// Copyright 2006-2009 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 "bootstrapper.h"
#include "codegen-inl.h"
#include "debug.h"
#include "runtime.h"
namespace v8 {
namespace internal {
MacroAssembler::MacroAssembler(void* buffer, int size)
: Assembler(buffer, size),
generating_stub_(false),
allow_stub_calls_(true),
code_object_(Heap::undefined_value()) {
}
// We always generate arm code, never thumb code, even if V8 is compiled to
// thumb, so we require inter-working support
#if defined(__thumb__) && !defined(USE_THUMB_INTERWORK)
#error "flag -mthumb-interwork missing"
#endif
// We do not support thumb inter-working with an arm architecture not supporting
// the blx instruction (below v5t). If you know what CPU you are compiling for
// you can use -march=armv7 or similar.
#if defined(USE_THUMB_INTERWORK) && !defined(CAN_USE_THUMB_INSTRUCTIONS)
# error "For thumb inter-working we require an architecture which supports blx"
#endif
// Using blx may yield better code, so use it when required or when available
#if defined(USE_THUMB_INTERWORK) || defined(CAN_USE_ARMV5_INSTRUCTIONS)
#define USE_BLX 1
#endif
// Using bx does not yield better code, so use it only when required
#if defined(USE_THUMB_INTERWORK)
#define USE_BX 1
#endif
void MacroAssembler::Jump(Register target, Condition cond) {
#if USE_BX
bx(target, cond);
#else
mov(pc, Operand(target), LeaveCC, cond);
#endif
}
void MacroAssembler::Jump(intptr_t target, RelocInfo::Mode rmode,
Condition cond) {
#if USE_BX
mov(ip, Operand(target, rmode), LeaveCC, cond);
bx(ip, cond);
#else
mov(pc, Operand(target, rmode), LeaveCC, cond);
#endif
}
void MacroAssembler::Jump(byte* target, RelocInfo::Mode rmode,
Condition cond) {
ASSERT(!RelocInfo::IsCodeTarget(rmode));
Jump(reinterpret_cast<intptr_t>(target), rmode, cond);
}
void MacroAssembler::Jump(Handle<Code> code, RelocInfo::Mode rmode,
Condition cond) {
ASSERT(RelocInfo::IsCodeTarget(rmode));
// 'code' is always generated ARM code, never THUMB code
Jump(reinterpret_cast<intptr_t>(code.location()), rmode, cond);
}
void MacroAssembler::Call(Register target, Condition cond) {
#if USE_BLX
blx(target, cond);
#else
// set lr for return at current pc + 8
mov(lr, Operand(pc), LeaveCC, cond);
mov(pc, Operand(target), LeaveCC, cond);
#endif
}
void MacroAssembler::Call(intptr_t target, RelocInfo::Mode rmode,
Condition cond) {
// Set lr for return at current pc + 8.
mov(lr, Operand(pc), LeaveCC, cond);
// Emit a ldr<cond> pc, [pc + offset of target in constant pool].
mov(pc, Operand(target, rmode), LeaveCC, cond);
// If USE_BLX is defined, we could emit a 'mov ip, target', followed by a
// 'blx ip'; however, the code would not be shorter than the above sequence
// and the target address of the call would be referenced by the first
// instruction rather than the second one, which would make it harder to patch
// (two instructions before the return address, instead of one).
ASSERT(kCallTargetAddressOffset == kInstrSize);
}
void MacroAssembler::Call(byte* target, RelocInfo::Mode rmode,
Condition cond) {
ASSERT(!RelocInfo::IsCodeTarget(rmode));
Call(reinterpret_cast<intptr_t>(target), rmode, cond);
}
void MacroAssembler::Call(Handle<Code> code, RelocInfo::Mode rmode,
Condition cond) {
ASSERT(RelocInfo::IsCodeTarget(rmode));
// 'code' is always generated ARM code, never THUMB code
Call(reinterpret_cast<intptr_t>(code.location()), rmode, cond);
}
void MacroAssembler::Ret(Condition cond) {
#if USE_BX
bx(lr, cond);
#else
mov(pc, Operand(lr), LeaveCC, cond);
#endif
}
void MacroAssembler::StackLimitCheck(Label* on_stack_overflow) {
LoadRoot(ip, Heap::kStackLimitRootIndex);
cmp(sp, Operand(ip));
b(lo, on_stack_overflow);
}
void MacroAssembler::Drop(int count, Condition cond) {
if (count > 0) {
add(sp, sp, Operand(count * kPointerSize), LeaveCC, cond);
}
}
void MacroAssembler::Call(Label* target) {
bl(target);
}
void MacroAssembler::Move(Register dst, Handle<Object> value) {
mov(dst, Operand(value));
}
void MacroAssembler::SmiJumpTable(Register index, Vector<Label*> targets) {
// Empty the const pool.
CheckConstPool(true, true);
add(pc, pc, Operand(index,
LSL,
assembler::arm::Instr::kInstrSizeLog2 - kSmiTagSize));
BlockConstPoolBefore(pc_offset() + (targets.length() + 1) * kInstrSize);
nop(); // Jump table alignment.
for (int i = 0; i < targets.length(); i++) {
b(targets[i]);
}
}
void MacroAssembler::LoadRoot(Register destination,
Heap::RootListIndex index,
Condition cond) {
ldr(destination, MemOperand(roots, index << kPointerSizeLog2), cond);
}
// Will clobber 4 registers: object, offset, scratch, ip. The
// register 'object' contains a heap object pointer. The heap object
// tag is shifted away.
void MacroAssembler::RecordWrite(Register object, Register offset,
Register scratch) {
// The compiled code assumes that record write doesn't change the
// context register, so we check that none of the clobbered
// registers are cp.
ASSERT(!object.is(cp) && !offset.is(cp) && !scratch.is(cp));
// This is how much we shift the remembered set bit offset to get the
// offset of the word in the remembered set. We divide by kBitsPerInt (32,
// shift right 5) and then multiply by kIntSize (4, shift left 2).
const int kRSetWordShift = 3;
Label fast, done;
// First, test that the object is not in the new space. We cannot set
// remembered set bits in the new space.
// object: heap object pointer (with tag)
// offset: offset to store location from the object
and_(scratch, object, Operand(ExternalReference::new_space_mask()));
cmp(scratch, Operand(ExternalReference::new_space_start()));
b(eq, &done);
// Compute the bit offset in the remembered set.
// object: heap object pointer (with tag)
// offset: offset to store location from the object
mov(ip, Operand(Page::kPageAlignmentMask)); // load mask only once
and_(scratch, object, Operand(ip)); // offset into page of the object
add(offset, scratch, Operand(offset)); // add offset into the object
mov(offset, Operand(offset, LSR, kObjectAlignmentBits));
// Compute the page address from the heap object pointer.
// object: heap object pointer (with tag)
// offset: bit offset of store position in the remembered set
bic(object, object, Operand(ip));
// If the bit offset lies beyond the normal remembered set range, it is in
// the extra remembered set area of a large object.
// object: page start
// offset: bit offset of store position in the remembered set
cmp(offset, Operand(Page::kPageSize / kPointerSize));
b(lt, &fast);
// Adjust the bit offset to be relative to the start of the extra
// remembered set and the start address to be the address of the extra
// remembered set.
sub(offset, offset, Operand(Page::kPageSize / kPointerSize));
// Load the array length into 'scratch' and multiply by four to get the
// size in bytes of the elements.
ldr(scratch, MemOperand(object, Page::kObjectStartOffset
+ FixedArray::kLengthOffset));
mov(scratch, Operand(scratch, LSL, kObjectAlignmentBits));
// Add the page header (including remembered set), array header, and array
// body size to the page address.
add(object, object, Operand(Page::kObjectStartOffset
+ FixedArray::kHeaderSize));
add(object, object, Operand(scratch));
bind(&fast);
// Get address of the rset word.
// object: start of the remembered set (page start for the fast case)
// offset: bit offset of store position in the remembered set
bic(scratch, offset, Operand(kBitsPerInt - 1)); // clear the bit offset
add(object, object, Operand(scratch, LSR, kRSetWordShift));
// Get bit offset in the rset word.
// object: address of remembered set word
// offset: bit offset of store position
and_(offset, offset, Operand(kBitsPerInt - 1));
ldr(scratch, MemOperand(object));
mov(ip, Operand(1));
orr(scratch, scratch, Operand(ip, LSL, offset));
str(scratch, MemOperand(object));
bind(&done);
// Clobber all input registers when running with the debug-code flag
// turned on to provoke errors.
if (FLAG_debug_code) {
mov(object, Operand(bit_cast<int32_t>(kZapValue)));
mov(offset, Operand(bit_cast<int32_t>(kZapValue)));
mov(scratch, Operand(bit_cast<int32_t>(kZapValue)));
}
}
void MacroAssembler::EnterFrame(StackFrame::Type type) {
// r0-r3: preserved
stm(db_w, sp, cp.bit() | fp.bit() | lr.bit());
mov(ip, Operand(Smi::FromInt(type)));
push(ip);
mov(ip, Operand(CodeObject()));
push(ip);
add(fp, sp, Operand(3 * kPointerSize)); // Adjust FP to point to saved FP.
}
void MacroAssembler::LeaveFrame(StackFrame::Type type) {
// r0: preserved
// r1: preserved
// r2: preserved
// Drop the execution stack down to the frame pointer and restore
// the caller frame pointer and return address.
mov(sp, fp);
ldm(ia_w, sp, fp.bit() | lr.bit());
}
void MacroAssembler::EnterExitFrame(ExitFrame::Mode mode) {
// Compute the argv pointer and keep it in a callee-saved register.
// r0 is argc.
add(r6, sp, Operand(r0, LSL, kPointerSizeLog2));
sub(r6, r6, Operand(kPointerSize));
// Compute callee's stack pointer before making changes and save it as
// ip register so that it is restored as sp register on exit, thereby
// popping the args.
// ip = sp + kPointerSize * #args;
add(ip, sp, Operand(r0, LSL, kPointerSizeLog2));
// Align the stack at this point. After this point we have 5 pushes,
// so in fact we have to unalign here! See also the assert on the
// alignment in AlignStack.
AlignStack(1);
// Push in reverse order: caller_fp, sp_on_exit, and caller_pc.
stm(db_w, sp, fp.bit() | ip.bit() | lr.bit());
mov(fp, Operand(sp)); // Setup new frame pointer.
mov(ip, Operand(CodeObject()));
push(ip); // Accessed from ExitFrame::code_slot.
// Save the frame pointer and the context in top.
mov(ip, Operand(ExternalReference(Top::k_c_entry_fp_address)));
str(fp, MemOperand(ip));
mov(ip, Operand(ExternalReference(Top::k_context_address)));
str(cp, MemOperand(ip));
// Setup argc and the builtin function in callee-saved registers.
mov(r4, Operand(r0));
mov(r5, Operand(r1));
#ifdef ENABLE_DEBUGGER_SUPPORT
// Save the state of all registers to the stack from the memory
// location. This is needed to allow nested break points.
if (mode == ExitFrame::MODE_DEBUG) {
// Use sp as base to push.
CopyRegistersFromMemoryToStack(sp, kJSCallerSaved);
}
#endif
}
void MacroAssembler::AlignStack(int offset) {
#if defined(V8_HOST_ARCH_ARM)
// Running on the real platform. Use the alignment as mandated by the local
// environment.
// Note: This will break if we ever start generating snapshots on one ARM
// platform for another ARM platform with a different alignment.
int activation_frame_alignment = OS::ActivationFrameAlignment();
#else // defined(V8_HOST_ARCH_ARM)
// If we are using the simulator then we should always align to the expected
// alignment. As the simulator is used to generate snapshots we do not know
// if the target platform will need alignment, so we will always align at
// this point here.
int activation_frame_alignment = 2 * kPointerSize;
#endif // defined(V8_HOST_ARCH_ARM)
if (activation_frame_alignment != kPointerSize) {
// This code needs to be made more general if this assert doesn't hold.
ASSERT(activation_frame_alignment == 2 * kPointerSize);
mov(r7, Operand(Smi::FromInt(0)));
tst(sp, Operand(activation_frame_alignment - offset));
push(r7, eq); // Conditional push instruction.
}
}
void MacroAssembler::LeaveExitFrame(ExitFrame::Mode mode) {
#ifdef ENABLE_DEBUGGER_SUPPORT
// Restore the memory copy of the registers by digging them out from
// the stack. This is needed to allow nested break points.
if (mode == ExitFrame::MODE_DEBUG) {
// This code intentionally clobbers r2 and r3.
const int kCallerSavedSize = kNumJSCallerSaved * kPointerSize;
const int kOffset = ExitFrameConstants::kCodeOffset - kCallerSavedSize;
add(r3, fp, Operand(kOffset));
CopyRegistersFromStackToMemory(r3, r2, kJSCallerSaved);
}
#endif
// Clear top frame.
mov(r3, Operand(0));
mov(ip, Operand(ExternalReference(Top::k_c_entry_fp_address)));
str(r3, MemOperand(ip));
// Restore current context from top and clear it in debug mode.
mov(ip, Operand(ExternalReference(Top::k_context_address)));
ldr(cp, MemOperand(ip));
#ifdef DEBUG
str(r3, MemOperand(ip));
#endif
// Pop the arguments, restore registers, and return.
mov(sp, Operand(fp)); // respect ABI stack constraint
ldm(ia, sp, fp.bit() | sp.bit() | pc.bit());
}
void MacroAssembler::InvokePrologue(const ParameterCount& expected,
const ParameterCount& actual,
Handle<Code> code_constant,
Register code_reg,
Label* done,
InvokeFlag flag) {
bool definitely_matches = false;
Label regular_invoke;
// Check whether the expected and actual arguments count match. If not,
// setup registers according to contract with ArgumentsAdaptorTrampoline:
// r0: actual arguments count
// r1: function (passed through to callee)
// r2: expected arguments count
// r3: callee code entry
// The code below is made a lot easier because the calling code already sets
// up actual and expected registers according to the contract if values are
// passed in registers.
ASSERT(actual.is_immediate() || actual.reg().is(r0));
ASSERT(expected.is_immediate() || expected.reg().is(r2));
ASSERT((!code_constant.is_null() && code_reg.is(no_reg)) || code_reg.is(r3));
if (expected.is_immediate()) {
ASSERT(actual.is_immediate());
if (expected.immediate() == actual.immediate()) {
definitely_matches = true;
} else {
mov(r0, Operand(actual.immediate()));
const int sentinel = SharedFunctionInfo::kDontAdaptArgumentsSentinel;
if (expected.immediate() == sentinel) {
// Don't worry about adapting arguments for builtins that
// don't want that done. Skip adaption code by making it look
// like we have a match between expected and actual number of
// arguments.
definitely_matches = true;
} else {
mov(r2, Operand(expected.immediate()));
}
}
} else {
if (actual.is_immediate()) {
cmp(expected.reg(), Operand(actual.immediate()));
b(eq, ®ular_invoke);
mov(r0, Operand(actual.immediate()));
} else {
cmp(expected.reg(), Operand(actual.reg()));
b(eq, ®ular_invoke);
}
}
if (!definitely_matches) {
if (!code_constant.is_null()) {
mov(r3, Operand(code_constant));
add(r3, r3, Operand(Code::kHeaderSize - kHeapObjectTag));
}
Handle<Code> adaptor =
Handle<Code>(Builtins::builtin(Builtins::ArgumentsAdaptorTrampoline));
if (flag == CALL_FUNCTION) {
Call(adaptor, RelocInfo::CODE_TARGET);
b(done);
} else {
Jump(adaptor, RelocInfo::CODE_TARGET);
}
bind(®ular_invoke);
}
}
void MacroAssembler::InvokeCode(Register code,
const ParameterCount& expected,
const ParameterCount& actual,
InvokeFlag flag) {
Label done;
InvokePrologue(expected, actual, Handle<Code>::null(), code, &done, flag);
if (flag == CALL_FUNCTION) {
Call(code);
} else {
ASSERT(flag == JUMP_FUNCTION);
Jump(code);
}
// Continue here if InvokePrologue does handle the invocation due to
// mismatched parameter counts.
bind(&done);
}
void MacroAssembler::InvokeCode(Handle<Code> code,
const ParameterCount& expected,
const ParameterCount& actual,
RelocInfo::Mode rmode,
InvokeFlag flag) {
Label done;
InvokePrologue(expected, actual, code, no_reg, &done, flag);
if (flag == CALL_FUNCTION) {
Call(code, rmode);
} else {
Jump(code, rmode);
}
// Continue here if InvokePrologue does handle the invocation due to
// mismatched parameter counts.
bind(&done);
}
void MacroAssembler::InvokeFunction(Register fun,
const ParameterCount& actual,
InvokeFlag flag) {
// Contract with called JS functions requires that function is passed in r1.
ASSERT(fun.is(r1));
Register expected_reg = r2;
Register code_reg = r3;
ldr(code_reg, FieldMemOperand(r1, JSFunction::kSharedFunctionInfoOffset));
ldr(cp, FieldMemOperand(r1, JSFunction::kContextOffset));
ldr(expected_reg,
FieldMemOperand(code_reg,
SharedFunctionInfo::kFormalParameterCountOffset));
ldr(code_reg,
MemOperand(code_reg, SharedFunctionInfo::kCodeOffset - kHeapObjectTag));
add(code_reg, code_reg, Operand(Code::kHeaderSize - kHeapObjectTag));
ParameterCount expected(expected_reg);
InvokeCode(code_reg, expected, actual, flag);
}
void MacroAssembler::InvokeFunction(JSFunction* function,
const ParameterCount& actual,
InvokeFlag flag) {
ASSERT(function->is_compiled());
// Get the function and setup the context.
mov(r1, Operand(Handle<JSFunction>(function)));
ldr(cp, FieldMemOperand(r1, JSFunction::kContextOffset));
// Invoke the cached code.
Handle<Code> code(function->code());
ParameterCount expected(function->shared()->formal_parameter_count());
InvokeCode(code, expected, actual, RelocInfo::CODE_TARGET, flag);
}
#ifdef ENABLE_DEBUGGER_SUPPORT
void MacroAssembler::SaveRegistersToMemory(RegList regs) {
ASSERT((regs & ~kJSCallerSaved) == 0);
// Copy the content of registers to memory location.
for (int i = 0; i < kNumJSCallerSaved; i++) {
int r = JSCallerSavedCode(i);
if ((regs & (1 << r)) != 0) {
Register reg = { r };
mov(ip, Operand(ExternalReference(Debug_Address::Register(i))));
str(reg, MemOperand(ip));
}
}
}
void MacroAssembler::RestoreRegistersFromMemory(RegList regs) {
ASSERT((regs & ~kJSCallerSaved) == 0);
// Copy the content of memory location to registers.
for (int i = kNumJSCallerSaved; --i >= 0;) {
int r = JSCallerSavedCode(i);
if ((regs & (1 << r)) != 0) {
Register reg = { r };
mov(ip, Operand(ExternalReference(Debug_Address::Register(i))));
ldr(reg, MemOperand(ip));
}
}
}
void MacroAssembler::CopyRegistersFromMemoryToStack(Register base,
RegList regs) {
ASSERT((regs & ~kJSCallerSaved) == 0);
// Copy the content of the memory location to the stack and adjust base.
for (int i = kNumJSCallerSaved; --i >= 0;) {
int r = JSCallerSavedCode(i);
if ((regs & (1 << r)) != 0) {
mov(ip, Operand(ExternalReference(Debug_Address::Register(i))));
ldr(ip, MemOperand(ip));
str(ip, MemOperand(base, 4, NegPreIndex));
}
}
}
void MacroAssembler::CopyRegistersFromStackToMemory(Register base,
Register scratch,
RegList regs) {
ASSERT((regs & ~kJSCallerSaved) == 0);
// Copy the content of the stack to the memory location and adjust base.
for (int i = 0; i < kNumJSCallerSaved; i++) {
int r = JSCallerSavedCode(i);
if ((regs & (1 << r)) != 0) {
mov(ip, Operand(ExternalReference(Debug_Address::Register(i))));
ldr(scratch, MemOperand(base, 4, PostIndex));
str(scratch, MemOperand(ip));
}
}
}
void MacroAssembler::DebugBreak() {
ASSERT(allow_stub_calls());
mov(r0, Operand(0));
mov(r1, Operand(ExternalReference(Runtime::kDebugBreak)));
CEntryStub ces(1);
Call(ces.GetCode(), RelocInfo::DEBUG_BREAK);
}
#endif
void MacroAssembler::PushTryHandler(CodeLocation try_location,
HandlerType type) {
// Adjust this code if not the case.
ASSERT(StackHandlerConstants::kSize == 4 * kPointerSize);
// The pc (return address) is passed in register lr.
if (try_location == IN_JAVASCRIPT) {
if (type == TRY_CATCH_HANDLER) {
mov(r3, Operand(StackHandler::TRY_CATCH));
} else {
mov(r3, Operand(StackHandler::TRY_FINALLY));
}
ASSERT(StackHandlerConstants::kStateOffset == 1 * kPointerSize
&& StackHandlerConstants::kFPOffset == 2 * kPointerSize
&& StackHandlerConstants::kPCOffset == 3 * kPointerSize);
stm(db_w, sp, r3.bit() | fp.bit() | lr.bit());
// Save the current handler as the next handler.
mov(r3, Operand(ExternalReference(Top::k_handler_address)));
ldr(r1, MemOperand(r3));
ASSERT(StackHandlerConstants::kNextOffset == 0);
push(r1);
// Link this handler as the new current one.
str(sp, MemOperand(r3));
} else {
// Must preserve r0-r4, r5-r7 are available.
ASSERT(try_location == IN_JS_ENTRY);
// The frame pointer does not point to a JS frame so we save NULL
// for fp. We expect the code throwing an exception to check fp
// before dereferencing it to restore the context.
mov(ip, Operand(0)); // To save a NULL frame pointer.
mov(r6, Operand(StackHandler::ENTRY));
ASSERT(StackHandlerConstants::kStateOffset == 1 * kPointerSize
&& StackHandlerConstants::kFPOffset == 2 * kPointerSize
&& StackHandlerConstants::kPCOffset == 3 * kPointerSize);
stm(db_w, sp, r6.bit() | ip.bit() | lr.bit());
// Save the current handler as the next handler.
mov(r7, Operand(ExternalReference(Top::k_handler_address)));
ldr(r6, MemOperand(r7));
ASSERT(StackHandlerConstants::kNextOffset == 0);
push(r6);
// Link this handler as the new current one.
str(sp, MemOperand(r7));
}
}
void MacroAssembler::PopTryHandler() {
ASSERT_EQ(0, StackHandlerConstants::kNextOffset);
pop(r1);
mov(ip, Operand(ExternalReference(Top::k_handler_address)));
add(sp, sp, Operand(StackHandlerConstants::kSize - kPointerSize));
str(r1, MemOperand(ip));
}
Register MacroAssembler::CheckMaps(JSObject* object, Register object_reg,
JSObject* holder, Register holder_reg,
Register scratch,
Label* miss) {
// Make sure there's no overlap between scratch and the other
// registers.
ASSERT(!scratch.is(object_reg) && !scratch.is(holder_reg));
// Keep track of the current object in register reg.
Register reg = object_reg;
int depth = 1;
// Check the maps in the prototype chain.
// Traverse the prototype chain from the object and do map checks.
while (object != holder) {
depth++;
// Only global objects and objects that do not require access
// checks are allowed in stubs.
ASSERT(object->IsJSGlobalProxy() || !object->IsAccessCheckNeeded());
// Get the map of the current object.
ldr(scratch, FieldMemOperand(reg, HeapObject::kMapOffset));
cmp(scratch, Operand(Handle<Map>(object->map())));
// Branch on the result of the map check.
b(ne, miss);
// Check access rights to the global object. This has to happen
// after the map check so that we know that the object is
// actually a global object.
if (object->IsJSGlobalProxy()) {
CheckAccessGlobalProxy(reg, scratch, miss);
// Restore scratch register to be the map of the object. In the
// new space case below, we load the prototype from the map in
// the scratch register.
ldr(scratch, FieldMemOperand(reg, HeapObject::kMapOffset));
}
reg = holder_reg; // from now the object is in holder_reg
JSObject* prototype = JSObject::cast(object->GetPrototype());
if (Heap::InNewSpace(prototype)) {
// The prototype is in new space; we cannot store a reference
// to it in the code. Load it from the map.
ldr(reg, FieldMemOperand(scratch, Map::kPrototypeOffset));
} else {
// The prototype is in old space; load it directly.
mov(reg, Operand(Handle<JSObject>(prototype)));
}
// Go to the next object in the prototype chain.
object = prototype;
}
// Check the holder map.
ldr(scratch, FieldMemOperand(reg, HeapObject::kMapOffset));
cmp(scratch, Operand(Handle<Map>(object->map())));
b(ne, miss);
// Log the check depth.
LOG(IntEvent("check-maps-depth", depth));
// Perform security check for access to the global object and return
// the holder register.
ASSERT(object == holder);
ASSERT(object->IsJSGlobalProxy() || !object->IsAccessCheckNeeded());
if (object->IsJSGlobalProxy()) {
CheckAccessGlobalProxy(reg, scratch, miss);
}
return reg;
}
void MacroAssembler::CheckAccessGlobalProxy(Register holder_reg,
Register scratch,
Label* miss) {
Label same_contexts;
ASSERT(!holder_reg.is(scratch));
ASSERT(!holder_reg.is(ip));
ASSERT(!scratch.is(ip));
// Load current lexical context from the stack frame.
ldr(scratch, MemOperand(fp, StandardFrameConstants::kContextOffset));
// In debug mode, make sure the lexical context is set.
#ifdef DEBUG
cmp(scratch, Operand(0));
Check(ne, "we should not have an empty lexical context");
#endif
// Load the global context of the current context.
int offset = Context::kHeaderSize + Context::GLOBAL_INDEX * kPointerSize;
ldr(scratch, FieldMemOperand(scratch, offset));
ldr(scratch, FieldMemOperand(scratch, GlobalObject::kGlobalContextOffset));
// Check the context is a global context.
if (FLAG_debug_code) {
// TODO(119): avoid push(holder_reg)/pop(holder_reg)
// Cannot use ip as a temporary in this verification code. Due to the fact
// that ip is clobbered as part of cmp with an object Operand.
push(holder_reg); // Temporarily save holder on the stack.
// Read the first word and compare to the global_context_map.
ldr(holder_reg, FieldMemOperand(scratch, HeapObject::kMapOffset));
LoadRoot(ip, Heap::kGlobalContextMapRootIndex);
cmp(holder_reg, ip);
Check(eq, "JSGlobalObject::global_context should be a global context.");
pop(holder_reg); // Restore holder.
}
// Check if both contexts are the same.
ldr(ip, FieldMemOperand(holder_reg, JSGlobalProxy::kContextOffset));
cmp(scratch, Operand(ip));
b(eq, &same_contexts);
// Check the context is a global context.
if (FLAG_debug_code) {
// TODO(119): avoid push(holder_reg)/pop(holder_reg)
// Cannot use ip as a temporary in this verification code. Due to the fact
// that ip is clobbered as part of cmp with an object Operand.
push(holder_reg); // Temporarily save holder on the stack.
mov(holder_reg, ip); // Move ip to its holding place.
LoadRoot(ip, Heap::kNullValueRootIndex);
cmp(holder_reg, ip);
Check(ne, "JSGlobalProxy::context() should not be null.");
ldr(holder_reg, FieldMemOperand(holder_reg, HeapObject::kMapOffset));
LoadRoot(ip, Heap::kGlobalContextMapRootIndex);
cmp(holder_reg, ip);
Check(eq, "JSGlobalObject::global_context should be a global context.");
// Restore ip is not needed. ip is reloaded below.
pop(holder_reg); // Restore holder.
// Restore ip to holder's context.
ldr(ip, FieldMemOperand(holder_reg, JSGlobalProxy::kContextOffset));
}
// Check that the security token in the calling global object is
// compatible with the security token in the receiving global
// object.
int token_offset = Context::kHeaderSize +
Context::SECURITY_TOKEN_INDEX * kPointerSize;
ldr(scratch, FieldMemOperand(scratch, token_offset));
ldr(ip, FieldMemOperand(ip, token_offset));
cmp(scratch, Operand(ip));
b(ne, miss);
bind(&same_contexts);
}
void MacroAssembler::AllocateInNewSpace(int object_size,
Register result,
Register scratch1,
Register scratch2,
Label* gc_required,
AllocationFlags flags) {
ASSERT(!result.is(scratch1));
ASSERT(!scratch1.is(scratch2));
// Load address of new object into result and allocation top address into
// scratch1.
ExternalReference new_space_allocation_top =
ExternalReference::new_space_allocation_top_address();
mov(scratch1, Operand(new_space_allocation_top));
if ((flags & RESULT_CONTAINS_TOP) == 0) {
ldr(result, MemOperand(scratch1));
} else if (FLAG_debug_code) {
// Assert that result actually contains top on entry. scratch2 is used
// immediately below so this use of scratch2 does not cause difference with
// respect to register content between debug and release mode.
ldr(scratch2, MemOperand(scratch1));
cmp(result, scratch2);
Check(eq, "Unexpected allocation top");
}
// Calculate new top and bail out if new space is exhausted. Use result
// to calculate the new top.
ExternalReference new_space_allocation_limit =
ExternalReference::new_space_allocation_limit_address();
mov(scratch2, Operand(new_space_allocation_limit));
ldr(scratch2, MemOperand(scratch2));
add(result, result, Operand(object_size * kPointerSize));
cmp(result, Operand(scratch2));
b(hi, gc_required);
// Update allocation top. result temporarily holds the new top.
if (FLAG_debug_code) {
tst(result, Operand(kObjectAlignmentMask));
Check(eq, "Unaligned allocation in new space");
}
str(result, MemOperand(scratch1));
// Tag and adjust back to start of new object.
if ((flags & TAG_OBJECT) != 0) {
sub(result, result, Operand((object_size * kPointerSize) -
kHeapObjectTag));
} else {
sub(result, result, Operand(object_size * kPointerSize));
}
}
void MacroAssembler::AllocateInNewSpace(Register object_size,
Register result,
Register scratch1,
Register scratch2,
Label* gc_required,
AllocationFlags flags) {
ASSERT(!result.is(scratch1));
ASSERT(!scratch1.is(scratch2));
// Load address of new object into result and allocation top address into
// scratch1.
ExternalReference new_space_allocation_top =
ExternalReference::new_space_allocation_top_address();
mov(scratch1, Operand(new_space_allocation_top));
if ((flags & RESULT_CONTAINS_TOP) == 0) {
ldr(result, MemOperand(scratch1));
} else if (FLAG_debug_code) {
// Assert that result actually contains top on entry. scratch2 is used
// immediately below so this use of scratch2 does not cause difference with
// respect to register content between debug and release mode.
ldr(scratch2, MemOperand(scratch1));
cmp(result, scratch2);
Check(eq, "Unexpected allocation top");
}
// Calculate new top and bail out if new space is exhausted. Use result
// to calculate the new top. Object size is in words so a shift is required to
// get the number of bytes
ExternalReference new_space_allocation_limit =
ExternalReference::new_space_allocation_limit_address();
mov(scratch2, Operand(new_space_allocation_limit));
ldr(scratch2, MemOperand(scratch2));
add(result, result, Operand(object_size, LSL, kPointerSizeLog2));
cmp(result, Operand(scratch2));
b(hi, gc_required);
// Update allocation top. result temporarily holds the new top.
if (FLAG_debug_code) {
tst(result, Operand(kObjectAlignmentMask));
Check(eq, "Unaligned allocation in new space");
}
str(result, MemOperand(scratch1));
// Adjust back to start of new object.
sub(result, result, Operand(object_size, LSL, kPointerSizeLog2));
// Tag object if requested.
if ((flags & TAG_OBJECT) != 0) {
add(result, result, Operand(kHeapObjectTag));
}
}
void MacroAssembler::UndoAllocationInNewSpace(Register object,
Register scratch) {
ExternalReference new_space_allocation_top =
ExternalReference::new_space_allocation_top_address();
// Make sure the object has no tag before resetting top.
and_(object, object, Operand(~kHeapObjectTagMask));
#ifdef DEBUG
// Check that the object un-allocated is below the current top.
mov(scratch, Operand(new_space_allocation_top));
ldr(scratch, MemOperand(scratch));
cmp(object, scratch);
Check(lt, "Undo allocation of non allocated memory");
#endif
// Write the address of the object to un-allocate as the current top.
mov(scratch, Operand(new_space_allocation_top));
str(object, MemOperand(scratch));
}
void MacroAssembler::AllocateTwoByteString(Register result,
Register length,
Register scratch1,
Register scratch2,
Register scratch3,
Label* gc_required) {
// Calculate the number of bytes needed for the characters in the string while
// observing object alignment.
ASSERT((SeqTwoByteString::kHeaderSize & kObjectAlignmentMask) == 0);
mov(scratch1, Operand(length, LSL, 1)); // Length in bytes, not chars.
add(scratch1, scratch1,
Operand(kObjectAlignmentMask + SeqTwoByteString::kHeaderSize));
// AllocateInNewSpace expects the size in words, so we can round down
// to kObjectAlignment and divide by kPointerSize in the same shift.
ASSERT_EQ(kPointerSize, kObjectAlignmentMask + 1);
mov(scratch1, Operand(scratch1, ASR, kPointerSizeLog2));
// Allocate two-byte string in new space.
AllocateInNewSpace(scratch1,
result,
scratch2,
scratch3,
gc_required,
TAG_OBJECT);
// Set the map, length and hash field.
LoadRoot(scratch1, Heap::kStringMapRootIndex);
str(length, FieldMemOperand(result, String::kLengthOffset));
str(scratch1, FieldMemOperand(result, HeapObject::kMapOffset));
mov(scratch2, Operand(String::kEmptyHashField));
str(scratch2, FieldMemOperand(result, String::kHashFieldOffset));
}
void MacroAssembler::AllocateAsciiString(Register result,
Register length,
Register scratch1,
Register scratch2,
Register scratch3,
Label* gc_required) {
// Calculate the number of bytes needed for the characters in the string while
// observing object alignment.
ASSERT((SeqAsciiString::kHeaderSize & kObjectAlignmentMask) == 0);
ASSERT(kCharSize == 1);
add(scratch1, length,
Operand(kObjectAlignmentMask + SeqAsciiString::kHeaderSize));
// AllocateInNewSpace expects the size in words, so we can round down
// to kObjectAlignment and divide by kPointerSize in the same shift.
ASSERT_EQ(kPointerSize, kObjectAlignmentMask + 1);
mov(scratch1, Operand(scratch1, ASR, kPointerSizeLog2));
// Allocate ASCII string in new space.
AllocateInNewSpace(scratch1,
result,
scratch2,
scratch3,
gc_required,
TAG_OBJECT);
// Set the map, length and hash field.
LoadRoot(scratch1, Heap::kAsciiStringMapRootIndex);
mov(scratch1, Operand(Factory::ascii_string_map()));
str(length, FieldMemOperand(result, String::kLengthOffset));
str(scratch1, FieldMemOperand(result, HeapObject::kMapOffset));
mov(scratch2, Operand(String::kEmptyHashField));
str(scratch2, FieldMemOperand(result, String::kHashFieldOffset));
}
void MacroAssembler::AllocateTwoByteConsString(Register result,
Register length,
Register scratch1,
Register scratch2,
Label* gc_required) {
AllocateInNewSpace(ConsString::kSize / kPointerSize,
result,
scratch1,
scratch2,
gc_required,
TAG_OBJECT);
LoadRoot(scratch1, Heap::kConsStringMapRootIndex);
mov(scratch2, Operand(String::kEmptyHashField));
str(length, FieldMemOperand(result, String::kLengthOffset));
str(scratch1, FieldMemOperand(result, HeapObject::kMapOffset));
str(scratch2, FieldMemOperand(result, String::kHashFieldOffset));
}
void MacroAssembler::AllocateAsciiConsString(Register result,
Register length,
Register scratch1,
Register scratch2,
Label* gc_required) {
AllocateInNewSpace(ConsString::kSize / kPointerSize,
result,
scratch1,
scratch2,
gc_required,
TAG_OBJECT);
LoadRoot(scratch1, Heap::kConsAsciiStringMapRootIndex);
mov(scratch2, Operand(String::kEmptyHashField));
str(length, FieldMemOperand(result, String::kLengthOffset));
str(scratch1, FieldMemOperand(result, HeapObject::kMapOffset));
str(scratch2, FieldMemOperand(result, String::kHashFieldOffset));
}
void MacroAssembler::CompareObjectType(Register function,
Register map,
Register type_reg,
InstanceType type) {
ldr(map, FieldMemOperand(function, HeapObject::kMapOffset));
CompareInstanceType(map, type_reg, type);
}
void MacroAssembler::CompareInstanceType(Register map,
Register type_reg,
InstanceType type) {
ldrb(type_reg, FieldMemOperand(map, Map::kInstanceTypeOffset));
cmp(type_reg, Operand(type));
}
void MacroAssembler::CheckMap(Register obj,
Register scratch,
Handle<Map> map,
Label* fail,
bool is_heap_object) {
if (!is_heap_object) {
BranchOnSmi(obj, fail);
}
ldr(scratch, FieldMemOperand(obj, HeapObject::kMapOffset));
mov(ip, Operand(map));
cmp(scratch, ip);
b(ne, fail);
}
void MacroAssembler::TryGetFunctionPrototype(Register function,
Register result,
Register scratch,
Label* miss) {
// Check that the receiver isn't a smi.
BranchOnSmi(function, miss);
// Check that the function really is a function. Load map into result reg.
CompareObjectType(function, result, scratch, JS_FUNCTION_TYPE);
b(ne, miss);
// Make sure that the function has an instance prototype.
Label non_instance;
ldrb(scratch, FieldMemOperand(result, Map::kBitFieldOffset));
tst(scratch, Operand(1 << Map::kHasNonInstancePrototype));
b(ne, &non_instance);
// Get the prototype or initial map from the function.
ldr(result,
FieldMemOperand(function, JSFunction::kPrototypeOrInitialMapOffset));
// If the prototype or initial map is the hole, don't return it and
// simply miss the cache instead. This will allow us to allocate a
// prototype object on-demand in the runtime system.
LoadRoot(ip, Heap::kTheHoleValueRootIndex);
cmp(result, ip);
b(eq, miss);
// If the function does not have an initial map, we're done.
Label done;
CompareObjectType(result, scratch, scratch, MAP_TYPE);
b(ne, &done);
// Get the prototype from the initial map.
ldr(result, FieldMemOperand(result, Map::kPrototypeOffset));
jmp(&done);
// Non-instance prototype: Fetch prototype from constructor field
// in initial map.
bind(&non_instance);
ldr(result, FieldMemOperand(result, Map::kConstructorOffset));
// All done.
bind(&done);
}
void MacroAssembler::CallStub(CodeStub* stub, Condition cond) {
ASSERT(allow_stub_calls()); // stub calls are not allowed in some stubs
Call(stub->GetCode(), RelocInfo::CODE_TARGET, cond);
}
void MacroAssembler::TailCallStub(CodeStub* stub, Condition cond) {
ASSERT(allow_stub_calls()); // stub calls are not allowed in some stubs
Jump(stub->GetCode(), RelocInfo::CODE_TARGET, cond);
}
void MacroAssembler::StubReturn(int argc) {
ASSERT(argc >= 1 && generating_stub());
if (argc > 1) {
add(sp, sp, Operand((argc - 1) * kPointerSize));
}
Ret();
}
void MacroAssembler::IllegalOperation(int num_arguments) {
if (num_arguments > 0) {
add(sp, sp, Operand(num_arguments * kPointerSize));
}
LoadRoot(r0, Heap::kUndefinedValueRootIndex);
}
void MacroAssembler::IntegerToDoubleConversionWithVFP3(Register inReg,
Register outHighReg,
Register outLowReg) {
// ARMv7 VFP3 instructions to implement integer to double conversion.
mov(r7, Operand(inReg, ASR, kSmiTagSize));
vmov(s15, r7);
vcvt(d7, s15);
vmov(outLowReg, outHighReg, d7);
}
void MacroAssembler::GetLeastBitsFromSmi(Register dst,
Register src,
int num_least_bits) {
if (CpuFeatures::IsSupported(ARMv7)) {
ubfx(dst, src, Operand(kSmiTagSize), Operand(num_least_bits - 1));
} else {
mov(dst, Operand(src, ASR, kSmiTagSize));
and_(dst, dst, Operand((1 << num_least_bits) - 1));
}
}
void MacroAssembler::CallRuntime(Runtime::Function* f, int num_arguments) {
// All parameters are on the stack. r0 has the return value after call.
// If the expected number of arguments of the runtime function is
// constant, we check that the actual number of arguments match the
// expectation.
if (f->nargs >= 0 && f->nargs != num_arguments) {
IllegalOperation(num_arguments);
return;
}
// TODO(1236192): Most runtime routines don't need the number of
// arguments passed in because it is constant. At some point we
// should remove this need and make the runtime routine entry code
// smarter.
mov(r0, Operand(num_arguments));
mov(r1, Operand(ExternalReference(f)));
CEntryStub stub(1);
CallStub(&stub);
}
void MacroAssembler::CallRuntime(Runtime::FunctionId fid, int num_arguments) {
CallRuntime(Runtime::FunctionForId(fid), num_arguments);
}
void MacroAssembler::CallExternalReference(const ExternalReference& ext,
int num_arguments) {
mov(r0, Operand(num_arguments));
mov(r1, Operand(ext));
CEntryStub stub(1);
CallStub(&stub);
}
void MacroAssembler::TailCallRuntime(const ExternalReference& ext,
int num_arguments,
int result_size) {
// TODO(1236192): Most runtime routines don't need the number of
// arguments passed in because it is constant. At some point we
// should remove this need and make the runtime routine entry code
// smarter.
mov(r0, Operand(num_arguments));
JumpToRuntime(ext);
}
void MacroAssembler::JumpToRuntime(const ExternalReference& builtin) {
#if defined(__thumb__)
// Thumb mode builtin.
ASSERT((reinterpret_cast<intptr_t>(builtin.address()) & 1) == 1);
#endif
mov(r1, Operand(builtin));
CEntryStub stub(1);
Jump(stub.GetCode(), RelocInfo::CODE_TARGET);
}
void MacroAssembler::InvokeBuiltin(Builtins::JavaScript id,
InvokeJSFlags flags) {
GetBuiltinEntry(r2, id);
if (flags == CALL_JS) {
Call(r2);
} else {
ASSERT(flags == JUMP_JS);
Jump(r2);
}
}
void MacroAssembler::GetBuiltinEntry(Register target, Builtins::JavaScript id) {
// Load the JavaScript builtin function from the builtins object.
ldr(r1, MemOperand(cp, Context::SlotOffset(Context::GLOBAL_INDEX)));
ldr(r1, FieldMemOperand(r1, GlobalObject::kBuiltinsOffset));
int builtins_offset =
JSBuiltinsObject::kJSBuiltinsOffset + (id * kPointerSize);
ldr(r1, FieldMemOperand(r1, builtins_offset));
// Load the code entry point from the function into the target register.
ldr(target, FieldMemOperand(r1, JSFunction::kSharedFunctionInfoOffset));
ldr(target, FieldMemOperand(target, SharedFunctionInfo::kCodeOffset));
add(target, target, Operand(Code::kHeaderSize - kHeapObjectTag));
}
void MacroAssembler::SetCounter(StatsCounter* counter, int value,
Register scratch1, Register scratch2) {
if (FLAG_native_code_counters && counter->Enabled()) {
mov(scratch1, Operand(value));
mov(scratch2, Operand(ExternalReference(counter)));
str(scratch1, MemOperand(scratch2));
}
}
void MacroAssembler::IncrementCounter(StatsCounter* counter, int value,
Register scratch1, Register scratch2) {
ASSERT(value > 0);
if (FLAG_native_code_counters && counter->Enabled()) {
mov(scratch2, Operand(ExternalReference(counter)));
ldr(scratch1, MemOperand(scratch2));
add(scratch1, scratch1, Operand(value));
str(scratch1, MemOperand(scratch2));
}
}
void MacroAssembler::DecrementCounter(StatsCounter* counter, int value,
Register scratch1, Register scratch2) {
ASSERT(value > 0);
if (FLAG_native_code_counters && counter->Enabled()) {
mov(scratch2, Operand(ExternalReference(counter)));
ldr(scratch1, MemOperand(scratch2));
sub(scratch1, scratch1, Operand(value));
str(scratch1, MemOperand(scratch2));
}
}
void MacroAssembler::Assert(Condition cc, const char* msg) {
if (FLAG_debug_code)
Check(cc, msg);
}
void MacroAssembler::Check(Condition cc, const char* msg) {
Label L;
b(cc, &L);
Abort(msg);
// will not return here
bind(&L);
}
void MacroAssembler::Abort(const char* msg) {
// We want to pass the msg string like a smi to avoid GC
// problems, however msg is not guaranteed to be aligned
// properly. Instead, we pass an aligned pointer that is
// a proper v8 smi, but also pass the alignment difference
// from the real pointer as a smi.
intptr_t p1 = reinterpret_cast<intptr_t>(msg);
intptr_t p0 = (p1 & ~kSmiTagMask) + kSmiTag;
ASSERT(reinterpret_cast<Object*>(p0)->IsSmi());
#ifdef DEBUG
if (msg != NULL) {
RecordComment("Abort message: ");
RecordComment(msg);
}
#endif
// Disable stub call restrictions to always allow calls to abort.
set_allow_stub_calls(true);
mov(r0, Operand(p0));
push(r0);
mov(r0, Operand(Smi::FromInt(p1 - p0)));
push(r0);
CallRuntime(Runtime::kAbort, 2);
// will not return here
}
void MacroAssembler::LoadContext(Register dst, int context_chain_length) {
if (context_chain_length > 0) {
// Move up the chain of contexts to the context containing the slot.
ldr(dst, MemOperand(cp, Context::SlotOffset(Context::CLOSURE_INDEX)));
// Load the function context (which is the incoming, outer context).
ldr(dst, FieldMemOperand(dst, JSFunction::kContextOffset));
for (int i = 1; i < context_chain_length; i++) {
ldr(dst, MemOperand(dst, Context::SlotOffset(Context::CLOSURE_INDEX)));
ldr(dst, FieldMemOperand(dst, JSFunction::kContextOffset));
}
// The context may be an intermediate context, not a function context.
ldr(dst, MemOperand(dst, Context::SlotOffset(Context::FCONTEXT_INDEX)));
} else { // Slot is in the current function context.
// The context may be an intermediate context, not a function context.
ldr(dst, MemOperand(cp, Context::SlotOffset(Context::FCONTEXT_INDEX)));
}
}
void MacroAssembler::JumpIfNotBothSmi(Register reg1,
Register reg2,
Label* on_not_both_smi) {
ASSERT_EQ(0, kSmiTag);
tst(reg1, Operand(kSmiTagMask));
tst(reg2, Operand(kSmiTagMask), eq);
b(ne, on_not_both_smi);
}
void MacroAssembler::JumpIfEitherSmi(Register reg1,
Register reg2,
Label* on_either_smi) {
ASSERT_EQ(0, kSmiTag);
tst(reg1, Operand(kSmiTagMask));
tst(reg2, Operand(kSmiTagMask), ne);
b(eq, on_either_smi);
}
void MacroAssembler::JumpIfNonSmisNotBothSequentialAsciiStrings(
Register first,
Register second,
Register scratch1,
Register scratch2,
Label* failure) {
// Test that both first and second are sequential ASCII strings.
// Assume that they are non-smis.
ldr(scratch1, FieldMemOperand(first, HeapObject::kMapOffset));
ldr(scratch2, FieldMemOperand(second, HeapObject::kMapOffset));
ldrb(scratch1, FieldMemOperand(scratch1, Map::kInstanceTypeOffset));
ldrb(scratch2, FieldMemOperand(scratch2, Map::kInstanceTypeOffset));
int kFlatAsciiStringMask =
kIsNotStringMask | kStringEncodingMask | kStringRepresentationMask;
int kFlatAsciiStringTag = ASCII_STRING_TYPE;
and_(scratch1, scratch1, Operand(kFlatAsciiStringMask));
and_(scratch2, scratch2, Operand(kFlatAsciiStringMask));
cmp(scratch1, Operand(kFlatAsciiStringTag));
// Ignore second test if first test failed.
cmp(scratch2, Operand(kFlatAsciiStringTag), eq);
b(ne, failure);
}
void MacroAssembler::JumpIfNotBothSequentialAsciiStrings(Register first,
Register second,
Register scratch1,
Register scratch2,
Label* failure) {
// Check that neither is a smi.
ASSERT_EQ(0, kSmiTag);
and_(scratch1, first, Operand(second));
tst(scratch1, Operand(kSmiTagMask));
b(eq, failure);
JumpIfNonSmisNotBothSequentialAsciiStrings(first,
second,
scratch1,
scratch2,
failure);
}
#ifdef ENABLE_DEBUGGER_SUPPORT
CodePatcher::CodePatcher(byte* address, int instructions)
: address_(address),
instructions_(instructions),
size_(instructions * Assembler::kInstrSize),
masm_(address, size_ + Assembler::kGap) {
// Create a new macro assembler pointing to the address of the code to patch.
// The size is adjusted with kGap on order for the assembler to generate size
// bytes of instructions without failing with buffer size constraints.
ASSERT(masm_.reloc_info_writer.pos() == address_ + size_ + Assembler::kGap);
}
CodePatcher::~CodePatcher() {
// Indicate that code has changed.
CPU::FlushICache(address_, size_);
// Check that the code was patched as expected.
ASSERT(masm_.pc_ == address_ + size_);
ASSERT(masm_.reloc_info_writer.pos() == address_ + size_ + Assembler::kGap);
}
void CodePatcher::Emit(Instr x) {
masm()->emit(x);
}
void CodePatcher::Emit(Address addr) {
masm()->emit(reinterpret_cast<Instr>(addr));
}
#endif // ENABLE_DEBUGGER_SUPPORT
} } // namespace v8::internal