// Copyright 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 "code-stubs.h"
#include "regexp-stack.h"
#include "macro-assembler.h"
#include "regexp-macro-assembler.h"
#include "arm/macro-assembler-arm.h"
#include "arm/regexp-macro-assembler-arm.h"
namespace v8 {
namespace internal {
#ifdef V8_NATIVE_REGEXP
/*
* This assembler uses the following register assignment convention
* - r5 : Pointer to current code object (Code*) including heap object tag.
* - r6 : Current position in input, as negative offset from end of string.
* Please notice that this is the byte offset, not the character offset!
* - r7 : Currently loaded character. Must be loaded using
* LoadCurrentCharacter before using any of the dispatch methods.
* - r8 : points to tip of backtrack stack
* - r9 : Unused, might be used by C code and expected unchanged.
* - r10 : End of input (points to byte after last character in input).
* - r11 : Frame pointer. Used to access arguments, local variables and
* RegExp registers.
* - r12 : IP register, used by assembler. Very volatile.
* - r13/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:
* - 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).
* --- sp when called ---
* - link address
* - backup of registers r4..r11
* - end of input (Address of end of string)
* - start of input (Address of first character in string)
* - start index (character index of start)
* --- frame pointer ----
* - void* input_string (location of a handle containing the string)
* - Offset of location before start of input (effectively character
* position -1). Used to initialize capture registers to a non-position.
* - At start (if 1, we are starting at the start of the
* string, otherwise 0)
* - 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, by calling the code entry as cast to a function with the signature:
* int (*match)(String* input_string,
* int start_index,
* Address start,
* Address end,
* int* capture_output_array,
* bool at_start,
* byte* stack_area_base,
* bool direct_call)
* The call is performed by NativeRegExpMacroAssembler::Execute()
* (in regexp-macro-assembler.cc).
*/
#define __ ACCESS_MASM(masm_)
RegExpMacroAssemblerARM::RegExpMacroAssemblerARM(
Mode mode,
int registers_to_save)
: masm_(new MacroAssembler(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_() {
ASSERT_EQ(0, registers_to_save % 2);
__ jmp(&entry_label_); // We'll write the entry code later.
EmitBacktrackConstantPool();
__ bind(&start_label_); // And then continue from here.
}
RegExpMacroAssemblerARM::~RegExpMacroAssemblerARM() {
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 RegExpMacroAssemblerARM::stack_limit_slack() {
return RegExpStack::kStackLimitSlack;
}
void RegExpMacroAssemblerARM::AdvanceCurrentPosition(int by) {
if (by != 0) {
Label inside_string;
__ add(current_input_offset(),
current_input_offset(), Operand(by * char_size()));
}
}
void RegExpMacroAssemblerARM::AdvanceRegister(int reg, int by) {
ASSERT(reg >= 0);
ASSERT(reg < num_registers_);
if (by != 0) {
__ ldr(r0, register_location(reg));
__ add(r0, r0, Operand(by));
__ str(r0, register_location(reg));
}
}
void RegExpMacroAssemblerARM::Backtrack() {
CheckPreemption();
// Pop Code* offset from backtrack stack, add Code* and jump to location.
Pop(r0);
__ add(pc, r0, Operand(r5));
}
void RegExpMacroAssemblerARM::Bind(Label* label) {
__ bind(label);
}
void RegExpMacroAssemblerARM::CheckCharacter(uint32_t c, Label* on_equal) {
__ cmp(current_character(), Operand(c));
BranchOrBacktrack(eq, on_equal);
}
void RegExpMacroAssemblerARM::CheckCharacterGT(uc16 limit, Label* on_greater) {
__ cmp(current_character(), Operand(limit));
BranchOrBacktrack(gt, on_greater);
}
void RegExpMacroAssemblerARM::CheckAtStart(Label* on_at_start) {
Label not_at_start;
// Did we start the match at the start of the string at all?
__ ldr(r0, MemOperand(frame_pointer(), kAtStart));
__ cmp(r0, Operand(0));
BranchOrBacktrack(eq, ¬_at_start);
// If we did, are we still at the start of the input?
__ ldr(r1, MemOperand(frame_pointer(), kInputStart));
__ add(r0, end_of_input_address(), Operand(current_input_offset()));
__ cmp(r0, r1);
BranchOrBacktrack(eq, on_at_start);
__ bind(¬_at_start);
}
void RegExpMacroAssemblerARM::CheckNotAtStart(Label* on_not_at_start) {
// Did we start the match at the start of the string at all?
__ ldr(r0, MemOperand(frame_pointer(), kAtStart));
__ cmp(r0, Operand(0));
BranchOrBacktrack(eq, on_not_at_start);
// If we did, are we still at the start of the input?
__ ldr(r1, MemOperand(frame_pointer(), kInputStart));
__ add(r0, end_of_input_address(), Operand(current_input_offset()));
__ cmp(r0, r1);
BranchOrBacktrack(ne, on_not_at_start);
}
void RegExpMacroAssemblerARM::CheckCharacterLT(uc16 limit, Label* on_less) {
__ cmp(current_character(), Operand(limit));
BranchOrBacktrack(lt, on_less);
}
void RegExpMacroAssemblerARM::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);
}
__ add(r0, end_of_input_address(), Operand(current_input_offset()));
if (cp_offset != 0) {
int byte_offset = cp_offset * char_size();
__ add(r0, r0, Operand(byte_offset));
}
// r0 : Address of characters to match against str.
int stored_high_byte = 0;
for (int i = 0; i < str.length(); i++) {
if (mode_ == ASCII) {
__ ldrb(r1, MemOperand(r0, char_size(), PostIndex));
ASSERT(str[i] <= String::kMaxAsciiCharCode);
__ cmp(r1, Operand(str[i]));
} else {
__ ldrh(r1, MemOperand(r0, char_size(), PostIndex));
uc16 match_char = str[i];
int match_high_byte = (match_char >> 8);
if (match_high_byte == 0) {
__ cmp(r1, Operand(str[i]));
} else {
if (match_high_byte != stored_high_byte) {
__ mov(r2, Operand(match_high_byte));
stored_high_byte = match_high_byte;
}
__ add(r3, r2, Operand(match_char & 0xff));
__ cmp(r1, r3);
}
}
BranchOrBacktrack(ne, on_failure);
}
}
void RegExpMacroAssemblerARM::CheckGreedyLoop(Label* on_equal) {
__ ldr(r0, MemOperand(backtrack_stackpointer(), 0));
__ cmp(current_input_offset(), r0);
__ add(backtrack_stackpointer(),
backtrack_stackpointer(), Operand(kPointerSize), LeaveCC, eq);
BranchOrBacktrack(eq, on_equal);
}
void RegExpMacroAssemblerARM::CheckNotBackReferenceIgnoreCase(
int start_reg,
Label* on_no_match) {
Label fallthrough;
__ ldr(r0, register_location(start_reg)); // Index of start of capture
__ ldr(r1, register_location(start_reg + 1)); // Index of end of capture
__ sub(r1, r1, r0, SetCC); // Length of capture.
// If length is zero, either the capture is empty or it is not participating.
// In either case succeed immediately.
__ b(eq, &fallthrough);
// Check that there are enough characters left in the input.
__ cmn(r1, Operand(current_input_offset()));
BranchOrBacktrack(gt, on_no_match);
if (mode_ == ASCII) {
Label success;
Label fail;
Label loop_check;
// r0 - offset of start of capture
// r1 - length of capture
__ add(r0, r0, Operand(end_of_input_address()));
__ add(r2, end_of_input_address(), Operand(current_input_offset()));
__ add(r1, r0, Operand(r1));
// r0 - Address of start of capture.
// r1 - Address of end of capture
// r2 - Address of current input position.
Label loop;
__ bind(&loop);
__ ldrb(r3, MemOperand(r0, char_size(), PostIndex));
__ ldrb(r4, MemOperand(r2, char_size(), PostIndex));
__ cmp(r4, r3);
__ b(eq, &loop_check);
// Mismatch, try case-insensitive match (converting letters to lower-case).
__ orr(r3, r3, Operand(0x20)); // Convert capture character to lower-case.
__ orr(r4, r4, Operand(0x20)); // Also convert input character.
__ cmp(r4, r3);
__ b(ne, &fail);
__ sub(r3, r3, Operand('a'));
__ cmp(r3, Operand('z' - 'a')); // Is r3 a lowercase letter?
__ b(hi, &fail);
__ bind(&loop_check);
__ cmp(r0, r1);
__ b(lt, &loop);
__ jmp(&success);
__ bind(&fail);
BranchOrBacktrack(al, on_no_match);
__ bind(&success);
// Compute new value of character position after the matched part.
__ sub(current_input_offset(), r2, end_of_input_address());
} else {
ASSERT(mode_ == UC16);
int argument_count = 3;
FrameAlign(argument_count, r2);
// r0 - offset of start of capture
// r1 - length of capture
// Put arguments into arguments registers.
// Parameters are
// r0: Address byte_offset1 - Address captured substring's start.
// r1: Address byte_offset2 - Address of current character position.
// r2: size_t byte_length - length of capture in bytes(!)
// Address of start of capture.
__ add(r0, r0, Operand(end_of_input_address()));
// Length of capture.
__ mov(r2, Operand(r1));
// Save length in callee-save register for use on return.
__ mov(r4, Operand(r1));
// Address of current input position.
__ add(r1, current_input_offset(), Operand(end_of_input_address()));
ExternalReference function =
ExternalReference::re_case_insensitive_compare_uc16();
CallCFunction(function, argument_count);
// Check if function returned non-zero for success or zero for failure.
__ cmp(r0, Operand(0));
BranchOrBacktrack(eq, on_no_match);
// On success, increment position by length of capture.
__ add(current_input_offset(), current_input_offset(), Operand(r4));
}
__ bind(&fallthrough);
}
void RegExpMacroAssemblerARM::CheckNotBackReference(
int start_reg,
Label* on_no_match) {
Label fallthrough;
Label success;
// Find length of back-referenced capture.
__ ldr(r0, register_location(start_reg));
__ ldr(r1, register_location(start_reg + 1));
__ sub(r1, r1, r0, SetCC); // Length to check.
// Succeed on empty capture (including no capture).
__ b(eq, &fallthrough);
// Check that there are enough characters left in the input.
__ cmn(r1, Operand(current_input_offset()));
BranchOrBacktrack(gt, on_no_match);
// Compute pointers to match string and capture string
__ add(r0, r0, Operand(end_of_input_address()));
__ add(r2, end_of_input_address(), Operand(current_input_offset()));
__ add(r1, r1, Operand(r0));
Label loop;
__ bind(&loop);
if (mode_ == ASCII) {
__ ldrb(r3, MemOperand(r0, char_size(), PostIndex));
__ ldrb(r4, MemOperand(r2, char_size(), PostIndex));
} else {
ASSERT(mode_ == UC16);
__ ldrh(r3, MemOperand(r0, char_size(), PostIndex));
__ ldrh(r4, MemOperand(r2, char_size(), PostIndex));
}
__ cmp(r3, r4);
BranchOrBacktrack(ne, on_no_match);
__ cmp(r0, r1);
__ b(lt, &loop);
// Move current character position to position after match.
__ sub(current_input_offset(), r2, end_of_input_address());
__ bind(&fallthrough);
}
void RegExpMacroAssemblerARM::CheckNotRegistersEqual(int reg1,
int reg2,
Label* on_not_equal) {
__ ldr(r0, register_location(reg1));
__ ldr(r1, register_location(reg2));
__ cmp(r0, r1);
BranchOrBacktrack(ne, on_not_equal);
}
void RegExpMacroAssemblerARM::CheckNotCharacter(uint32_t c,
Label* on_not_equal) {
__ cmp(current_character(), Operand(c));
BranchOrBacktrack(ne, on_not_equal);
}
void RegExpMacroAssemblerARM::CheckCharacterAfterAnd(uint32_t c,
uint32_t mask,
Label* on_equal) {
__ and_(r0, current_character(), Operand(mask));
__ cmp(r0, Operand(c));
BranchOrBacktrack(eq, on_equal);
}
void RegExpMacroAssemblerARM::CheckNotCharacterAfterAnd(uint32_t c,
uint32_t mask,
Label* on_not_equal) {
__ and_(r0, current_character(), Operand(mask));
__ cmp(r0, Operand(c));
BranchOrBacktrack(ne, on_not_equal);
}
void RegExpMacroAssemblerARM::CheckNotCharacterAfterMinusAnd(
uc16 c,
uc16 minus,
uc16 mask,
Label* on_not_equal) {
ASSERT(minus < String::kMaxUC16CharCode);
__ sub(r0, current_character(), Operand(minus));
__ and_(r0, r0, Operand(mask));
__ cmp(r0, Operand(c));
BranchOrBacktrack(ne, on_not_equal);
}
bool RegExpMacroAssemblerARM::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;
__ cmp(current_character(), Operand(' '));
__ b(eq, &success);
// Check range 0x09..0x0d
__ sub(r0, current_character(), Operand('\t'));
__ cmp(r0, Operand('\r' - '\t'));
BranchOrBacktrack(hi, 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 ' '.
__ cmp(current_character(), Operand(' '));
BranchOrBacktrack(eq, on_no_match);
__ sub(r0, current_character(), Operand('\t'));
__ cmp(r0, Operand('\r' - '\t'));
BranchOrBacktrack(ls, on_no_match);
return true;
}
return false;
case 'd':
// Match ASCII digits ('0'..'9')
__ sub(r0, current_character(), Operand('0'));
__ cmp(current_character(), Operand('9' - '0'));
BranchOrBacktrack(hi, on_no_match);
return true;
case 'D':
// Match non ASCII-digits
__ sub(r0, current_character(), Operand('0'));
__ cmp(r0, Operand('9' - '0'));
BranchOrBacktrack(ls, on_no_match);
return true;
case '.': {
// Match non-newlines (not 0x0a('\n'), 0x0d('\r'), 0x2028 and 0x2029)
__ eor(r0, current_character(), Operand(0x01));
// See if current character is '\n'^1 or '\r'^1, i.e., 0x0b or 0x0c
__ sub(r0, r0, Operand(0x0b));
__ cmp(r0, Operand(0x0c - 0x0b));
BranchOrBacktrack(ls, 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(r0, r0, Operand(0x2028 - 0x0b));
__ cmp(r0, Operand(1));
BranchOrBacktrack(ls, on_no_match);
}
return true;
}
case 'n': {
// Match newlines (0x0a('\n'), 0x0d('\r'), 0x2028 and 0x2029)
__ eor(r0, current_character(), Operand(0x01));
// See if current character is '\n'^1 or '\r'^1, i.e., 0x0b or 0x0c
__ sub(r0, r0, Operand(0x0b));
__ cmp(r0, Operand(0x0c - 0x0b));
if (mode_ == ASCII) {
BranchOrBacktrack(hi, on_no_match);
} else {
Label done;
__ b(ls, &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.
__ sub(r0, r0, Operand(0x2028 - 0x0b));
__ cmp(r0, Operand(1));
BranchOrBacktrack(hi, on_no_match);
__ bind(&done);
}
return true;
}
case 'w': {
if (mode_ != ASCII) {
// Table is 128 entries, so all ASCII characters can be tested.
__ cmp(current_character(), Operand('z'));
BranchOrBacktrack(hi, on_no_match);
}
ExternalReference map = ExternalReference::re_word_character_map();
__ mov(r0, Operand(map));
__ ldrb(r0, MemOperand(r0, current_character()));
__ tst(r0, Operand(r0));
BranchOrBacktrack(eq, on_no_match);
return true;
}
case 'W': {
Label done;
if (mode_ != ASCII) {
// Table is 128 entries, so all ASCII characters can be tested.
__ cmp(current_character(), Operand('z'));
__ b(hi, &done);
}
ExternalReference map = ExternalReference::re_word_character_map();
__ mov(r0, Operand(map));
__ ldrb(r0, MemOperand(r0, current_character()));
__ tst(r0, Operand(r0));
BranchOrBacktrack(ne, 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 RegExpMacroAssemblerARM::Fail() {
__ mov(r0, Operand(FAILURE));
__ jmp(&exit_label_);
}
Handle<Object> RegExpMacroAssemblerARM::GetCode(Handle<String> source) {
// Finalize code - write the entry point code now we know how many
// registers we need.
// Entry code:
__ bind(&entry_label_);
// Push Link register.
// Push arguments
// Save callee-save registers.
// Start new stack frame.
// Order here should correspond to order of offset constants in header file.
RegList registers_to_retain = r4.bit() | r5.bit() | r6.bit() |
r7.bit() | r8.bit() | r9.bit() | r10.bit() | fp.bit();
RegList argument_registers = r0.bit() | r1.bit() | r2.bit() | r3.bit();
__ stm(db_w, sp, argument_registers | registers_to_retain | lr.bit());
// Set frame pointer just above the arguments.
__ add(frame_pointer(), sp, Operand(4 * kPointerSize));
__ push(r0); // Make room for "position - 1" constant (value is irrelevant).
__ push(r0); // Make room for "at start" constant (value is 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();
__ mov(r0, Operand(stack_limit));
__ ldr(r0, MemOperand(r0));
__ sub(r0, sp, r0, SetCC);
// Handle it if the stack pointer is already below the stack limit.
__ b(ls, &stack_limit_hit);
// Check if there is room for the variable number of registers above
// the stack limit.
__ cmp(r0, Operand(num_registers_ * kPointerSize));
__ b(hs, &stack_ok);
// Exit with OutOfMemory exception. There is not enough space on the stack
// for our working registers.
__ mov(r0, Operand(EXCEPTION));
__ jmp(&exit_label_);
__ bind(&stack_limit_hit);
CallCheckStackGuardState(r0);
__ cmp(r0, Operand(0));
// If returned value is non-zero, we exit with the returned value as result.
__ b(ne, &exit_label_);
__ bind(&stack_ok);
// Allocate space on stack for registers.
__ sub(sp, sp, Operand(num_registers_ * kPointerSize));
// Load string end.
__ ldr(end_of_input_address(), MemOperand(frame_pointer(), kInputEnd));
// Load input start.
__ ldr(r0, MemOperand(frame_pointer(), kInputStart));
// Find negative length (offset of start relative to end).
__ sub(current_input_offset(), r0, end_of_input_address());
// Set r0 to address of char before start of input
// (effectively string position -1).
__ sub(r0, current_input_offset(), Operand(char_size()));
// Store this value in a local variable, for use when clearing
// position registers.
__ str(r0, 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.
__ ldr(r1, MemOperand(frame_pointer(), kStartIndex));
__ tst(r1, Operand(r1));
__ mov(r1, Operand(1), LeaveCC, eq);
__ mov(r1, Operand(0), LeaveCC, ne);
__ str(r1, 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.
__ add(r1, frame_pointer(), Operand(kRegisterZero));
__ mov(r2, Operand(num_saved_registers_));
Label init_loop;
__ bind(&init_loop);
__ str(r0, MemOperand(r1, kPointerSize, NegPostIndex));
__ sub(r2, r2, Operand(1), SetCC);
__ b(ne, &init_loop);
}
// Initialize backtrack stack pointer.
__ ldr(backtrack_stackpointer(), MemOperand(frame_pointer(), kStackHighEnd));
// Initialize code pointer register
__ mov(code_pointer(), Operand(masm_->CodeObject()));
// Load previous char as initial value of current character register.
Label at_start;
__ ldr(r0, MemOperand(frame_pointer(), kAtStart));
__ cmp(r0, Operand(0));
__ b(ne, &at_start);
LoadCurrentCharacterUnchecked(-1, 1); // Load previous char.
__ jmp(&start_label_);
__ bind(&at_start);
__ mov(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
__ ldr(r1, MemOperand(frame_pointer(), kInputStart));
__ ldr(r0, MemOperand(frame_pointer(), kRegisterOutput));
__ sub(r1, end_of_input_address(), r1);
// r1 is length of input in bytes.
if (mode_ == UC16) {
__ mov(r1, Operand(r1, LSR, 1));
}
// r1 is length of input 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) {
__ ldr(r2, register_location(i));
__ ldr(r3, register_location(i + 1));
if (mode_ == UC16) {
__ add(r2, r1, Operand(r2, ASR, 1));
__ add(r3, r1, Operand(r3, ASR, 1));
} else {
__ add(r2, r1, Operand(r2));
__ add(r3, r1, Operand(r3));
}
__ str(r2, MemOperand(r0, kPointerSize, PostIndex));
__ str(r3, MemOperand(r0, kPointerSize, PostIndex));
}
}
__ mov(r0, Operand(SUCCESS));
}
// Exit and return r0
__ bind(&exit_label_);
// Skip sp past regexp registers and local variables..
__ mov(sp, frame_pointer());
// Restore registers r4..r11 and return (restoring lr to pc).
__ ldm(ia_w, sp, registers_to_retain | pc.bit());
// 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_);
CallCheckStackGuardState(r0);
__ cmp(r0, Operand(0));
// If returning non-zero, we should end execution with the given
// result as return value.
__ b(ne, &exit_label_);
// String might have moved: Reload end of string from frame.
__ ldr(end_of_input_address(), MemOperand(frame_pointer(), 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;
// Call GrowStack(backtrack_stackpointer())
int num_arguments = 2;
FrameAlign(num_arguments, r0);
__ mov(r0, backtrack_stackpointer());
__ add(r1, frame_pointer(), Operand(kStackHighEnd));
ExternalReference grow_stack =
ExternalReference::re_grow_stack();
CallCFunction(grow_stack, num_arguments);
// If return NULL, we have failed to grow the stack, and
// must exit with a stack-overflow exception.
__ cmp(r0, Operand(0));
__ b(eq, &exit_with_exception);
// Otherwise use return value as new stack pointer.
__ mov(backtrack_stackpointer(), r0);
// Restore saved registers and continue.
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(r0, Operand(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 RegExpMacroAssemblerARM::GoTo(Label* to) {
BranchOrBacktrack(al, to);
}
void RegExpMacroAssemblerARM::IfRegisterGE(int reg,
int comparand,
Label* if_ge) {
__ ldr(r0, register_location(reg));
__ cmp(r0, Operand(comparand));
BranchOrBacktrack(ge, if_ge);
}
void RegExpMacroAssemblerARM::IfRegisterLT(int reg,
int comparand,
Label* if_lt) {
__ ldr(r0, register_location(reg));
__ cmp(r0, Operand(comparand));
BranchOrBacktrack(lt, if_lt);
}
void RegExpMacroAssemblerARM::IfRegisterEqPos(int reg,
Label* if_eq) {
__ ldr(r0, register_location(reg));
__ cmp(r0, Operand(current_input_offset()));
BranchOrBacktrack(eq, if_eq);
}
RegExpMacroAssembler::IrregexpImplementation
RegExpMacroAssemblerARM::Implementation() {
return kARMImplementation;
}
void RegExpMacroAssemblerARM::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 RegExpMacroAssemblerARM::PopCurrentPosition() {
Pop(current_input_offset());
}
void RegExpMacroAssemblerARM::PopRegister(int register_index) {
Pop(r0);
__ str(r0, register_location(register_index));
}
static bool is_valid_memory_offset(int value) {
if (value < 0) value = -value;
return value < (1<<12);
}
void RegExpMacroAssemblerARM::PushBacktrack(Label* label) {
if (label->is_bound()) {
int target = label->pos();
__ mov(r0, Operand(target + Code::kHeaderSize - kHeapObjectTag));
} else {
int constant_offset = GetBacktrackConstantPoolEntry();
masm_->label_at_put(label, constant_offset);
// Reading pc-relative is based on the address 8 bytes ahead of
// the current opcode.
unsigned int offset_of_pc_register_read =
masm_->pc_offset() + Assembler::kPcLoadDelta;
int pc_offset_of_constant =
constant_offset - offset_of_pc_register_read;
ASSERT(pc_offset_of_constant < 0);
if (is_valid_memory_offset(pc_offset_of_constant)) {
masm_->BlockConstPoolBefore(masm_->pc_offset() + Assembler::kInstrSize);
__ ldr(r0, MemOperand(pc, pc_offset_of_constant));
} else {
// Not a 12-bit offset, so it needs to be loaded from the constant
// pool.
masm_->BlockConstPoolBefore(
masm_->pc_offset() + 2 * Assembler::kInstrSize);
__ mov(r0, Operand(pc_offset_of_constant + Assembler::kInstrSize));
__ ldr(r0, MemOperand(pc, r0));
}
}
Push(r0);
CheckStackLimit();
}
void RegExpMacroAssemblerARM::PushCurrentPosition() {
Push(current_input_offset());
}
void RegExpMacroAssemblerARM::PushRegister(int register_index,
StackCheckFlag check_stack_limit) {
__ ldr(r0, register_location(register_index));
Push(r0);
if (check_stack_limit) CheckStackLimit();
}
void RegExpMacroAssemblerARM::ReadCurrentPositionFromRegister(int reg) {
__ ldr(current_input_offset(), register_location(reg));
}
void RegExpMacroAssemblerARM::ReadStackPointerFromRegister(int reg) {
__ ldr(backtrack_stackpointer(), register_location(reg));
__ ldr(r0, MemOperand(frame_pointer(), kStackHighEnd));
__ add(backtrack_stackpointer(), backtrack_stackpointer(), Operand(r0));
}
void RegExpMacroAssemblerARM::SetRegister(int register_index, int to) {
ASSERT(register_index >= num_saved_registers_); // Reserved for positions!
__ mov(r0, Operand(to));
__ str(r0, register_location(register_index));
}
void RegExpMacroAssemblerARM::Succeed() {
__ jmp(&success_label_);
}
void RegExpMacroAssemblerARM::WriteCurrentPositionToRegister(int reg,
int cp_offset) {
if (cp_offset == 0) {
__ str(current_input_offset(), register_location(reg));
} else {
__ add(r0, current_input_offset(), Operand(cp_offset * char_size()));
__ str(r0, register_location(reg));
}
}
void RegExpMacroAssemblerARM::ClearRegisters(int reg_from, int reg_to) {
ASSERT(reg_from <= reg_to);
__ ldr(r0, MemOperand(frame_pointer(), kInputStartMinusOne));
for (int reg = reg_from; reg <= reg_to; reg++) {
__ str(r0, register_location(reg));
}
}
void RegExpMacroAssemblerARM::WriteStackPointerToRegister(int reg) {
__ ldr(r1, MemOperand(frame_pointer(), kStackHighEnd));
__ sub(r0, backtrack_stackpointer(), r1);
__ str(r0, register_location(reg));
}
// Private methods:
void RegExpMacroAssemblerARM::CallCheckStackGuardState(Register scratch) {
int num_arguments = 3;
FrameAlign(num_arguments, scratch);
// RegExp code frame pointer.
__ mov(r2, frame_pointer());
// Code* of self.
__ mov(r1, Operand(masm_->CodeObject()));
// r0 becomes return address pointer.
ExternalReference stack_guard_check =
ExternalReference::re_check_stack_guard_state();
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 RegExpMacroAssemblerARM::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;
}
MemOperand RegExpMacroAssemblerARM::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 RegExpMacroAssemblerARM::CheckPosition(int cp_offset,
Label* on_outside_input) {
__ cmp(current_input_offset(), Operand(-cp_offset * char_size()));
BranchOrBacktrack(ge, on_outside_input);
}
void RegExpMacroAssemblerARM::BranchOrBacktrack(Condition condition,
Label* to) {
if (condition == al) { // Unconditional.
if (to == NULL) {
Backtrack();
return;
}
__ jmp(to);
return;
}
if (to == NULL) {
__ b(condition, &backtrack_label_);
return;
}
__ b(condition, to);
}
void RegExpMacroAssemblerARM::SafeCall(Label* to, Condition cond) {
__ bl(to, cond);
}
void RegExpMacroAssemblerARM::SafeReturn() {
__ pop(lr);
__ add(pc, lr, Operand(masm_->CodeObject()));
}
void RegExpMacroAssemblerARM::SafeCallTarget(Label* name) {
__ bind(name);
__ sub(lr, lr, Operand(masm_->CodeObject()));
__ push(lr);
}
void RegExpMacroAssemblerARM::Push(Register source) {
ASSERT(!source.is(backtrack_stackpointer()));
__ str(source,
MemOperand(backtrack_stackpointer(), kPointerSize, NegPreIndex));
}
void RegExpMacroAssemblerARM::Pop(Register target) {
ASSERT(!target.is(backtrack_stackpointer()));
__ ldr(target,
MemOperand(backtrack_stackpointer(), kPointerSize, PostIndex));
}
void RegExpMacroAssemblerARM::CheckPreemption() {
// Check for preemption.
ExternalReference stack_limit =
ExternalReference::address_of_stack_limit();
__ mov(r0, Operand(stack_limit));
__ ldr(r0, MemOperand(r0));
__ cmp(sp, r0);
SafeCall(&check_preempt_label_, ls);
}
void RegExpMacroAssemblerARM::CheckStackLimit() {
ExternalReference stack_limit =
ExternalReference::address_of_regexp_stack_limit();
__ mov(r0, Operand(stack_limit));
__ ldr(r0, MemOperand(r0));
__ cmp(backtrack_stackpointer(), Operand(r0));
SafeCall(&stack_overflow_label_, ls);
}
void RegExpMacroAssemblerARM::EmitBacktrackConstantPool() {
__ CheckConstPool(false, false);
__ BlockConstPoolBefore(
masm_->pc_offset() + kBacktrackConstantPoolSize * Assembler::kInstrSize);
backtrack_constant_pool_offset_ = masm_->pc_offset();
for (int i = 0; i < kBacktrackConstantPoolSize; i++) {
__ emit(0);
}
backtrack_constant_pool_capacity_ = kBacktrackConstantPoolSize;
}
int RegExpMacroAssemblerARM::GetBacktrackConstantPoolEntry() {
while (backtrack_constant_pool_capacity_ > 0) {
int offset = backtrack_constant_pool_offset_;
backtrack_constant_pool_offset_ += kPointerSize;
backtrack_constant_pool_capacity_--;
if (masm_->pc_offset() - offset < 2 * KB) {
return offset;
}
}
Label new_pool_skip;
__ jmp(&new_pool_skip);
EmitBacktrackConstantPool();
__ bind(&new_pool_skip);
int offset = backtrack_constant_pool_offset_;
backtrack_constant_pool_offset_ += kPointerSize;
backtrack_constant_pool_capacity_--;
return offset;
}
void RegExpMacroAssemblerARM::FrameAlign(int num_arguments, Register scratch) {
int frameAlignment = OS::ActivationFrameAlignment();
// Up to four simple arguments are passed in registers r0..r3.
int stack_passed_arguments = (num_arguments <= 4) ? 0 : num_arguments - 4;
if (frameAlignment != 0) {
// Make stack end at alignment and make room for num_arguments - 4 words
// and the original value of sp.
__ mov(scratch, sp);
__ sub(sp, sp, Operand((stack_passed_arguments + 1) * kPointerSize));
ASSERT(IsPowerOf2(frameAlignment));
__ and_(sp, sp, Operand(-frameAlignment));
__ str(scratch, MemOperand(sp, stack_passed_arguments * kPointerSize));
} else {
__ sub(sp, sp, Operand(stack_passed_arguments * kPointerSize));
}
}
void RegExpMacroAssemblerARM::CallCFunction(ExternalReference function,
int num_arguments) {
__ mov(r5, Operand(function));
// Just call directly. The function called cannot cause a GC, or
// allow preemption, so the return address in the link register
// stays correct.
__ Call(r5);
int stack_passed_arguments = (num_arguments <= 4) ? 0 : num_arguments - 4;
if (OS::ActivationFrameAlignment() > kIntSize) {
__ ldr(sp, MemOperand(sp, stack_passed_arguments * kPointerSize));
} else {
__ add(sp, sp, Operand(stack_passed_arguments * sizeof(kPointerSize)));
}
__ mov(code_pointer(), Operand(masm_->CodeObject()));
}
void RegExpMacroAssemblerARM::CallCFunctionUsingStub(
ExternalReference function,
int num_arguments) {
// Must pass all arguments in registers. The stub pushes on the stack.
ASSERT(num_arguments <= 4);
__ mov(r5, Operand(function));
RegExpCEntryStub stub;
__ CallStub(&stub);
if (OS::ActivationFrameAlignment() != 0) {
__ ldr(sp, MemOperand(sp, 0));
}
__ mov(code_pointer(), Operand(masm_->CodeObject()));
}
void RegExpMacroAssemblerARM::LoadCurrentCharacterUnchecked(int cp_offset,
int characters) {
Register offset = current_input_offset();
if (cp_offset != 0) {
__ add(r0, current_input_offset(), Operand(cp_offset * char_size()));
offset = r0;
}
// We assume that we cannot do unaligned loads on ARM, so this function
// must only be used to load a single character at a time.
ASSERT(characters == 1);
if (mode_ == ASCII) {
__ ldrb(current_character(), MemOperand(end_of_input_address(), offset));
} else {
ASSERT(mode_ == UC16);
__ ldrh(current_character(), MemOperand(end_of_input_address(), offset));
}
}
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 link register.
__ str(lr, MemOperand(sp, stack_alignment, NegPreIndex));
__ mov(r0, sp);
__ Call(r5);
__ ldr(pc, MemOperand(sp, stack_alignment, PostIndex));
}
#undef __
#endif // V8_NATIVE_REGEXP
}} // namespace v8::internal