xref: /freebsd/contrib/llvm-project/compiler-rt/lib/builtins/assembly.h (revision 6966ac055c3b7a39266fb982493330df7a097997)
1 //===-- assembly.h - compiler-rt assembler support macros -----------------===//
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 defines macros for use in compiler-rt assembler source.
10 // This file is not part of the interface of this library.
11 //
12 //===----------------------------------------------------------------------===//
13 
14 #ifndef COMPILERRT_ASSEMBLY_H
15 #define COMPILERRT_ASSEMBLY_H
16 
17 #if defined(__POWERPC__) || defined(__powerpc__) || defined(__ppc__)
18 #define SEPARATOR @
19 #else
20 #define SEPARATOR ;
21 #endif
22 
23 #if defined(__APPLE__)
24 #define HIDDEN(name) .private_extern name
25 #define LOCAL_LABEL(name) L_##name
26 // tell linker it can break up file at label boundaries
27 #define FILE_LEVEL_DIRECTIVE .subsections_via_symbols
28 #define SYMBOL_IS_FUNC(name)
29 #define CONST_SECTION .const
30 
31 #define NO_EXEC_STACK_DIRECTIVE
32 
33 #elif defined(__ELF__)
34 
35 #define HIDDEN(name) .hidden name
36 #define LOCAL_LABEL(name) .L_##name
37 #define FILE_LEVEL_DIRECTIVE
38 #if defined(__arm__)
39 #define SYMBOL_IS_FUNC(name) .type name,%function
40 #else
41 #define SYMBOL_IS_FUNC(name) .type name,@function
42 #endif
43 #define CONST_SECTION .section .rodata
44 
45 #if defined(__GNU__) || defined(__FreeBSD__) || defined(__Fuchsia__) || \
46     defined(__linux__)
47 #define NO_EXEC_STACK_DIRECTIVE .section .note.GNU-stack,"",%progbits
48 #else
49 #define NO_EXEC_STACK_DIRECTIVE
50 #endif
51 
52 #else // !__APPLE__ && !__ELF__
53 
54 #define HIDDEN(name)
55 #define LOCAL_LABEL(name) .L ## name
56 #define FILE_LEVEL_DIRECTIVE
57 #define SYMBOL_IS_FUNC(name)                                                   \
58   .def name SEPARATOR                                                          \
59     .scl 2 SEPARATOR                                                           \
60     .type 32 SEPARATOR                                                         \
61   .endef
62 #define CONST_SECTION .section .rdata,"rd"
63 
64 #define NO_EXEC_STACK_DIRECTIVE
65 
66 #endif
67 
68 #if defined(__arm__)
69 
70 // Determine actual [ARM][THUMB[1][2]] ISA using compiler predefined macros:
71 // - for '-mthumb -march=armv6' compiler defines '__thumb__'
72 // - for '-mthumb -march=armv7' compiler defines '__thumb__' and '__thumb2__'
73 #if defined(__thumb2__) || defined(__thumb__)
74 #define DEFINE_CODE_STATE .thumb SEPARATOR
75 #define DECLARE_FUNC_ENCODING    .thumb_func SEPARATOR
76 #if defined(__thumb2__)
77 #define USE_THUMB_2
78 #define IT(cond)  it cond
79 #define ITT(cond) itt cond
80 #define ITE(cond) ite cond
81 #else
82 #define USE_THUMB_1
83 #define IT(cond)
84 #define ITT(cond)
85 #define ITE(cond)
86 #endif // defined(__thumb__2)
87 #else // !defined(__thumb2__) && !defined(__thumb__)
88 #define DEFINE_CODE_STATE .arm SEPARATOR
89 #define DECLARE_FUNC_ENCODING
90 #define IT(cond)
91 #define ITT(cond)
92 #define ITE(cond)
93 #endif
94 
95 #if defined(USE_THUMB_1) && defined(USE_THUMB_2)
96 #error "USE_THUMB_1 and USE_THUMB_2 can't be defined together."
97 #endif
98 
99 #if defined(__ARM_ARCH_4T__) || __ARM_ARCH >= 5
100 #define ARM_HAS_BX
101 #endif
102 #if !defined(__ARM_FEATURE_CLZ) && !defined(USE_THUMB_1) &&  \
103     (__ARM_ARCH >= 6 || (__ARM_ARCH == 5 && !defined(__ARM_ARCH_5__)))
104 #define __ARM_FEATURE_CLZ
105 #endif
106 
107 #ifdef ARM_HAS_BX
108 #define JMP(r) bx r
109 #define JMPc(r, c) bx##c r
110 #else
111 #define JMP(r) mov pc, r
112 #define JMPc(r, c) mov##c pc, r
113 #endif
114 
115 // pop {pc} can't switch Thumb mode on ARMv4T
116 #if __ARM_ARCH >= 5
117 #define POP_PC() pop {pc}
118 #else
119 #define POP_PC()                                                               \
120   pop {ip};                                                                    \
121   JMP(ip)
122 #endif
123 
124 #if defined(USE_THUMB_2)
125 #define WIDE(op) op.w
126 #else
127 #define WIDE(op) op
128 #endif
129 #else // !defined(__arm)
130 #define DECLARE_FUNC_ENCODING
131 #define DEFINE_CODE_STATE
132 #endif
133 
134 #define GLUE2(a, b) a##b
135 #define GLUE(a, b) GLUE2(a, b)
136 #define SYMBOL_NAME(name) GLUE(__USER_LABEL_PREFIX__, name)
137 
138 #ifdef VISIBILITY_HIDDEN
139 #define DECLARE_SYMBOL_VISIBILITY(name)                                        \
140   HIDDEN(SYMBOL_NAME(name)) SEPARATOR
141 #else
142 #define DECLARE_SYMBOL_VISIBILITY(name)
143 #endif
144 
145 #define DEFINE_COMPILERRT_FUNCTION(name)                                       \
146   DEFINE_CODE_STATE                                                            \
147   FILE_LEVEL_DIRECTIVE SEPARATOR                                               \
148   .globl SYMBOL_NAME(name) SEPARATOR                                           \
149   SYMBOL_IS_FUNC(SYMBOL_NAME(name)) SEPARATOR                                  \
150   DECLARE_SYMBOL_VISIBILITY(name)                                              \
151   DECLARE_FUNC_ENCODING                                                        \
152   SYMBOL_NAME(name):
153 
154 #define DEFINE_COMPILERRT_THUMB_FUNCTION(name)                                 \
155   DEFINE_CODE_STATE                                                            \
156   FILE_LEVEL_DIRECTIVE SEPARATOR                                               \
157   .globl SYMBOL_NAME(name) SEPARATOR                                           \
158   SYMBOL_IS_FUNC(SYMBOL_NAME(name)) SEPARATOR                                  \
159   DECLARE_SYMBOL_VISIBILITY(name) SEPARATOR                                    \
160   .thumb_func SEPARATOR                                                        \
161   SYMBOL_NAME(name):
162 
163 #define DEFINE_COMPILERRT_PRIVATE_FUNCTION(name)                               \
164   DEFINE_CODE_STATE                                                            \
165   FILE_LEVEL_DIRECTIVE SEPARATOR                                               \
166   .globl SYMBOL_NAME(name) SEPARATOR                                           \
167   SYMBOL_IS_FUNC(SYMBOL_NAME(name)) SEPARATOR                                  \
168   HIDDEN(SYMBOL_NAME(name)) SEPARATOR                                          \
169   DECLARE_FUNC_ENCODING                                                        \
170   SYMBOL_NAME(name):
171 
172 #define DEFINE_COMPILERRT_PRIVATE_FUNCTION_UNMANGLED(name)                     \
173   DEFINE_CODE_STATE                                                            \
174   .globl name SEPARATOR                                                        \
175   SYMBOL_IS_FUNC(name) SEPARATOR                                               \
176   HIDDEN(name) SEPARATOR                                                       \
177   DECLARE_FUNC_ENCODING                                                        \
178   name:
179 
180 #define DEFINE_COMPILERRT_FUNCTION_ALIAS(name, target)                         \
181   .globl SYMBOL_NAME(name) SEPARATOR                                           \
182   SYMBOL_IS_FUNC(SYMBOL_NAME(name)) SEPARATOR                                  \
183   DECLARE_SYMBOL_VISIBILITY(SYMBOL_NAME(name)) SEPARATOR                       \
184   .set SYMBOL_NAME(name), SYMBOL_NAME(target) SEPARATOR
185 
186 #if defined(__ARM_EABI__)
187 #define DEFINE_AEABI_FUNCTION_ALIAS(aeabi_name, name)                          \
188   DEFINE_COMPILERRT_FUNCTION_ALIAS(aeabi_name, name)
189 #else
190 #define DEFINE_AEABI_FUNCTION_ALIAS(aeabi_name, name)
191 #endif
192 
193 #ifdef __ELF__
194 #define END_COMPILERRT_FUNCTION(name)                                          \
195   .size SYMBOL_NAME(name), . - SYMBOL_NAME(name)
196 #else
197 #define END_COMPILERRT_FUNCTION(name)
198 #endif
199 
200 #endif // COMPILERRT_ASSEMBLY_H
201