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// Copyright 2013, ARM Limited
// All rights reserved.
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are met:
//
// * Redistributions of source code must retain the above copyright notice,
// this list of conditions and the following disclaimer.
// * Redistributions in binary form must reproduce the above copyright notice,
// this list of conditions and the following disclaimer in the documentation
// and/or other materials provided with the distribution.
// * Neither the name of ARM Limited nor the names of its contributors may be
// used to endorse or promote products derived from this software without
// specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS CONTRIBUTORS "AS IS" AND
// ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
// WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
// DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE
// FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
// DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
// SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
// CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
// OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
#include "globals.h"
#include "utils.h"
#include "a64/decoder-a64.h"
namespace vixl {
void Decoder::DecodeInstruction(const Instruction *instr) {
if (instr->Bits(28, 27) == 0) {
VisitUnallocated(instr);
} else {
switch (instr->Bits(27, 24)) {
// 0: PC relative addressing.
case 0x0: DecodePCRelAddressing(instr); break;
// 1: Add/sub immediate.
case 0x1: DecodeAddSubImmediate(instr); break;
// A: Logical shifted register.
// Add/sub with carry.
// Conditional compare register.
// Conditional compare immediate.
// Conditional select.
// Data processing 1 source.
// Data processing 2 source.
// B: Add/sub shifted register.
// Add/sub extended register.
// Data processing 3 source.
case 0xA:
case 0xB: DecodeDataProcessing(instr); break;
// 2: Logical immediate.
// Move wide immediate.
case 0x2: DecodeLogical(instr); break;
// 3: Bitfield.
// Extract.
case 0x3: DecodeBitfieldExtract(instr); break;
// 4: Unconditional branch immediate.
// Exception generation.
// Compare and branch immediate.
// 5: Compare and branch immediate.
// Conditional branch.
// System.
// 6,7: Unconditional branch.
// Test and branch immediate.
case 0x4:
case 0x5:
case 0x6:
case 0x7: DecodeBranchSystemException(instr); break;
// 8,9: Load/store register pair post-index.
// Load register literal.
// Load/store register unscaled immediate.
// Load/store register immediate post-index.
// Load/store register immediate pre-index.
// Load/store register offset.
// Load/store exclusive.
// C,D: Load/store register pair offset.
// Load/store register pair pre-index.
// Load/store register unsigned immediate.
// Advanced SIMD.
case 0x8:
case 0x9:
case 0xC:
case 0xD: DecodeLoadStore(instr); break;
// E: FP fixed point conversion.
// FP integer conversion.
// FP data processing 1 source.
// FP compare.
// FP immediate.
// FP data processing 2 source.
// FP conditional compare.
// FP conditional select.
// Advanced SIMD.
// F: FP data processing 3 source.
// Advanced SIMD.
case 0xE:
case 0xF: DecodeFP(instr); break;
}
}
}
void Decoder::AppendVisitor(DecoderVisitor* new_visitor) {
visitors_.push_back(new_visitor);
}
void Decoder::PrependVisitor(DecoderVisitor* new_visitor) {
visitors_.push_front(new_visitor);
}
void Decoder::InsertVisitorBefore(DecoderVisitor* new_visitor,
DecoderVisitor* registered_visitor) {
std::list<DecoderVisitor*>::iterator it;
for (it = visitors_.begin(); it != visitors_.end(); it++) {
if (*it == registered_visitor) {
visitors_.insert(it, new_visitor);
return;
}
}
// We reached the end of the list. The last element must be
// registered_visitor.
VIXL_ASSERT(*it == registered_visitor);
visitors_.insert(it, new_visitor);
}
void Decoder::InsertVisitorAfter(DecoderVisitor* new_visitor,
DecoderVisitor* registered_visitor) {
std::list<DecoderVisitor*>::iterator it;
for (it = visitors_.begin(); it != visitors_.end(); it++) {
if (*it == registered_visitor) {
it++;
visitors_.insert(it, new_visitor);
return;
}
}
// We reached the end of the list. The last element must be
// registered_visitor.
VIXL_ASSERT(*it == registered_visitor);
visitors_.push_back(new_visitor);
}
void Decoder::RemoveVisitor(DecoderVisitor* visitor) {
visitors_.remove(visitor);
}
void Decoder::DecodePCRelAddressing(const Instruction* instr) {
VIXL_ASSERT(instr->Bits(27, 24) == 0x0);
// We know bit 28 is set, as <b28:b27> = 0 is filtered out at the top level
// decode.
VIXL_ASSERT(instr->Bit(28) == 0x1);
VisitPCRelAddressing(instr);
}
void Decoder::DecodeBranchSystemException(const Instruction* instr) {
VIXL_ASSERT((instr->Bits(27, 24) == 0x4) ||
(instr->Bits(27, 24) == 0x5) ||
(instr->Bits(27, 24) == 0x6) ||
(instr->Bits(27, 24) == 0x7) );
switch (instr->Bits(31, 29)) {
case 0:
case 4: {
VisitUnconditionalBranch(instr);
break;
}
case 1:
case 5: {
if (instr->Bit(25) == 0) {
VisitCompareBranch(instr);
} else {
VisitTestBranch(instr);
}
break;
}
case 2: {
if (instr->Bit(25) == 0) {
if ((instr->Bit(24) == 0x1) ||
(instr->Mask(0x01000010) == 0x00000010)) {
VisitUnallocated(instr);
} else {
VisitConditionalBranch(instr);
}
} else {
VisitUnallocated(instr);
}
break;
}
case 6: {
if (instr->Bit(25) == 0) {
if (instr->Bit(24) == 0) {
if ((instr->Bits(4, 2) != 0) ||
(instr->Mask(0x00E0001D) == 0x00200001) ||
(instr->Mask(0x00E0001D) == 0x00400001) ||
(instr->Mask(0x00E0001E) == 0x00200002) ||
(instr->Mask(0x00E0001E) == 0x00400002) ||
(instr->Mask(0x00E0001C) == 0x00600000) ||
(instr->Mask(0x00E0001C) == 0x00800000) ||
(instr->Mask(0x00E0001F) == 0x00A00000) ||
(instr->Mask(0x00C0001C) == 0x00C00000)) {
VisitUnallocated(instr);
} else {
VisitException(instr);
}
} else {
if (instr->Bits(23, 22) == 0) {
const Instr masked_003FF0E0 = instr->Mask(0x003FF0E0);
if ((instr->Bits(21, 19) == 0x4) ||
(masked_003FF0E0 == 0x00033000) ||
(masked_003FF0E0 == 0x003FF020) ||
(masked_003FF0E0 == 0x003FF060) ||
(masked_003FF0E0 == 0x003FF0E0) ||
(instr->Mask(0x00388000) == 0x00008000) ||
(instr->Mask(0x0038E000) == 0x00000000) ||
(instr->Mask(0x0039E000) == 0x00002000) ||
(instr->Mask(0x003AE000) == 0x00002000) ||
(instr->Mask(0x003CE000) == 0x00042000) ||
(instr->Mask(0x003FFFC0) == 0x000320C0) ||
(instr->Mask(0x003FF100) == 0x00032100) ||
(instr->Mask(0x003FF200) == 0x00032200) ||
(instr->Mask(0x003FF400) == 0x00032400) ||
(instr->Mask(0x003FF800) == 0x00032800) ||
(instr->Mask(0x0038F000) == 0x00005000) ||
(instr->Mask(0x0038E000) == 0x00006000)) {
VisitUnallocated(instr);
} else {
VisitSystem(instr);
}
} else {
VisitUnallocated(instr);
}
}
} else {
if ((instr->Bit(24) == 0x1) ||
(instr->Bits(20, 16) != 0x1F) ||
(instr->Bits(15, 10) != 0) ||
(instr->Bits(4, 0) != 0) ||
(instr->Bits(24, 21) == 0x3) ||
(instr->Bits(24, 22) == 0x3)) {
VisitUnallocated(instr);
} else {
VisitUnconditionalBranchToRegister(instr);
}
}
break;
}
case 3:
case 7: {
VisitUnallocated(instr);
break;
}
}
}
void Decoder::DecodeLoadStore(const Instruction* instr) {
VIXL_ASSERT((instr->Bits(27, 24) == 0x8) ||
(instr->Bits(27, 24) == 0x9) ||
(instr->Bits(27, 24) == 0xC) ||
(instr->Bits(27, 24) == 0xD) );
if (instr->Bit(24) == 0) {
if (instr->Bit(28) == 0) {
if (instr->Bit(29) == 0) {
if (instr->Bit(26) == 0) {
VisitLoadStoreExclusive(instr);
} else {
DecodeAdvSIMDLoadStore(instr);
}
} else {
if ((instr->Bits(31, 30) == 0x3) ||
(instr->Mask(0xC4400000) == 0x40000000)) {
VisitUnallocated(instr);
} else {
if (instr->Bit(23) == 0) {
if (instr->Mask(0xC4400000) == 0xC0400000) {
VisitUnallocated(instr);
} else {
VisitLoadStorePairNonTemporal(instr);
}
} else {
VisitLoadStorePairPostIndex(instr);
}
}
}
} else {
if (instr->Bit(29) == 0) {
if (instr->Mask(0xC4000000) == 0xC4000000) {
VisitUnallocated(instr);
} else {
VisitLoadLiteral(instr);
}
} else {
if ((instr->Mask(0x84C00000) == 0x80C00000) ||
(instr->Mask(0x44800000) == 0x44800000) ||
(instr->Mask(0x84800000) == 0x84800000)) {
VisitUnallocated(instr);
} else {
if (instr->Bit(21) == 0) {
switch (instr->Bits(11, 10)) {
case 0: {
VisitLoadStoreUnscaledOffset(instr);
break;
}
case 1: {
if (instr->Mask(0xC4C00000) == 0xC0800000) {
VisitUnallocated(instr);
} else {
VisitLoadStorePostIndex(instr);
}
break;
}
case 2: {
// TODO: VisitLoadStoreRegisterOffsetUnpriv.
VisitUnimplemented(instr);
break;
}
case 3: {
if (instr->Mask(0xC4C00000) == 0xC0800000) {
VisitUnallocated(instr);
} else {
VisitLoadStorePreIndex(instr);
}
break;
}
}
} else {
if (instr->Bits(11, 10) == 0x2) {
if (instr->Bit(14) == 0) {
VisitUnallocated(instr);
} else {
VisitLoadStoreRegisterOffset(instr);
}
} else {
VisitUnallocated(instr);
}
}
}
}
}
} else {
if (instr->Bit(28) == 0) {
if (instr->Bit(29) == 0) {
VisitUnallocated(instr);
} else {
if ((instr->Bits(31, 30) == 0x3) ||
(instr->Mask(0xC4400000) == 0x40000000)) {
VisitUnallocated(instr);
} else {
if (instr->Bit(23) == 0) {
VisitLoadStorePairOffset(instr);
} else {
VisitLoadStorePairPreIndex(instr);
}
}
}
} else {
if (instr->Bit(29) == 0) {
VisitUnallocated(instr);
} else {
if ((instr->Mask(0x84C00000) == 0x80C00000) ||
(instr->Mask(0x44800000) == 0x44800000) ||
(instr->Mask(0x84800000) == 0x84800000)) {
VisitUnallocated(instr);
} else {
VisitLoadStoreUnsignedOffset(instr);
}
}
}
}
}
void Decoder::DecodeLogical(const Instruction* instr) {
VIXL_ASSERT(instr->Bits(27, 24) == 0x2);
if (instr->Mask(0x80400000) == 0x00400000) {
VisitUnallocated(instr);
} else {
if (instr->Bit(23) == 0) {
VisitLogicalImmediate(instr);
} else {
if (instr->Bits(30, 29) == 0x1) {
VisitUnallocated(instr);
} else {
VisitMoveWideImmediate(instr);
}
}
}
}
void Decoder::DecodeBitfieldExtract(const Instruction* instr) {
VIXL_ASSERT(instr->Bits(27, 24) == 0x3);
if ((instr->Mask(0x80400000) == 0x80000000) ||
(instr->Mask(0x80400000) == 0x00400000) ||
(instr->Mask(0x80008000) == 0x00008000)) {
VisitUnallocated(instr);
} else if (instr->Bit(23) == 0) {
if ((instr->Mask(0x80200000) == 0x00200000) ||
(instr->Mask(0x60000000) == 0x60000000)) {
VisitUnallocated(instr);
} else {
VisitBitfield(instr);
}
} else {
if ((instr->Mask(0x60200000) == 0x00200000) ||
(instr->Mask(0x60000000) != 0x00000000)) {
VisitUnallocated(instr);
} else {
VisitExtract(instr);
}
}
}
void Decoder::DecodeAddSubImmediate(const Instruction* instr) {
VIXL_ASSERT(instr->Bits(27, 24) == 0x1);
if (instr->Bit(23) == 1) {
VisitUnallocated(instr);
} else {
VisitAddSubImmediate(instr);
}
}
void Decoder::DecodeDataProcessing(const Instruction* instr) {
VIXL_ASSERT((instr->Bits(27, 24) == 0xA) ||
(instr->Bits(27, 24) == 0xB));
if (instr->Bit(24) == 0) {
if (instr->Bit(28) == 0) {
if (instr->Mask(0x80008000) == 0x00008000) {
VisitUnallocated(instr);
} else {
VisitLogicalShifted(instr);
}
} else {
switch (instr->Bits(23, 21)) {
case 0: {
if (instr->Mask(0x0000FC00) != 0) {
VisitUnallocated(instr);
} else {
VisitAddSubWithCarry(instr);
}
break;
}
case 2: {
if ((instr->Bit(29) == 0) ||
(instr->Mask(0x00000410) != 0)) {
VisitUnallocated(instr);
} else {
if (instr->Bit(11) == 0) {
VisitConditionalCompareRegister(instr);
} else {
VisitConditionalCompareImmediate(instr);
}
}
break;
}
case 4: {
if (instr->Mask(0x20000800) != 0x00000000) {
VisitUnallocated(instr);
} else {
VisitConditionalSelect(instr);
}
break;
}
case 6: {
if (instr->Bit(29) == 0x1) {
VisitUnallocated(instr);
} else {
if (instr->Bit(30) == 0) {
if ((instr->Bit(15) == 0x1) ||
(instr->Bits(15, 11) == 0) ||
(instr->Bits(15, 12) == 0x1) ||
(instr->Bits(15, 12) == 0x3) ||
(instr->Bits(15, 13) == 0x3) ||
(instr->Mask(0x8000EC00) == 0x00004C00) ||
(instr->Mask(0x8000E800) == 0x80004000) ||
(instr->Mask(0x8000E400) == 0x80004000)) {
VisitUnallocated(instr);
} else {
VisitDataProcessing2Source(instr);
}
} else {
if ((instr->Bit(13) == 1) ||
(instr->Bits(20, 16) != 0) ||
(instr->Bits(15, 14) != 0) ||
(instr->Mask(0xA01FFC00) == 0x00000C00) ||
(instr->Mask(0x201FF800) == 0x00001800)) {
VisitUnallocated(instr);
} else {
VisitDataProcessing1Source(instr);
}
}
break;
}
}
case 1:
case 3:
case 5:
case 7: VisitUnallocated(instr); break;
}
}
} else {
if (instr->Bit(28) == 0) {
if (instr->Bit(21) == 0) {
if ((instr->Bits(23, 22) == 0x3) ||
(instr->Mask(0x80008000) == 0x00008000)) {
VisitUnallocated(instr);
} else {
VisitAddSubShifted(instr);
}
} else {
if ((instr->Mask(0x00C00000) != 0x00000000) ||
(instr->Mask(0x00001400) == 0x00001400) ||
(instr->Mask(0x00001800) == 0x00001800)) {
VisitUnallocated(instr);
} else {
VisitAddSubExtended(instr);
}
}
} else {
if ((instr->Bit(30) == 0x1) ||
(instr->Bits(30, 29) == 0x1) ||
(instr->Mask(0xE0600000) == 0x00200000) ||
(instr->Mask(0xE0608000) == 0x00400000) ||
(instr->Mask(0x60608000) == 0x00408000) ||
(instr->Mask(0x60E00000) == 0x00E00000) ||
(instr->Mask(0x60E00000) == 0x00800000) ||
(instr->Mask(0x60E00000) == 0x00600000)) {
VisitUnallocated(instr);
} else {
VisitDataProcessing3Source(instr);
}
}
}
}
void Decoder::DecodeFP(const Instruction* instr) {
VIXL_ASSERT((instr->Bits(27, 24) == 0xE) ||
(instr->Bits(27, 24) == 0xF));
if (instr->Bit(28) == 0) {
DecodeAdvSIMDDataProcessing(instr);
} else {
if (instr->Bit(29) == 1) {
VisitUnallocated(instr);
} else {
if (instr->Bits(31, 30) == 0x3) {
VisitUnallocated(instr);
} else if (instr->Bits(31, 30) == 0x1) {
DecodeAdvSIMDDataProcessing(instr);
} else {
if (instr->Bit(24) == 0) {
if (instr->Bit(21) == 0) {
if ((instr->Bit(23) == 1) ||
(instr->Bit(18) == 1) ||
(instr->Mask(0x80008000) == 0x00000000) ||
(instr->Mask(0x000E0000) == 0x00000000) ||
(instr->Mask(0x000E0000) == 0x000A0000) ||
(instr->Mask(0x00160000) == 0x00000000) ||
(instr->Mask(0x00160000) == 0x00120000)) {
VisitUnallocated(instr);
} else {
VisitFPFixedPointConvert(instr);
}
} else {
if (instr->Bits(15, 10) == 32) {
VisitUnallocated(instr);
} else if (instr->Bits(15, 10) == 0) {
if ((instr->Bits(23, 22) == 0x3) ||
(instr->Mask(0x000E0000) == 0x000A0000) ||
(instr->Mask(0x000E0000) == 0x000C0000) ||
(instr->Mask(0x00160000) == 0x00120000) ||
(instr->Mask(0x00160000) == 0x00140000) ||
(instr->Mask(0x20C40000) == 0x00800000) ||
(instr->Mask(0x20C60000) == 0x00840000) ||
(instr->Mask(0xA0C60000) == 0x80060000) ||
(instr->Mask(0xA0C60000) == 0x00860000) ||
(instr->Mask(0xA0C60000) == 0x00460000) ||
(instr->Mask(0xA0CE0000) == 0x80860000) ||
(instr->Mask(0xA0CE0000) == 0x804E0000) ||
(instr->Mask(0xA0CE0000) == 0x000E0000) ||
(instr->Mask(0xA0D60000) == 0x00160000) ||
(instr->Mask(0xA0D60000) == 0x80560000) ||
(instr->Mask(0xA0D60000) == 0x80960000)) {
VisitUnallocated(instr);
} else {
VisitFPIntegerConvert(instr);
}
} else if (instr->Bits(14, 10) == 16) {
const Instr masked_A0DF8000 = instr->Mask(0xA0DF8000);
if ((instr->Mask(0x80180000) != 0) ||
(masked_A0DF8000 == 0x00020000) ||
(masked_A0DF8000 == 0x00030000) ||
(masked_A0DF8000 == 0x00068000) ||
(masked_A0DF8000 == 0x00428000) ||
(masked_A0DF8000 == 0x00430000) ||
(masked_A0DF8000 == 0x00468000) ||
(instr->Mask(0xA0D80000) == 0x00800000) ||
(instr->Mask(0xA0DE0000) == 0x00C00000) ||
(instr->Mask(0xA0DF0000) == 0x00C30000) ||
(instr->Mask(0xA0DC0000) == 0x00C40000)) {
VisitUnallocated(instr);
} else {
VisitFPDataProcessing1Source(instr);
}
} else if (instr->Bits(13, 10) == 8) {
if ((instr->Bits(15, 14) != 0) ||
(instr->Bits(2, 0) != 0) ||
(instr->Mask(0x80800000) != 0x00000000)) {
VisitUnallocated(instr);
} else {
VisitFPCompare(instr);
}
} else if (instr->Bits(12, 10) == 4) {
if ((instr->Bits(9, 5) != 0) ||
(instr->Mask(0x80800000) != 0x00000000)) {
VisitUnallocated(instr);
} else {
VisitFPImmediate(instr);
}
} else {
if (instr->Mask(0x80800000) != 0x00000000) {
VisitUnallocated(instr);
} else {
switch (instr->Bits(11, 10)) {
case 1: {
VisitFPConditionalCompare(instr);
break;
}
case 2: {
if ((instr->Bits(15, 14) == 0x3) ||
(instr->Mask(0x00009000) == 0x00009000) ||
(instr->Mask(0x0000A000) == 0x0000A000)) {
VisitUnallocated(instr);
} else {
VisitFPDataProcessing2Source(instr);
}
break;
}
case 3: {
VisitFPConditionalSelect(instr);
break;
}
default: VIXL_UNREACHABLE();
}
}
}
}
} else {
// Bit 30 == 1 has been handled earlier.
VIXL_ASSERT(instr->Bit(30) == 0);
if (instr->Mask(0xA0800000) != 0) {
VisitUnallocated(instr);
} else {
VisitFPDataProcessing3Source(instr);
}
}
}
}
}
}
void Decoder::DecodeAdvSIMDLoadStore(const Instruction* instr) {
// TODO: Implement Advanced SIMD load/store instruction decode.
VIXL_ASSERT(instr->Bits(29, 25) == 0x6);
VisitUnimplemented(instr);
}
void Decoder::DecodeAdvSIMDDataProcessing(const Instruction* instr) {
// TODO: Implement Advanced SIMD data processing instruction decode.
VIXL_ASSERT(instr->Bits(27, 25) == 0x7);
VisitUnimplemented(instr);
}
#define DEFINE_VISITOR_CALLERS(A) \
void Decoder::Visit##A(const Instruction *instr) { \
VIXL_ASSERT(instr->Mask(A##FMask) == A##Fixed); \
std::list<DecoderVisitor*>::iterator it; \
for (it = visitors_.begin(); it != visitors_.end(); it++) { \
(*it)->Visit##A(instr); \
} \
}
VISITOR_LIST(DEFINE_VISITOR_CALLERS)
#undef DEFINE_VISITOR_CALLERS
} // namespace vixl