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v8/src/mips/assembler-mips.cc
danno@chromium.org a92a9c8a2c MIPS: Changed "marked" nops to use sll(zero_reg, at, type). 
We use marking bits in nops (in the 'sa' field) for debug markers, and for some IC stuff. A normal NOP in mips is sll(zero_reg, zero_reg, 0), where the 0 is a 5 bit immediate field in 'sa'.

See enum NopMarkerTypes at around line 654 of assembler-mips.h

The problem is that these markers use encodings that are reserved for the 'ssnop' and 'ehb' instructions. These are instructions used for hazard barriers.

It does not break anything, but it will slow things down a little bit as some pipeline stages are cleared, etc.

This commit changes the "marked" NOPs to sll(zero_reg, at, type) instructions, which is also a NOP operation on MIPS.

BUG=
TEST=

Review URL: https://codereview.chromium.org/10990110
Patch from Akos Palfi <palfia@homejinni.com>.

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@12657 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
2012-10-04 09:46:50 +00:00

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// 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 2012 the V8 project authors. All rights reserved.
#include "v8.h"
#if defined(V8_TARGET_ARCH_MIPS)
#include "mips/assembler-mips-inl.h"
#include "serialize.h"
namespace v8 {
namespace internal {
#ifdef DEBUG
bool CpuFeatures::initialized_ = false;
#endif
unsigned CpuFeatures::supported_ = 0;
unsigned CpuFeatures::found_by_runtime_probing_ = 0;
// Get the CPU features enabled by the build. For cross compilation the
// preprocessor symbols CAN_USE_FPU_INSTRUCTIONS
// can be defined to enable FPU instructions when building the
// snapshot.
static uint64_t CpuFeaturesImpliedByCompiler() {
uint64_t answer = 0;
#ifdef CAN_USE_FPU_INSTRUCTIONS
answer |= 1u << FPU;
#endif // def CAN_USE_FPU_INSTRUCTIONS
#ifdef __mips__
// If the compiler is allowed to use FPU then we can use FPU too in our code
// generation even when generating snapshots. This won't work for cross
// compilation.
#if(defined(__mips_hard_float) && __mips_hard_float != 0)
answer |= 1u << FPU;
#endif // defined(__mips_hard_float) && __mips_hard_float != 0
#endif // def __mips__
return answer;
}
void CpuFeatures::Probe() {
unsigned standard_features = (OS::CpuFeaturesImpliedByPlatform() |
CpuFeaturesImpliedByCompiler());
ASSERT(supported_ == 0 || supported_ == standard_features);
#ifdef DEBUG
initialized_ = true;
#endif
// Get the features implied by the OS and the compiler settings. This is the
// minimal set of features which is also allowed for generated code in the
// snapshot.
supported_ |= standard_features;
if (Serializer::enabled()) {
// No probing for features if we might serialize (generate snapshot).
return;
}
// If the compiler is allowed to use fpu then we can use fpu too in our
// code generation.
#if !defined(__mips__)
// For the simulator=mips build, use FPU when FLAG_enable_fpu is enabled.
if (FLAG_enable_fpu) {
supported_ |= 1u << FPU;
}
#else
// Probe for additional features not already known to be available.
if (OS::MipsCpuHasFeature(FPU)) {
// This implementation also sets the FPU flags if
// runtime detection of FPU returns true.
supported_ |= 1u << FPU;
found_by_runtime_probing_ |= 1u << FPU;
}
#endif
}
int ToNumber(Register reg) {
ASSERT(reg.is_valid());
const int kNumbers[] = {
0, // zero_reg
1, // at
2, // v0
3, // v1
4, // a0
5, // a1
6, // a2
7, // a3
8, // t0
9, // t1
10, // t2
11, // t3
12, // t4
13, // t5
14, // t6
15, // t7
16, // s0
17, // s1
18, // s2
19, // s3
20, // s4
21, // s5
22, // s6
23, // s7
24, // t8
25, // t9
26, // k0
27, // k1
28, // gp
29, // sp
30, // fp
31, // ra
};
return kNumbers[reg.code()];
}
Register ToRegister(int num) {
ASSERT(num >= 0 && num < kNumRegisters);
const Register kRegisters[] = {
zero_reg,
at,
v0, v1,
a0, a1, a2, a3,
t0, t1, t2, t3, t4, t5, t6, t7,
s0, s1, s2, s3, s4, s5, s6, s7,
t8, t9,
k0, k1,
gp,
sp,
fp,
ra
};
return kRegisters[num];
}
// -----------------------------------------------------------------------------
// Implementation of RelocInfo.
const int RelocInfo::kApplyMask = RelocInfo::kCodeTargetMask |
1 << RelocInfo::INTERNAL_REFERENCE;
bool RelocInfo::IsCodedSpecially() {
// The deserializer needs to know whether a pointer is specially coded. Being
// specially coded on MIPS means that it is a lui/ori instruction, and that is
// always the case inside code objects.
return true;
}
// Patch the code at the current address with the supplied instructions.
void RelocInfo::PatchCode(byte* instructions, int instruction_count) {
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_MIPS();
}
// -----------------------------------------------------------------------------
// Implementation of Operand and MemOperand.
// See assembler-mips-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;
}
}
MemOperand::MemOperand(Register rm, int32_t offset) : Operand(rm) {
offset_ = offset;
}
// -----------------------------------------------------------------------------
// Specific instructions, constants, and masks.
static const int kNegOffset = 0x00008000;
// addiu(sp, sp, 4) aka Pop() operation or part of Pop(r)
// operations as post-increment of sp.
const Instr kPopInstruction = ADDIU | (kRegister_sp_Code << kRsShift)
| (kRegister_sp_Code << kRtShift) | (kPointerSize & kImm16Mask);
// addiu(sp, sp, -4) part of Push(r) operation as pre-decrement of sp.
const Instr kPushInstruction = ADDIU | (kRegister_sp_Code << kRsShift)
| (kRegister_sp_Code << kRtShift) | (-kPointerSize & kImm16Mask);
// sw(r, MemOperand(sp, 0))
const Instr kPushRegPattern = SW | (kRegister_sp_Code << kRsShift)
| (0 & kImm16Mask);
// lw(r, MemOperand(sp, 0))
const Instr kPopRegPattern = LW | (kRegister_sp_Code << kRsShift)
| (0 & kImm16Mask);
const Instr kLwRegFpOffsetPattern = LW | (kRegister_fp_Code << kRsShift)
| (0 & kImm16Mask);
const Instr kSwRegFpOffsetPattern = SW | (kRegister_fp_Code << kRsShift)
| (0 & kImm16Mask);
const Instr kLwRegFpNegOffsetPattern = LW | (kRegister_fp_Code << kRsShift)
| (kNegOffset & kImm16Mask);
const Instr kSwRegFpNegOffsetPattern = SW | (kRegister_fp_Code << kRsShift)
| (kNegOffset & kImm16Mask);
// A mask for the Rt register for push, pop, lw, sw instructions.
const Instr kRtMask = kRtFieldMask;
const Instr kLwSwInstrTypeMask = 0xffe00000;
const Instr kLwSwInstrArgumentMask = ~kLwSwInstrTypeMask;
const Instr kLwSwOffsetMask = kImm16Mask;
// Spare buffer.
static const int kMinimalBufferSize = 4 * KB;
Assembler::Assembler(Isolate* arg_isolate, void* buffer, int buffer_size)
: AssemblerBase(arg_isolate),
recorded_ast_id_(TypeFeedbackId::None()),
positions_recorder_(this),
emit_debug_code_(FLAG_debug_code) {
if (buffer == NULL) {
// Do our own buffer management.
if (buffer_size <= kMinimalBufferSize) {
buffer_size = kMinimalBufferSize;
if (isolate()->assembler_spare_buffer() != NULL) {
buffer = isolate()->assembler_spare_buffer();
isolate()->set_assembler_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;
}
// Set up buffer pointers.
ASSERT(buffer_ != NULL);
pc_ = buffer_;
reloc_info_writer.Reposition(buffer_ + buffer_size, pc_);
last_trampoline_pool_end_ = 0;
no_trampoline_pool_before_ = 0;
trampoline_pool_blocked_nesting_ = 0;
// We leave space (16 * kTrampolineSlotsSize)
// for BlockTrampolinePoolScope buffer.
next_buffer_check_ = kMaxBranchOffset - kTrampolineSlotsSize * 16;
internal_trampoline_exception_ = false;
last_bound_pos_ = 0;
trampoline_emitted_ = false;
unbound_labels_count_ = 0;
block_buffer_growth_ = false;
ClearRecordedAstId();
}
Assembler::~Assembler() {
if (own_buffer_) {
if (isolate()->assembler_spare_buffer() == NULL &&
buffer_size_ == kMinimalBufferSize) {
isolate()->set_assembler_spare_buffer(buffer_);
} else {
DeleteArray(buffer_);
}
}
}
void Assembler::GetCode(CodeDesc* desc) {
ASSERT(pc_ <= reloc_info_writer.pos()); // No overlap.
// Set up 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() {
// No advantage to aligning branch/call targets to more than
// single instruction, that I am aware of.
Align(4);
}
Register Assembler::GetRtReg(Instr instr) {
Register rt;
rt.code_ = (instr & kRtFieldMask) >> kRtShift;
return rt;
}
Register Assembler::GetRsReg(Instr instr) {
Register rs;
rs.code_ = (instr & kRsFieldMask) >> kRsShift;
return rs;
}
Register Assembler::GetRdReg(Instr instr) {
Register rd;
rd.code_ = (instr & kRdFieldMask) >> kRdShift;
return rd;
}
uint32_t Assembler::GetRt(Instr instr) {
return (instr & kRtFieldMask) >> kRtShift;
}
uint32_t Assembler::GetRtField(Instr instr) {
return instr & kRtFieldMask;
}
uint32_t Assembler::GetRs(Instr instr) {
return (instr & kRsFieldMask) >> kRsShift;
}
uint32_t Assembler::GetRsField(Instr instr) {
return instr & kRsFieldMask;
}
uint32_t Assembler::GetRd(Instr instr) {
return (instr & kRdFieldMask) >> kRdShift;
}
uint32_t Assembler::GetRdField(Instr instr) {
return instr & kRdFieldMask;
}
uint32_t Assembler::GetSa(Instr instr) {
return (instr & kSaFieldMask) >> kSaShift;
}
uint32_t Assembler::GetSaField(Instr instr) {
return instr & kSaFieldMask;
}
uint32_t Assembler::GetOpcodeField(Instr instr) {
return instr & kOpcodeMask;
}
uint32_t Assembler::GetFunction(Instr instr) {
return (instr & kFunctionFieldMask) >> kFunctionShift;
}
uint32_t Assembler::GetFunctionField(Instr instr) {
return instr & kFunctionFieldMask;
}
uint32_t Assembler::GetImmediate16(Instr instr) {
return instr & kImm16Mask;
}
uint32_t Assembler::GetLabelConst(Instr instr) {
return instr & ~kImm16Mask;
}
bool Assembler::IsPop(Instr instr) {
return (instr & ~kRtMask) == kPopRegPattern;
}
bool Assembler::IsPush(Instr instr) {
return (instr & ~kRtMask) == kPushRegPattern;
}
bool Assembler::IsSwRegFpOffset(Instr instr) {
return ((instr & kLwSwInstrTypeMask) == kSwRegFpOffsetPattern);
}
bool Assembler::IsLwRegFpOffset(Instr instr) {
return ((instr & kLwSwInstrTypeMask) == kLwRegFpOffsetPattern);
}
bool Assembler::IsSwRegFpNegOffset(Instr instr) {
return ((instr & (kLwSwInstrTypeMask | kNegOffset)) ==
kSwRegFpNegOffsetPattern);
}
bool Assembler::IsLwRegFpNegOffset(Instr instr) {
return ((instr & (kLwSwInstrTypeMask | kNegOffset)) ==
kLwRegFpNegOffsetPattern);
}
// 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 value in the instruction of -1,
// which is an otherwise illegal value (branch -1 is inf loop).
// The instruction 16-bit offset field addresses 32-bit words, but in
// code is conv to an 18-bit value addressing bytes, hence the -4 value.
const int kEndOfChain = -4;
// Determines the end of the Jump chain (a subset of the label link chain).
const int kEndOfJumpChain = 0;
bool Assembler::IsBranch(Instr instr) {
uint32_t opcode = GetOpcodeField(instr);
uint32_t rt_field = GetRtField(instr);
uint32_t rs_field = GetRsField(instr);
uint32_t label_constant = GetLabelConst(instr);
// Checks if the instruction is a branch.
return opcode == BEQ ||
opcode == BNE ||
opcode == BLEZ ||
opcode == BGTZ ||
opcode == BEQL ||
opcode == BNEL ||
opcode == BLEZL ||
opcode == BGTZL ||
(opcode == REGIMM && (rt_field == BLTZ || rt_field == BGEZ ||
rt_field == BLTZAL || rt_field == BGEZAL)) ||
(opcode == COP1 && rs_field == BC1) || // Coprocessor branch.
label_constant == 0; // Emitted label const in reg-exp engine.
}
bool Assembler::IsBeq(Instr instr) {
return GetOpcodeField(instr) == BEQ;
}
bool Assembler::IsBne(Instr instr) {
return GetOpcodeField(instr) == BNE;
}
bool Assembler::IsJump(Instr instr) {
uint32_t opcode = GetOpcodeField(instr);
uint32_t rt_field = GetRtField(instr);
uint32_t rd_field = GetRdField(instr);
uint32_t function_field = GetFunctionField(instr);
// Checks if the instruction is a jump.
return opcode == J || opcode == JAL ||
(opcode == SPECIAL && rt_field == 0 &&
((function_field == JALR) || (rd_field == 0 && (function_field == JR))));
}
bool Assembler::IsJ(Instr instr) {
uint32_t opcode = GetOpcodeField(instr);
// Checks if the instruction is a jump.
return opcode == J;
}
bool Assembler::IsJal(Instr instr) {
return GetOpcodeField(instr) == JAL;
}
bool Assembler::IsJr(Instr instr) {
return GetOpcodeField(instr) == SPECIAL && GetFunctionField(instr) == JR;
}
bool Assembler::IsJalr(Instr instr) {
return GetOpcodeField(instr) == SPECIAL && GetFunctionField(instr) == JALR;
}
bool Assembler::IsLui(Instr instr) {
uint32_t opcode = GetOpcodeField(instr);
// Checks if the instruction is a load upper immediate.
return opcode == LUI;
}
bool Assembler::IsOri(Instr instr) {
uint32_t opcode = GetOpcodeField(instr);
// Checks if the instruction is a load upper immediate.
return opcode == ORI;
}
bool Assembler::IsNop(Instr instr, unsigned int type) {
// See Assembler::nop(type).
ASSERT(type < 32);
uint32_t opcode = GetOpcodeField(instr);
uint32_t function = GetFunctionField(instr);
uint32_t rt = GetRt(instr);
uint32_t rd = GetRd(instr);
uint32_t sa = GetSa(instr);
// Traditional mips nop == sll(zero_reg, zero_reg, 0)
// When marking non-zero type, use sll(zero_reg, at, type)
// to avoid use of mips ssnop and ehb special encodings
// of the sll instruction.
Register nop_rt_reg = (type == 0) ? zero_reg : at;
bool ret = (opcode == SPECIAL && function == SLL &&
rd == static_cast<uint32_t>(ToNumber(zero_reg)) &&
rt == static_cast<uint32_t>(ToNumber(nop_rt_reg)) &&
sa == type);
return ret;
}
int32_t Assembler::GetBranchOffset(Instr instr) {
ASSERT(IsBranch(instr));
return ((int16_t)(instr & kImm16Mask)) << 2;
}
bool Assembler::IsLw(Instr instr) {
return ((instr & kOpcodeMask) == LW);
}
int16_t Assembler::GetLwOffset(Instr instr) {
ASSERT(IsLw(instr));
return ((instr & kImm16Mask));
}
Instr Assembler::SetLwOffset(Instr instr, int16_t offset) {
ASSERT(IsLw(instr));
// We actually create a new lw instruction based on the original one.
Instr temp_instr = LW | (instr & kRsFieldMask) | (instr & kRtFieldMask)
| (offset & kImm16Mask);
return temp_instr;
}
bool Assembler::IsSw(Instr instr) {
return ((instr & kOpcodeMask) == SW);
}
Instr Assembler::SetSwOffset(Instr instr, int16_t offset) {
ASSERT(IsSw(instr));
return ((instr & ~kImm16Mask) | (offset & kImm16Mask));
}
bool Assembler::IsAddImmediate(Instr instr) {
return ((instr & kOpcodeMask) == ADDIU);
}
Instr Assembler::SetAddImmediateOffset(Instr instr, int16_t offset) {
ASSERT(IsAddImmediate(instr));
return ((instr & ~kImm16Mask) | (offset & kImm16Mask));
}
bool Assembler::IsAndImmediate(Instr instr) {
return GetOpcodeField(instr) == ANDI;
}
int Assembler::target_at(int32_t pos) {
Instr instr = instr_at(pos);
if ((instr & ~kImm16Mask) == 0) {
// Emitted label constant, not part of a branch.
if (instr == 0) {
return kEndOfChain;
} else {
int32_t imm18 =((instr & static_cast<int32_t>(kImm16Mask)) << 16) >> 14;
return (imm18 + pos);
}
}
// Check we have a branch or jump instruction.
ASSERT(IsBranch(instr) || IsJ(instr) || IsLui(instr));
// Do NOT change this to <<2. We rely on arithmetic shifts here, assuming
// the compiler uses arithmectic shifts for signed integers.
if (IsBranch(instr)) {
int32_t imm18 = ((instr & static_cast<int32_t>(kImm16Mask)) << 16) >> 14;
if (imm18 == kEndOfChain) {
// EndOfChain sentinel is returned directly, not relative to pc or pos.
return kEndOfChain;
} else {
return pos + kBranchPCOffset + imm18;
}
} else if (IsLui(instr)) {
Instr instr_lui = instr_at(pos + 0 * Assembler::kInstrSize);
Instr instr_ori = instr_at(pos + 1 * Assembler::kInstrSize);
ASSERT(IsOri(instr_ori));
int32_t imm = (instr_lui & static_cast<int32_t>(kImm16Mask)) << kLuiShift;
imm |= (instr_ori & static_cast<int32_t>(kImm16Mask));
if (imm == kEndOfJumpChain) {
// EndOfChain sentinel is returned directly, not relative to pc or pos.
return kEndOfChain;
} else {
uint32_t instr_address = reinterpret_cast<int32_t>(buffer_ + pos);
int32_t delta = instr_address - imm;
ASSERT(pos > delta);
return pos - delta;
}
} else {
int32_t imm28 = (instr & static_cast<int32_t>(kImm26Mask)) << 2;
if (imm28 == kEndOfJumpChain) {
// EndOfChain sentinel is returned directly, not relative to pc or pos.
return kEndOfChain;
} else {
uint32_t instr_address = reinterpret_cast<int32_t>(buffer_ + pos);
instr_address &= kImm28Mask;
int32_t delta = instr_address - imm28;
ASSERT(pos > delta);
return pos - delta;
}
}
}
void Assembler::target_at_put(int32_t pos, int32_t target_pos) {
Instr instr = instr_at(pos);
if ((instr & ~kImm16Mask) == 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;
}
ASSERT(IsBranch(instr) || IsJ(instr) || IsLui(instr));
if (IsBranch(instr)) {
int32_t imm18 = target_pos - (pos + kBranchPCOffset);
ASSERT((imm18 & 3) == 0);
instr &= ~kImm16Mask;
int32_t imm16 = imm18 >> 2;
ASSERT(is_int16(imm16));
instr_at_put(pos, instr | (imm16 & kImm16Mask));
} else if (IsLui(instr)) {
Instr instr_lui = instr_at(pos + 0 * Assembler::kInstrSize);
Instr instr_ori = instr_at(pos + 1 * Assembler::kInstrSize);
ASSERT(IsOri(instr_ori));
uint32_t imm = (uint32_t)buffer_ + target_pos;
ASSERT((imm & 3) == 0);
instr_lui &= ~kImm16Mask;
instr_ori &= ~kImm16Mask;
instr_at_put(pos + 0 * Assembler::kInstrSize,
instr_lui | ((imm & kHiMask) >> kLuiShift));
instr_at_put(pos + 1 * Assembler::kInstrSize,
instr_ori | (imm & kImm16Mask));
} else {
uint32_t imm28 = (uint32_t)buffer_ + target_pos;
imm28 &= kImm28Mask;
ASSERT((imm28 & 3) == 0);
instr &= ~kImm26Mask;
uint32_t imm26 = imm28 >> 2;
ASSERT(is_uint26(imm26));
instr_at_put(pos, instr | (imm26 & kImm26Mask));
}
}
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 & ~kImm16Mask) == 0) {
PrintF("value\n");
} else {
PrintF("%d\n", instr);
}
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 valid binding position.
int32_t trampoline_pos = kInvalidSlotPos;
if (L->is_linked() && !trampoline_emitted_) {
unbound_labels_count_--;
next_buffer_check_ += kTrampolineSlotsSize;
}
while (L->is_linked()) {
int32_t fixup_pos = L->pos();
int32_t dist = pos - fixup_pos;
next(L); // Call next before overwriting link with target at fixup_pos.
Instr instr = instr_at(fixup_pos);
if (IsBranch(instr)) {
if (dist > kMaxBranchOffset) {
if (trampoline_pos == kInvalidSlotPos) {
trampoline_pos = get_trampoline_entry(fixup_pos);
CHECK(trampoline_pos != kInvalidSlotPos);
}
ASSERT((trampoline_pos - fixup_pos) <= kMaxBranchOffset);
target_at_put(fixup_pos, trampoline_pos);
fixup_pos = trampoline_pos;
dist = pos - fixup_pos;
}
target_at_put(fixup_pos, pos);
} else {
ASSERT(IsJ(instr) || IsLui(instr));
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::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 == kEndOfChain) {
L->Unuse();
} else {
ASSERT(link >= 0);
L->link_to(link);
}
}
bool Assembler::is_near(Label* L) {
if (L->is_bound()) {
return ((pc_offset() - L->pos()) < kMaxBranchOffset - 4 * kInstrSize);
}
return false;
}
// We have to use a temporary register for things that can be relocated even
// if they can be encoded in the MIPS's 16 bits of immediate-offset instruction
// space. There is no guarantee that the relocated location can be similarly
// encoded.
bool Assembler::MustUseReg(RelocInfo::Mode rmode) {
return rmode != RelocInfo::NONE;
}
void Assembler::GenInstrRegister(Opcode opcode,
Register rs,
Register rt,
Register rd,
uint16_t sa,
SecondaryField func) {
ASSERT(rd.is_valid() && rs.is_valid() && rt.is_valid() && is_uint5(sa));
Instr instr = opcode | (rs.code() << kRsShift) | (rt.code() << kRtShift)
| (rd.code() << kRdShift) | (sa << kSaShift) | func;
emit(instr);
}
void Assembler::GenInstrRegister(Opcode opcode,
Register rs,
Register rt,
uint16_t msb,
uint16_t lsb,
SecondaryField func) {
ASSERT(rs.is_valid() && rt.is_valid() && is_uint5(msb) && is_uint5(lsb));
Instr instr = opcode | (rs.code() << kRsShift) | (rt.code() << kRtShift)
| (msb << kRdShift) | (lsb << kSaShift) | func;
emit(instr);
}
void Assembler::GenInstrRegister(Opcode opcode,
SecondaryField fmt,
FPURegister ft,
FPURegister fs,
FPURegister fd,
SecondaryField func) {
ASSERT(fd.is_valid() && fs.is_valid() && ft.is_valid());
ASSERT(CpuFeatures::IsEnabled(FPU));
Instr instr = opcode | fmt | (ft.code() << kFtShift) | (fs.code() << kFsShift)
| (fd.code() << kFdShift) | func;
emit(instr);
}
void Assembler::GenInstrRegister(Opcode opcode,
SecondaryField fmt,
Register rt,
FPURegister fs,
FPURegister fd,
SecondaryField func) {
ASSERT(fd.is_valid() && fs.is_valid() && rt.is_valid());
ASSERT(CpuFeatures::IsEnabled(FPU));
Instr instr = opcode | fmt | (rt.code() << kRtShift)
| (fs.code() << kFsShift) | (fd.code() << kFdShift) | func;
emit(instr);
}
void Assembler::GenInstrRegister(Opcode opcode,
SecondaryField fmt,
Register rt,
FPUControlRegister fs,
SecondaryField func) {
ASSERT(fs.is_valid() && rt.is_valid());
ASSERT(CpuFeatures::IsEnabled(FPU));
Instr instr =
opcode | fmt | (rt.code() << kRtShift) | (fs.code() << kFsShift) | func;
emit(instr);
}
// Instructions with immediate value.
// Registers are in the order of the instruction encoding, from left to right.
void Assembler::GenInstrImmediate(Opcode opcode,
Register rs,
Register rt,
int32_t j) {
ASSERT(rs.is_valid() && rt.is_valid() && (is_int16(j) || is_uint16(j)));
Instr instr = opcode | (rs.code() << kRsShift) | (rt.code() << kRtShift)
| (j & kImm16Mask);
emit(instr);
}
void Assembler::GenInstrImmediate(Opcode opcode,
Register rs,
SecondaryField SF,
int32_t j) {
ASSERT(rs.is_valid() && (is_int16(j) || is_uint16(j)));
Instr instr = opcode | (rs.code() << kRsShift) | SF | (j & kImm16Mask);
emit(instr);
}
void Assembler::GenInstrImmediate(Opcode opcode,
Register rs,
FPURegister ft,
int32_t j) {
ASSERT(rs.is_valid() && ft.is_valid() && (is_int16(j) || is_uint16(j)));
ASSERT(CpuFeatures::IsEnabled(FPU));
Instr instr = opcode | (rs.code() << kRsShift) | (ft.code() << kFtShift)
| (j & kImm16Mask);
emit(instr);
}
void Assembler::GenInstrJump(Opcode opcode,
uint32_t address) {
BlockTrampolinePoolScope block_trampoline_pool(this);
ASSERT(is_uint26(address));
Instr instr = opcode | address;
emit(instr);
BlockTrampolinePoolFor(1); // For associated delay slot.
}
// Returns the next free trampoline entry.
int32_t Assembler::get_trampoline_entry(int32_t pos) {
int32_t trampoline_entry = kInvalidSlotPos;
if (!internal_trampoline_exception_) {
if (trampoline_.start() > pos) {
trampoline_entry = trampoline_.take_slot();
}
if (kInvalidSlotPos == trampoline_entry) {
internal_trampoline_exception_ = true;
}
}
return trampoline_entry;
}
uint32_t Assembler::jump_address(Label* L) {
int32_t target_pos;
if (L->is_bound()) {
target_pos = L->pos();
} else {
if (L->is_linked()) {
target_pos = L->pos(); // L's link.
L->link_to(pc_offset());
} else {
L->link_to(pc_offset());
return kEndOfJumpChain;
}
}
uint32_t imm = (uint32_t)buffer_ + target_pos;
ASSERT((imm & 3) == 0);
return imm;
}
int32_t Assembler::branch_offset(Label* L, bool jump_elimination_allowed) {
int32_t target_pos;
if (L->is_bound()) {
target_pos = L->pos();
} else {
if (L->is_linked()) {
target_pos = L->pos();
L->link_to(pc_offset());
} else {
L->link_to(pc_offset());
if (!trampoline_emitted_) {
unbound_labels_count_++;
next_buffer_check_ -= kTrampolineSlotsSize;
}
return kEndOfChain;
}
}
int32_t offset = target_pos - (pc_offset() + kBranchPCOffset);
ASSERT((offset & 3) == 0);
ASSERT(is_int16(offset >> 2));
return offset;
}
void Assembler::label_at_put(Label* L, int at_offset) {
int target_pos;
if (L->is_bound()) {
target_pos = L->pos();
instr_at_put(at_offset, target_pos + (Code::kHeaderSize - kHeapObjectTag));
} else {
if (L->is_linked()) {
target_pos = L->pos(); // L's link.
int32_t imm18 = target_pos - at_offset;
ASSERT((imm18 & 3) == 0);
int32_t imm16 = imm18 >> 2;
ASSERT(is_int16(imm16));
instr_at_put(at_offset, (imm16 & kImm16Mask));
} else {
target_pos = kEndOfChain;
instr_at_put(at_offset, 0);
if (!trampoline_emitted_) {
unbound_labels_count_++;
next_buffer_check_ -= kTrampolineSlotsSize;
}
}
L->link_to(at_offset);
}
}
//------- Branch and jump instructions --------
void Assembler::b(int16_t offset) {
beq(zero_reg, zero_reg, offset);
}
void Assembler::bal(int16_t offset) {
positions_recorder()->WriteRecordedPositions();
bgezal(zero_reg, offset);
}
void Assembler::beq(Register rs, Register rt, int16_t offset) {
BlockTrampolinePoolScope block_trampoline_pool(this);
GenInstrImmediate(BEQ, rs, rt, offset);
BlockTrampolinePoolFor(1); // For associated delay slot.
}
void Assembler::bgez(Register rs, int16_t offset) {
BlockTrampolinePoolScope block_trampoline_pool(this);
GenInstrImmediate(REGIMM, rs, BGEZ, offset);
BlockTrampolinePoolFor(1); // For associated delay slot.
}
void Assembler::bgezal(Register rs, int16_t offset) {
BlockTrampolinePoolScope block_trampoline_pool(this);
positions_recorder()->WriteRecordedPositions();
GenInstrImmediate(REGIMM, rs, BGEZAL, offset);
BlockTrampolinePoolFor(1); // For associated delay slot.
}
void Assembler::bgtz(Register rs, int16_t offset) {
BlockTrampolinePoolScope block_trampoline_pool(this);
GenInstrImmediate(BGTZ, rs, zero_reg, offset);
BlockTrampolinePoolFor(1); // For associated delay slot.
}
void Assembler::blez(Register rs, int16_t offset) {
BlockTrampolinePoolScope block_trampoline_pool(this);
GenInstrImmediate(BLEZ, rs, zero_reg, offset);
BlockTrampolinePoolFor(1); // For associated delay slot.
}
void Assembler::bltz(Register rs, int16_t offset) {
BlockTrampolinePoolScope block_trampoline_pool(this);
GenInstrImmediate(REGIMM, rs, BLTZ, offset);
BlockTrampolinePoolFor(1); // For associated delay slot.
}
void Assembler::bltzal(Register rs, int16_t offset) {
BlockTrampolinePoolScope block_trampoline_pool(this);
positions_recorder()->WriteRecordedPositions();
GenInstrImmediate(REGIMM, rs, BLTZAL, offset);
BlockTrampolinePoolFor(1); // For associated delay slot.
}
void Assembler::bne(Register rs, Register rt, int16_t offset) {
BlockTrampolinePoolScope block_trampoline_pool(this);
GenInstrImmediate(BNE, rs, rt, offset);
BlockTrampolinePoolFor(1); // For associated delay slot.
}
void Assembler::j(int32_t target) {
#if DEBUG
// Get pc of delay slot.
uint32_t ipc = reinterpret_cast<uint32_t>(pc_ + 1 * kInstrSize);
bool in_range = ((uint32_t)(ipc^target) >> (kImm26Bits+kImmFieldShift)) == 0;
ASSERT(in_range && ((target & 3) == 0));
#endif
GenInstrJump(J, target >> 2);
}
void Assembler::jr(Register rs) {
BlockTrampolinePoolScope block_trampoline_pool(this);
if (rs.is(ra)) {
positions_recorder()->WriteRecordedPositions();
}
GenInstrRegister(SPECIAL, rs, zero_reg, zero_reg, 0, JR);
BlockTrampolinePoolFor(1); // For associated delay slot.
}
void Assembler::jal(int32_t target) {
#ifdef DEBUG
// Get pc of delay slot.
uint32_t ipc = reinterpret_cast<uint32_t>(pc_ + 1 * kInstrSize);
bool in_range = ((uint32_t)(ipc^target) >> (kImm26Bits+kImmFieldShift)) == 0;
ASSERT(in_range && ((target & 3) == 0));
#endif
positions_recorder()->WriteRecordedPositions();
GenInstrJump(JAL, target >> 2);
}
void Assembler::jalr(Register rs, Register rd) {
BlockTrampolinePoolScope block_trampoline_pool(this);
positions_recorder()->WriteRecordedPositions();
GenInstrRegister(SPECIAL, rs, zero_reg, rd, 0, JALR);
BlockTrampolinePoolFor(1); // For associated delay slot.
}
void Assembler::j_or_jr(int32_t target, Register rs) {
// Get pc of delay slot.
uint32_t ipc = reinterpret_cast<uint32_t>(pc_ + 1 * kInstrSize);
bool in_range = ((uint32_t)(ipc^target) >> (kImm26Bits+kImmFieldShift)) == 0;
if (in_range) {
j(target);
} else {
jr(t9);
}
}
void Assembler::jal_or_jalr(int32_t target, Register rs) {
// Get pc of delay slot.
uint32_t ipc = reinterpret_cast<uint32_t>(pc_ + 1 * kInstrSize);
bool in_range = ((uint32_t)(ipc^target) >> (kImm26Bits+kImmFieldShift)) == 0;
if (in_range) {
jal(target);
} else {
jalr(t9);
}
}
//-------Data-processing-instructions---------
// Arithmetic.
void Assembler::addu(Register rd, Register rs, Register rt) {
GenInstrRegister(SPECIAL, rs, rt, rd, 0, ADDU);
}
void Assembler::addiu(Register rd, Register rs, int32_t j) {
GenInstrImmediate(ADDIU, rs, rd, j);
}
void Assembler::subu(Register rd, Register rs, Register rt) {
GenInstrRegister(SPECIAL, rs, rt, rd, 0, SUBU);
}
void Assembler::mul(Register rd, Register rs, Register rt) {
GenInstrRegister(SPECIAL2, rs, rt, rd, 0, MUL);
}
void Assembler::mult(Register rs, Register rt) {
GenInstrRegister(SPECIAL, rs, rt, zero_reg, 0, MULT);
}
void Assembler::multu(Register rs, Register rt) {
GenInstrRegister(SPECIAL, rs, rt, zero_reg, 0, MULTU);
}
void Assembler::div(Register rs, Register rt) {
GenInstrRegister(SPECIAL, rs, rt, zero_reg, 0, DIV);
}
void Assembler::divu(Register rs, Register rt) {
GenInstrRegister(SPECIAL, rs, rt, zero_reg, 0, DIVU);
}
// Logical.
void Assembler::and_(Register rd, Register rs, Register rt) {
GenInstrRegister(SPECIAL, rs, rt, rd, 0, AND);
}
void Assembler::andi(Register rt, Register rs, int32_t j) {
ASSERT(is_uint16(j));
GenInstrImmediate(ANDI, rs, rt, j);
}
void Assembler::or_(Register rd, Register rs, Register rt) {
GenInstrRegister(SPECIAL, rs, rt, rd, 0, OR);
}
void Assembler::ori(Register rt, Register rs, int32_t j) {
ASSERT(is_uint16(j));
GenInstrImmediate(ORI, rs, rt, j);
}
void Assembler::xor_(Register rd, Register rs, Register rt) {
GenInstrRegister(SPECIAL, rs, rt, rd, 0, XOR);
}
void Assembler::xori(Register rt, Register rs, int32_t j) {
ASSERT(is_uint16(j));
GenInstrImmediate(XORI, rs, rt, j);
}
void Assembler::nor(Register rd, Register rs, Register rt) {
GenInstrRegister(SPECIAL, rs, rt, rd, 0, NOR);
}
// Shifts.
void Assembler::sll(Register rd,
Register rt,
uint16_t sa,
bool coming_from_nop) {
// Don't allow nop instructions in the form sll zero_reg, zero_reg to be
// generated using the sll instruction. They must be generated using
// nop(int/NopMarkerTypes) or MarkCode(int/NopMarkerTypes) pseudo
// instructions.
ASSERT(coming_from_nop || !(rd.is(zero_reg) && rt.is(zero_reg)));
GenInstrRegister(SPECIAL, zero_reg, rt, rd, sa, SLL);
}
void Assembler::sllv(Register rd, Register rt, Register rs) {
GenInstrRegister(SPECIAL, rs, rt, rd, 0, SLLV);
}
void Assembler::srl(Register rd, Register rt, uint16_t sa) {
GenInstrRegister(SPECIAL, zero_reg, rt, rd, sa, SRL);
}
void Assembler::srlv(Register rd, Register rt, Register rs) {
GenInstrRegister(SPECIAL, rs, rt, rd, 0, SRLV);
}
void Assembler::sra(Register rd, Register rt, uint16_t sa) {
GenInstrRegister(SPECIAL, zero_reg, rt, rd, sa, SRA);
}
void Assembler::srav(Register rd, Register rt, Register rs) {
GenInstrRegister(SPECIAL, rs, rt, rd, 0, SRAV);
}
void Assembler::rotr(Register rd, Register rt, uint16_t sa) {
// Should be called via MacroAssembler::Ror.
ASSERT(rd.is_valid() && rt.is_valid() && is_uint5(sa));
ASSERT(kArchVariant == kMips32r2);
Instr instr = SPECIAL | (1 << kRsShift) | (rt.code() << kRtShift)
| (rd.code() << kRdShift) | (sa << kSaShift) | SRL;
emit(instr);
}
void Assembler::rotrv(Register rd, Register rt, Register rs) {
// Should be called via MacroAssembler::Ror.
ASSERT(rd.is_valid() && rt.is_valid() && rs.is_valid() );
ASSERT(kArchVariant == kMips32r2);
Instr instr = SPECIAL | (rs.code() << kRsShift) | (rt.code() << kRtShift)
| (rd.code() << kRdShift) | (1 << kSaShift) | SRLV;
emit(instr);
}
//------------Memory-instructions-------------
// Helper for base-reg + offset, when offset is larger than int16.
void Assembler::LoadRegPlusOffsetToAt(const MemOperand& src) {
ASSERT(!src.rm().is(at));
lui(at, src.offset_ >> kLuiShift);
ori(at, at, src.offset_ & kImm16Mask); // Load 32-bit offset.
addu(at, at, src.rm()); // Add base register.
}
void Assembler::lb(Register rd, const MemOperand& rs) {
if (is_int16(rs.offset_)) {
GenInstrImmediate(LB, rs.rm(), rd, rs.offset_);
} else { // Offset > 16 bits, use multiple instructions to load.
LoadRegPlusOffsetToAt(rs);
GenInstrImmediate(LB, at, rd, 0); // Equiv to lb(rd, MemOperand(at, 0));
}
}
void Assembler::lbu(Register rd, const MemOperand& rs) {
if (is_int16(rs.offset_)) {
GenInstrImmediate(LBU, rs.rm(), rd, rs.offset_);
} else { // Offset > 16 bits, use multiple instructions to load.
LoadRegPlusOffsetToAt(rs);
GenInstrImmediate(LBU, at, rd, 0); // Equiv to lbu(rd, MemOperand(at, 0));
}
}
void Assembler::lh(Register rd, const MemOperand& rs) {
if (is_int16(rs.offset_)) {
GenInstrImmediate(LH, rs.rm(), rd, rs.offset_);
} else { // Offset > 16 bits, use multiple instructions to load.
LoadRegPlusOffsetToAt(rs);
GenInstrImmediate(LH, at, rd, 0); // Equiv to lh(rd, MemOperand(at, 0));
}
}
void Assembler::lhu(Register rd, const MemOperand& rs) {
if (is_int16(rs.offset_)) {
GenInstrImmediate(LHU, rs.rm(), rd, rs.offset_);
} else { // Offset > 16 bits, use multiple instructions to load.
LoadRegPlusOffsetToAt(rs);
GenInstrImmediate(LHU, at, rd, 0); // Equiv to lhu(rd, MemOperand(at, 0));
}
}
void Assembler::lw(Register rd, const MemOperand& rs) {
if (is_int16(rs.offset_)) {
GenInstrImmediate(LW, rs.rm(), rd, rs.offset_);
} else { // Offset > 16 bits, use multiple instructions to load.
LoadRegPlusOffsetToAt(rs);
GenInstrImmediate(LW, at, rd, 0); // Equiv to lw(rd, MemOperand(at, 0));
}
}
void Assembler::lwl(Register rd, const MemOperand& rs) {
GenInstrImmediate(LWL, rs.rm(), rd, rs.offset_);
}
void Assembler::lwr(Register rd, const MemOperand& rs) {
GenInstrImmediate(LWR, rs.rm(), rd, rs.offset_);
}
void Assembler::sb(Register rd, const MemOperand& rs) {
if (is_int16(rs.offset_)) {
GenInstrImmediate(SB, rs.rm(), rd, rs.offset_);
} else { // Offset > 16 bits, use multiple instructions to store.
LoadRegPlusOffsetToAt(rs);
GenInstrImmediate(SB, at, rd, 0); // Equiv to sb(rd, MemOperand(at, 0));
}
}
void Assembler::sh(Register rd, const MemOperand& rs) {
if (is_int16(rs.offset_)) {
GenInstrImmediate(SH, rs.rm(), rd, rs.offset_);
} else { // Offset > 16 bits, use multiple instructions to store.
LoadRegPlusOffsetToAt(rs);
GenInstrImmediate(SH, at, rd, 0); // Equiv to sh(rd, MemOperand(at, 0));
}
}
void Assembler::sw(Register rd, const MemOperand& rs) {
if (is_int16(rs.offset_)) {
GenInstrImmediate(SW, rs.rm(), rd, rs.offset_);
} else { // Offset > 16 bits, use multiple instructions to store.
LoadRegPlusOffsetToAt(rs);
GenInstrImmediate(SW, at, rd, 0); // Equiv to sw(rd, MemOperand(at, 0));
}
}
void Assembler::swl(Register rd, const MemOperand& rs) {
GenInstrImmediate(SWL, rs.rm(), rd, rs.offset_);
}
void Assembler::swr(Register rd, const MemOperand& rs) {
GenInstrImmediate(SWR, rs.rm(), rd, rs.offset_);
}
void Assembler::lui(Register rd, int32_t j) {
ASSERT(is_uint16(j));
GenInstrImmediate(LUI, zero_reg, rd, j);
}
//-------------Misc-instructions--------------
// Break / Trap instructions.
void Assembler::break_(uint32_t code, bool break_as_stop) {
ASSERT((code & ~0xfffff) == 0);
// We need to invalidate breaks that could be stops as well because the
// simulator expects a char pointer after the stop instruction.
// See constants-mips.h for explanation.
ASSERT((break_as_stop &&
code <= kMaxStopCode &&
code > kMaxWatchpointCode) ||
(!break_as_stop &&
(code > kMaxStopCode ||
code <= kMaxWatchpointCode)));
Instr break_instr = SPECIAL | BREAK | (code << 6);
emit(break_instr);
}
void Assembler::stop(const char* msg, uint32_t code) {
ASSERT(code > kMaxWatchpointCode);
ASSERT(code <= kMaxStopCode);
#if defined(V8_HOST_ARCH_MIPS)
break_(0x54321);
#else // V8_HOST_ARCH_MIPS
BlockTrampolinePoolFor(2);
// The Simulator will handle the stop instruction and get the message address.
// On MIPS stop() is just a special kind of break_().
break_(code, true);
emit(reinterpret_cast<Instr>(msg));
#endif
}
void Assembler::tge(Register rs, Register rt, uint16_t code) {
ASSERT(is_uint10(code));
Instr instr = SPECIAL | TGE | rs.code() << kRsShift
| rt.code() << kRtShift | code << 6;
emit(instr);
}
void Assembler::tgeu(Register rs, Register rt, uint16_t code) {
ASSERT(is_uint10(code));
Instr instr = SPECIAL | TGEU | rs.code() << kRsShift
| rt.code() << kRtShift | code << 6;
emit(instr);
}
void Assembler::tlt(Register rs, Register rt, uint16_t code) {
ASSERT(is_uint10(code));
Instr instr =
SPECIAL | TLT | rs.code() << kRsShift | rt.code() << kRtShift | code << 6;
emit(instr);
}
void Assembler::tltu(Register rs, Register rt, uint16_t code) {
ASSERT(is_uint10(code));
Instr instr =
SPECIAL | TLTU | rs.code() << kRsShift
| rt.code() << kRtShift | code << 6;
emit(instr);
}
void Assembler::teq(Register rs, Register rt, uint16_t code) {
ASSERT(is_uint10(code));
Instr instr =
SPECIAL | TEQ | rs.code() << kRsShift | rt.code() << kRtShift | code << 6;
emit(instr);
}
void Assembler::tne(Register rs, Register rt, uint16_t code) {
ASSERT(is_uint10(code));
Instr instr =
SPECIAL | TNE | rs.code() << kRsShift | rt.code() << kRtShift | code << 6;
emit(instr);
}
// Move from HI/LO register.
void Assembler::mfhi(Register rd) {
GenInstrRegister(SPECIAL, zero_reg, zero_reg, rd, 0, MFHI);
}
void Assembler::mflo(Register rd) {
GenInstrRegister(SPECIAL, zero_reg, zero_reg, rd, 0, MFLO);
}
// Set on less than instructions.
void Assembler::slt(Register rd, Register rs, Register rt) {
GenInstrRegister(SPECIAL, rs, rt, rd, 0, SLT);
}
void Assembler::sltu(Register rd, Register rs, Register rt) {
GenInstrRegister(SPECIAL, rs, rt, rd, 0, SLTU);
}
void Assembler::slti(Register rt, Register rs, int32_t j) {
GenInstrImmediate(SLTI, rs, rt, j);
}
void Assembler::sltiu(Register rt, Register rs, int32_t j) {
GenInstrImmediate(SLTIU, rs, rt, j);
}
// Conditional move.
void Assembler::movz(Register rd, Register rs, Register rt) {
GenInstrRegister(SPECIAL, rs, rt, rd, 0, MOVZ);
}
void Assembler::movn(Register rd, Register rs, Register rt) {
GenInstrRegister(SPECIAL, rs, rt, rd, 0, MOVN);
}
void Assembler::movt(Register rd, Register rs, uint16_t cc) {
Register rt;
rt.code_ = (cc & 0x0007) << 2 | 1;
GenInstrRegister(SPECIAL, rs, rt, rd, 0, MOVCI);
}
void Assembler::movf(Register rd, Register rs, uint16_t cc) {
Register rt;
rt.code_ = (cc & 0x0007) << 2 | 0;
GenInstrRegister(SPECIAL, rs, rt, rd, 0, MOVCI);
}
// Bit twiddling.
void Assembler::clz(Register rd, Register rs) {
// Clz instr requires same GPR number in 'rd' and 'rt' fields.
GenInstrRegister(SPECIAL2, rs, rd, rd, 0, CLZ);
}
void Assembler::ins_(Register rt, Register rs, uint16_t pos, uint16_t size) {
// Should be called via MacroAssembler::Ins.
// Ins instr has 'rt' field as dest, and two uint5: msb, lsb.
ASSERT(kArchVariant == kMips32r2);
GenInstrRegister(SPECIAL3, rs, rt, pos + size - 1, pos, INS);
}
void Assembler::ext_(Register rt, Register rs, uint16_t pos, uint16_t size) {
// Should be called via MacroAssembler::Ext.
// Ext instr has 'rt' field as dest, and two uint5: msb, lsb.
ASSERT(kArchVariant == kMips32r2);
GenInstrRegister(SPECIAL3, rs, rt, size - 1, pos, EXT);
}
//--------Coprocessor-instructions----------------
// Load, store, move.
void Assembler::lwc1(FPURegister fd, const MemOperand& src) {
GenInstrImmediate(LWC1, src.rm(), fd, src.offset_);
}
void Assembler::ldc1(FPURegister fd, const MemOperand& src) {
// Workaround for non-8-byte alignment of HeapNumber, convert 64-bit
// load to two 32-bit loads.
GenInstrImmediate(LWC1, src.rm(), fd, src.offset_);
FPURegister nextfpreg;
nextfpreg.setcode(fd.code() + 1);
GenInstrImmediate(LWC1, src.rm(), nextfpreg, src.offset_ + 4);
}
void Assembler::swc1(FPURegister fd, const MemOperand& src) {
GenInstrImmediate(SWC1, src.rm(), fd, src.offset_);
}
void Assembler::sdc1(FPURegister fd, const MemOperand& src) {
// Workaround for non-8-byte alignment of HeapNumber, convert 64-bit
// store to two 32-bit stores.
GenInstrImmediate(SWC1, src.rm(), fd, src.offset_);
FPURegister nextfpreg;
nextfpreg.setcode(fd.code() + 1);
GenInstrImmediate(SWC1, src.rm(), nextfpreg, src.offset_ + 4);
}
void Assembler::mtc1(Register rt, FPURegister fs) {
GenInstrRegister(COP1, MTC1, rt, fs, f0);
}
void Assembler::mfc1(Register rt, FPURegister fs) {
GenInstrRegister(COP1, MFC1, rt, fs, f0);
}
void Assembler::ctc1(Register rt, FPUControlRegister fs) {
GenInstrRegister(COP1, CTC1, rt, fs);
}
void Assembler::cfc1(Register rt, FPUControlRegister fs) {
GenInstrRegister(COP1, CFC1, rt, fs);
}
void Assembler::DoubleAsTwoUInt32(double d, uint32_t* lo, uint32_t* hi) {
uint64_t i;
memcpy(&i, &d, 8);
*lo = i & 0xffffffff;
*hi = i >> 32;
}
// Arithmetic.
void Assembler::add_d(FPURegister fd, FPURegister fs, FPURegister ft) {
GenInstrRegister(COP1, D, ft, fs, fd, ADD_D);
}
void Assembler::sub_d(FPURegister fd, FPURegister fs, FPURegister ft) {
GenInstrRegister(COP1, D, ft, fs, fd, SUB_D);
}
void Assembler::mul_d(FPURegister fd, FPURegister fs, FPURegister ft) {
GenInstrRegister(COP1, D, ft, fs, fd, MUL_D);
}
void Assembler::div_d(FPURegister fd, FPURegister fs, FPURegister ft) {
GenInstrRegister(COP1, D, ft, fs, fd, DIV_D);
}
void Assembler::abs_d(FPURegister fd, FPURegister fs) {
GenInstrRegister(COP1, D, f0, fs, fd, ABS_D);
}
void Assembler::mov_d(FPURegister fd, FPURegister fs) {
GenInstrRegister(COP1, D, f0, fs, fd, MOV_D);
}
void Assembler::neg_d(FPURegister fd, FPURegister fs) {
GenInstrRegister(COP1, D, f0, fs, fd, NEG_D);
}
void Assembler::sqrt_d(FPURegister fd, FPURegister fs) {
GenInstrRegister(COP1, D, f0, fs, fd, SQRT_D);
}
// Conversions.
void Assembler::cvt_w_s(FPURegister fd, FPURegister fs) {
GenInstrRegister(COP1, S, f0, fs, fd, CVT_W_S);
}
void Assembler::cvt_w_d(FPURegister fd, FPURegister fs) {
GenInstrRegister(COP1, D, f0, fs, fd, CVT_W_D);
}
void Assembler::trunc_w_s(FPURegister fd, FPURegister fs) {
GenInstrRegister(COP1, S, f0, fs, fd, TRUNC_W_S);
}
void Assembler::trunc_w_d(FPURegister fd, FPURegister fs) {
GenInstrRegister(COP1, D, f0, fs, fd, TRUNC_W_D);
}
void Assembler::round_w_s(FPURegister fd, FPURegister fs) {
GenInstrRegister(COP1, S, f0, fs, fd, ROUND_W_S);
}
void Assembler::round_w_d(FPURegister fd, FPURegister fs) {
GenInstrRegister(COP1, D, f0, fs, fd, ROUND_W_D);
}
void Assembler::floor_w_s(FPURegister fd, FPURegister fs) {
GenInstrRegister(COP1, S, f0, fs, fd, FLOOR_W_S);
}
void Assembler::floor_w_d(FPURegister fd, FPURegister fs) {
GenInstrRegister(COP1, D, f0, fs, fd, FLOOR_W_D);
}
void Assembler::ceil_w_s(FPURegister fd, FPURegister fs) {
GenInstrRegister(COP1, S, f0, fs, fd, CEIL_W_S);
}
void Assembler::ceil_w_d(FPURegister fd, FPURegister fs) {
GenInstrRegister(COP1, D, f0, fs, fd, CEIL_W_D);
}
void Assembler::cvt_l_s(FPURegister fd, FPURegister fs) {
ASSERT(kArchVariant == kMips32r2);
GenInstrRegister(COP1, S, f0, fs, fd, CVT_L_S);
}
void Assembler::cvt_l_d(FPURegister fd, FPURegister fs) {
ASSERT(kArchVariant == kMips32r2);
GenInstrRegister(COP1, D, f0, fs, fd, CVT_L_D);
}
void Assembler::trunc_l_s(FPURegister fd, FPURegister fs) {
ASSERT(kArchVariant == kMips32r2);
GenInstrRegister(COP1, S, f0, fs, fd, TRUNC_L_S);
}
void Assembler::trunc_l_d(FPURegister fd, FPURegister fs) {
ASSERT(kArchVariant == kMips32r2);
GenInstrRegister(COP1, D, f0, fs, fd, TRUNC_L_D);
}
void Assembler::round_l_s(FPURegister fd, FPURegister fs) {
GenInstrRegister(COP1, S, f0, fs, fd, ROUND_L_S);
}
void Assembler::round_l_d(FPURegister fd, FPURegister fs) {
GenInstrRegister(COP1, D, f0, fs, fd, ROUND_L_D);
}
void Assembler::floor_l_s(FPURegister fd, FPURegister fs) {
GenInstrRegister(COP1, S, f0, fs, fd, FLOOR_L_S);
}
void Assembler::floor_l_d(FPURegister fd, FPURegister fs) {
GenInstrRegister(COP1, D, f0, fs, fd, FLOOR_L_D);
}
void Assembler::ceil_l_s(FPURegister fd, FPURegister fs) {
GenInstrRegister(COP1, S, f0, fs, fd, CEIL_L_S);
}
void Assembler::ceil_l_d(FPURegister fd, FPURegister fs) {
GenInstrRegister(COP1, D, f0, fs, fd, CEIL_L_D);
}
void Assembler::cvt_s_w(FPURegister fd, FPURegister fs) {
GenInstrRegister(COP1, W, f0, fs, fd, CVT_S_W);
}
void Assembler::cvt_s_l(FPURegister fd, FPURegister fs) {
ASSERT(kArchVariant == kMips32r2);
GenInstrRegister(COP1, L, f0, fs, fd, CVT_S_L);
}
void Assembler::cvt_s_d(FPURegister fd, FPURegister fs) {
GenInstrRegister(COP1, D, f0, fs, fd, CVT_S_D);
}
void Assembler::cvt_d_w(FPURegister fd, FPURegister fs) {
GenInstrRegister(COP1, W, f0, fs, fd, CVT_D_W);
}
void Assembler::cvt_d_l(FPURegister fd, FPURegister fs) {
ASSERT(kArchVariant == kMips32r2);
GenInstrRegister(COP1, L, f0, fs, fd, CVT_D_L);
}
void Assembler::cvt_d_s(FPURegister fd, FPURegister fs) {
GenInstrRegister(COP1, S, f0, fs, fd, CVT_D_S);
}
// Conditions.
void Assembler::c(FPUCondition cond, SecondaryField fmt,
FPURegister fs, FPURegister ft, uint16_t cc) {
ASSERT(CpuFeatures::IsEnabled(FPU));
ASSERT(is_uint3(cc));
ASSERT((fmt & ~(31 << kRsShift)) == 0);
Instr instr = COP1 | fmt | ft.code() << 16 | fs.code() << kFsShift
| cc << 8 | 3 << 4 | cond;
emit(instr);
}
void Assembler::fcmp(FPURegister src1, const double src2,
FPUCondition cond) {
ASSERT(CpuFeatures::IsEnabled(FPU));
ASSERT(src2 == 0.0);
mtc1(zero_reg, f14);
cvt_d_w(f14, f14);
c(cond, D, src1, f14, 0);
}
void Assembler::bc1f(int16_t offset, uint16_t cc) {
ASSERT(CpuFeatures::IsEnabled(FPU));
ASSERT(is_uint3(cc));
Instr instr = COP1 | BC1 | cc << 18 | 0 << 16 | (offset & kImm16Mask);
emit(instr);
}
void Assembler::bc1t(int16_t offset, uint16_t cc) {
ASSERT(CpuFeatures::IsEnabled(FPU));
ASSERT(is_uint3(cc));
Instr instr = COP1 | BC1 | cc << 18 | 1 << 16 | (offset & kImm16Mask);
emit(instr);
}
// 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));
}
}
int Assembler::RelocateInternalReference(byte* pc, intptr_t pc_delta) {
Instr instr = instr_at(pc);
ASSERT(IsJ(instr) || IsLui(instr));
if (IsLui(instr)) {
Instr instr_lui = instr_at(pc + 0 * Assembler::kInstrSize);
Instr instr_ori = instr_at(pc + 1 * Assembler::kInstrSize);
ASSERT(IsOri(instr_ori));
int32_t imm = (instr_lui & static_cast<int32_t>(kImm16Mask)) << kLuiShift;
imm |= (instr_ori & static_cast<int32_t>(kImm16Mask));
if (imm == kEndOfJumpChain) {
return 0; // Number of instructions patched.
}
imm += pc_delta;
ASSERT((imm & 3) == 0);
instr_lui &= ~kImm16Mask;
instr_ori &= ~kImm16Mask;
instr_at_put(pc + 0 * Assembler::kInstrSize,
instr_lui | ((imm >> kLuiShift) & kImm16Mask));
instr_at_put(pc + 1 * Assembler::kInstrSize,
instr_ori | (imm & kImm16Mask));
return 2; // Number of instructions patched.
} else {
uint32_t imm28 = (instr & static_cast<int32_t>(kImm26Mask)) << 2;
if ((int32_t)imm28 == kEndOfJumpChain) {
return 0; // Number of instructions patched.
}
imm28 += pc_delta;
imm28 &= kImm28Mask;
ASSERT((imm28 & 3) == 0);
instr &= ~kImm26Mask;
uint32_t imm26 = imm28 >> 2;
ASSERT(is_uint26(imm26));
instr_at_put(pc, instr | (imm26 & kImm26Mask));
return 1; // Number of instructions patched.
}
}
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.
// Set up 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);
// Relocate runtime entries.
for (RelocIterator it(desc); !it.done(); it.next()) {
RelocInfo::Mode rmode = it.rinfo()->rmode();
if (rmode == RelocInfo::INTERNAL_REFERENCE) {
byte* p = reinterpret_cast<byte*>(it.rinfo()->pc());
RelocateInternalReference(p, pc_delta);
}
}
ASSERT(!overflow());
}
void Assembler::db(uint8_t data) {
CheckBuffer();
*reinterpret_cast<uint8_t*>(pc_) = data;
pc_ += sizeof(uint8_t);
}
void Assembler::dd(uint32_t data) {
CheckBuffer();
*reinterpret_cast<uint32_t*>(pc_) = data;
pc_ += sizeof(uint32_t);
}
void Assembler::RecordRelocInfo(RelocInfo::Mode rmode, intptr_t data) {
// We do not try to reuse pool constants.
RelocInfo rinfo(pc_, rmode, data, NULL);
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.
}
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() && !emit_debug_code()) {
return;
}
}
ASSERT(buffer_space() >= kMaxRelocSize); // Too late to grow buffer here.
if (rmode == RelocInfo::CODE_TARGET_WITH_ID) {
RelocInfo reloc_info_with_ast_id(pc_,
rmode,
RecordedAstId().ToInt(),
NULL);
ClearRecordedAstId();
reloc_info_writer.Write(&reloc_info_with_ast_id);
} else {
reloc_info_writer.Write(&rinfo);
}
}
}
void Assembler::BlockTrampolinePoolFor(int instructions) {
BlockTrampolinePoolBefore(pc_offset() + instructions * kInstrSize);
}
void Assembler::CheckTrampolinePool() {
// Some small sequences of instructions must not be broken up by the
// insertion of a trampoline pool; such sequences are protected by setting
// either trampoline_pool_blocked_nesting_ or no_trampoline_pool_before_,
// which are both checked here. Also, recursive calls to CheckTrampolinePool
// are blocked by trampoline_pool_blocked_nesting_.
if ((trampoline_pool_blocked_nesting_ > 0) ||
(pc_offset() < no_trampoline_pool_before_)) {
// Emission is currently blocked; make sure we try again as soon as
// possible.
if (trampoline_pool_blocked_nesting_ > 0) {
next_buffer_check_ = pc_offset() + kInstrSize;
} else {
next_buffer_check_ = no_trampoline_pool_before_;
}
return;
}
ASSERT(!trampoline_emitted_);
ASSERT(unbound_labels_count_ >= 0);
if (unbound_labels_count_ > 0) {
// First we emit jump (2 instructions), then we emit trampoline pool.
{ BlockTrampolinePoolScope block_trampoline_pool(this);
Label after_pool;
b(&after_pool);
nop();
int pool_start = pc_offset();
for (int i = 0; i < unbound_labels_count_; i++) {
uint32_t imm32;
imm32 = jump_address(&after_pool);
{ BlockGrowBufferScope block_buf_growth(this);
// Buffer growth (and relocation) must be blocked for internal
// references until associated instructions are emitted and available
// to be patched.
RecordRelocInfo(RelocInfo::INTERNAL_REFERENCE);
lui(at, (imm32 & kHiMask) >> kLuiShift);
ori(at, at, (imm32 & kImm16Mask));
}
jr(at);
nop();
}
bind(&after_pool);
trampoline_ = Trampoline(pool_start, unbound_labels_count_);
trampoline_emitted_ = true;
// As we are only going to emit trampoline once, we need to prevent any
// further emission.
next_buffer_check_ = kMaxInt;
}
} else {
// Number of branches to unbound label at this point is zero, so we can
// move next buffer check to maximum.
next_buffer_check_ = pc_offset() +
kMaxBranchOffset - kTrampolineSlotsSize * 16;
}
return;
}
Address Assembler::target_address_at(Address pc) {
Instr instr1 = instr_at(pc);
Instr instr2 = instr_at(pc + kInstrSize);
// Interpret 2 instructions generated by li: lui/ori
if ((GetOpcodeField(instr1) == LUI) && (GetOpcodeField(instr2) == ORI)) {
// Assemble the 32 bit value.
return reinterpret_cast<Address>(
(GetImmediate16(instr1) << 16) | GetImmediate16(instr2));
}
// We should never get here, force a bad address if we do.
UNREACHABLE();
return (Address)0x0;
}
// MIPS and ia32 use opposite encoding for qNaN and sNaN, such that ia32
// qNaN is a MIPS sNaN, and ia32 sNaN is MIPS qNaN. If running from a heap
// snapshot generated on ia32, the resulting MIPS sNaN must be quieted.
// OS::nan_value() returns a qNaN.
void Assembler::QuietNaN(HeapObject* object) {
HeapNumber::cast(object)->set_value(OS::nan_value());
}
// On Mips, a target address is stored in a lui/ori instruction pair, each
// of which load 16 bits of the 32-bit address to a register.
// Patching the address must replace both instr, and flush the i-cache.
//
// There is an optimization below, which emits a nop when the address
// fits in just 16 bits. This is unlikely to help, and should be benchmarked,
// and possibly removed.
void Assembler::set_target_address_at(Address pc, Address target) {
Instr instr2 = instr_at(pc + kInstrSize);
uint32_t rt_code = GetRtField(instr2);
uint32_t* p = reinterpret_cast<uint32_t*>(pc);
uint32_t itarget = reinterpret_cast<uint32_t>(target);
#ifdef DEBUG
// Check we have the result from a li macro-instruction, using instr pair.
Instr instr1 = instr_at(pc);
CHECK((GetOpcodeField(instr1) == LUI && GetOpcodeField(instr2) == ORI));
#endif
// Must use 2 instructions to insure patchable code => just use lui and ori.
// lui rt, upper-16.
// ori rt rt, lower-16.
*p = LUI | rt_code | ((itarget & kHiMask) >> kLuiShift);
*(p+1) = ORI | rt_code | (rt_code << 5) | (itarget & kImm16Mask);
// The following code is an optimization for the common case of Call()
// or Jump() which is load to register, and jump through register:
// li(t9, address); jalr(t9) (or jr(t9)).
// If the destination address is in the same 256 MB page as the call, it
// is faster to do a direct jal, or j, rather than jump thru register, since
// that lets the cpu pipeline prefetch the target address. However each
// time the address above is patched, we have to patch the direct jal/j
// instruction, as well as possibly revert to jalr/jr if we now cross a
// 256 MB page. Note that with the jal/j instructions, we do not need to
// load the register, but that code is left, since it makes it easy to
// revert this process. A further optimization could try replacing the
// li sequence with nops.
// This optimization can only be applied if the rt-code from instr2 is the
// register used for the jalr/jr. Finally, we have to skip 'jr ra', which is
// mips return. Occasionally this lands after an li().
Instr instr3 = instr_at(pc + 2 * kInstrSize);
uint32_t ipc = reinterpret_cast<uint32_t>(pc + 3 * kInstrSize);
bool in_range =
((uint32_t)(ipc ^ itarget) >> (kImm26Bits + kImmFieldShift)) == 0;
uint32_t target_field = (uint32_t)(itarget & kJumpAddrMask) >> kImmFieldShift;
bool patched_jump = false;
#ifndef ALLOW_JAL_IN_BOUNDARY_REGION
// This is a workaround to the 24k core E156 bug (affect some 34k cores also).
// Since the excluded space is only 64KB out of 256MB (0.02 %), we will just
// apply this workaround for all cores so we don't have to identify the core.
if (in_range) {
// The 24k core E156 bug has some very specific requirements, we only check
// the most simple one: if the address of the delay slot instruction is in
// the first or last 32 KB of the 256 MB segment.
uint32_t segment_mask = ((256 * MB) - 1) ^ ((32 * KB) - 1);
uint32_t ipc_segment_addr = ipc & segment_mask;
if (ipc_segment_addr == 0 || ipc_segment_addr == segment_mask)
in_range = false;
}
#endif
if (IsJalr(instr3)) {
// Try to convert JALR to JAL.
if (in_range && GetRt(instr2) == GetRs(instr3)) {
*(p+2) = JAL | target_field;
patched_jump = true;
}
} else if (IsJr(instr3)) {
// Try to convert JR to J, skip returns (jr ra).
bool is_ret = static_cast<int>(GetRs(instr3)) == ra.code();
if (in_range && !is_ret && GetRt(instr2) == GetRs(instr3)) {
*(p+2) = J | target_field;
patched_jump = true;
}
} else if (IsJal(instr3)) {
if (in_range) {
// We are patching an already converted JAL.
*(p+2) = JAL | target_field;
} else {
// Patch JAL, but out of range, revert to JALR.
// JALR rs reg is the rt reg specified in the ORI instruction.
uint32_t rs_field = GetRt(instr2) << kRsShift;
uint32_t rd_field = ra.code() << kRdShift; // Return-address (ra) reg.
*(p+2) = SPECIAL | rs_field | rd_field | JALR;
}
patched_jump = true;
} else if (IsJ(instr3)) {
if (in_range) {
// We are patching an already converted J (jump).
*(p+2) = J | target_field;
} else {
// Trying patch J, but out of range, just go back to JR.
// JR 'rs' reg is the 'rt' reg specified in the ORI instruction (instr2).
uint32_t rs_field = GetRt(instr2) << kRsShift;
*(p+2) = SPECIAL | rs_field | JR;
}
patched_jump = true;
}
CPU::FlushICache(pc, (patched_jump ? 3 : 2) * sizeof(int32_t));
}
void Assembler::JumpLabelToJumpRegister(Address pc) {
// Address pc points to lui/ori instructions.
// Jump to label may follow at pc + 2 * kInstrSize.
uint32_t* p = reinterpret_cast<uint32_t*>(pc);
#ifdef DEBUG
Instr instr1 = instr_at(pc);
#endif
Instr instr2 = instr_at(pc + 1 * kInstrSize);
Instr instr3 = instr_at(pc + 2 * kInstrSize);
bool patched = false;
if (IsJal(instr3)) {
ASSERT(GetOpcodeField(instr1) == LUI);
ASSERT(GetOpcodeField(instr2) == ORI);
uint32_t rs_field = GetRt(instr2) << kRsShift;
uint32_t rd_field = ra.code() << kRdShift; // Return-address (ra) reg.
*(p+2) = SPECIAL | rs_field | rd_field | JALR;
patched = true;
} else if (IsJ(instr3)) {
ASSERT(GetOpcodeField(instr1) == LUI);
ASSERT(GetOpcodeField(instr2) == ORI);
uint32_t rs_field = GetRt(instr2) << kRsShift;
*(p+2) = SPECIAL | rs_field | JR;
patched = true;
}
if (patched) {
CPU::FlushICache(pc+2, sizeof(Address));
}
}
} } // namespace v8::internal
#endif // V8_TARGET_ARCH_MIPS
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