xref: /openbsd/gnu/gcc/gcc/config/alpha/alpha.h (revision a38e851f)
1 /* Definitions of target machine for GNU compiler, for DEC Alpha.
2    Copyright (C) 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999,
3    2000, 2001, 2002, 2004, 2005 Free Software Foundation, Inc.
4    Contributed by Richard Kenner (kenner@vlsi1.ultra.nyu.edu)
5 
6 This file is part of GCC.
7 
8 GCC is free software; you can redistribute it and/or modify
9 it under the terms of the GNU General Public License as published by
10 the Free Software Foundation; either version 2, or (at your option)
11 any later version.
12 
13 GCC is distributed in the hope that it will be useful,
14 but WITHOUT ANY WARRANTY; without even the implied warranty of
15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
16 GNU General Public License for more details.
17 
18 You should have received a copy of the GNU General Public License
19 along with GCC; see the file COPYING.  If not, write to
20 the Free Software Foundation, 51 Franklin Street, Fifth Floor,
21 Boston, MA 02110-1301, USA.  */
22 
23 /* Target CPU builtins.  */
24 #define TARGET_CPU_CPP_BUILTINS()			\
25   do							\
26     {							\
27 	builtin_define ("__alpha");			\
28 	builtin_define ("__alpha__");			\
29 	builtin_assert ("cpu=alpha");			\
30 	builtin_assert ("machine=alpha");		\
31 	if (TARGET_CIX)					\
32 	  {						\
33 	    builtin_define ("__alpha_cix__");		\
34 	    builtin_assert ("cpu=cix");			\
35 	  }						\
36 	if (TARGET_FIX)					\
37 	  {						\
38 	    builtin_define ("__alpha_fix__");		\
39 	    builtin_assert ("cpu=fix");			\
40 	  }						\
41 	if (TARGET_BWX)					\
42 	  {						\
43 	    builtin_define ("__alpha_bwx__");		\
44 	    builtin_assert ("cpu=bwx");			\
45 	  }						\
46 	if (TARGET_MAX)					\
47 	  {						\
48 	    builtin_define ("__alpha_max__");		\
49 	    builtin_assert ("cpu=max");			\
50 	  }						\
51 	if (alpha_cpu == PROCESSOR_EV6)			\
52 	  {						\
53 	    builtin_define ("__alpha_ev6__");		\
54 	    builtin_assert ("cpu=ev6");			\
55 	  }						\
56 	else if (alpha_cpu == PROCESSOR_EV5)		\
57 	  {						\
58 	    builtin_define ("__alpha_ev5__");		\
59 	    builtin_assert ("cpu=ev5");			\
60 	  }						\
61 	else	/* Presumably ev4.  */			\
62 	  {						\
63 	    builtin_define ("__alpha_ev4__");		\
64 	    builtin_assert ("cpu=ev4");			\
65 	  }						\
66 	if (TARGET_IEEE || TARGET_IEEE_WITH_INEXACT)	\
67 	  builtin_define ("_IEEE_FP");			\
68 	if (TARGET_IEEE_WITH_INEXACT)			\
69 	  builtin_define ("_IEEE_FP_INEXACT");		\
70 	if (TARGET_LONG_DOUBLE_128)			\
71 	  builtin_define ("__LONG_DOUBLE_128__");	\
72 							\
73 	/* Macros dependent on the C dialect.  */	\
74 	SUBTARGET_LANGUAGE_CPP_BUILTINS();		\
75 } while (0)
76 
77 #ifndef SUBTARGET_LANGUAGE_CPP_BUILTINS
78 #define SUBTARGET_LANGUAGE_CPP_BUILTINS()		\
79   do							\
80     {							\
81       if (preprocessing_asm_p ())			\
82 	builtin_define_std ("LANGUAGE_ASSEMBLY");	\
83       else if (c_dialect_cxx ())			\
84 	{						\
85 	  builtin_define ("__LANGUAGE_C_PLUS_PLUS");	\
86 	  builtin_define ("__LANGUAGE_C_PLUS_PLUS__");	\
87 	}						\
88       else						\
89 	builtin_define_std ("LANGUAGE_C");		\
90       if (c_dialect_objc ())				\
91 	{						\
92 	  builtin_define ("__LANGUAGE_OBJECTIVE_C");	\
93 	  builtin_define ("__LANGUAGE_OBJECTIVE_C__");	\
94 	}						\
95     }							\
96   while (0)
97 #endif
98 
99 #define CPP_SPEC "%(cpp_subtarget)"
100 
101 #ifndef CPP_SUBTARGET_SPEC
102 #define CPP_SUBTARGET_SPEC ""
103 #endif
104 
105 #define WORD_SWITCH_TAKES_ARG(STR)		\
106  (!strcmp (STR, "rpath") || DEFAULT_WORD_SWITCH_TAKES_ARG(STR))
107 
108 /* Print subsidiary information on the compiler version in use.  */
109 #define TARGET_VERSION
110 
111 /* Run-time compilation parameters selecting different hardware subsets.  */
112 
113 /* Which processor to schedule for. The cpu attribute defines a list that
114    mirrors this list, so changes to alpha.md must be made at the same time.  */
115 
116 enum processor_type
117 {
118   PROCESSOR_EV4,			/* 2106[46]{a,} */
119   PROCESSOR_EV5,			/* 21164{a,pc,} */
120   PROCESSOR_EV6,			/* 21264 */
121   PROCESSOR_MAX
122 };
123 
124 extern enum processor_type alpha_cpu;
125 extern enum processor_type alpha_tune;
126 
127 enum alpha_trap_precision
128 {
129   ALPHA_TP_PROG,	/* No precision (default).  */
130   ALPHA_TP_FUNC,      	/* Trap contained within originating function.  */
131   ALPHA_TP_INSN		/* Instruction accuracy and code is resumption safe.  */
132 };
133 
134 enum alpha_fp_rounding_mode
135 {
136   ALPHA_FPRM_NORM,	/* Normal rounding mode.  */
137   ALPHA_FPRM_MINF,	/* Round towards minus-infinity.  */
138   ALPHA_FPRM_CHOP,	/* Chopped rounding mode (towards 0).  */
139   ALPHA_FPRM_DYN	/* Dynamic rounding mode.  */
140 };
141 
142 enum alpha_fp_trap_mode
143 {
144   ALPHA_FPTM_N,		/* Normal trap mode.  */
145   ALPHA_FPTM_U,		/* Underflow traps enabled.  */
146   ALPHA_FPTM_SU,	/* Software completion, w/underflow traps */
147   ALPHA_FPTM_SUI	/* Software completion, w/underflow & inexact traps */
148 };
149 
150 extern int target_flags;
151 
152 extern enum alpha_trap_precision alpha_tp;
153 extern enum alpha_fp_rounding_mode alpha_fprm;
154 extern enum alpha_fp_trap_mode alpha_fptm;
155 
156 /* Invert the easy way to make options work.  */
157 #define TARGET_FP	(!TARGET_SOFT_FP)
158 
159 /* These are for target os support and cannot be changed at runtime.  */
160 #define TARGET_ABI_WINDOWS_NT 0
161 #define TARGET_ABI_OPEN_VMS 0
162 #define TARGET_ABI_UNICOSMK 0
163 #define TARGET_ABI_OSF (!TARGET_ABI_WINDOWS_NT	\
164 			&& !TARGET_ABI_OPEN_VMS	\
165 			&& !TARGET_ABI_UNICOSMK)
166 
167 #ifndef TARGET_AS_CAN_SUBTRACT_LABELS
168 #define TARGET_AS_CAN_SUBTRACT_LABELS TARGET_GAS
169 #endif
170 #ifndef TARGET_AS_SLASH_BEFORE_SUFFIX
171 #define TARGET_AS_SLASH_BEFORE_SUFFIX TARGET_GAS
172 #endif
173 #ifndef TARGET_CAN_FAULT_IN_PROLOGUE
174 #define TARGET_CAN_FAULT_IN_PROLOGUE 0
175 #endif
176 #ifndef TARGET_HAS_XFLOATING_LIBS
177 #define TARGET_HAS_XFLOATING_LIBS TARGET_LONG_DOUBLE_128
178 #endif
179 #ifndef TARGET_PROFILING_NEEDS_GP
180 #define TARGET_PROFILING_NEEDS_GP 0
181 #endif
182 #ifndef TARGET_LD_BUGGY_LDGP
183 #define TARGET_LD_BUGGY_LDGP 0
184 #endif
185 #ifndef TARGET_FIXUP_EV5_PREFETCH
186 #define TARGET_FIXUP_EV5_PREFETCH 0
187 #endif
188 #ifndef HAVE_AS_TLS
189 #define HAVE_AS_TLS 0
190 #endif
191 
192 #define TARGET_DEFAULT MASK_FPREGS
193 
194 #ifndef TARGET_CPU_DEFAULT
195 #define TARGET_CPU_DEFAULT 0
196 #endif
197 
198 #ifndef TARGET_DEFAULT_EXPLICIT_RELOCS
199 #ifdef HAVE_AS_EXPLICIT_RELOCS
200 #define TARGET_DEFAULT_EXPLICIT_RELOCS MASK_EXPLICIT_RELOCS
201 #define TARGET_SUPPORT_ARCH 1
202 #else
203 #define TARGET_DEFAULT_EXPLICIT_RELOCS 0
204 #endif
205 #endif
206 
207 #ifndef TARGET_SUPPORT_ARCH
208 #define TARGET_SUPPORT_ARCH 0
209 #endif
210 
211 /* Support for a compile-time default CPU, et cetera.  The rules are:
212    --with-cpu is ignored if -mcpu is specified.
213    --with-tune is ignored if -mtune is specified.  */
214 #define OPTION_DEFAULT_SPECS \
215   {"cpu", "%{!mcpu=*:-mcpu=%(VALUE)}" }, \
216   {"tune", "%{!mtune=*:-mtune=%(VALUE)}" }
217 
218 /* This macro defines names of additional specifications to put in the
219    specs that can be used in various specifications like CC1_SPEC.  Its
220    definition is an initializer with a subgrouping for each command option.
221 
222    Each subgrouping contains a string constant, that defines the
223    specification name, and a string constant that used by the GCC driver
224    program.
225 
226    Do not define this macro if it does not need to do anything.  */
227 
228 #ifndef SUBTARGET_EXTRA_SPECS
229 #define SUBTARGET_EXTRA_SPECS
230 #endif
231 
232 #define EXTRA_SPECS				\
233   { "cpp_subtarget", CPP_SUBTARGET_SPEC },	\
234   SUBTARGET_EXTRA_SPECS
235 
236 
237 /* Sometimes certain combinations of command options do not make sense
238    on a particular target machine.  You can define a macro
239    `OVERRIDE_OPTIONS' to take account of this.  This macro, if
240    defined, is executed once just after all the command options have
241    been parsed.
242 
243    On the Alpha, it is used to translate target-option strings into
244    numeric values.  */
245 
246 #define OVERRIDE_OPTIONS override_options ()
247 
248 
249 /* Define this macro to change register usage conditional on target flags.
250 
251    On the Alpha, we use this to disable the floating-point registers when
252    they don't exist.  */
253 
254 #define CONDITIONAL_REGISTER_USAGE		\
255 {						\
256   int i;					\
257   if (! TARGET_FPREGS)				\
258     for (i = 32; i < 63; i++)			\
259       fixed_regs[i] = call_used_regs[i] = 1;	\
260 }
261 
262 
263 /* Show we can debug even without a frame pointer.  */
264 #define CAN_DEBUG_WITHOUT_FP
265 
266 /* target machine storage layout */
267 
268 /* Define the size of `int'.  The default is the same as the word size.  */
269 #define INT_TYPE_SIZE 32
270 
271 /* Define the size of `long long'.  The default is the twice the word size.  */
272 #define LONG_LONG_TYPE_SIZE 64
273 
274 /* We're IEEE unless someone says to use VAX.  */
275 #define TARGET_FLOAT_FORMAT \
276   (TARGET_FLOAT_VAX ? VAX_FLOAT_FORMAT : IEEE_FLOAT_FORMAT)
277 
278 /* The two floating-point formats we support are S-floating, which is
279    4 bytes, and T-floating, which is 8 bytes.  `float' is S and `double'
280    and `long double' are T.  */
281 
282 #define FLOAT_TYPE_SIZE 32
283 #define DOUBLE_TYPE_SIZE 64
284 #define LONG_DOUBLE_TYPE_SIZE (TARGET_LONG_DOUBLE_128 ? 128 : 64)
285 
286 /* Define this to set long double type size to use in libgcc2.c, which can
287    not depend on target_flags.  */
288 #ifdef __LONG_DOUBLE_128__
289 #define LIBGCC2_LONG_DOUBLE_TYPE_SIZE 128
290 #else
291 #define LIBGCC2_LONG_DOUBLE_TYPE_SIZE 64
292 #endif
293 
294 /* Work around target_flags dependency in ada/targtyps.c.  */
295 #define WIDEST_HARDWARE_FP_SIZE 64
296 
297 #define	WCHAR_TYPE "unsigned int"
298 #define	WCHAR_TYPE_SIZE 32
299 
300 /* Define this macro if it is advisable to hold scalars in registers
301    in a wider mode than that declared by the program.  In such cases,
302    the value is constrained to be within the bounds of the declared
303    type, but kept valid in the wider mode.  The signedness of the
304    extension may differ from that of the type.
305 
306    For Alpha, we always store objects in a full register.  32-bit integers
307    are always sign-extended, but smaller objects retain their signedness.
308 
309    Note that small vector types can get mapped onto integer modes at the
310    whim of not appearing in alpha-modes.def.  We never promoted these
311    values before; don't do so now that we've trimmed the set of modes to
312    those actually implemented in the backend.  */
313 
314 #define PROMOTE_MODE(MODE,UNSIGNEDP,TYPE)			\
315   if (GET_MODE_CLASS (MODE) == MODE_INT				\
316       && (TYPE == NULL || TREE_CODE (TYPE) != VECTOR_TYPE)	\
317       && GET_MODE_SIZE (MODE) < UNITS_PER_WORD)			\
318     {								\
319       if ((MODE) == SImode)					\
320 	(UNSIGNEDP) = 0;					\
321       (MODE) = DImode;						\
322     }
323 
324 /* Define this if most significant bit is lowest numbered
325    in instructions that operate on numbered bit-fields.
326 
327    There are no such instructions on the Alpha, but the documentation
328    is little endian.  */
329 #define BITS_BIG_ENDIAN 0
330 
331 /* Define this if most significant byte of a word is the lowest numbered.
332    This is false on the Alpha.  */
333 #define BYTES_BIG_ENDIAN 0
334 
335 /* Define this if most significant word of a multiword number is lowest
336    numbered.
337 
338    For Alpha we can decide arbitrarily since there are no machine instructions
339    for them.  Might as well be consistent with bytes.  */
340 #define WORDS_BIG_ENDIAN 0
341 
342 /* Width of a word, in units (bytes).  */
343 #define UNITS_PER_WORD 8
344 
345 /* Width in bits of a pointer.
346    See also the macro `Pmode' defined below.  */
347 #define POINTER_SIZE 64
348 
349 /* Allocation boundary (in *bits*) for storing arguments in argument list.  */
350 #define PARM_BOUNDARY 64
351 
352 /* Boundary (in *bits*) on which stack pointer should be aligned.  */
353 #define STACK_BOUNDARY 128
354 
355 /* Allocation boundary (in *bits*) for the code of a function.  */
356 #define FUNCTION_BOUNDARY 32
357 
358 /* Alignment of field after `int : 0' in a structure.  */
359 #define EMPTY_FIELD_BOUNDARY 64
360 
361 /* Every structure's size must be a multiple of this.  */
362 #define STRUCTURE_SIZE_BOUNDARY 8
363 
364 /* A bit-field declared as `int' forces `int' alignment for the struct.  */
365 #define PCC_BITFIELD_TYPE_MATTERS 1
366 
367 /* No data type wants to be aligned rounder than this.  */
368 #define BIGGEST_ALIGNMENT 128
369 
370 /* For atomic access to objects, must have at least 32-bit alignment
371    unless the machine has byte operations.  */
372 #define MINIMUM_ATOMIC_ALIGNMENT ((unsigned int) (TARGET_BWX ? 8 : 32))
373 
374 /* Align all constants and variables to at least a word boundary so
375    we can pick up pieces of them faster.  */
376 #define CONSTANT_ALIGNMENT(EXP, ALIGN) MAX ((ALIGN), BITS_PER_WORD)
377 #define DATA_ALIGNMENT(EXP, ALIGN) MAX ((ALIGN), BITS_PER_WORD)
378 
379 /* Make local arrays of chars word-aligned for the same reasons.  */
380 #define LOCAL_ALIGNMENT(TYPE, ALIGN) DATA_ALIGNMENT (TYPE, ALIGN)
381 
382 /* Set this nonzero if move instructions will actually fail to work
383    when given unaligned data.
384 
385    Since we get an error message when we do one, call them invalid.  */
386 
387 #define STRICT_ALIGNMENT 1
388 
389 /* Set this nonzero if unaligned move instructions are extremely slow.
390 
391    On the Alpha, they trap.  */
392 
393 #define SLOW_UNALIGNED_ACCESS(MODE, ALIGN) 1
394 
395 /* Standard register usage.  */
396 
397 /* Number of actual hardware registers.
398    The hardware registers are assigned numbers for the compiler
399    from 0 to just below FIRST_PSEUDO_REGISTER.
400    All registers that the compiler knows about must be given numbers,
401    even those that are not normally considered general registers.
402 
403    We define all 32 integer registers, even though $31 is always zero,
404    and all 32 floating-point registers, even though $f31 is also
405    always zero.  We do not bother defining the FP status register and
406    there are no other registers.
407 
408    Since $31 is always zero, we will use register number 31 as the
409    argument pointer.  It will never appear in the generated code
410    because we will always be eliminating it in favor of the stack
411    pointer or hardware frame pointer.
412 
413    Likewise, we use $f31 for the frame pointer, which will always
414    be eliminated in favor of the hardware frame pointer or the
415    stack pointer.  */
416 
417 #define FIRST_PSEUDO_REGISTER 64
418 
419 /* 1 for registers that have pervasive standard uses
420    and are not available for the register allocator.  */
421 
422 #define FIXED_REGISTERS  \
423  {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, \
424   0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, \
425   0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, \
426   0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1 }
427 
428 /* 1 for registers not available across function calls.
429    These must include the FIXED_REGISTERS and also any
430    registers that can be used without being saved.
431    The latter must include the registers where values are returned
432    and the register where structure-value addresses are passed.
433    Aside from that, you can include as many other registers as you like.  */
434 #define CALL_USED_REGISTERS  \
435  {1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0, \
436   1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 1, 1, 1, 1, 1, \
437   1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 1, \
438   1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1 }
439 
440 /* List the order in which to allocate registers.  Each register must be
441    listed once, even those in FIXED_REGISTERS.  */
442 
443 #define REG_ALLOC_ORDER { \
444    1, 2, 3, 4, 5, 6, 7, 8,	/* nonsaved integer registers */	\
445    22, 23, 24, 25, 28,		/* likewise */				\
446    0,				/* likewise, but return value */	\
447    21, 20, 19, 18, 17, 16,	/* likewise, but input args */		\
448    27,				/* likewise, but OSF procedure value */	\
449 									\
450    42, 43, 44, 45, 46, 47,	/* nonsaved floating-point registers */	\
451    54, 55, 56, 57, 58, 59,	/* likewise */				\
452    60, 61, 62,			/* likewise */				\
453    32, 33,			/* likewise, but return values */	\
454    53, 52, 51, 50, 49, 48,	/* likewise, but input args */		\
455 									\
456    9, 10, 11, 12, 13, 14,	/* saved integer registers */		\
457    26,				/* return address */			\
458    15,				/* hard frame pointer */		\
459 									\
460    34, 35, 36, 37, 38, 39,	/* saved floating-point registers */	\
461    40, 41,			/* likewise */				\
462 									\
463    29, 30, 31, 63		/* gp, sp, ap, sfp */			\
464 }
465 
466 /* Return number of consecutive hard regs needed starting at reg REGNO
467    to hold something of mode MODE.
468    This is ordinarily the length in words of a value of mode MODE
469    but can be less for certain modes in special long registers.  */
470 
471 #define HARD_REGNO_NREGS(REGNO, MODE)   \
472   ((GET_MODE_SIZE (MODE) + UNITS_PER_WORD - 1) / UNITS_PER_WORD)
473 
474 /* Value is 1 if hard register REGNO can hold a value of machine-mode MODE.
475    On Alpha, the integer registers can hold any mode.  The floating-point
476    registers can hold 64-bit integers as well, but not smaller values.  */
477 
478 #define HARD_REGNO_MODE_OK(REGNO, MODE) 				\
479   ((REGNO) >= 32 && (REGNO) <= 62 					\
480    ? (MODE) == SFmode || (MODE) == DFmode || (MODE) == DImode		\
481      || (MODE) == SCmode || (MODE) == DCmode				\
482    : 1)
483 
484 /* A C expression that is nonzero if a value of mode
485    MODE1 is accessible in mode MODE2 without copying.
486 
487    This asymmetric test is true when MODE1 could be put
488    in an FP register but MODE2 could not.  */
489 
490 #define MODES_TIEABLE_P(MODE1, MODE2) 				\
491   (HARD_REGNO_MODE_OK (32, (MODE1))				\
492    ? HARD_REGNO_MODE_OK (32, (MODE2))				\
493    : 1)
494 
495 /* Specify the registers used for certain standard purposes.
496    The values of these macros are register numbers.  */
497 
498 /* Alpha pc isn't overloaded on a register that the compiler knows about.  */
499 /* #define PC_REGNUM  */
500 
501 /* Register to use for pushing function arguments.  */
502 #define STACK_POINTER_REGNUM 30
503 
504 /* Base register for access to local variables of the function.  */
505 #define HARD_FRAME_POINTER_REGNUM 15
506 
507 /* Value should be nonzero if functions must have frame pointers.
508    Zero means the frame pointer need not be set up (and parms
509    may be accessed via the stack pointer) in functions that seem suitable.
510    This is computed in `reload', in reload1.c.  */
511 #define FRAME_POINTER_REQUIRED 0
512 
513 /* Base register for access to arguments of the function.  */
514 #define ARG_POINTER_REGNUM 31
515 
516 /* Base register for access to local variables of function.  */
517 #define FRAME_POINTER_REGNUM 63
518 
519 /* Register in which static-chain is passed to a function.
520 
521    For the Alpha, this is based on an example; the calling sequence
522    doesn't seem to specify this.  */
523 #define STATIC_CHAIN_REGNUM 1
524 
525 /* The register number of the register used to address a table of
526    static data addresses in memory.  */
527 #define PIC_OFFSET_TABLE_REGNUM 29
528 
529 /* Define this macro if the register defined by `PIC_OFFSET_TABLE_REGNUM'
530    is clobbered by calls.  */
531 /* ??? It is and it isn't.  It's required to be valid for a given
532    function when the function returns.  It isn't clobbered by
533    current_file functions.  Moreover, we do not expose the ldgp
534    until after reload, so we're probably safe.  */
535 /* #define PIC_OFFSET_TABLE_REG_CALL_CLOBBERED */
536 
537 /* Define the classes of registers for register constraints in the
538    machine description.  Also define ranges of constants.
539 
540    One of the classes must always be named ALL_REGS and include all hard regs.
541    If there is more than one class, another class must be named NO_REGS
542    and contain no registers.
543 
544    The name GENERAL_REGS must be the name of a class (or an alias for
545    another name such as ALL_REGS).  This is the class of registers
546    that is allowed by "g" or "r" in a register constraint.
547    Also, registers outside this class are allocated only when
548    instructions express preferences for them.
549 
550    The classes must be numbered in nondecreasing order; that is,
551    a larger-numbered class must never be contained completely
552    in a smaller-numbered class.
553 
554    For any two classes, it is very desirable that there be another
555    class that represents their union.  */
556 
557 enum reg_class {
558   NO_REGS, R0_REG, R24_REG, R25_REG, R27_REG,
559   GENERAL_REGS, FLOAT_REGS, ALL_REGS,
560   LIM_REG_CLASSES
561 };
562 
563 #define N_REG_CLASSES (int) LIM_REG_CLASSES
564 
565 /* Give names of register classes as strings for dump file.  */
566 
567 #define REG_CLASS_NAMES					\
568  {"NO_REGS", "R0_REG", "R24_REG", "R25_REG", "R27_REG",	\
569   "GENERAL_REGS", "FLOAT_REGS", "ALL_REGS" }
570 
571 /* Define which registers fit in which classes.
572    This is an initializer for a vector of HARD_REG_SET
573    of length N_REG_CLASSES.  */
574 
575 #define REG_CLASS_CONTENTS				\
576 { {0x00000000, 0x00000000},	/* NO_REGS */		\
577   {0x00000001, 0x00000000},	/* R0_REG */		\
578   {0x01000000, 0x00000000},	/* R24_REG */		\
579   {0x02000000, 0x00000000},	/* R25_REG */		\
580   {0x08000000, 0x00000000},	/* R27_REG */		\
581   {0xffffffff, 0x80000000},	/* GENERAL_REGS */	\
582   {0x00000000, 0x7fffffff},	/* FLOAT_REGS */	\
583   {0xffffffff, 0xffffffff} }
584 
585 /* The same information, inverted:
586    Return the class number of the smallest class containing
587    reg number REGNO.  This could be a conditional expression
588    or could index an array.  */
589 
590 #define REGNO_REG_CLASS(REGNO)			\
591  ((REGNO) == 0 ? R0_REG				\
592   : (REGNO) == 24 ? R24_REG			\
593   : (REGNO) == 25 ? R25_REG			\
594   : (REGNO) == 27 ? R27_REG			\
595   : (REGNO) >= 32 && (REGNO) <= 62 ? FLOAT_REGS	\
596   : GENERAL_REGS)
597 
598 /* The class value for index registers, and the one for base regs.  */
599 #define INDEX_REG_CLASS NO_REGS
600 #define BASE_REG_CLASS GENERAL_REGS
601 
602 /* Get reg_class from a letter such as appears in the machine description.  */
603 
604 #define REG_CLASS_FROM_LETTER(C)	\
605  ((C) == 'a' ? R24_REG			\
606   : (C) == 'b' ? R25_REG		\
607   : (C) == 'c' ? R27_REG		\
608   : (C) == 'f' ? FLOAT_REGS		\
609   : (C) == 'v' ? R0_REG			\
610   : NO_REGS)
611 
612 /* Define this macro to change register usage conditional on target flags.  */
613 /* #define CONDITIONAL_REGISTER_USAGE  */
614 
615 /* The letters I, J, K, L, M, N, O, and P in a register constraint string
616    can be used to stand for particular ranges of immediate operands.
617    This macro defines what the ranges are.
618    C is the letter, and VALUE is a constant value.
619    Return 1 if VALUE is in the range specified by C.
620 
621    For Alpha:
622    `I' is used for the range of constants most insns can contain.
623    `J' is the constant zero.
624    `K' is used for the constant in an LDA insn.
625    `L' is used for the constant in a LDAH insn.
626    `M' is used for the constants that can be AND'ed with using a ZAP insn.
627    `N' is used for complemented 8-bit constants.
628    `O' is used for negated 8-bit constants.
629    `P' is used for the constants 1, 2 and 3.  */
630 
631 #define CONST_OK_FOR_LETTER_P   alpha_const_ok_for_letter_p
632 
633 /* Similar, but for floating or large integer constants, and defining letters
634    G and H.   Here VALUE is the CONST_DOUBLE rtx itself.
635 
636    For Alpha, `G' is the floating-point constant zero.  `H' is a CONST_DOUBLE
637    that is the operand of a ZAP insn.  */
638 
639 #define CONST_DOUBLE_OK_FOR_LETTER_P  alpha_const_double_ok_for_letter_p
640 
641 /* Optional extra constraints for this machine.
642 
643    For the Alpha, `Q' means that this is a memory operand but not a
644    reference to an unaligned location.
645 
646    `R' is a SYMBOL_REF that has SYMBOL_REF_FLAG set or is the current
647    function.
648 
649    'S' is a 6-bit constant (valid for a shift insn).
650 
651    'T' is a HIGH.
652 
653    'U' is a symbolic operand.
654 
655    'W' is a vector zero.  */
656 
657 #define EXTRA_CONSTRAINT  alpha_extra_constraint
658 
659 /* Given an rtx X being reloaded into a reg required to be
660    in class CLASS, return the class of reg to actually use.
661    In general this is just CLASS; but on some machines
662    in some cases it is preferable to use a more restrictive class.  */
663 
664 #define PREFERRED_RELOAD_CLASS  alpha_preferred_reload_class
665 
666 /* Loading and storing HImode or QImode values to and from memory
667    usually requires a scratch register.  The exceptions are loading
668    QImode and HImode from an aligned address to a general register
669    unless byte instructions are permitted.
670    We also cannot load an unaligned address or a paradoxical SUBREG into an
671    FP register.  */
672 
673 #define SECONDARY_INPUT_RELOAD_CLASS(CLASS,MODE,IN) \
674   alpha_secondary_reload_class((CLASS), (MODE), (IN), 1)
675 
676 #define SECONDARY_OUTPUT_RELOAD_CLASS(CLASS,MODE,OUT) \
677   alpha_secondary_reload_class((CLASS), (MODE), (OUT), 0)
678 
679 /* If we are copying between general and FP registers, we need a memory
680    location unless the FIX extension is available.  */
681 
682 #define SECONDARY_MEMORY_NEEDED(CLASS1,CLASS2,MODE) \
683  (! TARGET_FIX && (((CLASS1) == FLOAT_REGS && (CLASS2) != FLOAT_REGS) \
684                    || ((CLASS2) == FLOAT_REGS && (CLASS1) != FLOAT_REGS)))
685 
686 /* Specify the mode to be used for memory when a secondary memory
687    location is needed.  If MODE is floating-point, use it.  Otherwise,
688    widen to a word like the default.  This is needed because we always
689    store integers in FP registers in quadword format.  This whole
690    area is very tricky! */
691 #define SECONDARY_MEMORY_NEEDED_MODE(MODE)		\
692   (GET_MODE_CLASS (MODE) == MODE_FLOAT ? (MODE)		\
693    : GET_MODE_SIZE (MODE) >= 4 ? (MODE)			\
694    : mode_for_size (BITS_PER_WORD, GET_MODE_CLASS (MODE), 0))
695 
696 /* Return the maximum number of consecutive registers
697    needed to represent mode MODE in a register of class CLASS.  */
698 
699 #define CLASS_MAX_NREGS(CLASS, MODE)				\
700  ((GET_MODE_SIZE (MODE) + UNITS_PER_WORD - 1) / UNITS_PER_WORD)
701 
702 /* Return the class of registers that cannot change mode from FROM to TO.  */
703 
704 #define CANNOT_CHANGE_MODE_CLASS(FROM, TO, CLASS)		\
705   (GET_MODE_SIZE (FROM) != GET_MODE_SIZE (TO)			\
706    ? reg_classes_intersect_p (FLOAT_REGS, CLASS) : 0)
707 
708 /* Define the cost of moving between registers of various classes.  Moving
709    between FLOAT_REGS and anything else except float regs is expensive.
710    In fact, we make it quite expensive because we really don't want to
711    do these moves unless it is clearly worth it.  Optimizations may
712    reduce the impact of not being able to allocate a pseudo to a
713    hard register.  */
714 
715 #define REGISTER_MOVE_COST(MODE, CLASS1, CLASS2)		\
716   (((CLASS1) == FLOAT_REGS) == ((CLASS2) == FLOAT_REGS)	? 2	\
717    : TARGET_FIX ? ((CLASS1) == FLOAT_REGS ? 6 : 8)		\
718    : 4+2*alpha_memory_latency)
719 
720 /* A C expressions returning the cost of moving data of MODE from a register to
721    or from memory.
722 
723    On the Alpha, bump this up a bit.  */
724 
725 extern int alpha_memory_latency;
726 #define MEMORY_MOVE_COST(MODE,CLASS,IN)  (2*alpha_memory_latency)
727 
728 /* Provide the cost of a branch.  Exact meaning under development.  */
729 #define BRANCH_COST 5
730 
731 /* Stack layout; function entry, exit and calling.  */
732 
733 /* Define this if pushing a word on the stack
734    makes the stack pointer a smaller address.  */
735 #define STACK_GROWS_DOWNWARD
736 
737 /* Define this to nonzero if the nominal address of the stack frame
738    is at the high-address end of the local variables;
739    that is, each additional local variable allocated
740    goes at a more negative offset in the frame.  */
741 #define FRAME_GROWS_DOWNWARD 1
742 
743 /* Offset within stack frame to start allocating local variables at.
744    If FRAME_GROWS_DOWNWARD, this is the offset to the END of the
745    first local allocated.  Otherwise, it is the offset to the BEGINNING
746    of the first local allocated.  */
747 
748 #define STARTING_FRAME_OFFSET 0
749 
750 /* If we generate an insn to push BYTES bytes,
751    this says how many the stack pointer really advances by.
752    On Alpha, don't define this because there are no push insns.  */
753 /*  #define PUSH_ROUNDING(BYTES) */
754 
755 /* Define this to be nonzero if stack checking is built into the ABI.  */
756 #define STACK_CHECK_BUILTIN 1
757 
758 /* Define this if the maximum size of all the outgoing args is to be
759    accumulated and pushed during the prologue.  The amount can be
760    found in the variable current_function_outgoing_args_size.  */
761 #define ACCUMULATE_OUTGOING_ARGS 1
762 
763 /* Offset of first parameter from the argument pointer register value.  */
764 
765 #define FIRST_PARM_OFFSET(FNDECL) 0
766 
767 /* Definitions for register eliminations.
768 
769    We have two registers that can be eliminated on the Alpha.  First, the
770    frame pointer register can often be eliminated in favor of the stack
771    pointer register.  Secondly, the argument pointer register can always be
772    eliminated; it is replaced with either the stack or frame pointer.  */
773 
774 /* This is an array of structures.  Each structure initializes one pair
775    of eliminable registers.  The "from" register number is given first,
776    followed by "to".  Eliminations of the same "from" register are listed
777    in order of preference.  */
778 
779 #define ELIMINABLE_REGS				     \
780 {{ ARG_POINTER_REGNUM, STACK_POINTER_REGNUM},	     \
781  { ARG_POINTER_REGNUM, HARD_FRAME_POINTER_REGNUM},   \
782  { FRAME_POINTER_REGNUM, STACK_POINTER_REGNUM},	     \
783  { FRAME_POINTER_REGNUM, HARD_FRAME_POINTER_REGNUM}}
784 
785 /* Given FROM and TO register numbers, say whether this elimination is allowed.
786    Frame pointer elimination is automatically handled.
787 
788    All eliminations are valid since the cases where FP can't be
789    eliminated are already handled.  */
790 
791 #define CAN_ELIMINATE(FROM, TO) 1
792 
793 /* Round up to a multiple of 16 bytes.  */
794 #define ALPHA_ROUND(X) (((X) + 15) & ~ 15)
795 
796 /* Define the offset between two registers, one to be eliminated, and the other
797    its replacement, at the start of a routine.  */
798 #define INITIAL_ELIMINATION_OFFSET(FROM, TO, OFFSET) \
799   ((OFFSET) = alpha_initial_elimination_offset(FROM, TO))
800 
801 /* Define this if stack space is still allocated for a parameter passed
802    in a register.  */
803 /* #define REG_PARM_STACK_SPACE */
804 
805 /* Value is the number of bytes of arguments automatically
806    popped when returning from a subroutine call.
807    FUNDECL is the declaration node of the function (as a tree),
808    FUNTYPE is the data type of the function (as a tree),
809    or for a library call it is an identifier node for the subroutine name.
810    SIZE is the number of bytes of arguments passed on the stack.  */
811 
812 #define RETURN_POPS_ARGS(FUNDECL,FUNTYPE,SIZE) 0
813 
814 /* Define how to find the value returned by a function.
815    VALTYPE is the data type of the value (as a tree).
816    If the precise function being called is known, FUNC is its FUNCTION_DECL;
817    otherwise, FUNC is 0.
818 
819    On Alpha the value is found in $0 for integer functions and
820    $f0 for floating-point functions.  */
821 
822 #define FUNCTION_VALUE(VALTYPE, FUNC) \
823   function_value (VALTYPE, FUNC, VOIDmode)
824 
825 /* Define how to find the value returned by a library function
826    assuming the value has mode MODE.  */
827 
828 #define LIBCALL_VALUE(MODE) \
829   function_value (NULL, NULL, MODE)
830 
831 /* 1 if N is a possible register number for a function value
832    as seen by the caller.  */
833 
834 #define FUNCTION_VALUE_REGNO_P(N)  \
835   ((N) == 0 || (N) == 1 || (N) == 32 || (N) == 33)
836 
837 /* 1 if N is a possible register number for function argument passing.
838    On Alpha, these are $16-$21 and $f16-$f21.  */
839 
840 #define FUNCTION_ARG_REGNO_P(N) \
841   (((N) >= 16 && (N) <= 21) || ((N) >= 16 + 32 && (N) <= 21 + 32))
842 
843 /* Define a data type for recording info about an argument list
844    during the scan of that argument list.  This data type should
845    hold all necessary information about the function itself
846    and about the args processed so far, enough to enable macros
847    such as FUNCTION_ARG to determine where the next arg should go.
848 
849    On Alpha, this is a single integer, which is a number of words
850    of arguments scanned so far.
851    Thus 6 or more means all following args should go on the stack.  */
852 
853 #define CUMULATIVE_ARGS int
854 
855 /* Initialize a variable CUM of type CUMULATIVE_ARGS
856    for a call to a function whose data type is FNTYPE.
857    For a library call, FNTYPE is 0.  */
858 
859 #define INIT_CUMULATIVE_ARGS(CUM, FNTYPE, LIBNAME, INDIRECT, N_NAMED_ARGS) \
860   (CUM) = 0
861 
862 /* Define intermediate macro to compute the size (in registers) of an argument
863    for the Alpha.  */
864 
865 #define ALPHA_ARG_SIZE(MODE, TYPE, NAMED)				\
866   ((MODE) == TFmode || (MODE) == TCmode ? 1				\
867    : (((MODE) == BLKmode ? int_size_in_bytes (TYPE) : GET_MODE_SIZE (MODE)) \
868       + (UNITS_PER_WORD - 1)) / UNITS_PER_WORD)
869 
870 /* Update the data in CUM to advance over an argument
871    of mode MODE and data type TYPE.
872    (TYPE is null for libcalls where that information may not be available.)  */
873 
874 #define FUNCTION_ARG_ADVANCE(CUM, MODE, TYPE, NAMED)			\
875   ((CUM) += 								\
876    (targetm.calls.must_pass_in_stack (MODE, TYPE))			\
877     ? 6 : ALPHA_ARG_SIZE (MODE, TYPE, NAMED))
878 
879 /* Determine where to put an argument to a function.
880    Value is zero to push the argument on the stack,
881    or a hard register in which to store the argument.
882 
883    MODE is the argument's machine mode.
884    TYPE is the data type of the argument (as a tree).
885     This is null for libcalls where that information may
886     not be available.
887    CUM is a variable of type CUMULATIVE_ARGS which gives info about
888     the preceding args and about the function being called.
889    NAMED is nonzero if this argument is a named parameter
890     (otherwise it is an extra parameter matching an ellipsis).
891 
892    On Alpha the first 6 words of args are normally in registers
893    and the rest are pushed.  */
894 
895 #define FUNCTION_ARG(CUM, MODE, TYPE, NAMED)	\
896   function_arg((CUM), (MODE), (TYPE), (NAMED))
897 
898 /* Try to output insns to set TARGET equal to the constant C if it can be
899    done in less than N insns.  Do all computations in MODE.  Returns the place
900    where the output has been placed if it can be done and the insns have been
901    emitted.  If it would take more than N insns, zero is returned and no
902    insns and emitted.  */
903 
904 /* Define the information needed to generate branch and scc insns.  This is
905    stored from the compare operation.  Note that we can't use "rtx" here
906    since it hasn't been defined!  */
907 
908 struct alpha_compare
909 {
910   struct rtx_def *op0, *op1;
911   int fp_p;
912 };
913 
914 extern struct alpha_compare alpha_compare;
915 
916 /* Make (or fake) .linkage entry for function call.
917    IS_LOCAL is 0 if name is used in call, 1 if name is used in definition.  */
918 
919 /* This macro defines the start of an assembly comment.  */
920 
921 #define ASM_COMMENT_START " #"
922 
923 /* This macro produces the initial definition of a function.  */
924 
925 #define ASM_DECLARE_FUNCTION_NAME(FILE,NAME,DECL) \
926   alpha_start_function(FILE,NAME,DECL);
927 
928 /* This macro closes up a function definition for the assembler.  */
929 
930 #define ASM_DECLARE_FUNCTION_SIZE(FILE,NAME,DECL) \
931   alpha_end_function(FILE,NAME,DECL)
932 
933 /* Output any profiling code before the prologue.  */
934 
935 #define PROFILE_BEFORE_PROLOGUE 1
936 
937 /* Never use profile counters.  */
938 
939 #define NO_PROFILE_COUNTERS 1
940 
941 /* Output assembler code to FILE to increment profiler label # LABELNO
942    for profiling a function entry.  Under OSF/1, profiling is enabled
943    by simply passing -pg to the assembler and linker.  */
944 
945 #define FUNCTION_PROFILER(FILE, LABELNO)
946 
947 /* EXIT_IGNORE_STACK should be nonzero if, when returning from a function,
948    the stack pointer does not matter.  The value is tested only in
949    functions that have frame pointers.
950    No definition is equivalent to always zero.  */
951 
952 #define EXIT_IGNORE_STACK 1
953 
954 /* Define registers used by the epilogue and return instruction.  */
955 
956 #define EPILOGUE_USES(REGNO)	((REGNO) == 26)
957 
958 /* Output assembler code for a block containing the constant parts
959    of a trampoline, leaving space for the variable parts.
960 
961    The trampoline should set the static chain pointer to value placed
962    into the trampoline and should branch to the specified routine.
963    Note that $27 has been set to the address of the trampoline, so we can
964    use it for addressability of the two data items.  */
965 
966 #define TRAMPOLINE_TEMPLATE(FILE)		\
967 do {						\
968   fprintf (FILE, "\tldq $1,24($27)\n");		\
969   fprintf (FILE, "\tldq $27,16($27)\n");	\
970   fprintf (FILE, "\tjmp $31,($27),0\n");	\
971   fprintf (FILE, "\tnop\n");			\
972   fprintf (FILE, "\t.quad 0,0\n");		\
973 } while (0)
974 
975 /* Section in which to place the trampoline.  On Alpha, instructions
976    may only be placed in a text segment.  */
977 
978 #define TRAMPOLINE_SECTION text_section
979 
980 /* Length in units of the trampoline for entering a nested function.  */
981 
982 #define TRAMPOLINE_SIZE    32
983 
984 /* The alignment of a trampoline, in bits.  */
985 
986 #define TRAMPOLINE_ALIGNMENT  64
987 
988 /* Emit RTL insns to initialize the variable parts of a trampoline.
989    FNADDR is an RTX for the address of the function's pure code.
990    CXT is an RTX for the static chain value for the function.  */
991 
992 #define INITIALIZE_TRAMPOLINE(TRAMP, FNADDR, CXT) \
993   alpha_initialize_trampoline (TRAMP, FNADDR, CXT, 16, 24, 8)
994 
995 /* A C expression whose value is RTL representing the value of the return
996    address for the frame COUNT steps up from the current frame.
997    FRAMEADDR is the frame pointer of the COUNT frame, or the frame pointer of
998    the COUNT-1 frame if RETURN_ADDR_IN_PREVIOUS_FRAME is defined.  */
999 
1000 #define RETURN_ADDR_RTX  alpha_return_addr
1001 
1002 /* Before the prologue, RA lives in $26.  */
1003 #define INCOMING_RETURN_ADDR_RTX  gen_rtx_REG (Pmode, 26)
1004 #define DWARF_FRAME_RETURN_COLUMN DWARF_FRAME_REGNUM (26)
1005 #define DWARF_ALT_FRAME_RETURN_COLUMN DWARF_FRAME_REGNUM (64)
1006 #define DWARF_ZERO_REG 31
1007 
1008 /* Describe how we implement __builtin_eh_return.  */
1009 #define EH_RETURN_DATA_REGNO(N)	((N) < 4 ? (N) + 16 : INVALID_REGNUM)
1010 #define EH_RETURN_STACKADJ_RTX	gen_rtx_REG (Pmode, 28)
1011 #define EH_RETURN_HANDLER_RTX \
1012   gen_rtx_MEM (Pmode, plus_constant (stack_pointer_rtx, \
1013 				     current_function_outgoing_args_size))
1014 
1015 /* Addressing modes, and classification of registers for them.  */
1016 
1017 /* Macros to check register numbers against specific register classes.  */
1018 
1019 /* These assume that REGNO is a hard or pseudo reg number.
1020    They give nonzero only if REGNO is a hard reg of the suitable class
1021    or a pseudo reg currently allocated to a suitable hard reg.
1022    Since they use reg_renumber, they are safe only once reg_renumber
1023    has been allocated, which happens in local-alloc.c.  */
1024 
1025 #define REGNO_OK_FOR_INDEX_P(REGNO) 0
1026 #define REGNO_OK_FOR_BASE_P(REGNO) \
1027 ((REGNO) < 32 || (unsigned) reg_renumber[REGNO] < 32  \
1028  || (REGNO) == 63 || reg_renumber[REGNO] == 63)
1029 
1030 /* Maximum number of registers that can appear in a valid memory address.  */
1031 #define MAX_REGS_PER_ADDRESS 1
1032 
1033 /* Recognize any constant value that is a valid address.  For the Alpha,
1034    there are only constants none since we want to use LDA to load any
1035    symbolic addresses into registers.  */
1036 
1037 #define CONSTANT_ADDRESS_P(X)   \
1038   (GET_CODE (X) == CONST_INT	\
1039    && (unsigned HOST_WIDE_INT) (INTVAL (X) + 0x8000) < 0x10000)
1040 
1041 /* Include all constant integers and constant doubles, but not
1042    floating-point, except for floating-point zero.  */
1043 
1044 #define LEGITIMATE_CONSTANT_P  alpha_legitimate_constant_p
1045 
1046 /* The macros REG_OK_FOR..._P assume that the arg is a REG rtx
1047    and check its validity for a certain class.
1048    We have two alternate definitions for each of them.
1049    The usual definition accepts all pseudo regs; the other rejects
1050    them unless they have been allocated suitable hard regs.
1051    The symbol REG_OK_STRICT causes the latter definition to be used.
1052 
1053    Most source files want to accept pseudo regs in the hope that
1054    they will get allocated to the class that the insn wants them to be in.
1055    Source files for reload pass need to be strict.
1056    After reload, it makes no difference, since pseudo regs have
1057    been eliminated by then.  */
1058 
1059 /* Nonzero if X is a hard reg that can be used as an index
1060    or if it is a pseudo reg.  */
1061 #define REG_OK_FOR_INDEX_P(X) 0
1062 
1063 /* Nonzero if X is a hard reg that can be used as a base reg
1064    or if it is a pseudo reg.  */
1065 #define NONSTRICT_REG_OK_FOR_BASE_P(X)  \
1066   (REGNO (X) < 32 || REGNO (X) == 63 || REGNO (X) >= FIRST_PSEUDO_REGISTER)
1067 
1068 /* ??? Nonzero if X is the frame pointer, or some virtual register
1069    that may eliminate to the frame pointer.  These will be allowed to
1070    have offsets greater than 32K.  This is done because register
1071    elimination offsets will change the hi/lo split, and if we split
1072    before reload, we will require additional instructions.  */
1073 #define NONSTRICT_REG_OK_FP_BASE_P(X)		\
1074   (REGNO (X) == 31 || REGNO (X) == 63		\
1075    || (REGNO (X) >= FIRST_PSEUDO_REGISTER	\
1076        && REGNO (X) < LAST_VIRTUAL_REGISTER))
1077 
1078 /* Nonzero if X is a hard reg that can be used as a base reg.  */
1079 #define STRICT_REG_OK_FOR_BASE_P(X) REGNO_OK_FOR_BASE_P (REGNO (X))
1080 
1081 #ifdef REG_OK_STRICT
1082 #define REG_OK_FOR_BASE_P(X)	STRICT_REG_OK_FOR_BASE_P (X)
1083 #else
1084 #define REG_OK_FOR_BASE_P(X)	NONSTRICT_REG_OK_FOR_BASE_P (X)
1085 #endif
1086 
1087 /* GO_IF_LEGITIMATE_ADDRESS recognizes an RTL expression that is a
1088    valid memory address for an instruction.  */
1089 
1090 #ifdef REG_OK_STRICT
1091 #define GO_IF_LEGITIMATE_ADDRESS(MODE, X, WIN)	\
1092 do {						\
1093   if (alpha_legitimate_address_p (MODE, X, 1))	\
1094     goto WIN;					\
1095 } while (0)
1096 #else
1097 #define GO_IF_LEGITIMATE_ADDRESS(MODE, X, WIN)	\
1098 do {						\
1099   if (alpha_legitimate_address_p (MODE, X, 0))	\
1100     goto WIN;					\
1101 } while (0)
1102 #endif
1103 
1104 /* Try machine-dependent ways of modifying an illegitimate address
1105    to be legitimate.  If we find one, return the new, valid address.
1106    This macro is used in only one place: `memory_address' in explow.c.  */
1107 
1108 #define LEGITIMIZE_ADDRESS(X,OLDX,MODE,WIN)			\
1109 do {								\
1110   rtx new_x = alpha_legitimize_address (X, NULL_RTX, MODE);	\
1111   if (new_x)							\
1112     {								\
1113       X = new_x;						\
1114       goto WIN;							\
1115     }								\
1116 } while (0)
1117 
1118 /* Try a machine-dependent way of reloading an illegitimate address
1119    operand.  If we find one, push the reload and jump to WIN.  This
1120    macro is used in only one place: `find_reloads_address' in reload.c.  */
1121 
1122 #define LEGITIMIZE_RELOAD_ADDRESS(X,MODE,OPNUM,TYPE,IND_L,WIN)		     \
1123 do {									     \
1124   rtx new_x = alpha_legitimize_reload_address (X, MODE, OPNUM, TYPE, IND_L); \
1125   if (new_x)								     \
1126     {									     \
1127       X = new_x;							     \
1128       goto WIN;								     \
1129     }									     \
1130 } while (0)
1131 
1132 /* Go to LABEL if ADDR (a legitimate address expression)
1133    has an effect that depends on the machine mode it is used for.
1134    On the Alpha this is true only for the unaligned modes.   We can
1135    simplify this test since we know that the address must be valid.  */
1136 
1137 #define GO_IF_MODE_DEPENDENT_ADDRESS(ADDR,LABEL)  \
1138 { if (GET_CODE (ADDR) == AND) goto LABEL; }
1139 
1140 /* Specify the machine mode that this machine uses
1141    for the index in the tablejump instruction.  */
1142 #define CASE_VECTOR_MODE SImode
1143 
1144 /* Define as C expression which evaluates to nonzero if the tablejump
1145    instruction expects the table to contain offsets from the address of the
1146    table.
1147 
1148    Do not define this if the table should contain absolute addresses.
1149    On the Alpha, the table is really GP-relative, not relative to the PC
1150    of the table, but we pretend that it is PC-relative; this should be OK,
1151    but we should try to find some better way sometime.  */
1152 #define CASE_VECTOR_PC_RELATIVE 1
1153 
1154 /* Define this as 1 if `char' should by default be signed; else as 0.  */
1155 #define DEFAULT_SIGNED_CHAR 1
1156 
1157 /* Max number of bytes we can move to or from memory
1158    in one reasonably fast instruction.  */
1159 
1160 #define MOVE_MAX 8
1161 
1162 /* If a memory-to-memory move would take MOVE_RATIO or more simple
1163    move-instruction pairs, we will do a movmem or libcall instead.
1164 
1165    Without byte/word accesses, we want no more than four instructions;
1166    with, several single byte accesses are better.  */
1167 
1168 #define MOVE_RATIO  (TARGET_BWX ? 7 : 2)
1169 
1170 /* Largest number of bytes of an object that can be placed in a register.
1171    On the Alpha we have plenty of registers, so use TImode.  */
1172 #define MAX_FIXED_MODE_SIZE	GET_MODE_BITSIZE (TImode)
1173 
1174 /* Nonzero if access to memory by bytes is no faster than for words.
1175    Also nonzero if doing byte operations (specifically shifts) in registers
1176    is undesirable.
1177 
1178    On the Alpha, we want to not use the byte operation and instead use
1179    masking operations to access fields; these will save instructions.  */
1180 
1181 #define SLOW_BYTE_ACCESS	1
1182 
1183 /* Define if operations between registers always perform the operation
1184    on the full register even if a narrower mode is specified.  */
1185 #define WORD_REGISTER_OPERATIONS
1186 
1187 /* Define if loading in MODE, an integral mode narrower than BITS_PER_WORD
1188    will either zero-extend or sign-extend.  The value of this macro should
1189    be the code that says which one of the two operations is implicitly
1190    done, UNKNOWN if none.  */
1191 #define LOAD_EXTEND_OP(MODE) ((MODE) == SImode ? SIGN_EXTEND : ZERO_EXTEND)
1192 
1193 /* Define if loading short immediate values into registers sign extends.  */
1194 #define SHORT_IMMEDIATES_SIGN_EXTEND
1195 
1196 /* Value is 1 if truncating an integer of INPREC bits to OUTPREC bits
1197    is done just by pretending it is already truncated.  */
1198 #define TRULY_NOOP_TRUNCATION(OUTPREC, INPREC) 1
1199 
1200 /* The CIX ctlz and cttz instructions return 64 for zero.  */
1201 #define CLZ_DEFINED_VALUE_AT_ZERO(MODE, VALUE)  ((VALUE) = 64, TARGET_CIX)
1202 #define CTZ_DEFINED_VALUE_AT_ZERO(MODE, VALUE)  ((VALUE) = 64, TARGET_CIX)
1203 
1204 /* Define the value returned by a floating-point comparison instruction.  */
1205 
1206 #define FLOAT_STORE_FLAG_VALUE(MODE) \
1207   REAL_VALUE_ATOF ((TARGET_FLOAT_VAX ? "0.5" : "2.0"), (MODE))
1208 
1209 /* Canonicalize a comparison from one we don't have to one we do have.  */
1210 
1211 #define CANONICALIZE_COMPARISON(CODE,OP0,OP1) \
1212   do {									\
1213     if (((CODE) == GE || (CODE) == GT || (CODE) == GEU || (CODE) == GTU) \
1214 	&& (GET_CODE (OP1) == REG || (OP1) == const0_rtx))		\
1215       {									\
1216 	rtx tem = (OP0);						\
1217 	(OP0) = (OP1);							\
1218 	(OP1) = tem;							\
1219 	(CODE) = swap_condition (CODE);					\
1220       }									\
1221     if (((CODE) == LT || (CODE) == LTU)					\
1222 	&& GET_CODE (OP1) == CONST_INT && INTVAL (OP1) == 256)		\
1223       {									\
1224 	(CODE) = (CODE) == LT ? LE : LEU;				\
1225 	(OP1) = GEN_INT (255);						\
1226       }									\
1227   } while (0)
1228 
1229 /* Specify the machine mode that pointers have.
1230    After generation of rtl, the compiler makes no further distinction
1231    between pointers and any other objects of this machine mode.  */
1232 #define Pmode DImode
1233 
1234 /* Mode of a function address in a call instruction (for indexing purposes).  */
1235 
1236 #define FUNCTION_MODE Pmode
1237 
1238 /* Define this if addresses of constant functions
1239    shouldn't be put through pseudo regs where they can be cse'd.
1240    Desirable on machines where ordinary constants are expensive
1241    but a CALL with constant address is cheap.
1242 
1243    We define this on the Alpha so that gen_call and gen_call_value
1244    get to see the SYMBOL_REF (for the hint field of the jsr).  It will
1245    then copy it into a register, thus actually letting the address be
1246    cse'ed.  */
1247 
1248 #define NO_FUNCTION_CSE
1249 
1250 /* Define this to be nonzero if shift instructions ignore all but the low-order
1251    few bits.  */
1252 #define SHIFT_COUNT_TRUNCATED 1
1253 
1254 /* Control the assembler format that we output.  */
1255 
1256 /* Output to assembler file text saying following lines
1257    may contain character constants, extra white space, comments, etc.  */
1258 #define ASM_APP_ON (TARGET_EXPLICIT_RELOCS ? "\t.set\tmacro\n" : "")
1259 
1260 /* Output to assembler file text saying following lines
1261    no longer contain unusual constructs.  */
1262 #define ASM_APP_OFF (TARGET_EXPLICIT_RELOCS ? "\t.set\tnomacro\n" : "")
1263 
1264 #define TEXT_SECTION_ASM_OP "\t.text"
1265 
1266 /* Output before read-only data.  */
1267 
1268 #define READONLY_DATA_SECTION_ASM_OP "\t.rdata"
1269 
1270 /* Output before writable data.  */
1271 
1272 #define DATA_SECTION_ASM_OP "\t.data"
1273 
1274 /* How to refer to registers in assembler output.
1275    This sequence is indexed by compiler's hard-register-number (see above).  */
1276 
1277 #define REGISTER_NAMES						\
1278 {"$0", "$1", "$2", "$3", "$4", "$5", "$6", "$7", "$8",		\
1279  "$9", "$10", "$11", "$12", "$13", "$14", "$15",		\
1280  "$16", "$17", "$18", "$19", "$20", "$21", "$22", "$23",	\
1281  "$24", "$25", "$26", "$27", "$28", "$29", "$30", "AP",		\
1282  "$f0", "$f1", "$f2", "$f3", "$f4", "$f5", "$f6", "$f7", "$f8",	\
1283  "$f9", "$f10", "$f11", "$f12", "$f13", "$f14", "$f15",		\
1284  "$f16", "$f17", "$f18", "$f19", "$f20", "$f21", "$f22", "$f23",\
1285  "$f24", "$f25", "$f26", "$f27", "$f28", "$f29", "$f30", "FP"}
1286 
1287 /* Strip name encoding when emitting labels.  */
1288 
1289 #define ASM_OUTPUT_LABELREF(STREAM, NAME)	\
1290 do {						\
1291   const char *name_ = NAME;			\
1292   if (*name_ == '@' || *name_ == '%')		\
1293     name_ += 2;					\
1294   if (*name_ == '*')				\
1295     name_++;					\
1296   else						\
1297     fputs (user_label_prefix, STREAM);		\
1298   fputs (name_, STREAM);			\
1299 } while (0)
1300 
1301 /* Globalizing directive for a label.  */
1302 #define GLOBAL_ASM_OP "\t.globl "
1303 
1304 /* The prefix to add to user-visible assembler symbols.  */
1305 
1306 #define USER_LABEL_PREFIX ""
1307 
1308 /* This is how to output a label for a jump table.  Arguments are the same as
1309    for (*targetm.asm_out.internal_label), except the insn for the jump table is
1310    passed.  */
1311 
1312 #define ASM_OUTPUT_CASE_LABEL(FILE,PREFIX,NUM,TABLEINSN)	\
1313 { ASM_OUTPUT_ALIGN (FILE, 2); (*targetm.asm_out.internal_label) (FILE, PREFIX, NUM); }
1314 
1315 /* This is how to store into the string LABEL
1316    the symbol_ref name of an internal numbered label where
1317    PREFIX is the class of label and NUM is the number within the class.
1318    This is suitable for output with `assemble_name'.  */
1319 
1320 #define ASM_GENERATE_INTERNAL_LABEL(LABEL,PREFIX,NUM)	\
1321   sprintf ((LABEL), "*$%s%ld", (PREFIX), (long)(NUM))
1322 
1323 /* We use the default ASCII-output routine, except that we don't write more
1324    than 50 characters since the assembler doesn't support very long lines.  */
1325 
1326 #define ASM_OUTPUT_ASCII(MYFILE, MYSTRING, MYLENGTH) \
1327   do {									      \
1328     FILE *_hide_asm_out_file = (MYFILE);				      \
1329     const unsigned char *_hide_p = (const unsigned char *) (MYSTRING);	      \
1330     int _hide_thissize = (MYLENGTH);					      \
1331     int _size_so_far = 0;						      \
1332     {									      \
1333       FILE *asm_out_file = _hide_asm_out_file;				      \
1334       const unsigned char *p = _hide_p;					      \
1335       int thissize = _hide_thissize;					      \
1336       int i;								      \
1337       fprintf (asm_out_file, "\t.ascii \"");				      \
1338 									      \
1339       for (i = 0; i < thissize; i++)					      \
1340 	{								      \
1341 	  register int c = p[i];					      \
1342 									      \
1343 	  if (_size_so_far ++ > 50 && i < thissize - 4)			      \
1344 	    _size_so_far = 0, fprintf (asm_out_file, "\"\n\t.ascii \"");      \
1345 									      \
1346 	  if (c == '\"' || c == '\\')					      \
1347 	    putc ('\\', asm_out_file);					      \
1348 	  if (c >= ' ' && c < 0177)					      \
1349 	    putc (c, asm_out_file);					      \
1350 	  else								      \
1351 	    {								      \
1352 	      fprintf (asm_out_file, "\\%o", c);			      \
1353 	      /* After an octal-escape, if a digit follows,		      \
1354 		 terminate one string constant and start another.	      \
1355 		 The VAX assembler fails to stop reading the escape	      \
1356 		 after three digits, so this is the only way we		      \
1357 		 can get it to parse the data properly.  */		      \
1358 	      if (i < thissize - 1 && ISDIGIT (p[i + 1]))		      \
1359 		_size_so_far = 0, fprintf (asm_out_file, "\"\n\t.ascii \"");  \
1360 	  }								      \
1361 	}								      \
1362       fprintf (asm_out_file, "\"\n");					      \
1363     }									      \
1364   }									      \
1365   while (0)
1366 
1367 /* This is how to output an element of a case-vector that is relative.  */
1368 
1369 #define ASM_OUTPUT_ADDR_DIFF_ELT(FILE, BODY, VALUE, REL) \
1370   fprintf (FILE, "\t.%s $L%d\n", TARGET_ABI_WINDOWS_NT ? "long" : "gprel32", \
1371 	   (VALUE))
1372 
1373 /* This is how to output an assembler line
1374    that says to advance the location counter
1375    to a multiple of 2**LOG bytes.  */
1376 
1377 #define ASM_OUTPUT_ALIGN(FILE,LOG)	\
1378   if ((LOG) != 0)			\
1379     fprintf (FILE, "\t.align %d\n", LOG);
1380 
1381 /* This is how to advance the location counter by SIZE bytes.  */
1382 
1383 #define ASM_OUTPUT_SKIP(FILE,SIZE)  \
1384   fprintf (FILE, "\t.space "HOST_WIDE_INT_PRINT_UNSIGNED"\n", (SIZE))
1385 
1386 /* This says how to output an assembler line
1387    to define a global common symbol.  */
1388 
1389 #define ASM_OUTPUT_COMMON(FILE, NAME, SIZE, ROUNDED)  \
1390 ( fputs ("\t.comm ", (FILE)),			\
1391   assemble_name ((FILE), (NAME)),		\
1392   fprintf ((FILE), ","HOST_WIDE_INT_PRINT_UNSIGNED"\n", (SIZE)))
1393 
1394 /* This says how to output an assembler line
1395    to define a local common symbol.  */
1396 
1397 #define ASM_OUTPUT_LOCAL(FILE, NAME, SIZE,ROUNDED)	\
1398 ( fputs ("\t.lcomm ", (FILE)),				\
1399   assemble_name ((FILE), (NAME)),			\
1400   fprintf ((FILE), ","HOST_WIDE_INT_PRINT_UNSIGNED"\n", (SIZE)))
1401 
1402 
1403 /* Print operand X (an rtx) in assembler syntax to file FILE.
1404    CODE is a letter or dot (`z' in `%z0') or 0 if no letter was specified.
1405    For `%' followed by punctuation, CODE is the punctuation and X is null.  */
1406 
1407 #define PRINT_OPERAND(FILE, X, CODE)  print_operand (FILE, X, CODE)
1408 
1409 /* Determine which codes are valid without a following integer.  These must
1410    not be alphabetic.
1411 
1412    ~    Generates the name of the current function.
1413 
1414    /	Generates the instruction suffix.  The TRAP_SUFFIX and ROUND_SUFFIX
1415 	attributes are examined to determine what is appropriate.
1416 
1417    ,    Generates single precision suffix for floating point
1418 	instructions (s for IEEE, f for VAX)
1419 
1420    -	Generates double precision suffix for floating point
1421 	instructions (t for IEEE, g for VAX)
1422 
1423    +	Generates a nop instruction after a noreturn call at the very end
1424 	of the function
1425    */
1426 
1427 #define PRINT_OPERAND_PUNCT_VALID_P(CODE) \
1428   ((CODE) == '/' || (CODE) == ',' || (CODE) == '-' || (CODE) == '~' \
1429    || (CODE) == '#' || (CODE) == '*' || (CODE) == '&' || (CODE) == '+')
1430 
1431 /* Print a memory address as an operand to reference that memory location.  */
1432 
1433 #define PRINT_OPERAND_ADDRESS(FILE, ADDR) \
1434   print_operand_address((FILE), (ADDR))
1435 
1436 /* Implement `va_start' for varargs and stdarg.  */
1437 #define EXPAND_BUILTIN_VA_START(valist, nextarg) \
1438   alpha_va_start (valist, nextarg)
1439 
1440 /* Tell collect that the object format is ECOFF.  */
1441 #define OBJECT_FORMAT_COFF
1442 #define EXTENDED_COFF
1443 
1444 /* If we use NM, pass -g to it so it only lists globals.  */
1445 #define NM_FLAGS "-pg"
1446 
1447 /* Definitions for debugging.  */
1448 
1449 #define SDB_DEBUGGING_INFO 1		/* generate info for mips-tfile */
1450 #define DBX_DEBUGGING_INFO 1		/* generate embedded stabs */
1451 #define MIPS_DEBUGGING_INFO 1		/* MIPS specific debugging info */
1452 
1453 #ifndef PREFERRED_DEBUGGING_TYPE	/* assume SDB_DEBUGGING_INFO */
1454 #define PREFERRED_DEBUGGING_TYPE  SDB_DEBUG
1455 #endif
1456 
1457 
1458 /* Correct the offset of automatic variables and arguments.  Note that
1459    the Alpha debug format wants all automatic variables and arguments
1460    to be in terms of two different offsets from the virtual frame pointer,
1461    which is the stack pointer before any adjustment in the function.
1462    The offset for the argument pointer is fixed for the native compiler,
1463    it is either zero (for the no arguments case) or large enough to hold
1464    all argument registers.
1465    The offset for the auto pointer is the fourth argument to the .frame
1466    directive (local_offset).
1467    To stay compatible with the native tools we use the same offsets
1468    from the virtual frame pointer and adjust the debugger arg/auto offsets
1469    accordingly. These debugger offsets are set up in output_prolog.  */
1470 
1471 extern long alpha_arg_offset;
1472 extern long alpha_auto_offset;
1473 #define DEBUGGER_AUTO_OFFSET(X) \
1474   ((GET_CODE (X) == PLUS ? INTVAL (XEXP (X, 1)) : 0) + alpha_auto_offset)
1475 #define DEBUGGER_ARG_OFFSET(OFFSET, X) (OFFSET + alpha_arg_offset)
1476 
1477 /* mips-tfile doesn't understand .stabd directives.  */
1478 #define DBX_OUTPUT_SOURCE_LINE(STREAM, LINE, COUNTER) do {	\
1479   dbxout_begin_stabn_sline (LINE);				\
1480   dbxout_stab_value_internal_label ("LM", &COUNTER);		\
1481 } while (0)
1482 
1483 /* We want to use MIPS-style .loc directives for SDB line numbers.  */
1484 extern int num_source_filenames;
1485 #define SDB_OUTPUT_SOURCE_LINE(STREAM, LINE)	\
1486   fprintf (STREAM, "\t.loc\t%d %d\n", num_source_filenames, LINE)
1487 
1488 #define ASM_OUTPUT_SOURCE_FILENAME(STREAM, NAME)			\
1489   alpha_output_filename (STREAM, NAME)
1490 
1491 /* mips-tfile.c limits us to strings of one page.  We must underestimate this
1492    number, because the real length runs past this up to the next
1493    continuation point.  This is really a dbxout.c bug.  */
1494 #define DBX_CONTIN_LENGTH 3000
1495 
1496 /* By default, turn on GDB extensions.  */
1497 #define DEFAULT_GDB_EXTENSIONS 1
1498 
1499 /* Stabs-in-ECOFF can't handle dbxout_function_end().  */
1500 #define NO_DBX_FUNCTION_END 1
1501 
1502 /* If we are smuggling stabs through the ALPHA ECOFF object
1503    format, put a comment in front of the .stab<x> operation so
1504    that the ALPHA assembler does not choke.  The mips-tfile program
1505    will correctly put the stab into the object file.  */
1506 
1507 #define ASM_STABS_OP	((TARGET_GAS) ? "\t.stabs\t" : " #.stabs\t")
1508 #define ASM_STABN_OP	((TARGET_GAS) ? "\t.stabn\t" : " #.stabn\t")
1509 #define ASM_STABD_OP	((TARGET_GAS) ? "\t.stabd\t" : " #.stabd\t")
1510 
1511 /* Forward references to tags are allowed.  */
1512 #define SDB_ALLOW_FORWARD_REFERENCES
1513 
1514 /* Unknown tags are also allowed.  */
1515 #define SDB_ALLOW_UNKNOWN_REFERENCES
1516 
1517 #define PUT_SDB_DEF(a)					\
1518 do {							\
1519   fprintf (asm_out_file, "\t%s.def\t",			\
1520 	   (TARGET_GAS) ? "" : "#");			\
1521   ASM_OUTPUT_LABELREF (asm_out_file, a); 		\
1522   fputc (';', asm_out_file);				\
1523 } while (0)
1524 
1525 #define PUT_SDB_PLAIN_DEF(a)				\
1526 do {							\
1527   fprintf (asm_out_file, "\t%s.def\t.%s;",		\
1528 	   (TARGET_GAS) ? "" : "#", (a));		\
1529 } while (0)
1530 
1531 #define PUT_SDB_TYPE(a)					\
1532 do {							\
1533   fprintf (asm_out_file, "\t.type\t0x%x;", (a));	\
1534 } while (0)
1535 
1536 /* For block start and end, we create labels, so that
1537    later we can figure out where the correct offset is.
1538    The normal .ent/.end serve well enough for functions,
1539    so those are just commented out.  */
1540 
1541 extern int sdb_label_count;		/* block start/end next label # */
1542 
1543 #define PUT_SDB_BLOCK_START(LINE)			\
1544 do {							\
1545   fprintf (asm_out_file,				\
1546 	   "$Lb%d:\n\t%s.begin\t$Lb%d\t%d\n",		\
1547 	   sdb_label_count,				\
1548 	   (TARGET_GAS) ? "" : "#",			\
1549 	   sdb_label_count,				\
1550 	   (LINE));					\
1551   sdb_label_count++;					\
1552 } while (0)
1553 
1554 #define PUT_SDB_BLOCK_END(LINE)				\
1555 do {							\
1556   fprintf (asm_out_file,				\
1557 	   "$Le%d:\n\t%s.bend\t$Le%d\t%d\n",		\
1558 	   sdb_label_count,				\
1559 	   (TARGET_GAS) ? "" : "#",			\
1560 	   sdb_label_count,				\
1561 	   (LINE));					\
1562   sdb_label_count++;					\
1563 } while (0)
1564 
1565 #define PUT_SDB_FUNCTION_START(LINE)
1566 
1567 #define PUT_SDB_FUNCTION_END(LINE)
1568 
1569 #define PUT_SDB_EPILOGUE_END(NAME) ((void)(NAME))
1570 
1571 /* Macros for mips-tfile.c to encapsulate stabs in ECOFF, and for
1572    mips-tdump.c to print them out.
1573 
1574    These must match the corresponding definitions in gdb/mipsread.c.
1575    Unfortunately, gcc and gdb do not currently share any directories.  */
1576 
1577 #define CODE_MASK 0x8F300
1578 #define MIPS_IS_STAB(sym) (((sym)->index & 0xFFF00) == CODE_MASK)
1579 #define MIPS_MARK_STAB(code) ((code)+CODE_MASK)
1580 #define MIPS_UNMARK_STAB(code) ((code)-CODE_MASK)
1581 
1582 /* Override some mips-tfile definitions.  */
1583 
1584 #define SHASH_SIZE 511
1585 #define THASH_SIZE 55
1586 
1587 /* Align ecoff symbol tables to avoid OSF1/1.3 nm complaints.  */
1588 
1589 #define ALIGN_SYMTABLE_OFFSET(OFFSET) (((OFFSET) + 7) & ~7)
1590 
1591 /* The system headers under Alpha systems are generally C++-aware.  */
1592 #define NO_IMPLICIT_EXTERN_C
1593