1 /* Definitions of target machine for Altera Nios II.
2 Copyright (C) 2012-2023 Free Software Foundation, Inc.
3 Contributed by Jonah Graham (jgraham@altera.com),
4 Will Reece (wreece@altera.com), and Jeff DaSilva (jdasilva@altera.com).
5 Contributed by Mentor Graphics, Inc.
6
7 This file is part of GCC.
8
9 GCC is free software; you can redistribute it and/or modify it
10 under the terms of the GNU General Public License as published
11 by the Free Software Foundation; either version 3, or (at your
12 option) any later version.
13
14 GCC is distributed in the hope that it will be useful, but WITHOUT
15 ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
16 or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public
17 License for more details.
18
19 You should have received a copy of the GNU General Public License
20 along with GCC; see the file COPYING3. If not see
21 <http://www.gnu.org/licenses/>. */
22
23 #ifndef GCC_NIOS2_H
24 #define GCC_NIOS2_H
25
26 /* Indicate R2 ISA level support. */
27 #define TARGET_ARCH_R2 (nios2_arch_option == ARCH_R2)
28
29 /* FPU insn codes declared here. */
30 #include "config/nios2/nios2-opts.h"
31
32 /* Define built-in preprocessor macros. */
33 #define TARGET_CPU_CPP_BUILTINS() \
34 do \
35 { \
36 builtin_define_std ("NIOS2"); \
37 builtin_define_std ("nios2"); \
38 if (TARGET_BIG_ENDIAN) \
39 builtin_define_std ("nios2_big_endian"); \
40 else \
41 builtin_define_std ("nios2_little_endian"); \
42 builtin_define_with_int_value ( \
43 "__nios2_arch__", (int) nios2_arch_option); \
44 } \
45 while (0)
46
47 /* We're little endian, unless otherwise specified by defining
48 BIG_ENDIAN_FLAG. */
49 #ifndef TARGET_ENDIAN_DEFAULT
50 # define TARGET_ENDIAN_DEFAULT 0
51 #endif
52
53 /* Default target_flags if no switches specified. */
54 #ifndef TARGET_DEFAULT
55 # define TARGET_DEFAULT (MASK_HAS_MUL | TARGET_ENDIAN_DEFAULT)
56 #endif
57
58 #define OPTION_DEFAULT_SPECS \
59 {"arch", "%{!march=*:%{!mcpu=*:-march=%(VALUE)}}" }
60
61 #define CC1_SPEC "%{G*}"
62
63 #if TARGET_ENDIAN_DEFAULT == 0
64 # define ASM_SPEC "%{!meb:-EL} %{meb:-EB} %{march=*:-march=%*}"
65 # define LINK_SPEC_ENDIAN "%{!meb:-EL} %{meb:-EB}"
66 # define MULTILIB_DEFAULTS { "EL" }
67 #else
68 # define ASM_SPEC "%{!mel:-EB} %{mel:-EL} %{march=*:-march=%*}"
69 # define LINK_SPEC_ENDIAN "%{!mel:-EB} %{mel:-EL}"
70 # define MULTILIB_DEFAULTS { "EB" }
71 #endif
72
73 #define LINK_SPEC LINK_SPEC_ENDIAN \
74 " %{shared:-shared} \
75 %{static:-Bstatic}"
76
77
78 /* Storage layout. */
79
80 #define DEFAULT_SIGNED_CHAR 1
81 #define BITS_BIG_ENDIAN 0
82 #define BYTES_BIG_ENDIAN (TARGET_BIG_ENDIAN != 0)
83 #define WORDS_BIG_ENDIAN (TARGET_BIG_ENDIAN != 0)
84 #define BITS_PER_WORD 32
85 #define UNITS_PER_WORD 4
86 #define POINTER_SIZE 32
87 #define BIGGEST_ALIGNMENT 32
88 #define STRICT_ALIGNMENT 1
89 #define FUNCTION_BOUNDARY 32
90 #define PARM_BOUNDARY 32
91 #define STACK_BOUNDARY 32
92 #define PREFERRED_STACK_BOUNDARY 32
93 #define MAX_FIXED_MODE_SIZE 64
94
95 #define LABEL_ALIGN(LABEL) nios2_label_align (LABEL)
96
97 /* Layout of source language data types. */
98
99 #define INT_TYPE_SIZE 32
100 #define SHORT_TYPE_SIZE 16
101 #define LONG_TYPE_SIZE 32
102 #define LONG_LONG_TYPE_SIZE 64
103 #define FLOAT_TYPE_SIZE 32
104 #define DOUBLE_TYPE_SIZE 64
105 #define LONG_DOUBLE_TYPE_SIZE DOUBLE_TYPE_SIZE
106
107 #undef SIZE_TYPE
108 #define SIZE_TYPE "unsigned int"
109
110 #undef PTRDIFF_TYPE
111 #define PTRDIFF_TYPE "int"
112
113
114 /* Basic characteristics of Nios II registers:
115
116 Regno Name
117 0 r0 zero always zero
118 1 r1 at Assembler Temporary
119 2-3 r2-r3 Return Location
120 4-7 r4-r7 Register Arguments
121 8-15 r8-r15 Caller Saved Registers
122 16-22 r16-r22 Callee Saved Registers
123 22 r22 Global Offset Table pointer (Linux ABI only)
124 23 r23 Thread pointer (Linux ABI only)
125 24 r24 et Exception Temporary
126 25 r25 bt Breakpoint Temporary
127 26 r26 gp Global Pointer
128 27 r27 sp Stack Pointer
129 28 r28 fp Frame Pointer
130 29 r29 ea Exception Return Address
131 30 r30 ba Breakpoint Return Address
132 31 r31 ra Return Address
133
134 32 ctl0 status
135 33 ctl1 estatus STATUS saved by exception
136 34 ctl2 bstatus STATUS saved by break
137 35 ctl3 ipri Interrupt Priority Mask
138 36 ctl4 ecause Exception Cause
139
140 37 pc Not an actual register
141
142 38 fake_fp Fake Frame Pointer (always eliminated)
143 39 fake_ap Fake Argument Pointer (always eliminated)
144 40 First Pseudo Register
145
146 In addition, r12 is used as the static chain register and r13, r14, and r15
147 are clobbered by PLT code sequences.
148
149 The definitions for all the hard register numbers are located in nios2.md.
150 */
151
152 #define FIXED_REGISTERS \
153 { \
154 /* +0 1 2 3 4 5 6 7 8 9 */ \
155 /* 0 */ 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, \
156 /* 10 */ 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, \
157 /* 20 */ 0, 0, TARGET_LINUX_ABI, TARGET_LINUX_ABI, 1, 1, 1, 1, 0, 1, \
158 /* 30 */ 1, 0, 1, 1, 1, 1, 1, 1, 1, 1, \
159 }
160
161 /* Call used == caller saved + fixed regs + args + ret vals. */
162 #define CALL_USED_REGISTERS \
163 { \
164 /* +0 1 2 3 4 5 6 7 8 9 */ \
165 /* 0 */ 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, \
166 /* 10 */ 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, \
167 /* 20 */ 0, 0, TARGET_LINUX_ABI, TARGET_LINUX_ABI, 1, 1, 1, 1, 0, 1, \
168 /* 30 */ 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, \
169 }
170
171 /* Order in which to allocate registers. Each register must be
172 listed once. This is the default ordering for R1 and non-CDX R2
173 code. For CDX, we overwrite this in ADJUST_REG_ALLOC_ORDER. */
174 #define REG_ALLOC_ORDER \
175 { 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, \
176 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, \
177 37, 38, 39 }
178
179 #define ADJUST_REG_ALLOC_ORDER nios2_adjust_reg_alloc_order ()
180
181 /* Caller-save costs can be less emphasized under R2 CDX, where we can
182 use push.n/pop.n. */
183 #define HONOR_REG_ALLOC_ORDER (TARGET_HAS_CDX)
184
185 /* Register Classes. */
186
187 enum reg_class
188 {
189 NO_REGS,
190 SIB_REGS,
191 IJMP_REGS,
192 GP_REGS,
193 ALL_REGS,
194 LIM_REG_CLASSES
195 };
196
197 #define N_REG_CLASSES (int) LIM_REG_CLASSES
198
199 #define REG_CLASS_NAMES \
200 { "NO_REGS", \
201 "SIB_REGS", \
202 "IJMP_REGS", \
203 "GP_REGS", \
204 "ALL_REGS" }
205
206 #define GENERAL_REGS ALL_REGS
207
208 #define REG_CLASS_CONTENTS \
209 { \
210 /* NO_REGS */ { 0, 0}, \
211 /* SIB_REGS */ { 0xfe0c, 0}, \
212 /* IJMP_REGS */ { 0x7fffffff, 0}, \
213 /* GP_REGS */ {~0, 0}, \
214 /* ALL_REGS */ {~0,~0} \
215 }
216
217
218 #define GP_REG_P(REGNO) ((unsigned)(REGNO) <= LAST_GP_REG)
219 #define REGNO_REG_CLASS(REGNO) (GP_REG_P (REGNO) ? GP_REGS : ALL_REGS)
220 #define CLASS_MAX_NREGS(CLASS, MODE) \
221 ((GET_MODE_SIZE (MODE) + UNITS_PER_WORD - 1) / UNITS_PER_WORD)
222
223 #define CDX_REG_P(REGNO) \
224 ((REGNO) == 16 || (REGNO) == 17 || ((REGNO) >= 2 && (REGNO) <= 7))
225
226 /* Tests for various kinds of constants used in the Nios II port. */
227
228 #define SMALL_INT(X) ((unsigned HOST_WIDE_INT)(X) + 0x8000 < 0x10000)
229 #define SMALL_INT12(X) ((unsigned HOST_WIDE_INT)(X) + 0x800 < 0x1000)
230 #define SMALL_INT_UNSIGNED(X) ((X) >= 0 && (X) < 0x10000)
231 #define UPPER16_INT(X) (((X) & 0xffff) == 0)
232 #define SHIFT_INT(X) ((X) >= 0 && (X) <= 31)
233 #define RDWRCTL_INT(X) ((X) >= 0 && (X) <= 31)
234 #define CUSTOM_INSN_OPCODE(X) ((X) >= 0 && (X) <= 255)
235 #define ANDCLEAR_INT(X) \
236 (((X) & 0xffff) == 0xffff || (((X) >> 16) & 0xffff) == 0xffff)
237
238 /* Say that the epilogue uses the return address register. Note that
239 in the case of sibcalls, the values "used by the epilogue" are
240 considered live at the start of the called function. */
241 #define EPILOGUE_USES(REGNO) (epilogue_completed && (REGNO) == RA_REGNO)
242
243 /* EXIT_IGNORE_STACK should be nonzero if, when returning from a function,
244 the stack pointer does not matter. The value is tested only in
245 functions that have frame pointers.
246 No definition is equivalent to always zero. */
247
248 #define EXIT_IGNORE_STACK 1
249
250 /* Trampolines use a 5-instruction sequence. */
251 #define TRAMPOLINE_SIZE 20
252
253 /* Stack layout. */
254 #define STACK_GROWS_DOWNWARD 1
255 #define FRAME_GROWS_DOWNWARD 1
256 #define FIRST_PARM_OFFSET(FUNDECL) 0
257
258 /* Before the prologue, RA lives in r31. */
259 #define INCOMING_RETURN_ADDR_RTX gen_rtx_REG (Pmode, RA_REGNO)
260 #define RETURN_ADDR_RTX(C,F) nios2_get_return_address (C)
261
262 #define DWARF_FRAME_RETURN_COLUMN RA_REGNO
263
264 /* The CFA includes the pretend args. */
265 #define ARG_POINTER_CFA_OFFSET(FNDECL) \
266 (gcc_assert ((FNDECL) == current_function_decl), \
267 FIRST_PARM_OFFSET (FNDECL) + crtl->args.pretend_args_size)
268
269 /* Frame/arg pointer elimination settings. */
270 #define ELIMINABLE_REGS \
271 {{ ARG_POINTER_REGNUM, STACK_POINTER_REGNUM}, \
272 { ARG_POINTER_REGNUM, HARD_FRAME_POINTER_REGNUM}, \
273 { FRAME_POINTER_REGNUM, STACK_POINTER_REGNUM}, \
274 { FRAME_POINTER_REGNUM, HARD_FRAME_POINTER_REGNUM}}
275
276 #define INITIAL_ELIMINATION_OFFSET(FROM, TO, OFFSET) \
277 (OFFSET) = nios2_initial_elimination_offset ((FROM), (TO))
278
279 /* Calling convention definitions. */
280 typedef struct nios2_args
281 {
282 int regs_used;
283 } CUMULATIVE_ARGS;
284
285 #define NUM_ARG_REGS (LAST_ARG_REGNO - FIRST_ARG_REGNO + 1)
286
287 #define INIT_CUMULATIVE_ARGS(CUM, FNTYPE, LIBNAME, FNDECL, N_NAMED_ARGS) \
288 do { (CUM).regs_used = 0; } while (0)
289
290 #define PAD_VARARGS_DOWN \
291 (targetm.calls.function_arg_padding (TYPE_MODE (type), type) == PAD_DOWNWARD)
292
293 #define BLOCK_REG_PADDING(MODE, TYPE, FIRST) \
294 (nios2_block_reg_padding ((MODE), (TYPE), (FIRST)))
295
296 #define FUNCTION_ARG_REGNO_P(REGNO) \
297 ((REGNO) >= FIRST_ARG_REGNO && (REGNO) <= LAST_ARG_REGNO)
298
299 /* Passing function arguments on stack. */
300 #define ACCUMULATE_OUTGOING_ARGS 1
301
302 /* We define TARGET_RETURN_IN_MEMORY, so set to zero. */
303 #define DEFAULT_PCC_STRUCT_RETURN 0
304
305 /* Profiling. */
306 #define PROFILE_BEFORE_PROLOGUE
307 #define NO_PROFILE_COUNTERS 1
308 #define FUNCTION_PROFILER(FILE, LABELNO) \
309 nios2_function_profiler ((FILE), (LABELNO))
310
311 /* Addressing modes. */
312
313 #define CONSTANT_ADDRESS_P(X) \
314 (CONSTANT_P (X) && memory_address_p (SImode, X))
315
316 #define MAX_REGS_PER_ADDRESS 1
317 #define BASE_REG_CLASS ALL_REGS
318 #define INDEX_REG_CLASS NO_REGS
319
320 #define REGNO_OK_FOR_BASE_P(REGNO) nios2_regno_ok_for_base_p ((REGNO), true)
321 #define REGNO_OK_FOR_INDEX_P(REGNO) 0
322
323 /* Describing Relative Costs of Operations. */
324 #define MOVE_MAX 4
325 #define SLOW_BYTE_ACCESS 1
326
327 /* It is as good to call a constant function address as to call an address
328 kept in a register. */
329 #define NO_FUNCTION_CSE 1
330
331 /* Position independent code. */
332
333 #define PIC_OFFSET_TABLE_REGNUM 22
334 #define LEGITIMATE_PIC_OPERAND_P(X) nios2_legitimate_pic_operand_p (X)
335
336 /* Define output assembler language. */
337
338 #define ASM_APP_ON "#APP\n"
339 #define ASM_APP_OFF "#NO_APP\n"
340
341 #define ASM_COMMENT_START "# "
342
343 #define GLOBAL_ASM_OP "\t.global\t"
344
345 #define REGISTER_NAMES \
346 { \
347 "zero", \
348 "at", \
349 "r2", \
350 "r3", \
351 "r4", \
352 "r5", \
353 "r6", \
354 "r7", \
355 "r8", \
356 "r9", \
357 "r10", \
358 "r11", \
359 "r12", \
360 "r13", \
361 "r14", \
362 "r15", \
363 "r16", \
364 "r17", \
365 "r18", \
366 "r19", \
367 "r20", \
368 "r21", \
369 "r22", \
370 "r23", \
371 "et", \
372 "bt", \
373 "gp", \
374 "sp", \
375 "fp", \
376 "ta", \
377 "ba", \
378 "ra", \
379 "status", \
380 "estatus", \
381 "bstatus", \
382 "ipri", \
383 "ecause", \
384 "pc", \
385 "fake_fp", \
386 "fake_ap", \
387 }
388
389 #define ADDITIONAL_REGISTER_NAMES \
390 { \
391 {"r0", 0}, \
392 {"r1", 1}, \
393 {"r24", 24}, \
394 {"r25", 25}, \
395 {"r26", 26}, \
396 {"r27", 27}, \
397 {"r28", 28}, \
398 {"r29", 29}, \
399 {"r30", 30}, \
400 {"r31", 31} \
401 }
402
403 #define ASM_OUTPUT_ADDR_VEC_ELT(FILE, VALUE) \
404 do \
405 { \
406 fputs (integer_asm_op (POINTER_SIZE / BITS_PER_UNIT, TRUE), FILE); \
407 fprintf (FILE, ".L%u\n", (unsigned) (VALUE)); \
408 } \
409 while (0)
410
411 #define ASM_OUTPUT_ADDR_DIFF_ELT(STREAM, BODY, VALUE, REL)\
412 do \
413 { \
414 fputs (integer_asm_op (POINTER_SIZE / BITS_PER_UNIT, TRUE), STREAM); \
415 fprintf (STREAM, ".L%u-.L%u\n", (unsigned) (VALUE), (unsigned) (REL)); \
416 } \
417 while (0)
418
419 /* Section directives. */
420
421 /* Output before read-only data. */
422 #define TEXT_SECTION_ASM_OP "\t.section\t.text"
423
424 /* Output before writable data. */
425 #define DATA_SECTION_ASM_OP "\t.section\t.data"
426
427 /* Output before uninitialized data. */
428 #define BSS_SECTION_ASM_OP "\t.section\t.bss"
429
430 /* Output before 'small' uninitialized data. */
431 #define SBSS_SECTION_ASM_OP "\t.section\t.sbss"
432
433 #ifndef USED_FOR_TARGET
434 /* Default the definition of "small data" to 8 bytes. */
435 extern unsigned HOST_WIDE_INT nios2_section_threshold;
436 #endif
437
438 #define NIOS2_DEFAULT_GVALUE 8
439
440 /* This says how to output assembler code to declare an
441 uninitialized external linkage data object. Under SVR4,
442 the linker seems to want the alignment of data objects
443 to depend on their types. We do exactly that here. */
444 #undef COMMON_ASM_OP
445 #define COMMON_ASM_OP "\t.comm\t"
446
447 #define ASM_OUTPUT_ALIGN(FILE, LOG) \
448 do { \
449 fprintf ((FILE), "%s%d\n", ALIGN_ASM_OP, (LOG)); \
450 } while (0)
451
452 #undef ASM_OUTPUT_ALIGNED_COMMON
453 #define ASM_OUTPUT_ALIGNED_COMMON(FILE, NAME, SIZE, ALIGN) \
454 do \
455 { \
456 fprintf ((FILE), "%s", COMMON_ASM_OP); \
457 assemble_name ((FILE), (NAME)); \
458 fprintf ((FILE), "," HOST_WIDE_INT_PRINT_UNSIGNED",%u\n", (SIZE), \
459 (ALIGN) / BITS_PER_UNIT); \
460 } \
461 while (0)
462
463
464 /* This says how to output assembler code to declare an
465 uninitialized internal linkage data object. Under SVR4,
466 the linker seems to want the alignment of data objects
467 to depend on their types. We do exactly that here. */
468
469 #undef ASM_OUTPUT_ALIGNED_DECL_LOCAL
470 #define ASM_OUTPUT_ALIGNED_DECL_LOCAL(FILE, DECL, NAME, SIZE, ALIGN) \
471 do { \
472 if (targetm.in_small_data_p (DECL)) \
473 switch_to_section (sbss_section); \
474 else \
475 switch_to_section (bss_section); \
476 ASM_OUTPUT_TYPE_DIRECTIVE (FILE, NAME, "object"); \
477 if (!flag_inhibit_size_directive) \
478 ASM_OUTPUT_SIZE_DIRECTIVE (FILE, NAME, SIZE); \
479 ASM_OUTPUT_ALIGN ((FILE), exact_log2((ALIGN) / BITS_PER_UNIT)); \
480 ASM_OUTPUT_LABEL(FILE, NAME); \
481 ASM_OUTPUT_SKIP((FILE), (SIZE) ? (SIZE) : 1); \
482 } while (0)
483
484 /* Put the jump tables in .text because when using position-independent code,
485 Nios II elf has no relocation that can represent arbitrary differences
486 between symbols in different sections. */
487 #define JUMP_TABLES_IN_TEXT_SECTION 1
488
489 /* Exception handling. */
490
491 /* Describe __builtin_eh_return. */
492 #define EH_RETURN_STACKADJ_RTX gen_rtx_REG (Pmode, LAST_RETVAL_REGNO)
493 #define EH_RETURN_DATA_REGNO(N) ((N) <= (LAST_ARG_REGNO - FIRST_ARG_REGNO) \
494 ? (N) + FIRST_ARG_REGNO : INVALID_REGNUM)
495
496 /* For PIC, use indirect for global references; it'll end up using a dynamic
497 relocation, which we want to keep out of read-only EH sections.
498 For local references, we want to use GOT-relative offsets provided
499 the assembler supports them. For non-PIC, use an absolute encoding. */
500 #ifdef HAVE_AS_NIOS2_GOTOFF_RELOCATION
501 #define ASM_PREFERRED_EH_DATA_FORMAT(CODE, GLOBAL) \
502 (flag_pic \
503 ? ((GLOBAL) \
504 ? DW_EH_PE_indirect | DW_EH_PE_absptr \
505 : DW_EH_PE_datarel | DW_EH_PE_sdata4) \
506 : DW_EH_PE_absptr)
507
508 #define ASM_MAYBE_OUTPUT_ENCODED_ADDR_RTX(FILE, ENCODING, SIZE, ADDR, DONE) \
509 do { \
510 if (((ENCODING) & 0xf0) == DW_EH_PE_datarel) \
511 { \
512 fputs ("\t.4byte %gotoff(", FILE); \
513 output_addr_const (FILE, ADDR); \
514 fputs (")", FILE); \
515 goto DONE; \
516 } \
517 } while (0)
518
519 #else
520 /* We don't have %gotoff support in the assembler. Fall back to the encoding
521 it used to use instead before the assembler was fixed. This has known
522 bugs but mostly works. */
523 #define ASM_PREFERRED_EH_DATA_FORMAT(CODE, GLOBAL) \
524 (flag_pic \
525 ? ((GLOBAL) \
526 ? DW_EH_PE_indirect | DW_EH_PE_absptr \
527 : DW_EH_PE_aligned) \
528 : DW_EH_PE_absptr)
529 #endif
530
531 /* Misc. parameters. */
532
533 #define STORE_FLAG_VALUE 1
534 #define Pmode SImode
535 #define FUNCTION_MODE QImode
536
537 #define CASE_VECTOR_MODE Pmode
538
539 #define LOAD_EXTEND_OP(MODE) (ZERO_EXTEND)
540
541 #define WORD_REGISTER_OPERATIONS 1
542
543 #endif /* GCC_NIOS2_H */