1 /* Target definitions for x86 running Darwin.
2    Copyright (C) 2001-2022 Free Software Foundation, Inc.
3    Contributed by Apple Computer Inc.
4 
5 This file is part of GCC.
6 
7 GCC is free software; you can redistribute it and/or modify
8 it under the terms of the GNU General Public License as published by
9 the Free Software Foundation; either version 3, or (at your option)
10 any later version.
11 
12 GCC is distributed in the hope that it will be useful,
13 but WITHOUT ANY WARRANTY; without even the implied warranty of
14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
15 GNU General Public License for more details.
16 
17 You should have received a copy of the GNU General Public License
18 along with GCC; see the file COPYING3.  If not see
19 <http://www.gnu.org/licenses/>.  */
20 
21 /* Enable Mach-O bits in generic x86 code.  */
22 #undef TARGET_MACHO
23 #define TARGET_MACHO 1
24 
25 #undef DARWIN_X86
26 #define DARWIN_X86 1
27 
28 /* Size of the Obj-C jump buffer.  */
29 #define OBJC_JBLEN ((TARGET_64BIT) ? ((9 * 2) + 3 + 16) : (18))
30 
31 #undef TARGET_FPMATH_DEFAULT
32 #define TARGET_FPMATH_DEFAULT (TARGET_SSE ? FPMATH_SSE : FPMATH_387)
33 #undef TARGET_FPMATH_DEFAULT_P
34 #define TARGET_FPMATH_DEFAULT_P(x) \
35   (TARGET_SSE_P(x) ? FPMATH_SSE : FPMATH_387)
36 
37 #define TARGET_OS_CPP_BUILTINS()                \
38   do {                                                      \
39     builtin_define ("__LITTLE_ENDIAN__");         \
40     darwin_cpp_builtins (pfile);                  \
41   } while (0)
42 
43 #undef PTRDIFF_TYPE
44 #define PTRDIFF_TYPE (TARGET_64BIT ? "long int" : "int")
45 
46 #undef WCHAR_TYPE
47 #define WCHAR_TYPE "int"
48 
49 #undef WCHAR_TYPE_SIZE
50 #define WCHAR_TYPE_SIZE 32
51 
52 /* Generate pic symbol indirection stubs if this is true.  */
53 #undef TARGET_MACHO_SYMBOL_STUBS
54 #define TARGET_MACHO_SYMBOL_STUBS (darwin_symbol_stubs)
55 
56 /* For compatibility with OSX system tools, use the new style of pic stub
57    if this is set (default).  */
58 #undef  MACHOPIC_ATT_STUB
59 #define MACHOPIC_ATT_STUB (darwin_macho_att_stub)
60 
61 #undef MAX_BITS_PER_WORD
62 #define MAX_BITS_PER_WORD 64
63 
64 #undef FORCE_PREFERRED_STACK_BOUNDARY_IN_MAIN
65 #define FORCE_PREFERRED_STACK_BOUNDARY_IN_MAIN (0)
66 
67 #undef TARGET_KEEPS_VECTOR_ALIGNED_STACK
68 #define TARGET_KEEPS_VECTOR_ALIGNED_STACK 1
69 
70 /* On Darwin, the stack is 128-bit aligned at the point of every call.
71    Failure to ensure this will lead to a crash in the system libraries
72    or dynamic loader.  */
73 
74 #undef MAIN_STACK_BOUNDARY
75 #define MAIN_STACK_BOUNDARY 128
76 
77 /* Since we'll never want a stack boundary less aligned than 128 bits
78    we need the extra work here otherwise bits of gcc get very grumpy
79    when we ask for lower alignment.  We could just reject values less
80    than 128 bits for Darwin, but it's easier to up the alignment if
81    it's below the minimum.  */
82 #undef PREFERRED_STACK_BOUNDARY
83 #define PREFERRED_STACK_BOUNDARY \
84   MAX (128, ix86_preferred_stack_boundary)
85 
86 /* We want -fPIC by default, unless we're using -static to compile for
87    the kernel or some such.  */
88 
89 #undef CC1_SPEC
90 #define CC1_SPEC "%(cc1_cpu) \
91   %{!mkernel:%{!static:%{!mdynamic-no-pic:-fPIC}}} \
92   %{g: %{!fno-eliminate-unused-debug-symbols: -feliminate-unused-debug-symbols }} \
93   %{mx32:%eDarwin is not an mx32 platform} \
94   %{mfentry*:%eDarwin does not support -mfentry or associated options}" \
95   DARWIN_CC1_SPEC
96 
97 /* This is a workaround for a tool bug: see PR100340.  */
98 
99 #ifdef HAVE_AS_MLLVM_X86_PAD_FOR_ALIGN
100 #define EXTRA_ASM_OPTS " -mllvm -x86-pad-for-align=false "
101 #else
102 #define EXTRA_ASM_OPTS ""
103 #endif
104 
105 #undef ASM_SPEC
106 #define ASM_SPEC \
107 "%{static} -arch %(darwin_arch) " \
108  ASM_OPTIONS ASM_MMACOSX_VERSION_MIN_SPEC EXTRA_ASM_OPTS \
109 "%{!force_cpusubtype_ALL:-force_cpusubtype_ALL} "
110 
111 #undef ENDFILE_SPEC
112 #define ENDFILE_SPEC \
113   "%{mdaz-ftz:crtfastmath.o%s;Ofast|ffast-math|funsafe-math-optimizations:%{!mno-daz-ftz:crtfastmath.o%s}} \
114    %{mpc32:crtprec32.o%s} \
115    %{mpc64:crtprec64.o%s} \
116    %{mpc80:crtprec80.o%s}" TM_DESTRUCTOR
117 
118 #ifndef DARWIN_ARCH_SPEC
119 /* We default to x86_64 for single-arch builds, bi-arch overrides.  */
120 #define DARWIN_ARCH_SPEC "x86_64"
121 #define DARWIN_SUBARCH_SPEC DARWIN_ARCH_SPEC
122 #endif
123 
124 #undef SUBTARGET_EXTRA_SPECS
125 #define SUBTARGET_EXTRA_SPECS                                   \
126   DARWIN_EXTRA_SPECS                                            \
127   { "darwin_arch", DARWIN_ARCH_SPEC },                                \
128   { "darwin_crt2", "" },                                        \
129   { "darwin_subarch", DARWIN_ARCH_SPEC },
130 
131 /* The Darwin assembler mostly follows AT&T syntax.  */
132 #undef ASSEMBLER_DIALECT
133 #define ASSEMBLER_DIALECT ASM_ATT
134 
135 /* Define macro used to output shift-double opcodes when the shift
136    count is in %cl.  Some assemblers require %cl as an argument;
137    some don't.  This macro controls what to do: by default, don't
138    print %cl.  */
139 
140 #define SHIFT_DOUBLE_OMITS_COUNT 0
141 
142 #undef TARGET_ASM_FILE_END
143 #define TARGET_ASM_FILE_END darwin_file_end
144 
145 /* Define the syntax of pseudo-ops, labels and comments.  */
146 
147 /* String containing the assembler's comment-starter.  */
148 
149 #define ASM_COMMENT_START "#"
150 
151 /* By default, target has a 80387, uses IEEE compatible arithmetic,
152    and returns float values in the 387.  */
153 
154 #undef TARGET_SUBTARGET_DEFAULT
155 #define TARGET_SUBTARGET_DEFAULT \
156   (MASK_80387 | MASK_IEEE_FP | MASK_FLOAT_RETURNS | MASK_128BIT_LONG_DOUBLE)
157 
158 /* For darwin we want to target specific processor features as a minimum,
159    but these unfortunately don't correspond to a specific processor.  */
160 #undef TARGET_SUBTARGET32_ISA_DEFAULT
161 #define TARGET_SUBTARGET32_ISA_DEFAULT                      \
162   (OPTION_MASK_ISA_MMX | OPTION_MASK_ISA_SSE                \
163    | OPTION_MASK_ISA_SSE2 | OPTION_MASK_ISA_SSE3)
164 
165 #undef TARGET_SUBTARGET64_ISA_DEFAULT
166 #define TARGET_SUBTARGET64_ISA_DEFAULT TARGET_SUBTARGET32_ISA_DEFAULT
167 
168 #undef GOT_SYMBOL_NAME
169 #define GOT_SYMBOL_NAME MACHOPIC_FUNCTION_BASE_NAME
170 
171 /* Define the syntax of pseudo-ops, labels and comments.  */
172 
173 #define LPREFIX "L"
174 
175 /* Assembler pseudos to introduce constants of various size.  */
176 
177 #define ASM_BYTE "\t.byte\t"
178 #define ASM_SHORT "\t.word\t"
179 #define ASM_LONG "\t.long\t"
180 #define ASM_QUAD "\t.quad\t"
181 
182 #define SUBTARGET_ENCODE_SECTION_INFO  darwin_encode_section_info
183 
184 #undef ASM_OUTPUT_ALIGN
185 #define ASM_OUTPUT_ALIGN(FILE,LOG)                                       \
186   do {                                                                             \
187     if ((LOG) != 0)                                                      \
188       {                                                                            \
189           if (in_section == text_section)                                          \
190             fprintf (FILE, "\t%s %d,0x90\n", ALIGN_ASM_OP, (LOG));   \
191           else                                                                     \
192             fprintf (FILE, "\t%s %d\n", ALIGN_ASM_OP, (LOG));            \
193       }                                                                            \
194   } while (0)
195 
196 /* Darwin x86 assemblers support the .ident directive.  */
197 
198 #undef TARGET_ASM_OUTPUT_IDENT
199 #define TARGET_ASM_OUTPUT_IDENT default_asm_output_ident_directive
200 
201 /* We always want jump tables in the text section:
202    * for PIC code, we need the subtracted symbol to be defined at
203      assembly-time.
204    * for mdynamic-no-pic, we cannot support jump tables in the .const
205      section for weak functions, this looks to ld64 like direct access
206      to the weak symbol from an anonymous atom.  */
207 
208 #undef JUMP_TABLES_IN_TEXT_SECTION
209 #define JUMP_TABLES_IN_TEXT_SECTION 1
210 
211 /* Darwin profiling -- call mcount.
212    If we need a stub, then we unconditionally mark it as used.  */
213 #undef FUNCTION_PROFILER
214 #define FUNCTION_PROFILER(FILE, LABELNO)                                        \
215   do {                                                                                    \
216     if (TARGET_MACHO_SYMBOL_STUBS                                               \
217           && MACHOPIC_INDIRECT && !TARGET_64BIT)                                \
218       {                                                                                   \
219           const char *name = machopic_mcount_stub_name ();            \
220           fprintf (FILE, "\tcall %s\n", name+1);  /*  skip '&'  */    \
221       }                                                                                   \
222     else fprintf (FILE, "\tcall mcount\n");                                     \
223   } while (0)
224 
225 #define C_COMMON_OVERRIDE_OPTIONS                                               \
226   do {                                                                                    \
227     SUBTARGET_C_COMMON_OVERRIDE_OPTIONS;                                        \
228   } while (0)
229 
230 #undef SUBTARGET_OVERRIDE_OPTIONS
231 #define SUBTARGET_OVERRIDE_OPTIONS                                              \
232   do {                                                                                    \
233     if (TARGET_64BIT && MACHO_DYNAMIC_NO_PIC_P)                                 \
234       target_flags &= ~MASK_MACHO_DYNAMIC_NO_PIC;                     \
235   } while (0)
236 
237 /* Darwin uses the standard DWARF register numbers but the default
238    register numbers for STABS.  Fortunately for 64-bit code the
239    default and the standard are the same.  */
240 #undef DBX_REGISTER_NUMBER
241 #define DBX_REGISTER_NUMBER(n)                                                  \
242   (TARGET_64BIT ? dbx64_register_map[n]                               \
243    : dwarf_debuginfo_p () ? svr4_dbx_register_map[n]                  \
244    : dbx_register_map[n])
245 
246 /* Unfortunately, the 32-bit EH information also doesn't use the standard
247    DWARF register numbers.  */
248 #define DWARF2_FRAME_REG_OUT(n, for_eh)                                         \
249   (! (for_eh) || !dwarf_debuginfo_p () || TARGET_64BIT ? (n)          \
250    : (n) == 5 ? 4                                                               \
251    : (n) == 4 ? 5                                                               \
252    : (n) >= 11 && (n) <= 18 ? (n) + 1                                           \
253    : (n))
254 
255 #undef REGISTER_SUBTARGET_PRAGMAS
256 #define REGISTER_SUBTARGET_PRAGMAS() DARWIN_REGISTER_TARGET_PRAGMAS()
257 
258 #undef TARGET_SET_DEFAULT_TYPE_ATTRIBUTES
259 #define TARGET_SET_DEFAULT_TYPE_ATTRIBUTES darwin_set_default_type_attributes
260 
261 /* For 64-bit, we need to add 4 because @GOTPCREL is relative to the
262    end of the instruction, but without the 4 we'd only have the right
263    address for the start of the instruction.  */
264 #undef ASM_MAYBE_OUTPUT_ENCODED_ADDR_RTX
265 #define ASM_MAYBE_OUTPUT_ENCODED_ADDR_RTX(FILE, ENCODING, SIZE, ADDR, DONE) \
266   if (TARGET_64BIT)                                                             \
267     {                                                                                     \
268       if ((SIZE) == 4 && ((ENCODING) & 0x70) == DW_EH_PE_pcrel)                 \
269           {                                                                               \
270             fputs (ASM_LONG, FILE);                                             \
271             assemble_name (FILE, XSTR (ADDR, 0));                               \
272             fputs ("+4@GOTPCREL", FILE);                                                  \
273             goto DONE;                                                                    \
274           }                                                                               \
275     }                                                                                     \
276   else                                                                                    \
277     {                                                                                     \
278       if (ENCODING == ASM_PREFERRED_EH_DATA_FORMAT (2, 1))            \
279         {                                                                       \
280           darwin_non_lazy_pcrel (FILE, ADDR);                                   \
281           goto DONE;                                                                      \
282         }                                                                       \
283     }
284 
285 /* First available SYMBOL flag bit for use by subtargets.  */
286 #define SYMBOL_FLAG_SUBT_DEP (SYMBOL_FLAG_MACH_DEP << 5)
287 
288 #undef MACHOPIC_NL_SYMBOL_PTR_SECTION
289 #define MACHOPIC_NL_SYMBOL_PTR_SECTION \
290                     ".section __IMPORT,__pointers,non_lazy_symbol_pointers"
291 
292 #define SUBTARGET32_DEFAULT_CPU "i686"
293 
294 #undef  SUBTARGET_INIT_BUILTINS
295 #define SUBTARGET_INIT_BUILTINS                                                           \
296   do {                                                                                    \
297     ix86_builtins[(int) IX86_BUILTIN_CFSTRING]                                  \
298       = darwin_init_cfstring_builtins ((unsigned) (IX86_BUILTIN_CFSTRING)); \
299     darwin_rename_builtins ();                                                            \
300   } while(0)
301 
302 /* Define the shadow offset for asan.  */
303 #undef SUBTARGET_SHADOW_OFFSET
304 #define SUBTARGET_SHADOW_OFFSET         \
305   (TARGET_LP64 ? HOST_WIDE_INT_1 << 44 : HOST_WIDE_INT_1 << 29)
306 
307 #undef CLEAR_INSN_CACHE
308 #define CLEAR_INSN_CACHE(beg, end)                                    \
309   extern void sys_icache_invalidate(void *start, size_t len);         \
310   sys_icache_invalidate ((beg), (size_t)((end)-(beg)))
311