lukechilds
/
node
mirror of https://github.com/lukechilds/node.git
1
0
Fork 0
Code Issues Projects Releases Wiki Activity
You can not select more than 25 topics Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
3597 Commits
131 Branches
446 Tags
325 MiB
 
 
 
 
 
 
Tree: 6afdca885a
Branches Tags
${ item.name }
Create tag ${ searchTerm }
Create branch ${ searchTerm }
from '6afdca885a'
${ noResults }
node/deps/v8/src/arm/assembler-arm.cc

2756 lines
85 KiB
Raw Blame History

// Copyright (c) 1994-2006 Sun Microsystems Inc.
// 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.
//
// - Redistribution 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 Sun Microsystems or the names of 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.
// The original source code covered by the above license above has been
// modified significantly by Google Inc.
// Copyright 2010 the V8 project authors. All rights reserved.
#include "v8.h"
#if defined(V8_TARGET_ARCH_ARM)
#include "arm/assembler-arm-inl.h"
#include "serialize.h"
namespace v8 {
namespace internal {
// Safe default is no features.
unsigned CpuFeatures::supported_ = 0;
unsigned CpuFeatures::enabled_ = 0;
unsigned CpuFeatures::found_by_runtime_probing_ = 0;
#ifdef __arm__
static uint64_t CpuFeaturesImpliedByCompiler() {
uint64_t answer = 0;
#ifdef CAN_USE_ARMV7_INSTRUCTIONS
answer |= 1u << ARMv7;
#endif // def CAN_USE_ARMV7_INSTRUCTIONS
// If the compiler is allowed to use VFP then we can use VFP too in our code
// generation even when generating snapshots. This won't work for cross
// compilation.
#if defined(__VFP_FP__) && !defined(__SOFTFP__)
answer |= 1u << VFP3;
#endif // defined(__VFP_FP__) && !defined(__SOFTFP__)
#ifdef CAN_USE_VFP_INSTRUCTIONS
answer |= 1u << VFP3;
#endif // def CAN_USE_VFP_INSTRUCTIONS
return answer;
}
#endif // def __arm__
void CpuFeatures::Probe(bool portable) {
#ifndef __arm__
// For the simulator=arm build, use VFP when FLAG_enable_vfp3 is enabled.
if (FLAG_enable_vfp3) {
supported_ |= 1u << VFP3;
}
// For the simulator=arm build, use ARMv7 when FLAG_enable_armv7 is enabled
if (FLAG_enable_armv7) {
supported_ |= 1u << ARMv7;
}
#else // def __arm__
if (portable && Serializer::enabled()) {
supported_ |= OS::CpuFeaturesImpliedByPlatform();
supported_ |= CpuFeaturesImpliedByCompiler();
return; // No features if we might serialize.
}
if (OS::ArmCpuHasFeature(VFP3)) {
// This implementation also sets the VFP flags if
// runtime detection of VFP returns true.
supported_ |= 1u << VFP3;
found_by_runtime_probing_ |= 1u << VFP3;
}
if (OS::ArmCpuHasFeature(ARMv7)) {
supported_ |= 1u << ARMv7;
found_by_runtime_probing_ |= 1u << ARMv7;
}
if (!portable) found_by_runtime_probing_ = 0;
#endif
}
// -----------------------------------------------------------------------------
// Implementation of RelocInfo
const int RelocInfo::kApplyMask = 0;
bool RelocInfo::IsCodedSpecially() {
// The deserializer needs to know whether a pointer is specially coded. Being
// specially coded on ARM means that it is a movw/movt instruction. We don't
// generate those yet.
return false;
}
void RelocInfo::PatchCode(byte* instructions, int instruction_count) {
// Patch the code at the current address with the supplied instructions.
Instr* pc = reinterpret_cast<Instr*>(pc_);
Instr* instr = reinterpret_cast<Instr*>(instructions);
for (int i = 0; i < instruction_count; i++) {
*(pc + i) = *(instr + i);
}
// Indicate that code has changed.
CPU::FlushICache(pc_, instruction_count * Assembler::kInstrSize);
}
// Patch the code at the current PC with a call to the target address.
// Additional guard instructions can be added if required.
void RelocInfo::PatchCodeWithCall(Address target, int guard_bytes) {
// Patch the code at the current address with a call to the target.
UNIMPLEMENTED();
}
// -----------------------------------------------------------------------------
// Implementation of Operand and MemOperand
// See assembler-arm-inl.h for inlined constructors
Operand::Operand(Handle<Object> handle) {
rm_ = no_reg;
// Verify all Objects referred by code are NOT in new space.
Object* obj = *handle;
ASSERT(!Heap::InNewSpace(obj));
if (obj->IsHeapObject()) {
imm32_ = reinterpret_cast<intptr_t>(handle.location());
rmode_ = RelocInfo::EMBEDDED_OBJECT;
} else {
// no relocation needed
imm32_ = reinterpret_cast<intptr_t>(obj);
rmode_ = RelocInfo::NONE;
}
}
Operand::Operand(Register rm, ShiftOp shift_op, int shift_imm) {
ASSERT(is_uint5(shift_imm));
ASSERT(shift_op != ROR || shift_imm != 0); // use RRX if you mean it
rm_ = rm;
rs_ = no_reg;
shift_op_ = shift_op;
shift_imm_ = shift_imm & 31;
if (shift_op == RRX) {
// encoded as ROR with shift_imm == 0
ASSERT(shift_imm == 0);
shift_op_ = ROR;
shift_imm_ = 0;
}
}
Operand::Operand(Register rm, ShiftOp shift_op, Register rs) {
ASSERT(shift_op != RRX);
rm_ = rm;
rs_ = no_reg;
shift_op_ = shift_op;
rs_ = rs;
}
MemOperand::MemOperand(Register rn, int32_t offset, AddrMode am) {
rn_ = rn;
rm_ = no_reg;
offset_ = offset;
am_ = am;
}
MemOperand::MemOperand(Register rn, Register rm, AddrMode am) {
rn_ = rn;
rm_ = rm;
shift_op_ = LSL;
shift_imm_ = 0;
am_ = am;
}
MemOperand::MemOperand(Register rn, Register rm,
ShiftOp shift_op, int shift_imm, AddrMode am) {
ASSERT(is_uint5(shift_imm));
rn_ = rn;
rm_ = rm;
shift_op_ = shift_op;
shift_imm_ = shift_imm & 31;
am_ = am;
}
// -----------------------------------------------------------------------------
// Specific instructions, constants, and masks.
// add(sp, sp, 4) instruction (aka Pop())
const Instr kPopInstruction =
al | PostIndex | 4 | LeaveCC | I | sp.code() * B16 | sp.code() * B12;
// str(r, MemOperand(sp, 4, NegPreIndex), al) instruction (aka push(r))
// register r is not encoded.
const Instr kPushRegPattern =
al | B26 | 4 | NegPreIndex | sp.code() * B16;
// ldr(r, MemOperand(sp, 4, PostIndex), al) instruction (aka pop(r))
// register r is not encoded.
const Instr kPopRegPattern =
al | B26 | L | 4 | PostIndex | sp.code() * B16;
// mov lr, pc
const Instr kMovLrPc = al | MOV | pc.code() | lr.code() * B12;
// ldr rd, [pc, #offset]
const Instr kLdrPCMask = kCondMask | 15 * B24 | 7 * B20 | 15 * B16;
const Instr kLdrPCPattern = al | 5 * B24 | L | pc.code() * B16;
// blxcc rm
const Instr kBlxRegMask =
15 * B24 | 15 * B20 | 15 * B16 | 15 * B12 | 15 * B8 | 15 * B4;
const Instr kBlxRegPattern =
B24 | B21 | 15 * B16 | 15 * B12 | 15 * B8 | BLX;
const Instr kMovMvnMask = 0x6d * B21 | 0xf * B16;
const Instr kMovMvnPattern = 0xd * B21;
const Instr kMovMvnFlip = B22;
const Instr kMovLeaveCCMask = 0xdff * B16;
const Instr kMovLeaveCCPattern = 0x1a0 * B16;
const Instr kMovwMask = 0xff * B20;
const Instr kMovwPattern = 0x30 * B20;
const Instr kMovwLeaveCCFlip = 0x5 * B21;
const Instr kCmpCmnMask = 0xdd * B20 | 0xf * B12;
const Instr kCmpCmnPattern = 0x15 * B20;
const Instr kCmpCmnFlip = B21;
const Instr kAddSubFlip = 0x6 * B21;
const Instr kAndBicFlip = 0xe * B21;
// A mask for the Rd register for push, pop, ldr, str instructions.
const Instr kLdrRegFpOffsetPattern =
al | B26 | L | Offset | fp.code() * B16;
const Instr kStrRegFpOffsetPattern =
al | B26 | Offset | fp.code() * B16;
const Instr kLdrRegFpNegOffsetPattern =
al | B26 | L | NegOffset | fp.code() * B16;
const Instr kStrRegFpNegOffsetPattern =
al | B26 | NegOffset | fp.code() * B16;
const Instr kLdrStrInstrTypeMask = 0xffff0000;
const Instr kLdrStrInstrArgumentMask = 0x0000ffff;
const Instr kLdrStrOffsetMask = 0x00000fff;
// Spare buffer.
static const int kMinimalBufferSize = 4*KB;
static byte* spare_buffer_ = NULL;
Assembler::Assembler(void* buffer, int buffer_size)
: positions_recorder_(this),
allow_peephole_optimization_(false) {
allow_peephole_optimization_ = FLAG_peephole_optimization;
if (buffer == NULL) {
// Do our own buffer management.
if (buffer_size <= kMinimalBufferSize) {
buffer_size = kMinimalBufferSize;
if (spare_buffer_ != NULL) {
buffer = spare_buffer_;
spare_buffer_ = NULL;
}
}
if (buffer == NULL) {
buffer_ = NewArray<byte>(buffer_size);
} else {
buffer_ = static_cast<byte*>(buffer);
}
buffer_size_ = buffer_size;
own_buffer_ = true;
} else {
// Use externally provided buffer instead.
ASSERT(buffer_size > 0);
buffer_ = static_cast<byte*>(buffer);
buffer_size_ = buffer_size;
own_buffer_ = false;
}
// Setup buffer pointers.
ASSERT(buffer_ != NULL);
pc_ = buffer_;
reloc_info_writer.Reposition(buffer_ + buffer_size, pc_);
num_prinfo_ = 0;
next_buffer_check_ = 0;
const_pool_blocked_nesting_ = 0;
no_const_pool_before_ = 0;
last_const_pool_end_ = 0;
last_bound_pos_ = 0;
}
Assembler::~Assembler() {
ASSERT(const_pool_blocked_nesting_ == 0);
if (own_buffer_) {
if (spare_buffer_ == NULL && buffer_size_ == kMinimalBufferSize) {
spare_buffer_ = buffer_;
} else {
DeleteArray(buffer_);
}
}
}
void Assembler::GetCode(CodeDesc* desc) {
// Emit constant pool if necessary.
CheckConstPool(true, false);
ASSERT(num_prinfo_ == 0);
// Setup code descriptor.
desc->buffer = buffer_;
desc->buffer_size = buffer_size_;
desc->instr_size = pc_offset();
desc->reloc_size = (buffer_ + buffer_size_) - reloc_info_writer.pos();
}
void Assembler::Align(int m) {
ASSERT(m >= 4 && IsPowerOf2(m));
while ((pc_offset() & (m - 1)) != 0) {
nop();
}
}
void Assembler::CodeTargetAlign() {
// Preferred alignment of jump targets on some ARM chips.
Align(8);
}
Condition Assembler::GetCondition(Instr instr) {
return Instruction::ConditionField(instr);
}
bool Assembler::IsBranch(Instr instr) {
return (instr & (B27 | B25)) == (B27 | B25);
}
int Assembler::GetBranchOffset(Instr instr) {
ASSERT(IsBranch(instr));
// Take the jump offset in the lower 24 bits, sign extend it and multiply it
// with 4 to get the offset in bytes.
return ((instr & kImm24Mask) << 8) >> 6;
}
bool Assembler::IsLdrRegisterImmediate(Instr instr) {
return (instr & (B27 | B26 | B25 | B22 | B20)) == (B26 | B20);
}
int Assembler::GetLdrRegisterImmediateOffset(Instr instr) {
ASSERT(IsLdrRegisterImmediate(instr));
bool positive = (instr & B23) == B23;
int offset = instr & kOff12Mask; // Zero extended offset.
return positive ? offset : -offset;
}
Instr Assembler::SetLdrRegisterImmediateOffset(Instr instr, int offset) {
ASSERT(IsLdrRegisterImmediate(instr));
bool positive = offset >= 0;
if (!positive) offset = -offset;
ASSERT(is_uint12(offset));
// Set bit indicating whether the offset should be added.
instr = (instr & ~B23) | (positive ? B23 : 0);
// Set the actual offset.
return (instr & ~kOff12Mask) | offset;
}
bool Assembler::IsStrRegisterImmediate(Instr instr) {
return (instr & (B27 | B26 | B25 | B22 | B20)) == B26;
}
Instr Assembler::SetStrRegisterImmediateOffset(Instr instr, int offset) {
ASSERT(IsStrRegisterImmediate(instr));
bool positive = offset >= 0;
if (!positive) offset = -offset;
ASSERT(is_uint12(offset));
// Set bit indicating whether the offset should be added.
instr = (instr & ~B23) | (positive ? B23 : 0);
// Set the actual offset.
return (instr & ~kOff12Mask) | offset;
}
bool Assembler::IsAddRegisterImmediate(Instr instr) {
return (instr & (B27 | B26 | B25 | B24 | B23 | B22 | B21)) == (B25 | B23);
}
Instr Assembler::SetAddRegisterImmediateOffset(Instr instr, int offset) {
ASSERT(IsAddRegisterImmediate(instr));
ASSERT(offset >= 0);
ASSERT(is_uint12(offset));
// Set the offset.
return (instr & ~kOff12Mask) | offset;
}
Register Assembler::GetRd(Instr instr) {
Register reg;
reg.code_ = Instruction::RdValue(instr);
return reg;
}
Register Assembler::GetRn(Instr instr) {
Register reg;
reg.code_ = Instruction::RnValue(instr);
return reg;
}
Register Assembler::GetRm(Instr instr) {
Register reg;
reg.code_ = Instruction::RmValue(instr);
return reg;
}
bool Assembler::IsPush(Instr instr) {
return ((instr & ~kRdMask) == kPushRegPattern);
}
bool Assembler::IsPop(Instr instr) {
return ((instr & ~kRdMask) == kPopRegPattern);
}
bool Assembler::IsStrRegFpOffset(Instr instr) {
return ((instr & kLdrStrInstrTypeMask) == kStrRegFpOffsetPattern);
}
bool Assembler::IsLdrRegFpOffset(Instr instr) {
return ((instr & kLdrStrInstrTypeMask) == kLdrRegFpOffsetPattern);
}
bool Assembler::IsStrRegFpNegOffset(Instr instr) {
return ((instr & kLdrStrInstrTypeMask) == kStrRegFpNegOffsetPattern);
}
bool Assembler::IsLdrRegFpNegOffset(Instr instr) {
return ((instr & kLdrStrInstrTypeMask) == kLdrRegFpNegOffsetPattern);
}
bool Assembler::IsLdrPcImmediateOffset(Instr instr) {
// Check the instruction is indeed a
// ldr<cond> <Rd>, [pc +/- offset_12].
return (instr & (kLdrPCMask & ~kCondMask)) == 0x051f0000;
}
bool Assembler::IsTstImmediate(Instr instr) {
return (instr & (B27 | B26 | I | kOpCodeMask | S | kRdMask)) ==
(I | TST | S);
}
bool Assembler::IsCmpRegister(Instr instr) {
return (instr & (B27 | B26 | I | kOpCodeMask | S | kRdMask | B4)) ==
(CMP | S);
}
bool Assembler::IsCmpImmediate(Instr instr) {
return (instr & (B27 | B26 | I | kOpCodeMask | S | kRdMask)) ==
(I | CMP | S);
}
Register Assembler::GetCmpImmediateRegister(Instr instr) {
ASSERT(IsCmpImmediate(instr));
return GetRn(instr);
}
int Assembler::GetCmpImmediateRawImmediate(Instr instr) {
ASSERT(IsCmpImmediate(instr));
return instr & kOff12Mask;
}
// Labels refer to positions in the (to be) generated code.
// There are bound, linked, and unused labels.
//
// Bound labels refer to known positions in the already
// generated code. pos() is the position the label refers to.
//
// Linked labels refer to unknown positions in the code
// to be generated; pos() is the position of the last
// instruction using the label.
// The link chain is terminated by a negative code position (must be aligned)
const int kEndOfChain = -4;
int Assembler::target_at(int pos) {
Instr instr = instr_at(pos);
if ((instr & ~kImm24Mask) == 0) {
// Emitted label constant, not part of a branch.
return instr - (Code::kHeaderSize - kHeapObjectTag);
}
ASSERT((instr & 7*B25) == 5*B25); // b, bl, or blx imm24
int imm26 = ((instr & kImm24Mask) << 8) >> 6;
if ((Instruction::ConditionField(instr) == kSpecialCondition) &&
((instr & B24) != 0)) {
// blx uses bit 24 to encode bit 2 of imm26
imm26 += 2;
}
return pos + kPcLoadDelta + imm26;
}
void Assembler::target_at_put(int pos, int target_pos) {
Instr instr = instr_at(pos);
if ((instr & ~kImm24Mask) == 0) {
ASSERT(target_pos == kEndOfChain || target_pos >= 0);
// Emitted label constant, not part of a branch.
// Make label relative to Code* of generated Code object.
instr_at_put(pos, target_pos + (Code::kHeaderSize - kHeapObjectTag));
return;
}
int imm26 = target_pos - (pos + kPcLoadDelta);
ASSERT((instr & 7*B25) == 5*B25); // b, bl, or blx imm24
if (Instruction::ConditionField(instr) == kSpecialCondition) {
// blx uses bit 24 to encode bit 2 of imm26
ASSERT((imm26 & 1) == 0);
instr = (instr & ~(B24 | kImm24Mask)) | ((imm26 & 2) >> 1)*B24;
} else {
ASSERT((imm26 & 3) == 0);
instr &= ~kImm24Mask;
}
int imm24 = imm26 >> 2;
ASSERT(is_int24(imm24));
instr_at_put(pos, instr | (imm24 & kImm24Mask));
}
void Assembler::print(Label* L) {
if (L->is_unused()) {
PrintF("unused label\n");
} else if (L->is_bound()) {
PrintF("bound label to %d\n", L->pos());
} else if (L->is_linked()) {
Label l = *L;
PrintF("unbound label");
while (l.is_linked()) {
PrintF("@ %d ", l.pos());
Instr instr = instr_at(l.pos());
if ((instr & ~kImm24Mask) == 0) {
PrintF("value\n");
} else {
ASSERT((instr & 7*B25) == 5*B25); // b, bl, or blx
Condition cond = Instruction::ConditionField(instr);
const char* b;
const char* c;
if (cond == kSpecialCondition) {
b = "blx";
c = "";
} else {
if ((instr & B24) != 0)
b = "bl";
else
b = "b";
switch (cond) {
case eq: c = "eq"; break;
case ne: c = "ne"; break;
case hs: c = "hs"; break;
case lo: c = "lo"; break;
case mi: c = "mi"; break;
case pl: c = "pl"; break;
case vs: c = "vs"; break;
case vc: c = "vc"; break;
case hi: c = "hi"; break;
case ls: c = "ls"; break;
case ge: c = "ge"; break;
case lt: c = "lt"; break;
case gt: c = "gt"; break;
case le: c = "le"; break;
case al: c = ""; break;
default:
c = "";
UNREACHABLE();
}
}
PrintF("%s%s\n", b, c);
}
next(&l);
}
} else {
PrintF("label in inconsistent state (pos = %d)\n", L->pos_);
}
}
void Assembler::bind_to(Label* L, int pos) {
ASSERT(0 <= pos && pos <= pc_offset()); // must have a valid binding position
while (L->is_linked()) {
int fixup_pos = L->pos();
next(L); // call next before overwriting link with target at fixup_pos
target_at_put(fixup_pos, pos);
}
L->bind_to(pos);
// Keep track of the last bound label so we don't eliminate any instructions
// before a bound label.
if (pos > last_bound_pos_)
last_bound_pos_ = pos;
}
void Assembler::link_to(Label* L, Label* appendix) {
if (appendix->is_linked()) {
if (L->is_linked()) {
// Append appendix to L's list.
int fixup_pos;
int link = L->pos();
do {
fixup_pos = link;
link = target_at(fixup_pos);
} while (link > 0);
ASSERT(link == kEndOfChain);
target_at_put(fixup_pos, appendix->pos());
} else {
// L is empty, simply use appendix.
*L = *appendix;
}
}
appendix->Unuse(); // appendix should not be used anymore
}
void Assembler::bind(Label* L) {
ASSERT(!L->is_bound()); // label can only be bound once
bind_to(L, pc_offset());
}
void Assembler::next(Label* L) {
ASSERT(L->is_linked());
int link = target_at(L->pos());
if (link > 0) {
L->link_to(link);
} else {
ASSERT(link == kEndOfChain);
L->Unuse();
}
}
static Instr EncodeMovwImmediate(uint32_t immediate) {
ASSERT(immediate < 0x10000);
return ((immediate & 0xf000) << 4) | (immediate & 0xfff);
}
// Low-level code emission routines depending on the addressing mode.
// If this returns true then you have to use the rotate_imm and immed_8
// that it returns, because it may have already changed the instruction
// to match them!
static bool fits_shifter(uint32_t imm32,
uint32_t* rotate_imm,
uint32_t* immed_8,
Instr* instr) {
// imm32 must be unsigned.
for (int rot = 0; rot < 16; rot++) {
uint32_t imm8 = (imm32 << 2*rot) | (imm32 >> (32 - 2*rot));
if ((imm8 <= 0xff)) {
*rotate_imm = rot;
*immed_8 = imm8;
return true;
}
}
// If the opcode is one with a complementary version and the complementary
// immediate fits, change the opcode.
if (instr != NULL) {
if ((*instr & kMovMvnMask) == kMovMvnPattern) {
if (fits_shifter(~imm32, rotate_imm, immed_8, NULL)) {
*instr ^= kMovMvnFlip;
return true;
} else if ((*instr & kMovLeaveCCMask) == kMovLeaveCCPattern) {
if (CpuFeatures::IsSupported(ARMv7)) {
if (imm32 < 0x10000) {
*instr ^= kMovwLeaveCCFlip;
*instr |= EncodeMovwImmediate(imm32);
*rotate_imm = *immed_8 = 0; // Not used for movw.
return true;
}
}
}
} else if ((*instr & kCmpCmnMask) == kCmpCmnPattern) {
if (fits_shifter(-imm32, rotate_imm, immed_8, NULL)) {
*instr ^= kCmpCmnFlip;
return true;
}
} else {
Instr alu_insn = (*instr & kALUMask);
if (alu_insn == ADD ||
alu_insn == SUB) {
if (fits_shifter(-imm32, rotate_imm, immed_8, NULL)) {
*instr ^= kAddSubFlip;
return true;
}
} else if (alu_insn == AND ||
alu_insn == BIC) {
if (fits_shifter(~imm32, rotate_imm, immed_8, NULL)) {
*instr ^= kAndBicFlip;
return true;
}
}
}
}
return false;
}
// We have to use the temporary register for things that can be relocated even
// if they can be encoded in the ARM's 12 bits of immediate-offset instruction
// space. There is no guarantee that the relocated location can be similarly
// encoded.
bool Operand::must_use_constant_pool() const {
if (rmode_ == RelocInfo::EXTERNAL_REFERENCE) {
#ifdef DEBUG
if (!Serializer::enabled()) {
Serializer::TooLateToEnableNow();
}
#endif // def DEBUG
return Serializer::enabled();
} else if (rmode_ == RelocInfo::NONE) {
return false;
}
return true;
}
bool Operand::is_single_instruction() const {
if (rm_.is_valid()) return true;
if (must_use_constant_pool()) return false;
uint32_t dummy1, dummy2;
return fits_shifter(imm32_, &dummy1, &dummy2, NULL);
}
void Assembler::addrmod1(Instr instr,
Register rn,
Register rd,
const Operand& x) {
CheckBuffer();
ASSERT((instr & ~(kCondMask | kOpCodeMask | S)) == 0);
if (!x.rm_.is_valid()) {
// Immediate.
uint32_t rotate_imm;
uint32_t immed_8;
if (x.must_use_constant_pool() ||
!fits_shifter(x.imm32_, &rotate_imm, &immed_8, &instr)) {
// The immediate operand cannot be encoded as a shifter operand, so load
// it first to register ip and change the original instruction to use ip.
// However, if the original instruction is a 'mov rd, x' (not setting the
// condition code), then replace it with a 'ldr rd, [pc]'.
CHECK(!rn.is(ip)); // rn should never be ip, or will be trashed
Condition cond = Instruction::ConditionField(instr);
if ((instr & ~kCondMask) == 13*B21) { // mov, S not set
if (x.must_use_constant_pool() || !CpuFeatures::IsSupported(ARMv7)) {
RecordRelocInfo(x.rmode_, x.imm32_);
ldr(rd, MemOperand(pc, 0), cond);
} else {
// Will probably use movw, will certainly not use constant pool.
mov(rd, Operand(x.imm32_ & 0xffff), LeaveCC, cond);
movt(rd, static_cast<uint32_t>(x.imm32_) >> 16, cond);
}
} else {
// If this is not a mov or mvn instruction we may still be able to avoid
// a constant pool entry by using mvn or movw.
if (!x.must_use_constant_pool() &&
(instr & kMovMvnMask) != kMovMvnPattern) {
mov(ip, x, LeaveCC, cond);
} else {
RecordRelocInfo(x.rmode_, x.imm32_);
ldr(ip, MemOperand(pc, 0), cond);
}
addrmod1(instr, rn, rd, Operand(ip));
}
return;
}
instr |= I | rotate_imm*B8 | immed_8;
} else if (!x.rs_.is_valid()) {
// Immediate shift.
instr |= x.shift_imm_*B7 | x.shift_op_ | x.rm_.code();
} else {
// Register shift.
ASSERT(!rn.is(pc) && !rd.is(pc) && !x.rm_.is(pc) && !x.rs_.is(pc));
instr |= x.rs_.code()*B8 | x.shift_op_ | B4 | x.rm_.code();
}
emit(instr | rn.code()*B16 | rd.code()*B12);
if (rn.is(pc) || x.rm_.is(pc)) {
// Block constant pool emission for one instruction after reading pc.
BlockConstPoolBefore(pc_offset() + kInstrSize);
}
}
void Assembler::addrmod2(Instr instr, Register rd, const MemOperand& x) {
ASSERT((instr & ~(kCondMask | B | L)) == B26);
int am = x.am_;
if (!x.rm_.is_valid()) {
// Immediate offset.
int offset_12 = x.offset_;
if (offset_12 < 0) {
offset_12 = -offset_12;
am ^= U;
}
if (!is_uint12(offset_12)) {
// Immediate offset cannot be encoded, load it first to register ip
// rn (and rd in a load) should never be ip, or will be trashed.
ASSERT(!x.rn_.is(ip) && ((instr & L) == L || !rd.is(ip)));
mov(ip, Operand(x.offset_), LeaveCC, Instruction::ConditionField(instr));
addrmod2(instr, rd, MemOperand(x.rn_, ip, x.am_));
return;
}
ASSERT(offset_12 >= 0); // no masking needed
instr |= offset_12;
} else {
// Register offset (shift_imm_ and shift_op_ are 0) or scaled
// register offset the constructors make sure than both shift_imm_
// and shift_op_ are initialized.
ASSERT(!x.rm_.is(pc));
instr |= B25 | x.shift_imm_*B7 | x.shift_op_ | x.rm_.code();
}
ASSERT((am & (P|W)) == P || !x.rn_.is(pc)); // no pc base with writeback
emit(instr | am | x.rn_.code()*B16 | rd.code()*B12);
}
void Assembler::addrmod3(Instr instr, Register rd, const MemOperand& x) {
ASSERT((instr & ~(kCondMask | L | S6 | H)) == (B4 | B7));
ASSERT(x.rn_.is_valid());
int am = x.am_;
if (!x.rm_.is_valid()) {
// Immediate offset.
int offset_8 = x.offset_;
if (offset_8 < 0) {
offset_8 = -offset_8;
am ^= U;
}
if (!is_uint8(offset_8)) {
// Immediate offset cannot be encoded, load it first to register ip
// rn (and rd in a load) should never be ip, or will be trashed.
ASSERT(!x.rn_.is(ip) && ((instr & L) == L || !rd.is(ip)));
mov(ip, Operand(x.offset_), LeaveCC, Instruction::ConditionField(instr));
addrmod3(instr, rd, MemOperand(x.rn_, ip, x.am_));
return;
}
ASSERT(offset_8 >= 0); // no masking needed
instr |= B | (offset_8 >> 4)*B8 | (offset_8 & 0xf);
} else if (x.shift_imm_ != 0) {
// Scaled register offset not supported, load index first
// rn (and rd in a load) should never be ip, or will be trashed.
ASSERT(!x.rn_.is(ip) && ((instr & L) == L || !rd.is(ip)));
mov(ip, Operand(x.rm_, x.shift_op_, x.shift_imm_), LeaveCC,
Instruction::ConditionField(instr));
addrmod3(instr, rd, MemOperand(x.rn_, ip, x.am_));
return;
} else {
// Register offset.
ASSERT((am & (P|W)) == P || !x.rm_.is(pc)); // no pc index with writeback
instr |= x.rm_.code();
}
ASSERT((am & (P|W)) == P || !x.rn_.is(pc)); // no pc base with writeback
emit(instr | am | x.rn_.code()*B16 | rd.code()*B12);
}
void Assembler::addrmod4(Instr instr, Register rn, RegList rl) {
ASSERT((instr & ~(kCondMask | P | U | W | L)) == B27);
ASSERT(rl != 0);
ASSERT(!rn.is(pc));
emit(instr | rn.code()*B16 | rl);
}
void Assembler::addrmod5(Instr instr, CRegister crd, const MemOperand& x) {
// Unindexed addressing is not encoded by this function.
ASSERT_EQ((B27 | B26),
(instr & ~(kCondMask | kCoprocessorMask | P | U | N | W | L)));
ASSERT(x.rn_.is_valid() && !x.rm_.is_valid());
int am = x.am_;
int offset_8 = x.offset_;
ASSERT((offset_8 & 3) == 0); // offset must be an aligned word offset
offset_8 >>= 2;
if (offset_8 < 0) {
offset_8 = -offset_8;
am ^= U;
}
ASSERT(is_uint8(offset_8)); // unsigned word offset must fit in a byte
ASSERT((am & (P|W)) == P || !x.rn_.is(pc)); // no pc base with writeback
// Post-indexed addressing requires W == 1; different than in addrmod2/3.
if ((am & P) == 0)
am |= W;
ASSERT(offset_8 >= 0); // no masking needed
emit(instr | am | x.rn_.code()*B16 | crd.code()*B12 | offset_8);
}
int Assembler::branch_offset(Label* L, bool jump_elimination_allowed) {
int target_pos;
if (L->is_bound()) {
target_pos = L->pos();
} else {
if (L->is_linked()) {
target_pos = L->pos(); // L's link
} else {
target_pos = kEndOfChain;
}
L->link_to(pc_offset());
}
// Block the emission of the constant pool, since the branch instruction must
// be emitted at the pc offset recorded by the label.
BlockConstPoolBefore(pc_offset() + kInstrSize);
return target_pos - (pc_offset() + kPcLoadDelta);
}
void Assembler::label_at_put(Label* L, int at_offset) {
int target_pos;
if (L->is_bound()) {
target_pos = L->pos();
} else {
if (L->is_linked()) {
target_pos = L->pos(); // L's link
} else {
target_pos = kEndOfChain;
}
L->link_to(at_offset);
instr_at_put(at_offset, target_pos + (Code::kHeaderSize - kHeapObjectTag));
}
}
// Branch instructions.
void Assembler::b(int branch_offset, Condition cond) {
ASSERT((branch_offset & 3) == 0);
int imm24 = branch_offset >> 2;
ASSERT(is_int24(imm24));
emit(cond | B27 | B25 | (imm24 & kImm24Mask));
if (cond == al) {
// Dead code is a good location to emit the constant pool.
CheckConstPool(false, false);
}
}
void Assembler::bl(int branch_offset, Condition cond) {
positions_recorder()->WriteRecordedPositions();
ASSERT((branch_offset & 3) == 0);
int imm24 = branch_offset >> 2;
ASSERT(is_int24(imm24));
emit(cond | B27 | B25 | B24 | (imm24 & kImm24Mask));
}
void Assembler::blx(int branch_offset) { // v5 and above
positions_recorder()->WriteRecordedPositions();
ASSERT((branch_offset & 1) == 0);
int h = ((branch_offset & 2) >> 1)*B24;
int imm24 = branch_offset >> 2;
ASSERT(is_int24(imm24));
emit(kSpecialCondition | B27 | B25 | h | (imm24 & kImm24Mask));
}
void Assembler::blx(Register target, Condition cond) { // v5 and above
positions_recorder()->WriteRecordedPositions();
ASSERT(!target.is(pc));
emit(cond | B24 | B21 | 15*B16 | 15*B12 | 15*B8 | BLX | target.code());
}
void Assembler::bx(Register target, Condition cond) { // v5 and above, plus v4t
positions_recorder()->WriteRecordedPositions();
ASSERT(!target.is(pc)); // use of pc is actually allowed, but discouraged
emit(cond | B24 | B21 | 15*B16 | 15*B12 | 15*B8 | BX | target.code());
}
// Data-processing instructions.
void Assembler::and_(Register dst, Register src1, const Operand& src2,
SBit s, Condition cond) {
addrmod1(cond | AND | s, src1, dst, src2);
}
void Assembler::eor(Register dst, Register src1, const Operand& src2,
SBit s, Condition cond) {
addrmod1(cond | EOR | s, src1, dst, src2);
}
void Assembler::sub(Register dst, Register src1, const Operand& src2,
SBit s, Condition cond) {
addrmod1(cond | SUB | s, src1, dst, src2);
}
void Assembler::rsb(Register dst, Register src1, const Operand& src2,
SBit s, Condition cond) {
addrmod1(cond | RSB | s, src1, dst, src2);
}
void Assembler::add(Register dst, Register src1, const Operand& src2,
SBit s, Condition cond) {
addrmod1(cond | ADD | s, src1, dst, src2);
// Eliminate pattern: push(r), pop()
// str(src, MemOperand(sp, 4, NegPreIndex), al);
// add(sp, sp, Operand(kPointerSize));
// Both instructions can be eliminated.
if (can_peephole_optimize(2) &&
// Pattern.
instr_at(pc_ - 1 * kInstrSize) == kPopInstruction &&
(instr_at(pc_ - 2 * kInstrSize) & ~kRdMask) == kPushRegPattern) {
pc_ -= 2 * kInstrSize;
if (FLAG_print_peephole_optimization) {
PrintF("%x push(reg)/pop() eliminated\n", pc_offset());
}
}
}
void Assembler::adc(Register dst, Register src1, const Operand& src2,
SBit s, Condition cond) {
addrmod1(cond | ADC | s, src1, dst, src2);
}
void Assembler::sbc(Register dst, Register src1, const Operand& src2,
SBit s, Condition cond) {
addrmod1(cond | SBC | s, src1, dst, src2);
}
void Assembler::rsc(Register dst, Register src1, const Operand& src2,
SBit s, Condition cond) {
addrmod1(cond | RSC | s, src1, dst, src2);
}
void Assembler::tst(Register src1, const Operand& src2, Condition cond) {
addrmod1(cond | TST | S, src1, r0, src2);
}
void Assembler::teq(Register src1, const Operand& src2, Condition cond) {
addrmod1(cond | TEQ | S, src1, r0, src2);
}
void Assembler::cmp(Register src1, const Operand& src2, Condition cond) {
addrmod1(cond | CMP | S, src1, r0, src2);
}
void Assembler::cmp_raw_immediate(
Register src, int raw_immediate, Condition cond) {
ASSERT(is_uint12(raw_immediate));
emit(cond | I | CMP | S | src.code() << 16 | raw_immediate);
}
void Assembler::cmn(Register src1, const Operand& src2, Condition cond) {
addrmod1(cond | CMN | S, src1, r0, src2);
}
void Assembler::orr(Register dst, Register src1, const Operand& src2,
SBit s, Condition cond) {
addrmod1(cond | ORR | s, src1, dst, src2);
}
void Assembler::mov(Register dst, const Operand& src, SBit s, Condition cond) {
if (dst.is(pc)) {
positions_recorder()->WriteRecordedPositions();
}
// Don't allow nop instructions in the form mov rn, rn to be generated using
// the mov instruction. They must be generated using nop(int/NopMarkerTypes)
// or MarkCode(int/NopMarkerTypes) pseudo instructions.
ASSERT(!(src.is_reg() && src.rm().is(dst) && s == LeaveCC && cond == al));
addrmod1(cond | MOV | s, r0, dst, src);
}
void Assembler::movw(Register reg, uint32_t immediate, Condition cond) {
ASSERT(immediate < 0x10000);
mov(reg, Operand(immediate), LeaveCC, cond);
}
void Assembler::movt(Register reg, uint32_t immediate, Condition cond) {
emit(cond | 0x34*B20 | reg.code()*B12 | EncodeMovwImmediate(immediate));
}
void Assembler::bic(Register dst, Register src1, const Operand& src2,
SBit s, Condition cond) {
addrmod1(cond | BIC | s, src1, dst, src2);
}
void Assembler::mvn(Register dst, const Operand& src, SBit s, Condition cond) {
addrmod1(cond | MVN | s, r0, dst, src);
}
// Multiply instructions.
void Assembler::mla(Register dst, Register src1, Register src2, Register srcA,
SBit s, Condition cond) {
ASSERT(!dst.is(pc) && !src1.is(pc) && !src2.is(pc) && !srcA.is(pc));
emit(cond | A | s | dst.code()*B16 | srcA.code()*B12 |
src2.code()*B8 | B7 | B4 | src1.code());
}
void Assembler::mul(Register dst, Register src1, Register src2,
SBit s, Condition cond) {
ASSERT(!dst.is(pc) && !src1.is(pc) && !src2.is(pc));
// dst goes in bits 16-19 for this instruction!
emit(cond | s | dst.code()*B16 | src2.code()*B8 | B7 | B4 | src1.code());
}
void Assembler::smlal(Register dstL,
Register dstH,
Register src1,
Register src2,
SBit s,
Condition cond) {
ASSERT(!dstL.is(pc) && !dstH.is(pc) && !src1.is(pc) && !src2.is(pc));
ASSERT(!dstL.is(dstH));
emit(cond | B23 | B22 | A | s | dstH.code()*B16 | dstL.code()*B12 |
src2.code()*B8 | B7 | B4 | src1.code());
}
void Assembler::smull(Register dstL,
Register dstH,
Register src1,
Register src2,
SBit s,
Condition cond) {
ASSERT(!dstL.is(pc) && !dstH.is(pc) && !src1.is(pc) && !src2.is(pc));
ASSERT(!dstL.is(dstH));
emit(cond | B23 | B22 | s | dstH.code()*B16 | dstL.code()*B12 |
src2.code()*B8 | B7 | B4 | src1.code());
}
void Assembler::umlal(Register dstL,
Register dstH,
Register src1,
Register src2,
SBit s,
Condition cond) {
ASSERT(!dstL.is(pc) && !dstH.is(pc) && !src1.is(pc) && !src2.is(pc));
ASSERT(!dstL.is(dstH));
emit(cond | B23 | A | s | dstH.code()*B16 | dstL.code()*B12 |
src2.code()*B8 | B7 | B4 | src1.code());
}
void Assembler::umull(Register dstL,
Register dstH,
Register src1,
Register src2,
SBit s,
Condition cond) {
ASSERT(!dstL.is(pc) && !dstH.is(pc) && !src1.is(pc) && !src2.is(pc));
ASSERT(!dstL.is(dstH));
emit(cond | B23 | s | dstH.code()*B16 | dstL.code()*B12 |
src2.code()*B8 | B7 | B4 | src1.code());
}
// Miscellaneous arithmetic instructions.
void Assembler::clz(Register dst, Register src, Condition cond) {
// v5 and above.
ASSERT(!dst.is(pc) && !src.is(pc));
emit(cond | B24 | B22 | B21 | 15*B16 | dst.code()*B12 |
15*B8 | CLZ | src.code());
}
// Saturating instructions.
// Unsigned saturate.
void Assembler::usat(Register dst,
int satpos,
const Operand& src,
Condition cond) {
// v6 and above.
ASSERT(CpuFeatures::IsSupported(ARMv7));
ASSERT(!dst.is(pc) && !src.rm_.is(pc));
ASSERT((satpos >= 0) && (satpos <= 31));
ASSERT((src.shift_op_ == ASR) || (src.shift_op_ == LSL));
ASSERT(src.rs_.is(no_reg));
int sh = 0;
if (src.shift_op_ == ASR) {
sh = 1;
}
emit(cond | 0x6*B24 | 0xe*B20 | satpos*B16 | dst.code()*B12 |
src.shift_imm_*B7 | sh*B6 | 0x1*B4 | src.rm_.code());
}
// Bitfield manipulation instructions.
// Unsigned bit field extract.
// Extracts #width adjacent bits from position #lsb in a register, and
// writes them to the low bits of a destination register.
// ubfx dst, src, #lsb, #width
void Assembler::ubfx(Register dst,
Register src,
int lsb,
int width,
Condition cond) {
// v7 and above.
ASSERT(CpuFeatures::IsSupported(ARMv7));
ASSERT(!dst.is(pc) && !src.is(pc));
ASSERT((lsb >= 0) && (lsb <= 31));
ASSERT((width >= 1) && (width <= (32 - lsb)));
emit(cond | 0xf*B23 | B22 | B21 | (width - 1)*B16 | dst.code()*B12 |
lsb*B7 | B6 | B4 | src.code());
}
// Signed bit field extract.
// Extracts #width adjacent bits from position #lsb in a register, and
// writes them to the low bits of a destination register. The extracted
// value is sign extended to fill the destination register.
// sbfx dst, src, #lsb, #width
void Assembler::sbfx(Register dst,
Register src,
int lsb,
int width,
Condition cond) {
// v7 and above.
ASSERT(CpuFeatures::IsSupported(ARMv7));
ASSERT(!dst.is(pc) && !src.is(pc));
ASSERT((lsb >= 0) && (lsb <= 31));
ASSERT((width >= 1) && (width <= (32 - lsb)));
emit(cond | 0xf*B23 | B21 | (width - 1)*B16 | dst.code()*B12 |
lsb*B7 | B6 | B4 | src.code());
}
// Bit field clear.
// Sets #width adjacent bits at position #lsb in the destination register
// to zero, preserving the value of the other bits.
// bfc dst, #lsb, #width
void Assembler::bfc(Register dst, int lsb, int width, Condition cond) {
// v7 and above.
ASSERT(CpuFeatures::IsSupported(ARMv7));
ASSERT(!dst.is(pc));
ASSERT((lsb >= 0) && (lsb <= 31));
ASSERT((width >= 1) && (width <= (32 - lsb)));
int msb = lsb + width - 1;
emit(cond | 0x1f*B22 | msb*B16 | dst.code()*B12 | lsb*B7 | B4 | 0xf);
}
// Bit field insert.
// Inserts #width adjacent bits from the low bits of the source register
// into position #lsb of the destination register.
// bfi dst, src, #lsb, #width
void Assembler::bfi(Register dst,
Register src,
int lsb,
int width,
Condition cond) {
// v7 and above.
ASSERT(CpuFeatures::IsSupported(ARMv7));
ASSERT(!dst.is(pc) && !src.is(pc));
ASSERT((lsb >= 0) && (lsb <= 31));
ASSERT((width >= 1) && (width <= (32 - lsb)));
int msb = lsb + width - 1;
emit(cond | 0x1f*B22 | msb*B16 | dst.code()*B12 | lsb*B7 | B4 |
src.code());
}
// Status register access instructions.
void Assembler::mrs(Register dst, SRegister s, Condition cond) {
ASSERT(!dst.is(pc));
emit(cond | B24 | s | 15*B16 | dst.code()*B12);
}
void Assembler::msr(SRegisterFieldMask fields, const Operand& src,
Condition cond) {
ASSERT(fields >= B16 && fields < B20); // at least one field set
Instr instr;
if (!src.rm_.is_valid()) {
// Immediate.
uint32_t rotate_imm;
uint32_t immed_8;
if (src.must_use_constant_pool() ||
!fits_shifter(src.imm32_, &rotate_imm, &immed_8, NULL)) {
// Immediate operand cannot be encoded, load it first to register ip.
RecordRelocInfo(src.rmode_, src.imm32_);
ldr(ip, MemOperand(pc, 0), cond);
msr(fields, Operand(ip), cond);
return;
}
instr = I | rotate_imm*B8 | immed_8;
} else {
ASSERT(!src.rs_.is_valid() && src.shift_imm_ == 0); // only rm allowed
instr = src.rm_.code();
}
emit(cond | instr | B24 | B21 | fields | 15*B12);
}
// Load/Store instructions.
void Assembler::ldr(Register dst, const MemOperand& src, Condition cond) {
if (dst.is(pc)) {
positions_recorder()->WriteRecordedPositions();
}
addrmod2(cond | B26 | L, dst, src);
// Eliminate pattern: push(ry), pop(rx)
// str(ry, MemOperand(sp, 4, NegPreIndex), al)
// ldr(rx, MemOperand(sp, 4, PostIndex), al)
// Both instructions can be eliminated if ry = rx.
// If ry != rx, a register copy from ry to rx is inserted
// after eliminating the push and the pop instructions.
if (can_peephole_optimize(2)) {
Instr push_instr = instr_at(pc_ - 2 * kInstrSize);
Instr pop_instr = instr_at(pc_ - 1 * kInstrSize);
if (IsPush(push_instr) && IsPop(pop_instr)) {
if (Instruction::RdValue(pop_instr) != Instruction::RdValue(push_instr)) {
// For consecutive push and pop on different registers,
// we delete both the push & pop and insert a register move.
// push ry, pop rx --> mov rx, ry
Register reg_pushed, reg_popped;
reg_pushed = GetRd(push_instr);
reg_popped = GetRd(pop_instr);
pc_ -= 2 * kInstrSize;
// Insert a mov instruction, which is better than a pair of push & pop
mov(reg_popped, reg_pushed);
if (FLAG_print_peephole_optimization) {
PrintF("%x push/pop (diff reg) replaced by a reg move\n",
pc_offset());
}
} else {
// For consecutive push and pop on the same register,
// both the push and the pop can be deleted.
pc_ -= 2 * kInstrSize;
if (FLAG_print_peephole_optimization) {
PrintF("%x push/pop (same reg) eliminated\n", pc_offset());
}
}
}
}
if (can_peephole_optimize(2)) {
Instr str_instr = instr_at(pc_ - 2 * kInstrSize);
Instr ldr_instr = instr_at(pc_ - 1 * kInstrSize);
if ((IsStrRegFpOffset(str_instr) &&
IsLdrRegFpOffset(ldr_instr)) ||
(IsStrRegFpNegOffset(str_instr) &&
IsLdrRegFpNegOffset(ldr_instr))) {
if ((ldr_instr & kLdrStrInstrArgumentMask) ==
(str_instr & kLdrStrInstrArgumentMask)) {
// Pattern: Ldr/str same fp+offset, same register.
//
// The following:
// str rx, [fp, #-12]
// ldr rx, [fp, #-12]
//
// Becomes:
// str rx, [fp, #-12]
pc_ -= 1 * kInstrSize;
if (FLAG_print_peephole_optimization) {
PrintF("%x str/ldr (fp + same offset), same reg\n", pc_offset());
}
} else if ((ldr_instr & kLdrStrOffsetMask) ==
(str_instr & kLdrStrOffsetMask)) {
// Pattern: Ldr/str same fp+offset, different register.
//
// The following:
// str rx, [fp, #-12]
// ldr ry, [fp, #-12]
//
// Becomes:
// str rx, [fp, #-12]
// mov ry, rx
Register reg_stored, reg_loaded;
reg_stored = GetRd(str_instr);
reg_loaded = GetRd(ldr_instr);
pc_ -= 1 * kInstrSize;
// Insert a mov instruction, which is better than ldr.
mov(reg_loaded, reg_stored);
if (FLAG_print_peephole_optimization) {
PrintF("%x str/ldr (fp + same offset), diff reg \n", pc_offset());
}
}
}
}
if (can_peephole_optimize(3)) {
Instr mem_write_instr = instr_at(pc_ - 3 * kInstrSize);
Instr ldr_instr = instr_at(pc_ - 2 * kInstrSize);
Instr mem_read_instr = instr_at(pc_ - 1 * kInstrSize);
if (IsPush(mem_write_instr) &&
IsPop(mem_read_instr)) {
if ((IsLdrRegFpOffset(ldr_instr) ||
IsLdrRegFpNegOffset(ldr_instr))) {
if (Instruction::RdValue(mem_write_instr) ==
Instruction::RdValue(mem_read_instr)) {
// Pattern: push & pop from/to same register,
// with a fp+offset ldr in between
//
// The following:
// str rx, [sp, #-4]!
// ldr rz, [fp, #-24]
// ldr rx, [sp], #+4
//
// Becomes:
// if(rx == rz)
// delete all
// else
// ldr rz, [fp, #-24]
if (Instruction::RdValue(mem_write_instr) ==
Instruction::RdValue(ldr_instr)) {
pc_ -= 3 * kInstrSize;
} else {
pc_ -= 3 * kInstrSize;
// Reinsert back the ldr rz.
emit(ldr_instr);
}
if (FLAG_print_peephole_optimization) {
PrintF("%x push/pop -dead ldr fp+offset in middle\n", pc_offset());
}
} else {
// Pattern: push & pop from/to different registers
// with a fp+offset ldr in between
//
// The following:
// str rx, [sp, #-4]!
// ldr rz, [fp, #-24]
// ldr ry, [sp], #+4
//
// Becomes:
// if(ry == rz)
// mov ry, rx;
// else if(rx != rz)
// ldr rz, [fp, #-24]
// mov ry, rx
// else if((ry != rz) || (rx == rz)) becomes:
// mov ry, rx
// ldr rz, [fp, #-24]
Register reg_pushed, reg_popped;
if (Instruction::RdValue(mem_read_instr) ==
Instruction::RdValue(ldr_instr)) {
reg_pushed = GetRd(mem_write_instr);
reg_popped = GetRd(mem_read_instr);
pc_ -= 3 * kInstrSize;
mov(reg_popped, reg_pushed);
} else if (Instruction::RdValue(mem_write_instr) !=
Instruction::RdValue(ldr_instr)) {
reg_pushed = GetRd(mem_write_instr);
reg_popped = GetRd(mem_read_instr);
pc_ -= 3 * kInstrSize;
emit(ldr_instr);
mov(reg_popped, reg_pushed);
} else if ((Instruction::RdValue(mem_read_instr) !=
Instruction::RdValue(ldr_instr)) ||
(Instruction::RdValue(mem_write_instr) ==
Instruction::RdValue(ldr_instr))) {
reg_pushed = GetRd(mem_write_instr);
reg_popped = GetRd(mem_read_instr);
pc_ -= 3 * kInstrSize;
mov(reg_popped, reg_pushed);
emit(ldr_instr);
}
if (FLAG_print_peephole_optimization) {
PrintF("%x push/pop (ldr fp+off in middle)\n", pc_offset());
}
}
}
}
}
}
void Assembler::str(Register src, const MemOperand& dst, Condition cond) {
addrmod2(cond | B26, src, dst);
// Eliminate pattern: pop(), push(r)
// add sp, sp, #4 LeaveCC, al; str r, [sp, #-4], al
// -> str r, [sp, 0], al
if (can_peephole_optimize(2) &&
// Pattern.
instr_at(pc_ - 1 * kInstrSize) == (kPushRegPattern | src.code() * B12) &&
instr_at(pc_ - 2 * kInstrSize) == kPopInstruction) {
pc_ -= 2 * kInstrSize;
emit(al | B26 | 0 | Offset | sp.code() * B16 | src.code() * B12);
if (FLAG_print_peephole_optimization) {
PrintF("%x pop()/push(reg) eliminated\n", pc_offset());
}
}
}
void Assembler::ldrb(Register dst, const MemOperand& src, Condition cond) {
addrmod2(cond | B26 | B | L, dst, src);
}
void Assembler::strb(Register src, const MemOperand& dst, Condition cond) {
addrmod2(cond | B26 | B, src, dst);
}
void Assembler::ldrh(Register dst, const MemOperand& src, Condition cond) {
addrmod3(cond | L | B7 | H | B4, dst, src);
}
void Assembler::strh(Register src, const MemOperand& dst, Condition cond) {
addrmod3(cond | B7 | H | B4, src, dst);
}
void Assembler::ldrsb(Register dst, const MemOperand& src, Condition cond) {
addrmod3(cond | L | B7 | S6 | B4, dst, src);
}
void Assembler::ldrsh(Register dst, const MemOperand& src, Condition cond) {
addrmod3(cond | L | B7 | S6 | H | B4, dst, src);
}
void Assembler::ldrd(Register dst1, Register dst2,
const MemOperand& src, Condition cond) {
ASSERT(CpuFeatures::IsEnabled(ARMv7));
ASSERT(src.rm().is(no_reg));
ASSERT(!dst1.is(lr)); // r14.
ASSERT_EQ(0, dst1.code() % 2);
ASSERT_EQ(dst1.code() + 1, dst2.code());
addrmod3(cond | B7 | B6 | B4, dst1, src);
}
void Assembler::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());
ASSERT(CpuFeatures::IsEnabled(ARMv7));
addrmod3(cond | B7 | B6 | B5 | B4, src1, dst);
}
// Load/Store multiple instructions.
void Assembler::ldm(BlockAddrMode am,
Register base,
RegList dst,
Condition cond) {
// ABI stack constraint: ldmxx base, {..sp..} base != sp is not restartable.
ASSERT(base.is(sp) || (dst & sp.bit()) == 0);
addrmod4(cond | B27 | am | L, base, dst);
// Emit the constant pool after a function return implemented by ldm ..{..pc}.
if (cond == al && (dst & pc.bit()) != 0) {
// There is a slight chance that the ldm instruction was actually a call,
// in which case it would be wrong to return into the constant pool; we
// recognize this case by checking if the emission of the pool was blocked
// at the pc of the ldm instruction by a mov lr, pc instruction; if this is
// the case, we emit a jump over the pool.
CheckConstPool(true, no_const_pool_before_ == pc_offset() - kInstrSize);
}
}
void Assembler::stm(BlockAddrMode am,
Register base,
RegList src,
Condition cond) {
addrmod4(cond | B27 | am, base, src);
}
// Exception-generating instructions and debugging support.
// Stops with a non-negative code less than kNumOfWatchedStops support
// enabling/disabling and a counter feature. See simulator-arm.h .
void Assembler::stop(const char* msg, Condition cond, int32_t code) {
#ifndef __arm__
ASSERT(code >= kDefaultStopCode);
// The Simulator will handle the stop instruction and get the message address.
// It expects to find the address just after the svc instruction.
BlockConstPoolFor(2);
if (code >= 0) {
svc(kStopCode + code, cond);
} else {
svc(kStopCode + kMaxStopCode, cond);
}
emit(reinterpret_cast<Instr>(msg));
#else // def __arm__
#ifdef CAN_USE_ARMV5_INSTRUCTIONS
if (cond != al) {
Label skip;
b(&skip, NegateCondition(cond));
bkpt(0);
bind(&skip);
} else {
bkpt(0);
}
#else // ndef CAN_USE_ARMV5_INSTRUCTIONS
svc(0x9f0001, cond);
#endif // ndef CAN_USE_ARMV5_INSTRUCTIONS
#endif // def __arm__
}
void Assembler::bkpt(uint32_t imm16) { // v5 and above
ASSERT(is_uint16(imm16));
emit(al | B24 | B21 | (imm16 >> 4)*B8 | BKPT | (imm16 & 0xf));
}
void Assembler::svc(uint32_t imm24, Condition cond) {
ASSERT(is_uint24(imm24));
emit(cond | 15*B24 | imm24);
}
// Coprocessor instructions.
void Assembler::cdp(Coprocessor coproc,
int opcode_1,
CRegister crd,
CRegister crn,
CRegister crm,
int opcode_2,
Condition cond) {
ASSERT(is_uint4(opcode_1) && is_uint3(opcode_2));
emit(cond | B27 | B26 | B25 | (opcode_1 & 15)*B20 | crn.code()*B16 |
crd.code()*B12 | coproc*B8 | (opcode_2 & 7)*B5 | crm.code());
}
void Assembler::cdp2(Coprocessor coproc,
int opcode_1,
CRegister crd,
CRegister crn,
CRegister crm,
int opcode_2) { // v5 and above
cdp(coproc, opcode_1, crd, crn, crm, opcode_2, kSpecialCondition);
}
void Assembler::mcr(Coprocessor coproc,
int opcode_1,
Register rd,
CRegister crn,
CRegister crm,
int opcode_2,
Condition cond) {
ASSERT(is_uint3(opcode_1) && is_uint3(opcode_2));
emit(cond | B27 | B26 | B25 | (opcode_1 & 7)*B21 | crn.code()*B16 |
rd.code()*B12 | coproc*B8 | (opcode_2 & 7)*B5 | B4 | crm.code());
}
void Assembler::mcr2(Coprocessor coproc,
int opcode_1,
Register rd,
CRegister crn,
CRegister crm,
int opcode_2) { // v5 and above
mcr(coproc, opcode_1, rd, crn, crm, opcode_2, kSpecialCondition);
}
void Assembler::mrc(Coprocessor coproc,
int opcode_1,
Register rd,
CRegister crn,
CRegister crm,
int opcode_2,
Condition cond) {
ASSERT(is_uint3(opcode_1) && is_uint3(opcode_2));
emit(cond | B27 | B26 | B25 | (opcode_1 & 7)*B21 | L | crn.code()*B16 |
rd.code()*B12 | coproc*B8 | (opcode_2 & 7)*B5 | B4 | crm.code());
}
void Assembler::mrc2(Coprocessor coproc,
int opcode_1,
Register rd,
CRegister crn,
CRegister crm,
int opcode_2) { // v5 and above
mrc(coproc, opcode_1, rd, crn, crm, opcode_2, kSpecialCondition);
}
void Assembler::ldc(Coprocessor coproc,
CRegister crd,
const MemOperand& src,
LFlag l,
Condition cond) {
addrmod5(cond | B27 | B26 | l | L | coproc*B8, crd, src);
}
void Assembler::ldc(Coprocessor coproc,
CRegister crd,
Register rn,
int option,
LFlag l,
Condition cond) {
// Unindexed addressing.
ASSERT(is_uint8(option));
emit(cond | B27 | B26 | U | l | L | rn.code()*B16 | crd.code()*B12 |
coproc*B8 | (option & 255));
}
void Assembler::ldc2(Coprocessor coproc,
CRegister crd,
const MemOperand& src,
LFlag l) { // v5 and above
ldc(coproc, crd, src, l, kSpecialCondition);
}
void Assembler::ldc2(Coprocessor coproc,
CRegister crd,
Register rn,
int option,
LFlag l) { // v5 and above
ldc(coproc, crd, rn, option, l, kSpecialCondition);
}
void Assembler::stc(Coprocessor coproc,
CRegister crd,
const MemOperand& dst,
LFlag l,
Condition cond) {
addrmod5(cond | B27 | B26 | l | coproc*B8, crd, dst);
}
void Assembler::stc(Coprocessor coproc,
CRegister crd,
Register rn,
int option,
LFlag l,
Condition cond) {
// Unindexed addressing.
ASSERT(is_uint8(option));
emit(cond | B27 | B26 | U | l | rn.code()*B16 | crd.code()*B12 |
coproc*B8 | (option & 255));
}
void Assembler::stc2(Coprocessor
coproc, CRegister crd,
const MemOperand& dst,
LFlag l) { // v5 and above
stc(coproc, crd, dst, l, kSpecialCondition);
}
void Assembler::stc2(Coprocessor coproc,
CRegister crd,
Register rn,
int option,
LFlag l) { // v5 and above
stc(coproc, crd, rn, option, l, kSpecialCondition);
}
// Support for VFP.
void Assembler::vldr(const DwVfpRegister dst,
const Register base,
int offset,
const Condition cond) {
// Ddst = MEM(Rbase + offset).
// Instruction details available in ARM DDI 0406A, A8-628.
// cond(31-28) | 1101(27-24)| U001(23-20) | Rbase(19-16) |
// Vdst(15-12) | 1011(11-8) | offset
ASSERT(CpuFeatures::IsEnabled(VFP3));
int u = 1;
if (offset < 0) {
offset = -offset;
u = 0;
}
ASSERT(offset >= 0);
if ((offset % 4) == 0 && (offset / 4) < 256) {
emit(cond | u*B23 | 0xD1*B20 | base.code()*B16 | dst.code()*B12 |
0xB*B8 | ((offset / 4) & 255));
} else {
// Larger offsets must be handled by computing the correct address
// in the ip register.
ASSERT(!base.is(ip));
if (u == 1) {
add(ip, base, Operand(offset));
} else {
sub(ip, base, Operand(offset));
}
emit(cond | 0xD1*B20 | ip.code()*B16 | dst.code()*B12 | 0xB*B8);
}
}
void Assembler::vldr(const DwVfpRegister dst,
const MemOperand& operand,
const Condition cond) {
ASSERT(!operand.rm().is_valid());
ASSERT(operand.am_ == Offset);
vldr(dst, operand.rn(), operand.offset(), cond);
}
void Assembler::vldr(const SwVfpRegister dst,
const Register base,
int offset,
const Condition cond) {
// Sdst = MEM(Rbase + offset).
// Instruction details available in ARM DDI 0406A, A8-628.
// cond(31-28) | 1101(27-24)| U001(23-20) | Rbase(19-16) |
// Vdst(15-12) | 1010(11-8) | offset
ASSERT(CpuFeatures::IsEnabled(VFP3));
int u = 1;
if (offset < 0) {
offset = -offset;
u = 0;
}
int sd, d;
dst.split_code(&sd, &d);
ASSERT(offset >= 0);
if ((offset % 4) == 0 && (offset / 4) < 256) {
emit(cond | u*B23 | d*B22 | 0xD1*B20 | base.code()*B16 | sd*B12 |
0xA*B8 | ((offset / 4) & 255));
} else {
// Larger offsets must be handled by computing the correct address
// in the ip register.
ASSERT(!base.is(ip));
if (u == 1) {
add(ip, base, Operand(offset));
} else {
sub(ip, base, Operand(offset));
}
emit(cond | d*B22 | 0xD1*B20 | ip.code()*B16 | sd*B12 | 0xA*B8);
}
}
void Assembler::vldr(const SwVfpRegister dst,
const MemOperand& operand,
const Condition cond) {
ASSERT(!operand.rm().is_valid());
ASSERT(operand.am_ == Offset);
vldr(dst, operand.rn(), operand.offset(), cond);
}
void Assembler::vstr(const DwVfpRegister src,
const Register base,
int offset,
const Condition cond) {
// MEM(Rbase + offset) = Dsrc.
// Instruction details available in ARM DDI 0406A, A8-786.
// cond(31-28) | 1101(27-24)| U000(23-20) | | Rbase(19-16) |
// Vsrc(15-12) | 1011(11-8) | (offset/4)
ASSERT(CpuFeatures::IsEnabled(VFP3));
int u = 1;
if (offset < 0) {
offset = -offset;
u = 0;
}
ASSERT(offset >= 0);
if ((offset % 4) == 0 && (offset / 4) < 256) {
emit(cond | u*B23 | 0xD0*B20 | base.code()*B16 | src.code()*B12 |
0xB*B8 | ((offset / 4) & 255));
} else {
// Larger offsets must be handled by computing the correct address
// in the ip register.
ASSERT(!base.is(ip));
if (u == 1) {
add(ip, base, Operand(offset));
} else {
sub(ip, base, Operand(offset));
}
emit(cond | 0xD0*B20 | ip.code()*B16 | src.code()*B12 | 0xB*B8);
}
}
void Assembler::vstr(const DwVfpRegister src,
const MemOperand& operand,
const Condition cond) {
ASSERT(!operand.rm().is_valid());
ASSERT(operand.am_ == Offset);
vstr(src, operand.rn(), operand.offset(), cond);
}
void Assembler::vstr(const SwVfpRegister src,
const Register base,
int offset,
const Condition cond) {
// MEM(Rbase + offset) = SSrc.
// Instruction details available in ARM DDI 0406A, A8-786.
// cond(31-28) | 1101(27-24)| U000(23-20) | Rbase(19-16) |
// Vdst(15-12) | 1010(11-8) | (offset/4)
ASSERT(CpuFeatures::IsEnabled(VFP3));
int u = 1;
if (offset < 0) {
offset = -offset;
u = 0;
}
int sd, d;
src.split_code(&sd, &d);
ASSERT(offset >= 0);
if ((offset % 4) == 0 && (offset / 4) < 256) {
emit(cond | u*B23 | d*B22 | 0xD0*B20 | base.code()*B16 | sd*B12 |
0xA*B8 | ((offset / 4) & 255));
} else {
// Larger offsets must be handled by computing the correct address
// in the ip register.
ASSERT(!base.is(ip));
if (u == 1) {
add(ip, base, Operand(offset));
} else {
sub(ip, base, Operand(offset));
}
emit(cond | d*B22 | 0xD0*B20 | ip.code()*B16 | sd*B12 | 0xA*B8);
}
}
void Assembler::vstr(const SwVfpRegister src,
const MemOperand& operand,
const Condition cond) {
ASSERT(!operand.rm().is_valid());
ASSERT(operand.am_ == Offset);
vldr(src, operand.rn(), operand.offset(), cond);
}
static void DoubleAsTwoUInt32(double d, uint32_t* lo, uint32_t* hi) {
uint64_t i;
memcpy(&i, &d, 8);
*lo = i & 0xffffffff;
*hi = i >> 32;
}
// Only works for little endian floating point formats.
// We don't support VFP on the mixed endian floating point platform.
static bool FitsVMOVDoubleImmediate(double d, uint32_t *encoding) {
ASSERT(CpuFeatures::IsEnabled(VFP3));
// VMOV can accept an immediate of the form:
//
// +/- m * 2^(-n) where 16 <= m <= 31 and 0 <= n <= 7
//
// The immediate is encoded using an 8-bit quantity, comprised of two
// 4-bit fields. For an 8-bit immediate of the form:
//
// [abcdefgh]
//
// where a is the MSB and h is the LSB, an immediate 64-bit double can be
// created of the form:
//
// [aBbbbbbb,bbcdefgh,00000000,00000000,
// 00000000,00000000,00000000,00000000]
//
// where B = ~b.
//
uint32_t lo, hi;
DoubleAsTwoUInt32(d, &lo, &hi);
// The most obvious constraint is the long block of zeroes.
if ((lo != 0) || ((hi & 0xffff) != 0)) {
return false;
}
// Bits 62:55 must be all clear or all set.
if (((hi & 0x3fc00000) != 0) && ((hi & 0x3fc00000) != 0x3fc00000)) {
return false;
}
// Bit 63 must be NOT bit 62.
if (((hi ^ (hi << 1)) & (0x40000000)) == 0) {
return false;
}
// Create the encoded immediate in the form:
// [00000000,0000abcd,00000000,0000efgh]
*encoding = (hi >> 16) & 0xf; // Low nybble.
*encoding |= (hi >> 4) & 0x70000; // Low three bits of the high nybble.
*encoding |= (hi >> 12) & 0x80000; // Top bit of the high nybble.
return true;
}
void Assembler::vmov(const DwVfpRegister dst,
double imm,
const Condition cond) {
// Dd = immediate
// Instruction details available in ARM DDI 0406B, A8-640.
ASSERT(CpuFeatures::IsEnabled(VFP3));
uint32_t enc;
if (FitsVMOVDoubleImmediate(imm, &enc)) {
// The double can be encoded in the instruction.
emit(cond | 0xE*B24 | 0xB*B20 | dst.code()*B12 | 0xB*B8 | enc);
} else {
// Synthesise the double from ARM immediates. This could be implemented
// using vldr from a constant pool.
uint32_t lo, hi;
DoubleAsTwoUInt32(imm, &lo, &hi);
if (lo == hi) {
// If the lo and hi parts of the double are equal, the literal is easier
// to create. This is the case with 0.0.
mov(ip, Operand(lo));
vmov(dst, ip, ip);
} else {
// Move the low part of the double into the lower of the corresponsing S
// registers of D register dst.
mov(ip, Operand(lo));
vmov(dst.low(), ip, cond);
// Move the high part of the double into the higher of the corresponsing S
// registers of D register dst.
mov(ip, Operand(hi));
vmov(dst.high(), ip, cond);
}
}
}
void Assembler::vmov(const SwVfpRegister dst,
const SwVfpRegister src,
const Condition cond) {
// Sd = Sm
// Instruction details available in ARM DDI 0406B, A8-642.
ASSERT(CpuFeatures::IsEnabled(VFP3));
int sd, d, sm, m;
dst.split_code(&sd, &d);
src.split_code(&sm, &m);
emit(cond | 0xE*B24 | d*B22 | 0xB*B20 | sd*B12 | 0xA*B8 | B6 | m*B5 | sm);
}
void Assembler::vmov(const DwVfpRegister dst,
const DwVfpRegister src,
const Condition cond) {
// Dd = Dm
// Instruction details available in ARM DDI 0406B, A8-642.
ASSERT(CpuFeatures::IsEnabled(VFP3));
emit(cond | 0xE*B24 | 0xB*B20 |
dst.code()*B12 | 0x5*B9 | B8 | B6 | src.code());
}
void Assembler::vmov(const DwVfpRegister dst,
const Register src1,
const Register src2,
const Condition cond) {
// Dm = <Rt,Rt2>.
// Instruction details available in ARM DDI 0406A, A8-646.
// cond(31-28) | 1100(27-24)| 010(23-21) | op=0(20) | Rt2(19-16) |
// Rt(15-12) | 1011(11-8) | 00(7-6) | M(5) | 1(4) | Vm
ASSERT(CpuFeatures::IsEnabled(VFP3));
ASSERT(!src1.is(pc) && !src2.is(pc));
emit(cond | 0xC*B24 | B22 | src2.code()*B16 |
src1.code()*B12 | 0xB*B8 | B4 | dst.code());
}
void Assembler::vmov(const Register dst1,
const Register dst2,
const DwVfpRegister src,
const Condition cond) {
// <Rt,Rt2> = Dm.
// Instruction details available in ARM DDI 0406A, A8-646.
// cond(31-28) | 1100(27-24)| 010(23-21) | op=1(20) | Rt2(19-16) |
// Rt(15-12) | 1011(11-8) | 00(7-6) | M(5) | 1(4) | Vm
ASSERT(CpuFeatures::IsEnabled(VFP3));
ASSERT(!dst1.is(pc) && !dst2.is(pc));
emit(cond | 0xC*B24 | B22 | B20 | dst2.code()*B16 |
dst1.code()*B12 | 0xB*B8 | B4 | src.code());
}
void Assembler::vmov(const SwVfpRegister dst,
const Register src,
const Condition cond) {
// Sn = Rt.
// Instruction details available in ARM DDI 0406A, A8-642.
// cond(31-28) | 1110(27-24)| 000(23-21) | op=0(20) | Vn(19-16) |
// Rt(15-12) | 1010(11-8) | N(7)=0 | 00(6-5) | 1(4) | 0000(3-0)
ASSERT(CpuFeatures::IsEnabled(VFP3));
ASSERT(!src.is(pc));
int sn, n;
dst.split_code(&sn, &n);
emit(cond | 0xE*B24 | sn*B16 | src.code()*B12 | 0xA*B8 | n*B7 | B4);
}
void Assembler::vmov(const Register dst,
const SwVfpRegister src,
const Condition cond) {
// Rt = Sn.
// Instruction details available in ARM DDI 0406A, A8-642.
// cond(31-28) | 1110(27-24)| 000(23-21) | op=1(20) | Vn(19-16) |
// Rt(15-12) | 1010(11-8) | N(7)=0 | 00(6-5) | 1(4) | 0000(3-0)
ASSERT(CpuFeatures::IsEnabled(VFP3));
ASSERT(!dst.is(pc));
int sn, n;
src.split_code(&sn, &n);
emit(cond | 0xE*B24 | B20 | sn*B16 | dst.code()*B12 | 0xA*B8 | n*B7 | B4);
}
// Type of data to read from or write to VFP register.
// Used as specifier in generic vcvt instruction.
enum VFPType { S32, U32, F32, F64 };
static bool IsSignedVFPType(VFPType type) {
switch (type) {
case S32:
return true;
case U32:
return false;
default:
UNREACHABLE();
return false;
}
}
static bool IsIntegerVFPType(VFPType type) {
switch (type) {
case S32:
case U32:
return true;
case F32:
case F64:
return false;
default:
UNREACHABLE();
return false;
}
}
static bool IsDoubleVFPType(VFPType type) {
switch (type) {
case F32:
return false;
case F64:
return true;
default:
UNREACHABLE();
return false;
}
}
// Split five bit reg_code based on size of reg_type.
// 32-bit register codes are Vm:M
// 64-bit register codes are M:Vm
// where Vm is four bits, and M is a single bit.
static void SplitRegCode(VFPType reg_type,
int reg_code,
int* vm,
int* m) {
ASSERT((reg_code >= 0) && (reg_code <= 31));
if (IsIntegerVFPType(reg_type) || !IsDoubleVFPType(reg_type)) {
// 32 bit type.
*m = reg_code & 0x1;
*vm = reg_code >> 1;
} else {
// 64 bit type.
*m = (reg_code & 0x10) >> 4;
*vm = reg_code & 0x0F;
}
}
// Encode vcvt.src_type.dst_type instruction.
static Instr EncodeVCVT(const VFPType dst_type,
const int dst_code,
const VFPType src_type,
const int src_code,
VFPConversionMode mode,
const Condition cond) {
ASSERT(src_type != dst_type);
int D, Vd, M, Vm;
SplitRegCode(src_type, src_code, &Vm, &M);
SplitRegCode(dst_type, dst_code, &Vd, &D);
if (IsIntegerVFPType(dst_type) || IsIntegerVFPType(src_type)) {
// Conversion between IEEE floating point and 32-bit integer.
// Instruction details available in ARM DDI 0406B, A8.6.295.
// cond(31-28) | 11101(27-23)| D(22) | 11(21-20) | 1(19) | opc2(18-16) |
// Vd(15-12) | 101(11-9) | sz(8) | op(7) | 1(6) | M(5) | 0(4) | Vm(3-0)
ASSERT(!IsIntegerVFPType(dst_type) || !IsIntegerVFPType(src_type));
int sz, opc2, op;
if (IsIntegerVFPType(dst_type)) {
opc2 = IsSignedVFPType(dst_type) ? 0x5 : 0x4;
sz = IsDoubleVFPType(src_type) ? 0x1 : 0x0;
op = mode;
} else {
ASSERT(IsIntegerVFPType(src_type));
opc2 = 0x0;
sz = IsDoubleVFPType(dst_type) ? 0x1 : 0x0;
op = IsSignedVFPType(src_type) ? 0x1 : 0x0;
}
return (cond | 0xE*B24 | B23 | D*B22 | 0x3*B20 | B19 | opc2*B16 |
Vd*B12 | 0x5*B9 | sz*B8 | op*B7 | B6 | M*B5 | Vm);
} else {
// Conversion between IEEE double and single precision.
// Instruction details available in ARM DDI 0406B, A8.6.298.
// cond(31-28) | 11101(27-23)| D(22) | 11(21-20) | 0111(19-16) |
// Vd(15-12) | 101(11-9) | sz(8) | 1(7) | 1(6) | M(5) | 0(4) | Vm(3-0)
int sz = IsDoubleVFPType(src_type) ? 0x1 : 0x0;
return (cond | 0xE*B24 | B23 | D*B22 | 0x3*B20 | 0x7*B16 |
Vd*B12 | 0x5*B9 | sz*B8 | B7 | B6 | M*B5 | Vm);
}
}
void Assembler::vcvt_f64_s32(const DwVfpRegister dst,
const SwVfpRegister src,
VFPConversionMode mode,
const Condition cond) {
ASSERT(CpuFeatures::IsEnabled(VFP3));
emit(EncodeVCVT(F64, dst.code(), S32, src.code(), mode, cond));
}
void Assembler::vcvt_f32_s32(const SwVfpRegister dst,
const SwVfpRegister src,
VFPConversionMode mode,
const Condition cond) {
ASSERT(CpuFeatures::IsEnabled(VFP3));
emit(EncodeVCVT(F32, dst.code(), S32, src.code(), mode, cond));
}
void Assembler::vcvt_f64_u32(const DwVfpRegister dst,
const SwVfpRegister src,
VFPConversionMode mode,
const Condition cond) {
ASSERT(CpuFeatures::IsEnabled(VFP3));
emit(EncodeVCVT(F64, dst.code(), U32, src.code(), mode, cond));
}
void Assembler::vcvt_s32_f64(const SwVfpRegister dst,
const DwVfpRegister src,
VFPConversionMode mode,
const Condition cond) {
ASSERT(CpuFeatures::IsEnabled(VFP3));
emit(EncodeVCVT(S32, dst.code(), F64, src.code(), mode, cond));
}
void Assembler::vcvt_u32_f64(const SwVfpRegister dst,
const DwVfpRegister src,
VFPConversionMode mode,
const Condition cond) {
ASSERT(CpuFeatures::IsEnabled(VFP3));
emit(EncodeVCVT(U32, dst.code(), F64, src.code(), mode, cond));
}
void Assembler::vcvt_f64_f32(const DwVfpRegister dst,
const SwVfpRegister src,
VFPConversionMode mode,
const Condition cond) {
ASSERT(CpuFeatures::IsEnabled(VFP3));
emit(EncodeVCVT(F64, dst.code(), F32, src.code(), mode, cond));
}
void Assembler::vcvt_f32_f64(const SwVfpRegister dst,
const DwVfpRegister src,
VFPConversionMode mode,
const Condition cond) {
ASSERT(CpuFeatures::IsEnabled(VFP3));
emit(EncodeVCVT(F32, dst.code(), F64, src.code(), mode, cond));
}
void Assembler::vabs(const DwVfpRegister dst,
const DwVfpRegister src,
const Condition cond) {
emit(cond | 0xE*B24 | 0xB*B20 | dst.code()*B12 |
0x5*B9 | B8 | 0x3*B6 | src.code());
}
void Assembler::vadd(const DwVfpRegister dst,
const DwVfpRegister src1,
const DwVfpRegister src2,
const Condition cond) {
// Dd = vadd(Dn, Dm) double precision floating point addition.
// Dd = D:Vd; Dm=M:Vm; Dn=N:Vm.
// Instruction details available in ARM DDI 0406A, A8-536.
// cond(31-28) | 11100(27-23)| D=?(22) | 11(21-20) | Vn(19-16) |
// Vd(15-12) | 101(11-9) | sz(8)=1 | N(7)=0 | 0(6) | M=?(5) | 0(4) | Vm(3-0)
ASSERT(CpuFeatures::IsEnabled(VFP3));
emit(cond | 0xE*B24 | 0x3*B20 | src1.code()*B16 |
dst.code()*B12 | 0x5*B9 | B8 | src2.code());
}
void Assembler::vsub(const DwVfpRegister dst,
const DwVfpRegister src1,
const DwVfpRegister src2,
const Condition cond) {
// Dd = vsub(Dn, Dm) double precision floating point subtraction.
// Dd = D:Vd; Dm=M:Vm; Dn=N:Vm.
// Instruction details available in ARM DDI 0406A, A8-784.
// cond(31-28) | 11100(27-23)| D=?(22) | 11(21-20) | Vn(19-16) |
// Vd(15-12) | 101(11-9) | sz(8)=1 | N(7)=0 | 1(6) | M=?(5) | 0(4) | Vm(3-0)
ASSERT(CpuFeatures::IsEnabled(VFP3));
emit(cond | 0xE*B24 | 0x3*B20 | src1.code()*B16 |
dst.code()*B12 | 0x5*B9 | B8 | B6 | src2.code());
}
void Assembler::vmul(const DwVfpRegister dst,
const DwVfpRegister src1,
const DwVfpRegister src2,
const Condition cond) {
// Dd = vmul(Dn, Dm) double precision floating point multiplication.
// Dd = D:Vd; Dm=M:Vm; Dn=N:Vm.
// Instruction details available in ARM DDI 0406A, A8-784.
// cond(31-28) | 11100(27-23)| D=?(22) | 10(21-20) | Vn(19-16) |
// Vd(15-12) | 101(11-9) | sz(8)=1 | N(7)=0 | 0(6) | M=?(5) | 0(4) | Vm(3-0)
ASSERT(CpuFeatures::IsEnabled(VFP3));
emit(cond | 0xE*B24 | 0x2*B20 | src1.code()*B16 |
dst.code()*B12 | 0x5*B9 | B8 | src2.code());
}
void Assembler::vdiv(const DwVfpRegister dst,
const DwVfpRegister src1,
const DwVfpRegister src2,
const Condition cond) {
// Dd = vdiv(Dn, Dm) double precision floating point division.
// Dd = D:Vd; Dm=M:Vm; Dn=N:Vm.
// Instruction details available in ARM DDI 0406A, A8-584.
// cond(31-28) | 11101(27-23)| D=?(22) | 00(21-20) | Vn(19-16) |
// Vd(15-12) | 101(11-9) | sz(8)=1 | N(7)=? | 0(6) | M=?(5) | 0(4) | Vm(3-0)
ASSERT(CpuFeatures::IsEnabled(VFP3));
emit(cond | 0xE*B24 | B23 | src1.code()*B16 |
dst.code()*B12 | 0x5*B9 | B8 | src2.code());
}
void Assembler::vcmp(const DwVfpRegister src1,
const DwVfpRegister src2,
const Condition cond) {
// vcmp(Dd, Dm) double precision floating point comparison.
// Instruction details available in ARM DDI 0406A, A8-570.
// cond(31-28) | 11101 (27-23)| D=?(22) | 11 (21-20) | 0100 (19-16) |
// Vd(15-12) | 101(11-9) | sz(8)=1 | E(7)=0 | 1(6) | M(5)=? | 0(4) | Vm(3-0)
ASSERT(CpuFeatures::IsEnabled(VFP3));
emit(cond | 0xE*B24 |B23 | 0x3*B20 | B18 |
src1.code()*B12 | 0x5*B9 | B8 | B6 | src2.code());
}
void Assembler::vcmp(const DwVfpRegister src1,
const double src2,
const Condition cond) {
// vcmp(Dd, Dm) double precision floating point comparison.
// Instruction details available in ARM DDI 0406A, A8-570.
// cond(31-28) | 11101 (27-23)| D=?(22) | 11 (21-20) | 0101 (19-16) |
// Vd(15-12) | 101(11-9) | sz(8)=1 | E(7)=0 | 1(6) | M(5)=? | 0(4) | 0000(3-0)
ASSERT(CpuFeatures::IsEnabled(VFP3));
ASSERT(src2 == 0.0);
emit(cond | 0xE*B24 |B23 | 0x3*B20 | B18 | B16 |
src1.code()*B12 | 0x5*B9 | B8 | B6);
}
void Assembler::vmsr(Register dst, Condition cond) {
// Instruction details available in ARM DDI 0406A, A8-652.
// cond(31-28) | 1110 (27-24) | 1110(23-20)| 0001 (19-16) |
// Rt(15-12) | 1010 (11-8) | 0(7) | 00 (6-5) | 1(4) | 0000(3-0)
ASSERT(CpuFeatures::IsEnabled(VFP3));
emit(cond | 0xE*B24 | 0xE*B20 | B16 |
dst.code()*B12 | 0xA*B8 | B4);
}
void Assembler::vmrs(Register dst, Condition cond) {
// Instruction details available in ARM DDI 0406A, A8-652.
// cond(31-28) | 1110 (27-24) | 1111(23-20)| 0001 (19-16) |
// Rt(15-12) | 1010 (11-8) | 0(7) | 00 (6-5) | 1(4) | 0000(3-0)
ASSERT(CpuFeatures::IsEnabled(VFP3));
emit(cond | 0xE*B24 | 0xF*B20 | B16 |
dst.code()*B12 | 0xA*B8 | B4);
}
void Assembler::vsqrt(const DwVfpRegister dst,
const DwVfpRegister src,
const Condition cond) {
// cond(31-28) | 11101 (27-23)| D=?(22) | 11 (21-20) | 0001 (19-16) |
// Vd(15-12) | 101(11-9) | sz(8)=1 | 11 (7-6) | M(5)=? | 0(4) | Vm(3-0)
ASSERT(CpuFeatures::IsEnabled(VFP3));
emit(cond | 0xE*B24 | B23 | 0x3*B20 | B16 |
dst.code()*B12 | 0x5*B9 | B8 | 3*B6 | src.code());
}
// Pseudo instructions.
void Assembler::nop(int type) {
// This is mov rx, rx.
ASSERT(0 <= type && type <= 14); // mov pc, pc is not a nop.
emit(al | 13*B21 | type*B12 | type);
}
bool Assembler::IsNop(Instr instr, int type) {
// Check for mov rx, rx where x = type.
ASSERT(0 <= type && type <= 14); // mov pc, pc is not a nop.
return instr == (al | 13*B21 | type*B12 | type);
}
bool Assembler::ImmediateFitsAddrMode1Instruction(int32_t imm32) {
uint32_t dummy1;
uint32_t dummy2;
return fits_shifter(imm32, &dummy1, &dummy2, NULL);
}
void Assembler::BlockConstPoolFor(int instructions) {
BlockConstPoolBefore(pc_offset() + instructions * kInstrSize);
}
// Debugging.
void Assembler::RecordJSReturn() {
positions_recorder()->WriteRecordedPositions();
CheckBuffer();
RecordRelocInfo(RelocInfo::JS_RETURN);
}
void Assembler::RecordDebugBreakSlot() {
positions_recorder()->WriteRecordedPositions();
CheckBuffer();
RecordRelocInfo(RelocInfo::DEBUG_BREAK_SLOT);
}
void Assembler::RecordComment(const char* msg) {
if (FLAG_code_comments) {
CheckBuffer();
RecordRelocInfo(RelocInfo::COMMENT, reinterpret_cast<intptr_t>(msg));
}
}
void Assembler::GrowBuffer() {
if (!own_buffer_) FATAL("external code buffer is too small");
// Compute new buffer size.
CodeDesc desc; // the new buffer
if (buffer_size_ < 4*KB) {
desc.buffer_size = 4*KB;
} else if (buffer_size_ < 1*MB) {
desc.buffer_size = 2*buffer_size_;
} else {
desc.buffer_size = buffer_size_ + 1*MB;
}
CHECK_GT(desc.buffer_size, 0); // no overflow
// Setup new buffer.
desc.buffer = NewArray<byte>(desc.buffer_size);
desc.instr_size = pc_offset();
desc.reloc_size = (buffer_ + buffer_size_) - reloc_info_writer.pos();
// Copy the data.
int pc_delta = desc.buffer - buffer_;
int rc_delta = (desc.buffer + desc.buffer_size) - (buffer_ + buffer_size_);
memmove(desc.buffer, buffer_, desc.instr_size);
memmove(reloc_info_writer.pos() + rc_delta,
reloc_info_writer.pos(), desc.reloc_size);
// Switch buffers.
DeleteArray(buffer_);
buffer_ = desc.buffer;
buffer_size_ = desc.buffer_size;
pc_ += pc_delta;
reloc_info_writer.Reposition(reloc_info_writer.pos() + rc_delta,
reloc_info_writer.last_pc() + pc_delta);
// None of our relocation types are pc relative pointing outside the code
// buffer nor pc absolute pointing inside the code buffer, so there is no need
// to relocate any emitted relocation entries.
// Relocate pending relocation entries.
for (int i = 0; i < num_prinfo_; i++) {
RelocInfo& rinfo = prinfo_[i];
ASSERT(rinfo.rmode() != RelocInfo::COMMENT &&
rinfo.rmode() != RelocInfo::POSITION);
if (rinfo.rmode() != RelocInfo::JS_RETURN) {
rinfo.set_pc(rinfo.pc() + pc_delta);
}
}
}
void Assembler::db(uint8_t data) {
// No relocation info should be pending while using db. db is used
// to write pure data with no pointers and the constant pool should
// be emitted before using db.
ASSERT(num_prinfo_ == 0);
CheckBuffer();
*reinterpret_cast<uint8_t*>(pc_) = data;
pc_ += sizeof(uint8_t);
}
void Assembler::dd(uint32_t data) {
// No relocation info should be pending while using dd. dd is used
// to write pure data with no pointers and the constant pool should
// be emitted before using dd.
ASSERT(num_prinfo_ == 0);
CheckBuffer();
*reinterpret_cast<uint32_t*>(pc_) = data;
pc_ += sizeof(uint32_t);
}
void Assembler::RecordRelocInfo(RelocInfo::Mode rmode, intptr_t data) {
RelocInfo rinfo(pc_, rmode, data); // we do not try to reuse pool constants
if (rmode >= RelocInfo::JS_RETURN && rmode <= RelocInfo::DEBUG_BREAK_SLOT) {
// Adjust code for new modes.
ASSERT(RelocInfo::IsDebugBreakSlot(rmode)
|| RelocInfo::IsJSReturn(rmode)
|| RelocInfo::IsComment(rmode)
|| RelocInfo::IsPosition(rmode));
// These modes do not need an entry in the constant pool.
} else {
ASSERT(num_prinfo_ < kMaxNumPRInfo);
prinfo_[num_prinfo_++] = rinfo;
// Make sure the constant pool is not emitted in place of the next
// instruction for which we just recorded relocation info.
BlockConstPoolBefore(pc_offset() + kInstrSize);
}
if (rinfo.rmode() != RelocInfo::NONE) {
// Don't record external references unless the heap will be serialized.
if (rmode == RelocInfo::EXTERNAL_REFERENCE) {
#ifdef DEBUG
if (!Serializer::enabled()) {
Serializer::TooLateToEnableNow();
}
#endif
if (!Serializer::enabled() && !FLAG_debug_code) {
return;
}
}
ASSERT(buffer_space() >= kMaxRelocSize); // too late to grow buffer here
reloc_info_writer.Write(&rinfo);
}
}
void Assembler::CheckConstPool(bool force_emit, bool require_jump) {
// Calculate the offset of the next check. It will be overwritten
// when a const pool is generated or when const pools are being
// blocked for a specific range.
next_buffer_check_ = pc_offset() + kCheckConstInterval;
// There is nothing to do if there are no pending relocation info entries.
if (num_prinfo_ == 0) return;
// We emit a constant pool at regular intervals of about kDistBetweenPools
// or when requested by parameter force_emit (e.g. after each function).
// We prefer not to emit a jump unless the max distance is reached or if we
// are running low on slots, which can happen if a lot of constants are being
// emitted (e.g. --debug-code and many static references).
int dist = pc_offset() - last_const_pool_end_;
if (!force_emit && dist < kMaxDistBetweenPools &&
(require_jump || dist < kDistBetweenPools) &&
// TODO(1236125): Cleanup the "magic" number below. We know that
// the code generation will test every kCheckConstIntervalInst.
// Thus we are safe as long as we generate less than 7 constant
// entries per instruction.
(num_prinfo_ < (kMaxNumPRInfo - (7 * kCheckConstIntervalInst)))) {
return;
}
// If we did not return by now, we need to emit the constant pool soon.
// However, some small sequences of instructions must not be broken up by the
// insertion of a constant pool; such sequences are protected by setting
// either const_pool_blocked_nesting_ or no_const_pool_before_, which are
// both checked here. Also, recursive calls to CheckConstPool are blocked by
// no_const_pool_before_.
if (const_pool_blocked_nesting_ > 0 || pc_offset() < no_const_pool_before_) {
// Emission is currently blocked; make sure we try again as soon as
// possible.
if (const_pool_blocked_nesting_ > 0) {
next_buffer_check_ = pc_offset() + kInstrSize;
} else {
next_buffer_check_ = no_const_pool_before_;
}
// Something is wrong if emission is forced and blocked at the same time.
ASSERT(!force_emit);
return;
}
int jump_instr = require_jump ? kInstrSize : 0;
// Check that the code buffer is large enough before emitting the constant
// pool and relocation information (include the jump over the pool and the
// constant pool marker).
int max_needed_space =
jump_instr + kInstrSize + num_prinfo_*(kInstrSize + kMaxRelocSize);
while (buffer_space() <= (max_needed_space + kGap)) GrowBuffer();
// Block recursive calls to CheckConstPool.
BlockConstPoolBefore(pc_offset() + jump_instr + kInstrSize +
num_prinfo_*kInstrSize);
// Don't bother to check for the emit calls below.
next_buffer_check_ = no_const_pool_before_;
// Emit jump over constant pool if necessary.
Label after_pool;
if (require_jump) b(&after_pool);
RecordComment("[ Constant Pool");
// Put down constant pool marker "Undefined instruction" as specified by
// A3.1 Instruction set encoding.
emit(0x03000000 | num_prinfo_);
// Emit constant pool entries.
for (int i = 0; i < num_prinfo_; i++) {
RelocInfo& rinfo = prinfo_[i];
ASSERT(rinfo.rmode() != RelocInfo::COMMENT &&
rinfo.rmode() != RelocInfo::POSITION &&
rinfo.rmode() != RelocInfo::STATEMENT_POSITION);
Instr instr = instr_at(rinfo.pc());
// Instruction to patch must be a ldr/str [pc, #offset].
// P and U set, B and W clear, Rn == pc, offset12 still 0.
ASSERT((instr & (7*B25 | P | U | B | W | 15*B16 | kOff12Mask)) ==
(2*B25 | P | U | pc.code()*B16));
int delta = pc_ - rinfo.pc() - 8;
ASSERT(delta >= -4); // instr could be ldr pc, [pc, #-4] followed by targ32
if (delta < 0) {
instr &= ~U;
delta = -delta;
}
ASSERT(is_uint12(delta));
instr_at_put(rinfo.pc(), instr + delta);
emit(rinfo.data());
}
num_prinfo_ = 0;
last_const_pool_end_ = pc_offset();
RecordComment("]");
if (after_pool.is_linked()) {
bind(&after_pool);
}
// Since a constant pool was just emitted, move the check offset forward by
// the standard interval.
next_buffer_check_ = pc_offset() + kCheckConstInterval;
}
} } // namespace v8::internal
#endif // V8_TARGET_ARCH_ARM