1//===-- InstructionUtils.h --------------------------------------*- C++ -*-===//
2//
3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4// See https://llvm.org/LICENSE.txt for license information.
5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6//
7//===----------------------------------------------------------------------===//
8
9#ifndef LLDB_SOURCE_PLUGINS_PROCESS_UTILITY_INSTRUCTIONUTILS_H
10#define LLDB_SOURCE_PLUGINS_PROCESS_UTILITY_INSTRUCTIONUTILS_H
11
12#include <cassert>
13#include <cstdint>
14
15// Common utilities for manipulating instruction bit fields.
16
17namespace lldb_private {
18
19// Return the bit field(s) from the most significant bit (msbit) to the
20// least significant bit (lsbit) of a 64-bit unsigned value.
21static inline uint64_t Bits64(const uint64_t bits, const uint32_t msbit,
22 const uint32_t lsbit) {
23 assert(msbit < 64 && lsbit <= msbit);
24 return (bits >> lsbit) & ((1ull << (msbit - lsbit + 1)) - 1);
25}
26
27// Return the bit field(s) from the most significant bit (msbit) to the
28// least significant bit (lsbit) of a 32-bit unsigned value.
29static inline uint32_t Bits32(const uint32_t bits, const uint32_t msbit,
30 const uint32_t lsbit) {
31 assert(msbit < 32 && lsbit <= msbit);
32 return (bits >> lsbit) & ((1u << (msbit - lsbit + 1)) - 1);
33}
34
35// Return the bit value from the 'bit' position of a 32-bit unsigned value.
36static inline uint32_t Bit32(const uint32_t bits, const uint32_t bit) {
37 return (bits >> bit) & 1u;
38}
39
40static inline uint64_t Bit64(const uint64_t bits, const uint32_t bit) {
41 return (bits >> bit) & 1ull;
42}
43
44// Set the bit field(s) from the most significant bit (msbit) to the
45// least significant bit (lsbit) of a 32-bit unsigned value to 'val'.
46static inline void SetBits32(uint32_t &bits, const uint32_t msbit,
47 const uint32_t lsbit, const uint32_t val) {
48 assert(msbit < 32 && lsbit < 32 && msbit >= lsbit);
49 uint32_t mask = ((1u << (msbit - lsbit + 1)) - 1);
50 bits &= ~(mask << lsbit);
51 bits |= (val & mask) << lsbit;
52}
53
54// Set the 'bit' position of a 32-bit unsigned value to 'val'.
55static inline void SetBit32(uint32_t &bits, const uint32_t bit,
56 const uint32_t val) {
57 SetBits32(bits, msbit: bit, lsbit: bit, val);
58}
59
60// Rotate a 32-bit unsigned value right by the specified amount.
61static inline uint32_t Rotr32(uint32_t bits, uint32_t amt) {
62 assert(amt < 32 && "Invalid rotate amount");
63 return (bits >> amt) | (bits << ((32 - amt) & 31));
64}
65
66// Rotate a 32-bit unsigned value left by the specified amount.
67static inline uint32_t Rotl32(uint32_t bits, uint32_t amt) {
68 assert(amt < 32 && "Invalid rotate amount");
69 return (bits << amt) | (bits >> ((32 - amt) & 31));
70}
71
72// Create a mask that starts at bit zero and includes "bit"
73static inline uint64_t MaskUpToBit(const uint64_t bit) {
74 if (bit >= 63)
75 return -1ll;
76 return (1ull << (bit + 1ull)) - 1ull;
77}
78
79// Return an integer result equal to the number of bits of x that are ones.
80static inline uint32_t BitCount(uint64_t x) {
81 // c accumulates the total bits set in x
82 uint32_t c;
83 for (c = 0; x; ++c) {
84 x &= x - 1; // clear the least significant bit set
85 }
86 return c;
87}
88
89static inline bool BitIsSet(const uint64_t value, const uint64_t bit) {
90 return (value & (1ull << bit)) != 0;
91}
92
93static inline bool BitIsClear(const uint64_t value, const uint64_t bit) {
94 return (value & (1ull << bit)) == 0;
95}
96
97static inline uint64_t UnsignedBits(const uint64_t value, const uint64_t msbit,
98 const uint64_t lsbit) {
99 uint64_t result = value >> lsbit;
100 result &= MaskUpToBit(bit: msbit - lsbit);
101 return result;
102}
103
104static inline int64_t SignedBits(const uint64_t value, const uint64_t msbit,
105 const uint64_t lsbit) {
106 uint64_t result = UnsignedBits(value, msbit, lsbit);
107 if (BitIsSet(value, bit: msbit)) {
108 // Sign extend
109 result |= ~MaskUpToBit(bit: msbit - lsbit);
110 }
111 return result;
112}
113
114} // namespace lldb_private
115
116#endif // LLDB_SOURCE_PLUGINS_PROCESS_UTILITY_INSTRUCTIONUTILS_H
117

source code of lldb/source/Plugins/Process/Utility/InstructionUtils.h