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 namespace llvm {
18 
19   // Relocation model types.
20   namespace Reloc {
21     // Cannot be named PIC due to collision with -DPIC
22     enum Model { Static, PIC_, DynamicNoPIC, ROPI, RWPI, ROPI_RWPI };
23   }
24 
25   // Code model types.
26   namespace CodeModel {
27     // Sync changes with CodeGenCWrappers.h.
28     enum Model { Tiny, Small, Kernel, Medium, Large };
29   }
30 
31   namespace PICLevel {
32     // This is used to map -fpic/-fPIC.
33     enum Level { NotPIC=0, SmallPIC=1, BigPIC=2 };
34   }
35 
36   namespace PIELevel {
37     enum Level { Default=0, Small=1, Large=2 };
38   }
39 
40   // TLS models.
41   namespace TLSModel {
42     enum Model {
43       GeneralDynamic,
44       LocalDynamic,
45       InitialExec,
46       LocalExec
47     };
48   }
49 
50   // Code generation optimization level.
51   namespace CodeGenOpt {
52     enum Level {
53       None = 0,      // -O0
54       Less = 1,      // -O1
55       Default = 2,   // -O2, -Os
56       Aggressive = 3 // -O3
57     };
58   }
59 
60   /// These enums are meant to be passed into addPassesToEmitFile to indicate
61   /// what type of file to emit, and returned by it to indicate what type of
62   /// file could actually be made.
63   enum CodeGenFileType {
64     CGFT_AssemblyFile,
65     CGFT_ObjectFile,
66     CGFT_Null         // Do not emit any output.
67   };
68 
69   // Specify what functions should keep the frame pointer.
70   enum class FramePointerKind { None, NonLeaf, All };
71 
72   // Specify what type of zeroing callee-used registers.
73   namespace ZeroCallUsedRegs {
74   const unsigned ONLY_USED = 1U << 1;
75   const unsigned ONLY_GPR = 1U << 2;
76   const unsigned ONLY_ARG = 1U << 3;
77 
78   enum class ZeroCallUsedRegsKind : unsigned int {
79     // Don't zero any call-used regs.
80     Skip = 1U << 0,
81     // Only zeros call-used GPRs used in the fn and pass args.
82     UsedGPRArg = ONLY_USED | ONLY_GPR | ONLY_ARG,
83     // Only zeros call-used GPRs used in the fn.
84     UsedGPR = ONLY_USED | ONLY_GPR,
85     // Only zeros call-used regs used in the fn and pass args.
86     UsedArg = ONLY_USED | ONLY_ARG,
87     // Only zeros call-used regs used in the fn.
88     Used = ONLY_USED,
89     // Zeros all call-used GPRs that pass args.
90     AllGPRArg = ONLY_GPR | ONLY_ARG,
91     // Zeros all call-used GPRs.
92     AllGPR = ONLY_GPR,
93     // Zeros all call-used regs that pass args.
94     AllArg = ONLY_ARG,
95     // Zeros all call-used regs.
96     All = 0,
97   };
98   } // namespace ZeroCallUsedRegs
99 
100   enum class UWTableKind {
101     None = 0,  ///< No unwind table requested
102     Sync = 1,  ///< "Synchronous" unwind tables
103     Async = 2, ///< "Asynchronous" unwind tables (instr precise)
104     Default = 2,
105   };
106 
107   enum class FunctionReturnThunksKind : unsigned int {
108     Keep = 0,    ///< No function return thunk.
109     Extern = 1,  ///< Replace returns with jump to thunk, don't emit thunk.
110     Invalid = 2, ///< Not used.
111   };
112 
113   } // namespace llvm
114 
115 #endif
116