// 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_ARM) #include "unicode.h" #include "log.h" #include "code-stubs.h" #include "regexp-stack.h" #include "macro-assembler.h" #include "regexp-macro-assembler.h" #include "arm/regexp-macro-assembler-arm.h" namespace v8 { namespace internal { #ifndef V8_INTERPRETED_REGEXP /* * This assembler uses the following register assignment convention * - r4 : Temporarily stores the index of capture start after a matching pass * for a global regexp. * - 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: * - fp[56] Isolate* isolate (address of the current isolate) * - fp[52] direct_call (if 1, direct call from JavaScript code, * if 0, call through the runtime system). * - fp[48] stack_area_base (high end of the memory area to use as * backtracking stack). * - fp[44] capture array size (may fit multiple sets of matches) * - fp[40] int* capture_array (int[num_saved_registers_], for output). * - fp[36] secondary link/return address used by native call. * --- sp when called --- * - fp[32] return address (lr). * - fp[28] old frame pointer (r11). * - fp[0..24] backup of registers r4..r10. * --- 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] success counter (only for global regexps to count matches). * - fp[-24] Offset of location before start of input (effectively character * position -1). Used to initialize capture registers to a * non-position. * - fp[-28] At start (if 1, we are starting at the start of the * string, otherwise 0) * - fp[-32] 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 arm/simulator-arm.h. * When calling as a non-direct call (i.e., from C++ code), the return address * area is overwritten with the LR 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_) RegExpMacroAssemblerARM::RegExpMacroAssemblerARM( Mode mode, int registers_to_save, Zone* zone) : NativeRegExpMacroAssembler(zone), 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_() { 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) { __ 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(code_pointer())); } 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(), kStartIndex)); __ cmp(r0, Operand(0, RelocInfo::NONE)); BranchOrBacktrack(ne, ¬_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(), kStartIndex)); __ cmp(r0, Operand(0, RelocInfo::NONE)); BranchOrBacktrack(ne, 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 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 = 4; __ PrepareCallCFunction(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(!) // r3: Isolate* isolate // 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())); // Isolate. __ mov(r3, Operand(ExternalReference::isolate_address())); { AllowExternalCallThatCantCauseGC scope(masm_); ExternalReference function = ExternalReference::re_case_insensitive_compare_uc16(masm_->isolate()); __ CallCFunction(function, argument_count); } // Check if function returned non-zero for success or zero for failure. __ cmp(r0, Operand(0, RelocInfo::NONE)); 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::CheckNotCharacter(unsigned 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) { if (c == 0) { __ tst(current_character(), Operand(mask)); } else { __ and_(r0, current_character(), Operand(mask)); __ cmp(r0, Operand(c)); } BranchOrBacktrack(eq, on_equal); } void RegExpMacroAssemblerARM::CheckNotCharacterAfterAnd(unsigned c, unsigned mask, Label* on_not_equal) { if (c == 0) { __ tst(current_character(), Operand(mask)); } else { __ 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::kMaxUtf16CodeUnit); __ sub(r0, current_character(), Operand(minus)); __ and_(r0, r0, Operand(mask)); __ cmp(r0, Operand(c)); BranchOrBacktrack(ne, on_not_equal); } void RegExpMacroAssemblerARM::CheckCharacterInRange( uc16 from, uc16 to, Label* on_in_range) { __ sub(r0, current_character(), Operand(from)); __ cmp(r0, Operand(to - from)); BranchOrBacktrack(ls, on_in_range); // Unsigned lower-or-same condition. } void RegExpMacroAssemblerARM::CheckCharacterNotInRange( uc16 from, uc16 to, Label* on_not_in_range) { __ sub(r0, current_character(), Operand(from)); __ cmp(r0, Operand(to - from)); BranchOrBacktrack(hi, on_not_in_range); // Unsigned higher condition. } void RegExpMacroAssemblerARM::CheckBitInTable( Handle table, Label* on_bit_set) { __ mov(r0, Operand(table)); if (mode_ != ASCII || kTableMask != String::kMaxAsciiCharCode) { __ and_(r1, current_character(), Operand(kTableSize - 1)); __ add(r1, r1, Operand(ByteArray::kHeaderSize - kHeapObjectTag)); } else { __ add(r1, current_character(), Operand(ByteArray::kHeaderSize - kHeapObjectTag)); } __ ldrb(r0, MemOperand(r0, r1)); __ cmp(r0, Operand(0)); BranchOrBacktrack(ne, on_bit_set); } 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())); __ cmp(r0, Operand(0)); 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())); __ cmp(r0, Operand(0)); 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 RegExpMacroAssemblerARM::GetCode(Handle source) { Label return_r0; // 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 = 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 in space for it if this is not a direct call // from generated code. __ add(frame_pointer(), sp, Operand(4 * kPointerSize)); __ mov(r0, Operand(0, RelocInfo::NONE)); __ push(r0); // Make room for success counter and initialize it to 0. __ push(r0); // Make room for "position - 1" 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(masm_->isolate()); __ 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(&return_r0); __ bind(&stack_limit_hit); CallCheckStackGuardState(r0); __ cmp(r0, Operand(0, RelocInfo::NONE)); // If returned value is non-zero, we exit with the returned value as result. __ b(ne, &return_r0); __ 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 the input string // (effectively string position -1). __ ldr(r1, MemOperand(frame_pointer(), kStartIndex)); __ sub(r0, current_input_offset(), Operand(char_size())); __ sub(r0, r0, Operand(r1, LSL, (mode_ == UC16) ? 1 : 0)); // Store this value in a local variable, for use when clearing // position registers. __ str(r0, MemOperand(frame_pointer(), kInputStartMinusOne)); // Initialize code pointer register __ mov(code_pointer(), Operand(masm_->CodeObject())); Label load_char_start_regexp, start_regexp; // Load newline if index is at start, previous character otherwise. __ cmp(r1, Operand(0, RelocInfo::NONE)); __ b(ne, &load_char_start_regexp); __ mov(current_character(), Operand('\n'), LeaveCC, eq); __ jmp(&start_regexp); // Global regexp restarts matching here. __ bind(&load_char_start_regexp); // Load previous char as initial value of current character register. LoadCurrentCharacterUnchecked(-1, 1); __ bind(&start_regexp); // Initialize on-stack registers. if (num_saved_registers_ > 0) { // Always is, if generated from a regexp. // Fill saved registers with initial value = start offset - 1 if (num_saved_registers_ > 8) { // 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); } else { for (int i = 0; i < num_saved_registers_; i++) { __ str(r0, register_location(i)); } } } // Initialize backtrack stack pointer. __ ldr(backtrack_stackpointer(), MemOperand(frame_pointer(), kStackHighEnd)); __ jmp(&start_label_); // Exit code: if (success_label_.is_linked()) { // Save captures when successful. __ bind(&success_label_); if (num_saved_registers_ > 0) { // copy captures to output __ ldr(r1, MemOperand(frame_pointer(), kInputStart)); __ ldr(r0, MemOperand(frame_pointer(), kRegisterOutput)); __ ldr(r2, MemOperand(frame_pointer(), kStartIndex)); __ 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. __ add(r1, r1, Operand(r2)); // r1 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) { __ ldr(r2, register_location(i)); __ ldr(r3, register_location(i + 1)); if (i == 0 && global_with_zero_length_check()) { // Keep capture start in r4 for the zero-length check later. __ mov(r4, r2); } 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)); } } if (global()) { // Restart matching if the regular expression is flagged as global. __ ldr(r0, MemOperand(frame_pointer(), kSuccessfulCaptures)); __ ldr(r1, MemOperand(frame_pointer(), kNumOutputRegisters)); __ ldr(r2, MemOperand(frame_pointer(), kRegisterOutput)); // Increment success counter. __ add(r0, r0, Operand(1)); __ str(r0, MemOperand(frame_pointer(), kSuccessfulCaptures)); // Capture results have been stored, so the number of remaining global // output registers is reduced by the number of stored captures. __ sub(r1, r1, Operand(num_saved_registers_)); // Check whether we have enough room for another set of capture results. __ cmp(r1, Operand(num_saved_registers_)); __ b(lt, &return_r0); __ str(r1, MemOperand(frame_pointer(), kNumOutputRegisters)); // Advance the location for output. __ add(r2, r2, Operand(num_saved_registers_ * kPointerSize)); __ str(r2, MemOperand(frame_pointer(), kRegisterOutput)); // Prepare r0 to initialize registers with its value in the next run. __ ldr(r0, MemOperand(frame_pointer(), kInputStartMinusOne)); if (global_with_zero_length_check()) { // Special case for zero-length matches. // r4: capture start index __ cmp(current_input_offset(), r4); // Not a zero-length match, restart. __ b(ne, &load_char_start_regexp); // Offset from the end is zero if we already reached the end. __ cmp(current_input_offset(), Operand(0)); __ b(eq, &exit_label_); // Advance current position after a zero-length match. __ add(current_input_offset(), current_input_offset(), Operand((mode_ == UC16) ? 2 : 1)); } __ b(&load_char_start_regexp); } else { __ mov(r0, Operand(SUCCESS)); } } // Exit and return r0 __ bind(&exit_label_); if (global()) { __ ldr(r0, MemOperand(frame_pointer(), kSuccessfulCaptures)); } __ bind(&return_r0); // 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, RelocInfo::NONE)); // If returning non-zero, we should end execution with the given // result as return value. __ b(ne, &return_r0); // 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(), &stack_base) static const int num_arguments = 3; __ PrepareCallCFunction(num_arguments, r0); __ mov(r0, backtrack_stackpointer()); __ add(r1, frame_pointer(), Operand(kStackHighEnd)); __ mov(r2, Operand(ExternalReference::isolate_address())); 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. __ cmp(r0, Operand(0, RelocInfo::NONE)); __ 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(&return_r0); } CodeDesc code_desc; masm_->GetCode(&code_desc); Handle code = FACTORY->NewCode(code_desc, Code::ComputeFlags(Code::REGEXP), masm_->CodeObject()); PROFILE(Isolate::Current(), RegExpCodeCreateEvent(*code, *source)); return Handle::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)) { Assembler::BlockConstPoolScope block_const_pool(masm_); __ ldr(r0, MemOperand(pc, pc_offset_of_constant)); } else { // Not a 12-bit offset, so it needs to be loaded from the constant // pool. Assembler::BlockConstPoolScope block_const_pool(masm_); __ 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::SetCurrentPositionFromEnd(int by) { Label after_position; __ cmp(current_input_offset(), Operand(-by * char_size())); __ b(ge, &after_position); __ mov(current_input_offset(), Operand(-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 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)); } bool RegExpMacroAssemblerARM::Succeed() { __ jmp(&success_label_); return global(); } 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) { static const int num_arguments = 3; __ PrepareCallCFunction(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(masm_->isolate()); CallCFunctionUsingStub(stack_guard_check, num_arguments); } // Helper function for reading a value out of a stack frame. template static T& frame_entry(Address re_frame, int frame_offset) { return reinterpret_cast(Memory::int32_at(re_frame + frame_offset)); } int RegExpMacroAssemblerARM::CheckStackGuardState(Address* return_address, Code* re_code, Address re_frame) { Isolate* isolate = frame_entry(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(re_frame, kDirectCall) == 1) { return RETRY; } // Prepare for possible GC. HandleScope handles(isolate); Handle code_handle(re_code); Handle subject(frame_entry(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 subject_tmp = subject; int slice_offset = 0; // Extract the underlying string and the slice offset. if (StringShape(*subject_tmp).IsCons()) { subject_tmp = Handle(ConsString::cast(*subject_tmp)->first()); } else if (StringShape(*subject_tmp).IsSliced()) { SlicedString* slice = SlicedString::cast(*subject_tmp); subject_tmp = Handle(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(re_frame, kInputStart); // Find the current start address of the same character at the current string // position. int start_index = frame_entry(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(re_frame, kInputEnd); int byte_length = static_cast(end_address - start_address); frame_entry(re_frame, kInputString) = *subject; frame_entry(re_frame, kInputStart) = new_address; frame_entry(re_frame, kInputEnd) = new_address + byte_length; } else if (frame_entry(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(re_frame, kInputString) = *subject; } 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(masm_->isolate()); __ 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(masm_->isolate()); __ 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); Assembler::BlockConstPoolScope block_const_pool(masm_); 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::CallCFunctionUsingStub( ExternalReference function, int num_arguments) { // Must pass all arguments in registers. The stub pushes on the stack. ASSERT(num_arguments <= 4); __ mov(code_pointer(), Operand(function)); RegExpCEntryStub stub; __ CallStub(&stub); if (OS::ActivationFrameAlignment() != 0) { __ ldr(sp, MemOperand(sp, 0)); } __ mov(code_pointer(), Operand(masm_->CodeObject())); } bool RegExpMacroAssemblerARM::CanReadUnaligned() { return CpuFeatures::IsSupported(UNALIGNED_ACCESSES) && !slow_safe(); } void RegExpMacroAssemblerARM::LoadCurrentCharacterUnchecked(int cp_offset, int characters) { Register offset = current_input_offset(); if (cp_offset != 0) { // r4 is not being used to store the capture start index at this point. __ add(r4, current_input_offset(), Operand(cp_offset * char_size())); offset = r4; } // The ldr, str, ldrh, strh instructions can do unaligned accesses, if the CPU // and the operating system running on the target allow it. // If unaligned load/stores are not supported then this function must only // be used to load a single character at a time. if (!CanReadUnaligned()) { ASSERT(characters == 1); } if (mode_ == ASCII) { if (characters == 4) { __ ldr(current_character(), MemOperand(end_of_input_address(), offset)); } else if (characters == 2) { __ ldrh(current_character(), MemOperand(end_of_input_address(), offset)); } else { ASSERT(characters == 1); __ ldrb(current_character(), MemOperand(end_of_input_address(), offset)); } } else { ASSERT(mode_ == UC16); if (characters == 2) { __ ldr(current_character(), MemOperand(end_of_input_address(), offset)); } else { ASSERT(characters == 1); __ 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_INTERPRETED_REGEXP }} // namespace v8::internal #endif // V8_TARGET_ARCH_ARM