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v8/src/ia32/macro-assembler-ia32.cc
ager@chromium.org ef85ba46b0 First round of size reduction for JumpTargets. Reduce their size by 
two words: there is no reason to keep a pointer to the current code
generator and macro assembler in the JumpTarget.
Review URL: http://codereview.chromium.org/113458

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@1987 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
2009-05-18 12:26:59 +00:00

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// Copyright 2006-2008 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"
#include "serialize.h"
namespace v8 { namespace internal {
// -------------------------------------------------------------------------
// MacroAssembler implementation.
MacroAssembler::MacroAssembler(void* buffer, int size)
: Assembler(buffer, size),
unresolved_(0),
generating_stub_(false),
allow_stub_calls_(true),
code_object_(Heap::undefined_value()) {
}
static void RecordWriteHelper(MacroAssembler* masm,
Register object,
Register addr,
Register scratch) {
Label fast;
// Compute the page address from the heap object pointer, leave it
// in 'object'.
masm->and_(object, ~Page::kPageAlignmentMask);
// Compute the bit addr in the remembered set, leave it in "addr".
masm->sub(addr, Operand(object));
masm->shr(addr, kObjectAlignmentBits);
// If the bit offset lies beyond the normal remembered set range, it is in
// the extra remembered set area of a large object.
masm->cmp(addr, Page::kPageSize / kPointerSize);
masm->j(less, &fast);
// Adjust 'addr' to be relative to the start of the extra remembered set
// and the page address in 'object' to be the address of the extra
// remembered set.
masm->sub(Operand(addr), Immediate(Page::kPageSize / kPointerSize));
// Load the array length into 'scratch' and multiply by four to get the
// size in bytes of the elements.
masm->mov(scratch, Operand(object, Page::kObjectStartOffset
+ FixedArray::kLengthOffset));
masm->shl(scratch, kObjectAlignmentBits);
// Add the page header, array header, and array body size to the page
// address.
masm->add(Operand(object), Immediate(Page::kObjectStartOffset
+ Array::kHeaderSize));
masm->add(object, Operand(scratch));
// NOTE: For now, we use the bit-test-and-set (bts) x86 instruction
// to limit code size. We should probably evaluate this decision by
// measuring the performance of an equivalent implementation using
// "simpler" instructions
masm->bind(&fast);
masm->bts(Operand(object, 0), addr);
}
class RecordWriteStub : public CodeStub {
public:
RecordWriteStub(Register object, Register addr, Register scratch)
: object_(object), addr_(addr), scratch_(scratch) { }
void Generate(MacroAssembler* masm);
private:
Register object_;
Register addr_;
Register scratch_;
#ifdef DEBUG
void Print() {
PrintF("RecordWriteStub (object reg %d), (addr reg %d), (scratch reg %d)\n",
object_.code(), addr_.code(), scratch_.code());
}
#endif
// Minor key encoding in 12 bits of three registers (object, address and
// scratch) OOOOAAAASSSS.
class ScratchBits: public BitField<uint32_t, 0, 4> {};
class AddressBits: public BitField<uint32_t, 4, 4> {};
class ObjectBits: public BitField<uint32_t, 8, 4> {};
Major MajorKey() { return RecordWrite; }
int MinorKey() {
// Encode the registers.
return ObjectBits::encode(object_.code()) |
AddressBits::encode(addr_.code()) |
ScratchBits::encode(scratch_.code());
}
};
void RecordWriteStub::Generate(MacroAssembler* masm) {
RecordWriteHelper(masm, object_, addr_, scratch_);
masm->ret(0);
}
// Set the remembered set bit for [object+offset].
// object is the object being stored into, value is the object being stored.
// If offset is zero, then the scratch register contains the array index into
// the elements array represented as a Smi.
// All registers are clobbered by the operation.
void MacroAssembler::RecordWrite(Register object, int offset,
Register value, Register scratch) {
// First, check if a remembered set write is even needed. The tests below
// catch stores of Smis and stores into young gen (which does not have space
// for the remembered set bits.
Label done;
// This optimization cannot survive serialization and deserialization,
// so we disable as long as serialization can take place.
int32_t new_space_start =
reinterpret_cast<int32_t>(ExternalReference::new_space_start().address());
if (Serializer::enabled() || new_space_start < 0) {
// Cannot do smart bit-twiddling. Need to do two consecutive checks.
// Check for Smi first.
test(value, Immediate(kSmiTagMask));
j(zero, &done);
// Test that the object address is not in the new space. We cannot
// set remembered set bits in the new space.
mov(value, Operand(object));
and_(value, Heap::NewSpaceMask());
cmp(Operand(value), Immediate(ExternalReference::new_space_start()));
j(equal, &done);
} else {
// move the value SmiTag into the sign bit
shl(value, 31);
// combine the object with value SmiTag
or_(value, Operand(object));
// remove the uninteresing bits inside the page
and_(value, Heap::NewSpaceMask() | (1 << 31));
// xor has two effects:
// - if the value was a smi, then the result will be negative
// - if the object is pointing into new space area the page bits will
// all be zero
xor_(value, new_space_start | (1 << 31));
// Check for both conditions in one branch
j(less_equal, &done);
}
if ((offset > 0) && (offset < Page::kMaxHeapObjectSize)) {
// Compute the bit offset in the remembered set, leave it in 'value'.
mov(value, Operand(object));
and_(value, Page::kPageAlignmentMask);
add(Operand(value), Immediate(offset));
shr(value, kObjectAlignmentBits);
// Compute the page address from the heap object pointer, leave it in
// 'object'.
and_(object, ~Page::kPageAlignmentMask);
// NOTE: For now, we use the bit-test-and-set (bts) x86 instruction
// to limit code size. We should probably evaluate this decision by
// measuring the performance of an equivalent implementation using
// "simpler" instructions
bts(Operand(object, 0), value);
} else {
Register dst = scratch;
if (offset != 0) {
lea(dst, Operand(object, offset));
} else {
// array access: calculate the destination address in the same manner as
// KeyedStoreIC::GenerateGeneric
lea(dst,
Operand(object, dst, times_2, Array::kHeaderSize - kHeapObjectTag));
}
// If we are already generating a shared stub, not inlining the
// record write code isn't going to save us any memory.
if (generating_stub()) {
RecordWriteHelper(this, object, dst, value);
} else {
RecordWriteStub stub(object, dst, value);
CallStub(&stub);
}
}
bind(&done);
}
#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 };
ExternalReference reg_addr =
ExternalReference(Debug_Address::Register(i));
mov(Operand::StaticVariable(reg_addr), reg);
}
}
}
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 };
ExternalReference reg_addr =
ExternalReference(Debug_Address::Register(i));
mov(reg, Operand::StaticVariable(reg_addr));
}
}
}
void MacroAssembler::PushRegistersFromMemory(RegList regs) {
ASSERT((regs & ~kJSCallerSaved) == 0);
// Push the content of the memory location to the stack.
for (int i = 0; i < kNumJSCallerSaved; i++) {
int r = JSCallerSavedCode(i);
if ((regs & (1 << r)) != 0) {
ExternalReference reg_addr =
ExternalReference(Debug_Address::Register(i));
push(Operand::StaticVariable(reg_addr));
}
}
}
void MacroAssembler::PopRegistersToMemory(RegList regs) {
ASSERT((regs & ~kJSCallerSaved) == 0);
// Pop the content from the stack to the memory location.
for (int i = kNumJSCallerSaved; --i >= 0;) {
int r = JSCallerSavedCode(i);
if ((regs & (1 << r)) != 0) {
ExternalReference reg_addr =
ExternalReference(Debug_Address::Register(i));
pop(Operand::StaticVariable(reg_addr));
}
}
}
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 = kNumJSCallerSaved; --i >= 0;) {
int r = JSCallerSavedCode(i);
if ((regs & (1 << r)) != 0) {
mov(scratch, Operand(base, 0));
ExternalReference reg_addr =
ExternalReference(Debug_Address::Register(i));
mov(Operand::StaticVariable(reg_addr), scratch);
lea(base, Operand(base, kPointerSize));
}
}
}
#endif
void MacroAssembler::Set(Register dst, const Immediate& x) {
if (x.is_zero()) {
xor_(dst, Operand(dst)); // shorter than mov
} else {
mov(dst, x);
}
}
void MacroAssembler::Set(const Operand& dst, const Immediate& x) {
mov(dst, x);
}
void MacroAssembler::CmpObjectType(Register heap_object,
InstanceType type,
Register map) {
mov(map, FieldOperand(heap_object, HeapObject::kMapOffset));
CmpInstanceType(map, type);
}
void MacroAssembler::CmpInstanceType(Register map, InstanceType type) {
cmpb(FieldOperand(map, Map::kInstanceTypeOffset),
static_cast<int8_t>(type));
}
void MacroAssembler::FCmp() {
fcompp();
push(eax);
fnstsw_ax();
sahf();
pop(eax);
}
void MacroAssembler::EnterFrame(StackFrame::Type type) {
push(ebp);
mov(ebp, Operand(esp));
push(esi);
push(Immediate(Smi::FromInt(type)));
push(Immediate(CodeObject()));
if (FLAG_debug_code) {
cmp(Operand(esp, 0), Immediate(Factory::undefined_value()));
Check(not_equal, "code object not properly patched");
}
}
void MacroAssembler::LeaveFrame(StackFrame::Type type) {
if (FLAG_debug_code) {
cmp(Operand(ebp, StandardFrameConstants::kMarkerOffset),
Immediate(Smi::FromInt(type)));
Check(equal, "stack frame types must match");
}
leave();
}
void MacroAssembler::EnterExitFrame(StackFrame::Type type) {
ASSERT(type == StackFrame::EXIT || type == StackFrame::EXIT_DEBUG);
// Setup the frame structure on the stack.
ASSERT(ExitFrameConstants::kPPDisplacement == +2 * kPointerSize);
ASSERT(ExitFrameConstants::kCallerPCOffset == +1 * kPointerSize);
ASSERT(ExitFrameConstants::kCallerFPOffset == 0 * kPointerSize);
push(ebp);
mov(ebp, Operand(esp));
// Reserve room for entry stack pointer and push the debug marker.
ASSERT(ExitFrameConstants::kSPOffset == -1 * kPointerSize);
push(Immediate(0)); // saved entry sp, patched before call
push(Immediate(type == StackFrame::EXIT_DEBUG ? 1 : 0));
// Save the frame pointer and the context in top.
ExternalReference c_entry_fp_address(Top::k_c_entry_fp_address);
ExternalReference context_address(Top::k_context_address);
mov(Operand::StaticVariable(c_entry_fp_address), ebp);
mov(Operand::StaticVariable(context_address), esi);
// Setup argc and argv in callee-saved registers.
int offset = StandardFrameConstants::kCallerSPOffset - kPointerSize;
mov(edi, Operand(eax));
lea(esi, Operand(ebp, eax, times_4, offset));
#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 (type == StackFrame::EXIT_DEBUG) {
// TODO(1243899): This should be symmetric to
// CopyRegistersFromStackToMemory() but it isn't! esp is assumed
// correct here, but computed for the other call. Very error
// prone! FIX THIS. Actually there are deeper problems with
// register saving than this asymmetry (see the bug report
// associated with this issue).
PushRegistersFromMemory(kJSCallerSaved);
}
#endif
// Reserve space for two arguments: argc and argv.
sub(Operand(esp), Immediate(2 * kPointerSize));
// Get the required frame alignment for the OS.
static const int kFrameAlignment = OS::ActivationFrameAlignment();
if (kFrameAlignment > 0) {
ASSERT(IsPowerOf2(kFrameAlignment));
and_(esp, -kFrameAlignment);
}
// Patch the saved entry sp.
mov(Operand(ebp, ExitFrameConstants::kSPOffset), esp);
}
void MacroAssembler::LeaveExitFrame(StackFrame::Type type) {
#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 (type == StackFrame::EXIT_DEBUG) {
// It's okay to clobber register ebx below because we don't need
// the function pointer after this.
const int kCallerSavedSize = kNumJSCallerSaved * kPointerSize;
int kOffset = ExitFrameConstants::kDebugMarkOffset - kCallerSavedSize;
lea(ebx, Operand(ebp, kOffset));
CopyRegistersFromStackToMemory(ebx, ecx, kJSCallerSaved);
}
#endif
// Get the return address from the stack and restore the frame pointer.
mov(ecx, Operand(ebp, 1 * kPointerSize));
mov(ebp, Operand(ebp, 0 * kPointerSize));
// Pop the arguments and the receiver from the caller stack.
lea(esp, Operand(esi, 1 * kPointerSize));
// Restore current context from top and clear it in debug mode.
ExternalReference context_address(Top::k_context_address);
mov(esi, Operand::StaticVariable(context_address));
#ifdef DEBUG
mov(Operand::StaticVariable(context_address), Immediate(0));
#endif
// Push the return address to get ready to return.
push(ecx);
// Clear the top frame.
ExternalReference c_entry_fp_address(Top::k_c_entry_fp_address);
mov(Operand::StaticVariable(c_entry_fp_address), Immediate(0));
}
void MacroAssembler::PushTryHandler(CodeLocation try_location,
HandlerType type) {
ASSERT(StackHandlerConstants::kSize == 6 * kPointerSize); // adjust this code
// The pc (return address) is already on TOS.
if (try_location == IN_JAVASCRIPT) {
if (type == TRY_CATCH_HANDLER) {
push(Immediate(StackHandler::TRY_CATCH));
} else {
push(Immediate(StackHandler::TRY_FINALLY));
}
push(Immediate(Smi::FromInt(StackHandler::kCodeNotPresent)));
push(ebp);
push(edi);
} else {
ASSERT(try_location == IN_JS_ENTRY);
// The parameter pointer is meaningless here and ebp does not
// point to a JS frame. So we save NULL for both pp and ebp. We
// expect the code throwing an exception to check ebp before
// dereferencing it to restore the context.
push(Immediate(StackHandler::ENTRY));
push(Immediate(Smi::FromInt(StackHandler::kCodeNotPresent)));
push(Immediate(0)); // NULL frame pointer
push(Immediate(0)); // NULL parameter pointer
}
// Cached TOS.
mov(eax, Operand::StaticVariable(ExternalReference(Top::k_handler_address)));
// Link this handler.
mov(Operand::StaticVariable(ExternalReference(Top::k_handler_address)), esp);
}
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());
JSObject* prototype = JSObject::cast(object->GetPrototype());
if (Heap::InNewSpace(prototype)) {
// Get the map of the current object.
mov(scratch, FieldOperand(reg, HeapObject::kMapOffset));
cmp(Operand(scratch), Immediate(Handle<Map>(object->map())));
// Branch on the result of the map check.
j(not_equal, miss, not_taken);
// 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.
// We load the prototype from the map in the scratch register.
mov(scratch, FieldOperand(reg, HeapObject::kMapOffset));
}
// The prototype is in new space; we cannot store a reference
// to it in the code. Load it from the map.
reg = holder_reg; // from now the object is in holder_reg
mov(reg, FieldOperand(scratch, Map::kPrototypeOffset));
} else {
// Check the map of the current object.
cmp(FieldOperand(reg, HeapObject::kMapOffset),
Immediate(Handle<Map>(object->map())));
// Branch on the result of the map check.
j(not_equal, miss, not_taken);
// 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);
}
// The prototype is in old space; load it directly.
reg = holder_reg; // from now the object is in holder_reg
mov(reg, Handle<JSObject>(prototype));
}
// Go to the next object in the prototype chain.
object = prototype;
}
// Check the holder map.
cmp(FieldOperand(reg, HeapObject::kMapOffset),
Immediate(Handle<Map>(holder->map())));
j(not_equal, miss, not_taken);
// 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));
// Load current lexical context from the stack frame.
mov(scratch, Operand(ebp, StandardFrameConstants::kContextOffset));
// When generating debug code, make sure the lexical context is set.
if (FLAG_debug_code) {
cmp(Operand(scratch), Immediate(0));
Check(not_equal, "we should not have an empty lexical context");
}
// Load the global context of the current context.
int offset = Context::kHeaderSize + Context::GLOBAL_INDEX * kPointerSize;
mov(scratch, FieldOperand(scratch, offset));
mov(scratch, FieldOperand(scratch, GlobalObject::kGlobalContextOffset));
// Check the context is a global context.
if (FLAG_debug_code) {
push(scratch);
// Read the first word and compare to global_context_map.
mov(scratch, FieldOperand(scratch, HeapObject::kMapOffset));
cmp(scratch, Factory::global_context_map());
Check(equal, "JSGlobalObject::global_context should be a global context.");
pop(scratch);
}
// Check if both contexts are the same.
cmp(scratch, FieldOperand(holder_reg, JSGlobalProxy::kContextOffset));
j(equal, &same_contexts, taken);
// Compare security tokens, save holder_reg on the stack so we can use it
// as a temporary register.
//
// TODO(119): avoid push(holder_reg)/pop(holder_reg)
push(holder_reg);
// Check that the security token in the calling global object is
// compatible with the security token in the receiving global
// object.
mov(holder_reg, FieldOperand(holder_reg, JSGlobalProxy::kContextOffset));
// Check the context is a global context.
if (FLAG_debug_code) {
cmp(holder_reg, Factory::null_value());
Check(not_equal, "JSGlobalProxy::context() should not be null.");
push(holder_reg);
// Read the first word and compare to global_context_map(),
mov(holder_reg, FieldOperand(holder_reg, HeapObject::kMapOffset));
cmp(holder_reg, Factory::global_context_map());
Check(equal, "JSGlobalObject::global_context should be a global context.");
pop(holder_reg);
}
int token_offset = Context::kHeaderSize +
Context::SECURITY_TOKEN_INDEX * kPointerSize;
mov(scratch, FieldOperand(scratch, token_offset));
cmp(scratch, FieldOperand(holder_reg, token_offset));
pop(holder_reg);
j(not_equal, miss, not_taken);
bind(&same_contexts);
}
void MacroAssembler::NegativeZeroTest(CodeGenerator* cgen,
Register result,
Register op,
JumpTarget* then_target) {
JumpTarget ok;
test(result, Operand(result));
ok.Branch(not_zero, taken);
test(op, Operand(op));
then_target->Branch(sign, not_taken);
ok.Bind();
}
void MacroAssembler::NegativeZeroTest(Register result,
Register op,
Label* then_label) {
Label ok;
test(result, Operand(result));
j(not_zero, &ok, taken);
test(op, Operand(op));
j(sign, then_label, not_taken);
bind(&ok);
}
void MacroAssembler::NegativeZeroTest(Register result,
Register op1,
Register op2,
Register scratch,
Label* then_label) {
Label ok;
test(result, Operand(result));
j(not_zero, &ok, taken);
mov(scratch, Operand(op1));
or_(scratch, Operand(op2));
j(sign, then_label, not_taken);
bind(&ok);
}
void MacroAssembler::TryGetFunctionPrototype(Register function,
Register result,
Register scratch,
Label* miss) {
// Check that the receiver isn't a smi.
test(function, Immediate(kSmiTagMask));
j(zero, miss, not_taken);
// Check that the function really is a function.
CmpObjectType(function, JS_FUNCTION_TYPE, result);
j(not_equal, miss, not_taken);
// Make sure that the function has an instance prototype.
Label non_instance;
movzx_b(scratch, FieldOperand(result, Map::kBitFieldOffset));
test(scratch, Immediate(1 << Map::kHasNonInstancePrototype));
j(not_zero, &non_instance, not_taken);
// Get the prototype or initial map from the function.
mov(result,
FieldOperand(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.
cmp(Operand(result), Immediate(Factory::the_hole_value()));
j(equal, miss, not_taken);
// If the function does not have an initial map, we're done.
Label done;
CmpObjectType(result, MAP_TYPE, scratch);
j(not_equal, &done);
// Get the prototype from the initial map.
mov(result, FieldOperand(result, Map::kPrototypeOffset));
jmp(&done);
// Non-instance prototype: Fetch prototype from constructor field
// in initial map.
bind(&non_instance);
mov(result, FieldOperand(result, Map::kConstructorOffset));
// All done.
bind(&done);
}
void MacroAssembler::CallStub(CodeStub* stub) {
ASSERT(allow_stub_calls()); // calls are not allowed in some stubs
call(stub->GetCode(), RelocInfo::CODE_TARGET);
}
void MacroAssembler::StubReturn(int argc) {
ASSERT(argc >= 1 && generating_stub());
ret((argc - 1) * kPointerSize);
}
void MacroAssembler::IllegalOperation(int num_arguments) {
if (num_arguments > 0) {
add(Operand(esp), Immediate(num_arguments * kPointerSize));
}
mov(eax, Immediate(Factory::undefined_value()));
}
void MacroAssembler::CallRuntime(Runtime::FunctionId id, int num_arguments) {
CallRuntime(Runtime::FunctionForId(id), num_arguments);
}
void MacroAssembler::CallRuntime(Runtime::Function* f, int num_arguments) {
// 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;
}
Runtime::FunctionId function_id =
static_cast<Runtime::FunctionId>(f->stub_id);
RuntimeStub stub(function_id, num_arguments);
CallStub(&stub);
}
void MacroAssembler::TailCallRuntime(const ExternalReference& ext,
int num_arguments) {
// 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.
Set(eax, Immediate(num_arguments));
JumpToBuiltin(ext);
}
void MacroAssembler::JumpToBuiltin(const ExternalReference& ext) {
// Set the entry point and jump to the C entry runtime stub.
mov(ebx, Immediate(ext));
CEntryStub ces;
jmp(ces.GetCode(), RelocInfo::CODE_TARGET);
}
void MacroAssembler::InvokePrologue(const ParameterCount& expected,
const ParameterCount& actual,
Handle<Code> code_constant,
const Operand& code_operand,
Label* done,
InvokeFlag flag) {
bool definitely_matches = false;
Label invoke;
if (expected.is_immediate()) {
ASSERT(actual.is_immediate());
if (expected.immediate() == actual.immediate()) {
definitely_matches = true;
} else {
mov(eax, 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(ebx, expected.immediate());
}
}
} else {
if (actual.is_immediate()) {
// Expected is in register, actual is immediate. This is the
// case when we invoke function values without going through the
// IC mechanism.
cmp(expected.reg(), actual.immediate());
j(equal, &invoke);
ASSERT(expected.reg().is(ebx));
mov(eax, actual.immediate());
} else if (!expected.reg().is(actual.reg())) {
// Both expected and actual are in (different) registers. This
// is the case when we invoke functions using call and apply.
cmp(expected.reg(), Operand(actual.reg()));
j(equal, &invoke);
ASSERT(actual.reg().is(eax));
ASSERT(expected.reg().is(ebx));
}
}
if (!definitely_matches) {
Handle<Code> adaptor =
Handle<Code>(Builtins::builtin(Builtins::ArgumentsAdaptorTrampoline));
if (!code_constant.is_null()) {
mov(edx, Immediate(code_constant));
add(Operand(edx), Immediate(Code::kHeaderSize - kHeapObjectTag));
} else if (!code_operand.is_reg(edx)) {
mov(edx, code_operand);
}
if (flag == CALL_FUNCTION) {
call(adaptor, RelocInfo::CODE_TARGET);
jmp(done);
} else {
jmp(adaptor, RelocInfo::CODE_TARGET);
}
bind(&invoke);
}
}
void MacroAssembler::InvokeCode(const Operand& 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);
jmp(code);
}
bind(&done);
}
void MacroAssembler::InvokeCode(Handle<Code> code,
const ParameterCount& expected,
const ParameterCount& actual,
RelocInfo::Mode rmode,
InvokeFlag flag) {
Label done;
Operand dummy(eax);
InvokePrologue(expected, actual, code, dummy, &done, flag);
if (flag == CALL_FUNCTION) {
call(code, rmode);
} else {
ASSERT(flag == JUMP_FUNCTION);
jmp(code, rmode);
}
bind(&done);
}
void MacroAssembler::InvokeFunction(Register fun,
const ParameterCount& actual,
InvokeFlag flag) {
ASSERT(fun.is(edi));
mov(edx, FieldOperand(edi, JSFunction::kSharedFunctionInfoOffset));
mov(esi, FieldOperand(edi, JSFunction::kContextOffset));
mov(ebx, FieldOperand(edx, SharedFunctionInfo::kFormalParameterCountOffset));
mov(edx, FieldOperand(edx, SharedFunctionInfo::kCodeOffset));
lea(edx, FieldOperand(edx, Code::kHeaderSize));
ParameterCount expected(ebx);
InvokeCode(Operand(edx), expected, actual, flag);
}
void MacroAssembler::InvokeBuiltin(Builtins::JavaScript id, InvokeFlag flag) {
bool resolved;
Handle<Code> code = ResolveBuiltin(id, &resolved);
// Calls are not allowed in some stubs.
ASSERT(flag == JUMP_FUNCTION || allow_stub_calls());
// Rely on the assertion to check that the number of provided
// arguments match the expected number of arguments. Fake a
// parameter count to avoid emitting code to do the check.
ParameterCount expected(0);
InvokeCode(Handle<Code>(code), expected, expected,
RelocInfo::CODE_TARGET, flag);
const char* name = Builtins::GetName(id);
int argc = Builtins::GetArgumentsCount(id);
if (!resolved) {
uint32_t flags =
Bootstrapper::FixupFlagsArgumentsCount::encode(argc) |
Bootstrapper::FixupFlagsIsPCRelative::encode(true) |
Bootstrapper::FixupFlagsUseCodeObject::encode(false);
Unresolved entry = { pc_offset() - sizeof(int32_t), flags, name };
unresolved_.Add(entry);
}
}
void MacroAssembler::GetBuiltinEntry(Register target, Builtins::JavaScript id) {
bool resolved;
Handle<Code> code = ResolveBuiltin(id, &resolved);
const char* name = Builtins::GetName(id);
int argc = Builtins::GetArgumentsCount(id);
mov(Operand(target), Immediate(code));
if (!resolved) {
uint32_t flags =
Bootstrapper::FixupFlagsArgumentsCount::encode(argc) |
Bootstrapper::FixupFlagsIsPCRelative::encode(false) |
Bootstrapper::FixupFlagsUseCodeObject::encode(true);
Unresolved entry = { pc_offset() - sizeof(int32_t), flags, name };
unresolved_.Add(entry);
}
add(Operand(target), Immediate(Code::kHeaderSize - kHeapObjectTag));
}
Handle<Code> MacroAssembler::ResolveBuiltin(Builtins::JavaScript id,
bool* resolved) {
// Move the builtin function into the temporary function slot by
// reading it from the builtins object. NOTE: We should be able to
// reduce this to two instructions by putting the function table in
// the global object instead of the "builtins" object and by using a
// real register for the function.
mov(edx, Operand(esi, Context::SlotOffset(Context::GLOBAL_INDEX)));
mov(edx, FieldOperand(edx, GlobalObject::kBuiltinsOffset));
int builtins_offset =
JSBuiltinsObject::kJSBuiltinsOffset + (id * kPointerSize);
mov(edi, FieldOperand(edx, builtins_offset));
return Builtins::GetCode(id, resolved);
}
void MacroAssembler::Ret() {
ret(0);
}
void MacroAssembler::SetCounter(StatsCounter* counter, int value) {
if (FLAG_native_code_counters && counter->Enabled()) {
mov(Operand::StaticVariable(ExternalReference(counter)), Immediate(value));
}
}
void MacroAssembler::IncrementCounter(StatsCounter* counter, int value) {
ASSERT(value > 0);
if (FLAG_native_code_counters && counter->Enabled()) {
Operand operand = Operand::StaticVariable(ExternalReference(counter));
if (value == 1) {
inc(operand);
} else {
add(operand, Immediate(value));
}
}
}
void MacroAssembler::DecrementCounter(StatsCounter* counter, int value) {
ASSERT(value > 0);
if (FLAG_native_code_counters && counter->Enabled()) {
Operand operand = Operand::StaticVariable(ExternalReference(counter));
if (value == 1) {
dec(operand);
} else {
sub(operand, Immediate(value));
}
}
}
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;
j(cc, &L, taken);
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
push(eax);
push(Immediate(p0));
push(Immediate(reinterpret_cast<intptr_t>(Smi::FromInt(p1 - p0))));
CallRuntime(Runtime::kAbort, 2);
// will not return here
}
CodePatcher::CodePatcher(byte* address, int size)
: address_(address), size_(size), 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);
}
} } // namespace v8::internal
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