xref: /openbsd/gnu/gcc/gcc/config/arc/arc.h (revision 404b540a)
1 /* Definitions of target machine for GNU compiler, Argonaut ARC cpu.
2    Copyright (C) 1994, 1995, 1997, 1998, 1999, 2000, 2001, 2002, 2004, 2005
3    Free Software Foundation, Inc.
4 
5 This file is part of GCC.
6 
7 GCC is free software; you can redistribute it and/or modify
8 it under the terms of the GNU General Public License as published by
9 the Free Software Foundation; either version 2, or (at your option)
10 any later version.
11 
12 GCC is distributed in the hope that it will be useful,
13 but WITHOUT ANY WARRANTY; without even the implied warranty of
14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
15 GNU General Public License for more details.
16 
17 You should have received a copy of the GNU General Public License
18 along with GCC; see the file COPYING.  If not, write to
19 the Free Software Foundation, 51 Franklin Street, Fifth Floor,
20 Boston, MA 02110-1301, USA.  */
21 
22 /* ??? This is an old port, and is undoubtedly suffering from bit rot.  */
23 
24 /* Things to do:
25 
26    - incscc, decscc?
27    - print active compiler options in assembler output
28 */
29 
30 
31 #undef ASM_SPEC
32 #undef LINK_SPEC
33 #undef STARTFILE_SPEC
34 #undef ENDFILE_SPEC
35 #undef SIZE_TYPE
36 #undef PTRDIFF_TYPE
37 #undef WCHAR_TYPE
38 #undef WCHAR_TYPE_SIZE
39 #undef ASM_OUTPUT_LABELREF
40 
41 /* Print subsidiary information on the compiler version in use.  */
42 #define TARGET_VERSION fprintf (stderr, " (arc)")
43 
44 /* Names to predefine in the preprocessor for this target machine.  */
45 #define TARGET_CPU_CPP_BUILTINS()		\
46   do						\
47     {						\
48 	builtin_define ("__arc__");		\
49 	if (TARGET_BIG_ENDIAN)			\
50 	  builtin_define ("__big_endian__");	\
51 	if (arc_cpu_type == 0)			\
52 	  builtin_define ("__base__");		\
53 	builtin_assert ("cpu=arc");		\
54 	builtin_assert ("machine=arc");		\
55     } while (0)
56 
57 /* Pass -mmangle-cpu if we get -mcpu=*.
58    Doing it this way lets one have it on as default with -mcpu=*,
59    but also lets one turn it off with -mno-mangle-cpu.  */
60 #define CC1_SPEC "\
61 %{mcpu=*:-mmangle-cpu} \
62 %{EB:%{EL:%emay not use both -EB and -EL}} \
63 %{EB:-mbig-endian} %{EL:-mlittle-endian} \
64 "
65 
66 #define ASM_SPEC "%{v} %{EB} %{EL}"
67 
68 #define LINK_SPEC "%{v} %{EB} %{EL}"
69 
70 #define STARTFILE_SPEC "%{!shared:crt0.o%s} crtinit.o%s"
71 
72 #define ENDFILE_SPEC "crtfini.o%s"
73 
74 /* Instruction set characteristics.
75    These are internal macros, set by the appropriate -mcpu= option.  */
76 
77 /* Nonzero means the cpu has a barrel shifter.  */
78 #define TARGET_SHIFTER 0
79 
80 /* Which cpu we're compiling for.  */
81 extern int arc_cpu_type;
82 
83 /* Check if CPU is an extension and set `arc_cpu_type' and `arc_mangle_cpu'
84    appropriately.  The result should be nonzero if the cpu is recognized,
85    otherwise zero.  This is intended to be redefined in a cover file.
86    This is used by arc_init.  */
87 #define ARC_EXTENSION_CPU(cpu) 0
88 
89 /* Sometimes certain combinations of command options do not make
90    sense on a particular target machine.  You can define a macro
91    `OVERRIDE_OPTIONS' to take account of this.  This macro, if
92    defined, is executed once just after all the command options have
93    been parsed.
94 
95    Don't use this macro to turn on various extra optimizations for
96    `-O'.  That is what `OPTIMIZATION_OPTIONS' is for.  */
97 
98 
99 #define OVERRIDE_OPTIONS \
100 do {				\
101   /* These need to be done at start up.  It's convenient to do them here.  */ \
102   arc_init ();			\
103 } while (0)
104 
105 /* Target machine storage layout.  */
106 
107 /* Define this if most significant bit is lowest numbered
108    in instructions that operate on numbered bit-fields.  */
109 #define BITS_BIG_ENDIAN 1
110 
111 /* Define this if most significant byte of a word is the lowest numbered.  */
112 #define BYTES_BIG_ENDIAN (TARGET_BIG_ENDIAN)
113 
114 /* Define this if most significant word of a multiword number is the lowest
115    numbered.  */
116 #define WORDS_BIG_ENDIAN (TARGET_BIG_ENDIAN)
117 
118 /* Define this to set the endianness to use in libgcc2.c, which can
119    not depend on target_flags.  */
120 #ifdef __big_endian__
121 #define LIBGCC2_WORDS_BIG_ENDIAN 1
122 #else
123 #define LIBGCC2_WORDS_BIG_ENDIAN 0
124 #endif
125 
126 /* Width of a word, in units (bytes).  */
127 #define UNITS_PER_WORD 4
128 
129 /* Define this macro if it is advisable to hold scalars in registers
130    in a wider mode than that declared by the program.  In such cases,
131    the value is constrained to be within the bounds of the declared
132    type, but kept valid in the wider mode.  The signedness of the
133    extension may differ from that of the type.  */
134 #define PROMOTE_MODE(MODE,UNSIGNEDP,TYPE) \
135 if (GET_MODE_CLASS (MODE) == MODE_INT		\
136     && GET_MODE_SIZE (MODE) < UNITS_PER_WORD)	\
137 {						\
138   (MODE) = SImode;				\
139 }
140 
141 /* Allocation boundary (in *bits*) for storing arguments in argument list.  */
142 #define PARM_BOUNDARY 32
143 
144 /* Boundary (in *bits*) on which stack pointer should be aligned.  */
145 #define STACK_BOUNDARY 64
146 
147 /* ALIGN FRAMES on word boundaries */
148 #define ARC_STACK_ALIGN(LOC) (((LOC)+7) & ~7)
149 
150 /* Allocation boundary (in *bits*) for the code of a function.  */
151 #define FUNCTION_BOUNDARY 32
152 
153 /* Alignment of field after `int : 0' in a structure.  */
154 #define EMPTY_FIELD_BOUNDARY 32
155 
156 /* Every structure's size must be a multiple of this.  */
157 #define STRUCTURE_SIZE_BOUNDARY 8
158 
159 /* A bit-field declared as `int' forces `int' alignment for the struct.  */
160 #define PCC_BITFIELD_TYPE_MATTERS 1
161 
162 /* No data type wants to be aligned rounder than this.  */
163 /* This is bigger than currently necessary for the ARC.  If 8 byte floats are
164    ever added it's not clear whether they'll need such alignment or not.  For
165    now we assume they will.  We can always relax it if necessary but the
166    reverse isn't true.  */
167 #define BIGGEST_ALIGNMENT 64
168 
169 /* The best alignment to use in cases where we have a choice.  */
170 #define FASTEST_ALIGNMENT 32
171 
172 /* Make strings word-aligned so strcpy from constants will be faster.  */
173 #define CONSTANT_ALIGNMENT(EXP, ALIGN)  \
174   ((TREE_CODE (EXP) == STRING_CST	\
175     && (ALIGN) < FASTEST_ALIGNMENT)	\
176    ? FASTEST_ALIGNMENT : (ALIGN))
177 
178 /* Make arrays of chars word-aligned for the same reasons.  */
179 #define DATA_ALIGNMENT(TYPE, ALIGN)		\
180   (TREE_CODE (TYPE) == ARRAY_TYPE		\
181    && TYPE_MODE (TREE_TYPE (TYPE)) == QImode	\
182    && (ALIGN) < FASTEST_ALIGNMENT ? FASTEST_ALIGNMENT : (ALIGN))
183 
184 /* Set this nonzero if move instructions will actually fail to work
185    when given unaligned data.  */
186 /* On the ARC the lower address bits are masked to 0 as necessary.  The chip
187    won't croak when given an unaligned address, but the insn will still fail
188    to produce the correct result.  */
189 #define STRICT_ALIGNMENT 1
190 
191 /* Layout of source language data types.  */
192 
193 #define SHORT_TYPE_SIZE		16
194 #define INT_TYPE_SIZE		32
195 #define LONG_TYPE_SIZE		32
196 #define LONG_LONG_TYPE_SIZE	64
197 #define FLOAT_TYPE_SIZE		32
198 #define DOUBLE_TYPE_SIZE	64
199 #define LONG_DOUBLE_TYPE_SIZE	64
200 
201 /* Define this as 1 if `char' should by default be signed; else as 0.  */
202 #define DEFAULT_SIGNED_CHAR 1
203 
204 #define SIZE_TYPE "long unsigned int"
205 #define PTRDIFF_TYPE "long int"
206 #define WCHAR_TYPE "short unsigned int"
207 #define WCHAR_TYPE_SIZE 16
208 
209 /* Standard register usage.  */
210 
211 /* Number of actual hardware registers.
212    The hardware registers are assigned numbers for the compiler
213    from 0 to just below FIRST_PSEUDO_REGISTER.
214    All registers that the compiler knows about must be given numbers,
215    even those that are not normally considered general registers.  */
216 /* Registers 61, 62, and 63 are not really registers and we needn't treat
217    them as such.  We still need a register for the condition code.  */
218 #define FIRST_PSEUDO_REGISTER 62
219 
220 /* 1 for registers that have pervasive standard uses
221    and are not available for the register allocator.
222 
223    0-28  - general purpose registers
224    29    - ilink1 (interrupt link register)
225    30    - ilink2 (interrupt link register)
226    31    - blink (branch link register)
227    32-59 - reserved for extensions
228    60    - LP_COUNT
229    61    - condition code
230 
231    For doc purposes:
232    61    - short immediate data indicator (setting flags)
233    62    - long immediate data indicator
234    63    - short immediate data indicator (not setting flags).
235 
236    The general purpose registers are further broken down into:
237    0-7   - arguments/results
238    8-15  - call used
239    16-23 - call saved
240    24    - call used, static chain pointer
241    25    - call used, gptmp
242    26    - global pointer
243    27    - frame pointer
244    28    - stack pointer
245 
246    By default, the extension registers are not available.  */
247 
248 #define FIXED_REGISTERS \
249 { 0, 0, 0, 0, 0, 0, 0, 0,	\
250   0, 0, 0, 0, 0, 0, 0, 0,	\
251   0, 0, 0, 0, 0, 0, 0, 0,	\
252   0, 0, 0, 1, 1, 1, 1, 0,	\
253 				\
254   1, 1, 1, 1, 1, 1, 1, 1,	\
255   1, 1, 1, 1, 1, 1, 1, 1,	\
256   1, 1, 1, 1, 1, 1, 1, 1,	\
257   1, 1, 1, 1, 1, 1 }
258 
259 /* 1 for registers not available across function calls.
260    These must include the FIXED_REGISTERS and also any
261    registers that can be used without being saved.
262    The latter must include the registers where values are returned
263    and the register where structure-value addresses are passed.
264    Aside from that, you can include as many other registers as you like.  */
265 
266 #define CALL_USED_REGISTERS \
267 { 1, 1, 1, 1, 1, 1, 1, 1,	\
268   1, 1, 1, 1, 1, 1, 1, 1,	\
269   0, 0, 0, 0, 0, 0, 0, 0,	\
270   1, 1, 1, 1, 1, 1, 1, 1,	\
271 				\
272   1, 1, 1, 1, 1, 1, 1, 1,	\
273   1, 1, 1, 1, 1, 1, 1, 1,	\
274   1, 1, 1, 1, 1, 1, 1, 1,	\
275   1, 1, 1, 1, 1, 1 }
276 
277 /* If defined, an initializer for a vector of integers, containing the
278    numbers of hard registers in the order in which GCC should
279    prefer to use them (from most preferred to least).  */
280 #define REG_ALLOC_ORDER \
281 { 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 0, 1,			\
282   16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 31,			\
283   32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47,	\
284   48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61,		\
285   27, 28, 29, 30 }
286 
287 /* Macro to conditionally modify fixed_regs/call_used_regs.  */
288 #define CONDITIONAL_REGISTER_USAGE			\
289 do {							\
290   if (PIC_OFFSET_TABLE_REGNUM != INVALID_REGNUM)	\
291     {							\
292       fixed_regs[PIC_OFFSET_TABLE_REGNUM] = 1;		\
293       call_used_regs[PIC_OFFSET_TABLE_REGNUM] = 1;	\
294     }							\
295 } while (0)
296 
297 /* Return number of consecutive hard regs needed starting at reg REGNO
298    to hold something of mode MODE.
299    This is ordinarily the length in words of a value of mode MODE
300    but can be less for certain modes in special long registers.  */
301 #define HARD_REGNO_NREGS(REGNO, MODE) \
302 ((GET_MODE_SIZE (MODE) + UNITS_PER_WORD - 1) / UNITS_PER_WORD)
303 
304 /* Value is 1 if hard register REGNO can hold a value of machine-mode MODE.  */
305 extern const unsigned int arc_hard_regno_mode_ok[];
306 extern unsigned int arc_mode_class[];
307 #define HARD_REGNO_MODE_OK(REGNO, MODE) \
308 ((arc_hard_regno_mode_ok[REGNO] & arc_mode_class[MODE]) != 0)
309 
310 /* A C expression that is nonzero if it is desirable to choose
311    register allocation so as to avoid move instructions between a
312    value of mode MODE1 and a value of mode MODE2.
313 
314    If `HARD_REGNO_MODE_OK (R, MODE1)' and `HARD_REGNO_MODE_OK (R,
315    MODE2)' are ever different for any R, then `MODES_TIEABLE_P (MODE1,
316    MODE2)' must be zero.  */
317 
318 /* Tie QI/HI/SI modes together.  */
319 #define MODES_TIEABLE_P(MODE1, MODE2) \
320 (GET_MODE_CLASS (MODE1) == MODE_INT		\
321  && GET_MODE_CLASS (MODE2) == MODE_INT		\
322  && GET_MODE_SIZE (MODE1) <= UNITS_PER_WORD	\
323  && GET_MODE_SIZE (MODE2) <= UNITS_PER_WORD)
324 
325 /* Register classes and constants.  */
326 
327 /* Define the classes of registers for register constraints in the
328    machine description.  Also define ranges of constants.
329 
330    One of the classes must always be named ALL_REGS and include all hard regs.
331    If there is more than one class, another class must be named NO_REGS
332    and contain no registers.
333 
334    The name GENERAL_REGS must be the name of a class (or an alias for
335    another name such as ALL_REGS).  This is the class of registers
336    that is allowed by "g" or "r" in a register constraint.
337    Also, registers outside this class are allocated only when
338    instructions express preferences for them.
339 
340    The classes must be numbered in nondecreasing order; that is,
341    a larger-numbered class must never be contained completely
342    in a smaller-numbered class.
343 
344    For any two classes, it is very desirable that there be another
345    class that represents their union.
346 
347    It is important that any condition codes have class NO_REGS.
348    See `register_operand'.  */
349 
350 enum reg_class {
351   NO_REGS, LPCOUNT_REG, GENERAL_REGS, ALL_REGS, LIM_REG_CLASSES
352 };
353 
354 #define N_REG_CLASSES (int) LIM_REG_CLASSES
355 
356 /* Give names of register classes as strings for dump file.  */
357 #define REG_CLASS_NAMES \
358 { "NO_REGS", "LPCOUNT_REG", "GENERAL_REGS", "ALL_REGS" }
359 
360 /* Define which registers fit in which classes.
361    This is an initializer for a vector of HARD_REG_SET
362    of length N_REG_CLASSES.  */
363 
364 #define REG_CLASS_CONTENTS \
365 { {0, 0}, {0, 0x10000000}, {0xffffffff, 0xfffffff}, \
366   {0xffffffff, 0x1fffffff} }
367 
368 /* The same information, inverted:
369    Return the class number of the smallest class containing
370    reg number REGNO.  This could be a conditional expression
371    or could index an array.  */
372 extern enum reg_class arc_regno_reg_class[FIRST_PSEUDO_REGISTER];
373 #define REGNO_REG_CLASS(REGNO) \
374 (arc_regno_reg_class[REGNO])
375 
376 /* The class value for index registers, and the one for base regs.  */
377 #define INDEX_REG_CLASS GENERAL_REGS
378 #define BASE_REG_CLASS GENERAL_REGS
379 
380 /* Get reg_class from a letter such as appears in the machine description.  */
381 #define REG_CLASS_FROM_LETTER(C) \
382 ((C) == 'l' ? LPCOUNT_REG /* ??? needed? */ \
383  : NO_REGS)
384 
385 /* These assume that REGNO is a hard or pseudo reg number.
386    They give nonzero only if REGNO is a hard reg of the suitable class
387    or a pseudo reg currently allocated to a suitable hard reg.
388    Since they use reg_renumber, they are safe only once reg_renumber
389    has been allocated, which happens in local-alloc.c.  */
390 #define REGNO_OK_FOR_BASE_P(REGNO) \
391 ((REGNO) < 32 || (unsigned) reg_renumber[REGNO] < 32)
392 #define REGNO_OK_FOR_INDEX_P(REGNO) \
393 ((REGNO) < 32 || (unsigned) reg_renumber[REGNO] < 32)
394 
395 /* Given an rtx X being reloaded into a reg required to be
396    in class CLASS, return the class of reg to actually use.
397    In general this is just CLASS; but on some machines
398    in some cases it is preferable to use a more restrictive class.  */
399 #define PREFERRED_RELOAD_CLASS(X,CLASS) \
400 (CLASS)
401 
402 /* Return the maximum number of consecutive registers
403    needed to represent mode MODE in a register of class CLASS.  */
404 #define CLASS_MAX_NREGS(CLASS, MODE) \
405 ((GET_MODE_SIZE (MODE) + UNITS_PER_WORD - 1) / UNITS_PER_WORD)
406 
407 /* The letters I, J, K, L, M, N, O, P in a register constraint string
408    can be used to stand for particular ranges of immediate operands.
409    This macro defines what the ranges are.
410    C is the letter, and VALUE is a constant value.
411    Return 1 if VALUE is in the range specified by C.  */
412 /* 'I' is used for short immediates (always signed).
413    'J' is used for long immediates.
414    'K' is used for any constant up to 64 bits (for 64x32 situations?).  */
415 
416 /* local to this file */
417 #define SMALL_INT(X) ((unsigned) ((X) + 0x100) < 0x200)
418 /* local to this file */
419 #define LARGE_INT(X) \
420 ((X) >= (-(HOST_WIDE_INT) 0x7fffffff - 1) \
421  && (unsigned HOST_WIDE_INT)(X) <= (unsigned HOST_WIDE_INT) 0xffffffff)
422 
423 #define CONST_OK_FOR_LETTER_P(VALUE, C) \
424 ((C) == 'I' ? SMALL_INT (VALUE)		\
425  : (C) == 'J' ? LARGE_INT (VALUE)	\
426  : (C) == 'K' ? 1			\
427  : 0)
428 
429 /* Similar, but for floating constants, and defining letters G and H.
430    Here VALUE is the CONST_DOUBLE rtx itself.  */
431 /* 'G' is used for integer values for the multiplication insns where the
432    operands are extended from 4 bytes to 8 bytes.
433    'H' is used when any 64 bit constant is allowed.  */
434 #define CONST_DOUBLE_OK_FOR_LETTER_P(VALUE, C) \
435 ((C) == 'G' ? arc_double_limm_p (VALUE) \
436  : (C) == 'H' ? 1 \
437  : 0)
438 
439 /* A C expression that defines the optional machine-dependent constraint
440    letters that can be used to segregate specific types of operands,
441    usually memory references, for the target machine.  It should return 1 if
442    VALUE corresponds to the operand type represented by the constraint letter
443    C.  If C is not defined as an extra constraint, the value returned should
444    be 0 regardless of VALUE.  */
445 /* ??? This currently isn't used.  Waiting for PIC.  */
446 #if 0
447 #define EXTRA_CONSTRAINT(VALUE, C) \
448 ((C) == 'R' ? (SYMBOL_REF_FUNCTION_P (VALUE) || GET_CODE (VALUE) == LABEL_REF) \
449  : 0)
450 #endif
451 
452 /* Stack layout and stack pointer usage.  */
453 
454 /* Define this macro if pushing a word onto the stack moves the stack
455    pointer to a smaller address.  */
456 #define STACK_GROWS_DOWNWARD
457 
458 /* Define this to nonzero if the nominal address of the stack frame
459    is at the high-address end of the local variables;
460    that is, each additional local variable allocated
461    goes at a more negative offset in the frame.  */
462 #define FRAME_GROWS_DOWNWARD 1
463 
464 /* Offset within stack frame to start allocating local variables at.
465    If FRAME_GROWS_DOWNWARD, this is the offset to the END of the
466    first local allocated.  Otherwise, it is the offset to the BEGINNING
467    of the first local allocated.  */
468 #define STARTING_FRAME_OFFSET 0
469 
470 /* Offset from the stack pointer register to the first location at which
471    outgoing arguments are placed.  */
472 #define STACK_POINTER_OFFSET FIRST_PARM_OFFSET (0)
473 
474 /* Offset of first parameter from the argument pointer register value.  */
475 /* 4 bytes for each of previous fp, return address, and previous gp.
476    4 byte reserved area for future considerations.  */
477 #define FIRST_PARM_OFFSET(FNDECL) 16
478 
479 /* A C expression whose value is RTL representing the address in a
480    stack frame where the pointer to the caller's frame is stored.
481    Assume that FRAMEADDR is an RTL expression for the address of the
482    stack frame itself.
483 
484    If you don't define this macro, the default is to return the value
485    of FRAMEADDR--that is, the stack frame address is also the address
486    of the stack word that points to the previous frame.  */
487 /* ??? unfinished */
488 /*define DYNAMIC_CHAIN_ADDRESS (FRAMEADDR)*/
489 
490 /* A C expression whose value is RTL representing the value of the
491    return address for the frame COUNT steps up from the current frame.
492    FRAMEADDR is the frame pointer of the COUNT frame, or the frame
493    pointer of the COUNT - 1 frame if `RETURN_ADDR_IN_PREVIOUS_FRAME'
494    is defined.  */
495 /* The current return address is in r31.  The return address of anything
496    farther back is at [%fp,4].  */
497 #if 0 /* The default value should work.  */
498 #define RETURN_ADDR_RTX(COUNT, FRAME) \
499 (((COUNT) == -1)							\
500  ? gen_rtx_REG (Pmode, 31)						\
501  : copy_to_reg (gen_rtx_MEM (Pmode,					\
502 			     memory_address (Pmode,			\
503 					     plus_constant ((FRAME),	\
504 							    UNITS_PER_WORD)))))
505 #endif
506 
507 /* Register to use for pushing function arguments.  */
508 #define STACK_POINTER_REGNUM 28
509 
510 /* Base register for access to local variables of the function.  */
511 #define FRAME_POINTER_REGNUM 27
512 
513 /* Base register for access to arguments of the function.  */
514 #define ARG_POINTER_REGNUM FRAME_POINTER_REGNUM
515 
516 /* Register in which static-chain is passed to a function.  This must
517    not be a register used by the prologue.  */
518 #define STATIC_CHAIN_REGNUM 24
519 
520 /* A C expression which is nonzero if a function must have and use a
521    frame pointer.  This expression is evaluated in the reload pass.
522    If its value is nonzero the function will have a frame pointer.  */
523 #define FRAME_POINTER_REQUIRED \
524 (current_function_calls_alloca)
525 
526 /* C statement to store the difference between the frame pointer
527    and the stack pointer values immediately after the function prologue.  */
528 #define INITIAL_FRAME_POINTER_OFFSET(VAR) \
529 ((VAR) = arc_compute_frame_size (get_frame_size ()))
530 
531 /* Function argument passing.  */
532 
533 /* If defined, the maximum amount of space required for outgoing
534    arguments will be computed and placed into the variable
535    `current_function_outgoing_args_size'.  No space will be pushed
536    onto the stack for each call; instead, the function prologue should
537    increase the stack frame size by this amount.  */
538 #define ACCUMULATE_OUTGOING_ARGS 1
539 
540 /* Value is the number of bytes of arguments automatically
541    popped when returning from a subroutine call.
542    FUNDECL is the declaration node of the function (as a tree),
543    FUNTYPE is the data type of the function (as a tree),
544    or for a library call it is an identifier node for the subroutine name.
545    SIZE is the number of bytes of arguments passed on the stack.  */
546 #define RETURN_POPS_ARGS(DECL, FUNTYPE, SIZE) 0
547 
548 /* Define a data type for recording info about an argument list
549    during the scan of that argument list.  This data type should
550    hold all necessary information about the function itself
551    and about the args processed so far, enough to enable macros
552    such as FUNCTION_ARG to determine where the next arg should go.  */
553 #define CUMULATIVE_ARGS int
554 
555 /* Initialize a variable CUM of type CUMULATIVE_ARGS
556    for a call to a function whose data type is FNTYPE.
557    For a library call, FNTYPE is 0.  */
558 #define INIT_CUMULATIVE_ARGS(CUM, FNTYPE, LIBNAME, INDIRECT, N_NAMED_ARGS) \
559 ((CUM) = 0)
560 
561 /* The number of registers used for parameter passing.  Local to this file.  */
562 #define MAX_ARC_PARM_REGS 8
563 
564 /* 1 if N is a possible register number for function argument passing.  */
565 #define FUNCTION_ARG_REGNO_P(N) \
566 ((unsigned) (N) < MAX_ARC_PARM_REGS)
567 
568 /* The ROUND_ADVANCE* macros are local to this file.  */
569 /* Round SIZE up to a word boundary.  */
570 #define ROUND_ADVANCE(SIZE) \
571 (((SIZE) + UNITS_PER_WORD - 1) / UNITS_PER_WORD)
572 
573 /* Round arg MODE/TYPE up to the next word boundary.  */
574 #define ROUND_ADVANCE_ARG(MODE, TYPE) \
575 ((MODE) == BLKmode				\
576  ? ROUND_ADVANCE (int_size_in_bytes (TYPE))	\
577  : ROUND_ADVANCE (GET_MODE_SIZE (MODE)))
578 
579 /* Round CUM up to the necessary point for argument MODE/TYPE.  */
580 #define ROUND_ADVANCE_CUM(CUM, MODE, TYPE) \
581 ((((MODE) == BLKmode ? TYPE_ALIGN (TYPE) : GET_MODE_BITSIZE (MODE)) \
582   > BITS_PER_WORD)	\
583  ? (((CUM) + 1) & ~1)	\
584  : (CUM))
585 
586 /* Return boolean indicating arg of type TYPE and mode MODE will be passed in
587    a reg.  This includes arguments that have to be passed by reference as the
588    pointer to them is passed in a reg if one is available (and that is what
589    we're given).
590    This macro is only used in this file.  */
591 #define PASS_IN_REG_P(CUM, MODE, TYPE) \
592 ((CUM) < MAX_ARC_PARM_REGS						\
593  && ((ROUND_ADVANCE_CUM ((CUM), (MODE), (TYPE))				\
594       + ROUND_ADVANCE_ARG ((MODE), (TYPE))				\
595       <= MAX_ARC_PARM_REGS)))
596 
597 /* Determine where to put an argument to a function.
598    Value is zero to push the argument on the stack,
599    or a hard register in which to store the argument.
600 
601    MODE is the argument's machine mode.
602    TYPE is the data type of the argument (as a tree).
603     This is null for libcalls where that information may
604     not be available.
605    CUM is a variable of type CUMULATIVE_ARGS which gives info about
606     the preceding args and about the function being called.
607    NAMED is nonzero if this argument is a named parameter
608     (otherwise it is an extra parameter matching an ellipsis).  */
609 /* On the ARC the first MAX_ARC_PARM_REGS args are normally in registers
610    and the rest are pushed.  */
611 #define FUNCTION_ARG(CUM, MODE, TYPE, NAMED) \
612 (PASS_IN_REG_P ((CUM), (MODE), (TYPE))					\
613  ? gen_rtx_REG ((MODE), ROUND_ADVANCE_CUM ((CUM), (MODE), (TYPE)))	\
614  : 0)
615 
616 /* Update the data in CUM to advance over an argument
617    of mode MODE and data type TYPE.
618    (TYPE is null for libcalls where that information may not be available.)  */
619 #define FUNCTION_ARG_ADVANCE(CUM, MODE, TYPE, NAMED) \
620 ((CUM) = (ROUND_ADVANCE_CUM ((CUM), (MODE), (TYPE)) \
621 	  + ROUND_ADVANCE_ARG ((MODE), (TYPE))))
622 
623 /* If defined, a C expression that gives the alignment boundary, in bits,
624    of an argument with the specified mode and type.  If it is not defined,
625    PARM_BOUNDARY is used for all arguments.  */
626 #define FUNCTION_ARG_BOUNDARY(MODE, TYPE) \
627 (((TYPE) ? TYPE_ALIGN (TYPE) : GET_MODE_BITSIZE (MODE)) <= PARM_BOUNDARY \
628  ? PARM_BOUNDARY \
629  : 2 * PARM_BOUNDARY)
630 
631 /* Function results.  */
632 
633 /* Define how to find the value returned by a function.
634    VALTYPE is the data type of the value (as a tree).
635    If the precise function being called is known, FUNC is its FUNCTION_DECL;
636    otherwise, FUNC is 0.  */
637 #define FUNCTION_VALUE(VALTYPE, FUNC) gen_rtx_REG (TYPE_MODE (VALTYPE), 0)
638 
639 /* Define how to find the value returned by a library function
640    assuming the value has mode MODE.  */
641 #define LIBCALL_VALUE(MODE) gen_rtx_REG (MODE, 0)
642 
643 /* 1 if N is a possible register number for a function value
644    as seen by the caller.  */
645 /* ??? What about r1 in DI/DF values.  */
646 #define FUNCTION_VALUE_REGNO_P(N) ((N) == 0)
647 
648 /* Tell GCC to use TARGET_RETURN_IN_MEMORY.  */
649 #define DEFAULT_PCC_STRUCT_RETURN 0
650 
651 /* EXIT_IGNORE_STACK should be nonzero if, when returning from a function,
652    the stack pointer does not matter.  The value is tested only in
653    functions that have frame pointers.
654    No definition is equivalent to always zero.  */
655 #define EXIT_IGNORE_STACK 0
656 
657 /* Epilogue delay slots.  */
658 #define DELAY_SLOTS_FOR_EPILOGUE arc_delay_slots_for_epilogue ()
659 
660 #define ELIGIBLE_FOR_EPILOGUE_DELAY(TRIAL, SLOTS_FILLED) \
661 arc_eligible_for_epilogue_delay (TRIAL, SLOTS_FILLED)
662 
663 /* Output assembler code to FILE to increment profiler label # LABELNO
664    for profiling a function entry.  */
665 #define FUNCTION_PROFILER(FILE, LABELNO)
666 
667 /* Trampolines.  */
668 /* ??? This doesn't work yet because GCC will use as the address of a nested
669    function the address of the trampoline.  We need to use that address
670    right shifted by 2.  It looks like we'll need PSImode after all. :-(  */
671 
672 /* Output assembler code for a block containing the constant parts
673    of a trampoline, leaving space for the variable parts.  */
674 /* On the ARC, the trampoline is quite simple as we have 32 bit immediate
675    constants.
676 
677 	mov r24,STATIC
678 	j.nd FUNCTION
679 */
680 #define TRAMPOLINE_TEMPLATE(FILE) \
681 do { \
682   assemble_aligned_integer (UNITS_PER_WORD, GEN_INT (0x631f7c00)); \
683   assemble_aligned_integer (UNITS_PER_WORD, const0_rtx); \
684   assemble_aligned_integer (UNITS_PER_WORD, GEN_INT (0x381f0000)); \
685   assemble_aligned_integer (UNITS_PER_WORD, const0_rtx); \
686 } while (0)
687 
688 /* Length in units of the trampoline for entering a nested function.  */
689 #define TRAMPOLINE_SIZE 16
690 
691 /* Emit RTL insns to initialize the variable parts of a trampoline.
692    FNADDR is an RTX for the address of the function's pure code.
693    CXT is an RTX for the static chain value for the function.  */
694 #define INITIALIZE_TRAMPOLINE(TRAMP, FNADDR, CXT) \
695 do { \
696   emit_move_insn (gen_rtx_MEM (SImode, plus_constant (TRAMP, 4)), CXT); \
697   emit_move_insn (gen_rtx_MEM (SImode, plus_constant (TRAMP, 12)), FNADDR); \
698   emit_insn (gen_flush_icache (validize_mem (gen_rtx_MEM (SImode, TRAMP)))); \
699 } while (0)
700 
701 /* Addressing modes, and classification of registers for them.  */
702 
703 /* Maximum number of registers that can appear in a valid memory address.  */
704 /* The `ld' insn allows 2, but the `st' insn only allows 1.  */
705 #define MAX_REGS_PER_ADDRESS 1
706 
707 /* We have pre inc/dec (load/store with update).  */
708 #define HAVE_PRE_INCREMENT 1
709 #define HAVE_PRE_DECREMENT 1
710 
711 /* Recognize any constant value that is a valid address.  */
712 #define CONSTANT_ADDRESS_P(X) \
713 (GET_CODE (X) == LABEL_REF || GET_CODE (X) == SYMBOL_REF	\
714  || GET_CODE (X) == CONST_INT || GET_CODE (X) == CONST)
715 
716 /* Nonzero if the constant value X is a legitimate general operand.
717    We can handle any 32 or 64 bit constant.  */
718 /* "1" should work since the largest constant should be a 64 bit critter.  */
719 /* ??? Not sure what to do for 64x32 compiler.  */
720 #define LEGITIMATE_CONSTANT_P(X) 1
721 
722 /* The macros REG_OK_FOR..._P assume that the arg is a REG rtx
723    and check its validity for a certain class.
724    We have two alternate definitions for each of them.
725    The usual definition accepts all pseudo regs; the other rejects
726    them unless they have been allocated suitable hard regs.
727    The symbol REG_OK_STRICT causes the latter definition to be used.
728 
729    Most source files want to accept pseudo regs in the hope that
730    they will get allocated to the class that the insn wants them to be in.
731    Source files for reload pass need to be strict.
732    After reload, it makes no difference, since pseudo regs have
733    been eliminated by then.  */
734 
735 #ifndef REG_OK_STRICT
736 
737 /* Nonzero if X is a hard reg that can be used as an index
738    or if it is a pseudo reg.  */
739 #define REG_OK_FOR_INDEX_P(X) \
740 ((unsigned) REGNO (X) - 32 >= FIRST_PSEUDO_REGISTER - 32)
741 /* Nonzero if X is a hard reg that can be used as a base reg
742    or if it is a pseudo reg.  */
743 #define REG_OK_FOR_BASE_P(X) \
744 ((unsigned) REGNO (X) - 32 >= FIRST_PSEUDO_REGISTER - 32)
745 
746 #else
747 
748 /* Nonzero if X is a hard reg that can be used as an index.  */
749 #define REG_OK_FOR_INDEX_P(X) REGNO_OK_FOR_INDEX_P (REGNO (X))
750 /* Nonzero if X is a hard reg that can be used as a base reg.  */
751 #define REG_OK_FOR_BASE_P(X) REGNO_OK_FOR_BASE_P (REGNO (X))
752 
753 #endif
754 
755 /* GO_IF_LEGITIMATE_ADDRESS recognizes an RTL expression
756    that is a valid memory address for an instruction.
757    The MODE argument is the machine mode for the MEM expression
758    that wants to use this address.  */
759 /* The `ld' insn allows [reg],[reg+shimm],[reg+limm],[reg+reg],[limm]
760    but the `st' insn only allows [reg],[reg+shimm],[limm].
761    The only thing we can do is only allow the most strict case `st' and hope
762    other parts optimize out the restrictions for `ld'.  */
763 
764 /* local to this file */
765 #define RTX_OK_FOR_BASE_P(X) \
766 (REG_P (X) && REG_OK_FOR_BASE_P (X))
767 
768 /* local to this file */
769 #define RTX_OK_FOR_INDEX_P(X) \
770 (0 && /*???*/ REG_P (X) && REG_OK_FOR_INDEX_P (X))
771 
772 /* local to this file */
773 /* ??? Loads can handle any constant, stores can only handle small ones.  */
774 #define RTX_OK_FOR_OFFSET_P(X) \
775 (GET_CODE (X) == CONST_INT && SMALL_INT (INTVAL (X)))
776 
777 #define LEGITIMATE_OFFSET_ADDRESS_P(MODE, X) \
778 (GET_CODE (X) == PLUS				\
779  && RTX_OK_FOR_BASE_P (XEXP (X, 0))		\
780  && (RTX_OK_FOR_INDEX_P (XEXP (X, 1))		\
781      || RTX_OK_FOR_OFFSET_P (XEXP (X, 1))))
782 
783 #define GO_IF_LEGITIMATE_ADDRESS(MODE, X, ADDR)		\
784 { if (RTX_OK_FOR_BASE_P (X))				\
785     goto ADDR;						\
786   if (LEGITIMATE_OFFSET_ADDRESS_P ((MODE), (X)))	\
787     goto ADDR;						\
788   if (GET_CODE (X) == CONST_INT && LARGE_INT (INTVAL (X))) \
789     goto ADDR;						\
790   if (GET_CODE (X) == SYMBOL_REF			\
791 	   || GET_CODE (X) == LABEL_REF			\
792 	   || GET_CODE (X) == CONST)			\
793     goto ADDR;						\
794   if ((GET_CODE (X) == PRE_DEC || GET_CODE (X) == PRE_INC) \
795       /* We're restricted here by the `st' insn.  */	\
796       && RTX_OK_FOR_BASE_P (XEXP ((X), 0)))		\
797     goto ADDR;						\
798 }
799 
800 /* Go to LABEL if ADDR (a legitimate address expression)
801    has an effect that depends on the machine mode it is used for.  */
802 #define GO_IF_MODE_DEPENDENT_ADDRESS(ADDR, LABEL) \
803 { if (GET_CODE (ADDR) == PRE_DEC)	\
804     goto LABEL;				\
805   if (GET_CODE (ADDR) == PRE_INC)	\
806     goto LABEL;				\
807 }
808 
809 /* Given a comparison code (EQ, NE, etc.) and the first operand of a COMPARE,
810    return the mode to be used for the comparison.  */
811 #define SELECT_CC_MODE(OP, X, Y) \
812 arc_select_cc_mode (OP, X, Y)
813 
814 /* Return nonzero if SELECT_CC_MODE will never return MODE for a
815    floating point inequality comparison.  */
816 #define REVERSIBLE_CC_MODE(MODE) 1 /*???*/
817 
818 /* Costs.  */
819 
820 /* Compute extra cost of moving data between one register class
821    and another.  */
822 #define REGISTER_MOVE_COST(MODE, CLASS1, CLASS2) 2
823 
824 /* Compute the cost of moving data between registers and memory.  */
825 /* Memory is 3 times as expensive as registers.
826    ??? Is that the right way to look at it?  */
827 #define MEMORY_MOVE_COST(MODE,CLASS,IN) \
828 (GET_MODE_SIZE (MODE) <= UNITS_PER_WORD ? 6 : 12)
829 
830 /* The cost of a branch insn.  */
831 /* ??? What's the right value here?  Branches are certainly more
832    expensive than reg->reg moves.  */
833 #define BRANCH_COST 2
834 
835 /* Nonzero if access to memory by bytes is slow and undesirable.
836    For RISC chips, it means that access to memory by bytes is no
837    better than access by words when possible, so grab a whole word
838    and maybe make use of that.  */
839 #define SLOW_BYTE_ACCESS 1
840 
841 /* Define this macro if it is as good or better to call a constant
842    function address than to call an address kept in a register.  */
843 /* On the ARC, calling through registers is slow.  */
844 #define NO_FUNCTION_CSE
845 
846 /* Section selection.  */
847 /* WARNING: These section names also appear in dwarfout.c.  */
848 
849 /* The names of the text, data, and readonly-data sections are runtime
850    selectable.  */
851 
852 #define ARC_SECTION_FORMAT		"\t.section %s"
853 #define ARC_DEFAULT_TEXT_SECTION	".text"
854 #define ARC_DEFAULT_DATA_SECTION	".data"
855 #define ARC_DEFAULT_RODATA_SECTION	".rodata"
856 
857 extern const char *arc_text_section, *arc_data_section, *arc_rodata_section;
858 
859 /* initfini.c uses this in an asm.  */
860 #if defined (CRT_INIT) || defined (CRT_FINI)
861 #define TEXT_SECTION_ASM_OP	"\t.section .text"
862 #else
863 #define TEXT_SECTION_ASM_OP	arc_text_section
864 #endif
865 #define DATA_SECTION_ASM_OP	arc_data_section
866 
867 #undef  READONLY_DATA_SECTION_ASM_OP
868 #define READONLY_DATA_SECTION_ASM_OP	arc_rodata_section
869 
870 #define BSS_SECTION_ASM_OP	"\t.section .bss"
871 
872 /* Define this macro if jump tables (for tablejump insns) should be
873    output in the text section, along with the assembler instructions.
874    Otherwise, the readonly data section is used.
875    This macro is irrelevant if there is no separate readonly data section.  */
876 /*#define JUMP_TABLES_IN_TEXT_SECTION*/
877 
878 /* For DWARF.  Marginally different than default so output is "prettier"
879    (and consistent with above).  */
880 #define PUSHSECTION_ASM_OP "\t.section "
881 
882 /* Tell crtstuff.c we're using ELF.  */
883 #define OBJECT_FORMAT_ELF
884 
885 /* PIC */
886 
887 /* The register number of the register used to address a table of static
888    data addresses in memory.  In some cases this register is defined by a
889    processor's ``application binary interface'' (ABI).  When this macro
890    is defined, RTL is generated for this register once, as with the stack
891    pointer and frame pointer registers.  If this macro is not defined, it
892    is up to the machine-dependent files to allocate such a register (if
893    necessary).  */
894 #define PIC_OFFSET_TABLE_REGNUM  (flag_pic ? 26 : INVALID_REGNUM)
895 
896 /* Define this macro if the register defined by PIC_OFFSET_TABLE_REGNUM is
897    clobbered by calls.  Do not define this macro if PIC_OFFSET_TABLE_REGNUM
898    is not defined.  */
899 /* This register is call-saved on the ARC.  */
900 /*#define PIC_OFFSET_TABLE_REG_CALL_CLOBBERED*/
901 
902 /* A C expression that is nonzero if X is a legitimate immediate
903    operand on the target machine when generating position independent code.
904    You can assume that X satisfies CONSTANT_P, so you need not
905    check this.  You can also assume `flag_pic' is true, so you need not
906    check it either.  You need not define this macro if all constants
907    (including SYMBOL_REF) can be immediate operands when generating
908    position independent code.  */
909 /*#define LEGITIMATE_PIC_OPERAND_P(X)*/
910 
911 /* Control the assembler format that we output.  */
912 
913 /* A C string constant describing how to begin a comment in the target
914    assembler language.  The compiler assumes that the comment will
915    end at the end of the line.  */
916 #define ASM_COMMENT_START ";"
917 
918 /* Output to assembler file text saying following lines
919    may contain character constants, extra white space, comments, etc.  */
920 #define ASM_APP_ON ""
921 
922 /* Output to assembler file text saying following lines
923    no longer contain unusual constructs.  */
924 #define ASM_APP_OFF ""
925 
926 /* Globalizing directive for a label.  */
927 #define GLOBAL_ASM_OP "\t.global\t"
928 
929 /* This is how to output a reference to a user-level label named NAME.
930    `assemble_name' uses this.  */
931 /* We mangle all user labels to provide protection from linking code
932    compiled for different cpus.  */
933 /* We work around a dwarfout.c deficiency by watching for labels from it and
934    not adding the '_' prefix nor the cpu suffix.  There is a comment in
935    dwarfout.c that says it should be using (*targetm.asm_out.internal_label).  */
936 extern const char *arc_mangle_cpu;
937 #define ASM_OUTPUT_LABELREF(FILE, NAME) \
938 do {							\
939   if ((NAME)[0] == '.' && (NAME)[1] == 'L')		\
940     fprintf (FILE, "%s", NAME);				\
941   else							\
942     {							\
943       fputc ('_', FILE);				\
944       if (TARGET_MANGLE_CPU && arc_mangle_cpu != NULL)	\
945 	fprintf (FILE, "%s_", arc_mangle_cpu);		\
946       fprintf (FILE, "%s", NAME);			\
947     }							\
948 } while (0)
949 
950 /* Assembler pseudo-op to equate one value with another.  */
951 /* ??? This is needed because dwarfout.c provides a default definition too
952    late for defaults.h (which contains the default definition of ASM_OUTPUT_DEF
953    that we use).  */
954 #define SET_ASM_OP "\t.set\t"
955 
956 /* How to refer to registers in assembler output.
957    This sequence is indexed by compiler's hard-register-number (see above).  */
958 #define REGISTER_NAMES \
959 {"r0", "r1", "r2", "r3", "r4", "r5", "r6", "r7",		\
960  "r8", "r9", "r10", "r11", "r12", "r13", "r14", "r15",		\
961  "r16", "r17", "r18", "r19", "r20", "r21", "r22", "r23",	\
962  "r24", "r25", "r26", "fp", "sp", "ilink1", "ilink2", "blink",	\
963  "r32", "r33", "r34", "r35", "r36", "r37", "r38", "r39",	\
964  "r40", "r41", "r42", "r43", "r44", "r45", "r46", "r47",	\
965  "r48", "r49", "r50", "r51", "r52", "r53", "r54", "r55",	\
966  "r56", "r57", "r58", "r59", "lp_count", "cc"}
967 
968 /* Entry to the insn conditionalizer.  */
969 #define FINAL_PRESCAN_INSN(INSN, OPVEC, NOPERANDS) \
970 arc_final_prescan_insn (INSN, OPVEC, NOPERANDS)
971 
972 /* A C expression which evaluates to true if CODE is a valid
973    punctuation character for use in the `PRINT_OPERAND' macro.  */
974 extern char arc_punct_chars[256];
975 #define PRINT_OPERAND_PUNCT_VALID_P(CHAR) \
976 arc_punct_chars[(unsigned char) (CHAR)]
977 
978 /* Print operand X (an rtx) in assembler syntax to file FILE.
979    CODE is a letter or dot (`z' in `%z0') or 0 if no letter was specified.
980    For `%' followed by punctuation, CODE is the punctuation and X is null.  */
981 #define PRINT_OPERAND(FILE, X, CODE) \
982 arc_print_operand (FILE, X, CODE)
983 
984 /* A C compound statement to output to stdio stream STREAM the
985    assembler syntax for an instruction operand that is a memory
986    reference whose address is ADDR.  ADDR is an RTL expression.  */
987 #define PRINT_OPERAND_ADDRESS(FILE, ADDR) \
988 arc_print_operand_address (FILE, ADDR)
989 
990 /* This is how to output an element of a case-vector that is absolute.  */
991 #define ASM_OUTPUT_ADDR_VEC_ELT(FILE, VALUE)  \
992 do {							\
993   char label[30];					\
994   ASM_GENERATE_INTERNAL_LABEL (label, "L", VALUE);	\
995   fprintf (FILE, "\t.word %%st(");			\
996   assemble_name (FILE, label);				\
997   fprintf (FILE, ")\n");				\
998 } while (0)
999 
1000 /* This is how to output an element of a case-vector that is relative.  */
1001 #define ASM_OUTPUT_ADDR_DIFF_ELT(FILE, BODY, VALUE, REL) \
1002 do {							\
1003   char label[30];					\
1004   ASM_GENERATE_INTERNAL_LABEL (label, "L", VALUE);	\
1005   fprintf (FILE, "\t.word %%st(");			\
1006   assemble_name (FILE, label);				\
1007   fprintf (FILE, "-");					\
1008   ASM_GENERATE_INTERNAL_LABEL (label, "L", REL);	\
1009   assemble_name (FILE, label);				\
1010   fprintf (FILE, ")\n");				\
1011 } while (0)
1012 
1013 /* The desired alignment for the location counter at the beginning
1014    of a loop.  */
1015 /* On the ARC, align loops to 32 byte boundaries (cache line size)
1016    if -malign-loops.  */
1017 #define LOOP_ALIGN(LABEL) (TARGET_ALIGN_LOOPS ? 5 : 0)
1018 
1019 /* This is how to output an assembler line
1020    that says to advance the location counter
1021    to a multiple of 2**LOG bytes.  */
1022 #define ASM_OUTPUT_ALIGN(FILE,LOG) \
1023 do { if ((LOG) != 0) fprintf (FILE, "\t.align %d\n", 1 << (LOG)); } while (0)
1024 
1025 /* Debugging information.  */
1026 
1027 /* Generate DBX and DWARF debugging information.  */
1028 #define DBX_DEBUGGING_INFO 1
1029 
1030 /* Prefer STABS (for now).  */
1031 #undef PREFERRED_DEBUGGING_TYPE
1032 #define PREFERRED_DEBUGGING_TYPE DBX_DEBUG
1033 
1034 /* Turn off splitting of long stabs.  */
1035 #define DBX_CONTIN_LENGTH 0
1036 
1037 /* Miscellaneous.  */
1038 
1039 /* Specify the machine mode that this machine uses
1040    for the index in the tablejump instruction.  */
1041 #define CASE_VECTOR_MODE Pmode
1042 
1043 /* Define if operations between registers always perform the operation
1044    on the full register even if a narrower mode is specified.  */
1045 #define WORD_REGISTER_OPERATIONS
1046 
1047 /* Define if loading in MODE, an integral mode narrower than BITS_PER_WORD
1048    will either zero-extend or sign-extend.  The value of this macro should
1049    be the code that says which one of the two operations is implicitly
1050    done, UNKNOWN if none.  */
1051 #define LOAD_EXTEND_OP(MODE) ZERO_EXTEND
1052 
1053 /* Max number of bytes we can move from memory to memory
1054    in one reasonably fast instruction.  */
1055 #define MOVE_MAX 4
1056 
1057 /* Define this to be nonzero if shift instructions ignore all but the low-order
1058    few bits.  */
1059 #define SHIFT_COUNT_TRUNCATED 1
1060 
1061 /* Value is 1 if truncating an integer of INPREC bits to OUTPREC bits
1062    is done just by pretending it is already truncated.  */
1063 #define TRULY_NOOP_TRUNCATION(OUTPREC, INPREC) 1
1064 
1065 /* Specify the machine mode that pointers have.
1066    After generation of rtl, the compiler makes no further distinction
1067    between pointers and any other objects of this machine mode.  */
1068 /* ??? The arc doesn't have full 32 bit pointers, but making this PSImode has
1069    its own problems (you have to add extendpsisi2 and trucnsipsi2 but how does
1070    one do it without getting excess code?).  Try to avoid it.  */
1071 #define Pmode SImode
1072 
1073 /* A function address in a call instruction.  */
1074 #define FUNCTION_MODE SImode
1075 
1076 /* alloca should avoid clobbering the old register save area.  */
1077 /* ??? Not defined in tm.texi.  */
1078 #define SETJMP_VIA_SAVE_AREA
1079 
1080 /* Define the information needed to generate branch and scc insns.  This is
1081    stored from the compare operation.  Note that we can't use "rtx" here
1082    since it hasn't been defined!  */
1083 extern struct rtx_def *arc_compare_op0, *arc_compare_op1;
1084 
1085 /* ARC function types.  */
1086 enum arc_function_type {
1087   ARC_FUNCTION_UNKNOWN, ARC_FUNCTION_NORMAL,
1088   /* These are interrupt handlers.  The name corresponds to the register
1089      name that contains the return address.  */
1090   ARC_FUNCTION_ILINK1, ARC_FUNCTION_ILINK2
1091 };
1092 #define ARC_INTERRUPT_P(TYPE) \
1093 ((TYPE) == ARC_FUNCTION_ILINK1 || (TYPE) == ARC_FUNCTION_ILINK2)
1094 /* Compute the type of a function from its DECL.  */
1095 
1096 
1097 /* Implement `va_start' for varargs and stdarg.  */
1098 #define EXPAND_BUILTIN_VA_START(valist, nextarg) \
1099   arc_va_start (valist, nextarg)
1100