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(__FreeBSD__) || defined(__Fuchsia__) || \
48     defined(__linux__)
49 #define NO_EXEC_STACK_DIRECTIVE .section .note.GNU-stack,"",%progbits
50 #else
51 #define NO_EXEC_STACK_DIRECTIVE
52 #endif
53 
54 #else // !__APPLE__ && !__ELF__
55 
56 #define HIDDEN(name)
57 #define LOCAL_LABEL(name) .L ## name
58 #define FILE_LEVEL_DIRECTIVE
59 #define SYMBOL_IS_FUNC(name)                                                   \
60   .def name SEPARATOR                                                          \
61     .scl 2 SEPARATOR                                                           \
62     .type 32 SEPARATOR                                                         \
63   .endef
64 #define CONST_SECTION .section .rdata,"rd"
65 
66 #define NO_EXEC_STACK_DIRECTIVE
67 
68 #endif
69 
70 #if defined(__arm__)
71 
72 /*
73  * Determine actual [ARM][THUMB[1][2]] ISA using compiler predefined macros:
74  * - for '-mthumb -march=armv6' compiler defines '__thumb__'
75  * - for '-mthumb -march=armv7' compiler defines '__thumb__' and '__thumb2__'
76  */
77 #if defined(__thumb2__) || defined(__thumb__)
78 #define DEFINE_CODE_STATE .thumb SEPARATOR
79 #define DECLARE_FUNC_ENCODING    .thumb_func SEPARATOR
80 #if defined(__thumb2__)
81 #define USE_THUMB_2
82 #define IT(cond)  it cond
83 #define ITT(cond) itt cond
84 #define ITE(cond) ite cond
85 #else
86 #define USE_THUMB_1
87 #define IT(cond)
88 #define ITT(cond)
89 #define ITE(cond)
90 #endif // defined(__thumb__2)
91 #else // !defined(__thumb2__) && !defined(__thumb__)
92 #define DEFINE_CODE_STATE .arm SEPARATOR
93 #define DECLARE_FUNC_ENCODING
94 #define IT(cond)
95 #define ITT(cond)
96 #define ITE(cond)
97 #endif
98 
99 #if defined(USE_THUMB_1) && defined(USE_THUMB_2)
100 #error "USE_THUMB_1 and USE_THUMB_2 can't be defined together."
101 #endif
102 
103 #if defined(__ARM_ARCH_4T__) || __ARM_ARCH >= 5
104 #define ARM_HAS_BX
105 #endif
106 #if !defined(__ARM_FEATURE_CLZ) && !defined(USE_THUMB_1) &&  \
107     (__ARM_ARCH >= 6 || (__ARM_ARCH == 5 && !defined(__ARM_ARCH_5__)))
108 #define __ARM_FEATURE_CLZ
109 #endif
110 
111 #ifdef ARM_HAS_BX
112 #define JMP(r) bx r
113 #define JMPc(r, c) bx##c r
114 #else
115 #define JMP(r) mov pc, r
116 #define JMPc(r, c) mov##c pc, r
117 #endif
118 
119 // pop {pc} can't switch Thumb mode on ARMv4T
120 #if __ARM_ARCH >= 5
121 #define POP_PC() pop {pc}
122 #else
123 #define POP_PC()                                                               \
124   pop {ip};                                                                    \
125   JMP(ip)
126 #endif
127 
128 #if defined(USE_THUMB_2)
129 #define WIDE(op) op.w
130 #else
131 #define WIDE(op) op
132 #endif
133 #else // !defined(__arm)
134 #define DECLARE_FUNC_ENCODING
135 #define DEFINE_CODE_STATE
136 #endif
137 
138 #define GLUE2(a, b) a##b
139 #define GLUE(a, b) GLUE2(a, b)
140 #define SYMBOL_NAME(name) GLUE(__USER_LABEL_PREFIX__, name)
141 
142 #ifdef VISIBILITY_HIDDEN
143 #define DECLARE_SYMBOL_VISIBILITY(name)                                        \
144   HIDDEN(SYMBOL_NAME(name)) SEPARATOR
145 #else
146 #define DECLARE_SYMBOL_VISIBILITY(name)
147 #endif
148 
149 #define DEFINE_COMPILERRT_FUNCTION(name)                                       \
150   DEFINE_CODE_STATE                                                            \
151   FILE_LEVEL_DIRECTIVE SEPARATOR                                               \
152   .globl SYMBOL_NAME(name) SEPARATOR                                           \
153   SYMBOL_IS_FUNC(SYMBOL_NAME(name)) SEPARATOR                                  \
154   DECLARE_SYMBOL_VISIBILITY(name)                                              \
155   DECLARE_FUNC_ENCODING                                                        \
156   SYMBOL_NAME(name):
157 
158 #define DEFINE_COMPILERRT_THUMB_FUNCTION(name)                                 \
159   DEFINE_CODE_STATE                                                            \
160   FILE_LEVEL_DIRECTIVE SEPARATOR                                               \
161   .globl SYMBOL_NAME(name) SEPARATOR                                           \
162   SYMBOL_IS_FUNC(SYMBOL_NAME(name)) SEPARATOR                                  \
163   DECLARE_SYMBOL_VISIBILITY(name) SEPARATOR                                    \
164   .thumb_func SEPARATOR                                                        \
165   SYMBOL_NAME(name):
166 
167 #define DEFINE_COMPILERRT_PRIVATE_FUNCTION(name)                               \
168   DEFINE_CODE_STATE                                                            \
169   FILE_LEVEL_DIRECTIVE SEPARATOR                                               \
170   .globl SYMBOL_NAME(name) SEPARATOR                                           \
171   SYMBOL_IS_FUNC(SYMBOL_NAME(name)) SEPARATOR                                  \
172   HIDDEN(SYMBOL_NAME(name)) SEPARATOR                                          \
173   DECLARE_FUNC_ENCODING                                                        \
174   SYMBOL_NAME(name):
175 
176 #define DEFINE_COMPILERRT_PRIVATE_FUNCTION_UNMANGLED(name)                     \
177   DEFINE_CODE_STATE                                                            \
178   .globl name SEPARATOR                                                        \
179   SYMBOL_IS_FUNC(name) SEPARATOR                                               \
180   HIDDEN(name) SEPARATOR                                                       \
181   DECLARE_FUNC_ENCODING                                                        \
182   name:
183 
184 #define DEFINE_COMPILERRT_FUNCTION_ALIAS(name, target)                         \
185   .globl SYMBOL_NAME(name) SEPARATOR                                           \
186   SYMBOL_IS_FUNC(SYMBOL_NAME(name)) SEPARATOR                                  \
187   DECLARE_SYMBOL_VISIBILITY(SYMBOL_NAME(name)) SEPARATOR                       \
188   .set SYMBOL_NAME(name), SYMBOL_NAME(target) SEPARATOR
189 
190 #if defined(__ARM_EABI__)
191 #define DEFINE_AEABI_FUNCTION_ALIAS(aeabi_name, name)                          \
192   DEFINE_COMPILERRT_FUNCTION_ALIAS(aeabi_name, name)
193 #else
194 #define DEFINE_AEABI_FUNCTION_ALIAS(aeabi_name, name)
195 #endif
196 
197 #ifdef __ELF__
198 #define END_COMPILERRT_FUNCTION(name)                                          \
199   .size SYMBOL_NAME(name), . - SYMBOL_NAME(name)
200 #else
201 #define END_COMPILERRT_FUNCTION(name)
202 #endif
203 
204 #endif /* COMPILERRT_ASSEMBLY_H */
205