| // Copyright 2017 the V8 project authors. All rights reserved. |
| // Use of this source code is governed by a BSD-style license that can be |
| // found in the LICENSE file. |
| |
| #ifndef V8_WASM_BASELINE_LIFTOFF_REGISTER_H_ |
| #define V8_WASM_BASELINE_LIFTOFF_REGISTER_H_ |
| |
| #include <iosfwd> |
| #include <memory> |
| |
| // Clients of this interface shouldn't depend on lots of compiler internals. |
| // Do not include anything from src/compiler here! |
| #include "src/base/bits.h" |
| #include "src/wasm/baseline/liftoff-assembler-defs.h" |
| #include "src/wasm/wasm-opcodes.h" |
| |
| namespace v8 { |
| namespace internal { |
| namespace wasm { |
| |
| enum RegClass { kNoReg, kGpReg, kFpReg }; |
| |
| // TODO(clemensh): Use a switch once we require C++14 support. |
| static inline constexpr RegClass reg_class_for(ValueType type) { |
| return type == kWasmI32 || type == kWasmI64 // int types |
| ? kGpReg |
| : type == kWasmF32 || type == kWasmF64 // float types |
| ? kFpReg |
| : kNoReg; // other (unsupported) types |
| } |
| |
| // RegForClass<rc>: Register for rc==kGpReg, DoubleRegister for rc==kFpReg, void |
| // for all other values of rc. |
| template <RegClass rc> |
| using RegForClass = typename std::conditional< |
| rc == kGpReg, Register, |
| typename std::conditional<rc == kFpReg, DoubleRegister, void>::type>::type; |
| |
| // Maximum code of a gp cache register. |
| static constexpr int kMaxGpRegCode = |
| 8 * sizeof(kLiftoffAssemblerGpCacheRegs) - |
| base::bits::CountLeadingZeros(kLiftoffAssemblerGpCacheRegs); |
| // Maximum code of an fp cache register. |
| static constexpr int kMaxFpRegCode = |
| 8 * sizeof(kLiftoffAssemblerFpCacheRegs) - |
| base::bits::CountLeadingZeros(kLiftoffAssemblerFpCacheRegs); |
| // LiftoffRegister encodes both gp and fp in a unified index space. |
| // [0 .. kMaxGpRegCode] encodes gp registers, |
| // [kMaxGpRegCode+1 .. kMaxGpRegCode + kMaxFpRegCode] encodes fp registers. |
| static constexpr int kAfterMaxLiftoffGpRegCode = kMaxGpRegCode + 1; |
| static constexpr int kAfterMaxLiftoffFpRegCode = |
| kAfterMaxLiftoffGpRegCode + kMaxFpRegCode + 1; |
| static constexpr int kAfterMaxLiftoffRegCode = kAfterMaxLiftoffFpRegCode; |
| static_assert(kAfterMaxLiftoffRegCode < 256, |
| "liftoff register codes can be stored in one uint8_t"); |
| |
| class LiftoffRegister { |
| public: |
| explicit LiftoffRegister(Register reg) : LiftoffRegister(reg.code()) { |
| DCHECK_EQ(reg, gp()); |
| } |
| explicit LiftoffRegister(DoubleRegister reg) |
| : LiftoffRegister(kAfterMaxLiftoffGpRegCode + reg.code()) { |
| DCHECK_EQ(reg, fp()); |
| } |
| |
| static LiftoffRegister from_liftoff_code(int code) { |
| DCHECK_LE(0, code); |
| DCHECK_GT(kAfterMaxLiftoffRegCode, code); |
| return LiftoffRegister(code); |
| } |
| |
| static LiftoffRegister from_code(RegClass rc, int code) { |
| switch (rc) { |
| case kGpReg: |
| return LiftoffRegister(Register::from_code(code)); |
| case kFpReg: |
| return LiftoffRegister(DoubleRegister::from_code(code)); |
| default: |
| UNREACHABLE(); |
| } |
| } |
| |
| constexpr bool is_gp() const { return code_ < kAfterMaxLiftoffGpRegCode; } |
| constexpr bool is_fp() const { |
| return code_ >= kAfterMaxLiftoffGpRegCode && |
| code_ < kAfterMaxLiftoffFpRegCode; |
| } |
| |
| Register gp() const { |
| DCHECK(is_gp()); |
| return Register::from_code(code_); |
| } |
| |
| DoubleRegister fp() const { |
| DCHECK(is_fp()); |
| return DoubleRegister::from_code(code_ - kAfterMaxLiftoffGpRegCode); |
| } |
| |
| int liftoff_code() const { return code_; } |
| |
| RegClass reg_class() const { |
| DCHECK(is_gp() || is_fp()); |
| return is_gp() ? kGpReg : kFpReg; |
| } |
| |
| bool operator==(const LiftoffRegister other) const { |
| return code_ == other.code_; |
| } |
| bool operator!=(const LiftoffRegister other) const { |
| return code_ != other.code_; |
| } |
| |
| private: |
| uint8_t code_; |
| |
| explicit constexpr LiftoffRegister(uint8_t code) : code_(code) {} |
| }; |
| static_assert(IS_TRIVIALLY_COPYABLE(LiftoffRegister), |
| "LiftoffRegister can efficiently be passed by value"); |
| |
| inline std::ostream& operator<<(std::ostream& os, LiftoffRegister reg) { |
| return reg.is_gp() ? os << "gp" << reg.gp().code() |
| : os << "fp" << reg.fp().code(); |
| } |
| |
| class LiftoffRegList { |
| public: |
| static constexpr bool use_u16 = kAfterMaxLiftoffRegCode <= 16; |
| static constexpr bool use_u32 = !use_u16 && kAfterMaxLiftoffRegCode <= 32; |
| using storage_t = std::conditional< |
| use_u16, uint16_t, |
| std::conditional<use_u32, uint32_t, uint64_t>::type>::type; |
| |
| static constexpr storage_t kGpMask = storage_t{kLiftoffAssemblerGpCacheRegs}; |
| static constexpr storage_t kFpMask = storage_t{kLiftoffAssemblerFpCacheRegs} |
| << kAfterMaxLiftoffGpRegCode; |
| |
| constexpr LiftoffRegList() = default; |
| |
| Register set(Register reg) { return set(LiftoffRegister(reg)).gp(); } |
| DoubleRegister set(DoubleRegister reg) { |
| return set(LiftoffRegister(reg)).fp(); |
| } |
| |
| LiftoffRegister set(LiftoffRegister reg) { |
| regs_ |= storage_t{1} << reg.liftoff_code(); |
| return reg; |
| } |
| |
| LiftoffRegister clear(LiftoffRegister reg) { |
| regs_ &= ~(storage_t{1} << reg.liftoff_code()); |
| return reg; |
| } |
| |
| bool has(LiftoffRegister reg) const { |
| return (regs_ & (storage_t{1} << reg.liftoff_code())) != 0; |
| } |
| |
| constexpr bool is_empty() const { return regs_ == 0; } |
| |
| constexpr unsigned GetNumRegsSet() const { |
| return base::bits::CountPopulation(regs_); |
| } |
| |
| constexpr LiftoffRegList operator&(const LiftoffRegList other) const { |
| return LiftoffRegList(regs_ & other.regs_); |
| } |
| |
| constexpr LiftoffRegList operator~() const { |
| return LiftoffRegList(~regs_ & (kGpMask | kFpMask)); |
| } |
| |
| constexpr bool operator==(const LiftoffRegList other) const { |
| return regs_ == other.regs_; |
| } |
| constexpr bool operator!=(const LiftoffRegList other) const { |
| return regs_ != other.regs_; |
| } |
| |
| LiftoffRegister GetFirstRegSet() const { |
| DCHECK(!is_empty()); |
| unsigned first_code = base::bits::CountTrailingZeros(regs_); |
| return LiftoffRegister::from_liftoff_code(first_code); |
| } |
| |
| LiftoffRegister GetLastRegSet() const { |
| DCHECK(!is_empty()); |
| unsigned last_code = |
| 8 * sizeof(regs_) - 1 - base::bits::CountLeadingZeros(regs_); |
| return LiftoffRegister::from_liftoff_code(last_code); |
| } |
| |
| LiftoffRegList MaskOut(const LiftoffRegList mask) const { |
| // Masking out is guaranteed to return a correct reg list, hence no checks |
| // needed. |
| return FromBits(regs_ & ~mask.regs_); |
| } |
| |
| static LiftoffRegList FromBits(storage_t bits) { |
| DCHECK_EQ(bits, bits & (kGpMask | kFpMask)); |
| return LiftoffRegList(bits); |
| } |
| |
| template <storage_t bits> |
| static constexpr LiftoffRegList FromBits() { |
| static_assert(bits == (bits & (kGpMask | kFpMask)), "illegal reg list"); |
| return LiftoffRegList(bits); |
| } |
| |
| template <typename... Regs> |
| static LiftoffRegList ForRegs(Regs... regs) { |
| std::array<LiftoffRegister, sizeof...(regs)> regs_arr{ |
| LiftoffRegister(regs)...}; |
| LiftoffRegList list; |
| for (LiftoffRegister reg : regs_arr) list.set(reg); |
| return list; |
| } |
| |
| private: |
| storage_t regs_ = 0; |
| |
| // Unchecked constructor. Only use for valid bits. |
| explicit constexpr LiftoffRegList(storage_t bits) : regs_(bits) {} |
| }; |
| static_assert(IS_TRIVIALLY_COPYABLE(LiftoffRegList), |
| "LiftoffRegList can be passed by value"); |
| |
| static constexpr LiftoffRegList kGpCacheRegList = |
| LiftoffRegList::FromBits<LiftoffRegList::kGpMask>(); |
| static constexpr LiftoffRegList kFpCacheRegList = |
| LiftoffRegList::FromBits<LiftoffRegList::kFpMask>(); |
| |
| static constexpr LiftoffRegList GetCacheRegList(RegClass rc) { |
| return rc == kGpReg ? kGpCacheRegList : kFpCacheRegList; |
| } |
| |
| } // namespace wasm |
| } // namespace internal |
| } // namespace v8 |
| |
| #endif // V8_WASM_BASELINE_LIFTOFF_REGISTER_H_ |