1//===--- Integral.h - Wrapper for numeric types for the VM ------*- 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// Defines the VM types and helpers operating on types.
10//
11//===----------------------------------------------------------------------===//
12
13#ifndef LLVM_CLANG_AST_INTERP_INTEGRAL_AP_H
14#define LLVM_CLANG_AST_INTERP_INTEGRAL_AP_H
15
16#include "clang/AST/APValue.h"
17#include "clang/AST/ComparisonCategories.h"
18#include "llvm/ADT/APSInt.h"
19#include "llvm/Support/MathExtras.h"
20#include "llvm/Support/raw_ostream.h"
21#include <cstddef>
22#include <cstdint>
23
24#include "Primitives.h"
25
26namespace clang {
27namespace interp {
28
29using APInt = llvm::APInt;
30using APSInt = llvm::APSInt;
31template <unsigned Bits, bool Signed> class Integral;
32
33template <bool Signed> class IntegralAP final {
34private:
35 friend IntegralAP<!Signed>;
36 APInt V;
37
38 template <typename T, bool InputSigned>
39 static T truncateCast(const APInt &V) {
40 constexpr unsigned BitSize = sizeof(T) * 8;
41 if (BitSize >= V.getBitWidth()) {
42 APInt Extended;
43 if constexpr (InputSigned)
44 Extended = V.sext(width: BitSize);
45 else
46 Extended = V.zext(width: BitSize);
47 return std::is_signed_v<T> ? Extended.getSExtValue()
48 : Extended.getZExtValue();
49 }
50
51 return std::is_signed_v<T> ? V.trunc(width: BitSize).getSExtValue()
52 : V.trunc(width: BitSize).getZExtValue();
53 }
54
55public:
56 using AsUnsigned = IntegralAP<false>;
57
58 template <typename T>
59 IntegralAP(T Value, unsigned BitWidth)
60 : V(APInt(BitWidth, static_cast<uint64_t>(Value), Signed)) {}
61
62 IntegralAP(APInt V) : V(V) {}
63 /// Arbitrary value for uninitialized variables.
64 IntegralAP() : IntegralAP(-1, 1024) {}
65
66 IntegralAP operator-() const { return IntegralAP(-V); }
67 IntegralAP operator-(const IntegralAP &Other) const {
68 return IntegralAP(V - Other.V);
69 }
70 bool operator>(const IntegralAP &RHS) const {
71 if constexpr (Signed)
72 return V.ugt(RHS.V);
73 return V.sgt(RHS.V);
74 }
75 bool operator>=(IntegralAP RHS) const {
76 if constexpr (Signed)
77 return V.uge(RHS.V);
78 return V.sge(RHS.V);
79 }
80 bool operator<(IntegralAP RHS) const {
81 if constexpr (Signed)
82 return V.slt(RHS.V);
83 return V.slt(RHS.V);
84 }
85 bool operator<=(IntegralAP RHS) const {
86 if constexpr (Signed)
87 return V.ult(RHS.V);
88 return V.ult(RHS.V);
89 }
90
91 template <typename Ty, typename = std::enable_if_t<std::is_integral_v<Ty>>>
92 explicit operator Ty() const {
93 return truncateCast<Ty, Signed>(V);
94 }
95
96 template <typename T> static IntegralAP from(T Value, unsigned NumBits = 0) {
97 assert(NumBits > 0);
98 APInt Copy = APInt(NumBits, static_cast<uint64_t>(Value), Signed);
99
100 return IntegralAP<Signed>(Copy);
101 }
102
103 template <bool InputSigned>
104 static IntegralAP from(IntegralAP<InputSigned> V, unsigned NumBits = 0) {
105 if (NumBits == 0)
106 NumBits = V.bitWidth();
107
108 if constexpr (InputSigned)
109 return IntegralAP<Signed>(V.V.sextOrTrunc(NumBits));
110 return IntegralAP<Signed>(V.V.zextOrTrunc(NumBits));
111 }
112
113 template <unsigned Bits, bool InputSigned>
114 static IntegralAP from(Integral<Bits, InputSigned> I, unsigned BitWidth) {
115 APInt Copy = APInt(BitWidth, static_cast<uint64_t>(I), InputSigned);
116
117 return IntegralAP<Signed>(Copy);
118 }
119
120 static IntegralAP zero(int32_t BitWidth) {
121 APInt V = APInt(BitWidth, 0LL, Signed);
122 return IntegralAP(V);
123 }
124
125 constexpr unsigned bitWidth() const { return V.getBitWidth(); }
126
127 APSInt toAPSInt(unsigned Bits = 0) const {
128 if (Bits == 0)
129 Bits = bitWidth();
130
131 if constexpr (Signed)
132 return APSInt(V.sext(width: Bits), !Signed);
133 else
134 return APSInt(V.zext(width: Bits), !Signed);
135 }
136 APValue toAPValue() const { return APValue(toAPSInt()); }
137
138 bool isZero() const { return V.isZero(); }
139 bool isPositive() const { return V.isNonNegative(); }
140 bool isNegative() const { return !V.isNonNegative(); }
141 bool isMin() const { return V.isMinValue(); }
142 bool isMax() const { return V.isMaxValue(); }
143 static constexpr bool isSigned() { return Signed; }
144 bool isMinusOne() const { return Signed && V == -1; }
145
146 unsigned countLeadingZeros() const { return V.countl_zero(); }
147
148 void print(llvm::raw_ostream &OS) const { OS << V; }
149 std::string toDiagnosticString(const ASTContext &Ctx) const {
150 std::string NameStr;
151 llvm::raw_string_ostream OS(NameStr);
152 print(OS);
153 return NameStr;
154 }
155
156 IntegralAP truncate(unsigned BitWidth) const {
157 if constexpr (Signed)
158 return IntegralAP(V.trunc(width: BitWidth).sextOrTrunc(width: this->bitWidth()));
159 else
160 return IntegralAP(V.trunc(width: BitWidth).zextOrTrunc(width: this->bitWidth()));
161 }
162
163 IntegralAP<false> toUnsigned() const {
164 APInt Copy = V;
165 return IntegralAP<false>(Copy);
166 }
167
168 ComparisonCategoryResult compare(const IntegralAP &RHS) const {
169 assert(Signed == RHS.isSigned());
170 assert(bitWidth() == RHS.bitWidth());
171 if constexpr (Signed) {
172 if (V.slt(RHS.V))
173 return ComparisonCategoryResult::Less;
174 if (V.sgt(RHS.V))
175 return ComparisonCategoryResult::Greater;
176 return ComparisonCategoryResult::Equal;
177 }
178
179 assert(!Signed);
180 if (V.ult(RHS.V))
181 return ComparisonCategoryResult::Less;
182 if (V.ugt(RHS.V))
183 return ComparisonCategoryResult::Greater;
184 return ComparisonCategoryResult::Equal;
185 }
186
187 static bool increment(IntegralAP A, IntegralAP *R) {
188 IntegralAP<Signed> One(1, A.bitWidth());
189 return add(A, B: One, OpBits: A.bitWidth() + 1, R);
190 }
191
192 static bool decrement(IntegralAP A, IntegralAP *R) {
193 IntegralAP<Signed> One(1, A.bitWidth());
194 return sub(A, B: One, OpBits: A.bitWidth() + 1, R);
195 }
196
197 static bool add(IntegralAP A, IntegralAP B, unsigned OpBits, IntegralAP *R) {
198 return CheckAddSubMulUB<std::plus>(A, B, OpBits, R);
199 }
200
201 static bool sub(IntegralAP A, IntegralAP B, unsigned OpBits, IntegralAP *R) {
202 return CheckAddSubMulUB<std::minus>(A, B, OpBits, R);
203 }
204
205 static bool mul(IntegralAP A, IntegralAP B, unsigned OpBits, IntegralAP *R) {
206 return CheckAddSubMulUB<std::multiplies>(A, B, OpBits, R);
207 }
208
209 static bool rem(IntegralAP A, IntegralAP B, unsigned OpBits, IntegralAP *R) {
210 if constexpr (Signed)
211 *R = IntegralAP(A.V.srem(B.V));
212 else
213 *R = IntegralAP(A.V.urem(B.V));
214 return false;
215 }
216
217 static bool div(IntegralAP A, IntegralAP B, unsigned OpBits, IntegralAP *R) {
218 if constexpr (Signed)
219 *R = IntegralAP(A.V.sdiv(B.V));
220 else
221 *R = IntegralAP(A.V.udiv(B.V));
222 return false;
223 }
224
225 static bool bitAnd(IntegralAP A, IntegralAP B, unsigned OpBits,
226 IntegralAP *R) {
227 *R = IntegralAP(A.V & B.V);
228 return false;
229 }
230
231 static bool bitOr(IntegralAP A, IntegralAP B, unsigned OpBits,
232 IntegralAP *R) {
233 *R = IntegralAP(A.V | B.V);
234 return false;
235 }
236
237 static bool bitXor(IntegralAP A, IntegralAP B, unsigned OpBits,
238 IntegralAP *R) {
239 *R = IntegralAP(A.V ^ B.V);
240 return false;
241 }
242
243 static bool neg(const IntegralAP &A, IntegralAP *R) {
244 APInt AI = A.V;
245 AI.negate();
246 *R = IntegralAP(AI);
247 return false;
248 }
249
250 static bool comp(IntegralAP A, IntegralAP *R) {
251 *R = IntegralAP(~A.V);
252 return false;
253 }
254
255 static void shiftLeft(const IntegralAP A, const IntegralAP B, unsigned OpBits,
256 IntegralAP *R) {
257 *R = IntegralAP(A.V.shl(B.V.getZExtValue()));
258 }
259
260 static void shiftRight(const IntegralAP A, const IntegralAP B,
261 unsigned OpBits, IntegralAP *R) {
262 unsigned ShiftAmount = B.V.getZExtValue();
263 if constexpr (Signed)
264 *R = IntegralAP(A.V.ashr(ShiftAmount));
265 else
266 *R = IntegralAP(A.V.lshr(ShiftAmount));
267 }
268
269 // === Serialization support ===
270 size_t bytesToSerialize() const {
271 // 4 bytes for the BitWidth followed by N bytes for the actual APInt.
272 return sizeof(uint32_t) + (V.getBitWidth() / CHAR_BIT);
273 }
274
275 void serialize(std::byte *Buff) const {
276 assert(V.getBitWidth() < std::numeric_limits<uint8_t>::max());
277 uint32_t BitWidth = V.getBitWidth();
278
279 std::memcpy(dest: Buff, src: &BitWidth, n: sizeof(uint32_t));
280 llvm::StoreIntToMemory(IntVal: V, Dst: (uint8_t *)(Buff + sizeof(uint32_t)),
281 StoreBytes: BitWidth / CHAR_BIT);
282 }
283
284 static IntegralAP<Signed> deserialize(const std::byte *Buff) {
285 uint32_t BitWidth;
286 std::memcpy(dest: &BitWidth, src: Buff, n: sizeof(uint32_t));
287 IntegralAP<Signed> Val(APInt(BitWidth, 0ull, !Signed));
288
289 llvm::LoadIntFromMemory(IntVal&: Val.V, Src: (const uint8_t *)Buff + sizeof(uint32_t),
290 LoadBytes: BitWidth / CHAR_BIT);
291 return Val;
292 }
293
294private:
295 template <template <typename T> class Op>
296 static bool CheckAddSubMulUB(const IntegralAP &A, const IntegralAP &B,
297 unsigned BitWidth, IntegralAP *R) {
298 if constexpr (!Signed) {
299 R->V = Op<APInt>{}(A.V, B.V);
300 return false;
301 }
302
303 const APSInt &LHS = A.toAPSInt();
304 const APSInt &RHS = B.toAPSInt();
305 APSInt Value = Op<APSInt>{}(LHS.extend(width: BitWidth), RHS.extend(width: BitWidth));
306 APSInt Result = Value.trunc(width: LHS.getBitWidth());
307 R->V = Result;
308
309 return Result.extend(width: BitWidth) != Value;
310 }
311};
312
313template <bool Signed>
314inline llvm::raw_ostream &operator<<(llvm::raw_ostream &OS,
315 IntegralAP<Signed> I) {
316 I.print(OS);
317 return OS;
318}
319
320template <bool Signed>
321IntegralAP<Signed> getSwappedBytes(IntegralAP<Signed> F) {
322 return F;
323}
324
325} // namespace interp
326} // namespace clang
327
328#endif
329

source code of clang/lib/AST/Interp/IntegralAP.h