1/* Definitions of target machine for GNU compiler,
2   for ATMEL AVR at90s8515, ATmega103/103L, ATmega603/603L microcontrollers.
3   Copyright (C) 1998-2022 Free Software Foundation, Inc.
4   Contributed by Denis Chertykov (chertykov@gmail.com)
5
6This file is part of GCC.
7
8GCC is free software; you can redistribute it and/or modify
9it under the terms of the GNU General Public License as published by
10the Free Software Foundation; either version 3, or (at your option)
11any later version.
12
13GCC is distributed in the hope that it will be useful,
14but WITHOUT ANY WARRANTY; without even the implied warranty of
15MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
16GNU General Public License for more details.
17
18You should have received a copy of the GNU General Public License
19along with GCC; see the file COPYING3.  If not see
20<http://www.gnu.org/licenses/>.  */
21
22typedef struct
23{
24  /* Id of the address space as used in c_register_addr_space */
25  unsigned char id;
26
27  /* Flavour of memory: 0 = RAM, 1 = Flash */
28  int memory_class;
29
30  /* Width of pointer (in bytes) */
31  int pointer_size;
32
33  /* Name of the address space as visible to the user */
34  const char *name;
35
36  /* Segment (i.e. 64k memory chunk) number.  */
37  int segment;
38
39  /* Section prefix, e.g. ".progmem1.data"  */
40  const char *section_name;
41} avr_addrspace_t;
42
43extern const avr_addrspace_t avr_addrspace[];
44
45/* Known address spaces */
46
47enum
48  {
49    ADDR_SPACE_RAM, /* ADDR_SPACE_GENERIC */
50    ADDR_SPACE_FLASH,
51    ADDR_SPACE_FLASH1,
52    ADDR_SPACE_FLASH2,
53    ADDR_SPACE_FLASH3,
54    ADDR_SPACE_FLASH4,
55    ADDR_SPACE_FLASH5,
56    ADDR_SPACE_MEMX,
57    /* Sentinel */
58    ADDR_SPACE_COUNT
59  };
60
61#define TARGET_CPU_CPP_BUILTINS()	avr_cpu_cpp_builtins (pfile)
62
63#define AVR_SHORT_CALLS (TARGET_SHORT_CALLS                             \
64                         && avr_arch == &avr_arch_types[ARCH_AVRXMEGA3])
65#define AVR_HAVE_JMP_CALL (avr_arch->have_jmp_call && ! AVR_SHORT_CALLS)
66#define AVR_HAVE_MUL (avr_arch->have_mul)
67#define AVR_HAVE_MOVW (avr_arch->have_movw_lpmx)
68#define AVR_HAVE_LPM (!AVR_TINY)
69#define AVR_HAVE_LPMX (avr_arch->have_movw_lpmx)
70#define AVR_HAVE_ELPM (avr_arch->have_elpm)
71#define AVR_HAVE_ELPMX (avr_arch->have_elpmx)
72#define AVR_HAVE_RAMPD (avr_arch->have_rampd)
73#define AVR_HAVE_RAMPX (avr_arch->have_rampd)
74#define AVR_HAVE_RAMPY (avr_arch->have_rampd)
75#define AVR_HAVE_RAMPZ (avr_arch->have_elpm             \
76                        || avr_arch->have_rampd)
77#define AVR_HAVE_EIJMP_EICALL (avr_arch->have_eijmp_eicall)
78
79/* Handling of 8-bit SP versus 16-bit SP is as follows:
80
81FIXME: DRIVER_SELF_SPECS has changed.
82   -msp8 is used internally to select the right multilib for targets with
83   8-bit SP.  -msp8 is set automatically by DRIVER_SELF_SPECS for devices
84   with 8-bit SP or by multilib generation machinery.  If a frame pointer is
85   needed and SP is only 8 bits wide, SP is zero-extended to get FP.
86
87   TARGET_TINY_STACK is triggered by -mtiny-stack which is a user option.
88   This option has no effect on multilib selection.  It serves to save some
89   bytes on 16-bit SP devices by only changing SP_L and leaving SP_H alone.
90
91   These two properties are reflected by built-in macros __AVR_SP8__ resp.
92   __AVR_HAVE_8BIT_SP__ and __AVR_HAVE_16BIT_SP__.  During multilib generation
93   there is always __AVR_SP8__ == __AVR_HAVE_8BIT_SP__.  */
94
95#define AVR_HAVE_8BIT_SP                        \
96  (TARGET_TINY_STACK || avr_sp8)
97
98#define AVR_HAVE_SPH (!avr_sp8)
99
100#define AVR_2_BYTE_PC (!AVR_HAVE_EIJMP_EICALL)
101#define AVR_3_BYTE_PC (AVR_HAVE_EIJMP_EICALL)
102
103#define AVR_XMEGA (avr_arch->xmega_p)
104#define AVR_TINY  (avr_arch->tiny_p)
105
106#define BITS_BIG_ENDIAN 0
107#define BYTES_BIG_ENDIAN 0
108#define WORDS_BIG_ENDIAN 0
109
110#define FLOAT_LIB_COMPARE_RETURNS_BOOL(mode, comparison) \
111  avr_float_lib_compare_returns_bool (mode, comparison)
112
113#ifdef IN_LIBGCC2
114/* This is to get correct SI and DI modes in libgcc2.c (32 and 64 bits).  */
115#define UNITS_PER_WORD 4
116#else
117/* Width of a word, in units (bytes).  */
118#define UNITS_PER_WORD 1
119#endif
120
121#define POINTER_SIZE 16
122
123
124/* Maximum sized of reasonable data type
125   DImode or Dfmode ...  */
126#define MAX_FIXED_MODE_SIZE 32
127
128#define PARM_BOUNDARY 8
129
130#define FUNCTION_BOUNDARY 8
131
132#define EMPTY_FIELD_BOUNDARY 8
133
134/* No data type wants to be aligned rounder than this.  */
135#define BIGGEST_ALIGNMENT 8
136
137#define TARGET_VTABLE_ENTRY_ALIGN 8
138
139#define STRICT_ALIGNMENT 0
140
141#define INT_TYPE_SIZE (TARGET_INT8 ? 8 : 16)
142#define SHORT_TYPE_SIZE (INT_TYPE_SIZE == 8 ? INT_TYPE_SIZE : 16)
143#define LONG_TYPE_SIZE (INT_TYPE_SIZE == 8 ? 16 : 32)
144#define LONG_LONG_TYPE_SIZE (INT_TYPE_SIZE == 8 ? 32 : 64)
145#define FLOAT_TYPE_SIZE 32
146#define DOUBLE_TYPE_SIZE (avr_double)
147#define LONG_DOUBLE_TYPE_SIZE (avr_long_double)
148
149#define LONG_LONG_ACCUM_TYPE_SIZE 64
150
151#define DEFAULT_SIGNED_CHAR 1
152
153#define SIZE_TYPE (INT_TYPE_SIZE == 8 ? "long unsigned int" : "unsigned int")
154#define PTRDIFF_TYPE (INT_TYPE_SIZE == 8 ? "long int" :"int")
155
156#define WCHAR_TYPE_SIZE 16
157
158#define FIRST_PSEUDO_REGISTER 37
159
160#define GENERAL_REGNO_P(N)	IN_RANGE (N, 2, 31)
161#define GENERAL_REG_P(X)	(REG_P (X) && GENERAL_REGNO_P (REGNO (X)))
162
163#define FIXED_REGISTERS {\
164  1,1,/* r0 r1 */\
165  0,0,/* r2 r3 */\
166  0,0,/* r4 r5 */\
167  0,0,/* r6 r7 */\
168  0,0,/* r8 r9 */\
169  0,0,/* r10 r11 */\
170  0,0,/* r12 r13 */\
171  0,0,/* r14 r15 */\
172  0,0,/* r16 r17 */\
173  0,0,/* r18 r19 */\
174  0,0,/* r20 r21 */\
175  0,0,/* r22 r23 */\
176  0,0,/* r24 r25 */\
177  0,0,/* r26 r27 */\
178  0,0,/* r28 r29 */\
179  0,0,/* r30 r31 */\
180  1,1,/*  STACK */\
181  1,1, /* arg pointer */						\
182  1 /* CC */ }
183
184#define CALL_USED_REGISTERS {			\
185  1,1,/* r0 r1 */				\
186    0,0,/* r2 r3 */				\
187    0,0,/* r4 r5 */				\
188    0,0,/* r6 r7 */				\
189    0,0,/* r8 r9 */				\
190    0,0,/* r10 r11 */				\
191    0,0,/* r12 r13 */				\
192    0,0,/* r14 r15 */				\
193    0,0,/* r16 r17 */				\
194    1,1,/* r18 r19 */				\
195    1,1,/* r20 r21 */				\
196    1,1,/* r22 r23 */				\
197    1,1,/* r24 r25 */				\
198    1,1,/* r26 r27 */				\
199    0,0,/* r28 r29 */				\
200    1,1,/* r30 r31 */				\
201    1,1,/*  STACK */				\
202    1,1, /* arg pointer */			\
203    1 /* CC */ }
204
205#define REG_ALLOC_ORDER {			\
206    24,25,					\
207    18,19,					\
208    20,21,					\
209    22,23,					\
210    30,31,					\
211    26,27,					\
212    28,29,					\
213    17,16,15,14,13,12,11,10,9,8,7,6,5,4,3,2,	\
214    0,1,					\
215    32,33,34,35,36			\
216    }
217
218#define ADJUST_REG_ALLOC_ORDER avr_adjust_reg_alloc_order()
219
220
221enum reg_class {
222  NO_REGS,
223  R0_REG,			/* r0 */
224  POINTER_X_REGS,		/* r26 - r27 */
225  POINTER_Y_REGS,		/* r28 - r29 */
226  POINTER_Z_REGS,		/* r30 - r31 */
227  STACK_REG,			/* STACK */
228  BASE_POINTER_REGS,		/* r28 - r31 */
229  POINTER_REGS,			/* r26 - r31 */
230  ADDW_REGS,			/* r24 - r31 */
231  SIMPLE_LD_REGS,		/* r16 - r23 */
232  LD_REGS,			/* r16 - r31 */
233  NO_LD_REGS,			/* r0 - r15 */
234  GENERAL_REGS,			/* r0 - r31 */
235  CC_REG,			/* CC */
236  ALL_REGS, LIM_REG_CLASSES
237};
238
239
240#define N_REG_CLASSES (int)LIM_REG_CLASSES
241
242#define REG_CLASS_NAMES {					\
243		 "NO_REGS",					\
244		   "R0_REG",	/* r0 */                        \
245		   "POINTER_X_REGS", /* r26 - r27 */		\
246		   "POINTER_Y_REGS", /* r28 - r29 */		\
247		   "POINTER_Z_REGS", /* r30 - r31 */		\
248		   "STACK_REG",	/* STACK */			\
249		   "BASE_POINTER_REGS",	/* r28 - r31 */		\
250		   "POINTER_REGS", /* r26 - r31 */		\
251		   "ADDW_REGS",	/* r24 - r31 */			\
252                   "SIMPLE_LD_REGS", /* r16 - r23 */            \
253		   "LD_REGS",	/* r16 - r31 */			\
254                   "NO_LD_REGS", /* r0 - r15 */                 \
255		   "GENERAL_REGS", /* r0 - r31 */		\
256		   "CC_REG", /* CC */		\
257		   "ALL_REGS" }
258
259#define REG_CLASS_CONTENTS {						\
260  {0x00000000,0x00000000},	/* NO_REGS */				\
261  {0x00000001,0x00000000},	/* R0_REG */                            \
262  {3u << REG_X,0x00000000},     /* POINTER_X_REGS, r26 - r27 */		\
263  {3u << REG_Y,0x00000000},     /* POINTER_Y_REGS, r28 - r29 */		\
264  {3u << REG_Z,0x00000000},     /* POINTER_Z_REGS, r30 - r31 */		\
265  {0x00000000,0x00000003},	/* STACK_REG, STACK */			\
266  {(3u << REG_Y) | (3u << REG_Z),					\
267     0x00000000},		/* BASE_POINTER_REGS, r28 - r31 */	\
268  {(3u << REG_X) | (3u << REG_Y) | (3u << REG_Z),			\
269     0x00000000},		/* POINTER_REGS, r26 - r31 */		\
270  {(3u << REG_X) | (3u << REG_Y) | (3u << REG_Z) | (3u << REG_W),	\
271     0x00000000},		/* ADDW_REGS, r24 - r31 */		\
272  {0x00ff0000,0x00000000},	/* SIMPLE_LD_REGS r16 - r23 */          \
273  {(3u << REG_X)|(3u << REG_Y)|(3u << REG_Z)|(3u << REG_W)|(0xffu << 16),\
274     0x00000000},	/* LD_REGS, r16 - r31 */			\
275  {0x0000ffff,0x00000000},	/* NO_LD_REGS  r0 - r15 */              \
276  {0xffffffff,0x00000000},	/* GENERAL_REGS, r0 - r31 */		\
277  {0x00000000,0x00000010},	/* CC */				\
278  {0xffffffff,0x00000013}	/* ALL_REGS */				\
279}
280
281#define REGNO_REG_CLASS(R) avr_regno_reg_class(R)
282
283#define MODE_CODE_BASE_REG_CLASS(mode, as, outer_code, index_code)   \
284  avr_mode_code_base_reg_class (mode, as, outer_code, index_code)
285
286#define INDEX_REG_CLASS NO_REGS
287
288#define REGNO_MODE_CODE_OK_FOR_BASE_P(num, mode, as, outer_code, index_code) \
289  avr_regno_mode_code_ok_for_base_p (num, mode, as, outer_code, index_code)
290
291#define REGNO_OK_FOR_INDEX_P(NUM) 0
292
293#define TARGET_SMALL_REGISTER_CLASSES_FOR_MODE_P hook_bool_mode_true
294
295#define STACK_PUSH_CODE POST_DEC
296
297#define STACK_GROWS_DOWNWARD 1
298
299#define STACK_POINTER_OFFSET 1
300
301#define FIRST_PARM_OFFSET(FUNDECL) 0
302
303#define STACK_BOUNDARY 8
304
305#define STACK_POINTER_REGNUM 32
306
307#define FRAME_POINTER_REGNUM REG_Y
308
309#define ARG_POINTER_REGNUM 34
310
311#define STATIC_CHAIN_REGNUM ((AVR_TINY) ? 18 :2)
312
313#define ELIMINABLE_REGS {					\
314    { ARG_POINTER_REGNUM, STACK_POINTER_REGNUM },               \
315    { ARG_POINTER_REGNUM, FRAME_POINTER_REGNUM },               \
316    { FRAME_POINTER_REGNUM, STACK_POINTER_REGNUM },             \
317    { FRAME_POINTER_REGNUM + 1, STACK_POINTER_REGNUM + 1 } }
318
319#define INITIAL_ELIMINATION_OFFSET(FROM, TO, OFFSET)			\
320  OFFSET = avr_initial_elimination_offset (FROM, TO)
321
322#define RETURN_ADDR_RTX(count, tem) avr_return_addr_rtx (count, tem)
323
324/* Don't use Push rounding. expr.cc: emit_single_push_insn is broken
325   for POST_DEC targets (PR27386).  */
326/*#define PUSH_ROUNDING(NPUSHED) (NPUSHED)*/
327
328typedef struct avr_args
329{
330  /* # Registers available for passing */
331  int nregs;
332
333  /* Next available register number */
334  int regno;
335} CUMULATIVE_ARGS;
336
337#define INIT_CUMULATIVE_ARGS(CUM, FNTYPE, LIBNAME, FNDECL, N_NAMED_ARGS) \
338  avr_init_cumulative_args (&(CUM), FNTYPE, LIBNAME, FNDECL)
339
340#define FUNCTION_ARG_REGNO_P(r) avr_function_arg_regno_p(r)
341
342#define DEFAULT_PCC_STRUCT_RETURN 0
343
344#define EPILOGUE_USES(REGNO) avr_epilogue_uses(REGNO)
345
346#define HAVE_POST_INCREMENT 1
347#define HAVE_PRE_DECREMENT 1
348
349#define MAX_REGS_PER_ADDRESS 1
350
351#define LEGITIMIZE_RELOAD_ADDRESS(X,MODE,OPNUM,TYPE,IND_L,WIN)          \
352  do {                                                                  \
353    rtx new_x = avr_legitimize_reload_address (&(X), MODE, OPNUM, TYPE, \
354                                               ADDR_TYPE (TYPE),        \
355                                               IND_L, make_memloc);     \
356    if (new_x)                                                          \
357      {                                                                 \
358        X = new_x;                                                      \
359        goto WIN;                                                       \
360      }                                                                 \
361  } while (0)
362
363/* We increase branch costs after reload in order to keep basic-block
364   reordering from introducing out-of-line jumps and to prefer fall-through
365   edges instead.  The default branch costs are 0, mainly because otherwise
366   do_store_flag might come up with bloated code.  */
367#define BRANCH_COST(speed_p, predictable_p)     \
368  (avr_branch_cost + (reload_completed ? 4 : 0))
369
370#define SLOW_BYTE_ACCESS 0
371
372#define NO_FUNCTION_CSE 1
373
374#define REGISTER_TARGET_PRAGMAS()                                       \
375  do {                                                                  \
376    avr_register_target_pragmas();                                      \
377  } while (0)
378
379#define TEXT_SECTION_ASM_OP "\t.text"
380
381#define DATA_SECTION_ASM_OP "\t.data"
382
383#define BSS_SECTION_ASM_OP "\t.section .bss"
384
385/* Define the pseudo-ops used to switch to the .ctors and .dtors sections.
386   There are no shared libraries on this target, and these sections are
387   placed in the read-only program memory, so they are not writable.  */
388
389#undef CTORS_SECTION_ASM_OP
390#define CTORS_SECTION_ASM_OP "\t.section .ctors,\"a\",@progbits"
391
392#undef DTORS_SECTION_ASM_OP
393#define DTORS_SECTION_ASM_OP "\t.section .dtors,\"a\",@progbits"
394
395#define TARGET_ASM_CONSTRUCTOR avr_asm_out_ctor
396
397#define TARGET_ASM_DESTRUCTOR avr_asm_out_dtor
398
399#define SUPPORTS_INIT_PRIORITY 0
400
401/* We pretend jump tables are in text section because otherwise,
402   final.cc will switch to .rodata before jump tables and thereby
403   triggers __do_copy_data.  As we implement ASM_OUTPUT_ADDR_VEC,
404   we still have full control over the jump tables themselves.  */
405#define JUMP_TABLES_IN_TEXT_SECTION 1
406
407#define ASM_COMMENT_START " ; "
408
409#define ASM_APP_ON "/* #APP */\n"
410
411#define ASM_APP_OFF "/* #NOAPP */\n"
412
413#define IS_ASM_LOGICAL_LINE_SEPARATOR(C, STR) ((C) == '\n' || ((C) == '$'))
414
415#define ASM_OUTPUT_ALIGNED_DECL_COMMON(STREAM, DECL, NAME, SIZE, ALIGN) \
416  avr_asm_output_aligned_decl_common (STREAM, DECL, NAME, SIZE, ALIGN, false)
417
418#define ASM_OUTPUT_ALIGNED_BSS(FILE, DECL, NAME, SIZE, ALIGN) \
419  avr_asm_asm_output_aligned_bss (FILE, DECL, NAME, SIZE, ALIGN, \
420				  asm_output_aligned_bss)
421
422#define ASM_OUTPUT_ALIGNED_DECL_LOCAL(STREAM, DECL, NAME, SIZE, ALIGN)  \
423  avr_asm_output_aligned_decl_common (STREAM, DECL, NAME, SIZE, ALIGN, true)
424
425/* Globalizing directive for a label.  */
426#define GLOBAL_ASM_OP ".global\t"
427
428#define SUPPORTS_WEAK 1
429
430#define HAS_INIT_SECTION 1
431
432#define REGISTER_NAMES {				\
433  "r0","r1","r2","r3","r4","r5","r6","r7",		\
434    "r8","r9","r10","r11","r12","r13","r14","r15",	\
435    "r16","r17","r18","r19","r20","r21","r22","r23",	\
436    "r24","r25","r26","r27","r28","r29","r30","r31",	\
437    "__SP_L__","__SP_H__","argL","argH", "cc"}
438
439#define FINAL_PRESCAN_INSN(insn, operand, nop)  \
440  avr_final_prescan_insn (insn, operand,nop)
441
442#define ASM_OUTPUT_REG_PUSH(STREAM, REGNO)	\
443{						\
444  gcc_assert (REGNO < 32);			\
445  fprintf (STREAM, "\tpush\tr%d", REGNO);	\
446}
447
448#define ASM_OUTPUT_REG_POP(STREAM, REGNO)	\
449{						\
450  gcc_assert (REGNO < 32);			\
451  fprintf (STREAM, "\tpop\tr%d", REGNO);	\
452}
453
454#define ASM_OUTPUT_ADDR_VEC(TLABEL, TDATA)      \
455  avr_output_addr_vec (TLABEL, TDATA)
456
457#define ASM_OUTPUT_ALIGN(STREAM, POWER)                 \
458  do {                                                  \
459    if ((POWER) > 0)                                    \
460      fprintf (STREAM, "\t.p2align\t%d\n", POWER);      \
461  } while (0)
462
463#define CASE_VECTOR_MODE HImode
464
465#undef WORD_REGISTER_OPERATIONS
466
467/* Can move only a single byte from memory to reg in a
468   single instruction. */
469
470#define MOVE_MAX 1
471
472/* Allow upto two bytes moves to occur using by_pieces
473   infrastructure */
474
475#define MOVE_MAX_PIECES 2
476
477/* Set MOVE_RATIO to 3 to allow memory moves upto 4 bytes to happen
478   by pieces when optimizing for speed, like it did when MOVE_MAX_PIECES
479   was 4. When optimizing for size, allow memory moves upto 2 bytes.
480   Also see avr_use_by_pieces_infrastructure_p. */
481
482#define MOVE_RATIO(speed) ((speed) ? 3 : 2)
483
484#define Pmode HImode
485
486#define FUNCTION_MODE HImode
487
488#define DOLLARS_IN_IDENTIFIERS 0
489
490#define TRAMPOLINE_SIZE 4
491
492/* Output assembler code to FILE to increment profiler label # LABELNO
493   for profiling a function entry.  */
494
495#define FUNCTION_PROFILER(FILE, LABELNO)  \
496  fprintf (FILE, "/* profiler %d */", (LABELNO))
497
498#define ADJUST_INSN_LENGTH(INSN, LENGTH)                \
499    (LENGTH = avr_adjust_insn_length (INSN, LENGTH))
500
501extern const char *avr_devicespecs_file (int, const char**);
502extern const char *avr_double_lib (int, const char**);
503
504#define EXTRA_SPEC_FUNCTIONS                            \
505  { "double-lib", avr_double_lib },                     \
506  { "device-specs-file", avr_devicespecs_file },
507
508/* Driver self specs has lmited functionality w.r.t. '%s' for dynamic specs.
509   Apply '%s' to a static string to inflate the file (directory) name which
510   is used to diagnose problems with reading the specs file.  */
511
512#undef  DRIVER_SELF_SPECS
513#define DRIVER_SELF_SPECS                               \
514  " %:double-lib(%{m*:m%*})"                            \
515  " %:device-specs-file(device-specs%s %{mmcu=*:%*})"
516
517/* No libstdc++ for now.  Empty string doesn't work.  */
518#define LIBSTDCXX "gcc"
519
520/* This is the default without any -mmcu=* option.  */
521#define MULTILIB_DEFAULTS { "mmcu=" AVR_MMCU_DEFAULT }
522
523#define TEST_HARD_REG_CLASS(CLASS, REGNO) \
524  TEST_HARD_REG_BIT (reg_class_contents[ (int) (CLASS)], REGNO)
525
526#define CR_TAB "\n\t"
527
528#define DWARF2_ADDR_SIZE 4
529
530#define INCOMING_RETURN_ADDR_RTX   avr_incoming_return_addr_rtx ()
531#define INCOMING_FRAME_SP_OFFSET   (AVR_3_BYTE_PC ? 3 : 2)
532
533/* The caller's stack pointer value immediately before the call
534   is one byte below the first argument.  */
535#define ARG_POINTER_CFA_OFFSET(FNDECL)  -1
536
537#define HARD_REGNO_RENAME_OK(OLD_REG, NEW_REG) \
538  avr_hard_regno_rename_ok (OLD_REG, NEW_REG)
539
540/* A C structure for machine-specific, per-function data.
541   This is added to the cfun structure.  */
542struct GTY(()) machine_function
543{
544  /* 'true' - if current function is a naked function.  */
545  int is_naked;
546
547  /* 'true' - if current function is an interrupt function
548     as specified by the "interrupt" attribute.  */
549  int is_interrupt;
550
551  /* 'true' - if current function is a signal function
552     as specified by the "signal" attribute.  */
553  int is_signal;
554
555  /* 'true' - if current function is a 'task' function
556     as specified by the "OS_task" attribute.  */
557  int is_OS_task;
558
559  /* 'true' - if current function is a 'main' function
560     as specified by the "OS_main" attribute.  */
561  int is_OS_main;
562
563  /* Current function stack size.  */
564  int stack_usage;
565
566  /* 'true' if a callee might be tail called */
567  int sibcall_fails;
568
569  /* 'true' if the above is_foo predicates are sanity-checked to avoid
570     multiple diagnose for the same function.  */
571  int attributes_checked_p;
572
573  /* 'true' - if current function shall not use '__gcc_isr' pseudo
574     instructions as specified by the "no_gccisr" attribute.  */
575  int is_no_gccisr;
576
577  /* Used for `__gcc_isr' pseudo instruction handling of
578     non-naked ISR prologue / epilogue(s).  */
579  struct
580  {
581    /* 'true' if this function actually uses "*gasisr" insns. */
582    int yes;
583    /* 'true' if this function is allowed to use "*gasisr" insns. */
584    int maybe;
585    /* The register numer as printed by the Done chunk.  */
586    int regno;
587  } gasisr;
588
589  /* 'true' if this function references .L__stack_usage like with
590     __builtin_return_address.  */
591  int use_L__stack_usage;
592};
593
594/* AVR does not round pushes, but the existence of this macro is
595   required in order for pushes to be generated.  */
596#define PUSH_ROUNDING(X)	(X)
597
598/* Define prototype here to avoid build warning.  Some files using
599   ACCUMULATE_OUTGOING_ARGS (directly or indirectly) include
600   tm.h but not tm_p.h.  */
601extern int avr_accumulate_outgoing_args (void);
602#define ACCUMULATE_OUTGOING_ARGS avr_accumulate_outgoing_args()
603
604#define INIT_EXPANDERS avr_init_expanders()
605
606/* Flags used for io and address attributes.  */
607#define SYMBOL_FLAG_IO_LOW	(SYMBOL_FLAG_MACH_DEP << 4)
608#define SYMBOL_FLAG_IO		(SYMBOL_FLAG_MACH_DEP << 5)
609#define SYMBOL_FLAG_ADDRESS	(SYMBOL_FLAG_MACH_DEP << 6)
610