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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.
// A light-weight ARM Assembler
// Generates user mode instructions for the ARM architecture up to version 5
#ifndef V8_ARM_ASSEMBLER_ARM_H_
#define V8_ARM_ASSEMBLER_ARM_H_
#include <stdio.h>
#include <vector>
#include "src/arm/constants-arm.h"
#include "src/arm/register-arm.h"
#include "src/codegen/assembler.h"
#include "src/codegen/constant-pool.h"
#include "src/numbers/double.h"
#include "src/utils/boxed-float.h"
namespace v8 {
namespace internal {
class SafepointTableBuilder;
// Coprocessor number
enum Coprocessor {
p0 = 0,
p1 = 1,
p2 = 2,
p3 = 3,
p4 = 4,
p5 = 5,
p6 = 6,
p7 = 7,
p8 = 8,
p9 = 9,
p10 = 10,
p11 = 11,
p12 = 12,
p13 = 13,
p14 = 14,
p15 = 15
};
// -----------------------------------------------------------------------------
// Machine instruction Operands
// Class Operand represents a shifter operand in data processing instructions
class V8_EXPORT_PRIVATE Operand {
public:
// immediate
V8_INLINE explicit Operand(int32_t immediate,
RelocInfo::Mode rmode = RelocInfo::NONE)
: rmode_(rmode) {
value_.immediate = immediate;
}
V8_INLINE static Operand Zero();
V8_INLINE explicit Operand(const ExternalReference& f);
explicit Operand(Handle<HeapObject> handle);
V8_INLINE explicit Operand(Smi value);
// rm
V8_INLINE explicit Operand(Register rm);
// rm <shift_op> shift_imm
explicit Operand(Register rm, ShiftOp shift_op, int shift_imm);
V8_INLINE static Operand SmiUntag(Register rm) {
return Operand(rm, ASR, kSmiTagSize);
}
V8_INLINE static Operand PointerOffsetFromSmiKey(Register key) {
STATIC_ASSERT(kSmiTag == 0 && kSmiTagSize < kPointerSizeLog2);
return Operand(key, LSL, kPointerSizeLog2 - kSmiTagSize);
}
V8_INLINE static Operand DoubleOffsetFromSmiKey(Register key) {
STATIC_ASSERT(kSmiTag == 0 && kSmiTagSize < kDoubleSizeLog2);
return Operand(key, LSL, kDoubleSizeLog2 - kSmiTagSize);
}
// rm <shift_op> rs
explicit Operand(Register rm, ShiftOp shift_op, Register rs);
static Operand EmbeddedNumber(double number); // Smi or HeapNumber.
static Operand EmbeddedStringConstant(const StringConstantBase* str);
// Return true if this is a register operand.
bool IsRegister() const {
return rm_.is_valid() && rs_ == no_reg && shift_op_ == LSL &&
shift_imm_ == 0;
}
// Return true if this is a register operand shifted with an immediate.
bool IsImmediateShiftedRegister() const {
return rm_.is_valid() && !rs_.is_valid();
}
// Return true if this is a register operand shifted with a register.
bool IsRegisterShiftedRegister() const {
return rm_.is_valid() && rs_.is_valid();
}
// Return the number of actual instructions required to implement the given
// instruction for this particular operand. This can be a single instruction,
// if no load into a scratch register is necessary, or anything between 2 and
// 4 instructions when we need to load from the constant pool (depending upon
// whether the constant pool entry is in the small or extended section). If
// the instruction this operand is used for is a MOV or MVN instruction the
// actual instruction to use is required for this calculation. For other
// instructions instr is ignored.
//
// The value returned is only valid as long as no entries are added to the
// constant pool between this call and the actual instruction being emitted.
int InstructionsRequired(const Assembler* assembler, Instr instr = 0) const;
bool MustOutputRelocInfo(const Assembler* assembler) const;
inline int32_t immediate() const {
DCHECK(IsImmediate());
DCHECK(!IsHeapObjectRequest());
return value_.immediate;
}
bool IsImmediate() const {
return !rm_.is_valid();
}
HeapObjectRequest heap_object_request() const {
DCHECK(IsHeapObjectRequest());
return value_.heap_object_request;
}
bool IsHeapObjectRequest() const {
DCHECK_IMPLIES(is_heap_object_request_, IsImmediate());
DCHECK_IMPLIES(is_heap_object_request_,
rmode_ == RelocInfo::FULL_EMBEDDED_OBJECT ||
rmode_ == RelocInfo::CODE_TARGET);
return is_heap_object_request_;
}
Register rm() const { return rm_; }
Register rs() const { return rs_; }
ShiftOp shift_op() const { return shift_op_; }
private:
Register rm_ = no_reg;
Register rs_ = no_reg;
ShiftOp shift_op_;
int shift_imm_; // valid if rm_ != no_reg && rs_ == no_reg
union Value {
Value() {}
HeapObjectRequest heap_object_request; // if is_heap_object_request_
int32_t immediate; // otherwise
} value_; // valid if rm_ == no_reg
bool is_heap_object_request_ = false;
RelocInfo::Mode rmode_;
friend class Assembler;
};
// Class MemOperand represents a memory operand in load and store instructions
class V8_EXPORT_PRIVATE MemOperand {
public:
// [rn +/- offset] Offset/NegOffset
// [rn +/- offset]! PreIndex/NegPreIndex
// [rn], +/- offset PostIndex/NegPostIndex
// offset is any signed 32-bit value; offset is first loaded to a scratch
// register if it does not fit the addressing mode (12-bit unsigned and sign
// bit)
explicit MemOperand(Register rn, int32_t offset = 0, AddrMode am = Offset);
// [rn +/- rm] Offset/NegOffset
// [rn +/- rm]! PreIndex/NegPreIndex
// [rn], +/- rm PostIndex/NegPostIndex
explicit MemOperand(Register rn, Register rm, AddrMode am = Offset);
// [rn +/- rm <shift_op> shift_imm] Offset/NegOffset
// [rn +/- rm <shift_op> shift_imm]! PreIndex/NegPreIndex
// [rn], +/- rm <shift_op> shift_imm PostIndex/NegPostIndex
explicit MemOperand(Register rn, Register rm,
ShiftOp shift_op, int shift_imm, AddrMode am = Offset);
V8_INLINE static MemOperand PointerAddressFromSmiKey(Register array,
Register key,
AddrMode am = Offset) {
STATIC_ASSERT(kSmiTag == 0 && kSmiTagSize < kPointerSizeLog2);
return MemOperand(array, key, LSL, kPointerSizeLog2 - kSmiTagSize, am);
}
void set_offset(int32_t offset) {
DCHECK(rm_ == no_reg);
offset_ = offset;
}
uint32_t offset() const {
DCHECK(rm_ == no_reg);
return offset_;
}
Register rn() const { return rn_; }
Register rm() const { return rm_; }
AddrMode am() const { return am_; }
bool OffsetIsUint12Encodable() const {
return offset_ >= 0 ? is_uint12(offset_) : is_uint12(-offset_);
}
private:
Register rn_; // base
Register rm_; // register offset
int32_t offset_; // valid if rm_ == no_reg
ShiftOp shift_op_;
int shift_imm_; // valid if rm_ != no_reg && rs_ == no_reg
AddrMode am_; // bits P, U, and W
friend class Assembler;
};
// Class NeonMemOperand represents a memory operand in load and
// store NEON instructions
class V8_EXPORT_PRIVATE NeonMemOperand {
public:
// [rn {:align}] Offset
// [rn {:align}]! PostIndex
explicit NeonMemOperand(Register rn, AddrMode am = Offset, int align = 0);
// [rn {:align}], rm PostIndex
explicit NeonMemOperand(Register rn, Register rm, int align = 0);
Register rn() const { return rn_; }
Register rm() const { return rm_; }
int align() const { return align_; }
private:
void SetAlignment(int align);
Register rn_; // base
Register rm_; // register increment
int align_;
};
// Class NeonListOperand represents a list of NEON registers
class NeonListOperand {
public:
explicit NeonListOperand(DoubleRegister base, int register_count = 1)
: base_(base), register_count_(register_count) {}
explicit NeonListOperand(QwNeonRegister q_reg)
: base_(q_reg.low()), register_count_(2) {}
DoubleRegister base() const { return base_; }
int register_count() { return register_count_; }
int length() const { return register_count_ - 1; }
NeonListType type() const {
switch (register_count_) {
default: UNREACHABLE();
// Fall through.
case 1: return nlt_1;
case 2: return nlt_2;
case 3: return nlt_3;
case 4: return nlt_4;
}
}
private:
DoubleRegister base_;
int register_count_;
};
class V8_EXPORT_PRIVATE Assembler : public AssemblerBase {
public:
// Create an assembler. Instructions and relocation information are emitted
// into a buffer, with the instructions starting from the beginning and the
// relocation information starting from the end of the buffer. See CodeDesc
// for a detailed comment on the layout (globals.h).
//
// If the provided buffer is nullptr, the assembler allocates and grows its
// own buffer. Otherwise it takes ownership of the provided buffer.
explicit Assembler(const AssemblerOptions&,
std::unique_ptr<AssemblerBuffer> = {});
virtual ~Assembler();
virtual void AbortedCodeGeneration() {
pending_32_bit_constants_.clear();
}
// GetCode emits any pending (non-emitted) code and fills the descriptor desc.
static constexpr int kNoHandlerTable = 0;
static constexpr SafepointTableBuilder* kNoSafepointTable = nullptr;
void GetCode(Isolate* isolate, CodeDesc* desc,
SafepointTableBuilder* safepoint_table_builder,
int handler_table_offset);
// Convenience wrapper for code without safepoint or handler tables.
void GetCode(Isolate* isolate, CodeDesc* desc) {
GetCode(isolate, desc, kNoSafepointTable, kNoHandlerTable);
}
// Label operations & relative jumps (PPUM Appendix D)
//
// Takes a branch opcode (cc) and a label (L) and generates
// either a backward branch or a forward branch and links it
// to the label fixup chain. Usage:
//
// Label L; // unbound label
// j(cc, &L); // forward branch to unbound label
// bind(&L); // bind label to the current pc
// j(cc, &L); // backward branch to bound label
// bind(&L); // illegal: a label may be bound only once
//
// Note: The same Label can be used for forward and backward branches
// but it may be bound only once.
void bind(Label* L); // binds an unbound label L to the current code position
// Returns the branch offset to the given label from the current code position
// Links the label to the current position if it is still unbound
// Manages the jump elimination optimization if the second parameter is true.
int branch_offset(Label* L);
// Returns true if the given pc address is the start of a constant pool load
// instruction sequence.
V8_INLINE static bool is_constant_pool_load(Address pc);
// Return the address in the constant pool of the code target address used by
// the branch/call instruction at pc, or the object in a mov.
V8_INLINE static Address constant_pool_entry_address(Address pc,
Address constant_pool);
// Read/Modify the code target address in the branch/call instruction at pc.
// The isolate argument is unused (and may be nullptr) when skipping flushing.
V8_INLINE static Address target_address_at(Address pc, Address constant_pool);
V8_INLINE static void set_target_address_at(
Address pc, Address constant_pool, Address target,
ICacheFlushMode icache_flush_mode = FLUSH_ICACHE_IF_NEEDED);
// This sets the branch destination (which is in the constant pool on ARM).
// This is for calls and branches within generated code.
inline static void deserialization_set_special_target_at(
Address constant_pool_entry, Code code, Address target);
// Get the size of the special target encoded at 'location'.
inline static int deserialization_special_target_size(Address location);
// This sets the internal reference at the pc.
inline static void deserialization_set_target_internal_reference_at(
Address pc, Address target,
RelocInfo::Mode mode = RelocInfo::INTERNAL_REFERENCE);
// Here we are patching the address in the constant pool, not the actual call
// instruction. The address in the constant pool is the same size as a
// pointer.
static constexpr int kSpecialTargetSize = kPointerSize;
RegList* GetScratchRegisterList() { return &scratch_register_list_; }
VfpRegList* GetScratchVfpRegisterList() {
return &scratch_vfp_register_list_;
}
// ---------------------------------------------------------------------------
// Code generation
// Insert the smallest number of nop instructions
// possible to align the pc offset to a multiple
// of m. m must be a power of 2 (>= 4).
void Align(int m);
// Insert the smallest number of zero bytes possible to align the pc offset
// to a mulitple of m. m must be a power of 2 (>= 2).
void DataAlign(int m);
// Aligns code to something that's optimal for a jump target for the platform.
void CodeTargetAlign();
// Branch instructions
void b(int branch_offset, Condition cond = al,
RelocInfo::Mode rmode = RelocInfo::NONE);
void bl(int branch_offset, Condition cond = al,
RelocInfo::Mode rmode = RelocInfo::NONE);
void blx(int branch_offset); // v5 and above
void blx(Register target, Condition cond = al); // v5 and above
void bx(Register target, Condition cond = al); // v5 and above, plus v4t
// Convenience branch instructions using labels
void b(Label* L, Condition cond = al);
void b(Condition cond, Label* L) { b(L, cond); }
void bl(Label* L, Condition cond = al);
void bl(Condition cond, Label* L) { bl(L, cond); }
void blx(Label* L); // v5 and above
// Data-processing instructions
void and_(Register dst, Register src1, const Operand& src2,
SBit s = LeaveCC, Condition cond = al);
void and_(Register dst, Register src1, Register src2, SBit s = LeaveCC,
Condition cond = al);
void eor(Register dst, Register src1, const Operand& src2,
SBit s = LeaveCC, Condition cond = al);
void eor(Register dst, Register src1, Register src2, SBit s = LeaveCC,
Condition cond = al);
void sub(Register dst, Register src1, const Operand& src2,
SBit s = LeaveCC, Condition cond = al);
void sub(Register dst, Register src1, Register src2,
SBit s = LeaveCC, Condition cond = al);
void rsb(Register dst, Register src1, const Operand& src2,
SBit s = LeaveCC, Condition cond = al);
void add(Register dst, Register src1, const Operand& src2,
SBit s = LeaveCC, Condition cond = al);
void add(Register dst, Register src1, Register src2,
SBit s = LeaveCC, Condition cond = al);
void adc(Register dst, Register src1, const Operand& src2,
SBit s = LeaveCC, Condition cond = al);
void sbc(Register dst, Register src1, const Operand& src2,
SBit s = LeaveCC, Condition cond = al);
void rsc(Register dst, Register src1, const Operand& src2,
SBit s = LeaveCC, Condition cond = al);
void tst(Register src1, const Operand& src2, Condition cond = al);
void tst(Register src1, Register src2, Condition cond = al);
void teq(Register src1, const Operand& src2, Condition cond = al);
void cmp(Register src1, const Operand& src2, Condition cond = al);
void cmp(Register src1, Register src2, Condition cond = al);
void cmp_raw_immediate(Register src1, int raw_immediate, Condition cond = al);
void cmn(Register src1, const Operand& src2, Condition cond = al);
void orr(Register dst, Register src1, const Operand& src2,
SBit s = LeaveCC, Condition cond = al);
void orr(Register dst, Register src1, Register src2,
SBit s = LeaveCC, Condition cond = al);
void mov(Register dst, const Operand& src,
SBit s = LeaveCC, Condition cond = al);
void mov(Register dst, Register src, SBit s = LeaveCC, Condition cond = al);
// Load the position of the label relative to the generated code object
// pointer in a register.
void mov_label_offset(Register dst, Label* label);
// ARMv7 instructions for loading a 32 bit immediate in two instructions.
// The constant for movw and movt should be in the range 0-0xffff.
void movw(Register reg, uint32_t immediate, Condition cond = al);
void movt(Register reg, uint32_t immediate, Condition cond = al);
void bic(Register dst, Register src1, const Operand& src2,
SBit s = LeaveCC, Condition cond = al);
void mvn(Register dst, const Operand& src,
SBit s = LeaveCC, Condition cond = al);
// Shift instructions
void asr(Register dst, Register src1, const Operand& src2, SBit s = LeaveCC,
Condition cond = al);
void lsl(Register dst, Register src1, const Operand& src2, SBit s = LeaveCC,
Condition cond = al);
void lsr(Register dst, Register src1, const Operand& src2, SBit s = LeaveCC,
Condition cond = al);
// Multiply instructions
void mla(Register dst, Register src1, Register src2, Register srcA,
SBit s = LeaveCC, Condition cond = al);
void mls(Register dst, Register src1, Register src2, Register srcA,
Condition cond = al);
void sdiv(Register dst, Register src1, Register src2,
Condition cond = al);
void udiv(Register dst, Register src1, Register src2, Condition cond = al);
void mul(Register dst, Register src1, Register src2,
SBit s = LeaveCC, Condition cond = al);
void smmla(Register dst, Register src1, Register src2, Register srcA,
Condition cond = al);
void smmul(Register dst, Register src1, Register src2, Condition cond = al);
void smlal(Register dstL, Register dstH, Register src1, Register src2,
SBit s = LeaveCC, Condition cond = al);
void smull(Register dstL, Register dstH, Register src1, Register src2,
SBit s = LeaveCC, Condition cond = al);
void umlal(Register dstL, Register dstH, Register src1, Register src2,
SBit s = LeaveCC, Condition cond = al);
void umull(Register dstL, Register dstH, Register src1, Register src2,
SBit s = LeaveCC, Condition cond = al);
// Miscellaneous arithmetic instructions
void clz(Register dst, Register src, Condition cond = al); // v5 and above
// Saturating instructions. v6 and above.
// Unsigned saturate.
//
// Saturate an optionally shifted signed value to an unsigned range.
//
// usat dst, #satpos, src
// usat dst, #satpos, src, lsl #sh
// usat dst, #satpos, src, asr #sh
//
// Register dst will contain:
//
// 0, if s < 0
// (1 << satpos) - 1, if s > ((1 << satpos) - 1)
// s, otherwise
//
// where s is the contents of src after shifting (if used.)
void usat(Register dst, int satpos, const Operand& src, Condition cond = al);
// Bitfield manipulation instructions. v7 and above.
void ubfx(Register dst, Register src, int lsb, int width,
Condition cond = al);
void sbfx(Register dst, Register src, int lsb, int width,
Condition cond = al);
void bfc(Register dst, int lsb, int width, Condition cond = al);
void bfi(Register dst, Register src, int lsb, int width,
Condition cond = al);
void pkhbt(Register dst, Register src1, const Operand& src2,
Condition cond = al);
void pkhtb(Register dst, Register src1, const Operand& src2,
Condition cond = al);
void sxtb(Register dst, Register src, int rotate = 0, Condition cond = al);
void sxtab(Register dst, Register src1, Register src2, int rotate = 0,
Condition cond = al);
void sxth(Register dst, Register src, int rotate = 0, Condition cond = al);
void sxtah(Register dst, Register src1, Register src2, int rotate = 0,
Condition cond = al);
void uxtb(Register dst, Register src, int rotate = 0, Condition cond = al);
void uxtab(Register dst, Register src1, Register src2, int rotate = 0,
Condition cond = al);
void uxtb16(Register dst, Register src, int rotate = 0, Condition cond = al);
void uxth(Register dst, Register src, int rotate = 0, Condition cond = al);
void uxtah(Register dst, Register src1, Register src2, int rotate = 0,
Condition cond = al);
// Reverse the bits in a register.
void rbit(Register dst, Register src, Condition cond = al);
void rev(Register dst, Register src, Condition cond = al);
// Status register access instructions
void mrs(Register dst, SRegister s, Condition cond = al);
void msr(SRegisterFieldMask fields, const Operand& src, Condition cond = al);
// Load/Store instructions
void ldr(Register dst, const MemOperand& src, Condition cond = al);
void str(Register src, const MemOperand& dst, Condition cond = al);
void ldrb(Register dst, const MemOperand& src, Condition cond = al);
void strb(Register src, const MemOperand& dst, Condition cond = al);
void ldrh(Register dst, const MemOperand& src, Condition cond = al);
void strh(Register src, const MemOperand& dst, Condition cond = al);
void ldrsb(Register dst, const MemOperand& src, Condition cond = al);
void ldrsh(Register dst, const MemOperand& src, Condition cond = al);
void ldrd(Register dst1,
Register dst2,
const MemOperand& src, Condition cond = al);
void strd(Register src1,
Register src2,
const MemOperand& dst, Condition cond = al);
// Load literal from a pc relative address.
void ldr_pcrel(Register dst, int imm12, Condition cond = al);
// Load/Store exclusive instructions
void ldrex(Register dst, Register src, Condition cond = al);
void strex(Register src1, Register src2, Register dst, Condition cond = al);
void ldrexb(Register dst, Register src, Condition cond = al);
void strexb(Register src1, Register src2, Register dst, Condition cond = al);
void ldrexh(Register dst, Register src, Condition cond = al);
void strexh(Register src1, Register src2, Register dst, Condition cond = al);
void ldrexd(Register dst1, Register dst2, Register src, Condition cond = al);
void strexd(Register res, Register src1, Register src2, Register dst,
Condition cond = al);
// Preload instructions
void pld(const MemOperand& address);
// Load/Store multiple instructions
void ldm(BlockAddrMode am, Register base, RegList dst, Condition cond = al);
void stm(BlockAddrMode am, Register base, RegList src, Condition cond = al);
// Exception-generating instructions and debugging support
void stop(const char* msg,
Condition cond = al,
int32_t code = kDefaultStopCode);
void bkpt(uint32_t imm16); // v5 and above
void svc(uint32_t imm24, Condition cond = al);
// Synchronization instructions.
// On ARMv6, an equivalent CP15 operation will be used.
void dmb(BarrierOption option);
void dsb(BarrierOption option);
void isb(BarrierOption option);
// Conditional speculation barrier.
void csdb();
// Coprocessor instructions
void cdp(Coprocessor coproc, int opcode_1,
CRegister crd, CRegister crn, CRegister crm,
int opcode_2, Condition cond = al);
void cdp2(Coprocessor coproc, int opcode_1,
CRegister crd, CRegister crn, CRegister crm,
int opcode_2); // v5 and above
void mcr(Coprocessor coproc, int opcode_1,
Register rd, CRegister crn, CRegister crm,
int opcode_2 = 0, Condition cond = al);
void mcr2(Coprocessor coproc, int opcode_1,
Register rd, CRegister crn, CRegister crm,
int opcode_2 = 0); // v5 and above
void mrc(Coprocessor coproc, int opcode_1,
Register rd, CRegister crn, CRegister crm,
int opcode_2 = 0, Condition cond = al);
void mrc2(Coprocessor coproc, int opcode_1,
Register rd, CRegister crn, CRegister crm,
int opcode_2 = 0); // v5 and above
void ldc(Coprocessor coproc, CRegister crd, const MemOperand& src,
LFlag l = Short, Condition cond = al);
void ldc(Coprocessor coproc, CRegister crd, Register base, int option,
LFlag l = Short, Condition cond = al);
void ldc2(Coprocessor coproc, CRegister crd, const MemOperand& src,
LFlag l = Short); // v5 and above
void ldc2(Coprocessor coproc, CRegister crd, Register base, int option,
LFlag l = Short); // v5 and above
// Support for VFP.
// All these APIs support S0 to S31 and D0 to D31.
void vldr(const DwVfpRegister dst,
const Register base,
int offset,
const Condition cond = al);
void vldr(const DwVfpRegister dst,
const MemOperand& src,
const Condition cond = al);
void vldr(const SwVfpRegister dst,
const Register base,
int offset,
const Condition cond = al);
void vldr(const SwVfpRegister dst,
const MemOperand& src,
const Condition cond = al);
void vstr(const DwVfpRegister src,
const Register base,
int offset,
const Condition cond = al);
void vstr(const DwVfpRegister src,
const MemOperand& dst,
const Condition cond = al);
void vstr(const SwVfpRegister src,
const Register base,
int offset,
const Condition cond = al);
void vstr(const SwVfpRegister src,
const MemOperand& dst,
const Condition cond = al);
void vldm(BlockAddrMode am,
Register base,
DwVfpRegister first,
DwVfpRegister last,
Condition cond = al);
void vstm(BlockAddrMode am,
Register base,
DwVfpRegister first,
DwVfpRegister last,
Condition cond = al);
void vldm(BlockAddrMode am,
Register base,
SwVfpRegister first,
SwVfpRegister last,
Condition cond = al);
void vstm(BlockAddrMode am,
Register base,
SwVfpRegister first,
SwVfpRegister last,
Condition cond = al);
void vmov(const SwVfpRegister dst, Float32 imm);
void vmov(const DwVfpRegister dst,
Double imm,
const Register extra_scratch = no_reg);
void vmov(const SwVfpRegister dst,
const SwVfpRegister src,
const Condition cond = al);
void vmov(const DwVfpRegister dst,
const DwVfpRegister src,
const Condition cond = al);
void vmov(const DwVfpRegister dst,
const Register src1,
const Register src2,
const Condition cond = al);
void vmov(const Register dst1,
const Register dst2,
const DwVfpRegister src,
const Condition cond = al);
void vmov(const SwVfpRegister dst,
const Register src,
const Condition cond = al);
void vmov(const Register dst,
const SwVfpRegister src,
const Condition cond = al);
void vcvt_f64_s32(const DwVfpRegister dst,
const SwVfpRegister src,
VFPConversionMode mode = kDefaultRoundToZero,
const Condition cond = al);
void vcvt_f32_s32(const SwVfpRegister dst,
const SwVfpRegister src,
VFPConversionMode mode = kDefaultRoundToZero,
const Condition cond = al);
void vcvt_f64_u32(const DwVfpRegister dst,
const SwVfpRegister src,
VFPConversionMode mode = kDefaultRoundToZero,
const Condition cond = al);
void vcvt_f32_u32(const SwVfpRegister dst,
const SwVfpRegister src,
VFPConversionMode mode = kDefaultRoundToZero,
const Condition cond = al);
void vcvt_s32_f32(const SwVfpRegister dst,
const SwVfpRegister src,
VFPConversionMode mode = kDefaultRoundToZero,
const Condition cond = al);
void vcvt_u32_f32(const SwVfpRegister dst,
const SwVfpRegister src,
VFPConversionMode mode = kDefaultRoundToZero,
const Condition cond = al);
void vcvt_s32_f64(const SwVfpRegister dst,
const DwVfpRegister src,
VFPConversionMode mode = kDefaultRoundToZero,
const Condition cond = al);
void vcvt_u32_f64(const SwVfpRegister dst,
const DwVfpRegister src,
VFPConversionMode mode = kDefaultRoundToZero,
const Condition cond = al);
void vcvt_f64_f32(const DwVfpRegister dst,
const SwVfpRegister src,
VFPConversionMode mode = kDefaultRoundToZero,
const Condition cond = al);
void vcvt_f32_f64(const SwVfpRegister dst,
const DwVfpRegister src,
VFPConversionMode mode = kDefaultRoundToZero,
const Condition cond = al);
void vcvt_f64_s32(const DwVfpRegister dst,
int fraction_bits,
const Condition cond = al);
void vmrs(const Register dst, const Condition cond = al);
void vmsr(const Register dst, const Condition cond = al);
void vneg(const DwVfpRegister dst,
const DwVfpRegister src,
const Condition cond = al);
void vneg(const SwVfpRegister dst, const SwVfpRegister src,
const Condition cond = al);
void vabs(const DwVfpRegister dst,
const DwVfpRegister src,
const Condition cond = al);
void vabs(const SwVfpRegister dst, const SwVfpRegister src,
const Condition cond = al);
void vadd(const DwVfpRegister dst,
const DwVfpRegister src1,
const DwVfpRegister src2,
const Condition cond = al);
void vadd(const SwVfpRegister dst, const SwVfpRegister src1,
const SwVfpRegister src2, const Condition cond = al);
void vsub(const DwVfpRegister dst,
const DwVfpRegister src1,
const DwVfpRegister src2,
const Condition cond = al);
void vsub(const SwVfpRegister dst, const SwVfpRegister src1,
const SwVfpRegister src2, const Condition cond = al);
void vmul(const DwVfpRegister dst,
const DwVfpRegister src1,
const DwVfpRegister src2,
const Condition cond = al);
void vmul(const SwVfpRegister dst, const SwVfpRegister src1,
const SwVfpRegister src2, const Condition cond = al);
void vmla(const DwVfpRegister dst,
const DwVfpRegister src1,
const DwVfpRegister src2,
const Condition cond = al);
void vmla(const SwVfpRegister dst, const SwVfpRegister src1,
const SwVfpRegister src2, const Condition cond = al);
void vmls(const DwVfpRegister dst,
const DwVfpRegister src1,
const DwVfpRegister src2,
const Condition cond = al);
void vmls(const SwVfpRegister dst, const SwVfpRegister src1,
const SwVfpRegister src2, const Condition cond = al);
void vdiv(const DwVfpRegister dst,
const DwVfpRegister src1,
const DwVfpRegister src2,
const Condition cond = al);
void vdiv(const SwVfpRegister dst, const SwVfpRegister src1,
const SwVfpRegister src2, const Condition cond = al);
void vcmp(const DwVfpRegister src1,
const DwVfpRegister src2,
const Condition cond = al);
void vcmp(const SwVfpRegister src1, const SwVfpRegister src2,
const Condition cond = al);
void vcmp(const DwVfpRegister src1,
const double src2,
const Condition cond = al);
void vcmp(const SwVfpRegister src1, const float src2,
const Condition cond = al);
void vmaxnm(const DwVfpRegister dst,
const DwVfpRegister src1,
const DwVfpRegister src2);
void vmaxnm(const SwVfpRegister dst,
const SwVfpRegister src1,
const SwVfpRegister src2);
void vminnm(const DwVfpRegister dst,
const DwVfpRegister src1,
const DwVfpRegister src2);
void vminnm(const SwVfpRegister dst,
const SwVfpRegister src1,
const SwVfpRegister src2);
// VSEL supports cond in {eq, ne, ge, lt, gt, le, vs, vc}.
void vsel(const Condition cond,
const DwVfpRegister dst,
const DwVfpRegister src1,
const DwVfpRegister src2);
void vsel(const Condition cond,
const SwVfpRegister dst,
const SwVfpRegister src1,
const SwVfpRegister src2);
void vsqrt(const DwVfpRegister dst,
const DwVfpRegister src,
const Condition cond = al);
void vsqrt(const SwVfpRegister dst, const SwVfpRegister src,
const Condition cond = al);
// ARMv8 rounding instructions.
void vrinta(const SwVfpRegister dst, const SwVfpRegister src);
void vrinta(const DwVfpRegister dst, const DwVfpRegister src);
void vrintn(const SwVfpRegister dst, const SwVfpRegister src);
void vrintn(const DwVfpRegister dst, const DwVfpRegister src);
void vrintm(const SwVfpRegister dst, const SwVfpRegister src);
void vrintm(const DwVfpRegister dst, const DwVfpRegister src);
void vrintp(const SwVfpRegister dst, const SwVfpRegister src);
void vrintp(const DwVfpRegister dst, const DwVfpRegister src);
void vrintz(const SwVfpRegister dst, const SwVfpRegister src,
const Condition cond = al);
void vrintz(const DwVfpRegister dst, const DwVfpRegister src,
const Condition cond = al);
// Support for NEON.
// All these APIs support D0 to D31 and Q0 to Q15.
void vld1(NeonSize size,
const NeonListOperand& dst,
const NeonMemOperand& src);
void vst1(NeonSize size,
const NeonListOperand& src,
const NeonMemOperand& dst);
// dt represents the narrower type
void vmovl(NeonDataType dt, QwNeonRegister dst, DwVfpRegister src);
// dt represents the narrower type.
void vqmovn(NeonDataType dt, DwVfpRegister dst, QwNeonRegister src);
// Only unconditional core <-> scalar moves are currently supported.
void vmov(NeonDataType dt, DwVfpRegister dst, int index, Register src);
void vmov(NeonDataType dt, Register dst, DwVfpRegister src, int index);
void vmov(QwNeonRegister dst, QwNeonRegister src);
void vdup(NeonSize size, QwNeonRegister dst, Register src);
void vdup(NeonSize size, QwNeonRegister dst, DwVfpRegister src, int index);
void vdup(NeonSize size, DwVfpRegister dst, DwVfpRegister src, int index);
void vcvt_f32_s32(QwNeonRegister dst, QwNeonRegister src);
void vcvt_f32_u32(QwNeonRegister dst, QwNeonRegister src);
void vcvt_s32_f32(QwNeonRegister dst, QwNeonRegister src);
void vcvt_u32_f32(QwNeonRegister dst, QwNeonRegister src);
void vmvn(QwNeonRegister dst, QwNeonRegister src);
void vswp(DwVfpRegister dst, DwVfpRegister src);
void vswp(QwNeonRegister dst, QwNeonRegister src);
void vabs(QwNeonRegister dst, QwNeonRegister src);
void vabs(NeonSize size, QwNeonRegister dst, QwNeonRegister src);
void vneg(QwNeonRegister dst, QwNeonRegister src);
void vneg(NeonSize size, QwNeonRegister dst, QwNeonRegister src);
void vand(QwNeonRegister dst, QwNeonRegister src1, QwNeonRegister src2);
void veor(DwVfpRegister dst, DwVfpRegister src1, DwVfpRegister src2);
void veor(QwNeonRegister dst, QwNeonRegister src1, QwNeonRegister src2);
void vbsl(QwNeonRegister dst, QwNeonRegister src1, QwNeonRegister src2);
void vorr(QwNeonRegister dst, QwNeonRegister src1, QwNeonRegister src2);
void vadd(QwNeonRegister dst, QwNeonRegister src1, QwNeonRegister src2);
void vadd(NeonSize size, QwNeonRegister dst, QwNeonRegister src1,
QwNeonRegister src2);
void vqadd(NeonDataType dt, QwNeonRegister dst, QwNeonRegister src1,
QwNeonRegister src2);
void vsub(QwNeonRegister dst, QwNeonRegister src1, QwNeonRegister src2);
void vsub(NeonSize size, QwNeonRegister dst, QwNeonRegister src1,
QwNeonRegister src2);
void vqsub(NeonDataType dt, QwNeonRegister dst, QwNeonRegister src1,
QwNeonRegister src2);
void vmul(QwNeonRegister dst, QwNeonRegister src1,
QwNeonRegister src2);
void vmul(NeonSize size, QwNeonRegister dst, QwNeonRegister src1,
QwNeonRegister src2);
void vmin(QwNeonRegister dst, QwNeonRegister src1, QwNeonRegister src2);
void vmin(NeonDataType dt, QwNeonRegister dst,
QwNeonRegister src1, QwNeonRegister src2);
void vmax(QwNeonRegister dst, QwNeonRegister src1, QwNeonRegister src2);
void vmax(NeonDataType dt, QwNeonRegister dst,
QwNeonRegister src1, QwNeonRegister src2);
void vpadd(DwVfpRegister dst, DwVfpRegister src1, DwVfpRegister src2);
void vpadd(NeonSize size, DwVfpRegister dst, DwVfpRegister src1,
DwVfpRegister src2);
void vpmin(NeonDataType dt, DwVfpRegister dst, DwVfpRegister src1,
DwVfpRegister src2);
void vpmax(NeonDataType dt, DwVfpRegister dst, DwVfpRegister src1,
DwVfpRegister src2);
void vshl(NeonDataType dt, QwNeonRegister dst, QwNeonRegister src, int shift);
void vshr(NeonDataType dt, QwNeonRegister dst, QwNeonRegister src, int shift);
void vsli(NeonSize size, DwVfpRegister dst, DwVfpRegister src, int shift);
void vsri(NeonSize size, DwVfpRegister dst, DwVfpRegister src, int shift);
// vrecpe and vrsqrte only support floating point lanes.
void vrecpe(QwNeonRegister dst, QwNeonRegister src);
void vrsqrte(QwNeonRegister dst, QwNeonRegister src);
void vrecps(QwNeonRegister dst, QwNeonRegister src1, QwNeonRegister src2);
void vrsqrts(QwNeonRegister dst, QwNeonRegister src1, QwNeonRegister src2);
void vtst(NeonSize size, QwNeonRegister dst, QwNeonRegister src1,
QwNeonRegister src2);
void vceq(QwNeonRegister dst, QwNeonRegister src1, QwNeonRegister src2);
void vceq(NeonSize size, QwNeonRegister dst, QwNeonRegister src1,
QwNeonRegister src2);
void vcge(QwNeonRegister dst, QwNeonRegister src1, QwNeonRegister src2);
void vcge(NeonDataType dt, QwNeonRegister dst, QwNeonRegister src1,
QwNeonRegister src2);
void vcgt(QwNeonRegister dst, QwNeonRegister src1, QwNeonRegister src2);
void vcgt(NeonDataType dt, QwNeonRegister dst, QwNeonRegister src1,
QwNeonRegister src2);
void vext(QwNeonRegister dst, QwNeonRegister src1, QwNeonRegister src2,
int bytes);
void vzip(NeonSize size, DwVfpRegister src1, DwVfpRegister src2);
void vzip(NeonSize size, QwNeonRegister src1, QwNeonRegister src2);
void vuzp(NeonSize size, DwVfpRegister src1, DwVfpRegister src2);
void vuzp(NeonSize size, QwNeonRegister src1, QwNeonRegister src2);
void vrev16(NeonSize size, QwNeonRegister dst, QwNeonRegister src);
void vrev32(NeonSize size, QwNeonRegister dst, QwNeonRegister src);
void vrev64(NeonSize size, QwNeonRegister dst, QwNeonRegister src);
void vtrn(NeonSize size, DwVfpRegister src1, DwVfpRegister src2);
void vtrn(NeonSize size, QwNeonRegister src1, QwNeonRegister src2);
void vtbl(DwVfpRegister dst, const NeonListOperand& list,
DwVfpRegister index);
void vtbx(DwVfpRegister dst, const NeonListOperand& list,
DwVfpRegister index);
// Pseudo instructions
// Different nop operations are used by the code generator to detect certain
// states of the generated code.
enum NopMarkerTypes {
NON_MARKING_NOP = 0,
DEBUG_BREAK_NOP,
// IC markers.
PROPERTY_ACCESS_INLINED,
PROPERTY_ACCESS_INLINED_CONTEXT,
PROPERTY_ACCESS_INLINED_CONTEXT_DONT_DELETE,
// Helper values.
LAST_CODE_MARKER,
FIRST_IC_MARKER = PROPERTY_ACCESS_INLINED
};
void nop(int type = 0); // 0 is the default non-marking type.
void push(Register src, Condition cond = al) {
str(src, MemOperand(sp, 4, NegPreIndex), cond);
}
void pop(Register dst, Condition cond = al) {
ldr(dst, MemOperand(sp, 4, PostIndex), cond);
}
void pop();
void vpush(QwNeonRegister src, Condition cond = al) {
vstm(db_w, sp, src.low(), src.high(), cond);
}
void vpush(DwVfpRegister src, Condition cond = al) {
vstm(db_w, sp, src, src, cond);
}
void vpush(SwVfpRegister src, Condition cond = al) {
vstm(db_w, sp, src, src, cond);
}
void vpop(DwVfpRegister dst, Condition cond = al) {
vldm(ia_w, sp, dst, dst, cond);
}
// Jump unconditionally to given label.
void jmp(Label* L) { b(L, al); }
// Check the code size generated from label to here.
int SizeOfCodeGeneratedSince(Label* label) {
return pc_offset() - label->pos();
}
// Check the number of instructions generated from label to here.
int InstructionsGeneratedSince(Label* label) {
return SizeOfCodeGeneratedSince(label) / kInstrSize;
}
// Check whether an immediate fits an addressing mode 1 instruction.
static bool ImmediateFitsAddrMode1Instruction(int32_t imm32);
// Check whether an immediate fits an addressing mode 2 instruction.
bool ImmediateFitsAddrMode2Instruction(int32_t imm32);
// Class for scoping postponing the constant pool generation.
class BlockConstPoolScope {
public:
explicit BlockConstPoolScope(Assembler* assem) : assem_(assem) {
assem_->StartBlockConstPool();
}
~BlockConstPoolScope() {
assem_->EndBlockConstPool();
}
private:
Assembler* assem_;
DISALLOW_IMPLICIT_CONSTRUCTORS(BlockConstPoolScope);
};
// Unused on this architecture.
void MaybeEmitOutOfLineConstantPool() {}
// Record a deoptimization reason that can be used by a log or cpu profiler.
// Use --trace-deopt to enable.
void RecordDeoptReason(DeoptimizeReason reason, SourcePosition position,
int id);
// Record the emission of a constant pool.
//
// The emission of constant pool depends on the size of the code generated and
// the number of RelocInfo recorded.
// The Debug mechanism needs to map code offsets between two versions of a
// function, compiled with and without debugger support (see for example
// Debug::PrepareForBreakPoints()).
// Compiling functions with debugger support generates additional code
// (DebugCodegen::GenerateSlot()). This may affect the emission of the
// constant pools and cause the version of the code with debugger support to
// have constant pools generated in different places.
// Recording the position and size of emitted constant pools allows to
// correctly compute the offset mappings between the different versions of a
// function in all situations.
//
// The parameter indicates the size of the constant pool (in bytes), including
// the marker and branch over the data.
void RecordConstPool(int size);
// Writes a single byte or word of data in the code stream. Used
// for inline tables, e.g., jump-tables. CheckConstantPool() should be
// called before any use of db/dd/dq/dp to ensure that constant pools
// are not emitted as part of the tables generated.
void db(uint8_t data);
void dd(uint32_t data);
void dq(uint64_t data);
void dp(uintptr_t data) { dd(data); }
// Read/patch instructions
Instr instr_at(int pos) {
return *reinterpret_cast<Instr*>(buffer_start_ + pos);
}
void instr_at_put(int pos, Instr instr) {
*reinterpret_cast<Instr*>(buffer_start_ + pos) = instr;
}
static Instr instr_at(Address pc) { return *reinterpret_cast<Instr*>(pc); }
static void instr_at_put(Address pc, Instr instr) {
*reinterpret_cast<Instr*>(pc) = instr;
}
static Condition GetCondition(Instr instr);
static bool IsLdrRegisterImmediate(Instr instr);
static bool IsVldrDRegisterImmediate(Instr instr);
static int GetLdrRegisterImmediateOffset(Instr instr);
static int GetVldrDRegisterImmediateOffset(Instr instr);
static Instr SetLdrRegisterImmediateOffset(Instr instr, int offset);
static Instr SetVldrDRegisterImmediateOffset(Instr instr, int offset);
static bool IsStrRegisterImmediate(Instr instr);
static Instr SetStrRegisterImmediateOffset(Instr instr, int offset);
static bool IsAddRegisterImmediate(Instr instr);
static Instr SetAddRegisterImmediateOffset(Instr instr, int offset);
static Register GetRd(Instr instr);
static Register GetRn(Instr instr);
static Register GetRm(Instr instr);
static bool IsPush(Instr instr);
static bool IsPop(Instr instr);
static bool IsStrRegFpOffset(Instr instr);
static bool IsLdrRegFpOffset(Instr instr);
static bool IsStrRegFpNegOffset(Instr instr);
static bool IsLdrRegFpNegOffset(Instr instr);
static bool IsLdrPcImmediateOffset(Instr instr);
static bool IsBOrBlPcImmediateOffset(Instr instr);
static bool IsVldrDPcImmediateOffset(Instr instr);
static bool IsBlxReg(Instr instr);
static bool IsBlxIp(Instr instr);
static bool IsTstImmediate(Instr instr);
static bool IsCmpRegister(Instr instr);
static bool IsCmpImmediate(Instr instr);
static Register GetCmpImmediateRegister(Instr instr);
static int GetCmpImmediateRawImmediate(Instr instr);
static bool IsNop(Instr instr, int type = NON_MARKING_NOP);
static bool IsMovImmed(Instr instr);
static bool IsOrrImmed(Instr instr);
static bool IsMovT(Instr instr);
static Instr GetMovTPattern();
static bool IsMovW(Instr instr);
static Instr GetMovWPattern();
static Instr EncodeMovwImmediate(uint32_t immediate);
static Instr PatchMovwImmediate(Instr instruction, uint32_t immediate);
static int DecodeShiftImm(Instr instr);
static Instr PatchShiftImm(Instr instr, int immed);
// Constants in pools are accessed via pc relative addressing, which can
// reach +/-4KB for integer PC-relative loads and +/-1KB for floating-point
// PC-relative loads, thereby defining a maximum distance between the
// instruction and the accessed constant.
static constexpr int kMaxDistToIntPool = 4 * KB;
// All relocations could be integer, it therefore acts as the limit.
static constexpr int kMinNumPendingConstants = 4;
static constexpr int kMaxNumPending32Constants =
kMaxDistToIntPool / kInstrSize;
// Postpone the generation of the constant pool for the specified number of
// instructions.
void BlockConstPoolFor(int instructions);
// Check if is time to emit a constant pool.
void CheckConstPool(bool force_emit, bool require_jump);
void MaybeCheckConstPool() {
if (pc_offset() >= next_buffer_check_) {
CheckConstPool(false, true);
}
}
// Move a 32-bit immediate into a register, potentially via the constant pool.
void Move32BitImmediate(Register rd, const Operand& x, Condition cond = al);
// Get the code target object for a pc-relative call or jump.
V8_INLINE Handle<Code> relative_code_target_object_handle_at(
Address pc_) const;
protected:
int buffer_space() const { return reloc_info_writer.pos() - pc_; }
// Decode branch instruction at pos and return branch target pos
int target_at(int pos);
// Patch branch instruction at pos to branch to given branch target pos
void target_at_put(int pos, int target_pos);
// Prevent contant pool emission until EndBlockConstPool is called.
// Calls to this function can be nested but must be followed by an equal
// number of call to EndBlockConstpool.
void StartBlockConstPool() {
if (const_pool_blocked_nesting_++ == 0) {
// Prevent constant pool checks happening by setting the next check to
// the biggest possible offset.
next_buffer_check_ = kMaxInt;
}
}
// Resume constant pool emission. Needs to be called as many times as
// StartBlockConstPool to have an effect.
void EndBlockConstPool() {
if (--const_pool_blocked_nesting_ == 0) {
#ifdef DEBUG
// Max pool start (if we need a jump and an alignment).
int start = pc_offset() + kInstrSize + 2 * kPointerSize;
// Check the constant pool hasn't been blocked for too long.
DCHECK(pending_32_bit_constants_.empty() ||
(start < first_const_pool_32_use_ + kMaxDistToIntPool));
#endif
// Two cases:
// * no_const_pool_before_ >= next_buffer_check_ and the emission is
// still blocked
// * no_const_pool_before_ < next_buffer_check_ and the next emit will
// trigger a check.
next_buffer_check_ = no_const_pool_before_;
}
}
bool is_const_pool_blocked() const {
return (const_pool_blocked_nesting_ > 0) ||
(pc_offset() < no_const_pool_before_);
}
bool VfpRegisterIsAvailable(DwVfpRegister reg) {
DCHECK(reg.is_valid());
return IsEnabled(VFP32DREGS) ||
(reg.code() < LowDwVfpRegister::kNumRegisters);
}
bool VfpRegisterIsAvailable(QwNeonRegister reg) {
DCHECK(reg.is_valid());
return IsEnabled(VFP32DREGS) ||
(reg.code() < LowDwVfpRegister::kNumRegisters / 2);
}
inline void emit(Instr x);
// Code generation
// The relocation writer's position is at least kGap bytes below the end of
// the generated instructions. This is so that multi-instruction sequences do
// not have to check for overflow. The same is true for writes of large
// relocation info entries.
static constexpr int kGap = 32;
// Relocation info generation
// Each relocation is encoded as a variable size value
static constexpr int kMaxRelocSize = RelocInfoWriter::kMaxSize;
RelocInfoWriter reloc_info_writer;
// ConstantPoolEntry records are used during code generation as temporary
// containers for constants and code target addresses until they are emitted
// to the constant pool. These records are temporarily stored in a separate
// buffer until a constant pool is emitted.
// If every instruction in a long sequence is accessing the pool, we need one
// pending relocation entry per instruction.
// The buffers of pending constant pool entries.
std::vector<ConstantPoolEntry> pending_32_bit_constants_;
// Scratch registers available for use by the Assembler.
RegList scratch_register_list_;
VfpRegList scratch_vfp_register_list_;
private:
// Avoid overflows for displacements etc.
static const int kMaximalBufferSize = 512 * MB;
int next_buffer_check_; // pc offset of next buffer check
// Constant pool generation
// Pools are emitted in the instruction stream, preferably after unconditional
// jumps or after returns from functions (in dead code locations).
// If a long code sequence does not contain unconditional jumps, it is
// necessary to emit the constant pool before the pool gets too far from the
// location it is accessed from. In this case, we emit a jump over the emitted
// constant pool.
// Constants in the pool may be addresses of functions that gets relocated;
// if so, a relocation info entry is associated to the constant pool entry.
// Repeated checking whether the constant pool should be emitted is rather
// expensive. By default we only check again once a number of instructions
// has been generated. That also means that the sizing of the buffers is not
// an exact science, and that we rely on some slop to not overrun buffers.
static constexpr int kCheckPoolIntervalInst = 32;
static constexpr int kCheckPoolInterval = kCheckPoolIntervalInst * kInstrSize;
// Emission of the constant pool may be blocked in some code sequences.
int const_pool_blocked_nesting_; // Block emission if this is not zero.
int no_const_pool_before_; // Block emission before this pc offset.
// Keep track of the first instruction requiring a constant pool entry
// since the previous constant pool was emitted.
int first_const_pool_32_use_;
// The bound position, before this we cannot do instruction elimination.
int last_bound_pos_;
inline void CheckBuffer();
void GrowBuffer();
// Instruction generation
void AddrMode1(Instr instr, Register rd, Register rn, const Operand& x);
// Attempt to encode operand |x| for instruction |instr| and return true on
// success. The result will be encoded in |instr| directly. This method may
// change the opcode if deemed beneficial, for instance, MOV may be turned
// into MVN, ADD into SUB, AND into BIC, ...etc. The only reason this method
// may fail is that the operand is an immediate that cannot be encoded.
bool AddrMode1TryEncodeOperand(Instr* instr, const Operand& x);
void AddrMode2(Instr instr, Register rd, const MemOperand& x);
void AddrMode3(Instr instr, Register rd, const MemOperand& x);
void AddrMode4(Instr instr, Register rn, RegList rl);
void AddrMode5(Instr instr, CRegister crd, const MemOperand& x);
// Labels
void print(const Label* L);
void bind_to(Label* L, int pos);
void next(Label* L);
// Record reloc info for current pc_
void RecordRelocInfo(RelocInfo::Mode rmode, intptr_t data = 0);
void ConstantPoolAddEntry(int position, RelocInfo::Mode rmode,
intptr_t value);
void AllocateAndInstallRequestedHeapObjects(Isolate* isolate);
int WriteCodeComments();
friend class RelocInfo;
friend class BlockConstPoolScope;
friend class EnsureSpace;
friend class UseScratchRegisterScope;
};
class EnsureSpace {
public:
V8_INLINE explicit EnsureSpace(Assembler* assembler);
};
class PatchingAssembler : public Assembler {
public:
PatchingAssembler(const AssemblerOptions& options, byte* address,
int instructions);
~PatchingAssembler();
void Emit(Address addr);
void PadWithNops();
};
// This scope utility allows scratch registers to be managed safely. The
// Assembler's GetScratchRegisterList() is used as a pool of scratch
// registers. These registers can be allocated on demand, and will be returned
// at the end of the scope.
//
// When the scope ends, the Assembler's list will be restored to its original
// state, even if the list is modified by some other means. Note that this scope
// can be nested but the destructors need to run in the opposite order as the
// constructors. We do not have assertions for this.
class V8_EXPORT_PRIVATE UseScratchRegisterScope {
public:
explicit UseScratchRegisterScope(Assembler* assembler);
~UseScratchRegisterScope();
// Take a register from the list and return it.
Register Acquire();
SwVfpRegister AcquireS() { return AcquireVfp<SwVfpRegister>(); }
LowDwVfpRegister AcquireLowD() { return AcquireVfp<LowDwVfpRegister>(); }
DwVfpRegister AcquireD() {
DwVfpRegister reg = AcquireVfp<DwVfpRegister>();
DCHECK(assembler_->VfpRegisterIsAvailable(reg));
return reg;
}
QwNeonRegister AcquireQ() {
QwNeonRegister reg = AcquireVfp<QwNeonRegister>();
DCHECK(assembler_->VfpRegisterIsAvailable(reg));
return reg;
}
// Check if we have registers available to acquire.
bool CanAcquire() const { return *assembler_->GetScratchRegisterList() != 0; }
bool CanAcquireD() const { return CanAcquireVfp<DwVfpRegister>(); }
private:
friend class Assembler;
friend class TurboAssembler;
template <typename T>
bool CanAcquireVfp() const;
template <typename T>
T AcquireVfp();
Assembler* assembler_;
// Available scratch registers at the start of this scope.
RegList old_available_;
VfpRegList old_available_vfp_;
};
} // namespace internal
} // namespace v8
#endif // V8_ARM_ASSEMBLER_ARM_H_