1 /* Definitions of Tensilica's Xtensa target machine for GNU compiler.
2 Copyright (C) 2001 Free Software Foundation, Inc.
3 Contributed by Bob Wilson (bwilson@tensilica.com) at Tensilica.
5 This file is part of GCC.
7 GCC is free software; you can redistribute it and/or modify it under
8 the terms of the GNU General Public License as published by the Free
9 Software Foundation; either version 2, or (at your option) any later
12 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
13 WARRANTY; without even the implied warranty of MERCHANTABILITY or
14 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
17 You should have received a copy of the GNU General Public License
18 along with GCC; see the file COPYING. If not, write to the Free
19 Software Foundation, 59 Temple Place - Suite 330, Boston, MA
22 /* Get Xtensa configuration settings */
23 #include "xtensa/xtensa-config.h"
25 /* Standard GCC variables that we reference. */
26 extern int current_function_calls_alloca;
27 extern int target_flags;
30 /* External variables defined in xtensa.c. */
34 CMP_SI, /* four byte integers */
35 CMP_DI, /* eight byte integers */
36 CMP_SF, /* single precision floats */
37 CMP_DF, /* double precision floats */
38 CMP_MAX /* max comparison type */
41 extern struct rtx_def * branch_cmp[2]; /* operands for compare */
42 extern enum cmp_type branch_type; /* what type of branch to use */
43 extern unsigned xtensa_current_frame_size;
45 /* Run-time compilation parameters selecting different hardware subsets. */
47 #define MASK_BIG_ENDIAN 0x00000001 /* big or little endian */
48 #define MASK_DENSITY 0x00000002 /* code density option */
49 #define MASK_MAC16 0x00000004 /* MAC16 option */
50 #define MASK_MUL16 0x00000008 /* 16-bit integer multiply */
51 #define MASK_MUL32 0x00000010 /* integer multiply/divide */
52 #define MASK_DIV32 0x00000020 /* integer multiply/divide */
53 #define MASK_NSA 0x00000040 /* nsa instruction option */
54 #define MASK_MINMAX 0x00000080 /* min/max instructions */
55 #define MASK_SEXT 0x00000100 /* sign extend insn option */
56 #define MASK_BOOLEANS 0x00000200 /* boolean register option */
57 #define MASK_HARD_FLOAT 0x00000400 /* floating-point option */
58 #define MASK_HARD_FLOAT_DIV 0x00000800 /* floating-point divide */
59 #define MASK_HARD_FLOAT_RECIP 0x00001000 /* floating-point reciprocal */
60 #define MASK_HARD_FLOAT_SQRT 0x00002000 /* floating-point sqrt */
61 #define MASK_HARD_FLOAT_RSQRT 0x00004000 /* floating-point recip sqrt */
62 #define MASK_NO_FUSED_MADD 0x00008000 /* avoid f-p mul/add */
63 #define MASK_SERIALIZE_VOLATILE 0x00010000 /* serialize volatile refs */
65 /* Macros used in the machine description to test the flags. */
67 #define TARGET_BIG_ENDIAN (target_flags & MASK_BIG_ENDIAN)
68 #define TARGET_DENSITY (target_flags & MASK_DENSITY)
69 #define TARGET_MAC16 (target_flags & MASK_MAC16)
70 #define TARGET_MUL16 (target_flags & MASK_MUL16)
71 #define TARGET_MUL32 (target_flags & MASK_MUL32)
72 #define TARGET_DIV32 (target_flags & MASK_DIV32)
73 #define TARGET_NSA (target_flags & MASK_NSA)
74 #define TARGET_MINMAX (target_flags & MASK_MINMAX)
75 #define TARGET_SEXT (target_flags & MASK_SEXT)
76 #define TARGET_BOOLEANS (target_flags & MASK_BOOLEANS)
77 #define TARGET_HARD_FLOAT (target_flags & MASK_HARD_FLOAT)
78 #define TARGET_HARD_FLOAT_DIV (target_flags & MASK_HARD_FLOAT_DIV)
79 #define TARGET_HARD_FLOAT_RECIP (target_flags & MASK_HARD_FLOAT_RECIP)
80 #define TARGET_HARD_FLOAT_SQRT (target_flags & MASK_HARD_FLOAT_SQRT)
81 #define TARGET_HARD_FLOAT_RSQRT (target_flags & MASK_HARD_FLOAT_RSQRT)
82 #define TARGET_NO_FUSED_MADD (target_flags & MASK_NO_FUSED_MADD)
83 #define TARGET_SERIALIZE_VOLATILE (target_flags & MASK_SERIALIZE_VOLATILE)
85 /* Default target_flags if no switches are specified */
87 #define TARGET_DEFAULT ( \
88 (XCHAL_HAVE_BE ? MASK_BIG_ENDIAN : 0) | \
89 (XCHAL_HAVE_DENSITY ? MASK_DENSITY : 0) | \
90 (XCHAL_HAVE_MAC16 ? MASK_MAC16 : 0) | \
91 (XCHAL_HAVE_MUL16 ? MASK_MUL16 : 0) | \
92 (XCHAL_HAVE_MUL32 ? MASK_MUL32 : 0) | \
93 (XCHAL_HAVE_DIV32 ? MASK_DIV32 : 0) | \
94 (XCHAL_HAVE_NSA ? MASK_NSA : 0) | \
95 (XCHAL_HAVE_MINMAX ? MASK_MINMAX : 0) | \
96 (XCHAL_HAVE_SEXT ? MASK_SEXT : 0) | \
97 (XCHAL_HAVE_BOOLEANS ? MASK_BOOLEANS : 0) | \
98 (XCHAL_HAVE_FP ? MASK_HARD_FLOAT : 0) | \
99 (XCHAL_HAVE_FP_DIV ? MASK_HARD_FLOAT_DIV : 0) | \
100 (XCHAL_HAVE_FP_RECIP ? MASK_HARD_FLOAT_RECIP : 0) | \
101 (XCHAL_HAVE_FP_SQRT ? MASK_HARD_FLOAT_SQRT : 0) | \
102 (XCHAL_HAVE_FP_RSQRT ? MASK_HARD_FLOAT_RSQRT : 0) | \
103 MASK_SERIALIZE_VOLATILE)
105 /* Macro to define tables used to set the flags. */
107 #define TARGET_SWITCHES \
109 {"big-endian", MASK_BIG_ENDIAN, \
110 N_("Use big-endian byte order")}, \
111 {"little-endian", -MASK_BIG_ENDIAN, \
112 N_("Use little-endian byte order")}, \
113 {"density", MASK_DENSITY, \
114 N_("Use the Xtensa code density option")}, \
115 {"no-density", -MASK_DENSITY, \
116 N_("Do not use the Xtensa code density option")}, \
117 {"mac16", MASK_MAC16, \
118 N_("Use the Xtensa MAC16 option")}, \
119 {"no-mac16", -MASK_MAC16, \
120 N_("Do not use the Xtensa MAC16 option")}, \
121 {"mul16", MASK_MUL16, \
122 N_("Use the Xtensa MUL16 option")}, \
123 {"no-mul16", -MASK_MUL16, \
124 N_("Do not use the Xtensa MUL16 option")}, \
125 {"mul32", MASK_MUL32, \
126 N_("Use the Xtensa MUL32 option")}, \
127 {"no-mul32", -MASK_MUL32, \
128 N_("Do not use the Xtensa MUL32 option")}, \
129 {"div32", MASK_DIV32, \
130 0 /* undocumented */}, \
131 {"no-div32", -MASK_DIV32, \
132 0 /* undocumented */}, \
134 N_("Use the Xtensa NSA option")}, \
135 {"no-nsa", -MASK_NSA, \
136 N_("Do not use the Xtensa NSA option")}, \
137 {"minmax", MASK_MINMAX, \
138 N_("Use the Xtensa MIN/MAX option")}, \
139 {"no-minmax", -MASK_MINMAX, \
140 N_("Do not use the Xtensa MIN/MAX option")}, \
141 {"sext", MASK_SEXT, \
142 N_("Use the Xtensa SEXT option")}, \
143 {"no-sext", -MASK_SEXT, \
144 N_("Do not use the Xtensa SEXT option")}, \
145 {"booleans", MASK_BOOLEANS, \
146 N_("Use the Xtensa boolean register option")}, \
147 {"no-booleans", -MASK_BOOLEANS, \
148 N_("Do not use the Xtensa boolean register option")}, \
149 {"hard-float", MASK_HARD_FLOAT, \
150 N_("Use the Xtensa floating-point unit")}, \
151 {"soft-float", -MASK_HARD_FLOAT, \
152 N_("Do not use the Xtensa floating-point unit")}, \
153 {"hard-float-div", MASK_HARD_FLOAT_DIV, \
154 0 /* undocumented */}, \
155 {"no-hard-float-div", -MASK_HARD_FLOAT_DIV, \
156 0 /* undocumented */}, \
157 {"hard-float-recip", MASK_HARD_FLOAT_RECIP, \
158 0 /* undocumented */}, \
159 {"no-hard-float-recip", -MASK_HARD_FLOAT_RECIP, \
160 0 /* undocumented */}, \
161 {"hard-float-sqrt", MASK_HARD_FLOAT_SQRT, \
162 0 /* undocumented */}, \
163 {"no-hard-float-sqrt", -MASK_HARD_FLOAT_SQRT, \
164 0 /* undocumented */}, \
165 {"hard-float-rsqrt", MASK_HARD_FLOAT_RSQRT, \
166 0 /* undocumented */}, \
167 {"no-hard-float-rsqrt", -MASK_HARD_FLOAT_RSQRT, \
168 0 /* undocumented */}, \
169 {"no-fused-madd", MASK_NO_FUSED_MADD, \
170 N_("Disable fused multiply/add and multiply/subtract FP instructions")}, \
171 {"fused-madd", -MASK_NO_FUSED_MADD, \
172 N_("Enable fused multiply/add and multiply/subtract FP instructions")}, \
173 {"serialize-volatile", MASK_SERIALIZE_VOLATILE, \
174 N_("Serialize volatile memory references with MEMW instructions")}, \
175 {"no-serialize-volatile", -MASK_SERIALIZE_VOLATILE, \
176 N_("Do not serialize volatile memory references with MEMW instructions")},\
177 {"text-section-literals", 0, \
178 N_("Intersperse literal pools with code in the text section")}, \
179 {"no-text-section-literals", 0, \
180 N_("Put literal pools in a separate literal section")}, \
181 {"target-align", 0, \
182 N_("Automatically align branch targets to reduce branch penalties")}, \
183 {"no-target-align", 0, \
184 N_("Do not automatically align branch targets")}, \
186 N_("Use indirect CALLXn instructions for large programs")}, \
187 {"no-longcalls", 0, \
188 N_("Use direct CALLn instructions for fast calls")}, \
189 {"", TARGET_DEFAULT, 0} \
193 #define OVERRIDE_OPTIONS override_options ()
196 #define CPP_ENDIAN_SPEC "\
197 %{mlittle-endian:-D__XTENSA_EL__} \
198 %{!mlittle-endian:-D__XTENSA_EB__} "
199 #else /* !XCHAL_HAVE_BE */
200 #define CPP_ENDIAN_SPEC "\
201 %{mbig-endian:-D__XTENSA_EB__} \
202 %{!mbig-endian:-D__XTENSA_EL__} "
203 #endif /* !XCHAL_HAVE_BE */
206 #define CPP_FLOAT_SPEC "%{msoft-float:-D__XTENSA_SOFT_FLOAT__}"
208 #define CPP_FLOAT_SPEC "%{!mhard-float:-D__XTENSA_SOFT_FLOAT__}"
212 #define CPP_SPEC CPP_ENDIAN_SPEC CPP_FLOAT_SPEC
214 /* Define this to set the endianness to use in libgcc2.c, which can
215 not depend on target_flags. */
216 #define LIBGCC2_WORDS_BIG_ENDIAN XCHAL_HAVE_BE
218 /* Show we can debug even without a frame pointer. */
219 #define CAN_DEBUG_WITHOUT_FP
222 /* Target machine storage layout */
224 /* Define this if most significant bit is lowest numbered
225 in instructions that operate on numbered bit-fields. */
226 #define BITS_BIG_ENDIAN (TARGET_BIG_ENDIAN != 0)
228 /* Define this if most significant byte of a word is the lowest numbered. */
229 #define BYTES_BIG_ENDIAN (TARGET_BIG_ENDIAN != 0)
231 /* Define this if most significant word of a multiword number is the lowest. */
232 #define WORDS_BIG_ENDIAN (TARGET_BIG_ENDIAN != 0)
234 #define MAX_BITS_PER_WORD 32
236 /* Width of a word, in units (bytes). */
237 #define UNITS_PER_WORD 4
238 #define MIN_UNITS_PER_WORD 4
240 /* Width of a floating point register. */
241 #define UNITS_PER_FPREG 4
243 /* Size in bits of various types on the target machine. */
244 #define INT_TYPE_SIZE 32
245 #define SHORT_TYPE_SIZE 16
246 #define LONG_TYPE_SIZE 32
247 #define MAX_LONG_TYPE_SIZE 32
248 #define LONG_LONG_TYPE_SIZE 64
249 #define FLOAT_TYPE_SIZE 32
250 #define DOUBLE_TYPE_SIZE 64
251 #define LONG_DOUBLE_TYPE_SIZE 64
253 /* Tell the preprocessor the maximum size of wchar_t. */
254 #ifndef MAX_WCHAR_TYPE_SIZE
255 #ifndef WCHAR_TYPE_SIZE
259 /* Allocation boundary (in *bits*) for storing pointers in memory. */
260 #define POINTER_BOUNDARY 32
262 /* Allocation boundary (in *bits*) for storing arguments in argument list. */
263 #define PARM_BOUNDARY 32
265 /* Allocation boundary (in *bits*) for the code of a function. */
266 #define FUNCTION_BOUNDARY 32
268 /* Alignment of field after 'int : 0' in a structure. */
269 #define EMPTY_FIELD_BOUNDARY 32
271 /* Every structure's size must be a multiple of this. */
272 #define STRUCTURE_SIZE_BOUNDARY 8
274 /* There is no point aligning anything to a rounder boundary than this. */
275 #define BIGGEST_ALIGNMENT 128
277 /* Set this nonzero if move instructions will actually fail to work
278 when given unaligned data. */
279 #define STRICT_ALIGNMENT 1
281 /* Promote integer modes smaller than a word to SImode. Set UNSIGNEDP
282 for QImode, because there is no 8-bit load from memory with sign
283 extension. Otherwise, leave UNSIGNEDP alone, since Xtensa has 16-bit
284 loads both with and without sign extension. */
285 #define PROMOTE_MODE(MODE, UNSIGNEDP, TYPE) \
287 if (GET_MODE_CLASS (MODE) == MODE_INT \
288 && GET_MODE_SIZE (MODE) < UNITS_PER_WORD) \
290 if ((MODE) == QImode) \
296 /* The promotion described by `PROMOTE_MODE' should also be done for
297 outgoing function arguments. */
298 #define PROMOTE_FUNCTION_ARGS
300 /* The promotion described by `PROMOTE_MODE' should also be done for
301 the return value of functions. Note: `FUNCTION_VALUE' must perform
302 the same promotions done by `PROMOTE_MODE'. */
303 #define PROMOTE_FUNCTION_RETURN
305 /* Imitate the way many other C compilers handle alignment of
306 bitfields and the structures that contain them. */
307 #define PCC_BITFIELD_TYPE_MATTERS 1
309 /* Align string constants and constructors to at least a word boundary.
310 The typical use of this macro is to increase alignment for string
311 constants to be word aligned so that 'strcpy' calls that copy
312 constants can be done inline. */
313 #define CONSTANT_ALIGNMENT(EXP, ALIGN) \
314 ((TREE_CODE (EXP) == STRING_CST || TREE_CODE (EXP) == CONSTRUCTOR) \
315 && (ALIGN) < BITS_PER_WORD \
319 /* Align arrays, unions and records to at least a word boundary.
320 One use of this macro is to increase alignment of medium-size
321 data to make it all fit in fewer cache lines. Another is to
322 cause character arrays to be word-aligned so that 'strcpy' calls
323 that copy constants to character arrays can be done inline. */
324 #undef DATA_ALIGNMENT
325 #define DATA_ALIGNMENT(TYPE, ALIGN) \
326 ((((ALIGN) < BITS_PER_WORD) \
327 && (TREE_CODE (TYPE) == ARRAY_TYPE \
328 || TREE_CODE (TYPE) == UNION_TYPE \
329 || TREE_CODE (TYPE) == RECORD_TYPE)) ? BITS_PER_WORD : (ALIGN))
331 /* An argument declared as 'char' or 'short' in a prototype should
332 actually be passed as an 'int'. */
333 #define PROMOTE_PROTOTYPES 1
335 /* Operations between registers always perform the operation
336 on the full register even if a narrower mode is specified. */
337 #define WORD_REGISTER_OPERATIONS
339 /* Xtensa loads are zero-extended by default. */
340 #define LOAD_EXTEND_OP(MODE) ZERO_EXTEND
342 /* Standard register usage. */
344 /* Number of actual hardware registers.
345 The hardware registers are assigned numbers for the compiler
346 from 0 to just below FIRST_PSEUDO_REGISTER.
347 All registers that the compiler knows about must be given numbers,
348 even those that are not normally considered general registers.
350 The fake frame pointer and argument pointer will never appear in
351 the generated code, since they will always be eliminated and replaced
352 by either the stack pointer or the hard frame pointer.
354 0 - 15 AR[0] - AR[15]
355 16 FRAME_POINTER (fake = initial sp)
356 17 ARG_POINTER (fake = initial sp + framesize)
357 18 LOOP_COUNT (loop count special register)
358 18 BR[0] for floating-point CC
359 19 - 34 FR[0] - FR[15]
360 35 MAC16 accumulator */
362 #define FIRST_PSEUDO_REGISTER 36
364 /* Return the stabs register number to use for REGNO. */
365 #define DBX_REGISTER_NUMBER(REGNO) xtensa_dbx_register_number (REGNO)
367 /* 1 for registers that have pervasive standard uses
368 and are not available for the register allocator. */
369 #define FIXED_REGISTERS \
371 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, \
373 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, \
377 /* 1 for registers not available across function calls.
378 These must include the FIXED_REGISTERS and also any
379 registers that can be used without being saved.
380 The latter must include the registers where values are returned
381 and the register where structure-value addresses are passed.
382 Aside from that, you can include as many other registers as you like. */
383 #define CALL_USED_REGISTERS \
385 1, 1, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1, \
387 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, \
391 /* For non-leaf procedures on Xtensa processors, the allocation order
392 is as specified below by REG_ALLOC_ORDER. For leaf procedures, we
393 want to use the lowest numbered registers first to minimize
394 register window overflows. However, local-alloc is not smart
395 enough to consider conflicts with incoming arguments. If an
396 incoming argument in a2 is live throughout the function and
397 local-alloc decides to use a2, then the incoming argument must
398 either be spilled or copied to another register. To get around
399 this, we define ORDER_REGS_FOR_LOCAL_ALLOC to redefine
400 reg_alloc_order for leaf functions such that lowest numbered
401 registers are used first with the exception that the incoming
402 argument registers are not used until after other register choices
403 have been exhausted. */
405 #define REG_ALLOC_ORDER \
406 { 8, 9, 10, 11, 12, 13, 14, 15, 7, 6, 5, 4, 3, 2, 19, \
407 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, \
412 #define ORDER_REGS_FOR_LOCAL_ALLOC order_regs_for_local_alloc ()
414 /* For Xtensa, the only point of this is to prevent GCC from otherwise
415 giving preference to call-used registers. To minimize window
416 overflows for the AR registers, we want to give preference to the
417 lower-numbered AR registers. For other register files, which are
418 not windowed, we still prefer call-used registers, if there are any. */
419 extern const char xtensa_leaf_regs[FIRST_PSEUDO_REGISTER];
420 #define LEAF_REGISTERS xtensa_leaf_regs
422 /* For Xtensa, no remapping is necessary, but this macro must be
423 defined if LEAF_REGISTERS is defined. */
424 #define LEAF_REG_REMAP(REGNO) (REGNO)
426 /* this must be declared if LEAF_REGISTERS is set */
427 extern int leaf_function;
429 /* Internal macros to classify a register number. */
431 /* 16 address registers + fake registers */
432 #define GP_REG_FIRST 0
433 #define GP_REG_LAST 17
434 #define GP_REG_NUM (GP_REG_LAST - GP_REG_FIRST + 1)
436 /* Special registers */
437 #define SPEC_REG_FIRST 18
438 #define SPEC_REG_LAST 18
439 #define SPEC_REG_NUM (SPEC_REG_LAST - SPEC_REG_FIRST + 1)
441 /* Coprocessor registers */
442 #define BR_REG_FIRST 18
443 #define BR_REG_LAST 18
444 #define BR_REG_NUM (BR_REG_LAST - BR_REG_FIRST + 1)
446 /* 16 floating-point registers */
447 #define FP_REG_FIRST 19
448 #define FP_REG_LAST 34
449 #define FP_REG_NUM (FP_REG_LAST - FP_REG_FIRST + 1)
451 /* MAC16 accumulator */
452 #define ACC_REG_FIRST 35
453 #define ACC_REG_LAST 35
454 #define ACC_REG_NUM (ACC_REG_LAST - ACC_REG_FIRST + 1)
456 #define GP_REG_P(REGNO) ((unsigned) ((REGNO) - GP_REG_FIRST) < GP_REG_NUM)
457 #define BR_REG_P(REGNO) ((unsigned) ((REGNO) - BR_REG_FIRST) < BR_REG_NUM)
458 #define FP_REG_P(REGNO) ((unsigned) ((REGNO) - FP_REG_FIRST) < FP_REG_NUM)
459 #define ACC_REG_P(REGNO) ((unsigned) ((REGNO) - ACC_REG_FIRST) < ACC_REG_NUM)
461 /* Return number of consecutive hard regs needed starting at reg REGNO
462 to hold something of mode MODE. */
463 #define HARD_REGNO_NREGS(REGNO, MODE) \
464 (FP_REG_P (REGNO) ? \
465 ((GET_MODE_SIZE (MODE) + UNITS_PER_FPREG - 1) / UNITS_PER_FPREG) : \
466 ((GET_MODE_SIZE (MODE) + UNITS_PER_WORD - 1) / UNITS_PER_WORD))
468 /* Value is 1 if hard register REGNO can hold a value of machine-mode
470 extern char xtensa_hard_regno_mode_ok[][FIRST_PSEUDO_REGISTER];
472 #define HARD_REGNO_MODE_OK(REGNO, MODE) \
473 xtensa_hard_regno_mode_ok[(int) (MODE)][(REGNO)]
475 /* Value is 1 if it is a good idea to tie two pseudo registers
476 when one has mode MODE1 and one has mode MODE2.
477 If HARD_REGNO_MODE_OK could produce different values for MODE1 and MODE2,
478 for any hard reg, then this must be 0 for correct output. */
479 #define MODES_TIEABLE_P(MODE1, MODE2) \
480 ((GET_MODE_CLASS (MODE1) == MODE_FLOAT || \
481 GET_MODE_CLASS (MODE1) == MODE_COMPLEX_FLOAT) \
482 == (GET_MODE_CLASS (MODE2) == MODE_FLOAT || \
483 GET_MODE_CLASS (MODE2) == MODE_COMPLEX_FLOAT))
485 /* Register to use for LCOUNT special register. */
486 #define COUNT_REGISTER_REGNUM (SPEC_REG_FIRST + 0)
488 /* Register to use for pushing function arguments. */
489 #define STACK_POINTER_REGNUM (GP_REG_FIRST + 1)
491 /* Base register for access to local variables of the function. */
492 #define HARD_FRAME_POINTER_REGNUM (GP_REG_FIRST + 7)
494 /* The register number of the frame pointer register, which is used to
495 access automatic variables in the stack frame. For Xtensa, this
496 register never appears in the output. It is always eliminated to
497 either the stack pointer or the hard frame pointer. */
498 #define FRAME_POINTER_REGNUM (GP_REG_FIRST + 16)
500 /* Value should be nonzero if functions must have frame pointers.
501 Zero means the frame pointer need not be set up (and parms
502 may be accessed via the stack pointer) in functions that seem suitable.
503 This is computed in 'reload', in reload1.c. */
504 #define FRAME_POINTER_REQUIRED xtensa_frame_pointer_required ()
506 /* Base register for access to arguments of the function. */
507 #define ARG_POINTER_REGNUM (GP_REG_FIRST + 17)
509 /* If the static chain is passed in memory, these macros provide rtx
510 giving 'mem' expressions that denote where they are stored.
511 'STATIC_CHAIN' and 'STATIC_CHAIN_INCOMING' give the locations as
512 seen by the calling and called functions, respectively. */
514 #define STATIC_CHAIN \
515 gen_rtx_MEM (Pmode, plus_constant (stack_pointer_rtx, -5 * UNITS_PER_WORD))
517 #define STATIC_CHAIN_INCOMING \
518 gen_rtx_MEM (Pmode, plus_constant (arg_pointer_rtx, -5 * UNITS_PER_WORD))
520 /* For now we don't try to use the full set of boolean registers. Without
521 software pipelining of FP operations, there's not much to gain and it's
522 a real pain to get them reloaded. */
523 #define FPCC_REGNUM (BR_REG_FIRST + 0)
525 /* Pass structure value address as an "invisible" first argument. */
526 #define STRUCT_VALUE 0
528 /* It is as good or better to call a constant function address than to
529 call an address kept in a register. */
530 #define NO_FUNCTION_CSE 1
532 /* It is as good or better for a function to call itself with an
533 explicit address than to call an address kept in a register. */
534 #define NO_RECURSIVE_FUNCTION_CSE 1
536 /* Xtensa processors have "register windows". GCC does not currently
537 take advantage of the possibility for variable-sized windows; instead,
538 we use a fixed window size of 8. */
540 #define INCOMING_REGNO(OUT) \
541 ((GP_REG_P (OUT) && \
542 ((unsigned) ((OUT) - GP_REG_FIRST) >= WINDOW_SIZE)) ? \
543 (OUT) - WINDOW_SIZE : (OUT))
545 #define OUTGOING_REGNO(IN) \
547 ((unsigned) ((IN) - GP_REG_FIRST) < WINDOW_SIZE)) ? \
548 (IN) + WINDOW_SIZE : (IN))
551 /* Define the classes of registers for register constraints in the
552 machine description. */
555 NO_REGS, /* no registers in set */
556 BR_REGS, /* coprocessor boolean registers */
557 FP_REGS, /* floating point registers */
558 ACC_REG, /* MAC16 accumulator */
559 SP_REG, /* sp register (aka a1) */
560 GR_REGS, /* integer registers except sp */
561 AR_REGS, /* all integer registers */
562 ALL_REGS, /* all registers */
563 LIM_REG_CLASSES /* max value + 1 */
566 #define N_REG_CLASSES (int) LIM_REG_CLASSES
568 #define GENERAL_REGS AR_REGS
570 /* An initializer containing the names of the register classes as C
571 string constants. These names are used in writing some of the
573 #define REG_CLASS_NAMES \
585 /* Contents of the register classes. The Nth integer specifies the
586 contents of class N. The way the integer MASK is interpreted is
587 that register R is in the class if 'MASK & (1 << R)' is 1. */
588 #define REG_CLASS_CONTENTS \
590 { 0x00000000, 0x00000000 }, /* no registers */ \
591 { 0x00040000, 0x00000000 }, /* coprocessor boolean registers */ \
592 { 0xfff80000, 0x00000007 }, /* floating-point registers */ \
593 { 0x00000000, 0x00000008 }, /* MAC16 accumulator */ \
594 { 0x00000002, 0x00000000 }, /* stack pointer register */ \
595 { 0x0000fffd, 0x00000000 }, /* general-purpose registers */ \
596 { 0x0003ffff, 0x00000000 }, /* integer registers */ \
597 { 0xffffffff, 0x0000000f } /* all registers */ \
600 /* A C expression whose value is a register class containing hard
601 register REGNO. In general there is more that one such class;
602 choose a class which is "minimal", meaning that no smaller class
603 also contains the register. */
604 extern const enum reg_class xtensa_regno_to_class[FIRST_PSEUDO_REGISTER];
606 #define REGNO_REG_CLASS(REGNO) xtensa_regno_to_class[ (REGNO) ]
608 /* Use the Xtensa AR register file for base registers.
609 No index registers. */
610 #define BASE_REG_CLASS AR_REGS
611 #define INDEX_REG_CLASS NO_REGS
613 /* SMALL_REGISTER_CLASSES is required for Xtensa, because all of the
614 16 AR registers may be explicitly used in the RTL, as either
615 incoming or outgoing arguments. */
616 #define SMALL_REGISTER_CLASSES 1
619 /* REGISTER AND CONSTANT CLASSES */
621 /* Get reg_class from a letter such as appears in the machine
624 Available letters: a-f,h,j-l,q,t-z,A-D,W,Y-Z
626 DEFINED REGISTER CLASSES:
628 'a' general-purpose registers except sp
630 'D' general-purpose registers (only if density option enabled)
631 'd' general-purpose registers, including sp (only if density enabled)
632 'A' MAC16 accumulator (only if MAC16 option enabled)
633 'B' general-purpose registers (only if sext instruction enabled)
634 'C' general-purpose registers (only if mul16 option enabled)
635 'b' coprocessor boolean registers
636 'f' floating-point registers
639 extern enum reg_class xtensa_char_to_class[256];
641 #define REG_CLASS_FROM_LETTER(C) xtensa_char_to_class[ (int) (C) ]
643 /* The letters I, J, K, L, M, N, O, and P in a register constraint
644 string can be used to stand for particular ranges of immediate
645 operands. This macro defines what the ranges are. C is the
646 letter, and VALUE is a constant value. Return 1 if VALUE is
647 in the range specified by C.
651 I = 12-bit signed immediate for movi
652 J = 8-bit signed immediate for addi
653 K = 4-bit value in (b4const U {0})
654 L = 4-bit value in b4constu
655 M = 7-bit value in simm7
656 N = 8-bit unsigned immediate shifted left by 8 bits for addmi
657 O = 4-bit value in ai4const
658 P = valid immediate mask value for extui */
660 #define CONST_OK_FOR_LETTER_P(VALUE, C) \
661 ((C) == 'I' ? (xtensa_simm12b (VALUE)) \
662 : (C) == 'J' ? (xtensa_simm8 (VALUE)) \
663 : (C) == 'K' ? (((VALUE) == 0) || xtensa_b4const (VALUE)) \
664 : (C) == 'L' ? (xtensa_b4constu (VALUE)) \
665 : (C) == 'M' ? (xtensa_simm7 (VALUE)) \
666 : (C) == 'N' ? (xtensa_simm8x256 (VALUE)) \
667 : (C) == 'O' ? (xtensa_ai4const (VALUE)) \
668 : (C) == 'P' ? (xtensa_mask_immediate (VALUE)) \
672 /* Similar, but for floating constants, and defining letters G and H.
673 Here VALUE is the CONST_DOUBLE rtx itself. */
674 #define CONST_DOUBLE_OK_FOR_LETTER_P(VALUE, C) (0)
677 /* Other letters can be defined in a machine-dependent fashion to
678 stand for particular classes of registers or other arbitrary
681 R = memory that can be accessed with a 4-bit unsigned offset
682 S = memory where the second word can be addressed with a 4-bit offset
683 T = memory in a constant pool (addressable with a pc-relative load)
684 U = memory *NOT* in a constant pool
686 The offset range should not be checked here (except to distinguish
687 denser versions of the instructions for which more general versions
688 are available). Doing so leads to problems in reloading: an
689 argptr-relative address may become invalid when the phony argptr is
690 eliminated in favor of the stack pointer (the offset becomes too
691 large to fit in the instruction's immediate field); a reload is
692 generated to fix this but the RTL is not immediately updated; in
693 the meantime, the constraints are checked and none match. The
694 solution seems to be to simply skip the offset check here. The
695 address will be checked anyway because of the code in
696 GO_IF_LEGITIMATE_ADDRESS. */
698 #define EXTRA_CONSTRAINT(OP, CODE) \
699 ((GET_CODE (OP) != MEM) ? \
700 ((CODE) >= 'R' && (CODE) <= 'U' \
701 && reload_in_progress && GET_CODE (OP) == REG \
702 && REGNO (OP) >= FIRST_PSEUDO_REGISTER) \
703 : ((CODE) == 'R') ? smalloffset_mem_p (OP) \
704 : ((CODE) == 'S') ? smalloffset_double_mem_p (OP) \
705 : ((CODE) == 'T') ? constantpool_mem_p (OP) \
706 : ((CODE) == 'U') ? !constantpool_mem_p (OP) \
709 #define PREFERRED_RELOAD_CLASS(X, CLASS) \
710 xtensa_preferred_reload_class (X, CLASS)
712 #define PREFERRED_OUTPUT_RELOAD_CLASS(X, CLASS) \
715 #define SECONDARY_INPUT_RELOAD_CLASS(CLASS, MODE, X) \
716 xtensa_secondary_reload_class (CLASS, MODE, X, 0)
718 #define SECONDARY_OUTPUT_RELOAD_CLASS(CLASS, MODE, X) \
719 xtensa_secondary_reload_class (CLASS, MODE, X, 1)
721 /* Return the maximum number of consecutive registers
722 needed to represent mode MODE in a register of class CLASS. */
723 #define CLASS_UNITS(mode, size) \
724 ((GET_MODE_SIZE (mode) + (size) - 1) / (size))
726 #define CLASS_MAX_NREGS(CLASS, MODE) \
727 (CLASS_UNITS (MODE, UNITS_PER_WORD))
730 /* Stack layout; function entry, exit and calling. */
732 #define STACK_GROWS_DOWNWARD
734 /* Offset within stack frame to start allocating local variables at. */
735 #define STARTING_FRAME_OFFSET \
736 current_function_outgoing_args_size
738 /* The ARG_POINTER and FRAME_POINTER are not real Xtensa registers, so
739 they are eliminated to either the stack pointer or hard frame pointer. */
740 #define ELIMINABLE_REGS \
741 {{ ARG_POINTER_REGNUM, STACK_POINTER_REGNUM}, \
742 { ARG_POINTER_REGNUM, HARD_FRAME_POINTER_REGNUM}, \
743 { FRAME_POINTER_REGNUM, STACK_POINTER_REGNUM}, \
744 { FRAME_POINTER_REGNUM, HARD_FRAME_POINTER_REGNUM}}
746 #define CAN_ELIMINATE(FROM, TO) 1
748 /* Specify the initial difference between the specified pair of registers. */
749 #define INITIAL_ELIMINATION_OFFSET(FROM, TO, OFFSET) \
751 compute_frame_size (get_frame_size ()); \
752 if ((FROM) == FRAME_POINTER_REGNUM) \
754 else if ((FROM) == ARG_POINTER_REGNUM) \
755 (OFFSET) = xtensa_current_frame_size; \
760 /* If defined, the maximum amount of space required for outgoing
761 arguments will be computed and placed into the variable
762 'current_function_outgoing_args_size'. No space will be pushed
763 onto the stack for each call; instead, the function prologue
764 should increase the stack frame size by this amount. */
765 #define ACCUMULATE_OUTGOING_ARGS 1
767 /* Offset from the argument pointer register to the first argument's
768 address. On some machines it may depend on the data type of the
769 function. If 'ARGS_GROW_DOWNWARD', this is the offset to the
770 location above the first argument's address. */
771 #define FIRST_PARM_OFFSET(FNDECL) 0
773 /* Align stack frames on 128 bits for Xtensa. This is necessary for
774 128-bit datatypes defined in TIE (e.g., for Vectra). */
775 #define STACK_BOUNDARY 128
777 /* Functions do not pop arguments off the stack. */
778 #define RETURN_POPS_ARGS(FUNDECL, FUNTYPE, SIZE) 0
780 /* Use a fixed register window size of 8. */
781 #define WINDOW_SIZE 8
783 /* Symbolic macros for the registers used to return integer, floating
784 point, and values of coprocessor and user-defined modes. */
785 #define GP_RETURN (GP_REG_FIRST + 2 + WINDOW_SIZE)
786 #define GP_OUTGOING_RETURN (GP_REG_FIRST + 2)
788 /* Symbolic macros for the first/last argument registers. */
789 #define GP_ARG_FIRST (GP_REG_FIRST + 2)
790 #define GP_ARG_LAST (GP_REG_FIRST + 7)
791 #define GP_OUTGOING_ARG_FIRST (GP_REG_FIRST + 2 + WINDOW_SIZE)
792 #define GP_OUTGOING_ARG_LAST (GP_REG_FIRST + 7 + WINDOW_SIZE)
794 #define MAX_ARGS_IN_REGISTERS 6
796 /* Don't worry about compatibility with PCC. */
797 #define DEFAULT_PCC_STRUCT_RETURN 0
799 /* For Xtensa, up to 4 words can be returned in registers. (It would
800 have been nice to allow up to 6 words in registers but GCC cannot
801 support that. The return value must be given one of the standard
802 MODE_INT modes, and there is no 6 word mode. Instead, if we try to
803 return a 6 word structure, GCC selects the next biggest mode
804 (OImode, 8 words) and then the register allocator fails because
805 there is no 8-register group beginning with a10.) */
806 #define RETURN_IN_MEMORY(TYPE) \
807 ((unsigned HOST_WIDE_INT) int_size_in_bytes (TYPE) > 4 * UNITS_PER_WORD)
809 /* Define how to find the value returned by a library function
810 assuming the value has mode MODE. Because we have defined
811 PROMOTE_FUNCTION_RETURN, we have to perform the same promotions as
813 #define XTENSA_LIBCALL_VALUE(MODE, OUTGOINGP) \
814 gen_rtx_REG ((GET_MODE_CLASS (MODE) == MODE_INT \
815 && GET_MODE_SIZE (MODE) < UNITS_PER_WORD) \
817 OUTGOINGP ? GP_OUTGOING_RETURN : GP_RETURN)
819 #define LIBCALL_VALUE(MODE) \
820 XTENSA_LIBCALL_VALUE ((MODE), 0)
822 #define LIBCALL_OUTGOING_VALUE(MODE) \
823 XTENSA_LIBCALL_VALUE ((MODE), 1)
825 /* Define how to find the value returned by a function.
826 VALTYPE is the data type of the value (as a tree).
827 If the precise function being called is known, FUNC is its FUNCTION_DECL;
828 otherwise, FUNC is 0. */
829 #define XTENSA_FUNCTION_VALUE(VALTYPE, FUNC, OUTGOINGP) \
830 gen_rtx_REG ((INTEGRAL_TYPE_P (VALTYPE) \
831 && TYPE_PRECISION (VALTYPE) < BITS_PER_WORD) \
832 ? SImode: TYPE_MODE (VALTYPE), \
833 OUTGOINGP ? GP_OUTGOING_RETURN : GP_RETURN)
835 #define FUNCTION_VALUE(VALTYPE, FUNC) \
836 XTENSA_FUNCTION_VALUE (VALTYPE, FUNC, 0)
838 #define FUNCTION_OUTGOING_VALUE(VALTYPE, FUNC) \
839 XTENSA_FUNCTION_VALUE (VALTYPE, FUNC, 1)
841 /* A C expression that is nonzero if REGNO is the number of a hard
842 register in which the values of called function may come back. A
843 register whose use for returning values is limited to serving as
844 the second of a pair (for a value of type 'double', say) need not
845 be recognized by this macro. If the machine has register windows,
846 so that the caller and the called function use different registers
847 for the return value, this macro should recognize only the caller's
849 #define FUNCTION_VALUE_REGNO_P(N) \
852 /* A C expression that is nonzero if REGNO is the number of a hard
853 register in which function arguments are sometimes passed. This
854 does *not* include implicit arguments such as the static chain and
855 the structure-value address. On many machines, no registers can be
856 used for this purpose since all function arguments are pushed on
858 #define FUNCTION_ARG_REGNO_P(N) \
859 ((N) >= GP_OUTGOING_ARG_FIRST && (N) <= GP_OUTGOING_ARG_LAST)
861 /* Use IEEE floating-point format. */
862 #define TARGET_FLOAT_FORMAT IEEE_FLOAT_FORMAT
864 /* Define a data type for recording info about an argument list
865 during the scan of that argument list. This data type should
866 hold all necessary information about the function itself
867 and about the args processed so far, enough to enable macros
868 such as FUNCTION_ARG to determine where the next arg should go. */
869 typedef struct xtensa_args {
870 int arg_words; /* # total words the arguments take */
873 /* Initialize a variable CUM of type CUMULATIVE_ARGS
874 for a call to a function whose data type is FNTYPE.
875 For a library call, FNTYPE is 0. */
876 #define INIT_CUMULATIVE_ARGS(CUM, FNTYPE, LIBNAME, INDIRECT) \
877 init_cumulative_args (&CUM, FNTYPE, LIBNAME)
879 #define INIT_CUMULATIVE_INCOMING_ARGS(CUM, FNTYPE, LIBNAME) \
880 init_cumulative_args (&CUM, FNTYPE, LIBNAME)
882 /* Update the data in CUM to advance over an argument
883 of mode MODE and data type TYPE.
884 (TYPE is null for libcalls where that information may not be available.) */
885 #define FUNCTION_ARG_ADVANCE(CUM, MODE, TYPE, NAMED) \
886 function_arg_advance (&CUM, MODE, TYPE)
888 #define FUNCTION_ARG(CUM, MODE, TYPE, NAMED) \
889 function_arg (&CUM, MODE, TYPE, FALSE)
891 #define FUNCTION_INCOMING_ARG(CUM, MODE, TYPE, NAMED) \
892 function_arg (&CUM, MODE, TYPE, TRUE)
894 /* Arguments are never passed partly in memory and partly in registers. */
895 #define FUNCTION_ARG_PARTIAL_NREGS(CUM, MODE, TYPE, NAMED) (0)
897 /* Specify function argument alignment. */
898 #define FUNCTION_ARG_BOUNDARY(MODE, TYPE) \
900 ? (TYPE_ALIGN (TYPE) <= PARM_BOUNDARY \
902 : TYPE_ALIGN (TYPE)) \
903 : (GET_MODE_ALIGNMENT (MODE) <= PARM_BOUNDARY \
905 : GET_MODE_ALIGNMENT (MODE)))
908 /* Nonzero if we do not know how to pass TYPE solely in registers.
909 We cannot do so in the following cases:
911 - if the type has variable size
912 - if the type is marked as addressable (it is required to be constructed
915 This differs from the default in that it does not check if the padding
916 and mode of the type are such that a copy into a register would put it
917 into the wrong part of the register. */
919 #define MUST_PASS_IN_STACK(MODE, TYPE) \
921 && (TREE_CODE (TYPE_SIZE (TYPE)) != INTEGER_CST \
922 || TREE_ADDRESSABLE (TYPE)))
924 /* Profiling Xtensa code is typically done with the built-in profiling
925 feature of Tensilica's instruction set simulator, which does not
926 require any compiler support. Profiling code on a real (i.e.,
927 non-simulated) Xtensa processor is currently only supported by
928 GNU/Linux with glibc. The glibc version of _mcount doesn't require
929 counter variables. The _mcount function needs the current PC and
930 the current return address to identify an arc in the call graph.
931 Pass the current return address as the first argument; the current
932 PC is available as a0 in _mcount's register window. Both of these
933 values contain window size information in the two most significant
934 bits; we assume that _mcount will mask off those bits. The call to
935 _mcount uses a window size of 8 to make sure that it doesn't clobber
936 any incoming argument values. */
938 #define NO_PROFILE_COUNTERS
940 #define FUNCTION_PROFILER(FILE, LABELNO) \
942 fprintf (FILE, "\t%s\ta10, a0\n", TARGET_DENSITY ? "mov.n" : "mov"); \
945 fprintf (FILE, "\tmovi\ta8, _mcount@PLT\n"); \
946 fprintf (FILE, "\tcallx8\ta8\n"); \
949 fprintf (FILE, "\tcall8\t_mcount\n"); \
952 /* Stack pointer value doesn't matter at exit. */
953 #define EXIT_IGNORE_STACK 1
955 /* A C statement to output, on the stream FILE, assembler code for a
956 block of data that contains the constant parts of a trampoline.
957 This code should not include a label--the label is taken care of
960 For Xtensa, the trampoline must perform an entry instruction with a
961 minimal stack frame in order to get some free registers. Once the
962 actual call target is known, the proper stack frame size is extracted
963 from the entry instruction at the target and the current frame is
964 adjusted to match. The trampoline then transfers control to the
965 instruction following the entry at the target. Note: this assumes
966 that the target begins with an entry instruction. */
968 /* minimum frame = reg save area (4 words) plus static chain (1 word)
969 and the total number of words must be a multiple of 128 bits */
970 #define MIN_FRAME_SIZE (8 * UNITS_PER_WORD)
972 #define TRAMPOLINE_TEMPLATE(STREAM) \
974 fprintf (STREAM, "\t.begin no-generics\n"); \
975 fprintf (STREAM, "\tentry\tsp, %d\n", MIN_FRAME_SIZE); \
977 /* GCC isn't prepared to deal with data at the beginning of the \
978 trampoline, and the Xtensa l32r instruction requires that the \
979 constant pool be located before the code. We put the constant \
980 pool in the middle of the trampoline and jump around it. */ \
982 fprintf (STREAM, "\tj\t.Lskipconsts\n"); \
983 fprintf (STREAM, "\t.align\t4\n"); \
984 fprintf (STREAM, ".Lfnaddr:%s0\n", integer_asm_op (4, TRUE)); \
985 fprintf (STREAM, ".Lchainval:%s0\n", integer_asm_op (4, TRUE)); \
986 fprintf (STREAM, ".Lskipconsts:\n"); \
988 /* store the static chain */ \
989 fprintf (STREAM, "\tl32r\ta8, .Lchainval\n"); \
990 fprintf (STREAM, "\ts32i\ta8, sp, %d\n", \
991 MIN_FRAME_SIZE - (5 * UNITS_PER_WORD)); \
993 /* set the proper stack pointer value */ \
994 fprintf (STREAM, "\tl32r\ta8, .Lfnaddr\n"); \
995 fprintf (STREAM, "\tl32i\ta9, a8, 0\n"); \
996 fprintf (STREAM, "\textui\ta9, a9, %d, 12\n", \
997 TARGET_BIG_ENDIAN ? 8 : 12); \
998 fprintf (STREAM, "\tslli\ta9, a9, 3\n"); \
999 fprintf (STREAM, "\taddi\ta9, a9, %d\n", -MIN_FRAME_SIZE); \
1000 fprintf (STREAM, "\tsub\ta9, sp, a9\n"); \
1001 fprintf (STREAM, "\tmovsp\tsp, a9\n"); \
1003 /* jump to the instruction following the entry */ \
1004 fprintf (STREAM, "\taddi\ta8, a8, 3\n"); \
1005 fprintf (STREAM, "\tjx\ta8\n"); \
1006 fprintf (STREAM, "\t.end no-generics\n"); \
1009 /* Size in bytes of the trampoline, as an integer. */
1010 #define TRAMPOLINE_SIZE 49
1012 /* Alignment required for trampolines, in bits. */
1013 #define TRAMPOLINE_ALIGNMENT (32)
1015 /* A C statement to initialize the variable parts of a trampoline. */
1016 #define INITIALIZE_TRAMPOLINE(ADDR, FUNC, CHAIN) \
1019 emit_move_insn (gen_rtx_MEM (SImode, plus_constant (addr, 8)), FUNC); \
1020 emit_move_insn (gen_rtx_MEM (SImode, plus_constant (addr, 12)), CHAIN); \
1021 emit_library_call (gen_rtx (SYMBOL_REF, Pmode, "__xtensa_sync_caches"), \
1022 0, VOIDmode, 1, addr, Pmode); \
1025 /* Define the `__builtin_va_list' type for the ABI. */
1026 #define BUILD_VA_LIST_TYPE(VALIST) \
1027 (VALIST) = xtensa_build_va_list ()
1029 /* If defined, is a C expression that produces the machine-specific
1030 code for a call to '__builtin_saveregs'. This code will be moved
1031 to the very beginning of the function, before any parameter access
1032 are made. The return value of this function should be an RTX that
1033 contains the value to use as the return of '__builtin_saveregs'. */
1034 #define EXPAND_BUILTIN_SAVEREGS \
1035 xtensa_builtin_saveregs
1037 /* Implement `va_start' for varargs and stdarg. */
1038 #define EXPAND_BUILTIN_VA_START(stdarg, valist, nextarg) \
1039 xtensa_va_start (stdarg, valist, nextarg)
1041 /* Implement `va_arg'. */
1042 #define EXPAND_BUILTIN_VA_ARG(valist, type) \
1043 xtensa_va_arg (valist, type)
1045 /* If defined, a C expression that produces the machine-specific code
1046 to setup the stack so that arbitrary frames can be accessed.
1048 On Xtensa, a stack back-trace must always begin from the stack pointer,
1049 so that the register overflow save area can be located. However, the
1050 stack-walking code in GCC always begins from the hard_frame_pointer
1051 register, not the stack pointer. The frame pointer is usually equal
1052 to the stack pointer, but the __builtin_return_address and
1053 __builtin_frame_address functions will not work if count > 0 and
1054 they are called from a routine that uses alloca. These functions
1055 are not guaranteed to work at all if count > 0 so maybe that is OK.
1057 A nicer solution would be to allow the architecture-specific files to
1058 specify whether to start from the stack pointer or frame pointer. That
1059 would also allow us to skip the machine->accesses_prev_frame stuff that
1060 we currently need to ensure that there is a frame pointer when these
1061 builtin functions are used. */
1063 #define SETUP_FRAME_ADDRESSES xtensa_setup_frame_addresses
1065 /* A C expression whose value is RTL representing the address in a
1066 stack frame where the pointer to the caller's frame is stored.
1067 Assume that FRAMEADDR is an RTL expression for the address of the
1070 For Xtensa, there is no easy way to get the frame pointer if it is
1071 not equivalent to the stack pointer. Moreover, the result of this
1072 macro is used for continuing to walk back up the stack, so it must
1073 return the stack pointer address. Thus, there is some inconsistency
1074 here in that __builtin_frame_address will return the frame pointer
1075 when count == 0 and the stack pointer when count > 0. */
1077 #define DYNAMIC_CHAIN_ADDRESS(frame) \
1078 gen_rtx (PLUS, Pmode, frame, \
1079 gen_rtx_CONST_INT (VOIDmode, -3 * UNITS_PER_WORD))
1081 /* Define this if the return address of a particular stack frame is
1082 accessed from the frame pointer of the previous stack frame. */
1083 #define RETURN_ADDR_IN_PREVIOUS_FRAME
1085 /* A C expression whose value is RTL representing the value of the
1086 return address for the frame COUNT steps up from the current
1087 frame, after the prologue. */
1088 #define RETURN_ADDR_RTX xtensa_return_addr
1090 /* Addressing modes, and classification of registers for them. */
1092 /* C expressions which are nonzero if register number NUM is suitable
1093 for use as a base or index register in operand addresses. It may
1094 be either a suitable hard register or a pseudo register that has
1095 been allocated such a hard register. The difference between an
1096 index register and a base register is that the index register may
1099 #define REGNO_OK_FOR_BASE_P(NUM) \
1100 (GP_REG_P (NUM) || GP_REG_P ((unsigned) reg_renumber[NUM]))
1102 #define REGNO_OK_FOR_INDEX_P(NUM) 0
1104 /* C expressions that are nonzero if X (assumed to be a `reg' RTX) is
1105 valid for use as a base or index register. For hard registers, it
1106 should always accept those which the hardware permits and reject
1107 the others. Whether the macro accepts or rejects pseudo registers
1108 must be controlled by `REG_OK_STRICT'. This usually requires two
1109 variant definitions, of which `REG_OK_STRICT' controls the one
1110 actually used. The difference between an index register and a base
1111 register is that the index register may be scaled. */
1113 #ifdef REG_OK_STRICT
1115 #define REG_OK_FOR_INDEX_P(X) 0
1116 #define REG_OK_FOR_BASE_P(X) \
1117 REGNO_OK_FOR_BASE_P (REGNO (X))
1119 #else /* !REG_OK_STRICT */
1121 #define REG_OK_FOR_INDEX_P(X) 0
1122 #define REG_OK_FOR_BASE_P(X) \
1123 ((REGNO (X) >= FIRST_PSEUDO_REGISTER) || (GP_REG_P (REGNO (X))))
1125 #endif /* !REG_OK_STRICT */
1127 /* Maximum number of registers that can appear in a valid memory address. */
1128 #define MAX_REGS_PER_ADDRESS 1
1130 /* Identify valid Xtensa addresses. */
1131 #define GO_IF_LEGITIMATE_ADDRESS(MODE, ADDR, LABEL) \
1133 rtx xinsn = (ADDR); \
1135 /* allow constant pool addresses */ \
1136 if ((MODE) != BLKmode && GET_MODE_SIZE (MODE) >= UNITS_PER_WORD \
1137 && constantpool_address_p (xinsn)) \
1140 while (GET_CODE (xinsn) == SUBREG) \
1141 xinsn = SUBREG_REG (xinsn); \
1143 /* allow base registers */ \
1144 if (GET_CODE (xinsn) == REG && REG_OK_FOR_BASE_P (xinsn)) \
1147 /* check for "register + offset" addressing */ \
1148 if (GET_CODE (xinsn) == PLUS) \
1150 rtx xplus0 = XEXP (xinsn, 0); \
1151 rtx xplus1 = XEXP (xinsn, 1); \
1152 enum rtx_code code0; \
1153 enum rtx_code code1; \
1155 while (GET_CODE (xplus0) == SUBREG) \
1156 xplus0 = SUBREG_REG (xplus0); \
1157 code0 = GET_CODE (xplus0); \
1159 while (GET_CODE (xplus1) == SUBREG) \
1160 xplus1 = SUBREG_REG (xplus1); \
1161 code1 = GET_CODE (xplus1); \
1163 /* swap operands if necessary so the register is first */ \
1164 if (code0 != REG && code1 == REG) \
1166 xplus0 = XEXP (xinsn, 1); \
1167 xplus1 = XEXP (xinsn, 0); \
1168 code0 = GET_CODE (xplus0); \
1169 code1 = GET_CODE (xplus1); \
1172 if (code0 == REG && REG_OK_FOR_BASE_P (xplus0) \
1173 && code1 == CONST_INT \
1174 && xtensa_mem_offset (INTVAL (xplus1), (MODE))) \
1181 /* A C expression that is 1 if the RTX X is a constant which is a
1182 valid address. This is defined to be the same as 'CONSTANT_P (X)',
1183 but rejecting CONST_DOUBLE. */
1184 #define CONSTANT_ADDRESS_P(X) \
1185 ((GET_CODE (X) == LABEL_REF || GET_CODE (X) == SYMBOL_REF \
1186 || GET_CODE (X) == CONST_INT || GET_CODE (X) == HIGH \
1187 || (GET_CODE (X) == CONST)))
1189 /* Nonzero if the constant value X is a legitimate general operand.
1190 It is given that X satisfies CONSTANT_P or is a CONST_DOUBLE. */
1191 #define LEGITIMATE_CONSTANT_P(X) 1
1193 /* A C expression that is nonzero if X is a legitimate immediate
1194 operand on the target machine when generating position independent
1196 #define LEGITIMATE_PIC_OPERAND_P(X) \
1197 ((GET_CODE (X) != SYMBOL_REF || SYMBOL_REF_FLAG (X)) \
1198 && GET_CODE (X) != LABEL_REF \
1199 && GET_CODE (X) != CONST)
1201 /* Tell GCC how to use ADDMI to generate addresses. */
1202 #define LEGITIMIZE_ADDRESS(X, OLDX, MODE, WIN) \
1205 if (GET_CODE (xinsn) == PLUS) \
1207 rtx plus0 = XEXP (xinsn, 0); \
1208 rtx plus1 = XEXP (xinsn, 1); \
1210 if (GET_CODE (plus0) != REG && GET_CODE (plus1) == REG) \
1212 plus0 = XEXP (xinsn, 1); \
1213 plus1 = XEXP (xinsn, 0); \
1216 if (GET_CODE (plus0) == REG \
1217 && GET_CODE (plus1) == CONST_INT \
1218 && !xtensa_mem_offset (INTVAL (plus1), MODE) \
1219 && !xtensa_simm8 (INTVAL (plus1)) \
1220 && xtensa_mem_offset (INTVAL (plus1) & 0xff, MODE) \
1221 && xtensa_simm8x256 (INTVAL (plus1) & ~0xff)) \
1223 rtx temp = gen_reg_rtx (Pmode); \
1224 emit_insn (gen_rtx (SET, Pmode, temp, \
1225 gen_rtx (PLUS, Pmode, plus0, \
1226 GEN_INT (INTVAL (plus1) & ~0xff)))); \
1227 (X) = gen_rtx (PLUS, Pmode, temp, \
1228 GEN_INT (INTVAL (plus1) & 0xff)); \
1235 /* Treat constant-pool references as "mode dependent" since they can
1236 only be accessed with SImode loads. This works around a bug in the
1237 combiner where a constant pool reference is temporarily converted
1238 to an HImode load, which is then assumed to zero-extend based on
1239 our definition of LOAD_EXTEND_OP. This is wrong because the high
1240 bits of a 16-bit value in the constant pool are now sign-extended
1243 #define GO_IF_MODE_DEPENDENT_ADDRESS(ADDR, LABEL) \
1245 if (constantpool_address_p (ADDR)) \
1249 /* Specify the machine mode that this machine uses
1250 for the index in the tablejump instruction. */
1251 #define CASE_VECTOR_MODE (SImode)
1253 /* Define this if the tablejump instruction expects the table
1254 to contain offsets from the address of the table.
1255 Do not define this if the table should contain absolute addresses. */
1256 /* #define CASE_VECTOR_PC_RELATIVE */
1258 /* Define this as 1 if 'char' should by default be signed; else as 0. */
1259 #define DEFAULT_SIGNED_CHAR 0
1261 /* Max number of bytes we can move from memory to memory
1262 in one reasonably fast instruction. */
1264 #define MAX_MOVE_MAX 4
1266 /* Prefer word-sized loads. */
1267 #define SLOW_BYTE_ACCESS 1
1269 /* Xtensa doesn't have any instructions that set integer values based on the
1270 results of comparisons, but the simplification code in the combiner also
1271 uses this macro. The value should be either 1 or -1 to enable some
1272 optimizations in the combiner; I'm not sure which is better for us.
1273 Since we've been using 1 for a while, it should probably stay that way for
1275 #define STORE_FLAG_VALUE 1
1277 /* Shift instructions ignore all but the low-order few bits. */
1278 #define SHIFT_COUNT_TRUNCATED 1
1280 /* Value is 1 if truncating an integer of INPREC bits to OUTPREC bits
1281 is done just by pretending it is already truncated. */
1282 #define TRULY_NOOP_TRUNCATION(OUTPREC, INPREC) 1
1284 /* Specify the machine mode that pointers have.
1285 After generation of rtl, the compiler makes no further distinction
1286 between pointers and any other objects of this machine mode. */
1287 #define Pmode SImode
1289 /* A function address in a call instruction is a word address (for
1290 indexing purposes) so give the MEM rtx a words's mode. */
1291 #define FUNCTION_MODE SImode
1293 /* A C expression that evaluates to true if it is ok to perform a
1294 sibling call to DECL. */
1295 /* TODO: fix this up to allow at least some sibcalls */
1296 #define FUNCTION_OK_FOR_SIBCALL(DECL) 0
1298 /* Xtensa constant costs. */
1299 #define CONST_COSTS(X, CODE, OUTER_CODE) \
1301 switch (OUTER_CODE) \
1304 if (xtensa_simm12b (INTVAL (X))) return 4; \
1307 if (xtensa_simm8 (INTVAL (X))) return 0; \
1308 if (xtensa_simm8x256 (INTVAL (X))) return 0; \
1311 if (xtensa_mask_immediate (INTVAL (X))) return 0; \
1314 if ((INTVAL (X) == 0) || xtensa_b4const (INTVAL (X))) return 0; \
1321 /* no way to tell if X is the 2nd operand so be conservative */ \
1324 if (xtensa_simm12b (INTVAL (X))) return 5; \
1330 case CONST_DOUBLE: \
1333 /* Costs of various Xtensa operations. */
1334 #define RTX_COSTS(X, CODE, OUTER_CODE) \
1338 (GET_MODE_SIZE (GET_MODE (X)) > UNITS_PER_WORD) ? 2 : 1; \
1339 if (memory_address_p (GET_MODE (X), XEXP ((X), 0))) \
1340 return COSTS_N_INSNS (num_words); \
1342 return COSTS_N_INSNS (2*num_words); \
1346 return COSTS_N_INSNS (TARGET_NSA ? 5 : 50); \
1349 return COSTS_N_INSNS ((GET_MODE (X) == DImode) ? 3 : 2); \
1354 if (GET_MODE (X) == DImode) return COSTS_N_INSNS (2); \
1355 return COSTS_N_INSNS (1); \
1360 if (GET_MODE (X) == DImode) return COSTS_N_INSNS (50); \
1361 return COSTS_N_INSNS (1); \
1365 enum machine_mode xmode = GET_MODE (X); \
1366 if (xmode == SFmode) \
1367 return COSTS_N_INSNS (TARGET_HARD_FLOAT ? 1 : 50); \
1368 if (xmode == DFmode) \
1369 return COSTS_N_INSNS (50); \
1370 return COSTS_N_INSNS (4); \
1376 enum machine_mode xmode = GET_MODE (X); \
1377 if (xmode == SFmode) \
1378 return COSTS_N_INSNS (TARGET_HARD_FLOAT ? 1 : 50); \
1379 if (xmode == DFmode || xmode == DImode) \
1380 return COSTS_N_INSNS (50); \
1381 return COSTS_N_INSNS (1); \
1385 return COSTS_N_INSNS ((GET_MODE (X) == DImode) ? 4 : 2); \
1389 enum machine_mode xmode = GET_MODE (X); \
1390 if (xmode == SFmode) \
1391 return COSTS_N_INSNS (TARGET_HARD_FLOAT ? 4 : 50); \
1392 if (xmode == DFmode || xmode == DImode) \
1393 return COSTS_N_INSNS (50); \
1395 return COSTS_N_INSNS (4); \
1397 return COSTS_N_INSNS (16); \
1399 return COSTS_N_INSNS (12); \
1400 return COSTS_N_INSNS (50); \
1406 enum machine_mode xmode = GET_MODE (X); \
1407 if (xmode == SFmode) \
1408 return COSTS_N_INSNS (TARGET_HARD_FLOAT_DIV ? 8 : 50); \
1409 if (xmode == DFmode) \
1410 return COSTS_N_INSNS (50); \
1412 /* fall through */ \
1417 enum machine_mode xmode = GET_MODE (X); \
1418 if (xmode == DImode) \
1419 return COSTS_N_INSNS (50); \
1421 return COSTS_N_INSNS (32); \
1422 return COSTS_N_INSNS (50); \
1426 if (GET_MODE (X) == SFmode) \
1427 return COSTS_N_INSNS (TARGET_HARD_FLOAT_SQRT ? 8 : 50); \
1428 return COSTS_N_INSNS (50); \
1434 return COSTS_N_INSNS (TARGET_MINMAX ? 1 : 50); \
1436 case SIGN_EXTRACT: \
1438 return COSTS_N_INSNS (TARGET_SEXT ? 1 : 2); \
1440 case ZERO_EXTRACT: \
1442 return COSTS_N_INSNS (1);
1445 /* An expression giving the cost of an addressing mode that
1446 contains ADDRESS. */
1447 #define ADDRESS_COST(ADDR) 1
1449 /* A C expression for the cost of moving data from a register in
1450 class FROM to one in class TO. The classes are expressed using
1451 the enumeration values such as 'GENERAL_REGS'. A value of 2 is
1452 the default; other values are interpreted relative to that. */
1453 #define REGISTER_MOVE_COST(MODE, FROM, TO) \
1454 (((FROM) == (TO) && (FROM) != BR_REGS && (TO) != BR_REGS) \
1456 : (reg_class_subset_p ((FROM), AR_REGS) \
1457 && reg_class_subset_p ((TO), AR_REGS) \
1459 : (reg_class_subset_p ((FROM), AR_REGS) \
1460 && (TO) == ACC_REG \
1462 : ((FROM) == ACC_REG \
1463 && reg_class_subset_p ((TO), AR_REGS) \
1467 #define MEMORY_MOVE_COST(MODE, CLASS, IN) 4
1469 #define BRANCH_COST 3
1471 /* Optionally define this if you have added predicates to
1472 'MACHINE.c'. This macro is called within an initializer of an
1473 array of structures. The first field in the structure is the
1474 name of a predicate and the second field is an array of rtl
1475 codes. For each predicate, list all rtl codes that can be in
1476 expressions matched by the predicate. The list should have a
1479 #define PREDICATE_CODES \
1480 {"add_operand", { REG, CONST_INT, SUBREG }}, \
1481 {"arith_operand", { REG, CONST_INT, SUBREG }}, \
1482 {"nonimmed_operand", { REG, SUBREG, MEM }}, \
1483 {"mem_operand", { MEM }}, \
1484 {"mask_operand", { REG, CONST_INT, SUBREG }}, \
1485 {"extui_fldsz_operand", { CONST_INT }}, \
1486 {"sext_fldsz_operand", { CONST_INT }}, \
1487 {"lsbitnum_operand", { CONST_INT }}, \
1488 {"fpmem_offset_operand", { CONST_INT }}, \
1489 {"sext_operand", { REG, SUBREG, MEM }}, \
1490 {"branch_operand", { REG, CONST_INT, SUBREG }}, \
1491 {"ubranch_operand", { REG, CONST_INT, SUBREG }}, \
1492 {"call_insn_operand", { CONST_INT, CONST, SYMBOL_REF, REG }}, \
1493 {"move_operand", { REG, SUBREG, MEM, CONST_INT, CONST_DOUBLE, \
1494 CONST, SYMBOL_REF, LABEL_REF }}, \
1495 {"non_const_move_operand", { REG, SUBREG, MEM }}, \
1496 {"const_float_1_operand", { CONST_DOUBLE }}, \
1497 {"branch_operator", { EQ, NE, LT, GE }}, \
1498 {"ubranch_operator", { LTU, GEU }}, \
1499 {"boolean_operator", { EQ, NE }},
1501 /* Control the assembler format that we output. */
1503 /* How to refer to registers in assembler output.
1504 This sequence is indexed by compiler's hard-register-number (see above). */
1505 #define REGISTER_NAMES \
1507 "a0", "sp", "a2", "a3", "a4", "a5", "a6", "a7", \
1508 "a8", "a9", "a10", "a11", "a12", "a13", "a14", "a15", \
1509 "fp", "argp", "b0", \
1510 "f0", "f1", "f2", "f3", "f4", "f5", "f6", "f7", \
1511 "f8", "f9", "f10", "f11", "f12", "f13", "f14", "f15", \
1515 /* If defined, a C initializer for an array of structures containing a
1516 name and a register number. This macro defines additional names
1517 for hard registers, thus allowing the 'asm' option in declarations
1518 to refer to registers using alternate names. */
1519 #define ADDITIONAL_REGISTER_NAMES \
1521 { "a1", 1 + GP_REG_FIRST } \
1524 #define PRINT_OPERAND(FILE, X, CODE) print_operand (FILE, X, CODE)
1525 #define PRINT_OPERAND_ADDRESS(FILE, ADDR) print_operand_address (FILE, ADDR)
1527 /* Recognize machine-specific patterns that may appear within
1528 constants. Used for PIC-specific UNSPECs. */
1529 #define OUTPUT_ADDR_CONST_EXTRA(STREAM, X, FAIL) \
1531 if (flag_pic && GET_CODE (X) == UNSPEC && XVECLEN ((X), 0) == 1) \
1533 switch (XINT ((X), 1)) \
1536 output_addr_const ((STREAM), XVECEXP ((X), 0, 0)); \
1537 fputs ("@PLT", (STREAM)); \
1549 /* This is how to output the definition of a user-level label named NAME,
1550 such as the label on a static function or variable NAME. */
1551 #define ASM_OUTPUT_LABEL(STREAM, NAME) \
1553 assemble_name (STREAM, NAME); \
1554 fputs (":\n", STREAM); \
1557 /* This is how to output a command to make the user-level label named NAME
1558 defined for reference from other files. */
1559 #define ASM_GLOBALIZE_LABEL(STREAM, NAME) \
1561 fputs ("\t.global\t", STREAM); \
1562 assemble_name (STREAM, NAME); \
1563 fputs ("\n", STREAM); \
1566 /* This says how to define a global common symbol. */
1567 #define ASM_OUTPUT_COMMON(STREAM, NAME, SIZE, ROUNDED) \
1568 xtensa_declare_object (STREAM, NAME, "\n\t.comm\t", ",%u\n", (SIZE))
1570 /* This says how to define a local common symbol (ie, not visible to
1572 #define ASM_OUTPUT_LOCAL(STREAM, NAME, SIZE, ROUNDED) \
1573 xtensa_declare_object (STREAM, NAME, "\n\t.lcomm\t", ",%u\n", (SIZE))
1575 /* This is how to output an element of a case-vector that is absolute. */
1576 #define ASM_OUTPUT_ADDR_VEC_ELT(STREAM, VALUE) \
1577 fprintf (STREAM, "%s%sL%u\n", integer_asm_op (4, TRUE), \
1578 LOCAL_LABEL_PREFIX, VALUE)
1580 /* This is how to output an element of a case-vector that is relative.
1581 This is used for pc-relative code. */
1582 #define ASM_OUTPUT_ADDR_DIFF_ELT(STREAM, BODY, VALUE, REL) \
1584 fprintf (STREAM, "%s%sL%u-%sL%u\n", integer_asm_op (4, TRUE), \
1585 LOCAL_LABEL_PREFIX, (VALUE), \
1586 LOCAL_LABEL_PREFIX, (REL)); \
1589 /* This is how to output an assembler line that says to advance the
1590 location counter to a multiple of 2**LOG bytes. */
1591 #define ASM_OUTPUT_ALIGN(STREAM, LOG) \
1594 fprintf (STREAM, "\t.align\t%d\n", 1 << (LOG)); \
1597 /* Indicate that jump tables go in the text section. This is
1598 necessary when compiling PIC code. */
1599 #define JUMP_TABLES_IN_TEXT_SECTION (flag_pic)
1602 /* Define this macro for the rare case where the RTL needs some sort of
1603 machine-dependent fixup immediately before register allocation is done.
1605 If the stack frame size is too big to fit in the immediate field of
1606 the ENTRY instruction, we need to store the frame size in the
1607 constant pool. However, the code in xtensa_function_prologue runs too
1608 late to be able to add anything to the constant pool. Since the
1609 final frame size isn't known until reload is complete, this seems
1610 like the best place to do it.
1612 There may also be some fixup required if there is an incoming argument
1613 in a7 and the function requires a frame pointer. */
1615 #define MACHINE_DEPENDENT_REORG(INSN) xtensa_reorg (INSN)
1618 /* Define the strings to put out for each section in the object file. */
1619 #define TEXT_SECTION_ASM_OP "\t.text" /* instructions */
1620 #define DATA_SECTION_ASM_OP "\t.data" /* large data */
1623 /* Define output to appear before the constant pool. If the function
1624 has been assigned to a specific ELF section, or if it goes into a
1625 unique section, set the name of that section to be the literal
1627 #define ASM_OUTPUT_POOL_PROLOGUE(FILE, FUNNAME, FUNDECL, SIZE) \
1630 resolve_unique_section ((FUNDECL), 0, flag_function_sections); \
1631 fnsection = DECL_SECTION_NAME (FUNDECL); \
1632 if (fnsection != NULL_TREE) \
1634 const char *fnsectname = TREE_STRING_POINTER (fnsection); \
1635 fprintf (FILE, "\t.begin\tliteral_prefix %s\n", \
1636 strcmp (fnsectname, ".text") ? fnsectname : ""); \
1640 function_section (FUNDECL); \
1641 fprintf (FILE, "\t.literal_position\n"); \
1646 /* Define code to write out the ".end literal_prefix" directive for a
1647 function in a special section. This is appended to the standard ELF
1648 code for ASM_DECLARE_FUNCTION_SIZE. */
1649 #define XTENSA_DECLARE_FUNCTION_SIZE(FILE, FNAME, DECL) \
1650 if (DECL_SECTION_NAME (DECL) != NULL_TREE) \
1651 fprintf (FILE, "\t.end\tliteral_prefix\n")
1653 /* A C statement (with or without semicolon) to output a constant in
1654 the constant pool, if it needs special treatment. */
1655 #define ASM_OUTPUT_SPECIAL_POOL_ENTRY(FILE, X, MODE, ALIGN, LABELNO, JUMPTO) \
1657 xtensa_output_literal (FILE, X, MODE, LABELNO); \
1661 /* Store in OUTPUT a string (made with alloca) containing
1662 an assembler-name for a local static variable named NAME.
1663 LABELNO is an integer which is different for each call. */
1664 #define ASM_FORMAT_PRIVATE_NAME(OUTPUT, NAME, LABELNO) \
1666 (OUTPUT) = (char *) alloca (strlen (NAME) + 10); \
1667 sprintf ((OUTPUT), "%s.%u", (NAME), (LABELNO)); \
1670 /* How to start an assembler comment. */
1671 #define ASM_COMMENT_START "#"
1673 /* Exception handling TODO!! */
1674 #define DWARF_UNWIND_INFO 0
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