1 /* Machine description for AArch64 architecture.
2    Copyright (C) 2009-2013 Free Software Foundation, Inc.
3    Contributed by ARM Ltd.
4 
5    This file is part of GCC.
6 
7    GCC is free software; you can redistribute it and/or modify it
8    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, but
13    WITHOUT ANY WARRANTY; without even the implied warranty of
14    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
15    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 
22 #ifndef GCC_AARCH64_H
23 #define GCC_AARCH64_H
24 
25 /* Target CPU builtins.  */
26 #define TARGET_CPU_CPP_BUILTINS()			\
27   do							\
28     {							\
29       builtin_define ("__aarch64__");			\
30       if (TARGET_BIG_END)				\
31 	builtin_define ("__AARCH64EB__");		\
32       else						\
33 	builtin_define ("__AARCH64EL__");		\
34 							\
35       switch (aarch64_cmodel)				\
36 	{						\
37 	  case AARCH64_CMODEL_TINY:			\
38 	  case AARCH64_CMODEL_TINY_PIC:			\
39 	    builtin_define ("__AARCH64_CMODEL_TINY__");	\
40 	    break;					\
41 	  case AARCH64_CMODEL_SMALL:			\
42 	  case AARCH64_CMODEL_SMALL_PIC:		\
43 	    builtin_define ("__AARCH64_CMODEL_SMALL__");\
44 	    break;					\
45 	  case AARCH64_CMODEL_LARGE:			\
46 	    builtin_define ("__AARCH64_CMODEL_LARGE__");	\
47 	    break;					\
48 	  default:					\
49 	    break;					\
50 	}						\
51 							\
52     } while (0)
53 
54 
55 
56 /* Target machine storage layout.  */
57 
58 #define PROMOTE_MODE(MODE, UNSIGNEDP, TYPE)	\
59   if (GET_MODE_CLASS (MODE) == MODE_INT		\
60       && GET_MODE_SIZE (MODE) < 4)		\
61     {						\
62       if (MODE == QImode || MODE == HImode)	\
63 	{					\
64 	  MODE = SImode;			\
65 	}					\
66     }
67 
68 /* Bits are always numbered from the LSBit.  */
69 #define BITS_BIG_ENDIAN 0
70 
71 /* Big/little-endian flavour.  */
72 #define BYTES_BIG_ENDIAN (TARGET_BIG_END != 0)
73 #define WORDS_BIG_ENDIAN (BYTES_BIG_ENDIAN)
74 
75 /* AdvSIMD is supported in the default configuration, unless disabled by
76    -mgeneral-regs-only.  */
77 #define TARGET_SIMD !TARGET_GENERAL_REGS_ONLY
78 #define TARGET_FLOAT !TARGET_GENERAL_REGS_ONLY
79 
80 #define UNITS_PER_WORD		8
81 
82 #define UNITS_PER_VREG		16
83 
84 #define PARM_BOUNDARY		64
85 
86 #define STACK_BOUNDARY		128
87 
88 #define FUNCTION_BOUNDARY	32
89 
90 #define EMPTY_FIELD_BOUNDARY	32
91 
92 #define BIGGEST_ALIGNMENT	128
93 
94 #define SHORT_TYPE_SIZE		16
95 
96 #define INT_TYPE_SIZE		32
97 
98 #define LONG_TYPE_SIZE		64	/* XXX This should be an option */
99 
100 #define LONG_LONG_TYPE_SIZE	64
101 
102 #define FLOAT_TYPE_SIZE		32
103 
104 #define DOUBLE_TYPE_SIZE	64
105 
106 #define LONG_DOUBLE_TYPE_SIZE	128
107 
108 /* The architecture reserves all bits of the address for hardware use,
109    so the vbit must go into the delta field of pointers to member
110    functions.  This is the same config as that in the AArch32
111    port.  */
112 #define TARGET_PTRMEMFUNC_VBIT_LOCATION ptrmemfunc_vbit_in_delta
113 
114 /* Make strings word-aligned so that strcpy from constants will be
115    faster.  */
116 #define CONSTANT_ALIGNMENT(EXP, ALIGN)		\
117   ((TREE_CODE (EXP) == STRING_CST		\
118     && !optimize_size				\
119     && (ALIGN) < BITS_PER_WORD)			\
120    ? BITS_PER_WORD : ALIGN)
121 
122 #define DATA_ALIGNMENT(EXP, ALIGN)		\
123   ((((ALIGN) < BITS_PER_WORD)			\
124     && (TREE_CODE (EXP) == ARRAY_TYPE		\
125 	|| TREE_CODE (EXP) == UNION_TYPE	\
126 	|| TREE_CODE (EXP) == RECORD_TYPE))	\
127    ? BITS_PER_WORD : (ALIGN))
128 
129 #define LOCAL_ALIGNMENT(EXP, ALIGN) DATA_ALIGNMENT(EXP, ALIGN)
130 
131 #define STRUCTURE_SIZE_BOUNDARY		8
132 
133 /* Defined by the ABI */
134 #define WCHAR_TYPE "unsigned int"
135 #define WCHAR_TYPE_SIZE			32
136 
137 /* Using long long breaks -ansi and -std=c90, so these will need to be
138    made conditional for an LLP64 ABI.  */
139 
140 #define SIZE_TYPE	"long unsigned int"
141 
142 #define PTRDIFF_TYPE	"long int"
143 
144 #define PCC_BITFIELD_TYPE_MATTERS	1
145 
146 
147 /* Instruction tuning/selection flags.  */
148 
149 /* Bit values used to identify processor capabilities.  */
150 #define AARCH64_FL_SIMD       (1 << 0)	/* Has SIMD instructions.  */
151 #define AARCH64_FL_FP         (1 << 1)	/* Has FP.  */
152 #define AARCH64_FL_CRYPTO     (1 << 2)	/* Has crypto.  */
153 #define AARCH64_FL_SLOWMUL    (1 << 3)	/* A slow multiply core.  */
154 
155 /* Has FP and SIMD.  */
156 #define AARCH64_FL_FPSIMD     (AARCH64_FL_FP | AARCH64_FL_SIMD)
157 
158 /* Has FP without SIMD.  */
159 #define AARCH64_FL_FPQ16      (AARCH64_FL_FP & ~AARCH64_FL_SIMD)
160 
161 /* Architecture flags that effect instruction selection.  */
162 #define AARCH64_FL_FOR_ARCH8       (AARCH64_FL_FPSIMD)
163 
164 /* Macros to test ISA flags.  */
165 extern unsigned long aarch64_isa_flags;
166 #define AARCH64_ISA_CRYPTO         (aarch64_isa_flags & AARCH64_FL_CRYPTO)
167 #define AARCH64_ISA_FP             (aarch64_isa_flags & AARCH64_FL_FP)
168 #define AARCH64_ISA_SIMD           (aarch64_isa_flags & AARCH64_FL_SIMD)
169 
170 /* Macros to test tuning flags.  */
171 extern unsigned long aarch64_tune_flags;
172 #define AARCH64_TUNE_SLOWMUL       (aarch64_tune_flags & AARCH64_FL_SLOWMUL)
173 
174 
175 /* Standard register usage.  */
176 
177 /* 31 64-bit general purpose registers R0-R30:
178    R30		LR (link register)
179    R29		FP (frame pointer)
180    R19-R28	Callee-saved registers
181    R18		The platform register; use as temporary register.
182    R17		IP1 The second intra-procedure-call temporary register
183 		(can be used by call veneers and PLT code); otherwise use
184 		as a temporary register
185    R16		IP0 The first intra-procedure-call temporary register (can
186 		be used by call veneers and PLT code); otherwise use as a
187 		temporary register
188    R9-R15	Temporary registers
189    R8		Structure value parameter / temporary register
190    R0-R7	Parameter/result registers
191 
192    SP		stack pointer, encoded as X/R31 where permitted.
193    ZR		zero register, encoded as X/R31 elsewhere
194 
195    32 x 128-bit floating-point/vector registers
196    V16-V31	Caller-saved (temporary) registers
197    V8-V15	Callee-saved registers
198    V0-V7	Parameter/result registers
199 
200    The vector register V0 holds scalar B0, H0, S0 and D0 in its least
201    significant bits.  Unlike AArch32 S1 is not packed into D0,
202    etc.  */
203 
204 /* Note that we don't mark X30 as a call-clobbered register.  The idea is
205    that it's really the call instructions themselves which clobber X30.
206    We don't care what the called function does with it afterwards.
207 
208    This approach makes it easier to implement sibcalls.  Unlike normal
209    calls, sibcalls don't clobber X30, so the register reaches the
210    called function intact.  EPILOGUE_USES says that X30 is useful
211    to the called function.  */
212 
213 #define FIXED_REGISTERS					\
214   {							\
215     0, 0, 0, 0,   0, 0, 0, 0,	/* R0 - R7 */		\
216     0, 0, 0, 0,   0, 0, 0, 0,	/* R8 - R15 */		\
217     0, 0, 0, 0,   0, 0, 0, 0,	/* R16 - R23 */		\
218     0, 0, 0, 0,   0, 1, 0, 1,	/* R24 - R30, SP */	\
219     0, 0, 0, 0,   0, 0, 0, 0,   /* V0 - V7 */           \
220     0, 0, 0, 0,   0, 0, 0, 0,   /* V8 - V15 */		\
221     0, 0, 0, 0,   0, 0, 0, 0,   /* V16 - V23 */         \
222     0, 0, 0, 0,   0, 0, 0, 0,   /* V24 - V31 */         \
223     1, 1, 1,			/* SFP, AP, CC */	\
224   }
225 
226 #define CALL_USED_REGISTERS				\
227   {							\
228     1, 1, 1, 1,   1, 1, 1, 1,	/* R0 - R7 */		\
229     1, 1, 1, 1,   1, 1, 1, 1,	/* R8 - R15 */		\
230     1, 1, 1, 0,   0, 0, 0, 0,	/* R16 - R23 */		\
231     0, 0, 0, 0,   0, 1, 0, 1,	/* R24 - R30, SP */	\
232     1, 1, 1, 1,   1, 1, 1, 1,	/* V0 - V7 */		\
233     0, 0, 0, 0,   0, 0, 0, 0,	/* V8 - V15 */		\
234     1, 1, 1, 1,   1, 1, 1, 1,   /* V16 - V23 */         \
235     1, 1, 1, 1,   1, 1, 1, 1,   /* V24 - V31 */         \
236     1, 1, 1,			/* SFP, AP, CC */	\
237   }
238 
239 #define REGISTER_NAMES						\
240   {								\
241     "x0",  "x1",  "x2",  "x3",  "x4",  "x5",  "x6",  "x7",	\
242     "x8",  "x9",  "x10", "x11", "x12", "x13", "x14", "x15",	\
243     "x16", "x17", "x18", "x19", "x20", "x21", "x22", "x23",	\
244     "x24", "x25", "x26", "x27", "x28", "x29", "x30", "sp",	\
245     "v0",  "v1",  "v2",  "v3",  "v4",  "v5",  "v6",  "v7",	\
246     "v8",  "v9",  "v10", "v11", "v12", "v13", "v14", "v15",	\
247     "v16", "v17", "v18", "v19", "v20", "v21", "v22", "v23",	\
248     "v24", "v25", "v26", "v27", "v28", "v29", "v30", "v31",	\
249     "sfp", "ap",  "cc",						\
250   }
251 
252 /* Generate the register aliases for core register N */
253 #define R_ALIASES(N) {"r" # N, R0_REGNUM + (N)}, \
254                      {"w" # N, R0_REGNUM + (N)}
255 
256 #define V_ALIASES(N) {"q" # N, V0_REGNUM + (N)}, \
257                      {"d" # N, V0_REGNUM + (N)}, \
258                      {"s" # N, V0_REGNUM + (N)}, \
259                      {"h" # N, V0_REGNUM + (N)}, \
260                      {"b" # N, V0_REGNUM + (N)}
261 
262 /* Provide aliases for all of the ISA defined register name forms.
263    These aliases are convenient for use in the clobber lists of inline
264    asm statements.  */
265 
266 #define ADDITIONAL_REGISTER_NAMES \
267   { R_ALIASES(0),  R_ALIASES(1),  R_ALIASES(2),  R_ALIASES(3),  \
268     R_ALIASES(4),  R_ALIASES(5),  R_ALIASES(6),  R_ALIASES(7),  \
269     R_ALIASES(8),  R_ALIASES(9),  R_ALIASES(10), R_ALIASES(11), \
270     R_ALIASES(12), R_ALIASES(13), R_ALIASES(14), R_ALIASES(15), \
271     R_ALIASES(16), R_ALIASES(17), R_ALIASES(18), R_ALIASES(19), \
272     R_ALIASES(20), R_ALIASES(21), R_ALIASES(22), R_ALIASES(23), \
273     R_ALIASES(24), R_ALIASES(25), R_ALIASES(26), R_ALIASES(27), \
274     R_ALIASES(28), R_ALIASES(29), R_ALIASES(30), /* 31 omitted  */ \
275     V_ALIASES(0),  V_ALIASES(1),  V_ALIASES(2),  V_ALIASES(3),  \
276     V_ALIASES(4),  V_ALIASES(5),  V_ALIASES(6),  V_ALIASES(7),  \
277     V_ALIASES(8),  V_ALIASES(9),  V_ALIASES(10), V_ALIASES(11), \
278     V_ALIASES(12), V_ALIASES(13), V_ALIASES(14), V_ALIASES(15), \
279     V_ALIASES(16), V_ALIASES(17), V_ALIASES(18), V_ALIASES(19), \
280     V_ALIASES(20), V_ALIASES(21), V_ALIASES(22), V_ALIASES(23), \
281     V_ALIASES(24), V_ALIASES(25), V_ALIASES(26), V_ALIASES(27), \
282     V_ALIASES(28), V_ALIASES(29), V_ALIASES(30), V_ALIASES(31)  \
283   }
284 
285 /* Say that the epilogue uses the return address register.  Note that
286    in the case of sibcalls, the values "used by the epilogue" are
287    considered live at the start of the called function.  */
288 
289 #define EPILOGUE_USES(REGNO) \
290   ((REGNO) == LR_REGNUM)
291 
292 /* EXIT_IGNORE_STACK should be nonzero if, when returning from a function,
293    the stack pointer does not matter.  The value is tested only in
294    functions that have frame pointers.  */
295 #define EXIT_IGNORE_STACK	1
296 
297 #define STATIC_CHAIN_REGNUM		R18_REGNUM
298 #define HARD_FRAME_POINTER_REGNUM	R29_REGNUM
299 #define FRAME_POINTER_REGNUM		SFP_REGNUM
300 #define STACK_POINTER_REGNUM		SP_REGNUM
301 #define ARG_POINTER_REGNUM		AP_REGNUM
302 #define FIRST_PSEUDO_REGISTER		67
303 
304 /* The number of (integer) argument register available.  */
305 #define NUM_ARG_REGS			8
306 #define NUM_FP_ARG_REGS			8
307 
308 /* A Homogeneous Floating-Point or Short-Vector Aggregate may have at most
309    four members.  */
310 #define HA_MAX_NUM_FLDS		4
311 
312 /* External dwarf register number scheme.  These number are used to
313    identify registers in dwarf debug information, the values are
314    defined by the AArch64 ABI.  The numbering scheme is independent of
315    GCC's internal register numbering scheme.  */
316 
317 #define AARCH64_DWARF_R0        0
318 
319 /* The number of R registers, note 31! not 32.  */
320 #define AARCH64_DWARF_NUMBER_R 31
321 
322 #define AARCH64_DWARF_SP       31
323 #define AARCH64_DWARF_V0       64
324 
325 /* The number of V registers.  */
326 #define AARCH64_DWARF_NUMBER_V 32
327 
328 /* For signal frames we need to use an alternative return column.  This
329    value must not correspond to a hard register and must be out of the
330    range of DWARF_FRAME_REGNUM().  */
331 #define DWARF_ALT_FRAME_RETURN_COLUMN   \
332   (AARCH64_DWARF_V0 + AARCH64_DWARF_NUMBER_V)
333 
334 /* We add 1 extra frame register for use as the
335    DWARF_ALT_FRAME_RETURN_COLUMN.  */
336 #define DWARF_FRAME_REGISTERS           (DWARF_ALT_FRAME_RETURN_COLUMN + 1)
337 
338 
339 #define DBX_REGISTER_NUMBER(REGNO)	aarch64_dbx_register_number (REGNO)
340 /* Provide a definition of DWARF_FRAME_REGNUM here so that fallback unwinders
341    can use DWARF_ALT_FRAME_RETURN_COLUMN defined below.  This is just the same
342    as the default definition in dwarf2out.c.  */
343 #undef DWARF_FRAME_REGNUM
344 #define DWARF_FRAME_REGNUM(REGNO)	DBX_REGISTER_NUMBER (REGNO)
345 
346 #define DWARF_FRAME_RETURN_COLUMN	DWARF_FRAME_REGNUM (LR_REGNUM)
347 
348 #define HARD_REGNO_NREGS(REGNO, MODE)	aarch64_hard_regno_nregs (REGNO, MODE)
349 
350 #define HARD_REGNO_MODE_OK(REGNO, MODE)	aarch64_hard_regno_mode_ok (REGNO, MODE)
351 
352 #define MODES_TIEABLE_P(MODE1, MODE2)			\
353   (GET_MODE_CLASS (MODE1) == GET_MODE_CLASS (MODE2))
354 
355 #define DWARF2_UNWIND_INFO 1
356 
357 /* Use R0 through R3 to pass exception handling information.  */
358 #define EH_RETURN_DATA_REGNO(N) \
359   ((N) < 4 ? ((unsigned int) R0_REGNUM + (N)) : INVALID_REGNUM)
360 
361 /* Select a format to encode pointers in exception handling data.  */
362 #define ASM_PREFERRED_EH_DATA_FORMAT(CODE, GLOBAL) \
363   aarch64_asm_preferred_eh_data_format ((CODE), (GLOBAL))
364 
365 /* The register that holds the return address in exception handlers.  */
366 #define AARCH64_EH_STACKADJ_REGNUM	(R0_REGNUM + 4)
367 #define EH_RETURN_STACKADJ_RTX	gen_rtx_REG (Pmode, AARCH64_EH_STACKADJ_REGNUM)
368 
369 /* Don't use __builtin_setjmp until we've defined it.  */
370 #undef DONT_USE_BUILTIN_SETJMP
371 #define DONT_USE_BUILTIN_SETJMP 1
372 
373 /* Register in which the structure value is to be returned.  */
374 #define AARCH64_STRUCT_VALUE_REGNUM R8_REGNUM
375 
376 /* Non-zero if REGNO is part of the Core register set.
377 
378    The rather unusual way of expressing this check is to avoid
379    warnings when building the compiler when R0_REGNUM is 0 and REGNO
380    is unsigned.  */
381 #define GP_REGNUM_P(REGNO)						\
382   (((unsigned) (REGNO - R0_REGNUM)) <= (R30_REGNUM - R0_REGNUM))
383 
384 #define FP_REGNUM_P(REGNO)			\
385   (((unsigned) (REGNO - V0_REGNUM)) <= (V31_REGNUM - V0_REGNUM))
386 
387 #define FP_LO_REGNUM_P(REGNO)            \
388   (((unsigned) (REGNO - V0_REGNUM)) <= (V15_REGNUM - V0_REGNUM))
389 
390 
391 /* Register and constant classes.  */
392 
393 enum reg_class
394 {
395   NO_REGS,
396   CORE_REGS,
397   GENERAL_REGS,
398   STACK_REG,
399   POINTER_REGS,
400   FP_LO_REGS,
401   FP_REGS,
402   ALL_REGS,
403   LIM_REG_CLASSES		/* Last */
404 };
405 
406 #define N_REG_CLASSES	((int) LIM_REG_CLASSES)
407 
408 #define REG_CLASS_NAMES				\
409 {						\
410   "NO_REGS",					\
411   "CORE_REGS",					\
412   "GENERAL_REGS",				\
413   "STACK_REG",					\
414   "POINTER_REGS",				\
415   "FP_LO_REGS",					\
416   "FP_REGS",					\
417   "ALL_REGS"					\
418 }
419 
420 #define REG_CLASS_CONTENTS						\
421 {									\
422   { 0x00000000, 0x00000000, 0x00000000 },	/* NO_REGS */		\
423   { 0x7fffffff, 0x00000000, 0x00000003 },	/* CORE_REGS */		\
424   { 0x7fffffff, 0x00000000, 0x00000003 },	/* GENERAL_REGS */	\
425   { 0x80000000, 0x00000000, 0x00000000 },	/* STACK_REG */		\
426   { 0xffffffff, 0x00000000, 0x00000003 },	/* POINTER_REGS */	\
427   { 0x00000000, 0x0000ffff, 0x00000000 },       /* FP_LO_REGS  */	\
428   { 0x00000000, 0xffffffff, 0x00000000 },       /* FP_REGS  */		\
429   { 0xffffffff, 0xffffffff, 0x00000007 }	/* ALL_REGS */		\
430 }
431 
432 #define REGNO_REG_CLASS(REGNO)	aarch64_regno_regclass (REGNO)
433 
434 #define INDEX_REG_CLASS	CORE_REGS
435 #define BASE_REG_CLASS  POINTER_REGS
436 
437 /* Register pairs used to eliminate unneeded registers that point intoi
438    the stack frame.  */
439 #define ELIMINABLE_REGS							\
440 {									\
441   { ARG_POINTER_REGNUM,		STACK_POINTER_REGNUM		},	\
442   { ARG_POINTER_REGNUM,		HARD_FRAME_POINTER_REGNUM	},	\
443   { FRAME_POINTER_REGNUM,	STACK_POINTER_REGNUM		},	\
444   { FRAME_POINTER_REGNUM,	HARD_FRAME_POINTER_REGNUM	},	\
445 }
446 
447 #define INITIAL_ELIMINATION_OFFSET(FROM, TO, OFFSET) \
448   (OFFSET) = aarch64_initial_elimination_offset (FROM, TO)
449 
450 /* CPU/ARCH option handling.  */
451 #include "config/aarch64/aarch64-opts.h"
452 
453 enum target_cpus
454 {
455 #define AARCH64_CORE(NAME, IDENT, ARCH, FLAGS, COSTS) \
456   TARGET_CPU_##IDENT,
457 #include "aarch64-cores.def"
458 #undef AARCH64_CORE
459   TARGET_CPU_generic
460 };
461 
462 /* If there is no CPU defined at configure, use "generic" as default.  */
463 #ifndef TARGET_CPU_DEFAULT
464 #define TARGET_CPU_DEFAULT \
465   (TARGET_CPU_generic | (AARCH64_CPU_DEFAULT_FLAGS << 6))
466 #endif
467 
468 /* The processor for which instructions should be scheduled.  */
469 extern enum aarch64_processor aarch64_tune;
470 
471 /* RTL generation support.  */
472 #define INIT_EXPANDERS aarch64_init_expanders ()
473 
474 
475 /* Stack layout; function entry, exit and calling.  */
476 #define STACK_GROWS_DOWNWARD	1
477 
478 #define FRAME_GROWS_DOWNWARD	0
479 
480 #define STARTING_FRAME_OFFSET	0
481 
482 #define ACCUMULATE_OUTGOING_ARGS	1
483 
484 #define FIRST_PARM_OFFSET(FNDECL) 0
485 
486 /* Fix for VFP */
487 #define LIBCALL_VALUE(MODE)  \
488   gen_rtx_REG (MODE, FLOAT_MODE_P (MODE) ? V0_REGNUM : R0_REGNUM)
489 
490 #define DEFAULT_PCC_STRUCT_RETURN 0
491 
492 #define AARCH64_ROUND_UP(X, ALIGNMENT) \
493   (((X) + ((ALIGNMENT) - 1)) & ~((ALIGNMENT) - 1))
494 
495 #define AARCH64_ROUND_DOWN(X, ALIGNMENT) \
496   ((X) & ~((ALIGNMENT) - 1))
497 
498 #ifdef HOST_WIDE_INT
499 struct GTY (()) aarch64_frame
500 {
501   HOST_WIDE_INT reg_offset[FIRST_PSEUDO_REGISTER];
502   HOST_WIDE_INT saved_regs_size;
503   /* Padding if needed after the all the callee save registers have
504      been saved.  */
505   HOST_WIDE_INT padding0;
506   HOST_WIDE_INT hardfp_offset;	/* HARD_FRAME_POINTER_REGNUM */
507   HOST_WIDE_INT fp_lr_offset;	/* Space needed for saving fp and/or lr */
508 
509   bool laid_out;
510 };
511 
512 typedef struct GTY (()) machine_function
513 {
514   struct aarch64_frame frame;
515 
516   /* The number of extra stack bytes taken up by register varargs.
517      This area is allocated by the callee at the very top of the frame.  */
518   HOST_WIDE_INT saved_varargs_size;
519 
520 } machine_function;
521 #endif
522 
523 
524 /* Which ABI to use.  */
525 enum arm_abi_type
526 {
527   ARM_ABI_AAPCS64
528 };
529 
530 enum arm_pcs
531 {
532   ARM_PCS_AAPCS64,		/* Base standard AAPCS for 64 bit.  */
533   ARM_PCS_UNKNOWN
534 };
535 
536 
537 extern enum arm_abi_type arm_abi;
538 extern enum arm_pcs arm_pcs_variant;
539 #ifndef ARM_DEFAULT_ABI
540 #define ARM_DEFAULT_ABI ARM_ABI_AAPCS64
541 #endif
542 
543 #ifndef ARM_DEFAULT_PCS
544 #define ARM_DEFAULT_PCS ARM_PCS_AAPCS64
545 #endif
546 
547 /* We can't use enum machine_mode inside a generator file because it
548    hasn't been created yet; we shouldn't be using any code that
549    needs the real definition though, so this ought to be safe.  */
550 #ifdef GENERATOR_FILE
551 #define MACHMODE int
552 #else
553 #include "insn-modes.h"
554 #define MACHMODE enum machine_mode
555 #endif
556 
557 
558 /* AAPCS related state tracking.  */
559 typedef struct
560 {
561   enum arm_pcs pcs_variant;
562   int aapcs_arg_processed;	/* No need to lay out this argument again.  */
563   int aapcs_ncrn;		/* Next Core register number.  */
564   int aapcs_nextncrn;		/* Next next core register number.  */
565   int aapcs_nvrn;		/* Next Vector register number.  */
566   int aapcs_nextnvrn;		/* Next Next Vector register number.  */
567   rtx aapcs_reg;		/* Register assigned to this argument.  This
568 				   is NULL_RTX if this parameter goes on
569 				   the stack.  */
570   MACHMODE aapcs_vfp_rmode;
571   int aapcs_stack_words;	/* If the argument is passed on the stack, this
572 				   is the number of words needed, after rounding
573 				   up.  Only meaningful when
574 				   aapcs_reg == NULL_RTX.  */
575   int aapcs_stack_size;		/* The total size (in words, per 8 byte) of the
576 				   stack arg area so far.  */
577 } CUMULATIVE_ARGS;
578 
579 #define FUNCTION_ARG_PADDING(MODE, TYPE) \
580   (aarch64_pad_arg_upward (MODE, TYPE) ? upward : downward)
581 
582 #define BLOCK_REG_PADDING(MODE, TYPE, FIRST) \
583   (aarch64_pad_reg_upward (MODE, TYPE, FIRST) ? upward : downward)
584 
585 #define PAD_VARARGS_DOWN	0
586 
587 #define INIT_CUMULATIVE_ARGS(CUM, FNTYPE, LIBNAME, FNDECL, N_NAMED_ARGS) \
588   aarch64_init_cumulative_args (&(CUM), FNTYPE, LIBNAME, FNDECL, N_NAMED_ARGS)
589 
590 #define FUNCTION_ARG_REGNO_P(REGNO) \
591   aarch64_function_arg_regno_p(REGNO)
592 
593 
594 /* ISA Features.  */
595 
596 /* Addressing modes, etc.  */
597 #define HAVE_POST_INCREMENT	1
598 #define HAVE_PRE_INCREMENT	1
599 #define HAVE_POST_DECREMENT	1
600 #define HAVE_PRE_DECREMENT	1
601 #define HAVE_POST_MODIFY_DISP	1
602 #define HAVE_PRE_MODIFY_DISP	1
603 
604 #define MAX_REGS_PER_ADDRESS	2
605 
606 #define CONSTANT_ADDRESS_P(X)		aarch64_constant_address_p(X)
607 
608 /* Try a machine-dependent way of reloading an illegitimate address
609    operand.  If we find one, push the reload and jump to WIN.  This
610    macro is used in only one place: `find_reloads_address' in reload.c.  */
611 
612 #define LEGITIMIZE_RELOAD_ADDRESS(X, MODE, OPNUM, TYPE, IND_L, WIN)	     \
613 do {									     \
614   rtx new_x = aarch64_legitimize_reload_address (&(X), MODE, OPNUM, TYPE,    \
615 						 IND_L);		     \
616   if (new_x)								     \
617     {									     \
618       X = new_x;							     \
619       goto WIN;								     \
620     }									     \
621 } while (0)
622 
623 #define REGNO_OK_FOR_BASE_P(REGNO)	\
624   aarch64_regno_ok_for_base_p (REGNO, true)
625 
626 #define REGNO_OK_FOR_INDEX_P(REGNO) \
627   aarch64_regno_ok_for_index_p (REGNO, true)
628 
629 #define LEGITIMATE_PIC_OPERAND_P(X) \
630   aarch64_legitimate_pic_operand_p (X)
631 
632 #define CASE_VECTOR_MODE Pmode
633 
634 #define DEFAULT_SIGNED_CHAR 0
635 
636 /* An integer expression for the size in bits of the largest integer machine
637    mode that should actually be used.  We allow pairs of registers.  */
638 #define MAX_FIXED_MODE_SIZE GET_MODE_BITSIZE (TImode)
639 
640 /* Maximum bytes moved by a single instruction (load/store pair).  */
641 #define MOVE_MAX (UNITS_PER_WORD * 2)
642 
643 /* The base cost overhead of a memcpy call, for MOVE_RATIO and friends.  */
644 #define AARCH64_CALL_RATIO 8
645 
646 /* When optimizing for size, give a better estimate of the length of a memcpy
647    call, but use the default otherwise.  But move_by_pieces_ninsns() counts
648    memory-to-memory moves, and we'll have to generate a load & store for each,
649    so halve the value to take that into account.  */
650 #define MOVE_RATIO(speed) \
651   (((speed) ? 15 : AARCH64_CALL_RATIO) / 2)
652 
653 /* For CLEAR_RATIO, when optimizing for size, give a better estimate
654    of the length of a memset call, but use the default otherwise.  */
655 #define CLEAR_RATIO(speed) \
656   ((speed) ? 15 : AARCH64_CALL_RATIO)
657 
658 /* SET_RATIO is similar to CLEAR_RATIO, but for a non-zero constant, so when
659    optimizing for size adjust the ratio to account for the overhead of loading
660    the constant.  */
661 #define SET_RATIO(speed) \
662   ((speed) ? 15 : AARCH64_CALL_RATIO - 2)
663 
664 /* STORE_BY_PIECES_P can be used when copying a constant string, but
665    in that case each 64-bit chunk takes 5 insns instead of 2 (LDR/STR).
666    For now we always fail this and let the move_by_pieces code copy
667    the string from read-only memory.  */
668 #define STORE_BY_PIECES_P(SIZE, ALIGN) 0
669 
670 /* Disable auto-increment in move_by_pieces et al.  Use of auto-increment is
671    rarely a good idea in straight-line code since it adds an extra address
672    dependency between each instruction.  Better to use incrementing offsets.  */
673 #define USE_LOAD_POST_INCREMENT(MODE)   0
674 #define USE_LOAD_POST_DECREMENT(MODE)   0
675 #define USE_LOAD_PRE_INCREMENT(MODE)    0
676 #define USE_LOAD_PRE_DECREMENT(MODE)    0
677 #define USE_STORE_POST_INCREMENT(MODE)  0
678 #define USE_STORE_POST_DECREMENT(MODE)  0
679 #define USE_STORE_PRE_INCREMENT(MODE)   0
680 #define USE_STORE_PRE_DECREMENT(MODE)   0
681 
682 /* ?? #define WORD_REGISTER_OPERATIONS  */
683 
684 /* Define if loading from memory in MODE, an integral mode narrower than
685    BITS_PER_WORD will either zero-extend or sign-extend.  The value of this
686    macro should be the code that says which one of the two operations is
687    implicitly done, or UNKNOWN if none.  */
688 #define LOAD_EXTEND_OP(MODE) ZERO_EXTEND
689 
690 /* Define this macro to be non-zero if instructions will fail to work
691    if given data not on the nominal alignment.  */
692 #define STRICT_ALIGNMENT		TARGET_STRICT_ALIGN
693 
694 /* Define this macro to be non-zero if accessing less than a word of
695    memory is no faster than accessing a word of memory, i.e., if such
696    accesses require more than one instruction or if there is no
697    difference in cost.
698    Although there's no difference in instruction count or cycles,
699    in AArch64 we don't want to expand to a sub-word to a 64-bit access
700    if we don't have to, for power-saving reasons.  */
701 #define SLOW_BYTE_ACCESS		0
702 
703 #define TRULY_NOOP_TRUNCATION(OUTPREC, INPREC) 1
704 
705 #define NO_FUNCTION_CSE	1
706 
707 #define Pmode		DImode
708 #define FUNCTION_MODE	Pmode
709 
710 #define SELECT_CC_MODE(OP, X, Y)	aarch64_select_cc_mode (OP, X, Y)
711 
712 #define REVERSE_CONDITION(CODE, MODE)		\
713   (((MODE) == CCFPmode || (MODE) == CCFPEmode)	\
714    ? reverse_condition_maybe_unordered (CODE)	\
715    : reverse_condition (CODE))
716 
717 #define CLZ_DEFINED_VALUE_AT_ZERO(MODE, VALUE) \
718   ((VALUE) = ((MODE) == SImode ? 32 : 64), 2)
719 #define CTZ_DEFINED_VALUE_AT_ZERO(MODE, VALUE) \
720   ((VALUE) = ((MODE) == SImode ? 32 : 64), 2)
721 
722 #define INCOMING_RETURN_ADDR_RTX gen_rtx_REG (Pmode, LR_REGNUM)
723 
724 #define RETURN_ADDR_RTX aarch64_return_addr
725 
726 #define TRAMPOLINE_SIZE	aarch64_trampoline_size ()
727 
728 /* Trampolines contain dwords, so must be dword aligned.  */
729 #define TRAMPOLINE_ALIGNMENT 64
730 
731 /* Put trampolines in the text section so that mapping symbols work
732    correctly.  */
733 #define TRAMPOLINE_SECTION text_section
734 
735 /* Costs, etc.  */
736 #define MEMORY_MOVE_COST(M, CLASS, IN) \
737   (GET_MODE_SIZE (M) < 8 ? 8 : GET_MODE_SIZE (M))
738 
739 /* To start with.  */
740 #define BRANCH_COST(SPEED_P, PREDICTABLE_P) 2
741 
742 
743 /* Assembly output.  */
744 
745 /* For now we'll make all jump tables pc-relative.  */
746 #define CASE_VECTOR_PC_RELATIVE	1
747 
748 #define CASE_VECTOR_SHORTEN_MODE(min, max, body)	\
749   ((min < -0x1fff0 || max > 0x1fff0) ? SImode		\
750    : (min < -0x1f0 || max > 0x1f0) ? HImode		\
751    : QImode)
752 
753 /* Jump table alignment is explicit in ASM_OUTPUT_CASE_LABEL.  */
754 #define ADDR_VEC_ALIGN(JUMPTABLE) 0
755 
756 #define PRINT_OPERAND(STREAM, X, CODE) aarch64_print_operand (STREAM, X, CODE)
757 
758 #define PRINT_OPERAND_ADDRESS(STREAM, X) \
759   aarch64_print_operand_address (STREAM, X)
760 
761 #define FUNCTION_PROFILER(STREAM, LABELNO) \
762   aarch64_function_profiler (STREAM, LABELNO)
763 
764 /* For some reason, the Linux headers think they know how to define
765    these macros.  They don't!!!  */
766 #undef ASM_APP_ON
767 #undef ASM_APP_OFF
768 #define ASM_APP_ON	"\t" ASM_COMMENT_START " Start of user assembly\n"
769 #define ASM_APP_OFF	"\t" ASM_COMMENT_START " End of user assembly\n"
770 
771 #define CONSTANT_POOL_BEFORE_FUNCTION 0
772 
773 /* This definition should be relocated to aarch64-elf-raw.h.  This macro
774    should be undefined in aarch64-linux.h and a clear_cache pattern
775    implmented to emit either the call to __aarch64_sync_cache_range()
776    directly or preferably the appropriate sycall or cache clear
777    instructions inline.  */
778 #define CLEAR_INSN_CACHE(beg, end)				\
779   extern void  __aarch64_sync_cache_range (void *, void *);	\
780   __aarch64_sync_cache_range (beg, end)
781 
782 /*  VFP registers may only be accessed in the mode they
783    were set.  */
784 #define CANNOT_CHANGE_MODE_CLASS(FROM, TO, CLASS)	\
785   (GET_MODE_SIZE (FROM) != GET_MODE_SIZE (TO)		\
786    ? reg_classes_intersect_p (FP_REGS, (CLASS))		\
787    : 0)
788 
789 
790 #define SHIFT_COUNT_TRUNCATED !TARGET_SIMD
791 
792 /* Callee only saves lower 64-bits of a 128-bit register.  Tell the
793    compiler the callee clobbers the top 64-bits when restoring the
794    bottom 64-bits.  */
795 #define HARD_REGNO_CALL_PART_CLOBBERED(REGNO, MODE) \
796 		(FP_REGNUM_P (REGNO) && GET_MODE_SIZE (MODE) > 8)
797 
798 /* Check TLS Descriptors mechanism is selected.  */
799 #define TARGET_TLS_DESC (aarch64_tls_dialect == TLS_DESCRIPTORS)
800 
801 extern enum aarch64_code_model aarch64_cmodel;
802 
803 /* When using the tiny addressing model conditional and unconditional branches
804    can span the whole of the available address space (1MB).  */
805 #define HAS_LONG_COND_BRANCH				\
806   (aarch64_cmodel == AARCH64_CMODEL_TINY		\
807    || aarch64_cmodel == AARCH64_CMODEL_TINY_PIC)
808 
809 #define HAS_LONG_UNCOND_BRANCH				\
810   (aarch64_cmodel == AARCH64_CMODEL_TINY		\
811    || aarch64_cmodel == AARCH64_CMODEL_TINY_PIC)
812 
813 /* Modes valid for AdvSIMD Q registers.  */
814 #define AARCH64_VALID_SIMD_QREG_MODE(MODE) \
815   ((MODE) == V4SImode || (MODE) == V8HImode || (MODE) == V16QImode \
816    || (MODE) == V4SFmode || (MODE) == V2DImode || mode == V2DFmode)
817 
818 #endif /* GCC_AARCH64_H */
819