1//===-- llvm/Support/CodeGen.h - CodeGen Concepts ---------------*- 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// This file define some types which define code generation concepts. For
10// example, relocation model.
11//
12//===----------------------------------------------------------------------===//
13
14#ifndef LLVM_SUPPORT_CODEGEN_H
15#define LLVM_SUPPORT_CODEGEN_H
16
17#include <cstdint>
18#include <optional>
19
20namespace llvm {
21
22 // Relocation model types.
23 namespace Reloc {
24 // Cannot be named PIC due to collision with -DPIC
25 enum Model { Static, PIC_, DynamicNoPIC, ROPI, RWPI, ROPI_RWPI };
26 }
27
28 // Code model types.
29 namespace CodeModel {
30 // Sync changes with CodeGenCWrappers.h.
31 enum Model { Tiny, Small, Kernel, Medium, Large };
32 }
33
34 namespace PICLevel {
35 // This is used to map -fpic/-fPIC.
36 enum Level { NotPIC=0, SmallPIC=1, BigPIC=2 };
37 }
38
39 namespace PIELevel {
40 enum Level { Default=0, Small=1, Large=2 };
41 }
42
43 // TLS models.
44 namespace TLSModel {
45 enum Model {
46 GeneralDynamic,
47 LocalDynamic,
48 InitialExec,
49 LocalExec
50 };
51 }
52
53 enum class ExceptionHandling {
54 None, ///< No exception support
55 DwarfCFI, ///< DWARF-like instruction based exceptions
56 SjLj, ///< setjmp/longjmp based exceptions
57 ARM, ///< ARM EHABI
58 WinEH, ///< Windows Exception Handling
59 Wasm, ///< WebAssembly Exception Handling
60 AIX, ///< AIX Exception Handling
61 ZOS, ///< z/OS MVS Exception Handling. Very similar to DwarfCFI, but the
62 ///< PPA1 is used instead of an .eh_frame section.
63 };
64
65 namespace FloatABI {
66 enum ABIType {
67 Default, // Target-specific (either soft or hard depending on triple, etc).
68 Soft, // Soft float.
69 Hard // Hard float.
70 };
71 }
72
73 enum class EABI {
74 Unknown,
75 Default, // Default means not specified
76 EABI4, // Target-specific (either 4, 5 or gnu depending on triple).
77 EABI5,
78 GNU
79 };
80
81 /// Code generation optimization level.
82 enum class CodeGenOptLevel {
83 None = 0, ///< -O0
84 Less = 1, ///< -O1
85 Default = 2, ///< -O2, -Os, -Oz
86 Aggressive = 3 ///< -O3
87 };
88
89 namespace CodeGenOpt {
90 /// Get the \c Level identified by the integer \p OL.
91 ///
92 /// Returns std::nullopt if \p OL is invalid.
93 inline std::optional<CodeGenOptLevel> getLevel(int OL) {
94 if (OL < 0 || OL > 3)
95 return std::nullopt;
96 return static_cast<CodeGenOptLevel>(OL);
97 }
98 /// Parse \p C as a single digit integer and get matching \c CodeGenLevel.
99 ///
100 /// Returns std::nullopt if the input is not a valid optimization level.
101 inline std::optional<CodeGenOptLevel> parseLevel(char C) {
102 if (C < '0')
103 return std::nullopt;
104 return getLevel(OL: static_cast<int>(C - '0'));
105 }
106 } // namespace CodeGenOpt
107
108 /// These enums are meant to be passed into addPassesToEmitFile to indicate
109 /// what type of file to emit, and returned by it to indicate what type of
110 /// file could actually be made.
111 enum class CodeGenFileType {
112 AssemblyFile,
113 ObjectFile,
114 Null // Do not emit any output.
115 };
116
117 // Specify what functions should keep the frame pointer.
118 enum class FramePointerKind {
119 None,
120 NonLeaf,
121 All,
122 Reserved,
123 NonLeafNoReserve
124 };
125
126 // Specify what type of zeroing callee-used registers.
127 namespace ZeroCallUsedRegs {
128 const unsigned ONLY_USED = 1U << 1;
129 const unsigned ONLY_GPR = 1U << 2;
130 const unsigned ONLY_ARG = 1U << 3;
131
132 enum class ZeroCallUsedRegsKind : unsigned int {
133 // Don't zero any call-used regs.
134 Skip = 1U << 0,
135 // Only zeros call-used GPRs used in the fn and pass args.
136 UsedGPRArg = ONLY_USED | ONLY_GPR | ONLY_ARG,
137 // Only zeros call-used GPRs used in the fn.
138 UsedGPR = ONLY_USED | ONLY_GPR,
139 // Only zeros call-used regs used in the fn and pass args.
140 UsedArg = ONLY_USED | ONLY_ARG,
141 // Only zeros call-used regs used in the fn.
142 Used = ONLY_USED,
143 // Zeros all call-used GPRs that pass args.
144 AllGPRArg = ONLY_GPR | ONLY_ARG,
145 // Zeros all call-used GPRs.
146 AllGPR = ONLY_GPR,
147 // Zeros all call-used regs that pass args.
148 AllArg = ONLY_ARG,
149 // Zeros all call-used regs.
150 All = 0,
151 };
152 } // namespace ZeroCallUsedRegs
153
154 enum class UWTableKind {
155 None = 0, ///< No unwind table requested
156 Sync = 1, ///< "Synchronous" unwind tables
157 Async = 2, ///< "Asynchronous" unwind tables (instr precise)
158 Default = 2,
159 };
160
161 enum class FunctionReturnThunksKind : unsigned int {
162 Keep = 0, ///< No function return thunk.
163 Extern = 1, ///< Replace returns with jump to thunk, don't emit thunk.
164 Invalid = 2, ///< Not used.
165 };
166
167 enum class WinX64EHUnwindV2Mode {
168 // Don't use unwind v2 (i.e., use v1).
169 Disabled = 0,
170 // Use unwind v2 here possible, otherwise fallback to v1.
171 BestEffort = 1,
172 // Use unwind v2 everywhere, otherwise raise an error.
173 Required = 2,
174 };
175
176 enum class ControlFlowGuardMode {
177 // Don't enable Control Flow Guard.
178 Disabled = 0,
179 // Emit the Control Flow Guard tables in the binary, but don't emit any
180 // checks.
181 TableOnly = 1,
182 // Enable Control Flow Guard checks and emit the tables.
183 Enabled = 2,
184 };
185
186 } // namespace llvm
187
188#endif
189