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638cb4f91d
v8/src/arm/macro-assembler-arm.cc
ager@chromium.org 638cb4f91d Always load the JavaScript builtins code entry from the JavaScript 
function instead of baking in the address of the first one that we see
in code.

This removes the need for fixups processing and makes the stubs safe
when there is no natives cache and therefore multiple versions of the
builtin functions.

Review URL: http://codereview.chromium.org/594009

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@3832 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
2010-02-11 08:05:33 +00:00

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// 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(Heap::NewSpaceMask()));
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, &regular_invoke);
mov(r0, Operand(actual.immediate()));
} else {
cmp(expected.reg(), Operand(actual.reg()));
b(eq, &regular_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(&regular_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);
}
#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::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
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