1/* Target Code for moxie
2   Copyright (C) 2008, 2009, 2010  Free Software Foundation
3   Contributed by Anthony Green.
4
5   This file is part of GCC.
6
7   GCC is free software; you can redistribute it and/or modify it
8   under the terms of the GNU General Public License as published
9   by the Free Software Foundation; either version 3, or (at your
10   option) any later version.
11
12   GCC is distributed in the hope that it will be useful, but WITHOUT
13   ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
14   or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public
15   License for more details.
16
17   You should have received a copy of the GNU General Public License
18   along with GCC; see the file COPYING3.  If not see
19   <http://www.gnu.org/licenses/>.  */
20
21#include "config.h"
22#include "system.h"
23#include "coretypes.h"
24#include "tm.h"
25#include "rtl.h"
26#include "regs.h"
27#include "hard-reg-set.h"
28#include "real.h"
29#include "insn-config.h"
30#include "conditions.h"
31#include "insn-flags.h"
32#include "output.h"
33#include "insn-attr.h"
34#include "flags.h"
35#include "recog.h"
36#include "reload.h"
37#include "toplev.h"
38#include "obstack.h"
39#include "tree.h"
40#include "expr.h"
41#include "optabs.h"
42#include "except.h"
43#include "function.h"
44#include "ggc.h"
45#include "target.h"
46#include "target-def.h"
47#include "tm_p.h"
48#include "langhooks.h"
49#include "df.h"
50
51#define LOSE_AND_RETURN(msgid, x)		\
52  do						\
53    {						\
54      moxie_operand_lossage (msgid, x);		\
55      return;					\
56    } while (0)
57
58/* Worker function for TARGET_RETURN_IN_MEMORY.  */
59
60static bool
61moxie_return_in_memory (const_tree type, const_tree fntype ATTRIBUTE_UNUSED)
62{
63  const HOST_WIDE_INT size = int_size_in_bytes (type);
64  return (size == -1 || size > 2 * UNITS_PER_WORD);
65}
66
67/* Define how to find the value returned by a function.
68   VALTYPE is the data type of the value (as a tree).
69   If the precise function being called is known, FUNC is its
70   FUNCTION_DECL; otherwise, FUNC is 0.
71
72   We always return values in register $r0 for moxie.  */
73
74rtx
75moxie_function_value (const_tree valtype,
76		      const_tree fntype_or_decl ATTRIBUTE_UNUSED,
77		      bool outgoing ATTRIBUTE_UNUSED)
78{
79  return gen_rtx_REG (TYPE_MODE (valtype), MOXIE_R0);
80}
81
82/* Emit an error message when we're in an asm, and a fatal error for
83   "normal" insns.  Formatted output isn't easily implemented, since we
84   use output_operand_lossage to output the actual message and handle the
85   categorization of the error.  */
86
87static void
88moxie_operand_lossage (const char *msgid, rtx op)
89{
90  debug_rtx (op);
91  output_operand_lossage ("%s", msgid);
92}
93
94/* The PRINT_OPERAND_ADDRESS worker.  */
95
96void
97moxie_print_operand_address (FILE *file, rtx x)
98{
99  switch (GET_CODE (x))
100    {
101    case REG:
102      fprintf (file, "(%s)", reg_names[REGNO (x)]);
103      break;
104
105    case PLUS:
106      switch (GET_CODE (XEXP (x, 1)))
107	{
108	case CONST_INT:
109	  fprintf (file, "%ld(%s)",
110		   INTVAL(XEXP (x, 1)), reg_names[REGNO (XEXP (x, 0))]);
111	  break;
112	case SYMBOL_REF:
113	  output_addr_const (file, XEXP (x, 1));
114	  fprintf (file, "(%s)", reg_names[REGNO (XEXP (x, 0))]);
115	  break;
116	case CONST:
117	  {
118	    rtx plus = XEXP (XEXP (x, 1), 0);
119	    if (GET_CODE (XEXP (plus, 0)) == SYMBOL_REF
120		&& CONST_INT_P (XEXP (plus, 1)))
121	      {
122		output_addr_const(file, XEXP (plus, 0));
123		fprintf (file,"+%ld(%s)", INTVAL (XEXP (plus, 1)),
124			 reg_names[REGNO (XEXP (x, 0))]);
125	      }
126	    else
127	      abort();
128	  }
129	  break;
130	default:
131	  abort();
132	}
133      break;
134
135    default:
136      output_addr_const (file, x);
137      break;
138    }
139}
140
141/* The PRINT_OPERAND worker.  */
142
143void
144moxie_print_operand (FILE *file, rtx x, int code)
145{
146  rtx operand = x;
147
148  /* New code entries should just be added to the switch below.  If
149     handling is finished, just return.  If handling was just a
150     modification of the operand, the modified operand should be put in
151     "operand", and then do a break to let default handling
152     (zero-modifier) output the operand.  */
153
154  switch (code)
155    {
156    case 0:
157      /* No code, print as usual.  */
158      break;
159
160    default:
161      LOSE_AND_RETURN ("invalid operand modifier letter", x);
162    }
163
164  /* Print an operand as without a modifier letter.  */
165  switch (GET_CODE (operand))
166    {
167    case REG:
168      if (REGNO (operand) > MOXIE_R13)
169	internal_error ("internal error: bad register: %d", REGNO (operand));
170      fprintf (file, "%s", reg_names[REGNO (operand)]);
171      return;
172
173    case MEM:
174      output_address (XEXP (operand, 0));
175      return;
176
177    default:
178      /* No need to handle all strange variants, let output_addr_const
179	 do it for us.  */
180      if (CONSTANT_P (operand))
181	{
182	  output_addr_const (file, operand);
183	  return;
184	}
185
186      LOSE_AND_RETURN ("unexpected operand", x);
187    }
188}
189
190/* Per-function machine data.  */
191struct GTY(()) machine_function
192 {
193   /* Number of bytes saved on the stack for callee saved registers.  */
194   int callee_saved_reg_size;
195
196   /* Number of bytes saved on the stack for local variables.  */
197   int local_vars_size;
198
199   /* The sum of 2 sizes: locals vars and padding byte for saving the
200    * registers.  Used in expand_prologue () and expand_epilogue().  */
201   int size_for_adjusting_sp;
202 };
203
204/* Zero initialization is OK for all current fields.  */
205
206static struct machine_function *
207moxie_init_machine_status (void)
208{
209  return GGC_CNEW (struct machine_function);
210}
211
212
213/* The OVERRIDE_OPTIONS worker.
214   All this curently does is set init_machine_status.  */
215void
216moxie_override_options (void)
217{
218  /* Set the per-function-data initializer.  */
219  init_machine_status = moxie_init_machine_status;
220}
221
222/* Compute the size of the local area and the size to be adjusted by the
223 * prologue and epilogue.  */
224
225static void
226moxie_compute_frame (void)
227{
228  /* For aligning the local variables.  */
229  int stack_alignment = STACK_BOUNDARY / BITS_PER_UNIT;
230  int padding_locals;
231  int regno;
232
233  /* Padding needed for each element of the frame.  */
234  cfun->machine->local_vars_size = get_frame_size ();
235
236  /* Align to the stack alignment.  */
237  padding_locals = cfun->machine->local_vars_size % stack_alignment;
238  if (padding_locals)
239    padding_locals = stack_alignment - padding_locals;
240
241  cfun->machine->local_vars_size += padding_locals;
242
243  cfun->machine->callee_saved_reg_size = 0;
244
245  /* Save callee-saved registers.  */
246  for (regno = 0; regno < FIRST_PSEUDO_REGISTER; regno++)
247    if (df_regs_ever_live_p (regno) && (! call_used_regs[regno]))
248      cfun->machine->callee_saved_reg_size += 4;
249
250  cfun->machine->size_for_adjusting_sp =
251    crtl->args.pretend_args_size
252    + cfun->machine->local_vars_size
253    + (ACCUMULATE_OUTGOING_ARGS ? crtl->outgoing_args_size : 0);
254}
255
256void
257moxie_expand_prologue (void)
258{
259  int regno;
260  rtx insn;
261
262  moxie_compute_frame ();
263
264  /* Save callee-saved registers.  */
265  for (regno = 0; regno < FIRST_PSEUDO_REGISTER; regno++)
266    {
267      if (!fixed_regs[regno] && df_regs_ever_live_p (regno) && !call_used_regs[regno])
268	{
269	  insn = emit_insn (gen_movsi_push (gen_rtx_REG (Pmode, regno)));
270	  RTX_FRAME_RELATED_P (insn) = 1;
271	}
272    }
273
274  if (cfun->machine->size_for_adjusting_sp > 0)
275    {
276      int i = cfun->machine->size_for_adjusting_sp;
277      while (i > 255)
278	{
279	  insn = emit_insn (gen_subsi3 (stack_pointer_rtx,
280					stack_pointer_rtx,
281					GEN_INT (255)));
282	  RTX_FRAME_RELATED_P (insn) = 1;
283	  i -= 255;
284	}
285      if (i > 0)
286	{
287	  insn = emit_insn (gen_subsi3 (stack_pointer_rtx,
288					stack_pointer_rtx,
289					GEN_INT (i)));
290	  RTX_FRAME_RELATED_P (insn) = 1;
291	}
292    }
293}
294
295void
296moxie_expand_epilogue (void)
297{
298  int regno;
299  rtx insn, reg, cfa_restores = NULL;
300
301  if (cfun->machine->callee_saved_reg_size != 0)
302    {
303      reg = gen_rtx_REG (Pmode, MOXIE_R5);
304      if (cfun->machine->callee_saved_reg_size <= 255)
305	{
306	  emit_move_insn (reg, hard_frame_pointer_rtx);
307	  emit_insn (gen_subsi3
308		     (reg, reg,
309		      GEN_INT (cfun->machine->callee_saved_reg_size)));
310	}
311      else
312	{
313	  emit_move_insn (reg,
314			  GEN_INT (-cfun->machine->callee_saved_reg_size));
315	  emit_insn (gen_addsi3 (reg, reg, hard_frame_pointer_rtx));
316	}
317      for (regno = FIRST_PSEUDO_REGISTER; regno-- > 0; )
318	if (!fixed_regs[regno] && !call_used_regs[regno]
319	    && df_regs_ever_live_p (regno))
320	  {
321	    rtx preg = gen_rtx_REG (Pmode, regno);
322	    insn = emit_insn (gen_movsi_pop (reg, preg));
323	  }
324    }
325
326  emit_jump_insn (gen_returner ());
327}
328
329/* Implements the macro INITIAL_ELIMINATION_OFFSET, return the OFFSET.  */
330
331int
332moxie_initial_elimination_offset (int from, int to)
333{
334  int ret;
335
336  if ((from) == FRAME_POINTER_REGNUM && (to) == HARD_FRAME_POINTER_REGNUM)
337    {
338      /* Compute this since we need to use cfun->machine->local_vars_size.  */
339      moxie_compute_frame ();
340      ret = -cfun->machine->callee_saved_reg_size;
341    }
342  else if ((from) == ARG_POINTER_REGNUM && (to) == HARD_FRAME_POINTER_REGNUM)
343    ret = 0x00;
344  else
345    abort ();
346
347  return ret;
348}
349
350/* Worker function for TARGET_SETUP_INCOMING_VARARGS.  */
351
352static void
353moxie_setup_incoming_varargs (CUMULATIVE_ARGS *cum,
354			      enum machine_mode mode ATTRIBUTE_UNUSED,
355			      tree type ATTRIBUTE_UNUSED,
356			      int *pretend_size, int no_rtl)
357{
358  int regno;
359  int regs = 8 - *cum;
360
361  *pretend_size = regs < 0 ? 0 : GET_MODE_SIZE (SImode) * regs;
362
363  if (no_rtl)
364    return;
365
366  for (regno = *cum; regno < 8; regno++)
367    {
368      rtx reg = gen_rtx_REG (SImode, regno);
369      rtx slot = gen_rtx_PLUS (Pmode,
370			       gen_rtx_REG (SImode, ARG_POINTER_REGNUM),
371			       GEN_INT (UNITS_PER_WORD * (3 + (regno-2))));
372
373      emit_move_insn (gen_rtx_MEM (SImode, slot), reg);
374    }
375}
376
377
378/* Return the fixed registers used for condition codes.  */
379
380static bool
381moxie_fixed_condition_code_regs (unsigned int *p1, unsigned int *p2)
382{
383  *p1 = CC_REG;
384  *p2 = INVALID_REGNUM;
385  return true;
386}
387
388/* Return the next register to be used to hold a function argument or
389   NULL_RTX if there's no more space.  */
390
391rtx
392moxie_function_arg (CUMULATIVE_ARGS cum, enum machine_mode mode,
393		    tree type ATTRIBUTE_UNUSED, int named ATTRIBUTE_UNUSED)
394{
395  if (cum < 8)
396    return gen_rtx_REG (mode, cum);
397  else
398    return NULL_RTX;
399}
400
401/* Return non-zero if the function argument described by TYPE is to be
402   passed by reference.  */
403
404static bool
405moxie_pass_by_reference (CUMULATIVE_ARGS *cum ATTRIBUTE_UNUSED,
406			 enum machine_mode mode, const_tree type,
407			 bool named ATTRIBUTE_UNUSED)
408{
409  unsigned HOST_WIDE_INT size;
410
411  if (type)
412    {
413      if (AGGREGATE_TYPE_P (type))
414	return true;
415      size = int_size_in_bytes (type);
416    }
417  else
418    size = GET_MODE_SIZE (mode);
419
420  return size > 4*6;
421}
422
423/* Some function arguments will only partially fit in the registers
424   that hold arguments.  Given a new arg, return the number of bytes
425   that fit in argument passing registers.  */
426
427static int
428moxie_arg_partial_bytes (CUMULATIVE_ARGS *cum,
429			 enum machine_mode mode,
430			 tree type, bool named)
431{
432  int bytes_left, size;
433
434  if (*cum >= 8)
435    return 0;
436
437  if (moxie_pass_by_reference (cum, mode, type, named))
438    size = 4;
439  else if (type)
440    {
441      if (AGGREGATE_TYPE_P (type))
442	return 0;
443      size = int_size_in_bytes (type);
444    }
445  else
446    size = GET_MODE_SIZE (mode);
447
448  bytes_left = (4 * 6) - ((*cum - 2) * 4);
449
450  if (size > bytes_left)
451    return bytes_left;
452  else
453    return 0;
454}
455
456/* Worker function for TARGET_STATIC_CHAIN.  */
457
458static rtx
459moxie_static_chain (const_tree fndecl, bool incoming_p)
460{
461  rtx addr, mem;
462
463  if (!DECL_STATIC_CHAIN (fndecl))
464    return NULL;
465
466  if (incoming_p)
467    addr = plus_constant (arg_pointer_rtx, 2 * UNITS_PER_WORD);
468  else
469    addr = plus_constant (stack_pointer_rtx, -UNITS_PER_WORD);
470
471  mem = gen_rtx_MEM (Pmode, addr);
472  MEM_NOTRAP_P (mem) = 1;
473
474  return mem;
475}
476
477/* Worker function for TARGET_ASM_TRAMPOLINE_TEMPLATE.  */
478
479static void
480moxie_asm_trampoline_template (FILE *f)
481{
482  fprintf (f, "\tpush  $sp, $r0\n");
483  fprintf (f, "\tldi.l $r0, 0x0\n");
484  fprintf (f, "\tsto.l 0x8($fp), $r0\n");
485  fprintf (f, "\tpop   $sp, $r0\n");
486  fprintf (f, "\tnop\n");
487  fprintf (f, "\tjmpa  0x0\n");
488}
489
490/* Worker function for TARGET_TRAMPOLINE_INIT.  */
491
492static void
493moxie_trampoline_init (rtx m_tramp, tree fndecl, rtx chain_value)
494{
495  rtx mem, fnaddr = XEXP (DECL_RTL (fndecl), 0);
496
497  emit_block_move (m_tramp, assemble_trampoline_template (),
498		   GEN_INT (TRAMPOLINE_SIZE), BLOCK_OP_NORMAL);
499
500  mem = adjust_address (m_tramp, SImode, 4);
501  emit_move_insn (mem, chain_value);
502  mem = adjust_address (m_tramp, SImode, 20);
503  emit_move_insn (mem, fnaddr);
504}
505
506/* The Global `targetm' Variable.  */
507
508/* Initialize the GCC target structure.  */
509
510#undef  TARGET_PROMOTE_PROTOTYPES
511#define TARGET_PROMOTE_PROTOTYPES	hook_bool_const_tree_true
512
513#undef  TARGET_RETURN_IN_MEMORY
514#define TARGET_RETURN_IN_MEMORY		moxie_return_in_memory
515#undef  TARGET_MUST_PASS_IN_STACK
516#define TARGET_MUST_PASS_IN_STACK	must_pass_in_stack_var_size
517#undef  TARGET_PASS_BY_REFERENCE
518#define TARGET_PASS_BY_REFERENCE        moxie_pass_by_reference
519#undef  TARGET_ARG_PARTIAL_BYTES
520#define TARGET_ARG_PARTIAL_BYTES        moxie_arg_partial_bytes
521
522
523#undef  TARGET_SETUP_INCOMING_VARARGS
524#define TARGET_SETUP_INCOMING_VARARGS 	moxie_setup_incoming_varargs
525
526#undef	TARGET_FIXED_CONDITION_CODE_REGS
527#define	TARGET_FIXED_CONDITION_CODE_REGS moxie_fixed_condition_code_regs
528
529/* Define this to return an RTX representing the place where a
530   function returns or receives a value of data type RET_TYPE, a tree
531   node node representing a data type.  */
532#undef TARGET_FUNCTION_VALUE
533#define TARGET_FUNCTION_VALUE moxie_function_value
534
535#undef TARGET_FRAME_POINTER_REQUIRED
536#define TARGET_FRAME_POINTER_REQUIRED hook_bool_void_true
537
538#undef TARGET_STATIC_CHAIN
539#define TARGET_STATIC_CHAIN moxie_static_chain
540#undef TARGET_ASM_TRAMPOLINE_TEMPLATE
541#define TARGET_ASM_TRAMPOLINE_TEMPLATE moxie_asm_trampoline_template
542#undef TARGET_TRAMPOLINE_INIT
543#define TARGET_TRAMPOLINE_INIT moxie_trampoline_init
544
545struct gcc_target targetm = TARGET_INITIALIZER;
546
547#include "gt-moxie.h"
548