| //===-- lldb_InstructionUtils.h ---------------------------------*- C++ -*-===// |
| // |
| // The LLVM Compiler Infrastructure |
| // |
| // This file is distributed under the University of Illinois Open Source |
| // License. See LICENSE.TXT for details. |
| // |
| //===----------------------------------------------------------------------===// |
| |
| #ifndef lldb_InstructionUtils_h_ |
| #define lldb_InstructionUtils_h_ |
| |
| // Common utilities for manipulating instruction bit fields. |
| |
| namespace lldb_private { |
| |
| static inline uint32_t |
| Bits32 (const uint32_t value, const uint32_t msbit, const uint32_t lsbit) |
| { |
| assert(msbit < 32 && lsbit <= msbit); |
| return (value >> lsbit) & ((1u << (msbit - lsbit + 1)) - 1); |
| } |
| |
| static inline void |
| SetBits32(uint32_t &bits, unsigned msbit, unsigned lsbit, unsigned val) |
| { |
| assert(msbit < 32 && lsbit < 32 && msbit >= lsbit); |
| uint32_t mask = ((1 << (msbit - lsbit + 1)) - 1); |
| bits &= ~(mask << lsbit); |
| bits |= (val & mask) << lsbit; |
| } |
| |
| // Create a mask that starts at bit zero and includes "bit" |
| static inline uint64_t |
| MaskUpToBit (const uint64_t bit) |
| { |
| return (1ull << (bit + 1ull)) - 1ull; |
| } |
| |
| // Returns an integer result equal to the number of bits of x that are ones. |
| static inline uint32_t |
| BitCount (uint64_t x) |
| { |
| // c accumulates the total bits set in x |
| uint32_t c; |
| for (c = 0; x; ++c) |
| { |
| x &= x - 1; // clear the least significant bit set |
| } |
| return c; |
| } |
| |
| static inline bool |
| BitIsSet (const uint64_t value, const uint64_t bit) |
| { |
| return (value & (1ull << bit)) != 0; |
| } |
| |
| static inline bool |
| BitIsClear (const uint64_t value, const uint64_t bit) |
| { |
| return (value & (1ull << bit)) == 0; |
| } |
| |
| static inline uint64_t |
| UnsignedBits (const uint64_t value, const uint64_t msbit, const uint64_t lsbit) |
| { |
| uint64_t result = value >> lsbit; |
| result &= MaskUpToBit (msbit - lsbit); |
| return result; |
| } |
| |
| static inline int64_t |
| SignedBits (const uint64_t value, const uint64_t msbit, const uint64_t lsbit) |
| { |
| uint64_t result = UnsignedBits (value, msbit, lsbit); |
| if (BitIsSet(value, msbit)) |
| { |
| // Sign extend |
| result |= ~MaskUpToBit (msbit - lsbit); |
| } |
| return result; |
| } |
| |
| } // namespace lldb_private |
| |
| #endif // lldb_InstructionUtils_h_ |