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ara-mdk / platform / external / v8 / 5913587db4c6bab03d97bfe44b06289fd6d7270d / . / src / arm / macro-assembler-arm.cc
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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 <limits.h> // For LONG_MIN, LONG_MAX.
#include "v8.h"
#if defined(V8_TARGET_ARCH_ARM)
#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 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) {
#if USE_BLX
// On ARMv5 and after the recommended call sequence is:
// ldr ip, [pc, #...]
// blx ip
// The two instructions (ldr and blx) could be separated by a constant
// pool and the code would still work. The issue comes from the
// patching code which expect the ldr to be just above the blx.
{ BlockConstPoolScope block_const_pool(this);
// Statement positions are expected to be recorded when the target
// address is loaded. The mov method will automatically record
// positions when pc is the target, since this is not the case here
// we have to do it explicitly.
WriteRecordedPositions();
mov(ip, Operand(target, rmode), LeaveCC, cond);
blx(ip, cond);
}
ASSERT(kCallTargetAddressOffset == 2 * kInstrSize);
#else
// 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);
ASSERT(kCallTargetAddressOffset == kInstrSize);
#endif
}
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::Swap(Register reg1,
Register reg2,
Register scratch,
Condition cond) {
if (scratch.is(no_reg)) {
eor(reg1, reg1, Operand(reg2), LeaveCC, cond);
eor(reg2, reg2, Operand(reg1), LeaveCC, cond);
eor(reg1, reg1, Operand(reg2), LeaveCC, cond);
} else {
mov(scratch, reg1, LeaveCC, cond);
mov(reg1, reg2, LeaveCC, cond);
mov(reg2, scratch, LeaveCC, cond);
}
}
void MacroAssembler::Call(Label* target) {
bl(target);
}
void MacroAssembler::Move(Register dst, Handle<Object> value) {
mov(dst, Operand(value));
}
void MacroAssembler::Move(Register dst, Register src) {
if (!dst.is(src)) {
mov(dst, src);
}
}
void MacroAssembler::And(Register dst, Register src1, const Operand& src2,
Condition cond) {
if (!CpuFeatures::IsSupported(ARMv7) || src2.is_single_instruction()) {
and_(dst, src1, src2, LeaveCC, cond);
return;
}
int32_t immediate = src2.immediate();
if (immediate == 0) {
mov(dst, Operand(0, RelocInfo::NONE), LeaveCC, cond);
return;
}
if (IsPowerOf2(immediate + 1) && ((immediate & 1) != 0)) {
ubfx(dst, src1, 0, WhichPowerOf2(immediate + 1), cond);
return;
}
and_(dst, src1, src2, LeaveCC, cond);
}
void MacroAssembler::Ubfx(Register dst, Register src1, int lsb, int width,
Condition cond) {
ASSERT(lsb < 32);
if (!CpuFeatures::IsSupported(ARMv7)) {
int mask = (1 << (width + lsb)) - 1 - ((1 << lsb) - 1);
and_(dst, src1, Operand(mask), LeaveCC, cond);
if (lsb != 0) {
mov(dst, Operand(dst, LSR, lsb), LeaveCC, cond);
}
} else {
ubfx(dst, src1, lsb, width, cond);
}
}
void MacroAssembler::Sbfx(Register dst, Register src1, int lsb, int width,
Condition cond) {
ASSERT(lsb < 32);
if (!CpuFeatures::IsSupported(ARMv7)) {
int mask = (1 << (width + lsb)) - 1 - ((1 << lsb) - 1);
and_(dst, src1, Operand(mask), LeaveCC, cond);
int shift_up = 32 - lsb - width;
int shift_down = lsb + shift_up;
if (shift_up != 0) {
mov(dst, Operand(dst, LSL, shift_up), LeaveCC, cond);
}
if (shift_down != 0) {
mov(dst, Operand(dst, ASR, shift_down), LeaveCC, cond);
}
} else {
sbfx(dst, src1, lsb, width, cond);
}
}
void MacroAssembler::Bfc(Register dst, int lsb, int width, Condition cond) {
ASSERT(lsb < 32);
if (!CpuFeatures::IsSupported(ARMv7)) {
int mask = (1 << (width + lsb)) - 1 - ((1 << lsb) - 1);
bic(dst, dst, Operand(mask));
} else {
bfc(dst, lsb, width, cond);
}
}
void MacroAssembler::Usat(Register dst, int satpos, const Operand& src,
Condition cond) {
if (!CpuFeatures::IsSupported(ARMv7)) {
ASSERT(!dst.is(pc) && !src.rm().is(pc));
ASSERT((satpos >= 0) && (satpos <= 31));
// These asserts are required to ensure compatibility with the ARMv7
// implementation.
ASSERT((src.shift_op() == ASR) || (src.shift_op() == LSL));
ASSERT(src.rs().is(no_reg));
Label done;
int satval = (1 << satpos) - 1;
if (cond != al) {
b(NegateCondition(cond), &done); // Skip saturate if !condition.
}
if (!(src.is_reg() && dst.is(src.rm()))) {
mov(dst, src);
}
tst(dst, Operand(~satval));
b(eq, &done);
mov(dst, Operand(0, RelocInfo::NONE), LeaveCC, mi); // 0 if negative.
mov(dst, Operand(satval), LeaveCC, pl); // satval if positive.
bind(&done);
} else {
usat(dst, satpos, src, cond);
}
}
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);
}
void MacroAssembler::StoreRoot(Register source,
Heap::RootListIndex index,
Condition cond) {
str(source, MemOperand(roots, index << kPointerSizeLog2), cond);
}
void MacroAssembler::RecordWriteHelper(Register object,
Register address,
Register scratch) {
if (FLAG_debug_code) {
// Check that the object is not in new space.
Label not_in_new_space;
InNewSpace(object, scratch, ne, &not_in_new_space);
Abort("new-space object passed to RecordWriteHelper");
bind(&not_in_new_space);
}
// Calculate page address.
Bfc(object, 0, kPageSizeBits);
// Calculate region number.
Ubfx(address, address, Page::kRegionSizeLog2,
kPageSizeBits - Page::kRegionSizeLog2);
// Mark region dirty.
ldr(scratch, MemOperand(object, Page::kDirtyFlagOffset));
mov(ip, Operand(1));
orr(scratch, scratch, Operand(ip, LSL, address));
str(scratch, MemOperand(object, Page::kDirtyFlagOffset));
}
void MacroAssembler::InNewSpace(Register object,
Register scratch,
Condition cc,
Label* branch) {
ASSERT(cc == eq || cc == ne);
and_(scratch, object, Operand(ExternalReference::new_space_mask()));
cmp(scratch, Operand(ExternalReference::new_space_start()));
b(cc, branch);
}
// 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,
Operand offset,
Register scratch0,
Register scratch1) {
// 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) && !scratch0.is(cp) && !scratch1.is(cp));
Label done;
// First, test that the object is not in the new space. We cannot set
// region marks for new space pages.
InNewSpace(object, scratch0, eq, &done);
// Add offset into the object.
add(scratch0, object, offset);
// Record the actual write.
RecordWriteHelper(object, scratch0, scratch1);
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(BitCast<int32_t>(kZapValue)));
mov(scratch0, Operand(BitCast<int32_t>(kZapValue)));
mov(scratch1, Operand(BitCast<int32_t>(kZapValue)));
}
}
// Will clobber 4 registers: object, address, scratch, ip. The
// register 'object' contains a heap object pointer. The heap object
// tag is shifted away.
void MacroAssembler::RecordWrite(Register object,
Register address,
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) && !address.is(cp) && !scratch.is(cp));
Label done;
// First, test that the object is not in the new space. We cannot set
// region marks for new space pages.
InNewSpace(object, scratch, eq, &done);
// Record the actual write.
RecordWriteHelper(object, address, scratch);
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(BitCast<int32_t>(kZapValue)));
mov(address, Operand(BitCast<int32_t>(kZapValue)));
mov(scratch, Operand(BitCast<int32_t>(kZapValue)));
}
}
void MacroAssembler::Ldrd(Register dst1, Register dst2,
const MemOperand& src, Condition cond) {
ASSERT(src.rm().is(no_reg));
ASSERT(!dst1.is(lr)); // r14.
ASSERT_EQ(0, dst1.code() % 2);
ASSERT_EQ(dst1.code() + 1, dst2.code());
// Generate two ldr instructions if ldrd is not available.
if (CpuFeatures::IsSupported(ARMv7)) {
CpuFeatures::Scope scope(ARMv7);
ldrd(dst1, dst2, src, cond);
} else {
MemOperand src2(src);
src2.set_offset(src2.offset() + 4);
if (dst1.is(src.rn())) {
ldr(dst2, src2, cond);
ldr(dst1, src, cond);
} else {
ldr(dst1, src, cond);
ldr(dst2, src2, cond);
}
}
}
void MacroAssembler::Strd(Register src1, Register src2,
const MemOperand& dst, Condition cond) {
ASSERT(dst.rm().is(no_reg));
ASSERT(!src1.is(lr)); // r14.
ASSERT_EQ(0, src1.code() % 2);
ASSERT_EQ(src1.code() + 1, src2.code());
// Generate two str instructions if strd is not available.
if (CpuFeatures::IsSupported(ARMv7)) {
CpuFeatures::Scope scope(ARMv7);
strd(src1, src2, dst, cond);
} else {
MemOperand dst2(dst);
dst2.set_offset(dst2.offset() + 4);
str(src1, dst, cond);
str(src2, dst2, cond);
}
}
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() {
// 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));
// Prepare the stack to be aligned when calling into C. After this point there
// are 5 pushes before the call into C, so the stack needs to be aligned after
// 5 pushes.
int frame_alignment = ActivationFrameAlignment();
int frame_alignment_mask = frame_alignment - 1;
if (frame_alignment != kPointerSize) {
// The following code needs to be more general if this assert does not hold.
ASSERT(frame_alignment == 2 * kPointerSize);
// With 5 pushes left the frame must be unaligned at this point.
mov(r7, Operand(Smi::FromInt(0)));
tst(sp, Operand((frame_alignment - kPointerSize) & frame_alignment_mask));
push(r7, eq); // Push if aligned to make it unaligned.
}
// 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));
}
void MacroAssembler::InitializeNewString(Register string,
Register length,
Heap::RootListIndex map_index,
Register scratch1,
Register scratch2) {
mov(scratch1, Operand(length, LSL, kSmiTagSize));
LoadRoot(scratch2, map_index);
str(scratch1, FieldMemOperand(string, String::kLengthOffset));
mov(scratch1, Operand(String::kEmptyHashField));
str(scratch2, FieldMemOperand(string, HeapObject::kMapOffset));
str(scratch1, FieldMemOperand(string, String::kHashFieldOffset));
}
int MacroAssembler::ActivationFrameAlignment() {
#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.
return 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 this is controlled from a
// flag.
return FLAG_sim_stack_alignment;
#endif // defined(V8_HOST_ARCH_ARM)
}
void MacroAssembler::LeaveExitFrame() {
// Clear top frame.
mov(r3, Operand(0, RelocInfo::NONE));
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));
mov(expected_reg, Operand(expected_reg, ASR, kSmiTagSize));
ldr(code_reg,
FieldMemOperand(r1, JSFunction::kCodeEntryOffset));
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::DebugBreak() {
ASSERT(allow_stub_calls());
mov(r0, Operand(0, RelocInfo::NONE));
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, RelocInfo::NONE)); // 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));
}
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, RelocInfo::NONE));
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) {
if (!FLAG_inline_new) {
if (FLAG_debug_code) {
// Trash the registers to simulate an allocation failure.
mov(result, Operand(0x7091));
mov(scratch1, Operand(0x7191));
mov(scratch2, Operand(0x7291));
}
jmp(gc_required);
return;
}
ASSERT(!result.is(scratch1));
ASSERT(!scratch1.is(scratch2));
// Make object size into bytes.
if ((flags & SIZE_IN_WORDS) != 0) {
object_size *= kPointerSize;
}
ASSERT_EQ(0, object_size & kObjectAlignmentMask);
// 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));
cmp(result, Operand(scratch2));
b(hi, gc_required);
str(result, MemOperand(scratch1));
// Tag and adjust back to start of new object.
if ((flags & TAG_OBJECT) != 0) {
sub(result, result, Operand(object_size - kHeapObjectTag));
} else {
sub(result, result, Operand(object_size));
}
}
void MacroAssembler::AllocateInNewSpace(Register object_size,
Register result,
Register scratch1,
Register scratch2,
Label* gc_required,
AllocationFlags flags) {
if (!FLAG_inline_new) {
if (FLAG_debug_code) {
// Trash the registers to simulate an allocation failure.
mov(result, Operand(0x7091));
mov(scratch1, Operand(0x7191));
mov(scratch2, Operand(0x7291));
}
jmp(gc_required);
return;
}
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));
if ((flags & SIZE_IN_WORDS) != 0) {
add(result, result, Operand(object_size, LSL, kPointerSizeLog2));
} else {
add(result, result, Operand(object_size));
}
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.
if ((flags & SIZE_IN_WORDS) != 0) {
sub(result, result, Operand(object_size, LSL, kPointerSizeLog2));
} else {
sub(result, result, Operand(object_size));
}
// 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));
and_(scratch1, scratch1, Operand(~kObjectAlignmentMask));
// Allocate two-byte string in new space.
AllocateInNewSpace(scratch1,
result,
scratch2,
scratch3,
gc_required,
TAG_OBJECT);
// Set the map, length and hash field.
InitializeNewString(result,
length,
Heap::kStringMapRootIndex,
scratch1,
scratch2);
}
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));
and_(scratch1, scratch1, Operand(~kObjectAlignmentMask));
// Allocate ASCII string in new space.
AllocateInNewSpace(scratch1,
result,
scratch2,
scratch3,
gc_required,
TAG_OBJECT);
// Set the map, length and hash field.
InitializeNewString(result,
length,
Heap::kAsciiStringMapRootIndex,
scratch1,
scratch2);
}
void MacroAssembler::AllocateTwoByteConsString(Register result,
Register length,
Register scratch1,
Register scratch2,
Label* gc_required) {
AllocateInNewSpace(ConsString::kSize,
result,
scratch1,
scratch2,
gc_required,
TAG_OBJECT);
InitializeNewString(result,
length,
Heap::kConsStringMapRootIndex,
scratch1,
scratch2);
}
void MacroAssembler::AllocateAsciiConsString(Register result,
Register length,
Register scratch1,
Register scratch2,
Label* gc_required) {
AllocateInNewSpace(ConsString::kSize,
result,
scratch1,
scratch2,
gc_required,
TAG_OBJECT);
InitializeNewString(result,
length,
Heap::kConsAsciiStringMapRootIndex,
scratch1,
scratch2);
}
void MacroAssembler::CompareObjectType(Register object,
Register map,
Register type_reg,
InstanceType type) {
ldr(map, FieldMemOperand(object, 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::CheckMap(Register obj,
Register scratch,
Heap::RootListIndex index,
Label* fail,
bool is_heap_object) {
if (!is_heap_object) {
BranchOnSmi(obj, fail);
}
ldr(scratch, FieldMemOperand(obj, HeapObject::kMapOffset));
LoadRoot(ip, index);
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::IllegalOperation(int num_arguments) {
if (num_arguments > 0) {
add(sp, sp, Operand(num_arguments * kPointerSize));
}
LoadRoot(r0, Heap::kUndefinedValueRootIndex);
}
void MacroAssembler::IndexFromHash(Register hash, Register index) {
// If the hash field contains an array index pick it out. The assert checks
// that the constants for the maximum number of digits for an array index
// cached in the hash field and the number of bits reserved for it does not
// conflict.
ASSERT(TenToThe(String::kMaxCachedArrayIndexLength) <
(1 << String::kArrayIndexValueBits));
// We want the smi-tagged index in key. kArrayIndexValueMask has zeros in
// the low kHashShift bits.
STATIC_ASSERT(kSmiTag == 0);
Ubfx(hash, hash, String::kHashShift, String::kArrayIndexValueBits);
mov(index, Operand(hash, LSL, kSmiTagSize));
}
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_f64_s32(d7, s15);
vmov(outLowReg, outHighReg, d7);
}
void MacroAssembler::ObjectToDoubleVFPRegister(Register object,
DwVfpRegister result,
Register scratch1,
Register scratch2,
Register heap_number_map,
SwVfpRegister scratch3,
Label* not_number,
ObjectToDoubleFlags flags) {
Label done;
if ((flags & OBJECT_NOT_SMI) == 0) {
Label not_smi;
BranchOnNotSmi(object, &not_smi);
// Remove smi tag and convert to double.
mov(scratch1, Operand(object, ASR, kSmiTagSize));
vmov(scratch3, scratch1);
vcvt_f64_s32(result, scratch3);
b(&done);
bind(&not_smi);
}
// Check for heap number and load double value from it.
ldr(scratch1, FieldMemOperand(object, HeapObject::kMapOffset));
sub(scratch2, object, Operand(kHeapObjectTag));
cmp(scratch1, heap_number_map);
b(ne, not_number);
if ((flags & AVOID_NANS_AND_INFINITIES) != 0) {
// If exponent is all ones the number is either a NaN or +/-Infinity.
ldr(scratch1, FieldMemOperand(object, HeapNumber::kExponentOffset));
Sbfx(scratch1,
scratch1,
HeapNumber::kExponentShift,
HeapNumber::kExponentBits);
// All-one value sign extend to -1.
cmp(scratch1, Operand(-1));
b(eq, not_number);
}
vldr(result, scratch2, HeapNumber::kValueOffset);
bind(&done);
}
void MacroAssembler::SmiToDoubleVFPRegister(Register smi,
DwVfpRegister value,
Register scratch1,
SwVfpRegister scratch2) {
mov(scratch1, Operand(smi, ASR, kSmiTagSize));
vmov(scratch2, scratch1);
vcvt_f64_s32(value, scratch2);
}
// Tries to get a signed int32 out of a double precision floating point heap
// number. Rounds towards 0. Branch to 'not_int32' if the double is out of the
// 32bits signed integer range.
void MacroAssembler::ConvertToInt32(Register source,
Register dest,
Register scratch,
Register scratch2,
Label *not_int32) {
if (CpuFeatures::IsSupported(VFP3)) {
CpuFeatures::Scope scope(VFP3);
sub(scratch, source, Operand(kHeapObjectTag));
vldr(d0, scratch, HeapNumber::kValueOffset);
vcvt_s32_f64(s0, d0);
vmov(dest, s0);
// Signed vcvt instruction will saturate to the minimum (0x80000000) or
// maximun (0x7fffffff) signed 32bits integer when the double is out of
// range. When substracting one, the minimum signed integer becomes the
// maximun signed integer.
sub(scratch, dest, Operand(1));
cmp(scratch, Operand(LONG_MAX - 1));
// If equal then dest was LONG_MAX, if greater dest was LONG_MIN.
b(ge, not_int32);
} else {
// This code is faster for doubles that are in the ranges -0x7fffffff to
// -0x40000000 or 0x40000000 to 0x7fffffff. This corresponds almost to
// the range of signed int32 values that are not Smis. Jumps to the label
// 'not_int32' if the double isn't in the range -0x80000000.0 to
// 0x80000000.0 (excluding the endpoints).
Label right_exponent, done;
// Get exponent word.
ldr(scratch, FieldMemOperand(source, HeapNumber::kExponentOffset));
// Get exponent alone in scratch2.
Ubfx(scratch2,
scratch,
HeapNumber::kExponentShift,
HeapNumber::kExponentBits);
// Load dest with zero. We use this either for the final shift or
// for the answer.
mov(dest, Operand(0, RelocInfo::NONE));
// Check whether the exponent matches a 32 bit signed int that is not a Smi.
// A non-Smi integer is 1.xxx * 2^30 so the exponent is 30 (biased). This is
// the exponent that we are fastest at and also the highest exponent we can
// handle here.
const uint32_t non_smi_exponent = HeapNumber::kExponentBias + 30;
// The non_smi_exponent, 0x41d, is too big for ARM's immediate field so we
// split it up to avoid a constant pool entry. You can't do that in general
// for cmp because of the overflow flag, but we know the exponent is in the
// range 0-2047 so there is no overflow.
int fudge_factor = 0x400;
sub(scratch2, scratch2, Operand(fudge_factor));
cmp(scratch2, Operand(non_smi_exponent - fudge_factor));
// If we have a match of the int32-but-not-Smi exponent then skip some
// logic.
b(eq, &right_exponent);
// If the exponent is higher than that then go to slow case. This catches
// numbers that don't fit in a signed int32, infinities and NaNs.
b(gt, not_int32);
// We know the exponent is smaller than 30 (biased). If it is less than
// 0 (biased) then the number is smaller in magnitude than 1.0 * 2^0, ie
// it rounds to zero.
const uint32_t zero_exponent = HeapNumber::kExponentBias + 0;
sub(scratch2, scratch2, Operand(zero_exponent - fudge_factor), SetCC);
// Dest already has a Smi zero.
b(lt, &done);
// We have an exponent between 0 and 30 in scratch2. Subtract from 30 to
// get how much to shift down.
rsb(dest, scratch2, Operand(30));
bind(&right_exponent);
// Get the top bits of the mantissa.
and_(scratch2, scratch, Operand(HeapNumber::kMantissaMask));
// Put back the implicit 1.
orr(scratch2, scratch2, Operand(1 << HeapNumber::kExponentShift));
// Shift up the mantissa bits to take up the space the exponent used to
// take. We just orred in the implicit bit so that took care of one and
// we want to leave the sign bit 0 so we subtract 2 bits from the shift
// distance.
const int shift_distance = HeapNumber::kNonMantissaBitsInTopWord - 2;
mov(scratch2, Operand(scratch2, LSL, shift_distance));
// Put sign in zero flag.
tst(scratch, Operand(HeapNumber::kSignMask));
// Get the second half of the double. For some exponents we don't
// actually need this because the bits get shifted out again, but
// it's probably slower to test than just to do it.
ldr(scratch, FieldMemOperand(source, HeapNumber::kMantissaOffset));
// Shift down 22 bits to get the last 10 bits.
orr(scratch, scratch2, Operand(scratch, LSR, 32 - shift_distance));
// Move down according to the exponent.
mov(dest, Operand(scratch, LSR, dest));
// Fix sign if sign bit was set.
rsb(dest, dest, Operand(0, RelocInfo::NONE), LeaveCC, ne);
bind(&done);
}
}
void MacroAssembler::GetLeastBitsFromSmi(Register dst,
Register src,
int num_least_bits) {
if (CpuFeatures::IsSupported(ARMv7)) {
ubfx(dst, src, kSmiTagSize, num_least_bits);
} 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::TailCallExternalReference(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));
JumpToExternalReference(ext);
}
void MacroAssembler::TailCallRuntime(Runtime::FunctionId fid,
int num_arguments,
int result_size) {
TailCallExternalReference(ExternalReference(fid), num_arguments, result_size);
}
void MacroAssembler::JumpToExternalReference(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::GetBuiltinFunction(Register target,
Builtins::JavaScript id) {
// Load the builtins object into target register.
ldr(target, MemOperand(cp, Context::SlotOffset(Context::GLOBAL_INDEX)));
ldr(target, FieldMemOperand(target, GlobalObject::kBuiltinsOffset));
// Load the JavaScript builtin function from the builtins object.
ldr(target, FieldMemOperand(target,
JSBuiltinsObject::OffsetOfFunctionWithId(id)));
}
void MacroAssembler::GetBuiltinEntry(Register target, Builtins::JavaScript id) {
ASSERT(!target.is(r1));
GetBuiltinFunction(r1, id);
// Load the code entry point from the builtins object.
ldr(target, FieldMemOperand(r1, JSFunction::kCodeEntryOffset));
}
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::AssertRegisterIsRoot(Register reg,
Heap::RootListIndex index) {
if (FLAG_debug_code) {
LoadRoot(ip, index);
cmp(reg, ip);
Check(eq, "Register did not match expected root");
}
}
void MacroAssembler::AssertFastElements(Register elements) {
if (FLAG_debug_code) {
ASSERT(!elements.is(ip));
Label ok;
push(elements);
ldr(elements, FieldMemOperand(elements, HeapObject::kMapOffset));
LoadRoot(ip, Heap::kFixedArrayMapRootIndex);
cmp(elements, ip);
b(eq, &ok);
LoadRoot(ip, Heap::kFixedCOWArrayMapRootIndex);
cmp(elements, ip);
b(eq, &ok);
Abort("JSObject with fast elements map has slow elements");
bind(&ok);
pop(elements);
}
}
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) {
Label abort_start;
bind(&abort_start);
// 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
if (is_const_pool_blocked()) {
// If the calling code cares about the exact number of
// instructions generated, we insert padding here to keep the size
// of the Abort macro constant.
static const int kExpectedAbortInstructions = 10;
int abort_instructions = InstructionsGeneratedSince(&abort_start);
ASSERT(abort_instructions <= kExpectedAbortInstructions);
while (abort_instructions++ < kExpectedAbortInstructions) {
nop();
}
}
}
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::AbortIfSmi(Register object) {
ASSERT_EQ(0, kSmiTag);
tst(object, Operand(kSmiTagMask));
Assert(ne, "Operand is a 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));
JumpIfBothInstanceTypesAreNotSequentialAscii(scratch1,
scratch2,
scratch1,
scratch2,
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);
}
// Allocates a heap number or jumps to the need_gc label if the young space
// is full and a scavenge is needed.
void MacroAssembler::AllocateHeapNumber(Register result,
Register scratch1,
Register scratch2,
Register heap_number_map,
Label* gc_required) {
// Allocate an object in the heap for the heap number and tag it as a heap
// object.
AllocateInNewSpace(HeapNumber::kSize,
result,
scratch1,
scratch2,
gc_required,
TAG_OBJECT);
// Store heap number map in the allocated object.
AssertRegisterIsRoot(heap_number_map, Heap::kHeapNumberMapRootIndex);
str(heap_number_map, FieldMemOperand(result, HeapObject::kMapOffset));
}
void MacroAssembler::AllocateHeapNumberWithValue(Register result,
DwVfpRegister value,
Register scratch1,
Register scratch2,
Register heap_number_map,
Label* gc_required) {
AllocateHeapNumber(result, scratch1, scratch2, heap_number_map, gc_required);
sub(scratch1, result, Operand(kHeapObjectTag));
vstr(value, scratch1, HeapNumber::kValueOffset);
}
// Copies a fixed number of fields of heap objects from src to dst.
void MacroAssembler::CopyFields(Register dst,
Register src,
RegList temps,
int field_count) {
// At least one bit set in the first 15 registers.
ASSERT((temps & ((1 << 15) - 1)) != 0);
ASSERT((temps & dst.bit()) == 0);
ASSERT((temps & src.bit()) == 0);
// Primitive implementation using only one temporary register.
Register tmp = no_reg;
// Find a temp register in temps list.
for (int i = 0; i < 15; i++) {
if ((temps & (1 << i)) != 0) {
tmp.set_code(i);
break;
}
}
ASSERT(!tmp.is(no_reg));
for (int i = 0; i < field_count; i++) {
ldr(tmp, FieldMemOperand(src, i * kPointerSize));
str(tmp, FieldMemOperand(dst, i * kPointerSize));
}
}
void MacroAssembler::CountLeadingZeros(Register zeros, // Answer.
Register source, // Input.
Register scratch) {
ASSERT(!zeros.is(source) || !source.is(zeros));
ASSERT(!zeros.is(scratch));
ASSERT(!scratch.is(ip));
ASSERT(!source.is(ip));
ASSERT(!zeros.is(ip));
#ifdef CAN_USE_ARMV5_INSTRUCTIONS
clz(zeros, source); // This instruction is only supported after ARM5.
#else
mov(zeros, Operand(0, RelocInfo::NONE));
Move(scratch, source);
// Top 16.
tst(scratch, Operand(0xffff0000));
add(zeros, zeros, Operand(16), LeaveCC, eq);
mov(scratch, Operand(scratch, LSL, 16), LeaveCC, eq);
// Top 8.
tst(scratch, Operand(0xff000000));
add(zeros, zeros, Operand(8), LeaveCC, eq);
mov(scratch, Operand(scratch, LSL, 8), LeaveCC, eq);
// Top 4.
tst(scratch, Operand(0xf0000000));
add(zeros, zeros, Operand(4), LeaveCC, eq);
mov(scratch, Operand(scratch, LSL, 4), LeaveCC, eq);
// Top 2.
tst(scratch, Operand(0xc0000000));
add(zeros, zeros, Operand(2), LeaveCC, eq);
mov(scratch, Operand(scratch, LSL, 2), LeaveCC, eq);
// Top bit.
tst(scratch, Operand(0x80000000u));
add(zeros, zeros, Operand(1), LeaveCC, eq);
#endif
}
void MacroAssembler::JumpIfBothInstanceTypesAreNotSequentialAscii(
Register first,
Register second,
Register scratch1,
Register scratch2,
Label* failure) {
int kFlatAsciiStringMask =
kIsNotStringMask | kStringEncodingMask | kStringRepresentationMask;
int kFlatAsciiStringTag = ASCII_STRING_TYPE;
and_(scratch1, first, Operand(kFlatAsciiStringMask));
and_(scratch2, second, Operand(kFlatAsciiStringMask));
cmp(scratch1, Operand(kFlatAsciiStringTag));
// Ignore second test if first test failed.
cmp(scratch2, Operand(kFlatAsciiStringTag), eq);
b(ne, failure);
}
void MacroAssembler::JumpIfInstanceTypeIsNotSequentialAscii(Register type,
Register scratch,
Label* failure) {
int kFlatAsciiStringMask =
kIsNotStringMask | kStringEncodingMask | kStringRepresentationMask;
int kFlatAsciiStringTag = ASCII_STRING_TYPE;
and_(scratch, type, Operand(kFlatAsciiStringMask));
cmp(scratch, Operand(kFlatAsciiStringTag));
b(ne, failure);
}
void MacroAssembler::PrepareCallCFunction(int num_arguments, Register scratch) {
int frame_alignment = ActivationFrameAlignment();
// Up to four simple arguments are passed in registers r0..r3.
int stack_passed_arguments = (num_arguments <= 4) ? 0 : num_arguments - 4;
if (frame_alignment > kPointerSize) {
// Make stack end at alignment and make room for num_arguments - 4 words
// and the original value of sp.
mov(scratch, sp);
sub(sp, sp, Operand((stack_passed_arguments + 1) * kPointerSize));
ASSERT(IsPowerOf2(frame_alignment));
and_(sp, sp, Operand(-frame_alignment));
str(scratch, MemOperand(sp, stack_passed_arguments * kPointerSize));
} else {
sub(sp, sp, Operand(stack_passed_arguments * kPointerSize));
}
}
void MacroAssembler::CallCFunction(ExternalReference function,
int num_arguments) {
mov(ip, Operand(function));
CallCFunction(ip, num_arguments);
}
void MacroAssembler::CallCFunction(Register function, int num_arguments) {
// Make sure that the stack is aligned before calling a C function unless
// running in the simulator. The simulator has its own alignment check which
// provides more information.
#if defined(V8_HOST_ARCH_ARM)
if (FLAG_debug_code) {
int frame_alignment = OS::ActivationFrameAlignment();
int frame_alignment_mask = frame_alignment - 1;
if (frame_alignment > kPointerSize) {
ASSERT(IsPowerOf2(frame_alignment));
Label alignment_as_expected;
tst(sp, Operand(frame_alignment_mask));
b(eq, &alignment_as_expected);
// Don't use Check here, as it will call Runtime_Abort possibly
// re-entering here.
stop("Unexpected alignment");
bind(&alignment_as_expected);
}
}
#endif
// Just call directly. The function called cannot cause a GC, or
// allow preemption, so the return address in the link register
// stays correct.
Call(function);
int stack_passed_arguments = (num_arguments <= 4) ? 0 : num_arguments - 4;
if (OS::ActivationFrameAlignment() > kPointerSize) {
ldr(sp, MemOperand(sp, stack_passed_arguments * kPointerSize));
} else {
add(sp, sp, Operand(stack_passed_arguments * sizeof(kPointerSize)));
}
}
#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
#endif // V8_TARGET_ARCH_ARM