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1 /* ===-- assembly.h - compiler-rt assembler support macros -----------------===
2  *
3  *                     The LLVM Compiler Infrastructure
4  *
5  * This file is dual licensed under the MIT and the University of Illinois Open
6  * Source Licenses. See LICENSE.TXT for details.
7  *
8  * ===----------------------------------------------------------------------===
9  *
10  * This file defines macros for use in compiler-rt assembler source.
11  * This file is not part of the interface of this library.
12  *
13  * ===----------------------------------------------------------------------===
14  */
15 
16 #ifndef COMPILERRT_ASSEMBLY_H
17 #define COMPILERRT_ASSEMBLY_H
18 
19 #if defined(__POWERPC__) || defined(__powerpc__) || defined(__ppc__)
20 #define SEPARATOR @
21 #else
22 #define SEPARATOR ;
23 #endif
24 
25 #if defined(__APPLE__)
26 #define HIDDEN(name) .private_extern name
27 #define LOCAL_LABEL(name) L_##name
28 // tell linker it can break up file at label boundaries
29 #define FILE_LEVEL_DIRECTIVE .subsections_via_symbols
30 #define SYMBOL_IS_FUNC(name)
31 #define CONST_SECTION .const
32 
33 #define NO_EXEC_STACK_DIRECTIVE
34 
35 #elif defined(__ELF__)
36 
37 #define HIDDEN(name) .hidden name
38 #define LOCAL_LABEL(name) .L_##name
39 #define FILE_LEVEL_DIRECTIVE
40 #if defined(__arm__)
41 #define SYMBOL_IS_FUNC(name) .type name,%function
42 #else
43 #define SYMBOL_IS_FUNC(name) .type name,@function
44 #endif
45 #define CONST_SECTION .section .rodata
46 
47 #if defined(__GNU__) || defined(__ANDROID__) || defined(__FreeBSD__)
48 #define NO_EXEC_STACK_DIRECTIVE .section .note.GNU-stack,"",%progbits
49 #else
50 #define NO_EXEC_STACK_DIRECTIVE
51 #endif
52 
53 #else // !__APPLE__ && !__ELF__
54 
55 #define HIDDEN(name)
56 #define LOCAL_LABEL(name) .L ## name
57 #define FILE_LEVEL_DIRECTIVE
58 #define SYMBOL_IS_FUNC(name)                                                   \
59   .def name SEPARATOR                                                          \
60     .scl 2 SEPARATOR                                                           \
61     .type 32 SEPARATOR                                                         \
62   .endef
63 #define CONST_SECTION .section .rdata,"rd"
64 
65 #define NO_EXEC_STACK_DIRECTIVE
66 
67 #endif
68 
69 #if defined(__arm__)
70 #if defined(__ARM_ARCH_4T__) || __ARM_ARCH >= 5
71 #define ARM_HAS_BX
72 #endif
73 #if !defined(__ARM_FEATURE_CLZ) && __ARM_ARCH_ISA_THUMB != 1 &&                \
74     (__ARM_ARCH >= 6 || (__ARM_ARCH == 5 && !defined(__ARM_ARCH_5__)))
75 #define __ARM_FEATURE_CLZ
76 #endif
77 
78 #ifdef ARM_HAS_BX
79 #define JMP(r) bx r
80 #define JMPc(r, c) bx##c r
81 #else
82 #define JMP(r) mov pc, r
83 #define JMPc(r, c) mov##c pc, r
84 #endif
85 
86 // pop {pc} can't switch Thumb mode on ARMv4T
87 #if __ARM_ARCH >= 5
88 #define POP_PC() pop {pc}
89 #else
90 #define POP_PC()                                                               \
91   pop {ip};                                                                    \
92   JMP(ip)
93 #endif
94 
95 #if __ARM_ARCH_ISA_THUMB == 2
96 #define IT(cond)  it cond
97 #define ITT(cond) itt cond
98 #else
99 #define IT(cond)
100 #define ITT(cond)
101 #endif
102 
103 #if __ARM_ARCH_ISA_THUMB == 2
104 #define WIDE(op) op.w
105 #else
106 #define WIDE(op) op
107 #endif
108 #endif
109 
110 #define GLUE2(a, b) a##b
111 #define GLUE(a, b) GLUE2(a, b)
112 #define SYMBOL_NAME(name) GLUE(__USER_LABEL_PREFIX__, name)
113 
114 #ifdef VISIBILITY_HIDDEN
115 #define DECLARE_SYMBOL_VISIBILITY(name)                                        \
116   HIDDEN(SYMBOL_NAME(name)) SEPARATOR
117 #else
118 #define DECLARE_SYMBOL_VISIBILITY(name)
119 #endif
120 
121 #define DEFINE_COMPILERRT_FUNCTION(name)                                       \
122   FILE_LEVEL_DIRECTIVE SEPARATOR                                               \
123   .globl SYMBOL_NAME(name) SEPARATOR                                           \
124   SYMBOL_IS_FUNC(SYMBOL_NAME(name)) SEPARATOR                                  \
125   DECLARE_SYMBOL_VISIBILITY(name)                                              \
126   SYMBOL_NAME(name):
127 
128 #define DEFINE_COMPILERRT_THUMB_FUNCTION(name)                                 \
129   FILE_LEVEL_DIRECTIVE SEPARATOR                                               \
130   .globl SYMBOL_NAME(name) SEPARATOR                                           \
131   SYMBOL_IS_FUNC(SYMBOL_NAME(name)) SEPARATOR                                  \
132   DECLARE_SYMBOL_VISIBILITY(name) SEPARATOR                                    \
133   .thumb_func SEPARATOR                                                        \
134   SYMBOL_NAME(name):
135 
136 #define DEFINE_COMPILERRT_PRIVATE_FUNCTION(name)                               \
137   FILE_LEVEL_DIRECTIVE SEPARATOR                                               \
138   .globl SYMBOL_NAME(name) SEPARATOR                                           \
139   SYMBOL_IS_FUNC(SYMBOL_NAME(name)) SEPARATOR                                  \
140   HIDDEN(SYMBOL_NAME(name)) SEPARATOR                                          \
141   SYMBOL_NAME(name):
142 
143 #define DEFINE_COMPILERRT_PRIVATE_FUNCTION_UNMANGLED(name)                     \
144   .globl name SEPARATOR                                                        \
145   SYMBOL_IS_FUNC(name) SEPARATOR                                               \
146   HIDDEN(name) SEPARATOR                                                       \
147   name:
148 
149 #define DEFINE_COMPILERRT_FUNCTION_ALIAS(name, target)                         \
150   .globl SYMBOL_NAME(name) SEPARATOR                                           \
151   SYMBOL_IS_FUNC(SYMBOL_NAME(name)) SEPARATOR                                  \
152   DECLARE_SYMBOL_VISIBILITY(SYMBOL_NAME(name)) SEPARATOR                       \
153   .set SYMBOL_NAME(name), SYMBOL_NAME(target) SEPARATOR
154 
155 #if defined(__ARM_EABI__)
156 #define DEFINE_AEABI_FUNCTION_ALIAS(aeabi_name, name)                          \
157   DEFINE_COMPILERRT_FUNCTION_ALIAS(aeabi_name, name)
158 #else
159 #define DEFINE_AEABI_FUNCTION_ALIAS(aeabi_name, name)
160 #endif
161 
162 #ifdef __ELF__
163 #define END_COMPILERRT_FUNCTION(name)                                          \
164   .size SYMBOL_NAME(name), . - SYMBOL_NAME(name)
165 #else
166 #define END_COMPILERRT_FUNCTION(name)
167 #endif
168 
169 #endif /* COMPILERRT_ASSEMBLY_H */
170