/*
* Copyright (C) 2009, 2010 Apple Inc. All rights reserved.
* Copyright (C) 2010 University of Szeged
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY APPLE INC. ``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 APPLE INC. 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.
*/
#ifndef ARMAssembler_h
#define ARMAssembler_h
#if ENABLE(ASSEMBLER) && CPU(ARM_THUMB2)
#include "AssemblerBuffer.h"
#include <wtf/Assertions.h>
#include <wtf/Vector.h>
#include <stdint.h>
namespace JSC {
namespace ARMRegisters {
typedef enum {
r0,
r1,
r2,
r3,
r4,
r5,
r6,
r7, wr = r7, // thumb work register
r8,
r9, sb = r9, // static base
r10, sl = r10, // stack limit
r11, fp = r11, // frame pointer
r12, ip = r12,
r13, sp = r13,
r14, lr = r14,
r15, pc = r15,
} RegisterID;
typedef enum {
s0,
s1,
s2,
s3,
s4,
s5,
s6,
s7,
s8,
s9,
s10,
s11,
s12,
s13,
s14,
s15,
s16,
s17,
s18,
s19,
s20,
s21,
s22,
s23,
s24,
s25,
s26,
s27,
s28,
s29,
s30,
s31,
} FPSingleRegisterID;
typedef enum {
d0,
d1,
d2,
d3,
d4,
d5,
d6,
d7,
d8,
d9,
d10,
d11,
d12,
d13,
d14,
d15,
d16,
d17,
d18,
d19,
d20,
d21,
d22,
d23,
d24,
d25,
d26,
d27,
d28,
d29,
d30,
d31,
} FPDoubleRegisterID;
typedef enum {
q0,
q1,
q2,
q3,
q4,
q5,
q6,
q7,
q8,
q9,
q10,
q11,
q12,
q13,
q14,
q15,
q16,
q17,
q18,
q19,
q20,
q21,
q22,
q23,
q24,
q25,
q26,
q27,
q28,
q29,
q30,
q31,
} FPQuadRegisterID;
inline FPSingleRegisterID asSingle(FPDoubleRegisterID reg)
{
ASSERT(reg < d16);
return (FPSingleRegisterID)(reg << 1);
}
inline FPDoubleRegisterID asDouble(FPSingleRegisterID reg)
{
ASSERT(!(reg & 1));
return (FPDoubleRegisterID)(reg >> 1);
}
}
class ARMv7Assembler;
class ARMThumbImmediate {
friend class ARMv7Assembler;
typedef uint8_t ThumbImmediateType;
static const ThumbImmediateType TypeInvalid = 0;
static const ThumbImmediateType TypeEncoded = 1;
static const ThumbImmediateType TypeUInt16 = 2;
typedef union {
int16_t asInt;
struct {
unsigned imm8 : 8;
unsigned imm3 : 3;
unsigned i : 1;
unsigned imm4 : 4;
};
// If this is an encoded immediate, then it may describe a shift, or a pattern.
struct {
unsigned shiftValue7 : 7;
unsigned shiftAmount : 5;
};
struct {
unsigned immediate : 8;
unsigned pattern : 4;
};
} ThumbImmediateValue;
// byte0 contains least significant bit; not using an array to make client code endian agnostic.
typedef union {
int32_t asInt;
struct {
uint8_t byte0;
uint8_t byte1;
uint8_t byte2;
uint8_t byte3;
};
} PatternBytes;
ALWAYS_INLINE static void countLeadingZerosPartial(uint32_t& value, int32_t& zeros, const int N)
{
if (value & ~((1 << N) - 1)) /* check for any of the top N bits (of 2N bits) are set */
value >>= N; /* if any were set, lose the bottom N */
else /* if none of the top N bits are set, */
zeros += N; /* then we have identified N leading zeros */
}
static int32_t countLeadingZeros(uint32_t value)
{
if (!value)
return 32;
int32_t zeros = 0;
countLeadingZerosPartial(value, zeros, 16);
countLeadingZerosPartial(value, zeros, 8);
countLeadingZerosPartial(value, zeros, 4);
countLeadingZerosPartial(value, zeros, 2);
countLeadingZerosPartial(value, zeros, 1);
return zeros;
}
ARMThumbImmediate()
: m_type(TypeInvalid)
{
m_value.asInt = 0;
}
ARMThumbImmediate(ThumbImmediateType type, ThumbImmediateValue value)
: m_type(type)
, m_value(value)
{
}
ARMThumbImmediate(ThumbImmediateType type, uint16_t value)
: m_type(TypeUInt16)
{
// Make sure this constructor is only reached with type TypeUInt16;
// this extra parameter makes the code a little clearer by making it
// explicit at call sites which type is being constructed
ASSERT_UNUSED(type, type == TypeUInt16);
m_value.asInt = value;
}
public:
static ARMThumbImmediate makeEncodedImm(uint32_t value)
{
ThumbImmediateValue encoding;
encoding.asInt = 0;
// okay, these are easy.
if (value < 256) {
encoding.immediate = value;
encoding.pattern = 0;
return ARMThumbImmediate(TypeEncoded, encoding);
}
int32_t leadingZeros = countLeadingZeros(value);
// if there were 24 or more leading zeros, then we'd have hit the (value < 256) case.
ASSERT(leadingZeros < 24);
// Given a number with bit fields Z:B:C, where count(Z)+count(B)+count(C) == 32,
// Z are the bits known zero, B is the 8-bit immediate, C are the bits to check for
// zero. count(B) == 8, so the count of bits to be checked is 24 - count(Z).
int32_t rightShiftAmount = 24 - leadingZeros;
if (value == ((value >> rightShiftAmount) << rightShiftAmount)) {
// Shift the value down to the low byte position. The assign to
// shiftValue7 drops the implicit top bit.
encoding.shiftValue7 = value >> rightShiftAmount;
// The endoded shift amount is the magnitude of a right rotate.
encoding.shiftAmount = 8 + leadingZeros;
return ARMThumbImmediate(TypeEncoded, encoding);
}
PatternBytes bytes;
bytes.asInt = value;
if ((bytes.byte0 == bytes.byte1) && (bytes.byte0 == bytes.byte2) && (bytes.byte0 == bytes.byte3)) {
encoding.immediate = bytes.byte0;
encoding.pattern = 3;
return ARMThumbImmediate(TypeEncoded, encoding);
}
if ((bytes.byte0 == bytes.byte2) && !(bytes.byte1 | bytes.byte3)) {
encoding.immediate = bytes.byte0;
encoding.pattern = 1;
return ARMThumbImmediate(TypeEncoded, encoding);
}
if ((bytes.byte1 == bytes.byte3) && !(bytes.byte0 | bytes.byte2)) {
encoding.immediate = bytes.byte1;
encoding.pattern = 2;
return ARMThumbImmediate(TypeEncoded, encoding);
}
return ARMThumbImmediate();
}
static ARMThumbImmediate makeUInt12(int32_t value)
{
return (!(value & 0xfffff000))
? ARMThumbImmediate(TypeUInt16, (uint16_t)value)
: ARMThumbImmediate();
}
static ARMThumbImmediate makeUInt12OrEncodedImm(int32_t value)
{
// If this is not a 12-bit unsigned it, try making an encoded immediate.
return (!(value & 0xfffff000))
? ARMThumbImmediate(TypeUInt16, (uint16_t)value)
: makeEncodedImm(value);
}
// The 'make' methods, above, return a !isValid() value if the argument
// cannot be represented as the requested type. This methods is called
// 'get' since the argument can always be represented.
static ARMThumbImmediate makeUInt16(uint16_t value)
{
return ARMThumbImmediate(TypeUInt16, value);
}
bool isValid()
{
return m_type != TypeInvalid;
}
// These methods rely on the format of encoded byte values.
bool isUInt3() { return !(m_value.asInt & 0xfff8); }
bool isUInt4() { return !(m_value.asInt & 0xfff0); }
bool isUInt5() { return !(m_value.asInt & 0xffe0); }
bool isUInt6() { return !(m_value.asInt & 0xffc0); }
bool isUInt7() { return !(m_value.asInt & 0xff80); }
bool isUInt8() { return !(m_value.asInt & 0xff00); }
bool isUInt9() { return (m_type == TypeUInt16) && !(m_value.asInt & 0xfe00); }
bool isUInt10() { return (m_type == TypeUInt16) && !(m_value.asInt & 0xfc00); }
bool isUInt12() { return (m_type == TypeUInt16) && !(m_value.asInt & 0xf000); }
bool isUInt16() { return m_type == TypeUInt16; }
uint8_t getUInt3() { ASSERT(isUInt3()); return m_value.asInt; }
uint8_t getUInt4() { ASSERT(isUInt4()); return m_value.asInt; }
uint8_t getUInt5() { ASSERT(isUInt5()); return m_value.asInt; }
uint8_t getUInt6() { ASSERT(isUInt6()); return m_value.asInt; }
uint8_t getUInt7() { ASSERT(isUInt7()); return m_value.asInt; }
uint8_t getUInt8() { ASSERT(isUInt8()); return m_value.asInt; }
uint8_t getUInt9() { ASSERT(isUInt9()); return m_value.asInt; }
uint8_t getUInt10() { ASSERT(isUInt10()); return m_value.asInt; }
uint16_t getUInt12() { ASSERT(isUInt12()); return m_value.asInt; }
uint16_t getUInt16() { ASSERT(isUInt16()); return m_value.asInt; }
bool isEncodedImm() { return m_type == TypeEncoded; }
private:
ThumbImmediateType m_type;
ThumbImmediateValue m_value;
};
typedef enum {
SRType_LSL,
SRType_LSR,
SRType_ASR,
SRType_ROR,
SRType_RRX = SRType_ROR
} ARMShiftType;
class ShiftTypeAndAmount {
friend class ARMv7Assembler;
public:
ShiftTypeAndAmount()
{
m_u.type = (ARMShiftType)0;
m_u.amount = 0;
}
ShiftTypeAndAmount(ARMShiftType type, unsigned amount)
{
m_u.type = type;
m_u.amount = amount & 31;
}
unsigned lo4() { return m_u.lo4; }
unsigned hi4() { return m_u.hi4; }
private:
union {
struct {
unsigned lo4 : 4;
unsigned hi4 : 4;
};
struct {
unsigned type : 2;
unsigned amount : 6;
};
} m_u;
};
class ARMv7Assembler {
public:
~ARMv7Assembler()
{
ASSERT(m_jumpsToLink.isEmpty());
}
typedef ARMRegisters::RegisterID RegisterID;
typedef ARMRegisters::FPSingleRegisterID FPSingleRegisterID;
typedef ARMRegisters::FPDoubleRegisterID FPDoubleRegisterID;
typedef ARMRegisters::FPQuadRegisterID FPQuadRegisterID;
// (HS, LO, HI, LS) -> (AE, B, A, BE)
// (VS, VC) -> (O, NO)
typedef enum {
ConditionEQ,
ConditionNE,
ConditionHS, ConditionCS = ConditionHS,
ConditionLO, ConditionCC = ConditionLO,
ConditionMI,
ConditionPL,
ConditionVS,
ConditionVC,
ConditionHI,
ConditionLS,
ConditionGE,
ConditionLT,
ConditionGT,
ConditionLE,
ConditionAL,
ConditionInvalid
} Condition;
enum JumpType { JumpFixed, JumpNoCondition, JumpCondition, JumpNoConditionFixedSize, JumpConditionFixedSize, JumpTypeCount };
enum JumpLinkType { LinkInvalid, LinkJumpT1, LinkJumpT2, LinkJumpT3,
LinkJumpT4, LinkConditionalJumpT4, LinkBX, LinkConditionalBX, JumpLinkTypeCount };
static const int JumpSizes[JumpLinkTypeCount];
static const int JumpPaddingSizes[JumpTypeCount];
class LinkRecord {
public:
LinkRecord(intptr_t from, intptr_t to, JumpType type, Condition condition)
: m_from(from)
, m_to(to)
, m_type(type)
, m_linkType(LinkInvalid)
, m_condition(condition)
{
}
intptr_t from() const { return m_from; }
void setFrom(intptr_t from) { m_from = from; }
intptr_t to() const { return m_to; }
JumpType type() const { return m_type; }
JumpLinkType linkType() const { return m_linkType; }
void setLinkType(JumpLinkType linkType) { ASSERT(m_linkType == LinkInvalid); m_linkType = linkType; }
Condition condition() const { return m_condition; }
private:
intptr_t m_from : 31;
intptr_t m_to : 31;
JumpType m_type : 3;
JumpLinkType m_linkType : 4;
Condition m_condition : 16;
};
class JmpSrc {
friend class ARMv7Assembler;
friend class ARMInstructionFormatter;
friend class LinkBuffer;
public:
JmpSrc()
: m_offset(-1)
{
}
private:
JmpSrc(int offset, JumpType type)
: m_offset(offset)
, m_condition(ConditionInvalid)
, m_type(type)
{
ASSERT(m_type == JumpFixed || m_type == JumpNoCondition || m_type == JumpNoConditionFixedSize);
}
JmpSrc(int offset, JumpType type, Condition condition)
: m_offset(offset)
, m_condition(condition)
, m_type(type)
{
ASSERT(m_type == JumpFixed || m_type == JumpCondition || m_type == JumpConditionFixedSize);
}
int m_offset;
Condition m_condition : 16;
JumpType m_type : 16;
};
class JmpDst {
friend class ARMv7Assembler;
friend class ARMInstructionFormatter;
friend class LinkBuffer;
public:
JmpDst()
: m_offset(-1)
, m_used(false)
{
}
bool isUsed() const { return m_used; }
bool isSet() const { return (m_offset != -1); }
void used() { m_used = true; }
private:
JmpDst(int offset)
: m_offset(offset)
, m_used(false)
{
ASSERT(m_offset == offset);
}
signed int m_offset : 31;
int m_used : 1;
};
private:
// ARMv7, Appx-A.6.3
bool BadReg(RegisterID reg)
{
return (reg == ARMRegisters::sp) || (reg == ARMRegisters::pc);
}
uint32_t singleRegisterMask(FPSingleRegisterID rdNum, int highBitsShift, int lowBitShift)
{
uint32_t rdMask = (rdNum >> 1) << highBitsShift;
if (rdNum & 1)
rdMask |= 1 << lowBitShift;
return rdMask;
}
uint32_t doubleRegisterMask(FPDoubleRegisterID rdNum, int highBitShift, int lowBitsShift)
{
uint32_t rdMask = (rdNum & 0xf) << lowBitsShift;
if (rdNum & 16)
rdMask |= 1 << highBitShift;
return rdMask;
}
typedef enum {
OP_ADD_reg_T1 = 0x1800,
OP_SUB_reg_T1 = 0x1A00,
OP_ADD_imm_T1 = 0x1C00,
OP_SUB_imm_T1 = 0x1E00,
OP_MOV_imm_T1 = 0x2000,
OP_CMP_imm_T1 = 0x2800,
OP_ADD_imm_T2 = 0x3000,
OP_SUB_imm_T2 = 0x3800,
OP_AND_reg_T1 = 0x4000,
OP_EOR_reg_T1 = 0x4040,
OP_TST_reg_T1 = 0x4200,
OP_RSB_imm_T1 = 0x4240,
OP_CMP_reg_T1 = 0x4280,
OP_ORR_reg_T1 = 0x4300,
OP_MVN_reg_T1 = 0x43C0,
OP_ADD_reg_T2 = 0x4400,
OP_MOV_reg_T1 = 0x4600,
OP_BLX = 0x4700,
OP_BX = 0x4700,
OP_STR_reg_T1 = 0x5000,
OP_LDR_reg_T1 = 0x5800,
OP_LDRH_reg_T1 = 0x5A00,
OP_LDRB_reg_T1 = 0x5C00,
OP_STR_imm_T1 = 0x6000,
OP_LDR_imm_T1 = 0x6800,
OP_LDRB_imm_T1 = 0x7800,
OP_LDRH_imm_T1 = 0x8800,
OP_STR_imm_T2 = 0x9000,
OP_LDR_imm_T2 = 0x9800,
OP_ADD_SP_imm_T1 = 0xA800,
OP_ADD_SP_imm_T2 = 0xB000,
OP_SUB_SP_imm_T1 = 0xB080,
OP_BKPT = 0xBE00,
OP_IT = 0xBF00,
OP_NOP_T1 = 0xBF00,
} OpcodeID;
typedef enum {
OP_B_T1 = 0xD000,
OP_B_T2 = 0xE000,
OP_AND_reg_T2 = 0xEA00,
OP_TST_reg_T2 = 0xEA10,
OP_ORR_reg_T2 = 0xEA40,
OP_ORR_S_reg_T2 = 0xEA50,
OP_ASR_imm_T1 = 0xEA4F,
OP_LSL_imm_T1 = 0xEA4F,
OP_LSR_imm_T1 = 0xEA4F,
OP_ROR_imm_T1 = 0xEA4F,
OP_MVN_reg_T2 = 0xEA6F,
OP_EOR_reg_T2 = 0xEA80,
OP_ADD_reg_T3 = 0xEB00,
OP_ADD_S_reg_T3 = 0xEB10,
OP_SUB_reg_T2 = 0xEBA0,
OP_SUB_S_reg_T2 = 0xEBB0,
OP_CMP_reg_T2 = 0xEBB0,
OP_VSTR = 0xED00,
OP_VLDR = 0xED10,
OP_VMOV_StoC = 0xEE00,
OP_VMOV_CtoS = 0xEE10,
OP_VMUL_T2 = 0xEE20,
OP_VADD_T2 = 0xEE30,
OP_VSUB_T2 = 0xEE30,
OP_VDIV = 0xEE80,
OP_VCMP = 0xEEB0,
OP_VCVT_FPIVFP = 0xEEB0,
OP_VMOV_IMM_T2 = 0xEEB0,
OP_VMRS = 0xEEB0,
OP_B_T3a = 0xF000,
OP_B_T4a = 0xF000,
OP_AND_imm_T1 = 0xF000,
OP_TST_imm = 0xF010,
OP_ORR_imm_T1 = 0xF040,
OP_MOV_imm_T2 = 0xF040,
OP_MVN_imm = 0xF060,
OP_EOR_imm_T1 = 0xF080,
OP_ADD_imm_T3 = 0xF100,
OP_ADD_S_imm_T3 = 0xF110,
OP_CMN_imm = 0xF110,
OP_SUB_imm_T3 = 0xF1A0,
OP_SUB_S_imm_T3 = 0xF1B0,
OP_CMP_imm_T2 = 0xF1B0,
OP_RSB_imm_T2 = 0xF1C0,
OP_ADD_imm_T4 = 0xF200,
OP_MOV_imm_T3 = 0xF240,
OP_SUB_imm_T4 = 0xF2A0,
OP_MOVT = 0xF2C0,
OP_NOP_T2a = 0xF3AF,
OP_LDRB_imm_T3 = 0xF810,
OP_LDRB_reg_T2 = 0xF810,
OP_LDRH_reg_T2 = 0xF830,
OP_LDRH_imm_T3 = 0xF830,
OP_STR_imm_T4 = 0xF840,
OP_STR_reg_T2 = 0xF840,
OP_LDR_imm_T4 = 0xF850,
OP_LDR_reg_T2 = 0xF850,
OP_LDRB_imm_T2 = 0xF890,
OP_LDRH_imm_T2 = 0xF8B0,
OP_STR_imm_T3 = 0xF8C0,
OP_LDR_imm_T3 = 0xF8D0,
OP_LSL_reg_T2 = 0xFA00,
OP_LSR_reg_T2 = 0xFA20,
OP_ASR_reg_T2 = 0xFA40,
OP_ROR_reg_T2 = 0xFA60,
OP_CLZ = 0xFAB0,
OP_SMULL_T1 = 0xFB80,
} OpcodeID1;
typedef enum {
OP_VADD_T2b = 0x0A00,
OP_VDIVb = 0x0A00,
OP_VLDRb = 0x0A00,
OP_VMOV_IMM_T2b = 0x0A00,
OP_VMUL_T2b = 0x0A00,
OP_VSTRb = 0x0A00,
OP_VMOV_CtoSb = 0x0A10,
OP_VMOV_StoCb = 0x0A10,
OP_VMRSb = 0x0A10,
OP_VCMPb = 0x0A40,
OP_VCVT_FPIVFPb = 0x0A40,
OP_VSUB_T2b = 0x0A40,
OP_NOP_T2b = 0x8000,
OP_B_T3b = 0x8000,
OP_B_T4b = 0x9000,
} OpcodeID2;
struct FourFours {
FourFours(unsigned f3, unsigned f2, unsigned f1, unsigned f0)
{
m_u.f0 = f0;
m_u.f1 = f1;
m_u.f2 = f2;
m_u.f3 = f3;
}
union {
unsigned value;
struct {
unsigned f0 : 4;
unsigned f1 : 4;
unsigned f2 : 4;
unsigned f3 : 4;
};
} m_u;
};
class ARMInstructionFormatter;
// false means else!
bool ifThenElseConditionBit(Condition condition, bool isIf)
{
return isIf ? (condition & 1) : !(condition & 1);
}
uint8_t ifThenElse(Condition condition, bool inst2if, bool inst3if, bool inst4if)
{
int mask = (ifThenElseConditionBit(condition, inst2if) << 3)
| (ifThenElseConditionBit(condition, inst3if) << 2)
| (ifThenElseConditionBit(condition, inst4if) << 1)
| 1;
ASSERT((condition != ConditionAL) || !(mask & (mask - 1)));
return (condition << 4) | mask;
}
uint8_t ifThenElse(Condition condition, bool inst2if, bool inst3if)
{
int mask = (ifThenElseConditionBit(condition, inst2if) << 3)
| (ifThenElseConditionBit(condition, inst3if) << 2)
| 2;
ASSERT((condition != ConditionAL) || !(mask & (mask - 1)));
return (condition << 4) | mask;
}
uint8_t ifThenElse(Condition condition, bool inst2if)
{
int mask = (ifThenElseConditionBit(condition, inst2if) << 3)
| 4;
ASSERT((condition != ConditionAL) || !(mask & (mask - 1)));
return (condition << 4) | mask;
}
uint8_t ifThenElse(Condition condition)
{
int mask = 8;
return (condition << 4) | mask;
}
public:
void add(RegisterID rd, RegisterID rn, ARMThumbImmediate imm)
{
// Rd can only be SP if Rn is also SP.
ASSERT((rd != ARMRegisters::sp) || (rn == ARMRegisters::sp));
ASSERT(rd != ARMRegisters::pc);
ASSERT(rn != ARMRegisters::pc);
ASSERT(imm.isValid());
if (rn == ARMRegisters::sp) {
if (!(rd & 8) && imm.isUInt10()) {
m_formatter.oneWordOp5Reg3Imm8(OP_ADD_SP_imm_T1, rd, imm.getUInt10() >> 2);
return;
} else if ((rd == ARMRegisters::sp) && imm.isUInt9()) {
m_formatter.oneWordOp9Imm7(OP_ADD_SP_imm_T2, imm.getUInt9() >> 2);
return;
}
} else if (!((rd | rn) & 8)) {
if (imm.isUInt3()) {
m_formatter.oneWordOp7Reg3Reg3Reg3(OP_ADD_imm_T1, (RegisterID)imm.getUInt3(), rn, rd);
return;
} else if ((rd == rn) && imm.isUInt8()) {
m_formatter.oneWordOp5Reg3Imm8(OP_ADD_imm_T2, rd, imm.getUInt8());
return;
}
}
if (imm.isEncodedImm())
m_formatter.twoWordOp5i6Imm4Reg4EncodedImm(OP_ADD_imm_T3, rn, rd, imm);
else {
ASSERT(imm.isUInt12());
m_formatter.twoWordOp5i6Imm4Reg4EncodedImm(OP_ADD_imm_T4, rn, rd, imm);
}
}
void add(RegisterID rd, RegisterID rn, RegisterID rm, ShiftTypeAndAmount shift)
{
ASSERT((rd != ARMRegisters::sp) || (rn == ARMRegisters::sp));
ASSERT(rd != ARMRegisters::pc);
ASSERT(rn != ARMRegisters::pc);
ASSERT(!BadReg(rm));
m_formatter.twoWordOp12Reg4FourFours(OP_ADD_reg_T3, rn, FourFours(shift.hi4(), rd, shift.lo4(), rm));
}
// NOTE: In an IT block, add doesn't modify the flags register.
void add(RegisterID rd, RegisterID rn, RegisterID rm)
{
if (rd == rn)
m_formatter.oneWordOp8RegReg143(OP_ADD_reg_T2, rm, rd);
else if (rd == rm)
m_formatter.oneWordOp8RegReg143(OP_ADD_reg_T2, rn, rd);
else if (!((rd | rn | rm) & 8))
m_formatter.oneWordOp7Reg3Reg3Reg3(OP_ADD_reg_T1, rm, rn, rd);
else
add(rd, rn, rm, ShiftTypeAndAmount());
}
// Not allowed in an IT (if then) block.
void add_S(RegisterID rd, RegisterID rn, ARMThumbImmediate imm)
{
// Rd can only be SP if Rn is also SP.
ASSERT((rd != ARMRegisters::sp) || (rn == ARMRegisters::sp));
ASSERT(rd != ARMRegisters::pc);
ASSERT(rn != ARMRegisters::pc);
ASSERT(imm.isEncodedImm());
if (!((rd | rn) & 8)) {
if (imm.isUInt3()) {
m_formatter.oneWordOp7Reg3Reg3Reg3(OP_ADD_imm_T1, (RegisterID)imm.getUInt3(), rn, rd);
return;
} else if ((rd == rn) && imm.isUInt8()) {
m_formatter.oneWordOp5Reg3Imm8(OP_ADD_imm_T2, rd, imm.getUInt8());
return;
}
}
m_formatter.twoWordOp5i6Imm4Reg4EncodedImm(OP_ADD_S_imm_T3, rn, rd, imm);
}
// Not allowed in an IT (if then) block?
void add_S(RegisterID rd, RegisterID rn, RegisterID rm, ShiftTypeAndAmount shift)
{
ASSERT((rd != ARMRegisters::sp) || (rn == ARMRegisters::sp));
ASSERT(rd != ARMRegisters::pc);
ASSERT(rn != ARMRegisters::pc);
ASSERT(!BadReg(rm));
m_formatter.twoWordOp12Reg4FourFours(OP_ADD_S_reg_T3, rn, FourFours(shift.hi4(), rd, shift.lo4(), rm));
}
// Not allowed in an IT (if then) block.
void add_S(RegisterID rd, RegisterID rn, RegisterID rm)
{
if (!((rd | rn | rm) & 8))
m_formatter.oneWordOp7Reg3Reg3Reg3(OP_ADD_reg_T1, rm, rn, rd);
else
add_S(rd, rn, rm, ShiftTypeAndAmount());
}
void ARM_and(RegisterID rd, RegisterID rn, ARMThumbImmediate imm)
{
ASSERT(!BadReg(rd));
ASSERT(!BadReg(rn));
ASSERT(imm.isEncodedImm());
m_formatter.twoWordOp5i6Imm4Reg4EncodedImm(OP_AND_imm_T1, rn, rd, imm);
}
void ARM_and(RegisterID rd, RegisterID rn, RegisterID rm, ShiftTypeAndAmount shift)
{
ASSERT(!BadReg(rd));
ASSERT(!BadReg(rn));
ASSERT(!BadReg(rm));
m_formatter.twoWordOp12Reg4FourFours(OP_AND_reg_T2, rn, FourFours(shift.hi4(), rd, shift.lo4(), rm));
}
void ARM_and(RegisterID rd, RegisterID rn, RegisterID rm)
{
if ((rd == rn) && !((rd | rm) & 8))
m_formatter.oneWordOp10Reg3Reg3(OP_AND_reg_T1, rm, rd);
else if ((rd == rm) && !((rd | rn) & 8))
m_formatter.oneWordOp10Reg3Reg3(OP_AND_reg_T1, rn, rd);
else
ARM_and(rd, rn, rm, ShiftTypeAndAmount());
}
void asr(RegisterID rd, RegisterID rm, int32_t shiftAmount)
{
ASSERT(!BadReg(rd));
ASSERT(!BadReg(rm));
ShiftTypeAndAmount shift(SRType_ASR, shiftAmount);
m_formatter.twoWordOp16FourFours(OP_ASR_imm_T1, FourFours(shift.hi4(), rd, shift.lo4(), rm));
}
void asr(RegisterID rd, RegisterID rn, RegisterID rm)
{
ASSERT(!BadReg(rd));
ASSERT(!BadReg(rn));
ASSERT(!BadReg(rm));
m_formatter.twoWordOp12Reg4FourFours(OP_ASR_reg_T2, rn, FourFours(0xf, rd, 0, rm));
}
// Only allowed in IT (if then) block if last instruction.
JmpSrc b(JumpType type)
{
m_formatter.twoWordOp16Op16(OP_B_T4a, OP_B_T4b);
return JmpSrc(m_formatter.size(), type);
}
// Only allowed in IT (if then) block if last instruction.
JmpSrc blx(RegisterID rm, JumpType type)
{
ASSERT(rm != ARMRegisters::pc);
m_formatter.oneWordOp8RegReg143(OP_BLX, rm, (RegisterID)8);
return JmpSrc(m_formatter.size(), type);
}
// Only allowed in IT (if then) block if last instruction.
JmpSrc bx(RegisterID rm, JumpType type, Condition condition)
{
m_formatter.oneWordOp8RegReg143(OP_BX, rm, (RegisterID)0);
return JmpSrc(m_formatter.size(), type, condition);
}
JmpSrc bx(RegisterID rm, JumpType type)
{
m_formatter.oneWordOp8RegReg143(OP_BX, rm, (RegisterID)0);
return JmpSrc(m_formatter.size(), type);
}
void bkpt(uint8_t imm=0)
{
m_formatter.oneWordOp8Imm8(OP_BKPT, imm);
}
void clz(RegisterID rd, RegisterID rm)
{
ASSERT(!BadReg(rd));
ASSERT(!BadReg(rm));
m_formatter.twoWordOp12Reg4FourFours(OP_CLZ, rm, FourFours(0xf, rd, 8, rm));
}
void cmn(RegisterID rn, ARMThumbImmediate imm)
{
ASSERT(rn != ARMRegisters::pc);
ASSERT(imm.isEncodedImm());
m_formatter.twoWordOp5i6Imm4Reg4EncodedImm(OP_CMN_imm, rn, (RegisterID)0xf, imm);
}
void cmp(RegisterID rn, ARMThumbImmediate imm)
{
ASSERT(rn != ARMRegisters::pc);
ASSERT(imm.isEncodedImm());
if (!(rn & 8) && imm.isUInt8())
m_formatter.oneWordOp5Reg3Imm8(OP_CMP_imm_T1, rn, imm.getUInt8());
else
m_formatter.twoWordOp5i6Imm4Reg4EncodedImm(OP_CMP_imm_T2, rn, (RegisterID)0xf, imm);
}
void cmp(RegisterID rn, RegisterID rm, ShiftTypeAndAmount shift)
{
ASSERT(rn != ARMRegisters::pc);
ASSERT(!BadReg(rm));
m_formatter.twoWordOp12Reg4FourFours(OP_CMP_reg_T2, rn, FourFours(shift.hi4(), 0xf, shift.lo4(), rm));
}
void cmp(RegisterID rn, RegisterID rm)
{
if ((rn | rm) & 8)
cmp(rn, rm, ShiftTypeAndAmount());
else
m_formatter.oneWordOp10Reg3Reg3(OP_CMP_reg_T1, rm, rn);
}
// xor is not spelled with an 'e'. :-(
void eor(RegisterID rd, RegisterID rn, ARMThumbImmediate imm)
{
ASSERT(!BadReg(rd));
ASSERT(!BadReg(rn));
ASSERT(imm.isEncodedImm());
m_formatter.twoWordOp5i6Imm4Reg4EncodedImm(OP_EOR_imm_T1, rn, rd, imm);
}
// xor is not spelled with an 'e'. :-(
void eor(RegisterID rd, RegisterID rn, RegisterID rm, ShiftTypeAndAmount shift)
{
ASSERT(!BadReg(rd));
ASSERT(!BadReg(rn));
ASSERT(!BadReg(rm));
m_formatter.twoWordOp12Reg4FourFours(OP_EOR_reg_T2, rn, FourFours(shift.hi4(), rd, shift.lo4(), rm));
}
// xor is not spelled with an 'e'. :-(
void eor(RegisterID rd, RegisterID rn, RegisterID rm)
{
if ((rd == rn) && !((rd | rm) & 8))
m_formatter.oneWordOp10Reg3Reg3(OP_EOR_reg_T1, rm, rd);
else if ((rd == rm) && !((rd | rn) & 8))
m_formatter.oneWordOp10Reg3Reg3(OP_EOR_reg_T1, rn, rd);
else
eor(rd, rn, rm, ShiftTypeAndAmount());
}
void it(Condition cond)
{
m_formatter.oneWordOp8Imm8(OP_IT, ifThenElse(cond));
}
void it(Condition cond, bool inst2if)
{
m_formatter.oneWordOp8Imm8(OP_IT, ifThenElse(cond, inst2if));
}
void it(Condition cond, bool inst2if, bool inst3if)
{
m_formatter.oneWordOp8Imm8(OP_IT, ifThenElse(cond, inst2if, inst3if));
}
void it(Condition cond, bool inst2if, bool inst3if, bool inst4if)
{
m_formatter.oneWordOp8Imm8(OP_IT, ifThenElse(cond, inst2if, inst3if, inst4if));
}
// rt == ARMRegisters::pc only allowed if last instruction in IT (if then) block.
void ldr(RegisterID rt, RegisterID rn, ARMThumbImmediate imm)
{
ASSERT(rn != ARMRegisters::pc); // LDR (literal)
ASSERT(imm.isUInt12());
if (!((rt | rn) & 8) && imm.isUInt7())
m_formatter.oneWordOp5Imm5Reg3Reg3(OP_LDR_imm_T1, imm.getUInt7() >> 2, rn, rt);
else if ((rn == ARMRegisters::sp) && !(rt & 8) && imm.isUInt10())
m_formatter.oneWordOp5Reg3Imm8(OP_LDR_imm_T2, rt, imm.getUInt10() >> 2);
else
m_formatter.twoWordOp12Reg4Reg4Imm12(OP_LDR_imm_T3, rn, rt, imm.getUInt12());
}
// If index is set, this is a regular offset or a pre-indexed load;
// if index is not set then is is a post-index load.
//
// If wback is set rn is updated - this is a pre or post index load,
// if wback is not set this is a regular offset memory access.
//
// (-255 <= offset <= 255)
// _reg = REG[rn]
// _tmp = _reg + offset
// MEM[index ? _tmp : _reg] = REG[rt]
// if (wback) REG[rn] = _tmp
void ldr(RegisterID rt, RegisterID rn, int offset, bool index, bool wback)
{
ASSERT(rt != ARMRegisters::pc);
ASSERT(rn != ARMRegisters::pc);
ASSERT(index || wback);
ASSERT(!wback | (rt != rn));
bool add = true;
if (offset < 0) {
add = false;
offset = -offset;
}
ASSERT((offset & ~0xff) == 0);
offset |= (wback << 8);
offset |= (add << 9);
offset |= (index << 10);
offset |= (1 << 11);
m_formatter.twoWordOp12Reg4Reg4Imm12(OP_LDR_imm_T4, rn, rt, offset);
}
// rt == ARMRegisters::pc only allowed if last instruction in IT (if then) block.
void ldr(RegisterID rt, RegisterID rn, RegisterID rm, unsigned shift=0)
{
ASSERT(rn != ARMRegisters::pc); // LDR (literal)
ASSERT(!BadReg(rm));
ASSERT(shift <= 3);
if (!shift && !((rt | rn | rm) & 8))
m_formatter.oneWordOp7Reg3Reg3Reg3(OP_LDR_reg_T1, rm, rn, rt);
else
m_formatter.twoWordOp12Reg4FourFours(OP_LDR_reg_T2, rn, FourFours(rt, 0, shift, rm));
}
// rt == ARMRegisters::pc only allowed if last instruction in IT (if then) block.
void ldrh(RegisterID rt, RegisterID rn, ARMThumbImmediate imm)
{
ASSERT(rn != ARMRegisters::pc); // LDR (literal)
ASSERT(imm.isUInt12());
if (!((rt | rn) & 8) && imm.isUInt6())
m_formatter.oneWordOp5Imm5Reg3Reg3(OP_LDRH_imm_T1, imm.getUInt6() >> 2, rn, rt);
else
m_formatter.twoWordOp12Reg4Reg4Imm12(OP_LDRH_imm_T2, rn, rt, imm.getUInt12());
}
// If index is set, this is a regular offset or a pre-indexed load;
// if index is not set then is is a post-index load.
//
// If wback is set rn is updated - this is a pre or post index load,
// if wback is not set this is a regular offset memory access.
//
// (-255 <= offset <= 255)
// _reg = REG[rn]
// _tmp = _reg + offset
// MEM[index ? _tmp : _reg] = REG[rt]
// if (wback) REG[rn] = _tmp
void ldrh(RegisterID rt, RegisterID rn, int offset, bool index, bool wback)
{
ASSERT(rt != ARMRegisters::pc);
ASSERT(rn != ARMRegisters::pc);
ASSERT(index || wback);
ASSERT(!wback | (rt != rn));
bool add = true;
if (offset < 0) {
add = false;
offset = -offset;
}
ASSERT((offset & ~0xff) == 0);
offset |= (wback << 8);
offset |= (add << 9);
offset |= (index << 10);
offset |= (1 << 11);
m_formatter.twoWordOp12Reg4Reg4Imm12(OP_LDRH_imm_T3, rn, rt, offset);
}
void ldrh(RegisterID rt, RegisterID rn, RegisterID rm, unsigned shift=0)
{
ASSERT(!BadReg(rt)); // Memory hint
ASSERT(rn != ARMRegisters::pc); // LDRH (literal)
ASSERT(!BadReg(rm));
ASSERT(shift <= 3);
if (!shift && !((rt | rn | rm) & 8))
m_formatter.oneWordOp7Reg3Reg3Reg3(OP_LDRH_reg_T1, rm, rn, rt);
else
m_formatter.twoWordOp12Reg4FourFours(OP_LDRH_reg_T2, rn, FourFours(rt, 0, shift, rm));
}
void ldrb(RegisterID rt, RegisterID rn, ARMThumbImmediate imm)
{
ASSERT(rn != ARMRegisters::pc); // LDR (literal)
ASSERT(imm.isUInt12());
if (!((rt | rn) & 8) && imm.isUInt5())
m_formatter.oneWordOp5Imm5Reg3Reg3(OP_LDRB_imm_T1, imm.getUInt5(), rn, rt);
else
m_formatter.twoWordOp12Reg4Reg4Imm12(OP_LDRB_imm_T2, rn, rt, imm.getUInt12());
}
void ldrb(RegisterID rt, RegisterID rn, int offset, bool index, bool wback)
{
ASSERT(rt != ARMRegisters::pc);
ASSERT(rn != ARMRegisters::pc);
ASSERT(index || wback);
ASSERT(!wback | (rt != rn));
bool add = true;
if (offset < 0) {
add = false;
offset = -offset;
}
ASSERT(!(offset & ~0xff));
offset |= (wback << 8);
offset |= (add << 9);
offset |= (index << 10);
offset |= (1 << 11);
m_formatter.twoWordOp12Reg4Reg4Imm12(OP_LDRB_imm_T3, rn, rt, offset);
}
void ldrb(RegisterID rt, RegisterID rn, RegisterID rm, unsigned shift = 0)
{
ASSERT(rn != ARMRegisters::pc); // LDR (literal)
ASSERT(!BadReg(rm));
ASSERT(shift <= 3);
if (!shift && !((rt | rn | rm) & 8))
m_formatter.oneWordOp7Reg3Reg3Reg3(OP_LDRB_reg_T1, rm, rn, rt);
else
m_formatter.twoWordOp12Reg4FourFours(OP_LDRB_reg_T2, rn, FourFours(rt, 0, shift, rm));
}
void lsl(RegisterID rd, RegisterID rm, int32_t shiftAmount)
{
ASSERT(!BadReg(rd));
ASSERT(!BadReg(rm));
ShiftTypeAndAmount shift(SRType_LSL, shiftAmount);
m_formatter.twoWordOp16FourFours(OP_LSL_imm_T1, FourFours(shift.hi4(), rd, shift.lo4(), rm));
}
void lsl(RegisterID rd, RegisterID rn, RegisterID rm)
{
ASSERT(!BadReg(rd));
ASSERT(!BadReg(rn));
ASSERT(!BadReg(rm));
m_formatter.twoWordOp12Reg4FourFours(OP_LSL_reg_T2, rn, FourFours(0xf, rd, 0, rm));
}
void lsr(RegisterID rd, RegisterID rm, int32_t shiftAmount)
{
ASSERT(!BadReg(rd));
ASSERT(!BadReg(rm));
ShiftTypeAndAmount shift(SRType_LSR, shiftAmount);
m_formatter.twoWordOp16FourFours(OP_LSR_imm_T1, FourFours(shift.hi4(), rd, shift.lo4(), rm));
}
void lsr(RegisterID rd, RegisterID rn, RegisterID rm)
{
ASSERT(!BadReg(rd));
ASSERT(!BadReg(rn));
ASSERT(!BadReg(rm));
m_formatter.twoWordOp12Reg4FourFours(OP_LSR_reg_T2, rn, FourFours(0xf, rd, 0, rm));
}
void movT3(RegisterID rd, ARMThumbImmediate imm)
{
ASSERT(imm.isValid());
ASSERT(!imm.isEncodedImm());
ASSERT(!BadReg(rd));
m_formatter.twoWordOp5i6Imm4Reg4EncodedImm(OP_MOV_imm_T3, imm.m_value.imm4, rd, imm);
}
void mov(RegisterID rd, ARMThumbImmediate imm)
{
ASSERT(imm.isValid());
ASSERT(!BadReg(rd));
if ((rd < 8) && imm.isUInt8())
m_formatter.oneWordOp5Reg3Imm8(OP_MOV_imm_T1, rd, imm.getUInt8());
else if (imm.isEncodedImm())
m_formatter.twoWordOp5i6Imm4Reg4EncodedImm(OP_MOV_imm_T2, 0xf, rd, imm);
else
movT3(rd, imm);
}
void mov(RegisterID rd, RegisterID rm)
{
m_formatter.oneWordOp8RegReg143(OP_MOV_reg_T1, rm, rd);
}
void movt(RegisterID rd, ARMThumbImmediate imm)
{
ASSERT(imm.isUInt16());
ASSERT(!BadReg(rd));
m_formatter.twoWordOp5i6Imm4Reg4EncodedImm(OP_MOVT, imm.m_value.imm4, rd, imm);
}
void mvn(RegisterID rd, ARMThumbImmediate imm)
{
ASSERT(imm.isEncodedImm());
ASSERT(!BadReg(rd));
m_formatter.twoWordOp5i6Imm4Reg4EncodedImm(OP_MVN_imm, 0xf, rd, imm);
}
void mvn(RegisterID rd, RegisterID rm, ShiftTypeAndAmount shift)
{
ASSERT(!BadReg(rd));
ASSERT(!BadReg(rm));
m_formatter.twoWordOp16FourFours(OP_MVN_reg_T2, FourFours(shift.hi4(), rd, shift.lo4(), rm));
}
void mvn(RegisterID rd, RegisterID rm)
{
if (!((rd | rm) & 8))
m_formatter.oneWordOp10Reg3Reg3(OP_MVN_reg_T1, rm, rd);
else
mvn(rd, rm, ShiftTypeAndAmount());
}
void neg(RegisterID rd, RegisterID rm)
{
ARMThumbImmediate zero = ARMThumbImmediate::makeUInt12(0);
sub(rd, zero, rm);
}
void orr(RegisterID rd, RegisterID rn, ARMThumbImmediate imm)
{
ASSERT(!BadReg(rd));
ASSERT(!BadReg(rn));
ASSERT(imm.isEncodedImm());
m_formatter.twoWordOp5i6Imm4Reg4EncodedImm(OP_ORR_imm_T1, rn, rd, imm);
}
void orr(RegisterID rd, RegisterID rn, RegisterID rm, ShiftTypeAndAmount shift)
{
ASSERT(!BadReg(rd));
ASSERT(!BadReg(rn));
ASSERT(!BadReg(rm));
m_formatter.twoWordOp12Reg4FourFours(OP_ORR_reg_T2, rn, FourFours(shift.hi4(), rd, shift.lo4(), rm));
}
void orr(RegisterID rd, RegisterID rn, RegisterID rm)
{
if ((rd == rn) && !((rd | rm) & 8))
m_formatter.oneWordOp10Reg3Reg3(OP_ORR_reg_T1, rm, rd);
else if ((rd == rm) && !((rd | rn) & 8))
m_formatter.oneWordOp10Reg3Reg3(OP_ORR_reg_T1, rn, rd);
else
orr(rd, rn, rm, ShiftTypeAndAmount());
}
void orr_S(RegisterID rd, RegisterID rn, RegisterID rm, ShiftTypeAndAmount shift)
{
ASSERT(!BadReg(rd));
ASSERT(!BadReg(rn));
ASSERT(!BadReg(rm));
m_formatter.twoWordOp12Reg4FourFours(OP_ORR_S_reg_T2, rn, FourFours(shift.hi4(), rd, shift.lo4(), rm));
}
void orr_S(RegisterID rd, RegisterID rn, RegisterID rm)
{
if ((rd == rn) && !((rd | rm) & 8))
m_formatter.oneWordOp10Reg3Reg3(OP_ORR_reg_T1, rm, rd);
else if ((rd == rm) && !((rd | rn) & 8))
m_formatter.oneWordOp10Reg3Reg3(OP_ORR_reg_T1, rn, rd);
else
orr_S(rd, rn, rm, ShiftTypeAndAmount());
}
void ror(RegisterID rd, RegisterID rm, int32_t shiftAmount)
{
ASSERT(!BadReg(rd));
ASSERT(!BadReg(rm));
ShiftTypeAndAmount shift(SRType_ROR, shiftAmount);
m_formatter.twoWordOp16FourFours(OP_ROR_imm_T1, FourFours(shift.hi4(), rd, shift.lo4(), rm));
}
void ror(RegisterID rd, RegisterID rn, RegisterID rm)
{
ASSERT(!BadReg(rd));
ASSERT(!BadReg(rn));
ASSERT(!BadReg(rm));
m_formatter.twoWordOp12Reg4FourFours(OP_ROR_reg_T2, rn, FourFours(0xf, rd, 0, rm));
}
void smull(RegisterID rdLo, RegisterID rdHi, RegisterID rn, RegisterID rm)
{
ASSERT(!BadReg(rdLo));
ASSERT(!BadReg(rdHi));
ASSERT(!BadReg(rn));
ASSERT(!BadReg(rm));
ASSERT(rdLo != rdHi);
m_formatter.twoWordOp12Reg4FourFours(OP_SMULL_T1, rn, FourFours(rdLo, rdHi, 0, rm));
}
// rt == ARMRegisters::pc only allowed if last instruction in IT (if then) block.
void str(RegisterID rt, RegisterID rn, ARMThumbImmediate imm)
{
ASSERT(rt != ARMRegisters::pc);
ASSERT(rn != ARMRegisters::pc);
ASSERT(imm.isUInt12());
if (!((rt | rn) & 8) && imm.isUInt7())
m_formatter.oneWordOp5Imm5Reg3Reg3(OP_STR_imm_T1, imm.getUInt7() >> 2, rn, rt);
else if ((rn == ARMRegisters::sp) && !(rt & 8) && imm.isUInt10())
m_formatter.oneWordOp5Reg3Imm8(OP_STR_imm_T2, rt, imm.getUInt10() >> 2);
else
m_formatter.twoWordOp12Reg4Reg4Imm12(OP_STR_imm_T3, rn, rt, imm.getUInt12());
}
// If index is set, this is a regular offset or a pre-indexed store;
// if index is not set then is is a post-index store.
//
// If wback is set rn is updated - this is a pre or post index store,
// if wback is not set this is a regular offset memory access.
//
// (-255 <= offset <= 255)
// _reg = REG[rn]
// _tmp = _reg + offset
// MEM[index ? _tmp : _reg] = REG[rt]
// if (wback) REG[rn] = _tmp
void str(RegisterID rt, RegisterID rn, int offset, bool index, bool wback)
{
ASSERT(rt != ARMRegisters::pc);
ASSERT(rn != ARMRegisters::pc);
ASSERT(index || wback);
ASSERT(!wback | (rt != rn));
bool add = true;
if (offset < 0) {
add = false;
offset = -offset;
}
ASSERT((offset & ~0xff) == 0);
offset |= (wback << 8);
offset |= (add << 9);
offset |= (index << 10);
offset |= (1 << 11);
m_formatter.twoWordOp12Reg4Reg4Imm12(OP_STR_imm_T4, rn, rt, offset);
}
// rt == ARMRegisters::pc only allowed if last instruction in IT (if then) block.
void str(RegisterID rt, RegisterID rn, RegisterID rm, unsigned shift=0)
{
ASSERT(rn != ARMRegisters::pc);
ASSERT(!BadReg(rm));
ASSERT(shift <= 3);
if (!shift && !((rt | rn | rm) & 8))
m_formatter.oneWordOp7Reg3Reg3Reg3(OP_STR_reg_T1, rm, rn, rt);
else
m_formatter.twoWordOp12Reg4FourFours(OP_STR_reg_T2, rn, FourFours(rt, 0, shift, rm));
}
void sub(RegisterID rd, RegisterID rn, ARMThumbImmediate imm)
{
// Rd can only be SP if Rn is also SP.
ASSERT((rd != ARMRegisters::sp) || (rn == ARMRegisters::sp));
ASSERT(rd != ARMRegisters::pc);
ASSERT(rn != ARMRegisters::pc);
ASSERT(imm.isValid());
if ((rn == ARMRegisters::sp) && (rd == ARMRegisters::sp) && imm.isUInt9()) {
m_formatter.oneWordOp9Imm7(OP_SUB_SP_imm_T1, imm.getUInt9() >> 2);
return;
} else if (!((rd | rn) & 8)) {
if (imm.isUInt3()) {
m_formatter.oneWordOp7Reg3Reg3Reg3(OP_SUB_imm_T1, (RegisterID)imm.getUInt3(), rn, rd);
return;
} else if ((rd == rn) && imm.isUInt8()) {
m_formatter.oneWordOp5Reg3Imm8(OP_SUB_imm_T2, rd, imm.getUInt8());
return;
}
}
if (imm.isEncodedImm())
m_formatter.twoWordOp5i6Imm4Reg4EncodedImm(OP_SUB_imm_T3, rn, rd, imm);
else {
ASSERT(imm.isUInt12());
m_formatter.twoWordOp5i6Imm4Reg4EncodedImm(OP_SUB_imm_T4, rn, rd, imm);
}
}
void sub(RegisterID rd, ARMThumbImmediate imm, RegisterID rn)
{
ASSERT(rd != ARMRegisters::pc);
ASSERT(rn != ARMRegisters::pc);
ASSERT(imm.isValid());
ASSERT(imm.isUInt12());
if (!((rd | rn) & 8) && !imm.getUInt12())
m_formatter.oneWordOp10Reg3Reg3(OP_RSB_imm_T1, rn, rd);
else
m_formatter.twoWordOp5i6Imm4Reg4EncodedImm(OP_RSB_imm_T2, rn, rd, imm);
}
void sub(RegisterID rd, RegisterID rn, RegisterID rm, ShiftTypeAndAmount shift)
{
ASSERT((rd != ARMRegisters::sp) || (rn == ARMRegisters::sp));
ASSERT(rd != ARMRegisters::pc);
ASSERT(rn != ARMRegisters::pc);
ASSERT(!BadReg(rm));
m_formatter.twoWordOp12Reg4FourFours(OP_SUB_reg_T2, rn, FourFours(shift.hi4(), rd, shift.lo4(), rm));
}
// NOTE: In an IT block, add doesn't modify the flags register.
void sub(RegisterID rd, RegisterID rn, RegisterID rm)
{
if (!((rd | rn | rm) & 8))
m_formatter.oneWordOp7Reg3Reg3Reg3(OP_SUB_reg_T1, rm, rn, rd);
else
sub(rd, rn, rm, ShiftTypeAndAmount());
}
// Not allowed in an IT (if then) block.
void sub_S(RegisterID rd, RegisterID rn, ARMThumbImmediate imm)
{
// Rd can only be SP if Rn is also SP.
ASSERT((rd != ARMRegisters::sp) || (rn == ARMRegisters::sp));
ASSERT(rd != ARMRegisters::pc);
ASSERT(rn != ARMRegisters::pc);
ASSERT(imm.isValid());
if ((rn == ARMRegisters::sp) && (rd == ARMRegisters::sp) && imm.isUInt9()) {
m_formatter.oneWordOp9Imm7(OP_SUB_SP_imm_T1, imm.getUInt9() >> 2);
return;
} else if (!((rd | rn) & 8)) {
if (imm.isUInt3()) {
m_formatter.oneWordOp7Reg3Reg3Reg3(OP_SUB_imm_T1, (RegisterID)imm.getUInt3(), rn, rd);
return;
} else if ((rd == rn) && imm.isUInt8()) {
m_formatter.oneWordOp5Reg3Imm8(OP_SUB_imm_T2, rd, imm.getUInt8());
return;
}
}
m_formatter.twoWordOp5i6Imm4Reg4EncodedImm(OP_SUB_S_imm_T3, rn, rd, imm);
}
// Not allowed in an IT (if then) block?
void sub_S(RegisterID rd, RegisterID rn, RegisterID rm, ShiftTypeAndAmount shift)
{
ASSERT((rd != ARMRegisters::sp) || (rn == ARMRegisters::sp));
ASSERT(rd != ARMRegisters::pc);
ASSERT(rn != ARMRegisters::pc);
ASSERT(!BadReg(rm));
m_formatter.twoWordOp12Reg4FourFours(OP_SUB_S_reg_T2, rn, FourFours(shift.hi4(), rd, shift.lo4(), rm));
}
// Not allowed in an IT (if then) block.
void sub_S(RegisterID rd, RegisterID rn, RegisterID rm)
{
if (!((rd | rn | rm) & 8))
m_formatter.oneWordOp7Reg3Reg3Reg3(OP_SUB_reg_T1, rm, rn, rd);
else
sub_S(rd, rn, rm, ShiftTypeAndAmount());
}
void tst(RegisterID rn, ARMThumbImmediate imm)
{
ASSERT(!BadReg(rn));
ASSERT(imm.isEncodedImm());
m_formatter.twoWordOp5i6Imm4Reg4EncodedImm(OP_TST_imm, rn, (RegisterID)0xf, imm);
}
void tst(RegisterID rn, RegisterID rm, ShiftTypeAndAmount shift)
{
ASSERT(!BadReg(rn));
ASSERT(!BadReg(rm));
m_formatter.twoWordOp12Reg4FourFours(OP_TST_reg_T2, rn, FourFours(shift.hi4(), 0xf, shift.lo4(), rm));
}
void tst(RegisterID rn, RegisterID rm)
{
if ((rn | rm) & 8)
tst(rn, rm, ShiftTypeAndAmount());
else
m_formatter.oneWordOp10Reg3Reg3(OP_TST_reg_T1, rm, rn);
}
void vadd_F64(FPDoubleRegisterID rd, FPDoubleRegisterID rn, FPDoubleRegisterID rm)
{
m_formatter.vfpOp(OP_VADD_T2, OP_VADD_T2b, true, rn, rd, rm);
}
void vcmp_F64(FPDoubleRegisterID rd, FPDoubleRegisterID rm)
{
m_formatter.vfpOp(OP_VCMP, OP_VCMPb, true, VFPOperand(4), rd, rm);
}
void vcmpz_F64(FPDoubleRegisterID rd)
{
m_formatter.vfpOp(OP_VCMP, OP_VCMPb, true, VFPOperand(5), rd, VFPOperand(0));
}
void vcvt_F64_S32(FPDoubleRegisterID rd, FPSingleRegisterID rm)
{
// boolean values are 64bit (toInt, unsigned, roundZero)
m_formatter.vfpOp(OP_VCVT_FPIVFP, OP_VCVT_FPIVFPb, true, vcvtOp(false, false, false), rd, rm);
}
void vcvtr_S32_F64(FPSingleRegisterID rd, FPDoubleRegisterID rm)
{
// boolean values are 64bit (toInt, unsigned, roundZero)
m_formatter.vfpOp(OP_VCVT_FPIVFP, OP_VCVT_FPIVFPb, true, vcvtOp(true, false, true), rd, rm);
}
void vdiv_F64(FPDoubleRegisterID rd, FPDoubleRegisterID rn, FPDoubleRegisterID rm)
{
m_formatter.vfpOp(OP_VDIV, OP_VDIVb, true, rn, rd, rm);
}
void vldr(FPDoubleRegisterID rd, RegisterID rn, int32_t imm)
{
m_formatter.vfpMemOp(OP_VLDR, OP_VLDRb, true, rn, rd, imm);
}
void vmov(RegisterID rd, FPSingleRegisterID rn)
{
ASSERT(!BadReg(rd));
m_formatter.vfpOp(OP_VMOV_CtoS, OP_VMOV_CtoSb, false, rn, rd, VFPOperand(0));
}
void vmov(FPSingleRegisterID rd, RegisterID rn)
{
ASSERT(!BadReg(rn));
m_formatter.vfpOp(OP_VMOV_StoC, OP_VMOV_StoCb, false, rd, rn, VFPOperand(0));
}
void vmrs(RegisterID reg = ARMRegisters::pc)
{
ASSERT(reg != ARMRegisters::sp);
m_formatter.vfpOp(OP_VMRS, OP_VMRSb, false, VFPOperand(1), VFPOperand(0x10 | reg), VFPOperand(0));
}
void vmul_F64(FPDoubleRegisterID rd, FPDoubleRegisterID rn, FPDoubleRegisterID rm)
{
m_formatter.vfpOp(OP_VMUL_T2, OP_VMUL_T2b, true, rn, rd, rm);
}
void vstr(FPDoubleRegisterID rd, RegisterID rn, int32_t imm)
{
m_formatter.vfpMemOp(OP_VSTR, OP_VSTRb, true, rn, rd, imm);
}
void vsub_F64(FPDoubleRegisterID rd, FPDoubleRegisterID rn, FPDoubleRegisterID rm)
{
m_formatter.vfpOp(OP_VSUB_T2, OP_VSUB_T2b, true, rn, rd, rm);
}
JmpDst label()
{
return JmpDst(m_formatter.size());
}
JmpDst align(int alignment)
{
while (!m_formatter.isAligned(alignment))
bkpt();
return label();
}
static void* getRelocatedAddress(void* code, JmpSrc jump)
{
ASSERT(jump.m_offset != -1);
return reinterpret_cast<void*>(reinterpret_cast<ptrdiff_t>(code) + jump.m_offset);
}
static void* getRelocatedAddress(void* code, JmpDst destination)
{
ASSERT(destination.m_offset != -1);
return reinterpret_cast<void*>(reinterpret_cast<ptrdiff_t>(code) + destination.m_offset);
}
static int getDifferenceBetweenLabels(JmpDst src, JmpDst dst)
{
return dst.m_offset - src.m_offset;
}
static int getDifferenceBetweenLabels(JmpDst src, JmpSrc dst)
{
return dst.m_offset - src.m_offset;
}
static int getDifferenceBetweenLabels(JmpSrc src, JmpDst dst)
{
return dst.m_offset - src.m_offset;
}
int executableOffsetFor(int location)
{
if (!location)
return 0;
return static_cast<int32_t*>(m_formatter.data())[location / sizeof(int32_t) - 1];
}
int jumpSizeDelta(JumpType jumpType, JumpLinkType jumpLinkType) { return JumpPaddingSizes[jumpType] - JumpSizes[jumpLinkType]; }
// Assembler admin methods:
size_t size() const
{
return m_formatter.size();
}
static bool linkRecordSourceComparator(const LinkRecord& a, const LinkRecord& b)
{
return a.from() < b.from();
}
bool canCompact(JumpType jumpType)
{
// The following cannot be compacted:
// JumpFixed: represents custom jump sequence
// JumpNoConditionFixedSize: represents unconditional jump that must remain a fixed size
// JumpConditionFixedSize: represents conditional jump that must remain a fixed size
return (jumpType == JumpNoCondition) || (jumpType == JumpCondition);
}
JumpLinkType computeJumpType(JumpType jumpType, const uint8_t* from, const uint8_t* to)
{
if (jumpType == JumpFixed)
return LinkInvalid;
// for patchable jump we must leave space for the longest code sequence
if (jumpType == JumpNoConditionFixedSize)
return LinkBX;
if (jumpType == JumpConditionFixedSize)
return LinkConditionalBX;
const int paddingSize = JumpPaddingSizes[jumpType];
bool mayTriggerErrata = false;
if (jumpType == JumpCondition) {
// 2-byte conditional T1
const uint16_t* jumpT1Location = reinterpret_cast<const uint16_t*>(from - (paddingSize - JumpSizes[LinkJumpT1]));
if (canBeJumpT1(jumpT1Location, to))
return LinkJumpT1;
// 4-byte conditional T3
const uint16_t* jumpT3Location = reinterpret_cast<const uint16_t*>(from - (paddingSize - JumpSizes[LinkJumpT3]));
if (canBeJumpT3(jumpT3Location, to, mayTriggerErrata)) {
if (!mayTriggerErrata)
return LinkJumpT3;
}
// 4-byte conditional T4 with IT
const uint16_t* conditionalJumpT4Location =
reinterpret_cast<const uint16_t*>(from - (paddingSize - JumpSizes[LinkConditionalJumpT4]));
if (canBeJumpT4(conditionalJumpT4Location, to, mayTriggerErrata)) {
if (!mayTriggerErrata)
return LinkConditionalJumpT4;
}
} else {
// 2-byte unconditional T2
const uint16_t* jumpT2Location = reinterpret_cast<const uint16_t*>(from - (paddingSize - JumpSizes[LinkJumpT2]));
if (canBeJumpT2(jumpT2Location, to))
return LinkJumpT2;
// 4-byte unconditional T4
const uint16_t* jumpT4Location = reinterpret_cast<const uint16_t*>(from - (paddingSize - JumpSizes[LinkJumpT4]));
if (canBeJumpT4(jumpT4Location, to, mayTriggerErrata)) {
if (!mayTriggerErrata)
return LinkJumpT4;
}
// use long jump sequence
return LinkBX;
}
ASSERT(jumpType == JumpCondition);
return LinkConditionalBX;
}
JumpLinkType computeJumpType(LinkRecord& record, const uint8_t* from, const uint8_t* to)
{
JumpLinkType linkType = computeJumpType(record.type(), from, to);
record.setLinkType(linkType);
return linkType;
}
void recordLinkOffsets(int32_t regionStart, int32_t regionEnd, int32_t offset)
{
int32_t ptr = regionStart / sizeof(int32_t);
const int32_t end = regionEnd / sizeof(int32_t);
int32_t* offsets = static_cast<int32_t*>(m_formatter.data());
while (ptr < end)
offsets[ptr++] = offset;
}
Vector<LinkRecord>& jumpsToLink()
{
std::sort(m_jumpsToLink.begin(), m_jumpsToLink.end(), linkRecordSourceComparator);
return m_jumpsToLink;
}
void link(LinkRecord& record, uint8_t* from, uint8_t* to)
{
switch (record.linkType()) {
case LinkJumpT1:
linkJumpT1(record.condition(), reinterpret_cast<uint16_t*>(from), to);
break;
case LinkJumpT2:
linkJumpT2(reinterpret_cast<uint16_t*>(from), to);
break;
case LinkJumpT3:
linkJumpT3(record.condition(), reinterpret_cast<uint16_t*>(from), to);
break;
case LinkJumpT4:
linkJumpT4(reinterpret_cast<uint16_t*>(from), to);
break;
case LinkConditionalJumpT4:
linkConditionalJumpT4(record.condition(), reinterpret_cast<uint16_t*>(from), to);
break;
case LinkConditionalBX:
linkConditionalBX(record.condition(), reinterpret_cast<uint16_t*>(from), to);
break;
case LinkBX:
linkBX(reinterpret_cast<uint16_t*>(from), to);
break;
default:
ASSERT_NOT_REACHED();
break;
}
}
void* unlinkedCode() { return m_formatter.data(); }
static unsigned getCallReturnOffset(JmpSrc call)
{
ASSERT(call.m_offset >= 0);
return call.m_offset;
}
// Linking & patching:
//
// 'link' and 'patch' methods are for use on unprotected code - such as the code
// within the AssemblerBuffer, and code being patched by the patch buffer. Once
// code has been finalized it is (platform support permitting) within a non-
// writable region of memory; to modify the code in an execute-only execuable
// pool the 'repatch' and 'relink' methods should be used.
void linkJump(JmpSrc from, JmpDst to)
{
ASSERT(to.m_offset != -1);
ASSERT(from.m_offset != -1);
m_jumpsToLink.append(LinkRecord(from.m_offset, to.m_offset, from.m_type, from.m_condition));
}
static void linkJump(void* code, JmpSrc from, void* to)
{
ASSERT(from.m_offset != -1);
uint16_t* location = reinterpret_cast<uint16_t*>(reinterpret_cast<intptr_t>(code) + from.m_offset);
linkJumpAbsolute(location, to);
}
// bah, this mathod should really be static, since it is used by the LinkBuffer.
// return a bool saying whether the link was successful?
static void linkCall(void* code, JmpSrc from, void* to)
{
ASSERT(!(reinterpret_cast<intptr_t>(code) & 1));
ASSERT(from.m_offset != -1);
ASSERT(reinterpret_cast<intptr_t>(to) & 1);
setPointer(reinterpret_cast<uint16_t*>(reinterpret_cast<intptr_t>(code) + from.m_offset) - 1, to);
}
static void linkPointer(void* code, JmpDst where, void* value)
{
setPointer(reinterpret_cast<char*>(code) + where.m_offset, value);
}
static void relinkJump(void* from, void* to)
{
ASSERT(!(reinterpret_cast<intptr_t>(from) & 1));
ASSERT(!(reinterpret_cast<intptr_t>(to) & 1));
linkJumpAbsolute(reinterpret_cast<uint16_t*>(from), to);
ExecutableAllocator::cacheFlush(reinterpret_cast<uint16_t*>(from) - 5, 5 * sizeof(uint16_t));
}
static void relinkCall(void* from, void* to)
{
ASSERT(!(reinterpret_cast<intptr_t>(from) & 1));
ASSERT(reinterpret_cast<intptr_t>(to) & 1);
setPointer(reinterpret_cast<uint16_t*>(from) - 1, to);
}
static void repatchInt32(void* where, int32_t value)
{
ASSERT(!(reinterpret_cast<intptr_t>(where) & 1));
setInt32(where, value);
}
static void repatchPointer(void* where, void* value)
{
ASSERT(!(reinterpret_cast<intptr_t>(where) & 1));
setPointer(where, value);
}
private:
// VFP operations commonly take one or more 5-bit operands, typically representing a
// floating point register number. This will commonly be encoded in the instruction
// in two parts, with one single bit field, and one 4-bit field. In the case of
// double precision operands the high bit of the register number will be encoded
// separately, and for single precision operands the high bit of the register number
// will be encoded individually.
// VFPOperand encapsulates a 5-bit VFP operand, with bits 0..3 containing the 4-bit
// field to be encoded together in the instruction (the low 4-bits of a double
// register number, or the high 4-bits of a single register number), and bit 4
// contains the bit value to be encoded individually.
struct VFPOperand {
explicit VFPOperand(uint32_t value)
: m_value(value)
{
ASSERT(!(m_value & ~0x1f));
}
VFPOperand(FPDoubleRegisterID reg)
: m_value(reg)
{
}
VFPOperand(RegisterID reg)
: m_value(reg)
{
}
VFPOperand(FPSingleRegisterID reg)
: m_value(((reg & 1) << 4) | (reg >> 1)) // rotate the lowest bit of 'reg' to the top.
{
}
uint32_t bits1()
{
return m_value >> 4;
}
uint32_t bits4()
{
return m_value & 0xf;
}
uint32_t m_value;
};
VFPOperand vcvtOp(bool toInteger, bool isUnsigned, bool isRoundZero)
{
// Cannot specify rounding when converting to float.
ASSERT(toInteger || !isRoundZero);
uint32_t op = 0x8;
if (toInteger) {
// opc2 indicates both toInteger & isUnsigned.
op |= isUnsigned ? 0x4 : 0x5;
// 'op' field in instruction is isRoundZero
if (isRoundZero)
op |= 0x10;
} else {
// 'op' field in instruction is isUnsigned
if (!isUnsigned)
op |= 0x10;
}
return VFPOperand(op);
}
static void setInt32(void* code, uint32_t value)
{
uint16_t* location = reinterpret_cast<uint16_t*>(code);
ASSERT(isMOV_imm_T3(location - 4) && isMOVT(location - 2));
ARMThumbImmediate lo16 = ARMThumbImmediate::makeUInt16(static_cast<uint16_t>(value));
ARMThumbImmediate hi16 = ARMThumbImmediate::makeUInt16(static_cast<uint16_t>(value >> 16));
location[-4] = twoWordOp5i6Imm4Reg4EncodedImmFirst(OP_MOV_imm_T3, lo16);
location[-3] = twoWordOp5i6Imm4Reg4EncodedImmSecond((location[-3] >> 8) & 0xf, lo16);
location[-2] = twoWordOp5i6Imm4Reg4EncodedImmFirst(OP_MOVT, hi16);
location[-1] = twoWordOp5i6Imm4Reg4EncodedImmSecond((location[-1] >> 8) & 0xf, hi16);
ExecutableAllocator::cacheFlush(location - 4, 4 * sizeof(uint16_t));
}
static void setPointer(void* code, void* value)
{
setInt32(code, reinterpret_cast<uint32_t>(value));
}
static bool isB(void* address)
{
uint16_t* instruction = static_cast<uint16_t*>(address);
return ((instruction[0] & 0xf800) == OP_B_T4a) && ((instruction[1] & 0xd000) == OP_B_T4b);
}
static bool isBX(void* address)
{
uint16_t* instruction = static_cast<uint16_t*>(address);
return (instruction[0] & 0xff87) == OP_BX;
}
static bool isMOV_imm_T3(void* address)
{
uint16_t* instruction = static_cast<uint16_t*>(address);
return ((instruction[0] & 0xFBF0) == OP_MOV_imm_T3) && ((instruction[1] & 0x8000) == 0);
}
static bool isMOVT(void* address)
{
uint16_t* instruction = static_cast<uint16_t*>(address);
return ((instruction[0] & 0xFBF0) == OP_MOVT) && ((instruction[1] & 0x8000) == 0);
}
static bool isNOP_T1(void* address)
{
uint16_t* instruction = static_cast<uint16_t*>(address);
return instruction[0] == OP_NOP_T1;
}
static bool isNOP_T2(void* address)
{
uint16_t* instruction = static_cast<uint16_t*>(address);
return (instruction[0] == OP_NOP_T2a) && (instruction[1] == OP_NOP_T2b);
}
static bool canBeJumpT1(const uint16_t* instruction, const void* target)
{
ASSERT(!(reinterpret_cast<intptr_t>(instruction) & 1));
ASSERT(!(reinterpret_cast<intptr_t>(target) & 1));
intptr_t relative = reinterpret_cast<intptr_t>(target) - (reinterpret_cast<intptr_t>(instruction));
// It does not appear to be documented in the ARM ARM (big surprise), but
// for OP_B_T1 the branch displacement encoded in the instruction is 2
// less than the actual displacement.
relative -= 2;
return ((relative << 23) >> 23) == relative;
}
static bool canBeJumpT2(const uint16_t* instruction, const void* target)
{
ASSERT(!(reinterpret_cast<intptr_t>(instruction) & 1));
ASSERT(!(reinterpret_cast<intptr_t>(target) & 1));
intptr_t relative = reinterpret_cast<intptr_t>(target) - (reinterpret_cast<intptr_t>(instruction));
// It does not appear to be documented in the ARM ARM (big surprise), but
// for OP_B_T2 the branch displacement encoded in the instruction is 2
// less than the actual displacement.
relative -= 2;
return ((relative << 20) >> 20) == relative;
}
static bool canBeJumpT3(const uint16_t* instruction, const void* target, bool& mayTriggerErrata)
{
ASSERT(!(reinterpret_cast<intptr_t>(instruction) & 1));
ASSERT(!(reinterpret_cast<intptr_t>(target) & 1));
intptr_t relative = reinterpret_cast<intptr_t>(target) - (reinterpret_cast<intptr_t>(instruction));
// From Cortex-A8 errata:
// If the 32-bit Thumb-2 branch instruction spans two 4KiB regions and
// the target of the branch falls within the first region it is
// possible for the processor to incorrectly determine the branch
// instruction, and it is also possible in some cases for the processor
// to enter a deadlock state.
// The instruction is spanning two pages if it ends at an address ending 0x002
bool spansTwo4K = ((reinterpret_cast<intptr_t>(instruction) & 0xfff) == 0x002);
mayTriggerErrata = spansTwo4K;
// The target is in the first page if the jump branch back by [3..0x1002] bytes
bool targetInFirstPage = (relative >= -0x1002) && (relative < -2);
bool wouldTriggerA8Errata = spansTwo4K && targetInFirstPage;
return ((relative << 11) >> 11) == relative && !wouldTriggerA8Errata;
}
static bool canBeJumpT4(const uint16_t* instruction, const void* target, bool& mayTriggerErrata)
{
ASSERT(!(reinterpret_cast<intptr_t>(instruction) & 1));
ASSERT(!(reinterpret_cast<intptr_t>(target) & 1));
intptr_t relative = reinterpret_cast<intptr_t>(target) - (reinterpret_cast<intptr_t>(instruction));
// From Cortex-A8 errata:
// If the 32-bit Thumb-2 branch instruction spans two 4KiB regions and
// the target of the branch falls within the first region it is
// possible for the processor to incorrectly determine the branch
// instruction, and it is also possible in some cases for the processor
// to enter a deadlock state.
// The instruction is spanning two pages if it ends at an address ending 0x002
bool spansTwo4K = ((reinterpret_cast<intptr_t>(instruction) & 0xfff) == 0x002);
mayTriggerErrata = spansTwo4K;
// The target is in the first page if the jump branch back by [3..0x1002] bytes
bool targetInFirstPage = (relative >= -0x1002) && (relative < -2);
bool wouldTriggerA8Errata = spansTwo4K && targetInFirstPage;
return ((relative << 7) >> 7) == relative && !wouldTriggerA8Errata;
}
void linkJumpT1(Condition cond, uint16_t* instruction, void* target)
{
// FIMXE: this should be up in the MacroAssembler layer. :-(
ASSERT(!(reinterpret_cast<intptr_t>(instruction) & 1));
ASSERT(!(reinterpret_cast<intptr_t>(target) & 1));
ASSERT(canBeJumpT1(instruction, target));
intptr_t relative = reinterpret_cast<intptr_t>(target) - (reinterpret_cast<intptr_t>(instruction));
// It does not appear to be documented in the ARM ARM (big surprise), but
// for OP_B_T1 the branch displacement encoded in the instruction is 2
// less than the actual displacement.
relative -= 2;
// All branch offsets should be an even distance.
ASSERT(!(relative & 1));
instruction[-1] = OP_B_T1 | ((cond & 0xf) << 8) | ((relative & 0x1fe) >> 1);
}
static void linkJumpT2(uint16_t* instruction, void* target)
{
// FIMXE: this should be up in the MacroAssembler layer. :-(
ASSERT(!(reinterpret_cast<intptr_t>(instruction) & 1));
ASSERT(!(reinterpret_cast<intptr_t>(target) & 1));
ASSERT(canBeJumpT2(instruction, target));
intptr_t relative = reinterpret_cast<intptr_t>(target) - (reinterpret_cast<intptr_t>(instruction));
// It does not appear to be documented in the ARM ARM (big surprise), but
// for OP_B_T2 the branch displacement encoded in the instruction is 2
// less than the actual displacement.
relative -= 2;
// All branch offsets should be an even distance.
ASSERT(!(relative & 1));
instruction[-1] = OP_B_T2 | ((relative & 0xffe) >> 1);
}
void linkJumpT3(Condition cond, uint16_t* instruction, void* target)
{
// FIMXE: this should be up in the MacroAssembler layer. :-(
ASSERT(!(reinterpret_cast<intptr_t>(instruction) & 1));
ASSERT(!(reinterpret_cast<intptr_t>(target) & 1));
bool scratch;
UNUSED_PARAM(scratch);
ASSERT(canBeJumpT3(instruction, target, scratch));
intptr_t relative = reinterpret_cast<intptr_t>(target) - (reinterpret_cast<intptr_t>(instruction));
// All branch offsets should be an even distance.
ASSERT(!(relative & 1));
instruction[-2] = OP_B_T3a | ((relative & 0x100000) >> 10) | ((cond & 0xf) << 6) | ((relative & 0x3f000) >> 12);
instruction[-1] = OP_B_T3b | ((relative & 0x80000) >> 8) | ((relative & 0x40000) >> 5) | ((relative & 0xffe) >> 1);
}
static void linkJumpT4(uint16_t* instruction, void* target)
{
// FIMXE: this should be up in the MacroAssembler layer. :-(
ASSERT(!(reinterpret_cast<intptr_t>(instruction) & 1));
ASSERT(!(reinterpret_cast<intptr_t>(target) & 1));
bool scratch;
UNUSED_PARAM(scratch);
ASSERT(canBeJumpT4(instruction, target, scratch));
intptr_t relative = reinterpret_cast<intptr_t>(target) - (reinterpret_cast<intptr_t>(instruction));
// ARM encoding for the top two bits below the sign bit is 'peculiar'.
if (relative >= 0)
relative ^= 0xC00000;
// All branch offsets should be an even distance.
ASSERT(!(relative & 1));
instruction[-2] = OP_B_T4a | ((relative & 0x1000000) >> 14) | ((relative & 0x3ff000) >> 12);
instruction[-1] = OP_B_T4b | ((relative & 0x800000) >> 10) | ((relative & 0x400000) >> 11) | ((relative & 0xffe) >> 1);
}
void linkConditionalJumpT4(Condition cond, uint16_t* instruction, void* target)
{
// FIMXE: this should be up in the MacroAssembler layer. :-(
ASSERT(!(reinterpret_cast<intptr_t>(instruction) & 1));
ASSERT(!(reinterpret_cast<intptr_t>(target) & 1));
instruction[-3] = ifThenElse(cond) | OP_IT;
linkJumpT4(instruction, target);
}
static void linkBX(uint16_t* instruction, void* target)
{
// FIMXE: this should be up in the MacroAssembler layer. :-(
ASSERT(!(reinterpret_cast<intptr_t>(instruction) & 1));
ASSERT(!(reinterpret_cast<intptr_t>(target) & 1));
const uint16_t JUMP_TEMPORARY_REGISTER = ARMRegisters::ip;
ARMThumbImmediate lo16 = ARMThumbImmediate::makeUInt16(static_cast<uint16_t>(reinterpret_cast<uint32_t>(target) + 1));
ARMThumbImmediate hi16 = ARMThumbImmediate::makeUInt16(static_cast<uint16_t>(reinterpret_cast<uint32_t>(target) >> 16));
instruction[-5] = twoWordOp5i6Imm4Reg4EncodedImmFirst(OP_MOV_imm_T3, lo16);
instruction[-4] = twoWordOp5i6Imm4Reg4EncodedImmSecond(JUMP_TEMPORARY_REGISTER, lo16);
instruction[-3] = twoWordOp5i6Imm4Reg4EncodedImmFirst(OP_MOVT, hi16);
instruction[-2] = twoWordOp5i6Imm4Reg4EncodedImmSecond(JUMP_TEMPORARY_REGISTER, hi16);
instruction[-1] = OP_BX | (JUMP_TEMPORARY_REGISTER << 3);
}
void linkConditionalBX(Condition cond, uint16_t* instruction, void* target)
{
// FIMXE: this should be up in the MacroAssembler layer. :-(
ASSERT(!(reinterpret_cast<intptr_t>(instruction) & 1));
ASSERT(!(reinterpret_cast<intptr_t>(target) & 1));
linkBX(instruction, target);
instruction[-6] = ifThenElse(cond, true, true) | OP_IT;
}
static void linkJumpAbsolute(uint16_t* instruction, void* target)
{
// FIMXE: this should be up in the MacroAssembler layer. :-(
ASSERT(!(reinterpret_cast<intptr_t>(instruction) & 1));
ASSERT(!(reinterpret_cast<intptr_t>(target) & 1));
ASSERT((isMOV_imm_T3(instruction - 5) && isMOVT(instruction - 3) && isBX(instruction - 1))
|| (isNOP_T1(instruction - 5) && isNOP_T2(instruction - 4) && isB(instruction - 2)));
bool scratch;
if (canBeJumpT4(instruction, target, scratch)) {
// There may be a better way to fix this, but right now put the NOPs first, since in the
// case of an conditional branch this will be coming after an ITTT predicating *three*
// instructions! Looking backwards to modify the ITTT to an IT is not easy, due to
// variable wdith encoding - the previous instruction might *look* like an ITTT but
// actually be the second half of a 2-word op.
instruction[-5] = OP_NOP_T1;
instruction[-4] = OP_NOP_T2a;
instruction[-3] = OP_NOP_T2b;
linkJumpT4(instruction, target);
} else {
const uint16_t JUMP_TEMPORARY_REGISTER = ARMRegisters::ip;
ARMThumbImmediate lo16 = ARMThumbImmediate::makeUInt16(static_cast<uint16_t>(reinterpret_cast<uint32_t>(target) + 1));
ARMThumbImmediate hi16 = ARMThumbImmediate::makeUInt16(static_cast<uint16_t>(reinterpret_cast<uint32_t>(target) >> 16));
instruction[-5] = twoWordOp5i6Imm4Reg4EncodedImmFirst(OP_MOV_imm_T3, lo16);
instruction[-4] = twoWordOp5i6Imm4Reg4EncodedImmSecond(JUMP_TEMPORARY_REGISTER, lo16);
instruction[-3] = twoWordOp5i6Imm4Reg4EncodedImmFirst(OP_MOVT, hi16);
instruction[-2] = twoWordOp5i6Imm4Reg4EncodedImmSecond(JUMP_TEMPORARY_REGISTER, hi16);
instruction[-1] = OP_BX | (JUMP_TEMPORARY_REGISTER << 3);
}
}
static uint16_t twoWordOp5i6Imm4Reg4EncodedImmFirst(uint16_t op, ARMThumbImmediate imm)
{
return op | (imm.m_value.i << 10) | imm.m_value.imm4;
}
static uint16_t twoWordOp5i6Imm4Reg4EncodedImmSecond(uint16_t rd, ARMThumbImmediate imm)
{
return (imm.m_value.imm3 << 12) | (rd << 8) | imm.m_value.imm8;
}
class ARMInstructionFormatter {
public:
void oneWordOp5Reg3Imm8(OpcodeID op, RegisterID rd, uint8_t imm)
{
m_buffer.putShort(op | (rd << 8) | imm);
}
void oneWordOp5Imm5Reg3Reg3(OpcodeID op, uint8_t imm, RegisterID reg1, RegisterID reg2)
{
m_buffer.putShort(op | (imm << 6) | (reg1 << 3) | reg2);
}
void oneWordOp7Reg3Reg3Reg3(OpcodeID op, RegisterID reg1, RegisterID reg2, RegisterID reg3)
{
m_buffer.putShort(op | (reg1 << 6) | (reg2 << 3) | reg3);
}
void oneWordOp8Imm8(OpcodeID op, uint8_t imm)
{
m_buffer.putShort(op | imm);
}
void oneWordOp8RegReg143(OpcodeID op, RegisterID reg1, RegisterID reg2)
{
m_buffer.putShort(op | ((reg2 & 8) << 4) | (reg1 << 3) | (reg2 & 7));
}
void oneWordOp9Imm7(OpcodeID op, uint8_t imm)
{
m_buffer.putShort(op | imm);
}
void oneWordOp10Reg3Reg3(OpcodeID op, RegisterID reg1, RegisterID reg2)
{
m_buffer.putShort(op | (reg1 << 3) | reg2);
}
void twoWordOp12Reg4FourFours(OpcodeID1 op, RegisterID reg, FourFours ff)
{
m_buffer.putShort(op | reg);
m_buffer.putShort(ff.m_u.value);
}
void twoWordOp16FourFours(OpcodeID1 op, FourFours ff)
{
m_buffer.putShort(op);
m_buffer.putShort(ff.m_u.value);
}
void twoWordOp16Op16(OpcodeID1 op1, OpcodeID2 op2)
{
m_buffer.putShort(op1);
m_buffer.putShort(op2);
}
void twoWordOp5i6Imm4Reg4EncodedImm(OpcodeID1 op, int imm4, RegisterID rd, ARMThumbImmediate imm)
{
ARMThumbImmediate newImm = imm;
newImm.m_value.imm4 = imm4;
m_buffer.putShort(ARMv7Assembler::twoWordOp5i6Imm4Reg4EncodedImmFirst(op, newImm));
m_buffer.putShort(ARMv7Assembler::twoWordOp5i6Imm4Reg4EncodedImmSecond(rd, newImm));
}
void twoWordOp12Reg4Reg4Imm12(OpcodeID1 op, RegisterID reg1, RegisterID reg2, uint16_t imm)
{
m_buffer.putShort(op | reg1);
m_buffer.putShort((reg2 << 12) | imm);
}
// Formats up instructions of the pattern:
// 111111111B11aaaa:bbbb222SA2C2cccc
// Where 1s in the pattern come from op1, 2s in the pattern come from op2, S is the provided size bit.
// Operands provide 5 bit values of the form Aaaaa, Bbbbb, Ccccc.
void vfpOp(OpcodeID1 op1, OpcodeID2 op2, bool size, VFPOperand a, VFPOperand b, VFPOperand c)
{
ASSERT(!(op1 & 0x004f));
ASSERT(!(op2 & 0xf1af));
m_buffer.putShort(op1 | b.bits1() << 6 | a.bits4());
m_buffer.putShort(op2 | b.bits4() << 12 | size << 8 | a.bits1() << 7 | c.bits1() << 5 | c.bits4());
}
// Arm vfp addresses can be offset by a 9-bit ones-comp immediate, left shifted by 2.
// (i.e. +/-(0..255) 32-bit words)
void vfpMemOp(OpcodeID1 op1, OpcodeID2 op2, bool size, RegisterID rn, VFPOperand rd, int32_t imm)
{
bool up = true;
if (imm < 0) {
imm = -imm;
up = false;
}
uint32_t offset = imm;
ASSERT(!(offset & ~0x3fc));
offset >>= 2;
m_buffer.putShort(op1 | (up << 7) | rd.bits1() << 6 | rn);
m_buffer.putShort(op2 | rd.bits4() << 12 | size << 8 | offset);
}
// Administrative methods:
size_t size() const { return m_buffer.size(); }
bool isAligned(int alignment) const { return m_buffer.isAligned(alignment); }
void* data() const { return m_buffer.data(); }
void* executableCopy(ExecutablePool* allocator) { return m_buffer.executableCopy(allocator); }
#ifndef NDEBUG
unsigned debugOffset() { return m_formatter.debugOffset(); }
#endif
private:
AssemblerBuffer m_buffer;
} m_formatter;
Vector<LinkRecord> m_jumpsToLink;
Vector<int32_t> m_offsets;
};
} // namespace JSC
#endif // ENABLE(ASSEMBLER) && CPU(ARM_THUMB2)
#endif // ARMAssembler_h