1 | //===--- Floating.h - Types for the constexpr 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_FLOATING_H |
14 | #define LLVM_CLANG_AST_INTERP_FLOATING_H |
15 | |
16 | #include "Primitives.h" |
17 | #include "clang/AST/APValue.h" |
18 | #include "llvm/ADT/APFloat.h" |
19 | |
20 | namespace clang { |
21 | namespace interp { |
22 | |
23 | using APFloat = llvm::APFloat; |
24 | using APSInt = llvm::APSInt; |
25 | |
26 | class Floating final { |
27 | private: |
28 | // The underlying value storage. |
29 | APFloat F; |
30 | |
31 | public: |
32 | /// Zero-initializes a Floating. |
33 | Floating() : F(0.0f) {} |
34 | Floating(const APFloat &F) : F(F) {} |
35 | |
36 | // Static constructors for special floating point values. |
37 | static Floating getInf(const llvm::fltSemantics &Sem) { |
38 | return Floating(APFloat::getInf(Sem)); |
39 | } |
40 | const APFloat &getAPFloat() const { return F; } |
41 | |
42 | bool operator<(Floating RHS) const { return F < RHS.F; } |
43 | bool operator>(Floating RHS) const { return F > RHS.F; } |
44 | bool operator<=(Floating RHS) const { return F <= RHS.F; } |
45 | bool operator>=(Floating RHS) const { return F >= RHS.F; } |
46 | bool operator==(Floating RHS) const { return F == RHS.F; } |
47 | bool operator!=(Floating RHS) const { return F != RHS.F; } |
48 | Floating operator-() const { return Floating(-F); } |
49 | |
50 | APFloat::opStatus convertToInteger(APSInt &Result) const { |
51 | bool IsExact; |
52 | return F.convertToInteger(Result, RM: llvm::APFloat::rmTowardZero, IsExact: &IsExact); |
53 | } |
54 | |
55 | Floating toSemantics(const llvm::fltSemantics *Sem, |
56 | llvm::RoundingMode RM) const { |
57 | APFloat Copy = F; |
58 | bool LosesInfo; |
59 | Copy.convert(ToSemantics: *Sem, RM, losesInfo: &LosesInfo); |
60 | (void)LosesInfo; |
61 | return Floating(Copy); |
62 | } |
63 | |
64 | /// Convert this Floating to one with the same semantics as \Other. |
65 | Floating toSemantics(const Floating &Other, llvm::RoundingMode RM) const { |
66 | return toSemantics(Sem: &Other.F.getSemantics(), RM); |
67 | } |
68 | |
69 | APSInt toAPSInt(unsigned NumBits = 0) const { |
70 | return APSInt(F.bitcastToAPInt()); |
71 | } |
72 | APValue toAPValue(const ASTContext &) const { return APValue(F); } |
73 | void print(llvm::raw_ostream &OS) const { |
74 | // Can't use APFloat::print() since it appends a newline. |
75 | SmallVector<char, 16> Buffer; |
76 | F.toString(Str&: Buffer); |
77 | OS << Buffer; |
78 | } |
79 | std::string toDiagnosticString(const ASTContext &Ctx) const { |
80 | std::string NameStr; |
81 | llvm::raw_string_ostream OS(NameStr); |
82 | print(OS); |
83 | return NameStr; |
84 | } |
85 | |
86 | unsigned bitWidth() const { return F.semanticsSizeInBits(F.getSemantics()); } |
87 | |
88 | bool isSigned() const { return true; } |
89 | bool isNegative() const { return F.isNegative(); } |
90 | bool isZero() const { return F.isZero(); } |
91 | bool isNonZero() const { return F.isNonZero(); } |
92 | bool isMin() const { return F.isSmallest(); } |
93 | bool isMinusOne() const { return F.isExactlyValue(V: -1.0); } |
94 | bool isNan() const { return F.isNaN(); } |
95 | bool isSignaling() const { return F.isSignaling(); } |
96 | bool isInf() const { return F.isInfinity(); } |
97 | bool isFinite() const { return F.isFinite(); } |
98 | bool isNormal() const { return F.isNormal(); } |
99 | bool isDenormal() const { return F.isDenormal(); } |
100 | llvm::FPClassTest classify() const { return F.classify(); } |
101 | APFloat::fltCategory getCategory() const { return F.getCategory(); } |
102 | |
103 | ComparisonCategoryResult compare(const Floating &RHS) const { |
104 | llvm::APFloatBase::cmpResult CmpRes = F.compare(RHS: RHS.F); |
105 | switch (CmpRes) { |
106 | case llvm::APFloatBase::cmpLessThan: |
107 | return ComparisonCategoryResult::Less; |
108 | case llvm::APFloatBase::cmpEqual: |
109 | return ComparisonCategoryResult::Equal; |
110 | case llvm::APFloatBase::cmpGreaterThan: |
111 | return ComparisonCategoryResult::Greater; |
112 | case llvm::APFloatBase::cmpUnordered: |
113 | return ComparisonCategoryResult::Unordered; |
114 | } |
115 | llvm_unreachable("Inavlid cmpResult value" ); |
116 | } |
117 | |
118 | static APFloat::opStatus fromIntegral(APSInt Val, |
119 | const llvm::fltSemantics &Sem, |
120 | llvm::RoundingMode RM, |
121 | Floating &Result) { |
122 | APFloat F = APFloat(Sem); |
123 | APFloat::opStatus Status = F.convertFromAPInt(Input: Val, IsSigned: Val.isSigned(), RM); |
124 | Result = Floating(F); |
125 | return Status; |
126 | } |
127 | |
128 | static Floating bitcastFromMemory(const std::byte *Buff, |
129 | const llvm::fltSemantics &Sem) { |
130 | size_t Size = APFloat::semanticsSizeInBits(Sem); |
131 | llvm::APInt API(Size, true); |
132 | llvm::LoadIntFromMemory(IntVal&: API, Src: (const uint8_t *)Buff, LoadBytes: Size / 8); |
133 | |
134 | return Floating(APFloat(Sem, API)); |
135 | } |
136 | |
137 | void bitcastToMemory(std::byte *Buff) const { |
138 | llvm::APInt API = F.bitcastToAPInt(); |
139 | llvm::StoreIntToMemory(IntVal: API, Dst: (uint8_t *)Buff, StoreBytes: bitWidth() / 8); |
140 | } |
141 | |
142 | // === Serialization support === |
143 | size_t bytesToSerialize() const { |
144 | return sizeof(llvm::fltSemantics *) + |
145 | (APFloat::semanticsSizeInBits(F.getSemantics()) / 8); |
146 | } |
147 | |
148 | void serialize(std::byte *Buff) const { |
149 | // Semantics followed by an APInt. |
150 | *reinterpret_cast<const llvm::fltSemantics **>(Buff) = &F.getSemantics(); |
151 | |
152 | llvm::APInt API = F.bitcastToAPInt(); |
153 | llvm::StoreIntToMemory(IntVal: API, Dst: (uint8_t *)(Buff + sizeof(void *)), |
154 | StoreBytes: bitWidth() / 8); |
155 | } |
156 | |
157 | static Floating deserialize(const std::byte *Buff) { |
158 | const llvm::fltSemantics *Sem; |
159 | std::memcpy(dest: (void *)&Sem, src: Buff, n: sizeof(void *)); |
160 | return bitcastFromMemory(Buff: Buff + sizeof(void *), Sem: *Sem); |
161 | } |
162 | |
163 | static Floating abs(const Floating &F) { |
164 | APFloat V = F.F; |
165 | if (V.isNegative()) |
166 | V.changeSign(); |
167 | return Floating(V); |
168 | } |
169 | |
170 | // ------- |
171 | |
172 | static APFloat::opStatus add(const Floating &A, const Floating &B, |
173 | llvm::RoundingMode RM, Floating *R) { |
174 | *R = Floating(A.F); |
175 | return R->F.add(RHS: B.F, RM); |
176 | } |
177 | |
178 | static APFloat::opStatus increment(const Floating &A, llvm::RoundingMode RM, |
179 | Floating *R) { |
180 | APFloat One(A.F.getSemantics(), 1); |
181 | *R = Floating(A.F); |
182 | return R->F.add(RHS: One, RM); |
183 | } |
184 | |
185 | static APFloat::opStatus sub(const Floating &A, const Floating &B, |
186 | llvm::RoundingMode RM, Floating *R) { |
187 | *R = Floating(A.F); |
188 | return R->F.subtract(RHS: B.F, RM); |
189 | } |
190 | |
191 | static APFloat::opStatus decrement(const Floating &A, llvm::RoundingMode RM, |
192 | Floating *R) { |
193 | APFloat One(A.F.getSemantics(), 1); |
194 | *R = Floating(A.F); |
195 | return R->F.subtract(RHS: One, RM); |
196 | } |
197 | |
198 | static APFloat::opStatus mul(const Floating &A, const Floating &B, |
199 | llvm::RoundingMode RM, Floating *R) { |
200 | *R = Floating(A.F); |
201 | return R->F.multiply(RHS: B.F, RM); |
202 | } |
203 | |
204 | static APFloat::opStatus div(const Floating &A, const Floating &B, |
205 | llvm::RoundingMode RM, Floating *R) { |
206 | *R = Floating(A.F); |
207 | return R->F.divide(RHS: B.F, RM); |
208 | } |
209 | |
210 | static bool neg(const Floating &A, Floating *R) { |
211 | *R = -A; |
212 | return false; |
213 | } |
214 | }; |
215 | |
216 | llvm::raw_ostream &operator<<(llvm::raw_ostream &OS, Floating F); |
217 | Floating getSwappedBytes(Floating F); |
218 | |
219 | } // namespace interp |
220 | } // namespace clang |
221 | |
222 | #endif |
223 | |