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Diffstat (limited to 'js/src/jit/arm64/vixl/Instructions-vixl.h')
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diff --git a/js/src/jit/arm64/vixl/Instructions-vixl.h b/js/src/jit/arm64/vixl/Instructions-vixl.h new file mode 100644 index 0000000000..4bcddf642a --- /dev/null +++ b/js/src/jit/arm64/vixl/Instructions-vixl.h @@ -0,0 +1,817 @@ +// Copyright 2015, 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. + +#ifndef VIXL_A64_INSTRUCTIONS_A64_H_ +#define VIXL_A64_INSTRUCTIONS_A64_H_ + +#include "jit/arm64/vixl/Constants-vixl.h" +#include "jit/arm64/vixl/Globals-vixl.h" +#include "jit/arm64/vixl/Utils-vixl.h" + +namespace vixl { +// ISA constants. -------------------------------------------------------------- + +typedef uint32_t Instr; +const unsigned kInstructionSize = 4; +const unsigned kInstructionSizeLog2 = 2; +const unsigned kLiteralEntrySize = 4; +const unsigned kLiteralEntrySizeLog2 = 2; +const unsigned kMaxLoadLiteralRange = 1 * MBytes; + +// This is the nominal page size (as used by the adrp instruction); the actual +// size of the memory pages allocated by the kernel is likely to differ. +const unsigned kPageSize = 4 * KBytes; +const unsigned kPageSizeLog2 = 12; + +const unsigned kBRegSize = 8; +const unsigned kBRegSizeLog2 = 3; +const unsigned kBRegSizeInBytes = kBRegSize / 8; +const unsigned kBRegSizeInBytesLog2 = kBRegSizeLog2 - 3; +const unsigned kHRegSize = 16; +const unsigned kHRegSizeLog2 = 4; +const unsigned kHRegSizeInBytes = kHRegSize / 8; +const unsigned kHRegSizeInBytesLog2 = kHRegSizeLog2 - 3; +const unsigned kWRegSize = 32; +const unsigned kWRegSizeLog2 = 5; +const unsigned kWRegSizeInBytes = kWRegSize / 8; +const unsigned kWRegSizeInBytesLog2 = kWRegSizeLog2 - 3; +const unsigned kXRegSize = 64; +const unsigned kXRegSizeLog2 = 6; +const unsigned kXRegSizeInBytes = kXRegSize / 8; +const unsigned kXRegSizeInBytesLog2 = kXRegSizeLog2 - 3; +const unsigned kSRegSize = 32; +const unsigned kSRegSizeLog2 = 5; +const unsigned kSRegSizeInBytes = kSRegSize / 8; +const unsigned kSRegSizeInBytesLog2 = kSRegSizeLog2 - 3; +const unsigned kDRegSize = 64; +const unsigned kDRegSizeLog2 = 6; +const unsigned kDRegSizeInBytes = kDRegSize / 8; +const unsigned kDRegSizeInBytesLog2 = kDRegSizeLog2 - 3; +const unsigned kQRegSize = 128; +const unsigned kQRegSizeLog2 = 7; +const unsigned kQRegSizeInBytes = kQRegSize / 8; +const unsigned kQRegSizeInBytesLog2 = kQRegSizeLog2 - 3; +const uint64_t kWRegMask = UINT64_C(0xffffffff); +const uint64_t kXRegMask = UINT64_C(0xffffffffffffffff); +const uint64_t kSRegMask = UINT64_C(0xffffffff); +const uint64_t kDRegMask = UINT64_C(0xffffffffffffffff); +const uint64_t kSSignMask = UINT64_C(0x80000000); +const uint64_t kDSignMask = UINT64_C(0x8000000000000000); +const uint64_t kWSignMask = UINT64_C(0x80000000); +const uint64_t kXSignMask = UINT64_C(0x8000000000000000); +const uint64_t kByteMask = UINT64_C(0xff); +const uint64_t kHalfWordMask = UINT64_C(0xffff); +const uint64_t kWordMask = UINT64_C(0xffffffff); +const uint64_t kXMaxUInt = UINT64_C(0xffffffffffffffff); +const uint64_t kXMaxExactUInt = UINT64_C(0xfffffffffffff800); +const uint64_t kWMaxUInt = UINT64_C(0xffffffff); +const int64_t kXMaxInt = INT64_C(0x7fffffffffffffff); +const int64_t kXMaxExactInt = UINT64_C(0x7ffffffffffffc00); +const int64_t kXMinInt = INT64_C(0x8000000000000000); +const int32_t kWMaxInt = INT32_C(0x7fffffff); +const int32_t kWMinInt = INT32_C(0x80000000); +const unsigned kLinkRegCode = 30; +const unsigned kZeroRegCode = 31; +const unsigned kSPRegInternalCode = 63; +const unsigned kRegCodeMask = 0x1f; + +const unsigned kAddressTagOffset = 56; +const unsigned kAddressTagWidth = 8; +const uint64_t kAddressTagMask = + ((UINT64_C(1) << kAddressTagWidth) - 1) << kAddressTagOffset; +VIXL_STATIC_ASSERT(kAddressTagMask == UINT64_C(0xff00000000000000)); + +static inline unsigned CalcLSDataSize(LoadStoreOp op) { + VIXL_ASSERT((LSSize_offset + LSSize_width) == (kInstructionSize * 8)); + unsigned size = static_cast<Instr>(op) >> LSSize_offset; + if ((op & LSVector_mask) != 0) { + // Vector register memory operations encode the access size in the "size" + // and "opc" fields. + if ((size == 0) && ((op & LSOpc_mask) >> LSOpc_offset) >= 2) { + size = kQRegSizeInBytesLog2; + } + } + return size; +} + +unsigned CalcLSPairDataSize(LoadStorePairOp op); + +enum ImmBranchType { + UnknownBranchType = 0, + CondBranchType = 1, + UncondBranchType = 2, + CompareBranchType = 3, + TestBranchType = 4 +}; + +// The classes of immediate branch ranges, in order of increasing range. +// Note that CondBranchType and CompareBranchType have the same range. +enum ImmBranchRangeType { + TestBranchRangeType, // tbz/tbnz: imm14 = +/- 32KB. + CondBranchRangeType, // b.cond/cbz/cbnz: imm19 = +/- 1MB. + UncondBranchRangeType, // b/bl: imm26 = +/- 128MB. + UnknownBranchRangeType, + + // Number of 'short-range' branch range types. + // We don't consider unconditional branches 'short-range'. + NumShortBranchRangeTypes = UncondBranchRangeType +}; + +enum AddrMode { + Offset, + PreIndex, + PostIndex +}; + +enum Reg31Mode { + Reg31IsStackPointer, + Reg31IsZeroRegister +}; + +// Instructions. --------------------------------------------------------------- + +class Instruction { + public: + Instr InstructionBits() const { + return *(reinterpret_cast<const Instr*>(this)); + } + + void SetInstructionBits(Instr new_instr) { + *(reinterpret_cast<Instr*>(this)) = new_instr; + } + + int Bit(int pos) const { + return (InstructionBits() >> pos) & 1; + } + + uint32_t Bits(int msb, int lsb) const { + return ExtractUnsignedBitfield32(msb, lsb, InstructionBits()); + } + + int32_t SignedBits(int msb, int lsb) const { + int32_t bits = *(reinterpret_cast<const int32_t*>(this)); + return ExtractSignedBitfield32(msb, lsb, bits); + } + + Instr Mask(uint32_t mask) const { + return InstructionBits() & mask; + } + + #define DEFINE_GETTER(Name, HighBit, LowBit, Func) \ + int32_t Name() const { return Func(HighBit, LowBit); } + INSTRUCTION_FIELDS_LIST(DEFINE_GETTER) + #undef DEFINE_GETTER + + #define DEFINE_SETTER(Name, HighBit, LowBit, Func) \ + inline void Set##Name(unsigned n) { SetBits32(HighBit, LowBit, n); } + INSTRUCTION_FIELDS_LIST(DEFINE_SETTER) + #undef DEFINE_SETTER + + // ImmPCRel is a compound field (not present in INSTRUCTION_FIELDS_LIST), + // formed from ImmPCRelLo and ImmPCRelHi. + int ImmPCRel() const { + int offset = + static_cast<int>((ImmPCRelHi() << ImmPCRelLo_width) | ImmPCRelLo()); + int width = ImmPCRelLo_width + ImmPCRelHi_width; + return ExtractSignedBitfield32(width - 1, 0, offset); + } + + uint64_t ImmLogical() const; + unsigned ImmNEONabcdefgh() const; + float ImmFP32() const; + double ImmFP64() const; + float ImmNEONFP32() const; + double ImmNEONFP64() const; + + unsigned SizeLS() const { + return CalcLSDataSize(static_cast<LoadStoreOp>(Mask(LoadStoreMask))); + } + + unsigned SizeLSPair() const { + return CalcLSPairDataSize( + static_cast<LoadStorePairOp>(Mask(LoadStorePairMask))); + } + + int NEONLSIndex(int access_size_shift) const { + int64_t q = NEONQ(); + int64_t s = NEONS(); + int64_t size = NEONLSSize(); + int64_t index = (q << 3) | (s << 2) | size; + return static_cast<int>(index >> access_size_shift); + } + + // Helpers. + bool IsCondBranchImm() const { + return Mask(ConditionalBranchFMask) == ConditionalBranchFixed; + } + + bool IsUncondBranchImm() const { + return Mask(UnconditionalBranchFMask) == UnconditionalBranchFixed; + } + + bool IsCompareBranch() const { + return Mask(CompareBranchFMask) == CompareBranchFixed; + } + + bool IsTestBranch() const { + return Mask(TestBranchFMask) == TestBranchFixed; + } + + bool IsImmBranch() const { + return BranchType() != UnknownBranchType; + } + + bool IsPCRelAddressing() const { + return Mask(PCRelAddressingFMask) == PCRelAddressingFixed; + } + + bool IsLogicalImmediate() const { + return Mask(LogicalImmediateFMask) == LogicalImmediateFixed; + } + + bool IsAddSubImmediate() const { + return Mask(AddSubImmediateFMask) == AddSubImmediateFixed; + } + + bool IsAddSubExtended() const { + return Mask(AddSubExtendedFMask) == AddSubExtendedFixed; + } + + bool IsLoadOrStore() const { + return Mask(LoadStoreAnyFMask) == LoadStoreAnyFixed; + } + + bool IsLoad() const; + bool IsStore() const; + + bool IsLoadLiteral() const { + // This includes PRFM_lit. + return Mask(LoadLiteralFMask) == LoadLiteralFixed; + } + + bool IsMovn() const { + return (Mask(MoveWideImmediateMask) == MOVN_x) || + (Mask(MoveWideImmediateMask) == MOVN_w); + } + + // Mozilla modifications. + bool IsUncondB() const; + bool IsCondB() const; + bool IsBL() const; + bool IsBR() const; + bool IsBLR() const; + bool IsTBZ() const; + bool IsTBNZ() const; + bool IsCBZ() const; + bool IsCBNZ() const; + bool IsLDR() const; + bool IsNOP() const; + bool IsCSDB() const; + bool IsADR() const; + bool IsADRP() const; + bool IsMovz() const; + bool IsMovk() const; + bool IsBranchLinkImm() const; + bool IsTargetReachable(const Instruction* target) const; + ptrdiff_t ImmPCRawOffset() const; + void SetImmPCRawOffset(ptrdiff_t offset); + void SetBits32(int msb, int lsb, unsigned value); + + // Is this a stack pointer synchronization instruction as inserted by + // MacroAssembler::syncStackPtr()? + bool IsStackPtrSync() const; + + static int ImmBranchRangeBitwidth(ImmBranchType branch_type); + static int32_t ImmBranchForwardRange(ImmBranchType branch_type); + + // Check if offset can be encoded as a RAW offset in a branch_type + // instruction. The offset must be encodeable directly as the immediate field + // in the instruction, it is not scaled by kInstructionSize first. + static bool IsValidImmPCOffset(ImmBranchType branch_type, int64_t offset); + + // Get the range type corresponding to a branch type. + static ImmBranchRangeType ImmBranchTypeToRange(ImmBranchType); + + // Get the maximum realizable forward PC offset (in bytes) for an immediate + // branch of the given range type. + // This is the largest positive multiple of kInstructionSize, offset, such + // that: + // + // IsValidImmPCOffset(xxx, offset / kInstructionSize) + // + // returns true for the same branch type. + static int32_t ImmBranchMaxForwardOffset(ImmBranchRangeType range_type); + + // Get the minimuum realizable backward PC offset (in bytes) for an immediate + // branch of the given range type. + // This is the smallest (i.e., largest in magnitude) negative multiple of + // kInstructionSize, offset, such that: + // + // IsValidImmPCOffset(xxx, offset / kInstructionSize) + // + // returns true for the same branch type. + static int32_t ImmBranchMinBackwardOffset(ImmBranchRangeType range_type); + + // Indicate whether Rd can be the stack pointer or the zero register. This + // does not check that the instruction actually has an Rd field. + Reg31Mode RdMode() const { + // The following instructions use sp or wsp as Rd: + // Add/sub (immediate) when not setting the flags. + // Add/sub (extended) when not setting the flags. + // Logical (immediate) when not setting the flags. + // Otherwise, r31 is the zero register. + if (IsAddSubImmediate() || IsAddSubExtended()) { + if (Mask(AddSubSetFlagsBit)) { + return Reg31IsZeroRegister; + } else { + return Reg31IsStackPointer; + } + } + if (IsLogicalImmediate()) { + // Of the logical (immediate) instructions, only ANDS (and its aliases) + // can set the flags. The others can all write into sp. + // Note that some logical operations are not available to + // immediate-operand instructions, so we have to combine two masks here. + if (Mask(LogicalImmediateMask & LogicalOpMask) == ANDS) { + return Reg31IsZeroRegister; + } else { + return Reg31IsStackPointer; + } + } + return Reg31IsZeroRegister; + } + + // Indicate whether Rn can be the stack pointer or the zero register. This + // does not check that the instruction actually has an Rn field. + Reg31Mode RnMode() const { + // The following instructions use sp or wsp as Rn: + // All loads and stores. + // Add/sub (immediate). + // Add/sub (extended). + // Otherwise, r31 is the zero register. + if (IsLoadOrStore() || IsAddSubImmediate() || IsAddSubExtended()) { + return Reg31IsStackPointer; + } + return Reg31IsZeroRegister; + } + + ImmBranchType BranchType() const { + if (IsCondBranchImm()) { + return CondBranchType; + } else if (IsUncondBranchImm()) { + return UncondBranchType; + } else if (IsCompareBranch()) { + return CompareBranchType; + } else if (IsTestBranch()) { + return TestBranchType; + } else { + return UnknownBranchType; + } + } + + // Find the target of this instruction. 'this' may be a branch or a + // PC-relative addressing instruction. + const Instruction* ImmPCOffsetTarget() const; + + // Patch a PC-relative offset to refer to 'target'. 'this' may be a branch or + // a PC-relative addressing instruction. + void SetImmPCOffsetTarget(const Instruction* target); + // Patch a literal load instruction to load from 'source'. + void SetImmLLiteral(const Instruction* source); + + // The range of a load literal instruction, expressed as 'instr +- range'. + // The range is actually the 'positive' range; the branch instruction can + // target [instr - range - kInstructionSize, instr + range]. + static const int kLoadLiteralImmBitwidth = 19; + static const int kLoadLiteralRange = + (1 << kLoadLiteralImmBitwidth) / 2 - kInstructionSize; + + // Calculate the address of a literal referred to by a load-literal + // instruction, and return it as the specified type. + // + // The literal itself is safely mutable only if the backing buffer is safely + // mutable. + template <typename T> + T LiteralAddress() const { + uint64_t base_raw = reinterpret_cast<uint64_t>(this); + int64_t offset = ImmLLiteral() << kLiteralEntrySizeLog2; + uint64_t address_raw = base_raw + offset; + + // Cast the address using a C-style cast. A reinterpret_cast would be + // appropriate, but it can't cast one integral type to another. + T address = (T)(address_raw); + + // Assert that the address can be represented by the specified type. + VIXL_ASSERT((uint64_t)(address) == address_raw); + + return address; + } + + uint32_t Literal32() const { + uint32_t literal; + memcpy(&literal, LiteralAddress<const void*>(), sizeof(literal)); + return literal; + } + + uint64_t Literal64() const { + uint64_t literal; + memcpy(&literal, LiteralAddress<const void*>(), sizeof(literal)); + return literal; + } + + void SetLiteral64(uint64_t literal) const { + memcpy(LiteralAddress<void*>(), &literal, sizeof(literal)); + } + + float LiteralFP32() const { + return RawbitsToFloat(Literal32()); + } + + double LiteralFP64() const { + return RawbitsToDouble(Literal64()); + } + + const Instruction* NextInstruction() const { + return this + kInstructionSize; + } + + // Skip any constant pools with artificial guards at this point. + // Return either |this| or the first instruction after the pool. + const Instruction* skipPool() const; + + const Instruction* InstructionAtOffset(int64_t offset) const { + VIXL_ASSERT(IsWordAligned(this + offset)); + return this + offset; + } + + template<typename T> static Instruction* Cast(T src) { + return reinterpret_cast<Instruction*>(src); + } + + template<typename T> static const Instruction* CastConst(T src) { + return reinterpret_cast<const Instruction*>(src); + } + + private: + int ImmBranch() const; + + static float Imm8ToFP32(uint32_t imm8); + static double Imm8ToFP64(uint32_t imm8); + + void SetPCRelImmTarget(const Instruction* target); + void SetBranchImmTarget(const Instruction* target); +}; + + +// Functions for handling NEON vector format information. +enum VectorFormat { + kFormatUndefined = 0xffffffff, + kFormat8B = NEON_8B, + kFormat16B = NEON_16B, + kFormat4H = NEON_4H, + kFormat8H = NEON_8H, + kFormat2S = NEON_2S, + kFormat4S = NEON_4S, + kFormat1D = NEON_1D, + kFormat2D = NEON_2D, + + // Scalar formats. We add the scalar bit to distinguish between scalar and + // vector enumerations; the bit is always set in the encoding of scalar ops + // and always clear for vector ops. Although kFormatD and kFormat1D appear + // to be the same, their meaning is subtly different. The first is a scalar + // operation, the second a vector operation that only affects one lane. + kFormatB = NEON_B | NEONScalar, + kFormatH = NEON_H | NEONScalar, + kFormatS = NEON_S | NEONScalar, + kFormatD = NEON_D | NEONScalar +}; + +VectorFormat VectorFormatHalfWidth(const VectorFormat vform); +VectorFormat VectorFormatDoubleWidth(const VectorFormat vform); +VectorFormat VectorFormatDoubleLanes(const VectorFormat vform); +VectorFormat VectorFormatHalfLanes(const VectorFormat vform); +VectorFormat ScalarFormatFromLaneSize(int lanesize); +VectorFormat VectorFormatHalfWidthDoubleLanes(const VectorFormat vform); +VectorFormat VectorFormatFillQ(const VectorFormat vform); +unsigned RegisterSizeInBitsFromFormat(VectorFormat vform); +unsigned RegisterSizeInBytesFromFormat(VectorFormat vform); +// TODO: Make the return types of these functions consistent. +unsigned LaneSizeInBitsFromFormat(VectorFormat vform); +int LaneSizeInBytesFromFormat(VectorFormat vform); +int LaneSizeInBytesLog2FromFormat(VectorFormat vform); +int LaneCountFromFormat(VectorFormat vform); +int MaxLaneCountFromFormat(VectorFormat vform); +bool IsVectorFormat(VectorFormat vform); +int64_t MaxIntFromFormat(VectorFormat vform); +int64_t MinIntFromFormat(VectorFormat vform); +uint64_t MaxUintFromFormat(VectorFormat vform); + + +enum NEONFormat { + NF_UNDEF = 0, + NF_8B = 1, + NF_16B = 2, + NF_4H = 3, + NF_8H = 4, + NF_2S = 5, + NF_4S = 6, + NF_1D = 7, + NF_2D = 8, + NF_B = 9, + NF_H = 10, + NF_S = 11, + NF_D = 12 +}; + +static const unsigned kNEONFormatMaxBits = 6; + +struct NEONFormatMap { + // The bit positions in the instruction to consider. + uint8_t bits[kNEONFormatMaxBits]; + + // Mapping from concatenated bits to format. + NEONFormat map[1 << kNEONFormatMaxBits]; +}; + +class NEONFormatDecoder { + public: + enum SubstitutionMode { + kPlaceholder, + kFormat + }; + + // Construct a format decoder with increasingly specific format maps for each + // subsitution. If no format map is specified, the default is the integer + // format map. + explicit NEONFormatDecoder(const Instruction* instr) { + instrbits_ = instr->InstructionBits(); + SetFormatMaps(IntegerFormatMap()); + } + NEONFormatDecoder(const Instruction* instr, + const NEONFormatMap* format) { + instrbits_ = instr->InstructionBits(); + SetFormatMaps(format); + } + NEONFormatDecoder(const Instruction* instr, + const NEONFormatMap* format0, + const NEONFormatMap* format1) { + instrbits_ = instr->InstructionBits(); + SetFormatMaps(format0, format1); + } + NEONFormatDecoder(const Instruction* instr, + const NEONFormatMap* format0, + const NEONFormatMap* format1, + const NEONFormatMap* format2) { + instrbits_ = instr->InstructionBits(); + SetFormatMaps(format0, format1, format2); + } + + // Set the format mapping for all or individual substitutions. + void SetFormatMaps(const NEONFormatMap* format0, + const NEONFormatMap* format1 = NULL, + const NEONFormatMap* format2 = NULL) { + VIXL_ASSERT(format0 != NULL); + formats_[0] = format0; + formats_[1] = (format1 == NULL) ? formats_[0] : format1; + formats_[2] = (format2 == NULL) ? formats_[1] : format2; + } + void SetFormatMap(unsigned index, const NEONFormatMap* format) { + VIXL_ASSERT(index <= (sizeof(formats_) / sizeof(formats_[0]))); + VIXL_ASSERT(format != NULL); + formats_[index] = format; + } + + // Substitute %s in the input string with the placeholder string for each + // register, ie. "'B", "'H", etc. + const char* SubstitutePlaceholders(const char* string) { + return Substitute(string, kPlaceholder, kPlaceholder, kPlaceholder); + } + + // Substitute %s in the input string with a new string based on the + // substitution mode. + const char* Substitute(const char* string, + SubstitutionMode mode0 = kFormat, + SubstitutionMode mode1 = kFormat, + SubstitutionMode mode2 = kFormat) { + snprintf(form_buffer_, sizeof(form_buffer_), string, + GetSubstitute(0, mode0), + GetSubstitute(1, mode1), + GetSubstitute(2, mode2)); + return form_buffer_; + } + + // Append a "2" to a mnemonic string based of the state of the Q bit. + const char* Mnemonic(const char* mnemonic) { + if ((instrbits_ & NEON_Q) != 0) { + snprintf(mne_buffer_, sizeof(mne_buffer_), "%s2", mnemonic); + return mne_buffer_; + } + return mnemonic; + } + + VectorFormat GetVectorFormat(int format_index = 0) { + return GetVectorFormat(formats_[format_index]); + } + + VectorFormat GetVectorFormat(const NEONFormatMap* format_map) { + static const VectorFormat vform[] = { + kFormatUndefined, + kFormat8B, kFormat16B, kFormat4H, kFormat8H, + kFormat2S, kFormat4S, kFormat1D, kFormat2D, + kFormatB, kFormatH, kFormatS, kFormatD + }; + VIXL_ASSERT(GetNEONFormat(format_map) < (sizeof(vform) / sizeof(vform[0]))); + return vform[GetNEONFormat(format_map)]; + } + + // Built in mappings for common cases. + + // The integer format map uses three bits (Q, size<1:0>) to encode the + // "standard" set of NEON integer vector formats. + static const NEONFormatMap* IntegerFormatMap() { + static const NEONFormatMap map = { + {23, 22, 30}, + {NF_8B, NF_16B, NF_4H, NF_8H, NF_2S, NF_4S, NF_UNDEF, NF_2D} + }; + return ↦ + } + + // The long integer format map uses two bits (size<1:0>) to encode the + // long set of NEON integer vector formats. These are used in narrow, wide + // and long operations. + static const NEONFormatMap* LongIntegerFormatMap() { + static const NEONFormatMap map = { + {23, 22}, {NF_8H, NF_4S, NF_2D} + }; + return ↦ + } + + // The FP format map uses two bits (Q, size<0>) to encode the NEON FP vector + // formats: NF_2S, NF_4S, NF_2D. + static const NEONFormatMap* FPFormatMap() { + // The FP format map assumes two bits (Q, size<0>) are used to encode the + // NEON FP vector formats: NF_2S, NF_4S, NF_2D. + static const NEONFormatMap map = { + {22, 30}, {NF_2S, NF_4S, NF_UNDEF, NF_2D} + }; + return ↦ + } + + // The load/store format map uses three bits (Q, 11, 10) to encode the + // set of NEON vector formats. + static const NEONFormatMap* LoadStoreFormatMap() { + static const NEONFormatMap map = { + {11, 10, 30}, + {NF_8B, NF_16B, NF_4H, NF_8H, NF_2S, NF_4S, NF_1D, NF_2D} + }; + return ↦ + } + + // The logical format map uses one bit (Q) to encode the NEON vector format: + // NF_8B, NF_16B. + static const NEONFormatMap* LogicalFormatMap() { + static const NEONFormatMap map = { + {30}, {NF_8B, NF_16B} + }; + return ↦ + } + + // The triangular format map uses between two and five bits to encode the NEON + // vector format: + // xxx10->8B, xxx11->16B, xx100->4H, xx101->8H + // x1000->2S, x1001->4S, 10001->2D, all others undefined. + static const NEONFormatMap* TriangularFormatMap() { + static const NEONFormatMap map = { + {19, 18, 17, 16, 30}, + {NF_UNDEF, NF_UNDEF, NF_8B, NF_16B, NF_4H, NF_8H, NF_8B, NF_16B, NF_2S, + NF_4S, NF_8B, NF_16B, NF_4H, NF_8H, NF_8B, NF_16B, NF_UNDEF, NF_2D, + NF_8B, NF_16B, NF_4H, NF_8H, NF_8B, NF_16B, NF_2S, NF_4S, NF_8B, NF_16B, + NF_4H, NF_8H, NF_8B, NF_16B} + }; + return ↦ + } + + // The scalar format map uses two bits (size<1:0>) to encode the NEON scalar + // formats: NF_B, NF_H, NF_S, NF_D. + static const NEONFormatMap* ScalarFormatMap() { + static const NEONFormatMap map = { + {23, 22}, {NF_B, NF_H, NF_S, NF_D} + }; + return ↦ + } + + // The long scalar format map uses two bits (size<1:0>) to encode the longer + // NEON scalar formats: NF_H, NF_S, NF_D. + static const NEONFormatMap* LongScalarFormatMap() { + static const NEONFormatMap map = { + {23, 22}, {NF_H, NF_S, NF_D} + }; + return ↦ + } + + // The FP scalar format map assumes one bit (size<0>) is used to encode the + // NEON FP scalar formats: NF_S, NF_D. + static const NEONFormatMap* FPScalarFormatMap() { + static const NEONFormatMap map = { + {22}, {NF_S, NF_D} + }; + return ↦ + } + + // The triangular scalar format map uses between one and four bits to encode + // the NEON FP scalar formats: + // xxx1->B, xx10->H, x100->S, 1000->D, all others undefined. + static const NEONFormatMap* TriangularScalarFormatMap() { + static const NEONFormatMap map = { + {19, 18, 17, 16}, + {NF_UNDEF, NF_B, NF_H, NF_B, NF_S, NF_B, NF_H, NF_B, + NF_D, NF_B, NF_H, NF_B, NF_S, NF_B, NF_H, NF_B} + }; + return ↦ + } + + private: + // Get a pointer to a string that represents the format or placeholder for + // the specified substitution index, based on the format map and instruction. + const char* GetSubstitute(int index, SubstitutionMode mode) { + if (mode == kFormat) { + return NEONFormatAsString(GetNEONFormat(formats_[index])); + } + VIXL_ASSERT(mode == kPlaceholder); + return NEONFormatAsPlaceholder(GetNEONFormat(formats_[index])); + } + + // Get the NEONFormat enumerated value for bits obtained from the + // instruction based on the specified format mapping. + NEONFormat GetNEONFormat(const NEONFormatMap* format_map) { + return format_map->map[PickBits(format_map->bits)]; + } + + // Convert a NEONFormat into a string. + static const char* NEONFormatAsString(NEONFormat format) { + static const char* formats[] = { + "undefined", + "8b", "16b", "4h", "8h", "2s", "4s", "1d", "2d", + "b", "h", "s", "d" + }; + VIXL_ASSERT(format < (sizeof(formats) / sizeof(formats[0]))); + return formats[format]; + } + + // Convert a NEONFormat into a register placeholder string. + static const char* NEONFormatAsPlaceholder(NEONFormat format) { + VIXL_ASSERT((format == NF_B) || (format == NF_H) || + (format == NF_S) || (format == NF_D) || + (format == NF_UNDEF)); + static const char* formats[] = { + "undefined", + "undefined", "undefined", "undefined", "undefined", + "undefined", "undefined", "undefined", "undefined", + "'B", "'H", "'S", "'D" + }; + return formats[format]; + } + + // Select bits from instrbits_ defined by the bits array, concatenate them, + // and return the value. + uint8_t PickBits(const uint8_t bits[]) { + uint8_t result = 0; + for (unsigned b = 0; b < kNEONFormatMaxBits; b++) { + if (bits[b] == 0) break; + result <<= 1; + result |= ((instrbits_ & (1 << bits[b])) == 0) ? 0 : 1; + } + return result; + } + + Instr instrbits_; + const NEONFormatMap* formats_[3]; + char form_buffer_[64]; + char mne_buffer_[16]; +}; +} // namespace vixl + +#endif // VIXL_A64_INSTRUCTIONS_A64_H_ |