) {
__ sw(a0, register_location(reg));
}
}
void RegExpMacroAssemblerMIPS::WriteStackPointerToRegister(int reg) {
__ lw(a1, MemOperand(frame_pointer(), kStackHighEnd));
__ Subu(a0, backtrack_stackpointer(), a1);
__ sw(a0, register_location(reg));
}
// Private methods:
void RegExpMacroAssemblerMIPS::CallCheckStackGuardState(Register scratch) {
static const int num_arguments = 3;
__ PrepareCallCFunction(num_arguments, scratch);
__ mov(a2, frame_pointer());
// Code* of self.
__ li(a1, Operand(masm_->CodeObject()), CONSTANT_SIZE);
// a0 becomes return address pointer.
ExternalReference stack_guard_check =
ExternalReference::re_check_stack_guard_state(masm_->isolate());
CallCFunctionUsingStub(stack_guard_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 RegExpMacroAssemblerMIPS::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.
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->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;
}
MemOperand RegExpMacroAssemblerMIPS::register_location(int register_index) {
ASSERT(register_index < (1<<30));
if (num_registers_ <= register_index) {
num_registers_ = register_index + 1;
}
return MemOperand(frame_pointer(),
kRegisterZero - register_index * kPointerSize);
}
void RegExpMacroAssemblerMIPS::CheckPosition(int cp_offset,
Label* on_outside_input) {
BranchOrBacktrack(on_outside_input,
ge,
current_input_offset(),
Operand(-cp_offset * char_size()));
}
void RegExpMacroAssemblerMIPS::BranchOrBacktrack(Label* to,
Condition condition,
Register rs,
const Operand& rt) {
if (condition == al) { // Unconditional.
if (to == NULL) {
Backtrack();
return;
}
__ jmp(to);
return;
}
if (to == NULL) {
__ Branch(&backtrack_label_, condition, rs, rt);
return;
}
__ Branch(to, condition, rs, rt);
}
void RegExpMacroAssemblerMIPS::SafeCall(Label* to, Condition cond, Register rs,
const Operand& rt) {
__ BranchAndLink(to, cond, rs, rt);
}
void RegExpMacroAssemblerMIPS::SafeReturn() {
__ pop(ra);
__ Addu(t5, ra, Operand(masm_->CodeObject()));
__ Jump(t5);
}
void RegExpMacroAssemblerMIPS::SafeCallTarget(Label* name) {
__ bind(name);
__ Subu(ra, ra, Operand(masm_->CodeObject()));
__ push(ra);
}
void RegExpMacroAssemblerMIPS::Push(Register source) {
ASSERT(!source.is(backtrack_stackpointer()));
__ Addu(backtrack_stackpointer(),
backtrack_stackpointer(),
Operand(-kPointerSize));
__ sw(source, MemOperand(backtrack_stackpointer()));
}
void RegExpMacroAssemblerMIPS::Pop(Register target) {
ASSERT(!target.is(backtrack_stackpointer()));
__ lw(target, MemOperand(backtrack_stackpointer()));
__ Addu(backtrack_stackpointer(), backtrack_stackpointer(), kPointerSize);
}
void RegExpMacroAssemblerMIPS::CheckPreemption() {
// Check for preemption.
ExternalReference stack_limit =
ExternalReference::address_of_stack_limit(masm_->isolate());
__ li(a0, Operand(stack_limit));
__ lw(a0, MemOperand(a0));
SafeCall(&check_preempt_label_, ls, sp, Operand(a0));
}
void RegExpMacroAssemblerMIPS::CheckStackLimit() {
ExternalReference stack_limit =
ExternalReference::address_of_regexp_stack_limit(masm_->isolate());
__ li(a0, Operand(stack_limit));
__ lw(a0, MemOperand(a0));
SafeCall(&stack_overflow_label_, ls, backtrack_stackpointer(), Operand(a0));
}
void RegExpMacroAssemblerMIPS::CallCFunctionUsingStub(
ExternalReference function,
int num_arguments) {
// Must pass all arguments in registers. The stub pushes on the stack.
ASSERT(num_arguments <= 4);
__ li(code_pointer(), Operand(function));
RegExpCEntryStub stub;
__ CallStub(&stub);
if (OS::ActivationFrameAlignment() != 0) {
__ lw(sp, MemOperand(sp, 16));
}
__ li(code_pointer(), Operand(masm_->CodeObject()), CONSTANT_SIZE);
}
void RegExpMacroAssemblerMIPS::LoadCurrentCharacterUnchecked(int cp_offset,
int characters) {
Register offset = current_input_offset();
if (cp_offset != 0) {
__ Addu(a0, current_input_offset(), Operand(cp_offset * char_size()));
offset = a0;
}
// We assume that we cannot do unaligned loads on MIPS, so this function
// must only be used to load a single character at a time.
ASSERT(characters == 1);
__ Addu(t5, end_of_input_address(), Operand(offset));
if (mode_ == ASCII) {
__ lbu(current_character(), MemOperand(t5, 0));
} else {
ASSERT(mode_ == UC16);
__ lhu(current_character(), MemOperand(t5, 0));
}
}
void RegExpCEntryStub::Generate(MacroAssembler* masm_) {
int stack_alignment = OS::ActivationFrameAlignment();
if (stack_alignment < kPointerSize) stack_alignment = kPointerSize;
// Stack is already aligned for call, so decrement by alignment
// to make room for storing the return address.
__ Subu(sp, sp, Operand(stack_alignment + kCArgsSlotsSize));
const int return_address_offset = kCArgsSlotsSize;
__ Addu(a0, sp, return_address_offset);
__ sw(ra, MemOperand(a0, 0));
__ mov(t9, t1);
__ Call(t9);
__ lw(ra, MemOperand(sp, return_address_offset));
__ Addu(sp, sp, Operand(stack_alignment + kCArgsSlotsSize));
__ Jump(ra);
}
#undef __
#endif // V8_INTERPRETED_REGEXP
}} // namespace v8::internal
#endif // V8_TARGET_ARCH_MIPS