1/* Definitions of target machine for GNU compiler, for MMIX.
2   Copyright (C) 2000, 2001, 2002, 2004, 2005, 2007, 2008, 2009
3   Free Software Foundation, Inc.
4   Contributed by Hans-Peter Nilsson (hp@bitrange.com)
5
6This file is part of GCC.
7
8GCC is free software; you can redistribute it and/or modify
9it under the terms of the GNU General Public License as published by
10the Free Software Foundation; either version 3, or (at your option)
11any later version.
12
13GCC is distributed in the hope that it will be useful,
14but WITHOUT ANY WARRANTY; without even the implied warranty of
15MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
16GNU General Public License for more details.
17
18You should have received a copy of the GNU General Public License
19along with GCC; see the file COPYING3.  If not see
20<http://www.gnu.org/licenses/>.  */
21
22#ifndef GCC_MMIX_H
23#define GCC_MMIX_H
24
25/* First, some local helper macros.  Note that the "default" value of
26   FIXED_REGISTERS, CALL_USED_REGISTERS, REG_ALLOC_ORDER and
27   REG_CLASS_CONTENTS depend on these values.  */
28#define MMIX_RESERVED_GNU_ARG_0_REGNUM 231
29#define MMIX_FIRST_ARG_REGNUM \
30  (TARGET_ABI_GNU ? MMIX_RESERVED_GNU_ARG_0_REGNUM : 16)
31#define MMIX_FIRST_INCOMING_ARG_REGNUM \
32  (TARGET_ABI_GNU ? MMIX_RESERVED_GNU_ARG_0_REGNUM : 0)
33#define MMIX_MAX_ARGS_IN_REGS 16
34
35/* FIXME: This one isn't fully implemented yet.  Return values larger than
36   one register are passed by reference in MMIX_STRUCT_VALUE_REGNUM by the
37   caller, except for return values of type "complex".  */
38#define MMIX_MAX_REGS_FOR_VALUE 16
39#define MMIX_RETURN_VALUE_REGNUM \
40  (TARGET_ABI_GNU ? MMIX_RESERVED_GNU_ARG_0_REGNUM : 15)
41#define MMIX_OUTGOING_RETURN_VALUE_REGNUM \
42  (TARGET_ABI_GNU ? MMIX_RESERVED_GNU_ARG_0_REGNUM : 0)
43#define MMIX_STRUCT_VALUE_REGNUM 251
44#define MMIX_STATIC_CHAIN_REGNUM 252
45#define MMIX_FRAME_POINTER_REGNUM 253
46#define MMIX_STACK_POINTER_REGNUM 254
47#define MMIX_LAST_GENERAL_REGISTER 255
48#define MMIX_INCOMING_RETURN_ADDRESS_REGNUM MMIX_rJ_REGNUM
49#define MMIX_HIMULT_REGNUM 258
50#define MMIX_REMAINDER_REGNUM MMIX_rR_REGNUM
51#define MMIX_ARG_POINTER_REGNUM 261
52#define MMIX_rO_REGNUM 262
53#define MMIX_LAST_STACK_REGISTER_REGNUM 31
54
55/* Four registers; "ideally, these registers should be call-clobbered", so
56   just grab a bunch of the common clobbered registers.  FIXME: Last
57   registers of return-value should be used, with an error if there's a
58   return-value (that collides in size).  */
59#define MMIX_EH_RETURN_DATA_REGNO_START (MMIX_STRUCT_VALUE_REGNUM - 4)
60
61/* Try to keep the definitions from running away on their own.  */
62#if (MMIX_EH_RETURN_DATA_REGNO_START \
63     != MMIX_RESERVED_GNU_ARG_0_REGNUM + MMIX_MAX_ARGS_IN_REGS)
64 #error MMIX register definition inconsistency
65#endif
66
67#if (MMIX_MAX_REGS_FOR_VALUE + MMIX_MAX_ARGS_IN_REGS > 32)
68 #error MMIX parameters and return values bad, more than 32 registers
69#endif
70
71/* This chosen as "a call-clobbered hard register that is otherwise
72   untouched by the epilogue".  */
73#define MMIX_EH_RETURN_STACKADJ_REGNUM MMIX_STATIC_CHAIN_REGNUM
74
75#ifdef REG_OK_STRICT
76# define MMIX_REG_OK_STRICT 1
77#else
78# define MMIX_REG_OK_STRICT 0
79#endif
80
81#define MMIX_FUNCTION_ARG_SIZE(MODE, TYPE) \
82 ((MODE) != BLKmode ? GET_MODE_SIZE (MODE) : int_size_in_bytes (TYPE))
83
84/* Per-function machine data.  This is normally an opaque type just
85   defined and used in the tm.c file, but we need to see the definition in
86   mmix.md too.  */
87struct GTY(()) machine_function
88 {
89   int has_landing_pad;
90   int highest_saved_stack_register;
91   int in_prologue;
92 };
93
94/* For these target macros, there is no generic documentation here.  You
95   should read `Using and Porting GCC' for that.  Only comments specific
96   to the MMIX target are here.
97
98   There are however references to the specific texinfo node (comments
99   with "Node:"), so there should be little or nothing amiss.  Probably
100   the opposite, since we don't have to care about old littering and
101   soon outdated generic comments.  */
102
103/* Node: Driver */
104
105/* User symbols are in the same name-space as built-in symbols, but we
106   don't need the built-in symbols, so remove those and instead apply
107   stricter operand checking.  Don't warn when expanding insns.  */
108#define ASM_SPEC "-no-predefined-syms -x"
109
110/* Pass on -mset-program-start=N and -mset-data-start=M to the linker.
111   Provide default program start 0x100 unless -mno-set-program-start.
112   Don't do this if linking relocatably, with -r.  For a final link,
113   produce mmo, unless ELF is requested or when linking relocatably.  */
114#define LINK_SPEC \
115 "%{mset-program-start=*:--defsym __.MMIX.start..text=%*}\
116  %{mset-data-start=*:--defsym __.MMIX.start..data=%*}\
117  %{!mset-program-start=*:\
118    %{!mno-set-program-start:\
119     %{!r:--defsym __.MMIX.start..text=0x100}}}\
120  %{!melf:%{!r:-m mmo}}%{melf|r:-m elf64mmix}"
121
122/* FIXME: There's no provision for profiling here.  */
123#define STARTFILE_SPEC  \
124  "crti%O%s crtbegin%O%s"
125
126#define ENDFILE_SPEC "crtend%O%s crtn%O%s"
127
128/* Node: Run-time Target */
129
130/* Define __LONG_MAX__, since we're advised not to change glimits.h.  */
131#define TARGET_CPU_CPP_BUILTINS()				\
132  do								\
133    {								\
134      builtin_define ("__mmix__");				\
135      builtin_define ("__MMIX__");				\
136      if (TARGET_ABI_GNU)					\
137	builtin_define ("__MMIX_ABI_GNU__");			\
138      else							\
139	builtin_define ("__MMIX_ABI_MMIXWARE__");		\
140    }								\
141  while (0)
142
143extern int target_flags;
144
145#define TARGET_DEFAULT \
146 (MASK_BRANCH_PREDICT | MASK_BASE_ADDRESSES | MASK_USE_RETURN_INSN)
147
148/* Unfortunately, this must not reference anything in "mmix.c".  */
149#define TARGET_VERSION \
150  fprintf (stderr, " (MMIX)")
151
152#define OVERRIDE_OPTIONS mmix_override_options ()
153
154#define OPTIMIZATION_OPTIONS(LEVEL, SIZE)	\
155  do						\
156    {						\
157      if (LEVEL >= 1)				\
158	flag_regmove = TRUE;			\
159      						\
160      if (SIZE || LEVEL > 1)			\
161	{					\
162	  flag_omit_frame_pointer = TRUE;	\
163	}					\
164    }						\
165  while (0)
166
167/* This one will have to wait a little bit; right now we can't debug
168   neither with or without a frame-pointer.  */
169/* #define CAN_DEBUG_WITHOUT_FP */
170
171
172/* Node: Per-Function Data */
173#define INIT_EXPANDERS mmix_init_expanders ()
174
175
176/* Node: Storage Layout */
177/* I see no bit-field instructions.  Anyway, the common order is from low
178   to high, as the power of two, hence little-endian.  */
179#define BITS_BIG_ENDIAN 0
180#define BYTES_BIG_ENDIAN 1
181#define WORDS_BIG_ENDIAN 1
182#define FLOAT_WORDS_BIG_ENDIAN 1
183#define UNITS_PER_WORD 8
184
185/* We need to align everything to 64 bits that can affect the alignment
186   of other types.  Since address N is interpreted in MMIX as (N modulo
187   access_size), we must align.  */
188#define PARM_BOUNDARY 64
189#define STACK_BOUNDARY 64
190#define FUNCTION_BOUNDARY 32
191#define BIGGEST_ALIGNMENT 64
192
193/* This one is only used in the ADA front end.  */
194#define MINIMUM_ATOMIC_ALIGNMENT 8
195
196/* Copied from elfos.h.  */
197#define MAX_OFILE_ALIGNMENT (32768 * 8)
198
199#define DATA_ALIGNMENT(TYPE, BASIC_ALIGN) \
200 mmix_data_alignment (TYPE, BASIC_ALIGN)
201
202#define CONSTANT_ALIGNMENT(CONSTANT, BASIC_ALIGN) \
203 mmix_constant_alignment (CONSTANT, BASIC_ALIGN)
204
205#define LOCAL_ALIGNMENT(TYPE, BASIC_ALIGN) \
206 mmix_local_alignment (TYPE, BASIC_ALIGN)
207
208/* Following other ports, this seems to most commonly be the word-size,
209   so let's do that here too.  */
210#define EMPTY_FIELD_BOUNDARY 64
211
212/* We chose to have this low solely for similarity with the alpha.  It has
213   nothing to do with passing the tests dg/c99-scope-2 and
214   execute/align-1.c.  Nothing.  Though the tests seem wrong.  Padding of
215   the structure is automatically added to get alignment when needed if we
216   set this to just byte-boundary.  */
217#define STRUCTURE_SIZE_BOUNDARY 8
218
219/* The lower bits are ignored.  */
220#define STRICT_ALIGNMENT 1
221
222
223/* Node: Type Layout */
224
225/* It might seem more natural to have 64-bit ints on a 64-bit machine,
226   but then an occasional MMIX programmer needs to know how to put a lot
227   of __attribute__ stuff to get to the 8, 16 and 32-bit modes rather
228   than the "intuitive" char, short and int types.  */
229#define INT_TYPE_SIZE 32
230#define SHORT_TYPE_SIZE 16
231#define LONG_LONG_TYPE_SIZE 64
232
233#define FLOAT_TYPE_SIZE 32
234#define DOUBLE_TYPE_SIZE 64
235#define LONG_DOUBLE_TYPE_SIZE 64
236
237#define DEFAULT_SIGNED_CHAR 1
238
239
240/* Node: Register Basics */
241/* We tell GCC about all 256 general registers, and we also include
242   rD, rE, rH, rJ, rR and rO (in that order) so we can describe what insns
243   clobber them.  We use a faked register for the argument pointer.  It is
244   always eliminated towards the frame-pointer or the stack-pointer, never
245   output in assembly.  Any fixed register would do for this, like $255,
246   but future debugging is easier when using a separate register.  It
247   counts as a global register for pseudorandom reasons.  */
248#define FIRST_PSEUDO_REGISTER 263
249
250/* We treat general registers with no assigned purpose as fixed.  The
251   stack pointer, $254, is also fixed.  Register $255 is referred to as a
252   temporary register in the MMIX papers, and used as such in mmixal, so
253   it should not be used as a stack pointer.  We set it to fixed, and use
254   it "manually" at times of despair.  */
255#define FIXED_REGISTERS \
256 { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, \
257   0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, \
258   1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, \
259   1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, \
260   1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, \
261   1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, \
262   1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, \
263   1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, \
264   1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, \
265   1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, \
266   1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, \
267   1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, \
268   1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, \
269   1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, \
270   1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, \
271   1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0, 1, 1, \
272   1, 1, 0, 0, 0, 1, 1 \
273 }
274
275/* General registers are fixed and therefore "historically" marked
276   call-used.  (FIXME: This has changed).  Registers $15..$31 are
277   call-clobbered; we'll put arguments in $16 and up, and we need $15 for
278   the MMIX register-stack "hole".  */
279#define CALL_USED_REGISTERS \
280 { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, \
281   1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, \
282   1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, \
283   1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, \
284   1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, \
285   1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, \
286   1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, \
287   1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, \
288   1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, \
289   1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, \
290   1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, \
291   1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, \
292   1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, \
293   1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, \
294   1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, \
295   1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 1, 1, \
296   1, 1, 1, 1, 1, 1, 1 \
297 }
298
299#define CONDITIONAL_REGISTER_USAGE mmix_conditional_register_usage ()
300
301#define INCOMING_REGNO(OUT) mmix_opposite_regno (OUT, 0)
302
303#define OUTGOING_REGNO(IN) mmix_opposite_regno (IN, 1)
304
305/* Defining LOCAL_REGNO is necessary in presence of prologue/epilogue,
306   else GCC will be confused that those registers aren't saved and
307   restored.  */
308#define LOCAL_REGNO(REGNO) mmix_local_regno (REGNO)
309
310/* Node: Allocation Order */
311
312/* We should allocate registers from 0 to 31 by increasing number, because
313   I think that's what people expect.  Beyond that, just use
314   call-clobbered global registers first, then call-clobbered special
315   registers.  Last, the fixed registers.  */
316#define MMIX_MMIXWARE_ABI_REG_ALLOC_ORDER	\
317 { 0, 1, 2, 3, 4, 5, 6, 7,			\
318   8, 9, 10, 11, 12, 13, 14, 15,		\
319   16, 17, 18, 19, 20, 21, 22, 23,		\
320   24, 25, 26, 27, 28, 29, 30, 31,    		\
321						\
322   252, 251, 250, 249, 248, 247, 		\
323						\
324   253,						\
325						\
326   258, 260, 259,				\
327						\
328   32, 33, 34, 35, 36, 37, 38, 39,		\
329   40, 41, 42, 43, 44, 45, 46, 47,		\
330   48, 49, 50, 51, 52, 53, 54, 55,		\
331   56, 57, 58, 59, 60, 61, 62, 63,		\
332   64, 65, 66, 67, 68, 69, 70, 71,		\
333   72, 73, 74, 75, 76, 77, 78, 79,		\
334   80, 81, 82, 83, 84, 85, 86, 87,		\
335   88, 89, 90, 91, 92, 93, 94, 95,		\
336   96, 97, 98, 99, 100, 101, 102, 103,		\
337   104, 105, 106, 107, 108, 109, 110, 111,	\
338   112, 113, 114, 115, 116, 117, 118, 119,	\
339   120, 121, 122, 123, 124, 125, 126, 127,	\
340   128, 129, 130, 131, 132, 133, 134, 135,	\
341   136, 137, 138, 139, 140, 141, 142, 143,	\
342   144, 145, 146, 147, 148, 149, 150, 151,	\
343   152, 153, 154, 155, 156, 157, 158, 159,	\
344   160, 161, 162, 163, 164, 165, 166, 167,	\
345   168, 169, 170, 171, 172, 173, 174, 175,	\
346   176, 177, 178, 179, 180, 181, 182, 183,	\
347   184, 185, 186, 187, 188, 189, 190, 191,	\
348   192, 193, 194, 195, 196, 197, 198, 199,	\
349   200, 201, 202, 203, 204, 205, 206, 207,	\
350   208, 209, 210, 211, 212, 213, 214, 215,	\
351   216, 217, 218, 219, 220, 221, 222, 223,	\
352   224, 225, 226, 227, 228, 229, 230, 231,	\
353   232, 233, 234, 235, 236, 237, 238, 239,	\
354   240, 241, 242, 243, 244, 245, 246,		\
355						\
356   254, 255, 256, 257, 261, 262			\
357 }
358
359/* As a convenience, we put this nearby, for ease of comparison.
360   First, call-clobbered registers in reverse order of assignment as
361   parameters (also the top ones; not because they're parameters, but
362   for continuity).
363
364   Second, saved registers that go on the register-stack.
365
366   Third, special registers rH, rR and rJ.  They should not normally be
367   allocated, but since they're call-clobbered, it is cheaper to use one
368   of them than using a call-saved register for a call-clobbered use,
369   assuming it is referenced a very limited number of times.  Other global
370   and fixed registers come next; they are never allocated.  */
371#define MMIX_GNU_ABI_REG_ALLOC_ORDER		\
372 { 252, 251, 250, 249, 248, 247, 246,		\
373   245, 244, 243, 242, 241, 240, 239, 238,	\
374   237, 236, 235, 234, 233, 232, 231,		\
375						\
376   0, 1, 2, 3, 4, 5, 6, 7,			\
377   8, 9, 10, 11, 12, 13, 14, 15,		\
378   16, 17, 18, 19, 20, 21, 22, 23,		\
379   24, 25, 26, 27, 28, 29, 30, 31,		\
380						\
381   253,						\
382						\
383   258, 260, 259,				\
384						\
385   32, 33, 34, 35, 36, 37, 38, 39,		\
386   40, 41, 42, 43, 44, 45, 46, 47,		\
387   48, 49, 50, 51, 52, 53, 54, 55,		\
388   56, 57, 58, 59, 60, 61, 62, 63,		\
389   64, 65, 66, 67, 68, 69, 70, 71,		\
390   72, 73, 74, 75, 76, 77, 78, 79,		\
391   80, 81, 82, 83, 84, 85, 86, 87,		\
392   88, 89, 90, 91, 92, 93, 94, 95,		\
393   96, 97, 98, 99, 100, 101, 102, 103,		\
394   104, 105, 106, 107, 108, 109, 110, 111,	\
395   112, 113, 114, 115, 116, 117, 118, 119,	\
396   120, 121, 122, 123, 124, 125, 126, 127,	\
397   128, 129, 130, 131, 132, 133, 134, 135,	\
398   136, 137, 138, 139, 140, 141, 142, 143,	\
399   144, 145, 146, 147, 148, 149, 150, 151,	\
400   152, 153, 154, 155, 156, 157, 158, 159,	\
401   160, 161, 162, 163, 164, 165, 166, 167,	\
402   168, 169, 170, 171, 172, 173, 174, 175,	\
403   176, 177, 178, 179, 180, 181, 182, 183,	\
404   184, 185, 186, 187, 188, 189, 190, 191,	\
405   192, 193, 194, 195, 196, 197, 198, 199,	\
406   200, 201, 202, 203, 204, 205, 206, 207,	\
407   208, 209, 210, 211, 212, 213, 214, 215,	\
408   216, 217, 218, 219, 220, 221, 222, 223,	\
409   224, 225, 226, 227, 228, 229, 230,		\
410						\
411   254, 255, 256, 257, 261, 262			\
412 }
413
414/* The default one.  */
415#define REG_ALLOC_ORDER MMIX_MMIXWARE_ABI_REG_ALLOC_ORDER
416
417/* Node: Values in Registers */
418
419#define HARD_REGNO_NREGS(REGNO, MODE)            	\
420   ((GET_MODE_SIZE (MODE) + UNITS_PER_WORD - 1)  	\
421    / UNITS_PER_WORD)
422
423#define HARD_REGNO_MODE_OK(REGNO, MODE) 1
424
425/* Note that no register can really be accessed in single-float mode, so
426   we *can* say 1 here.  FIXME:  Will TRT happen for single-float, or do
427   we have to punt to libgcc1.asm?  */
428#define MODES_TIEABLE_P(MODE1, MODE2) 1
429
430
431/* Node: Leaf Functions */
432/* (empty) */
433
434
435/* Node: Register Classes */
436
437enum reg_class
438 {
439   NO_REGS, GENERAL_REGS, REMAINDER_REG, HIMULT_REG,
440   SYSTEM_REGS, ALL_REGS, LIM_REG_CLASSES
441 };
442
443#define N_REG_CLASSES (int) LIM_REG_CLASSES
444
445#define REG_CLASS_NAMES						\
446 {"NO_REGS", "GENERAL_REGS", "REMAINDER_REG", "HIMULT_REG",	\
447  "SYSTEM_REGS", "ALL_REGS"}
448
449/* Note that the contents of each item is always 32 bits.  */
450#define REG_CLASS_CONTENTS			\
451 {{0, 0, 0, 0, 0, 0, 0, 0, 0},			\
452  {~0, ~0, ~0, ~0, ~0, ~0, ~0, ~0, 0x20},	\
453  {0, 0, 0, 0, 0, 0, 0, 0, 0x10},		\
454  {0, 0, 0, 0, 0, 0, 0, 0, 4},			\
455  {0, 0, 0, 0, 0, 0, 0, 0, 0x7f},		\
456  {~0, ~0, ~0, ~0, ~0, ~0, ~0, ~0, 0x7f}}
457
458#define REGNO_REG_CLASS(REGNO)					\
459 ((REGNO) <= MMIX_LAST_GENERAL_REGISTER				\
460  || (REGNO) == MMIX_ARG_POINTER_REGNUM				\
461  ? GENERAL_REGS						\
462  : (REGNO) == MMIX_REMAINDER_REGNUM ? REMAINDER_REG		\
463  : (REGNO) == MMIX_HIMULT_REGNUM ? HIMULT_REG : SYSTEM_REGS)
464
465#define BASE_REG_CLASS GENERAL_REGS
466
467#define INDEX_REG_CLASS GENERAL_REGS
468
469#define REG_CLASS_FROM_LETTER(CHAR)		\
470 ((CHAR) == 'x' ? SYSTEM_REGS			\
471  : (CHAR) == 'y' ? REMAINDER_REG		\
472  : (CHAR) == 'z' ? HIMULT_REG : NO_REGS)
473
474#define REGNO_OK_FOR_BASE_P(REGNO)				\
475 ((REGNO) <= MMIX_LAST_GENERAL_REGISTER				\
476  || (REGNO) == MMIX_ARG_POINTER_REGNUM				\
477  || (reg_renumber[REGNO] > 0					\
478      && reg_renumber[REGNO] <= MMIX_LAST_GENERAL_REGISTER))
479
480#define REGNO_OK_FOR_INDEX_P(REGNO) REGNO_OK_FOR_BASE_P (REGNO)
481
482#define PREFERRED_RELOAD_CLASS(X, CLASS) \
483 mmix_preferred_reload_class (X, CLASS)
484
485#define PREFERRED_OUTPUT_RELOAD_CLASS(X, CLASS) \
486 mmix_preferred_output_reload_class (X, CLASS)
487
488#define SECONDARY_INPUT_RELOAD_CLASS(CLASS, MODE, X) \
489 mmix_secondary_reload_class (CLASS, MODE, X, 1)
490
491#define SECONDARY_OUTPUT_RELOAD_CLASS(CLASS, MODE, X) \
492 mmix_secondary_reload_class (CLASS, MODE, X, 0)
493
494#define CLASS_MAX_NREGS(CLASS, MODE) HARD_REGNO_NREGS (CLASS, MODE)
495
496#define CONST_OK_FOR_LETTER_P(VALUE, C)	\
497 mmix_const_ok_for_letter_p (VALUE, C)
498
499#define EXTRA_CONSTRAINT(VALUE, C)	\
500 mmix_extra_constraint (VALUE, C, MMIX_REG_OK_STRICT)
501
502/* Do we need anything serious here?  Yes, any FLOT constant.  */
503#define CONST_DOUBLE_OK_FOR_LETTER_P(VALUE, C)			\
504 mmix_const_double_ok_for_letter_p (VALUE, C)
505
506
507/* Node: Frame Layout */
508
509#define STACK_GROWS_DOWNWARD
510#define FRAME_GROWS_DOWNWARD 1
511
512#define STARTING_FRAME_OFFSET \
513  mmix_starting_frame_offset ()
514
515#define FIRST_PARM_OFFSET(FUNDECL) 0
516
517#define DYNAMIC_CHAIN_ADDRESS(FRAMEADDR) \
518 mmix_dynamic_chain_address (FRAMEADDR)
519
520/* FIXME: It seems RETURN_ADDR_OFFSET is undocumented.  */
521
522#define SETUP_FRAME_ADDRESSES() \
523 mmix_setup_frame_addresses ()
524
525#define RETURN_ADDR_RTX(COUNT, FRAME)		\
526 mmix_return_addr_rtx (COUNT, FRAME)
527
528/* It's in rJ before we store it somewhere.  */
529#define INCOMING_RETURN_ADDR_RTX \
530 gen_rtx_REG (Pmode, MMIX_INCOMING_RETURN_ADDRESS_REGNUM)
531
532/* FIXME: This does not seem properly documented or cross-indexed.
533   Nowhere except in the code does it say it *has* to be in the range
534   0..255, or else it will be truncated.  That goes for the default too.  */
535#define DWARF_FRAME_RETURN_COLUMN \
536 DWARF_FRAME_REGNUM (MMIX_INCOMING_RETURN_ADDRESS_REGNUM)
537
538/* No return address is stored there.  */
539#define INCOMING_FRAME_SP_OFFSET 0
540
541/* Node: Stack Checking */
542/* (empty) */
543
544
545/* Node: Exception Handling */
546
547#define EH_RETURN_DATA_REGNO(N) \
548 mmix_eh_return_data_regno (N)
549
550#define EH_RETURN_STACKADJ_RTX \
551 mmix_eh_return_stackadj_rtx ()
552
553#define EH_RETURN_HANDLER_RTX \
554 mmix_eh_return_handler_rtx ()
555
556#define ASM_PREFERRED_EH_DATA_FORMAT(CODE, GLOBAL) \
557 mmix_asm_preferred_eh_data_format (CODE, GLOBAL)
558
559/* Node: Frame Registers */
560#define STACK_POINTER_REGNUM MMIX_STACK_POINTER_REGNUM
561
562/* Perhaps we can use HARD_FRAME_POINTER_REGNUM and decide later on
563   what register we want to use.  */
564#define FRAME_POINTER_REGNUM MMIX_FRAME_POINTER_REGNUM
565#define ARG_POINTER_REGNUM MMIX_ARG_POINTER_REGNUM
566
567#define STATIC_CHAIN_REGNUM MMIX_STATIC_CHAIN_REGNUM
568
569
570/* Node: Elimination */
571
572/* The frame-pointer is stored in a location that either counts to the
573   offset of incoming parameters, or that counts to the offset of the
574   frame, so we can't use a single offset.  We therefore eliminate those
575   two separately.  */
576#define ELIMINABLE_REGS				\
577 {{ARG_POINTER_REGNUM, STACK_POINTER_REGNUM},	\
578  {ARG_POINTER_REGNUM, FRAME_POINTER_REGNUM},	\
579  {FRAME_POINTER_REGNUM, STACK_POINTER_REGNUM}}
580
581#define INITIAL_ELIMINATION_OFFSET(FROM, TO, OFFSET) \
582 (OFFSET) = mmix_initial_elimination_offset (FROM, TO)
583
584
585/* Node: Stack Arguments */
586
587#define ACCUMULATE_OUTGOING_ARGS 1
588
589#define RETURN_POPS_ARGS(FUNDECL, FUNTYPE, STACKSIZE) 0
590
591
592/* Node: Register Arguments */
593#define FUNCTION_ARG(CUM, MODE, TYPE, NAMED)	\
594 mmix_function_arg (&(CUM), MODE, TYPE, NAMED, 0)
595
596#define FUNCTION_INCOMING_ARG(CUM, MODE, TYPE, NAMED)	\
597 mmix_function_arg (&(CUM), MODE, TYPE, NAMED, 1)
598
599typedef struct { int regs; int lib; } CUMULATIVE_ARGS;
600
601#define INIT_CUMULATIVE_ARGS(CUM, FNTYPE, LIBNAME, INDIRECT, N_NAMED_ARGS) \
602 ((CUM).regs = 0, (CUM).lib = ((LIBNAME) != 0))
603
604#define FUNCTION_ARG_ADVANCE(CUM, MODE, TYPE, NAMED)		\
605 ((CUM).regs							\
606  = ((targetm.calls.must_pass_in_stack (MODE, TYPE))		\
607     || (MMIX_FUNCTION_ARG_SIZE (MODE, TYPE) > 8		\
608	 && !TARGET_LIBFUNC && !(CUM).lib))			\
609  ? (MMIX_MAX_ARGS_IN_REGS) + 1					\
610  : (CUM).regs + (7 + (MMIX_FUNCTION_ARG_SIZE (MODE, TYPE))) / 8)
611
612#define FUNCTION_ARG_REGNO_P(REGNO)		\
613 mmix_function_arg_regno_p (REGNO, 0)
614
615
616/* Node: Register Arguments */
617
618#define FUNCTION_VALUE(VALTYPE, FUNC)  \
619 gen_rtx_REG (TYPE_MODE (VALTYPE), MMIX_RETURN_VALUE_REGNUM)
620
621/* This needs to take care of the register hole for complex return values.  */
622#define FUNCTION_OUTGOING_VALUE(VALTYPE, FUNC)  \
623 mmix_function_outgoing_value (VALTYPE, FUNC)
624
625#define LIBCALL_VALUE(MODE) \
626 gen_rtx_REG (MODE, MMIX_RETURN_VALUE_REGNUM)
627
628#define FUNCTION_VALUE_REGNO_P(REGNO) \
629 mmix_function_value_regno_p (REGNO)
630
631
632/* Node: Caller Saves */
633/* (empty) */
634
635
636/* Node: Function Entry */
637
638/* See mmix.c for TARGET_ASM_FUNCTION_PROLOGUE and
639   TARGET_ASM_FUNCTION_EPILOGUE.  */
640
641/* We need to say that the epilogue uses the return address, so the
642   initial-value machinery restores it.  FIXME: Some targets
643   conditionalize on "reload_completed &&".  Investigate difference.
644   FIXME: Not needed if nonlocal_goto_stack_level.  */
645#define EPILOGUE_USES(REGNO) \
646 ((REGNO) == MMIX_INCOMING_RETURN_ADDRESS_REGNUM)
647
648/* Node: Profiling */
649#define FUNCTION_PROFILER(FILE, LABELNO)	\
650 mmix_function_profiler (FILE, LABELNO)
651
652/* Node: Trampolines */
653
654#define TRAMPOLINE_SIZE		(4*UNITS_PER_WORD)
655#define TRAMPOLINE_ALIGNMENT	BITS_PER_WORD
656
657/* Node: Addressing Modes */
658
659#define CONSTANT_ADDRESS_P(X) \
660 mmix_constant_address_p (X)
661
662#define MAX_REGS_PER_ADDRESS 2
663
664#ifndef REG_OK_STRICT
665# define REG_OK_FOR_BASE_P(X)			\
666  (REGNO (X) <= MMIX_LAST_GENERAL_REGISTER	\
667   || REGNO (X) == MMIX_ARG_POINTER_REGNUM	\
668   || REGNO (X) >= FIRST_PSEUDO_REGISTER)
669#else
670# define REG_OK_FOR_BASE_P(X) REGNO_OK_FOR_BASE_P (REGNO (X))
671#endif /* REG_OK_STRICT */
672
673#define REG_OK_FOR_INDEX_P(X) REG_OK_FOR_BASE_P (X)
674
675#define LEGITIMATE_CONSTANT_P(X) \
676 mmix_legitimate_constant_p (X)
677
678
679/* Node: Condition Code */
680
681#define SELECT_CC_MODE(OP, X, Y)		\
682 mmix_select_cc_mode (OP, X, Y)
683
684/* A definition of CANONICALIZE_COMPARISON that changed LE and GT
685   comparisons with -1 to LT and GE respectively, and LT, LTU, GE or GEU
686   comparisons with 256 to 255 and LE, LEU, GT and GTU has been
687   ineffective; the code path for performing the changes did not trig for
688   neither the GCC testsuite nor ghostscript-6.52 nor Knuth's mmix.tar.gz
689   itself (core GCC functionality supposedly handling it) with sources
690   from 2002-06-06.  */
691
692#define REVERSIBLE_CC_MODE(MODE)		\
693 mmix_reversible_cc_mode (MODE)
694
695
696/* Node: Costs */
697
698/* The special registers can only move to and from general regs, and we
699   need to check that their constraints match, so say 3 for them.  */
700/* WARNING: gcc-2.7.2.2 i686-pc-linux-gnulibc1 (as shipped with RH 4.2)
701   miscompiles reload1.c:reload_cse_simplify_set; a call to
702   reload_cse_regno_equal_p is missing when checking if a substitution of
703   a register setting is valid if this is defined to just the expression
704   in mmix_register_move_cost.
705
706   Symptom: a (all?) register setting is optimized away for e.g.
707   "char *p1(char *p) { return p+1; }" and the value of register zero ($0)
708   is returned.
709
710   We can workaround by making this a function call - unknown if this
711   causes dire speed effects.  */
712#define REGISTER_MOVE_COST(MODE, FROM, TO) \
713 mmix_register_move_cost (MODE, FROM, TO)
714
715#define SLOW_BYTE_ACCESS 0
716
717
718/* Node: Sections */
719
720/* This must be a constant string, since it's used in crtstuff.c.  */
721#define TEXT_SECTION_ASM_OP \
722 "\t.text ! mmixal:= 9H LOC 8B"
723
724/* FIXME: Not documented.  */
725#define DATA_SECTION_ASM_OP \
726 mmix_data_section_asm_op ()
727
728#define READONLY_DATA_SECTION_ASM_OP	"\t.section\t.rodata"
729
730/* Node: PIC */
731/* (empty) */
732
733
734/* Node: File Framework */
735
736/* While any other punctuation character but ";" would do, we prefer "%"
737   or "!"; "!" is an unary operator and so will not be mistakenly included
738   in correctly formed expressions.  The hash character adds mass; catches
739   the eye.  We can't have it as a comment char by itself, since it's a
740   hex-number prefix.  */
741#define ASM_COMMENT_START "!#"
742
743/* These aren't currently functional.  We just keep them as markers.  */
744#define ASM_APP_ON "%APP\n"
745#define ASM_APP_OFF "%NO_APP\n"
746
747#define ASM_OUTPUT_SOURCE_FILENAME(STREAM, NAME) \
748 mmix_asm_output_source_filename (STREAM, NAME)
749
750#define OUTPUT_QUOTED_STRING(STREAM, STRING) \
751 mmix_output_quoted_string (STREAM, STRING, strlen (STRING))
752
753#define TARGET_ASM_NAMED_SECTION default_elf_asm_named_section
754
755/* Node: Data Output */
756
757#define ASM_OUTPUT_ASCII(STREAM, PTR, LEN) \
758 mmix_asm_output_ascii (STREAM, PTR, LEN)
759
760/* Node: Uninitialized Data */
761
762#define ASM_OUTPUT_ALIGNED_COMMON(ST, N, S, A) \
763 mmix_asm_output_aligned_common (ST, N, S, A)
764
765#define ASM_OUTPUT_ALIGNED_LOCAL(ST, N, S, A) \
766 mmix_asm_output_aligned_local (ST, N, S, A)
767
768
769/* Node: Label Output */
770
771#define ASM_OUTPUT_LABEL(STREAM, NAME) \
772 mmix_asm_output_label (STREAM, NAME)
773
774#define ASM_OUTPUT_INTERNAL_LABEL(STREAM, NAME) \
775 mmix_asm_output_internal_label (STREAM, NAME)
776
777#define ASM_DECLARE_REGISTER_GLOBAL(STREAM, DECL, REGNO, NAME) \
778 mmix_asm_declare_register_global (STREAM, DECL, REGNO, NAME)
779
780#define GLOBAL_ASM_OP "\t.global "
781
782#define ASM_WEAKEN_LABEL(STREAM, NAME) \
783 mmix_asm_weaken_label (STREAM, NAME)
784
785#define MAKE_DECL_ONE_ONLY(DECL) \
786 mmix_make_decl_one_only (DECL)
787
788#define ASM_OUTPUT_LABELREF(STREAM, NAME) \
789 mmix_asm_output_labelref (STREAM, NAME)
790
791/* We insert a ":" to disambiguate against user symbols like L5.  */
792#define ASM_GENERATE_INTERNAL_LABEL(LABEL, PREFIX, NUM) \
793 sprintf (LABEL, "*%s:%ld", PREFIX, (long)(NUM))
794
795/* Insert "::"; these are rarer than internal labels.  FIXME: Make sure no
796   ":" is seen in the object file; we don't really want that mmixal
797   feature visible there.  We don't want the default, which uses a dot;
798   that'd be incompatible with mmixal.  */
799#define ASM_PN_FORMAT "%s::%lu"
800
801#define ASM_OUTPUT_DEF(STREAM, NAME, VALUE) \
802 mmix_asm_output_def (STREAM, NAME, VALUE)
803
804/* Node: Macros for Initialization */
805/* We're compiling to ELF and linking to MMO; fundamental ELF features
806   that GCC depend on are there.  */
807
808/* These must be constant strings, since they're used in crtstuff.c.  */
809#define INIT_SECTION_ASM_OP "\t.section .init,\"ax\" ! mmixal-incompatible"
810
811#define FINI_SECTION_ASM_OP "\t.section .fini,\"ax\" ! mmixal-incompatible"
812
813#define OBJECT_FORMAT_ELF
814
815
816/* Node: Instruction Output */
817
818/* The non-$ register names must be prefixed with ":", since they're
819   affected by PREFIX.  We provide the non-colon names as additional
820   names.  */
821#define REGISTER_NAMES							\
822 {"$0", "$1", "$2", "$3", "$4", "$5", "$6", "$7",			\
823  "$8", "$9", "$10", "$11", "$12", "$13", "$14", "$15",			\
824  "$16", "$17", "$18", "$19", "$20", "$21", "$22", "$23",		\
825  "$24", "$25", "$26", "$27", "$28", "$29", "$30", "$31",		\
826  "$32", "$33", "$34", "$35", "$36", "$37", "$38", "$39",		\
827  "$40", "$41", "$42", "$43", "$44", "$45", "$46", "$47",		\
828  "$48", "$49", "$50", "$51", "$52", "$53", "$54", "$55",		\
829  "$56", "$57", "$58", "$59", "$60", "$61", "$62", "$63",		\
830  "$64", "$65", "$66", "$67", "$68", "$69", "$70", "$71",		\
831  "$72", "$73", "$74", "$75", "$76", "$77", "$78", "$79",		\
832  "$80", "$81", "$82", "$83", "$84", "$85", "$86", "$87",		\
833  "$88", "$89", "$90", "$91", "$92", "$93", "$94", "$95",		\
834  "$96", "$97", "$98", "$99", "$100", "$101", "$102", "$103",		\
835  "$104", "$105", "$106", "$107", "$108", "$109", "$110", "$111",	\
836  "$112", "$113", "$114", "$115", "$116", "$117", "$118", "$119",	\
837  "$120", "$121", "$122", "$123", "$124", "$125", "$126", "$127",	\
838  "$128", "$129", "$130", "$131", "$132", "$133", "$134", "$135",	\
839  "$136", "$137", "$138", "$139", "$140", "$141", "$142", "$143",	\
840  "$144", "$145", "$146", "$147", "$148", "$149", "$150", "$151",	\
841  "$152", "$153", "$154", "$155", "$156", "$157", "$158", "$159",	\
842  "$160", "$161", "$162", "$163", "$164", "$165", "$166", "$167",	\
843  "$168", "$169", "$170", "$171", "$172", "$173", "$174", "$175",	\
844  "$176", "$177", "$178", "$179", "$180", "$181", "$182", "$183",	\
845  "$184", "$185", "$186", "$187", "$188", "$189", "$190", "$191",	\
846  "$192", "$193", "$194", "$195", "$196", "$197", "$198", "$199",	\
847  "$200", "$201", "$202", "$203", "$204", "$205", "$206", "$207",	\
848  "$208", "$209", "$210", "$211", "$212", "$213", "$214", "$215",	\
849  "$216", "$217", "$218", "$219", "$220", "$221", "$222", "$223",	\
850  "$224", "$225", "$226", "$227", "$228", "$229", "$230", "$231",	\
851  "$232", "$233", "$234", "$235", "$236", "$237", "$238", "$239",	\
852  "$240", "$241", "$242", "$243", "$244", "$245", "$246", "$247",	\
853  "$248", "$249", "$250", "$251", "$252", "$253", "$254", "$255",	\
854  ":rD",  ":rE",  ":rH",  ":rJ",  ":rR",  "ap_!BAD!", ":rO"}
855
856#define ADDITIONAL_REGISTER_NAMES			\
857 {{"sp", 254}, {":sp", 254}, {"rD", 256}, {"rE", 257},	\
858  {"rH", 258}, {"rJ", MMIX_rJ_REGNUM}, {"rO", MMIX_rO_REGNUM}}
859
860#define PRINT_OPERAND(STREAM, X, CODE) \
861 mmix_print_operand (STREAM, X, CODE)
862
863#define PRINT_OPERAND_PUNCT_VALID_P(CODE) \
864 mmix_print_operand_punct_valid_p (CODE)
865
866#define PRINT_OPERAND_ADDRESS(STREAM, X) \
867 mmix_print_operand_address (STREAM, X)
868
869#define ASM_OUTPUT_REG_PUSH(STREAM, REGNO) \
870 mmix_asm_output_reg_push (STREAM, REGNO)
871
872#define ASM_OUTPUT_REG_POP(STREAM, REGNO) \
873 mmix_asm_output_reg_pop (STREAM, REGNO)
874
875
876/* Node: Dispatch Tables */
877
878/* We define both types, since SImode is the better, but DImode the only
879   possible for mmixal so that's the one actually used.  */
880#define ASM_OUTPUT_ADDR_DIFF_ELT(STREAM, BODY, VALUE, REL) \
881 mmix_asm_output_addr_diff_elt (STREAM, BODY, VALUE, REL)
882
883#define ASM_OUTPUT_ADDR_VEC_ELT(STREAM, VALUE) \
884 mmix_asm_output_addr_vec_elt (STREAM, VALUE)
885
886
887/* Node: Exception Region Output */
888/* (empty) */
889
890/* Node: Alignment Output */
891
892#define ASM_OUTPUT_SKIP(STREAM, NBYTES) \
893 mmix_asm_output_skip (STREAM, NBYTES)
894
895#define ASM_OUTPUT_ALIGN(STREAM, POWER) \
896 mmix_asm_output_align (STREAM, POWER)
897
898
899/* Node: All Debuggers */
900
901#define DBX_REGISTER_NUMBER(REGNO) \
902 mmix_dbx_register_number (REGNO)
903
904
905/* Node: DBX Options */
906/* (empty) */
907/* Node: DBX Hooks */
908/* (empty) */
909/* Node: File Names and DBX */
910/* (empty) */
911
912
913/* Node: SDB and DWARF */
914#define DWARF2_DEBUGGING_INFO 1
915#define DWARF2_ASM_LINE_DEBUG_INFO 1
916
917/* Node: Misc */
918
919/* There's no way to get a PC-relative offset into tables for SImode, so
920   for the moment we have absolute entries in DImode.
921   When we're going ELF, these should be SImode and 1.  */
922#define CASE_VECTOR_MODE DImode
923#define CASE_VECTOR_PC_RELATIVE 0
924
925#define WORD_REGISTER_OPERATIONS
926
927/* We have a choice, which makes this yet another parameter to tweak.  The
928   gut feeling is currently that SIGN_EXTEND wins; "int" is more frequent
929   than "unsigned int", and we have signed characters.  FIXME: measure.  */
930#define LOAD_EXTEND_OP(MODE) (TARGET_ZERO_EXTEND ? ZERO_EXTEND : SIGN_EXTEND)
931
932#define MOVE_MAX 8
933
934#define TRULY_NOOP_TRUNCATION(OUTPREC, INPREC) 1
935
936/* ??? MMIX allows a choice of STORE_FLAG_VALUE.  Revisit later,
937   we don't have scc expanders yet.  */
938
939#define Pmode DImode
940
941#define FUNCTION_MODE QImode
942
943#define NO_IMPLICIT_EXTERN_C
944
945#define HANDLE_SYSV_PRAGMA 1
946
947/* These are checked.  */
948#define DOLLARS_IN_IDENTIFIERS 0
949#define NO_DOLLAR_IN_LABEL
950#define NO_DOT_IN_LABEL
951
952#endif /* GCC_MMIX_H */
953/*
954 * Local variables:
955 * eval: (c-set-style "gnu")
956 * indent-tabs-mode: t
957 * End:
958 */
959