1 /* Definitions of Tensilica's Xtensa target machine for GNU compiler.
2 Copyright 2001,2002 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 ()
195 /* Target CPU builtins. */
196 #define TARGET_CPU_CPP_BUILTINS() \
198 builtin_assert ("cpu=xtensa"); \
199 builtin_assert ("machine=xtensa"); \
200 builtin_define ("__XTENSA__"); \
201 builtin_define (TARGET_BIG_ENDIAN ? "__XTENSA_EB__" : "__XTENSA_EL__"); \
202 if (!TARGET_HARD_FLOAT) \
203 builtin_define ("__XTENSA_SOFT_FLOAT__"); \
206 builtin_define ("__PIC__"); \
207 builtin_define ("__pic__"); \
211 /* Define this to set the endianness to use in libgcc2.c, which can
212 not depend on target_flags. */
213 #define LIBGCC2_WORDS_BIG_ENDIAN XCHAL_HAVE_BE
215 /* Show we can debug even without a frame pointer. */
216 #define CAN_DEBUG_WITHOUT_FP
219 /* Target machine storage layout */
221 /* Define this if most significant bit is lowest numbered
222 in instructions that operate on numbered bit-fields. */
223 #define BITS_BIG_ENDIAN (TARGET_BIG_ENDIAN != 0)
225 /* Define this if most significant byte of a word is the lowest numbered. */
226 #define BYTES_BIG_ENDIAN (TARGET_BIG_ENDIAN != 0)
228 /* Define this if most significant word of a multiword number is the lowest. */
229 #define WORDS_BIG_ENDIAN (TARGET_BIG_ENDIAN != 0)
231 #define MAX_BITS_PER_WORD 32
233 /* Width of a word, in units (bytes). */
234 #define UNITS_PER_WORD 4
235 #define MIN_UNITS_PER_WORD 4
237 /* Width of a floating point register. */
238 #define UNITS_PER_FPREG 4
240 /* Size in bits of various types on the target machine. */
241 #define INT_TYPE_SIZE 32
242 #define SHORT_TYPE_SIZE 16
243 #define LONG_TYPE_SIZE 32
244 #define MAX_LONG_TYPE_SIZE 32
245 #define LONG_LONG_TYPE_SIZE 64
246 #define FLOAT_TYPE_SIZE 32
247 #define DOUBLE_TYPE_SIZE 64
248 #define LONG_DOUBLE_TYPE_SIZE 64
250 /* Allocation boundary (in *bits*) for storing pointers in memory. */
251 #define POINTER_BOUNDARY 32
253 /* Allocation boundary (in *bits*) for storing arguments in argument list. */
254 #define PARM_BOUNDARY 32
256 /* Allocation boundary (in *bits*) for the code of a function. */
257 #define FUNCTION_BOUNDARY 32
259 /* Alignment of field after 'int : 0' in a structure. */
260 #define EMPTY_FIELD_BOUNDARY 32
262 /* Every structure's size must be a multiple of this. */
263 #define STRUCTURE_SIZE_BOUNDARY 8
265 /* There is no point aligning anything to a rounder boundary than this. */
266 #define BIGGEST_ALIGNMENT 128
268 /* Set this nonzero if move instructions will actually fail to work
269 when given unaligned data. */
270 #define STRICT_ALIGNMENT 1
272 /* Promote integer modes smaller than a word to SImode. Set UNSIGNEDP
273 for QImode, because there is no 8-bit load from memory with sign
274 extension. Otherwise, leave UNSIGNEDP alone, since Xtensa has 16-bit
275 loads both with and without sign extension. */
276 #define PROMOTE_MODE(MODE, UNSIGNEDP, TYPE) \
278 if (GET_MODE_CLASS (MODE) == MODE_INT \
279 && GET_MODE_SIZE (MODE) < UNITS_PER_WORD) \
281 if ((MODE) == QImode) \
287 /* The promotion described by `PROMOTE_MODE' should also be done for
288 outgoing function arguments. */
289 #define PROMOTE_FUNCTION_ARGS
291 /* The promotion described by `PROMOTE_MODE' should also be done for
292 the return value of functions. Note: `FUNCTION_VALUE' must perform
293 the same promotions done by `PROMOTE_MODE'. */
294 #define PROMOTE_FUNCTION_RETURN
296 /* Imitate the way many other C compilers handle alignment of
297 bitfields and the structures that contain them. */
298 #define PCC_BITFIELD_TYPE_MATTERS 1
300 /* Align string constants and constructors to at least a word boundary.
301 The typical use of this macro is to increase alignment for string
302 constants to be word aligned so that 'strcpy' calls that copy
303 constants can be done inline. */
304 #define CONSTANT_ALIGNMENT(EXP, ALIGN) \
305 ((TREE_CODE (EXP) == STRING_CST || TREE_CODE (EXP) == CONSTRUCTOR) \
306 && (ALIGN) < BITS_PER_WORD \
310 /* Align arrays, unions and records to at least a word boundary.
311 One use of this macro is to increase alignment of medium-size
312 data to make it all fit in fewer cache lines. Another is to
313 cause character arrays to be word-aligned so that 'strcpy' calls
314 that copy constants to character arrays can be done inline. */
315 #undef DATA_ALIGNMENT
316 #define DATA_ALIGNMENT(TYPE, ALIGN) \
317 ((((ALIGN) < BITS_PER_WORD) \
318 && (TREE_CODE (TYPE) == ARRAY_TYPE \
319 || TREE_CODE (TYPE) == UNION_TYPE \
320 || TREE_CODE (TYPE) == RECORD_TYPE)) ? BITS_PER_WORD : (ALIGN))
322 /* An argument declared as 'char' or 'short' in a prototype should
323 actually be passed as an 'int'. */
324 #define PROMOTE_PROTOTYPES 1
326 /* Operations between registers always perform the operation
327 on the full register even if a narrower mode is specified. */
328 #define WORD_REGISTER_OPERATIONS
330 /* Xtensa loads are zero-extended by default. */
331 #define LOAD_EXTEND_OP(MODE) ZERO_EXTEND
333 /* Standard register usage. */
335 /* Number of actual hardware registers.
336 The hardware registers are assigned numbers for the compiler
337 from 0 to just below FIRST_PSEUDO_REGISTER.
338 All registers that the compiler knows about must be given numbers,
339 even those that are not normally considered general registers.
341 The fake frame pointer and argument pointer will never appear in
342 the generated code, since they will always be eliminated and replaced
343 by either the stack pointer or the hard frame pointer.
345 0 - 15 AR[0] - AR[15]
346 16 FRAME_POINTER (fake = initial sp)
347 17 ARG_POINTER (fake = initial sp + framesize)
348 18 BR[0] for floating-point CC
349 19 - 34 FR[0] - FR[15]
350 35 MAC16 accumulator */
352 #define FIRST_PSEUDO_REGISTER 36
354 /* Return the stabs register number to use for REGNO. */
355 #define DBX_REGISTER_NUMBER(REGNO) xtensa_dbx_register_number (REGNO)
357 /* 1 for registers that have pervasive standard uses
358 and are not available for the register allocator. */
359 #define FIXED_REGISTERS \
361 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, \
363 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, \
367 /* 1 for registers not available across function calls.
368 These must include the FIXED_REGISTERS and also any
369 registers that can be used without being saved.
370 The latter must include the registers where values are returned
371 and the register where structure-value addresses are passed.
372 Aside from that, you can include as many other registers as you like. */
373 #define CALL_USED_REGISTERS \
375 1, 1, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1, \
377 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, \
381 /* For non-leaf procedures on Xtensa processors, the allocation order
382 is as specified below by REG_ALLOC_ORDER. For leaf procedures, we
383 want to use the lowest numbered registers first to minimize
384 register window overflows. However, local-alloc is not smart
385 enough to consider conflicts with incoming arguments. If an
386 incoming argument in a2 is live throughout the function and
387 local-alloc decides to use a2, then the incoming argument must
388 either be spilled or copied to another register. To get around
389 this, we define ORDER_REGS_FOR_LOCAL_ALLOC to redefine
390 reg_alloc_order for leaf functions such that lowest numbered
391 registers are used first with the exception that the incoming
392 argument registers are not used until after other register choices
393 have been exhausted. */
395 #define REG_ALLOC_ORDER \
396 { 8, 9, 10, 11, 12, 13, 14, 15, 7, 6, 5, 4, 3, 2, \
398 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, \
403 #define ORDER_REGS_FOR_LOCAL_ALLOC order_regs_for_local_alloc ()
405 /* For Xtensa, the only point of this is to prevent GCC from otherwise
406 giving preference to call-used registers. To minimize window
407 overflows for the AR registers, we want to give preference to the
408 lower-numbered AR registers. For other register files, which are
409 not windowed, we still prefer call-used registers, if there are any. */
410 extern const char xtensa_leaf_regs[FIRST_PSEUDO_REGISTER];
411 #define LEAF_REGISTERS xtensa_leaf_regs
413 /* For Xtensa, no remapping is necessary, but this macro must be
414 defined if LEAF_REGISTERS is defined. */
415 #define LEAF_REG_REMAP(REGNO) (REGNO)
417 /* this must be declared if LEAF_REGISTERS is set */
418 extern int leaf_function;
420 /* Internal macros to classify a register number. */
422 /* 16 address registers + fake registers */
423 #define GP_REG_FIRST 0
424 #define GP_REG_LAST 17
425 #define GP_REG_NUM (GP_REG_LAST - GP_REG_FIRST + 1)
427 /* Coprocessor registers */
428 #define BR_REG_FIRST 18
429 #define BR_REG_LAST 18
430 #define BR_REG_NUM (BR_REG_LAST - BR_REG_FIRST + 1)
432 /* 16 floating-point registers */
433 #define FP_REG_FIRST 19
434 #define FP_REG_LAST 34
435 #define FP_REG_NUM (FP_REG_LAST - FP_REG_FIRST + 1)
437 /* MAC16 accumulator */
438 #define ACC_REG_FIRST 35
439 #define ACC_REG_LAST 35
440 #define ACC_REG_NUM (ACC_REG_LAST - ACC_REG_FIRST + 1)
442 #define GP_REG_P(REGNO) ((unsigned) ((REGNO) - GP_REG_FIRST) < GP_REG_NUM)
443 #define BR_REG_P(REGNO) ((unsigned) ((REGNO) - BR_REG_FIRST) < BR_REG_NUM)
444 #define FP_REG_P(REGNO) ((unsigned) ((REGNO) - FP_REG_FIRST) < FP_REG_NUM)
445 #define ACC_REG_P(REGNO) ((unsigned) ((REGNO) - ACC_REG_FIRST) < ACC_REG_NUM)
447 /* Return number of consecutive hard regs needed starting at reg REGNO
448 to hold something of mode MODE. */
449 #define HARD_REGNO_NREGS(REGNO, MODE) \
450 (FP_REG_P (REGNO) ? \
451 ((GET_MODE_SIZE (MODE) + UNITS_PER_FPREG - 1) / UNITS_PER_FPREG) : \
452 ((GET_MODE_SIZE (MODE) + UNITS_PER_WORD - 1) / UNITS_PER_WORD))
454 /* Value is 1 if hard register REGNO can hold a value of machine-mode
456 extern char xtensa_hard_regno_mode_ok[][FIRST_PSEUDO_REGISTER];
458 #define HARD_REGNO_MODE_OK(REGNO, MODE) \
459 xtensa_hard_regno_mode_ok[(int) (MODE)][(REGNO)]
461 /* Value is 1 if it is a good idea to tie two pseudo registers
462 when one has mode MODE1 and one has mode MODE2.
463 If HARD_REGNO_MODE_OK could produce different values for MODE1 and MODE2,
464 for any hard reg, then this must be 0 for correct output. */
465 #define MODES_TIEABLE_P(MODE1, MODE2) \
466 ((GET_MODE_CLASS (MODE1) == MODE_FLOAT || \
467 GET_MODE_CLASS (MODE1) == MODE_COMPLEX_FLOAT) \
468 == (GET_MODE_CLASS (MODE2) == MODE_FLOAT || \
469 GET_MODE_CLASS (MODE2) == MODE_COMPLEX_FLOAT))
471 /* Register to use for pushing function arguments. */
472 #define STACK_POINTER_REGNUM (GP_REG_FIRST + 1)
474 /* Base register for access to local variables of the function. */
475 #define HARD_FRAME_POINTER_REGNUM (GP_REG_FIRST + 7)
477 /* The register number of the frame pointer register, which is used to
478 access automatic variables in the stack frame. For Xtensa, this
479 register never appears in the output. It is always eliminated to
480 either the stack pointer or the hard frame pointer. */
481 #define FRAME_POINTER_REGNUM (GP_REG_FIRST + 16)
483 /* Value should be nonzero if functions must have frame pointers.
484 Zero means the frame pointer need not be set up (and parms
485 may be accessed via the stack pointer) in functions that seem suitable.
486 This is computed in 'reload', in reload1.c. */
487 #define FRAME_POINTER_REQUIRED xtensa_frame_pointer_required ()
489 /* Base register for access to arguments of the function. */
490 #define ARG_POINTER_REGNUM (GP_REG_FIRST + 17)
492 /* If the static chain is passed in memory, these macros provide rtx
493 giving 'mem' expressions that denote where they are stored.
494 'STATIC_CHAIN' and 'STATIC_CHAIN_INCOMING' give the locations as
495 seen by the calling and called functions, respectively. */
497 #define STATIC_CHAIN \
498 gen_rtx_MEM (Pmode, plus_constant (stack_pointer_rtx, -5 * UNITS_PER_WORD))
500 #define STATIC_CHAIN_INCOMING \
501 gen_rtx_MEM (Pmode, plus_constant (arg_pointer_rtx, -5 * UNITS_PER_WORD))
503 /* For now we don't try to use the full set of boolean registers. Without
504 software pipelining of FP operations, there's not much to gain and it's
505 a real pain to get them reloaded. */
506 #define FPCC_REGNUM (BR_REG_FIRST + 0)
508 /* Pass structure value address as an "invisible" first argument. */
509 #define STRUCT_VALUE 0
511 /* It is as good or better to call a constant function address than to
512 call an address kept in a register. */
513 #define NO_FUNCTION_CSE 1
515 /* It is as good or better for a function to call itself with an
516 explicit address than to call an address kept in a register. */
517 #define NO_RECURSIVE_FUNCTION_CSE 1
519 /* Xtensa processors have "register windows". GCC does not currently
520 take advantage of the possibility for variable-sized windows; instead,
521 we use a fixed window size of 8. */
523 #define INCOMING_REGNO(OUT) \
524 ((GP_REG_P (OUT) && \
525 ((unsigned) ((OUT) - GP_REG_FIRST) >= WINDOW_SIZE)) ? \
526 (OUT) - WINDOW_SIZE : (OUT))
528 #define OUTGOING_REGNO(IN) \
530 ((unsigned) ((IN) - GP_REG_FIRST) < WINDOW_SIZE)) ? \
531 (IN) + WINDOW_SIZE : (IN))
534 /* Define the classes of registers for register constraints in the
535 machine description. */
538 NO_REGS, /* no registers in set */
539 BR_REGS, /* coprocessor boolean registers */
540 FP_REGS, /* floating point registers */
541 ACC_REG, /* MAC16 accumulator */
542 SP_REG, /* sp register (aka a1) */
543 RL_REGS, /* preferred reload regs (not sp or fp) */
544 GR_REGS, /* integer registers except sp */
545 AR_REGS, /* all integer registers */
546 ALL_REGS, /* all registers */
547 LIM_REG_CLASSES /* max value + 1 */
550 #define N_REG_CLASSES (int) LIM_REG_CLASSES
552 #define GENERAL_REGS AR_REGS
554 /* An initializer containing the names of the register classes as C
555 string constants. These names are used in writing some of the
557 #define REG_CLASS_NAMES \
570 /* Contents of the register classes. The Nth integer specifies the
571 contents of class N. The way the integer MASK is interpreted is
572 that register R is in the class if 'MASK & (1 << R)' is 1. */
573 #define REG_CLASS_CONTENTS \
575 { 0x00000000, 0x00000000 }, /* no registers */ \
576 { 0x00040000, 0x00000000 }, /* coprocessor boolean registers */ \
577 { 0xfff80000, 0x00000007 }, /* floating-point registers */ \
578 { 0x00000000, 0x00000008 }, /* MAC16 accumulator */ \
579 { 0x00000002, 0x00000000 }, /* stack pointer register */ \
580 { 0x0000ff7d, 0x00000000 }, /* preferred reload registers */ \
581 { 0x0000fffd, 0x00000000 }, /* general-purpose registers */ \
582 { 0x0003ffff, 0x00000000 }, /* integer registers */ \
583 { 0xffffffff, 0x0000000f } /* all registers */ \
586 /* A C expression whose value is a register class containing hard
587 register REGNO. In general there is more that one such class;
588 choose a class which is "minimal", meaning that no smaller class
589 also contains the register. */
590 extern const enum reg_class xtensa_regno_to_class[FIRST_PSEUDO_REGISTER];
592 #define REGNO_REG_CLASS(REGNO) xtensa_regno_to_class[ (REGNO) ]
594 /* Use the Xtensa AR register file for base registers.
595 No index registers. */
596 #define BASE_REG_CLASS AR_REGS
597 #define INDEX_REG_CLASS NO_REGS
599 /* SMALL_REGISTER_CLASSES is required for Xtensa, because all of the
600 16 AR registers may be explicitly used in the RTL, as either
601 incoming or outgoing arguments. */
602 #define SMALL_REGISTER_CLASSES 1
605 /* REGISTER AND CONSTANT CLASSES */
607 /* Get reg_class from a letter such as appears in the machine
610 Available letters: a-f,h,j-l,q,t-z,A-D,W,Y-Z
612 DEFINED REGISTER CLASSES:
614 'a' general-purpose registers except sp
616 'D' general-purpose registers (only if density option enabled)
617 'd' general-purpose registers, including sp (only if density enabled)
618 'A' MAC16 accumulator (only if MAC16 option enabled)
619 'B' general-purpose registers (only if sext instruction enabled)
620 'C' general-purpose registers (only if mul16 option enabled)
621 'b' coprocessor boolean registers
622 'f' floating-point registers
625 extern enum reg_class xtensa_char_to_class[256];
627 #define REG_CLASS_FROM_LETTER(C) xtensa_char_to_class[ (int) (C) ]
629 /* The letters I, J, K, L, M, N, O, and P in a register constraint
630 string can be used to stand for particular ranges of immediate
631 operands. This macro defines what the ranges are. C is the
632 letter, and VALUE is a constant value. Return 1 if VALUE is
633 in the range specified by C.
637 I = 12-bit signed immediate for movi
638 J = 8-bit signed immediate for addi
639 K = 4-bit value in (b4const U {0})
640 L = 4-bit value in b4constu
641 M = 7-bit value in simm7
642 N = 8-bit unsigned immediate shifted left by 8 bits for addmi
643 O = 4-bit value in ai4const
644 P = valid immediate mask value for extui */
646 #define CONST_OK_FOR_LETTER_P(VALUE, C) \
647 ((C) == 'I' ? (xtensa_simm12b (VALUE)) \
648 : (C) == 'J' ? (xtensa_simm8 (VALUE)) \
649 : (C) == 'K' ? (((VALUE) == 0) || xtensa_b4const (VALUE)) \
650 : (C) == 'L' ? (xtensa_b4constu (VALUE)) \
651 : (C) == 'M' ? (xtensa_simm7 (VALUE)) \
652 : (C) == 'N' ? (xtensa_simm8x256 (VALUE)) \
653 : (C) == 'O' ? (xtensa_ai4const (VALUE)) \
654 : (C) == 'P' ? (xtensa_mask_immediate (VALUE)) \
658 /* Similar, but for floating constants, and defining letters G and H.
659 Here VALUE is the CONST_DOUBLE rtx itself. */
660 #define CONST_DOUBLE_OK_FOR_LETTER_P(VALUE, C) (0)
663 /* Other letters can be defined in a machine-dependent fashion to
664 stand for particular classes of registers or other arbitrary
667 R = memory that can be accessed with a 4-bit unsigned offset
668 S = memory where the second word can be addressed with a 4-bit offset
669 T = memory in a constant pool (addressable with a pc-relative load)
670 U = memory *NOT* in a constant pool
672 The offset range should not be checked here (except to distinguish
673 denser versions of the instructions for which more general versions
674 are available). Doing so leads to problems in reloading: an
675 argptr-relative address may become invalid when the phony argptr is
676 eliminated in favor of the stack pointer (the offset becomes too
677 large to fit in the instruction's immediate field); a reload is
678 generated to fix this but the RTL is not immediately updated; in
679 the meantime, the constraints are checked and none match. The
680 solution seems to be to simply skip the offset check here. The
681 address will be checked anyway because of the code in
682 GO_IF_LEGITIMATE_ADDRESS. */
684 #define EXTRA_CONSTRAINT(OP, CODE) \
685 ((GET_CODE (OP) != MEM) ? \
686 ((CODE) >= 'R' && (CODE) <= 'U' \
687 && reload_in_progress && GET_CODE (OP) == REG \
688 && REGNO (OP) >= FIRST_PSEUDO_REGISTER) \
689 : ((CODE) == 'R') ? smalloffset_mem_p (OP) \
690 : ((CODE) == 'S') ? smalloffset_double_mem_p (OP) \
691 : ((CODE) == 'T') ? constantpool_mem_p (OP) \
692 : ((CODE) == 'U') ? !constantpool_mem_p (OP) \
695 #define PREFERRED_RELOAD_CLASS(X, CLASS) \
696 xtensa_preferred_reload_class (X, CLASS, 0)
698 #define PREFERRED_OUTPUT_RELOAD_CLASS(X, CLASS) \
699 xtensa_preferred_reload_class (X, CLASS, 1)
701 #define SECONDARY_INPUT_RELOAD_CLASS(CLASS, MODE, X) \
702 xtensa_secondary_reload_class (CLASS, MODE, X, 0)
704 #define SECONDARY_OUTPUT_RELOAD_CLASS(CLASS, MODE, X) \
705 xtensa_secondary_reload_class (CLASS, MODE, X, 1)
707 /* Return the maximum number of consecutive registers
708 needed to represent mode MODE in a register of class CLASS. */
709 #define CLASS_UNITS(mode, size) \
710 ((GET_MODE_SIZE (mode) + (size) - 1) / (size))
712 #define CLASS_MAX_NREGS(CLASS, MODE) \
713 (CLASS_UNITS (MODE, UNITS_PER_WORD))
716 /* Stack layout; function entry, exit and calling. */
718 #define STACK_GROWS_DOWNWARD
720 /* Offset within stack frame to start allocating local variables at. */
721 #define STARTING_FRAME_OFFSET \
722 current_function_outgoing_args_size
724 /* The ARG_POINTER and FRAME_POINTER are not real Xtensa registers, so
725 they are eliminated to either the stack pointer or hard frame pointer. */
726 #define ELIMINABLE_REGS \
727 {{ ARG_POINTER_REGNUM, STACK_POINTER_REGNUM}, \
728 { ARG_POINTER_REGNUM, HARD_FRAME_POINTER_REGNUM}, \
729 { FRAME_POINTER_REGNUM, STACK_POINTER_REGNUM}, \
730 { FRAME_POINTER_REGNUM, HARD_FRAME_POINTER_REGNUM}}
732 #define CAN_ELIMINATE(FROM, TO) 1
734 /* Specify the initial difference between the specified pair of registers. */
735 #define INITIAL_ELIMINATION_OFFSET(FROM, TO, OFFSET) \
737 compute_frame_size (get_frame_size ()); \
738 if ((FROM) == FRAME_POINTER_REGNUM) \
740 else if ((FROM) == ARG_POINTER_REGNUM) \
741 (OFFSET) = xtensa_current_frame_size; \
746 /* If defined, the maximum amount of space required for outgoing
747 arguments will be computed and placed into the variable
748 'current_function_outgoing_args_size'. No space will be pushed
749 onto the stack for each call; instead, the function prologue
750 should increase the stack frame size by this amount. */
751 #define ACCUMULATE_OUTGOING_ARGS 1
753 /* Offset from the argument pointer register to the first argument's
754 address. On some machines it may depend on the data type of the
755 function. If 'ARGS_GROW_DOWNWARD', this is the offset to the
756 location above the first argument's address. */
757 #define FIRST_PARM_OFFSET(FNDECL) 0
759 /* Align stack frames on 128 bits for Xtensa. This is necessary for
760 128-bit datatypes defined in TIE (e.g., for Vectra). */
761 #define STACK_BOUNDARY 128
763 /* Functions do not pop arguments off the stack. */
764 #define RETURN_POPS_ARGS(FUNDECL, FUNTYPE, SIZE) 0
766 /* Use a fixed register window size of 8. */
767 #define WINDOW_SIZE 8
769 /* Symbolic macros for the registers used to return integer, floating
770 point, and values of coprocessor and user-defined modes. */
771 #define GP_RETURN (GP_REG_FIRST + 2 + WINDOW_SIZE)
772 #define GP_OUTGOING_RETURN (GP_REG_FIRST + 2)
774 /* Symbolic macros for the first/last argument registers. */
775 #define GP_ARG_FIRST (GP_REG_FIRST + 2)
776 #define GP_ARG_LAST (GP_REG_FIRST + 7)
777 #define GP_OUTGOING_ARG_FIRST (GP_REG_FIRST + 2 + WINDOW_SIZE)
778 #define GP_OUTGOING_ARG_LAST (GP_REG_FIRST + 7 + WINDOW_SIZE)
780 #define MAX_ARGS_IN_REGISTERS 6
782 /* Don't worry about compatibility with PCC. */
783 #define DEFAULT_PCC_STRUCT_RETURN 0
785 /* For Xtensa, up to 4 words can be returned in registers. (It would
786 have been nice to allow up to 6 words in registers but GCC cannot
787 support that. The return value must be given one of the standard
788 MODE_INT modes, and there is no 6 word mode. Instead, if we try to
789 return a 6 word structure, GCC selects the next biggest mode
790 (OImode, 8 words) and then the register allocator fails because
791 there is no 8-register group beginning with a10.) */
792 #define RETURN_IN_MEMORY(TYPE) \
793 ((unsigned HOST_WIDE_INT) int_size_in_bytes (TYPE) > 4 * UNITS_PER_WORD)
795 /* Define how to find the value returned by a library function
796 assuming the value has mode MODE. Because we have defined
797 PROMOTE_FUNCTION_RETURN, we have to perform the same promotions as
799 #define XTENSA_LIBCALL_VALUE(MODE, OUTGOINGP) \
800 gen_rtx_REG ((GET_MODE_CLASS (MODE) == MODE_INT \
801 && GET_MODE_SIZE (MODE) < UNITS_PER_WORD) \
803 OUTGOINGP ? GP_OUTGOING_RETURN : GP_RETURN)
805 #define LIBCALL_VALUE(MODE) \
806 XTENSA_LIBCALL_VALUE ((MODE), 0)
808 #define LIBCALL_OUTGOING_VALUE(MODE) \
809 XTENSA_LIBCALL_VALUE ((MODE), 1)
811 /* Define how to find the value returned by a function.
812 VALTYPE is the data type of the value (as a tree).
813 If the precise function being called is known, FUNC is its FUNCTION_DECL;
814 otherwise, FUNC is 0. */
815 #define XTENSA_FUNCTION_VALUE(VALTYPE, FUNC, OUTGOINGP) \
816 gen_rtx_REG ((INTEGRAL_TYPE_P (VALTYPE) \
817 && TYPE_PRECISION (VALTYPE) < BITS_PER_WORD) \
818 ? SImode: TYPE_MODE (VALTYPE), \
819 OUTGOINGP ? GP_OUTGOING_RETURN : GP_RETURN)
821 #define FUNCTION_VALUE(VALTYPE, FUNC) \
822 XTENSA_FUNCTION_VALUE (VALTYPE, FUNC, 0)
824 #define FUNCTION_OUTGOING_VALUE(VALTYPE, FUNC) \
825 XTENSA_FUNCTION_VALUE (VALTYPE, FUNC, 1)
827 /* A C expression that is nonzero if REGNO is the number of a hard
828 register in which the values of called function may come back. A
829 register whose use for returning values is limited to serving as
830 the second of a pair (for a value of type 'double', say) need not
831 be recognized by this macro. If the machine has register windows,
832 so that the caller and the called function use different registers
833 for the return value, this macro should recognize only the caller's
835 #define FUNCTION_VALUE_REGNO_P(N) \
838 /* A C expression that is nonzero if REGNO is the number of a hard
839 register in which function arguments are sometimes passed. This
840 does *not* include implicit arguments such as the static chain and
841 the structure-value address. On many machines, no registers can be
842 used for this purpose since all function arguments are pushed on
844 #define FUNCTION_ARG_REGNO_P(N) \
845 ((N) >= GP_OUTGOING_ARG_FIRST && (N) <= GP_OUTGOING_ARG_LAST)
847 /* Define a data type for recording info about an argument list
848 during the scan of that argument list. This data type should
849 hold all necessary information about the function itself
850 and about the args processed so far, enough to enable macros
851 such as FUNCTION_ARG to determine where the next arg should go. */
852 typedef struct xtensa_args {
853 int arg_words; /* # total words the arguments take */
856 /* Initialize a variable CUM of type CUMULATIVE_ARGS
857 for a call to a function whose data type is FNTYPE.
858 For a library call, FNTYPE is 0. */
859 #define INIT_CUMULATIVE_ARGS(CUM, FNTYPE, LIBNAME, INDIRECT) \
860 init_cumulative_args (&CUM, FNTYPE, LIBNAME)
862 #define INIT_CUMULATIVE_INCOMING_ARGS(CUM, FNTYPE, LIBNAME) \
863 init_cumulative_args (&CUM, FNTYPE, LIBNAME)
865 /* Update the data in CUM to advance over an argument
866 of mode MODE and data type TYPE.
867 (TYPE is null for libcalls where that information may not be available.) */
868 #define FUNCTION_ARG_ADVANCE(CUM, MODE, TYPE, NAMED) \
869 function_arg_advance (&CUM, MODE, TYPE)
871 #define FUNCTION_ARG(CUM, MODE, TYPE, NAMED) \
872 function_arg (&CUM, MODE, TYPE, FALSE)
874 #define FUNCTION_INCOMING_ARG(CUM, MODE, TYPE, NAMED) \
875 function_arg (&CUM, MODE, TYPE, TRUE)
877 /* Arguments are never passed partly in memory and partly in registers. */
878 #define FUNCTION_ARG_PARTIAL_NREGS(CUM, MODE, TYPE, NAMED) (0)
880 /* Specify function argument alignment. */
881 #define FUNCTION_ARG_BOUNDARY(MODE, TYPE) \
883 ? (TYPE_ALIGN (TYPE) <= PARM_BOUNDARY \
885 : TYPE_ALIGN (TYPE)) \
886 : (GET_MODE_ALIGNMENT (MODE) <= PARM_BOUNDARY \
888 : GET_MODE_ALIGNMENT (MODE)))
891 /* Nonzero if we do not know how to pass TYPE solely in registers.
892 We cannot do so in the following cases:
894 - if the type has variable size
895 - if the type is marked as addressable (it is required to be constructed
898 This differs from the default in that it does not check if the padding
899 and mode of the type are such that a copy into a register would put it
900 into the wrong part of the register. */
902 #define MUST_PASS_IN_STACK(MODE, TYPE) \
904 && (TREE_CODE (TYPE_SIZE (TYPE)) != INTEGER_CST \
905 || TREE_ADDRESSABLE (TYPE)))
907 /* Profiling Xtensa code is typically done with the built-in profiling
908 feature of Tensilica's instruction set simulator, which does not
909 require any compiler support. Profiling code on a real (i.e.,
910 non-simulated) Xtensa processor is currently only supported by
911 GNU/Linux with glibc. The glibc version of _mcount doesn't require
912 counter variables. The _mcount function needs the current PC and
913 the current return address to identify an arc in the call graph.
914 Pass the current return address as the first argument; the current
915 PC is available as a0 in _mcount's register window. Both of these
916 values contain window size information in the two most significant
917 bits; we assume that _mcount will mask off those bits. The call to
918 _mcount uses a window size of 8 to make sure that it doesn't clobber
919 any incoming argument values. */
921 #define NO_PROFILE_COUNTERS
923 #define FUNCTION_PROFILER(FILE, LABELNO) \
925 fprintf (FILE, "\t%s\ta10, a0\n", TARGET_DENSITY ? "mov.n" : "mov"); \
928 fprintf (FILE, "\tmovi\ta8, _mcount@PLT\n"); \
929 fprintf (FILE, "\tcallx8\ta8\n"); \
932 fprintf (FILE, "\tcall8\t_mcount\n"); \
935 /* Stack pointer value doesn't matter at exit. */
936 #define EXIT_IGNORE_STACK 1
938 /* A C statement to output, on the stream FILE, assembler code for a
939 block of data that contains the constant parts of a trampoline.
940 This code should not include a label--the label is taken care of
943 For Xtensa, the trampoline must perform an entry instruction with a
944 minimal stack frame in order to get some free registers. Once the
945 actual call target is known, the proper stack frame size is extracted
946 from the entry instruction at the target and the current frame is
947 adjusted to match. The trampoline then transfers control to the
948 instruction following the entry at the target. Note: this assumes
949 that the target begins with an entry instruction. */
951 /* minimum frame = reg save area (4 words) plus static chain (1 word)
952 and the total number of words must be a multiple of 128 bits */
953 #define MIN_FRAME_SIZE (8 * UNITS_PER_WORD)
955 #define TRAMPOLINE_TEMPLATE(STREAM) \
957 fprintf (STREAM, "\t.begin no-generics\n"); \
958 fprintf (STREAM, "\tentry\tsp, %d\n", MIN_FRAME_SIZE); \
960 /* GCC isn't prepared to deal with data at the beginning of the \
961 trampoline, and the Xtensa l32r instruction requires that the \
962 constant pool be located before the code. We put the constant \
963 pool in the middle of the trampoline and jump around it. */ \
965 fprintf (STREAM, "\tj\t.Lskipconsts\n"); \
966 fprintf (STREAM, "\t.align\t4\n"); \
967 fprintf (STREAM, ".Lfnaddr:%s0\n", integer_asm_op (4, TRUE)); \
968 fprintf (STREAM, ".Lchainval:%s0\n", integer_asm_op (4, TRUE)); \
969 fprintf (STREAM, ".Lskipconsts:\n"); \
971 /* store the static chain */ \
972 fprintf (STREAM, "\tl32r\ta8, .Lchainval\n"); \
973 fprintf (STREAM, "\ts32i\ta8, sp, %d\n", \
974 MIN_FRAME_SIZE - (5 * UNITS_PER_WORD)); \
976 /* set the proper stack pointer value */ \
977 fprintf (STREAM, "\tl32r\ta8, .Lfnaddr\n"); \
978 fprintf (STREAM, "\tl32i\ta9, a8, 0\n"); \
979 fprintf (STREAM, "\textui\ta9, a9, %d, 12\n", \
980 TARGET_BIG_ENDIAN ? 8 : 12); \
981 fprintf (STREAM, "\tslli\ta9, a9, 3\n"); \
982 fprintf (STREAM, "\taddi\ta9, a9, %d\n", -MIN_FRAME_SIZE); \
983 fprintf (STREAM, "\tsub\ta9, sp, a9\n"); \
984 fprintf (STREAM, "\tmovsp\tsp, a9\n"); \
986 /* jump to the instruction following the entry */ \
987 fprintf (STREAM, "\taddi\ta8, a8, 3\n"); \
988 fprintf (STREAM, "\tjx\ta8\n"); \
989 fprintf (STREAM, "\t.end no-generics\n"); \
992 /* Size in bytes of the trampoline, as an integer. */
993 #define TRAMPOLINE_SIZE 49
995 /* Alignment required for trampolines, in bits. */
996 #define TRAMPOLINE_ALIGNMENT (32)
998 /* A C statement to initialize the variable parts of a trampoline. */
999 #define INITIALIZE_TRAMPOLINE(ADDR, FUNC, CHAIN) \
1002 emit_move_insn (gen_rtx_MEM (SImode, plus_constant (addr, 8)), FUNC); \
1003 emit_move_insn (gen_rtx_MEM (SImode, plus_constant (addr, 12)), CHAIN); \
1004 emit_library_call (gen_rtx (SYMBOL_REF, Pmode, "__xtensa_sync_caches"), \
1005 0, VOIDmode, 1, addr, Pmode); \
1008 /* Define the `__builtin_va_list' type for the ABI. */
1009 #define BUILD_VA_LIST_TYPE(VALIST) \
1010 (VALIST) = xtensa_build_va_list ()
1012 /* If defined, is a C expression that produces the machine-specific
1013 code for a call to '__builtin_saveregs'. This code will be moved
1014 to the very beginning of the function, before any parameter access
1015 are made. The return value of this function should be an RTX that
1016 contains the value to use as the return of '__builtin_saveregs'. */
1017 #define EXPAND_BUILTIN_SAVEREGS \
1018 xtensa_builtin_saveregs
1020 /* Implement `va_start' for varargs and stdarg. */
1021 #define EXPAND_BUILTIN_VA_START(valist, nextarg) \
1022 xtensa_va_start (valist, nextarg)
1024 /* Implement `va_arg'. */
1025 #define EXPAND_BUILTIN_VA_ARG(valist, type) \
1026 xtensa_va_arg (valist, type)
1028 /* If defined, a C expression that produces the machine-specific code
1029 to setup the stack so that arbitrary frames can be accessed.
1031 On Xtensa, a stack back-trace must always begin from the stack pointer,
1032 so that the register overflow save area can be located. However, the
1033 stack-walking code in GCC always begins from the hard_frame_pointer
1034 register, not the stack pointer. The frame pointer is usually equal
1035 to the stack pointer, but the __builtin_return_address and
1036 __builtin_frame_address functions will not work if count > 0 and
1037 they are called from a routine that uses alloca. These functions
1038 are not guaranteed to work at all if count > 0 so maybe that is OK.
1040 A nicer solution would be to allow the architecture-specific files to
1041 specify whether to start from the stack pointer or frame pointer. That
1042 would also allow us to skip the machine->accesses_prev_frame stuff that
1043 we currently need to ensure that there is a frame pointer when these
1044 builtin functions are used. */
1046 #define SETUP_FRAME_ADDRESSES xtensa_setup_frame_addresses
1048 /* A C expression whose value is RTL representing the address in a
1049 stack frame where the pointer to the caller's frame is stored.
1050 Assume that FRAMEADDR is an RTL expression for the address of the
1053 For Xtensa, there is no easy way to get the frame pointer if it is
1054 not equivalent to the stack pointer. Moreover, the result of this
1055 macro is used for continuing to walk back up the stack, so it must
1056 return the stack pointer address. Thus, there is some inconsistency
1057 here in that __builtin_frame_address will return the frame pointer
1058 when count == 0 and the stack pointer when count > 0. */
1060 #define DYNAMIC_CHAIN_ADDRESS(frame) \
1061 gen_rtx (PLUS, Pmode, frame, \
1062 gen_rtx_CONST_INT (VOIDmode, -3 * UNITS_PER_WORD))
1064 /* Define this if the return address of a particular stack frame is
1065 accessed from the frame pointer of the previous stack frame. */
1066 #define RETURN_ADDR_IN_PREVIOUS_FRAME
1068 /* A C expression whose value is RTL representing the value of the
1069 return address for the frame COUNT steps up from the current
1070 frame, after the prologue. */
1071 #define RETURN_ADDR_RTX xtensa_return_addr
1073 /* Addressing modes, and classification of registers for them. */
1075 /* C expressions which are nonzero if register number NUM is suitable
1076 for use as a base or index register in operand addresses. It may
1077 be either a suitable hard register or a pseudo register that has
1078 been allocated such a hard register. The difference between an
1079 index register and a base register is that the index register may
1082 #define REGNO_OK_FOR_BASE_P(NUM) \
1083 (GP_REG_P (NUM) || GP_REG_P ((unsigned) reg_renumber[NUM]))
1085 #define REGNO_OK_FOR_INDEX_P(NUM) 0
1087 /* C expressions that are nonzero if X (assumed to be a `reg' RTX) is
1088 valid for use as a base or index register. For hard registers, it
1089 should always accept those which the hardware permits and reject
1090 the others. Whether the macro accepts or rejects pseudo registers
1091 must be controlled by `REG_OK_STRICT'. This usually requires two
1092 variant definitions, of which `REG_OK_STRICT' controls the one
1093 actually used. The difference between an index register and a base
1094 register is that the index register may be scaled. */
1096 #ifdef REG_OK_STRICT
1098 #define REG_OK_FOR_INDEX_P(X) 0
1099 #define REG_OK_FOR_BASE_P(X) \
1100 REGNO_OK_FOR_BASE_P (REGNO (X))
1102 #else /* !REG_OK_STRICT */
1104 #define REG_OK_FOR_INDEX_P(X) 0
1105 #define REG_OK_FOR_BASE_P(X) \
1106 ((REGNO (X) >= FIRST_PSEUDO_REGISTER) || (GP_REG_P (REGNO (X))))
1108 #endif /* !REG_OK_STRICT */
1110 /* Maximum number of registers that can appear in a valid memory address. */
1111 #define MAX_REGS_PER_ADDRESS 1
1113 /* Identify valid Xtensa addresses. */
1114 #define GO_IF_LEGITIMATE_ADDRESS(MODE, ADDR, LABEL) \
1116 rtx xinsn = (ADDR); \
1118 /* allow constant pool addresses */ \
1119 if ((MODE) != BLKmode && GET_MODE_SIZE (MODE) >= UNITS_PER_WORD \
1120 && constantpool_address_p (xinsn)) \
1123 while (GET_CODE (xinsn) == SUBREG) \
1124 xinsn = SUBREG_REG (xinsn); \
1126 /* allow base registers */ \
1127 if (GET_CODE (xinsn) == REG && REG_OK_FOR_BASE_P (xinsn)) \
1130 /* check for "register + offset" addressing */ \
1131 if (GET_CODE (xinsn) == PLUS) \
1133 rtx xplus0 = XEXP (xinsn, 0); \
1134 rtx xplus1 = XEXP (xinsn, 1); \
1135 enum rtx_code code0; \
1136 enum rtx_code code1; \
1138 while (GET_CODE (xplus0) == SUBREG) \
1139 xplus0 = SUBREG_REG (xplus0); \
1140 code0 = GET_CODE (xplus0); \
1142 while (GET_CODE (xplus1) == SUBREG) \
1143 xplus1 = SUBREG_REG (xplus1); \
1144 code1 = GET_CODE (xplus1); \
1146 /* swap operands if necessary so the register is first */ \
1147 if (code0 != REG && code1 == REG) \
1149 xplus0 = XEXP (xinsn, 1); \
1150 xplus1 = XEXP (xinsn, 0); \
1151 code0 = GET_CODE (xplus0); \
1152 code1 = GET_CODE (xplus1); \
1155 if (code0 == REG && REG_OK_FOR_BASE_P (xplus0) \
1156 && code1 == CONST_INT \
1157 && xtensa_mem_offset (INTVAL (xplus1), (MODE))) \
1164 /* A C expression that is 1 if the RTX X is a constant which is a
1165 valid address. This is defined to be the same as 'CONSTANT_P (X)',
1166 but rejecting CONST_DOUBLE. */
1167 #define CONSTANT_ADDRESS_P(X) \
1168 ((GET_CODE (X) == LABEL_REF || GET_CODE (X) == SYMBOL_REF \
1169 || GET_CODE (X) == CONST_INT || GET_CODE (X) == HIGH \
1170 || (GET_CODE (X) == CONST)))
1172 /* Nonzero if the constant value X is a legitimate general operand.
1173 It is given that X satisfies CONSTANT_P or is a CONST_DOUBLE. */
1174 #define LEGITIMATE_CONSTANT_P(X) 1
1176 /* A C expression that is nonzero if X is a legitimate immediate
1177 operand on the target machine when generating position independent
1179 #define LEGITIMATE_PIC_OPERAND_P(X) \
1180 ((GET_CODE (X) != SYMBOL_REF || SYMBOL_REF_FLAG (X)) \
1181 && GET_CODE (X) != LABEL_REF \
1182 && GET_CODE (X) != CONST)
1184 /* Tell GCC how to use ADDMI to generate addresses. */
1185 #define LEGITIMIZE_ADDRESS(X, OLDX, MODE, WIN) \
1188 if (GET_CODE (xinsn) == PLUS) \
1190 rtx plus0 = XEXP (xinsn, 0); \
1191 rtx plus1 = XEXP (xinsn, 1); \
1193 if (GET_CODE (plus0) != REG && GET_CODE (plus1) == REG) \
1195 plus0 = XEXP (xinsn, 1); \
1196 plus1 = XEXP (xinsn, 0); \
1199 if (GET_CODE (plus0) == REG \
1200 && GET_CODE (plus1) == CONST_INT \
1201 && !xtensa_mem_offset (INTVAL (plus1), MODE) \
1202 && !xtensa_simm8 (INTVAL (plus1)) \
1203 && xtensa_mem_offset (INTVAL (plus1) & 0xff, MODE) \
1204 && xtensa_simm8x256 (INTVAL (plus1) & ~0xff)) \
1206 rtx temp = gen_reg_rtx (Pmode); \
1207 emit_insn (gen_rtx (SET, Pmode, temp, \
1208 gen_rtx (PLUS, Pmode, plus0, \
1209 GEN_INT (INTVAL (plus1) & ~0xff)))); \
1210 (X) = gen_rtx (PLUS, Pmode, temp, \
1211 GEN_INT (INTVAL (plus1) & 0xff)); \
1218 /* Treat constant-pool references as "mode dependent" since they can
1219 only be accessed with SImode loads. This works around a bug in the
1220 combiner where a constant pool reference is temporarily converted
1221 to an HImode load, which is then assumed to zero-extend based on
1222 our definition of LOAD_EXTEND_OP. This is wrong because the high
1223 bits of a 16-bit value in the constant pool are now sign-extended
1226 #define GO_IF_MODE_DEPENDENT_ADDRESS(ADDR, LABEL) \
1228 if (constantpool_address_p (ADDR)) \
1232 /* Specify the machine mode that this machine uses
1233 for the index in the tablejump instruction. */
1234 #define CASE_VECTOR_MODE (SImode)
1236 /* Define this if the tablejump instruction expects the table
1237 to contain offsets from the address of the table.
1238 Do not define this if the table should contain absolute addresses. */
1239 /* #define CASE_VECTOR_PC_RELATIVE */
1241 /* Define this as 1 if 'char' should by default be signed; else as 0. */
1242 #define DEFAULT_SIGNED_CHAR 0
1244 /* Max number of bytes we can move from memory to memory
1245 in one reasonably fast instruction. */
1247 #define MAX_MOVE_MAX 4
1249 /* Prefer word-sized loads. */
1250 #define SLOW_BYTE_ACCESS 1
1252 /* Xtensa doesn't have any instructions that set integer values based on the
1253 results of comparisons, but the simplification code in the combiner also
1254 uses this macro. The value should be either 1 or -1 to enable some
1255 optimizations in the combiner; I'm not sure which is better for us.
1256 Since we've been using 1 for a while, it should probably stay that way for
1258 #define STORE_FLAG_VALUE 1
1260 /* Shift instructions ignore all but the low-order few bits. */
1261 #define SHIFT_COUNT_TRUNCATED 1
1263 /* Value is 1 if truncating an integer of INPREC bits to OUTPREC bits
1264 is done just by pretending it is already truncated. */
1265 #define TRULY_NOOP_TRUNCATION(OUTPREC, INPREC) 1
1267 /* Specify the machine mode that pointers have.
1268 After generation of rtl, the compiler makes no further distinction
1269 between pointers and any other objects of this machine mode. */
1270 #define Pmode SImode
1272 /* A function address in a call instruction is a word address (for
1273 indexing purposes) so give the MEM rtx a words's mode. */
1274 #define FUNCTION_MODE SImode
1276 /* A C expression for the cost of moving data from a register in
1277 class FROM to one in class TO. The classes are expressed using
1278 the enumeration values such as 'GENERAL_REGS'. A value of 2 is
1279 the default; other values are interpreted relative to that. */
1280 #define REGISTER_MOVE_COST(MODE, FROM, TO) \
1281 (((FROM) == (TO) && (FROM) != BR_REGS && (TO) != BR_REGS) \
1283 : (reg_class_subset_p ((FROM), AR_REGS) \
1284 && reg_class_subset_p ((TO), AR_REGS) \
1286 : (reg_class_subset_p ((FROM), AR_REGS) \
1287 && (TO) == ACC_REG \
1289 : ((FROM) == ACC_REG \
1290 && reg_class_subset_p ((TO), AR_REGS) \
1294 #define MEMORY_MOVE_COST(MODE, CLASS, IN) 4
1296 #define BRANCH_COST 3
1298 /* Optionally define this if you have added predicates to
1299 'MACHINE.c'. This macro is called within an initializer of an
1300 array of structures. The first field in the structure is the
1301 name of a predicate and the second field is an array of rtl
1302 codes. For each predicate, list all rtl codes that can be in
1303 expressions matched by the predicate. The list should have a
1306 #define PREDICATE_CODES \
1307 {"add_operand", { REG, CONST_INT, SUBREG }}, \
1308 {"arith_operand", { REG, CONST_INT, SUBREG }}, \
1309 {"nonimmed_operand", { REG, SUBREG, MEM }}, \
1310 {"mem_operand", { MEM }}, \
1311 {"mask_operand", { REG, CONST_INT, SUBREG }}, \
1312 {"extui_fldsz_operand", { CONST_INT }}, \
1313 {"sext_fldsz_operand", { CONST_INT }}, \
1314 {"lsbitnum_operand", { CONST_INT }}, \
1315 {"fpmem_offset_operand", { CONST_INT }}, \
1316 {"sext_operand", { REG, SUBREG, MEM }}, \
1317 {"branch_operand", { REG, CONST_INT, SUBREG }}, \
1318 {"ubranch_operand", { REG, CONST_INT, SUBREG }}, \
1319 {"call_insn_operand", { CONST_INT, CONST, SYMBOL_REF, REG }}, \
1320 {"move_operand", { REG, SUBREG, MEM, CONST_INT, CONST_DOUBLE, \
1321 CONST, SYMBOL_REF, LABEL_REF }}, \
1322 {"non_const_move_operand", { REG, SUBREG, MEM }}, \
1323 {"const_float_1_operand", { CONST_DOUBLE }}, \
1324 {"branch_operator", { EQ, NE, LT, GE }}, \
1325 {"ubranch_operator", { LTU, GEU }}, \
1326 {"boolean_operator", { EQ, NE }},
1328 /* Control the assembler format that we output. */
1330 /* How to refer to registers in assembler output.
1331 This sequence is indexed by compiler's hard-register-number (see above). */
1332 #define REGISTER_NAMES \
1334 "a0", "sp", "a2", "a3", "a4", "a5", "a6", "a7", \
1335 "a8", "a9", "a10", "a11", "a12", "a13", "a14", "a15", \
1336 "fp", "argp", "b0", \
1337 "f0", "f1", "f2", "f3", "f4", "f5", "f6", "f7", \
1338 "f8", "f9", "f10", "f11", "f12", "f13", "f14", "f15", \
1342 /* If defined, a C initializer for an array of structures containing a
1343 name and a register number. This macro defines additional names
1344 for hard registers, thus allowing the 'asm' option in declarations
1345 to refer to registers using alternate names. */
1346 #define ADDITIONAL_REGISTER_NAMES \
1348 { "a1", 1 + GP_REG_FIRST } \
1351 #define PRINT_OPERAND(FILE, X, CODE) print_operand (FILE, X, CODE)
1352 #define PRINT_OPERAND_ADDRESS(FILE, ADDR) print_operand_address (FILE, ADDR)
1354 /* Recognize machine-specific patterns that may appear within
1355 constants. Used for PIC-specific UNSPECs. */
1356 #define OUTPUT_ADDR_CONST_EXTRA(STREAM, X, FAIL) \
1358 if (flag_pic && GET_CODE (X) == UNSPEC && XVECLEN ((X), 0) == 1) \
1360 switch (XINT ((X), 1)) \
1363 output_addr_const ((STREAM), XVECEXP ((X), 0, 0)); \
1364 fputs ("@PLT", (STREAM)); \
1375 /* Globalizing directive for a label. */
1376 #define GLOBAL_ASM_OP "\t.global\t"
1378 /* This says how to define a global common symbol. */
1379 #define ASM_OUTPUT_COMMON(STREAM, NAME, SIZE, ROUNDED) \
1380 xtensa_declare_object (STREAM, NAME, "\n\t.comm\t", ",%u\n", (SIZE))
1382 /* This says how to define a local common symbol (ie, not visible to
1384 #define ASM_OUTPUT_LOCAL(STREAM, NAME, SIZE, ROUNDED) \
1385 xtensa_declare_object (STREAM, NAME, "\n\t.lcomm\t", ",%u\n", (SIZE))
1387 /* This is how to output an element of a case-vector that is absolute. */
1388 #define ASM_OUTPUT_ADDR_VEC_ELT(STREAM, VALUE) \
1389 fprintf (STREAM, "%s%sL%u\n", integer_asm_op (4, TRUE), \
1390 LOCAL_LABEL_PREFIX, VALUE)
1392 /* This is how to output an element of a case-vector that is relative.
1393 This is used for pc-relative code. */
1394 #define ASM_OUTPUT_ADDR_DIFF_ELT(STREAM, BODY, VALUE, REL) \
1396 fprintf (STREAM, "%s%sL%u-%sL%u\n", integer_asm_op (4, TRUE), \
1397 LOCAL_LABEL_PREFIX, (VALUE), \
1398 LOCAL_LABEL_PREFIX, (REL)); \
1401 /* This is how to output an assembler line that says to advance the
1402 location counter to a multiple of 2**LOG bytes. */
1403 #define ASM_OUTPUT_ALIGN(STREAM, LOG) \
1406 fprintf (STREAM, "\t.align\t%d\n", 1 << (LOG)); \
1409 /* Indicate that jump tables go in the text section. This is
1410 necessary when compiling PIC code. */
1411 #define JUMP_TABLES_IN_TEXT_SECTION (flag_pic)
1414 /* Define this macro for the rare case where the RTL needs some sort of
1415 machine-dependent fixup immediately before register allocation is done.
1417 If the stack frame size is too big to fit in the immediate field of
1418 the ENTRY instruction, we need to store the frame size in the
1419 constant pool. However, the code in xtensa_function_prologue runs too
1420 late to be able to add anything to the constant pool. Since the
1421 final frame size isn't known until reload is complete, this seems
1422 like the best place to do it.
1424 There may also be some fixup required if there is an incoming argument
1425 in a7 and the function requires a frame pointer. */
1427 #define MACHINE_DEPENDENT_REORG(INSN) xtensa_reorg (INSN)
1430 /* Define the strings to put out for each section in the object file. */
1431 #define TEXT_SECTION_ASM_OP "\t.text" /* instructions */
1432 #define DATA_SECTION_ASM_OP "\t.data" /* large data */
1435 /* Define output to appear before the constant pool. If the function
1436 has been assigned to a specific ELF section, or if it goes into a
1437 unique section, set the name of that section to be the literal
1439 #define ASM_OUTPUT_POOL_PROLOGUE(FILE, FUNNAME, FUNDECL, SIZE) \
1442 resolve_unique_section ((FUNDECL), 0, flag_function_sections); \
1443 fnsection = DECL_SECTION_NAME (FUNDECL); \
1444 if (fnsection != NULL_TREE) \
1446 const char *fnsectname = TREE_STRING_POINTER (fnsection); \
1447 fprintf (FILE, "\t.begin\tliteral_prefix %s\n", \
1448 strcmp (fnsectname, ".text") ? fnsectname : ""); \
1452 function_section (FUNDECL); \
1453 fprintf (FILE, "\t.literal_position\n"); \
1458 /* Define code to write out the ".end literal_prefix" directive for a
1459 function in a special section. This is appended to the standard ELF
1460 code for ASM_DECLARE_FUNCTION_SIZE. */
1461 #define XTENSA_DECLARE_FUNCTION_SIZE(FILE, FNAME, DECL) \
1462 if (DECL_SECTION_NAME (DECL) != NULL_TREE) \
1463 fprintf (FILE, "\t.end\tliteral_prefix\n")
1465 /* A C statement (with or without semicolon) to output a constant in
1466 the constant pool, if it needs special treatment. */
1467 #define ASM_OUTPUT_SPECIAL_POOL_ENTRY(FILE, X, MODE, ALIGN, LABELNO, JUMPTO) \
1469 xtensa_output_literal (FILE, X, MODE, LABELNO); \
1473 /* How to start an assembler comment. */
1474 #define ASM_COMMENT_START "#"
1476 /* Exception handling TODO!! */
1477 #define DWARF_UNWIND_INFO 0
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