aboutsummaryrefslogtreecommitdiff
path: root/gcc/convert.c
blob: 4ac23a7f44ce8c9f66f99e3f7309987514fefe24 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
/* Utility routines for data type conversion for GNU C.
   Copyright (C) 1987, 1988, 1991, 1992, 1993, 1994, 1995, 1997, 1998,
   2000, 2001, 2002, 2003 Free Software Foundation, Inc.

This file is part of GCC.

GCC is free software; you can redistribute it and/or modify it under
the terms of the GNU General Public License as published by the Free
Software Foundation; either version 2, or (at your option) any later
version.

GCC is distributed in the hope that it will be useful, but WITHOUT ANY
WARRANTY; without even the implied warranty of MERCHANTABILITY or
FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
for more details.

You should have received a copy of the GNU General Public License
along with GCC; see the file COPYING.  If not, write to the Free
Software Foundation, 59 Temple Place - Suite 330, Boston, MA
02111-1307, USA.  */


/* These routines are somewhat language-independent utility function
   intended to be called by the language-specific convert () functions.  */

#include "config.h"
#include "system.h"
#include "coretypes.h"
#include "tm.h"
#include "tree.h"
#include "flags.h"
#include "convert.h"
#include "toplev.h"
#include "langhooks.h"
#include "real.h"
/* Convert EXPR to some pointer or reference type TYPE.

   EXPR must be pointer, reference, integer, enumeral, or literal zero;
   in other cases error is called.  */

tree
convert_to_pointer (type, expr)
     tree type, expr;
{
  if (integer_zerop (expr))
    {
      expr = build_int_2 (0, 0);
      TREE_TYPE (expr) = type;
      return expr;
    }

  switch (TREE_CODE (TREE_TYPE (expr)))
    {
    case POINTER_TYPE:
    case REFERENCE_TYPE:
      return build1 (NOP_EXPR, type, expr);

    case INTEGER_TYPE:
    case ENUMERAL_TYPE:
    case BOOLEAN_TYPE:
    case CHAR_TYPE:
      if (TYPE_PRECISION (TREE_TYPE (expr)) == POINTER_SIZE)
	return build1 (CONVERT_EXPR, type, expr);

      return
	convert_to_pointer (type,
			    convert ((*lang_hooks.types.type_for_size)
				     (POINTER_SIZE, 0), expr));

    default:
      error ("cannot convert to a pointer type");
      return convert_to_pointer (type, integer_zero_node);
    }
}

/* Avoid any floating point extensions from EXP.  */
tree
strip_float_extensions (exp)
     tree exp;
{
  tree sub, expt, subt;

  /*  For floating point constant look up the narrowest type that can hold
      it properly and handle it like (type)(narrowest_type)constant.
      This way we can optimize for instance a=a*2.0 where "a" is float
      but 2.0 is double constant.  */
  if (TREE_CODE (exp) == REAL_CST)
    {
      REAL_VALUE_TYPE orig;
      tree type = NULL;

      orig = TREE_REAL_CST (exp);
      if (TYPE_PRECISION (TREE_TYPE (exp)) > TYPE_PRECISION (float_type_node)
	  && exact_real_truncate (TYPE_MODE (float_type_node), &orig))
	type = float_type_node;
      else if (TYPE_PRECISION (TREE_TYPE (exp))
	       > TYPE_PRECISION (double_type_node)
	       && exact_real_truncate (TYPE_MODE (double_type_node), &orig))
	type = double_type_node;
      if (type)
	return build_real (type, real_value_truncate (TYPE_MODE (type), orig));
    }

  if (TREE_CODE (exp) != NOP_EXPR)
    return exp;

  sub = TREE_OPERAND (exp, 0);
  subt = TREE_TYPE (sub);
  expt = TREE_TYPE (exp);

  if (!FLOAT_TYPE_P (subt))
    return exp;

  if (TYPE_PRECISION (subt) > TYPE_PRECISION (expt))
    return exp;

  return strip_float_extensions (sub);
}


/* Convert EXPR to some floating-point type TYPE.

   EXPR must be float, integer, or enumeral;
   in other cases error is called.  */

tree
convert_to_real (type, expr)
     tree type, expr;
{
  enum built_in_function fcode = builtin_mathfn_code (expr);
  tree itype = TREE_TYPE (expr);

  /* Disable until we figure out how to decide whether the functions are
     present in runtime.  */
  /* Convert (float)sqrt((double)x) where x is float into sqrtf(x) */
  if (optimize
      && (fcode == BUILT_IN_SQRT
	  || fcode == BUILT_IN_SQRTL
	  || fcode == BUILT_IN_SIN
	  || fcode == BUILT_IN_SINL
	  || fcode == BUILT_IN_COS
	  || fcode == BUILT_IN_COSL
	  || fcode == BUILT_IN_EXP
	  || fcode == BUILT_IN_EXPL
	  || fcode == BUILT_IN_LOG
	  || fcode == BUILT_IN_LOGL)
      && (TYPE_MODE (type) == TYPE_MODE (double_type_node)
          || TYPE_MODE (type) == TYPE_MODE (float_type_node)))
    {
      tree arg0 = strip_float_extensions (TREE_VALUE (TREE_OPERAND (expr, 1)));
      tree newtype = type;

      /* We have (outertype)sqrt((innertype)x).  Choose the wider mode from
	 the both as the safe type for operation.  */
      if (TYPE_PRECISION (TREE_TYPE (arg0)) > TYPE_PRECISION (type))
	newtype = TREE_TYPE (arg0);

      /* Be curefull about integer to fp conversions.
	 These may overflow still.  */
      if (FLOAT_TYPE_P (TREE_TYPE (arg0))
	  && TYPE_PRECISION (newtype) < TYPE_PRECISION (itype)
	  && (TYPE_MODE (newtype) == TYPE_MODE (double_type_node)
	      || TYPE_MODE (newtype) == TYPE_MODE (float_type_node)))
	{
	  tree arglist;
	  tree fn = mathfn_built_in (newtype, fcode);

	  if (fn)
	    {
	      arglist = build_tree_list (NULL_TREE, fold (convert_to_real (newtype, arg0)));
	      expr = build_function_call_expr (fn, arglist);
	      if (newtype == type)
		return expr;
	    }
	}
    }
  if (optimize
      && (((fcode == BUILT_IN_FLOORL
	   || fcode == BUILT_IN_CEILL
	   || fcode == BUILT_IN_ROUND
	   || fcode == BUILT_IN_TRUNC
	   || fcode == BUILT_IN_NEARBYINT)
	  && (TYPE_MODE (type) == TYPE_MODE (double_type_node)
	      || TYPE_MODE (type) == TYPE_MODE (float_type_node)))
	  || ((fcode == BUILT_IN_FLOOR
	       || fcode == BUILT_IN_CEIL
	       || fcode == BUILT_IN_ROUND
	       || fcode == BUILT_IN_TRUNC
	       || fcode == BUILT_IN_NEARBYINT)
	      && (TYPE_MODE (type) == TYPE_MODE (float_type_node)))))
    {
      tree fn = mathfn_built_in (type, fcode);

      if (fn)
	{
	  tree arg0 = strip_float_extensions (TREE_VALUE (TREE_OPERAND (expr,
					  				1)));
	  tree arglist = build_tree_list (NULL_TREE,
			  		  fold (convert_to_real (type, arg0)));

	  return build_function_call_expr (fn, arglist);
	}
    }

  /* Propagate the cast into the operation.  */
  if (itype != type && FLOAT_TYPE_P (type))
    switch (TREE_CODE (expr))
      {
	/* convert (float)-x into -(float)x.  This is always safe.  */
	case ABS_EXPR:
	case NEGATE_EXPR:
	  if (TYPE_PRECISION (type) < TYPE_PRECISION (TREE_TYPE (expr)))
	    return build1 (TREE_CODE (expr), type,
			   fold (convert_to_real (type,
						  TREE_OPERAND (expr, 0))));
	  break;
	/* convert (outertype)((innertype0)a+(innertype1)b)
	   into ((newtype)a+(newtype)b) where newtype
	   is the widest mode from all of these.  */
	case PLUS_EXPR:
	case MINUS_EXPR:
	case MULT_EXPR:
	case RDIV_EXPR:
	   {
	     tree arg0 = strip_float_extensions (TREE_OPERAND (expr, 0));
	     tree arg1 = strip_float_extensions (TREE_OPERAND (expr, 1));

	     if (FLOAT_TYPE_P (TREE_TYPE (arg0))
		 && FLOAT_TYPE_P (TREE_TYPE (arg1)))
	       {
		  tree newtype = type;
		  if (TYPE_PRECISION (TREE_TYPE (arg0)) > TYPE_PRECISION (newtype))
		    newtype = TREE_TYPE (arg0);
		  if (TYPE_PRECISION (TREE_TYPE (arg1)) > TYPE_PRECISION (newtype))
		    newtype = TREE_TYPE (arg1);
		  if (TYPE_PRECISION (newtype) < TYPE_PRECISION (itype))
		    {
		      expr = build (TREE_CODE (expr), newtype,
				    fold (convert_to_real (newtype, arg0)),
				    fold (convert_to_real (newtype, arg1)));
		      if (newtype == type)
			return expr;
		    }
	       }
	   }
	  break;
	default:
	  break;
      }

  switch (TREE_CODE (TREE_TYPE (expr)))
    {
    case REAL_TYPE:
      return build1 (flag_float_store ? CONVERT_EXPR : NOP_EXPR,
		     type, expr);

    case INTEGER_TYPE:
    case ENUMERAL_TYPE:
    case BOOLEAN_TYPE:
    case CHAR_TYPE:
      return build1 (FLOAT_EXPR, type, expr);

    case COMPLEX_TYPE:
      return convert (type,
		      fold (build1 (REALPART_EXPR,
				    TREE_TYPE (TREE_TYPE (expr)), expr)));

    case POINTER_TYPE:
    case REFERENCE_TYPE:
      error ("pointer value used where a floating point value was expected");
      return convert_to_real (type, integer_zero_node);

    default:
      error ("aggregate value used where a float was expected");
      return convert_to_real (type, integer_zero_node);
    }
}

/* Convert EXPR to some integer (or enum) type TYPE.

   EXPR must be pointer, integer, discrete (enum, char, or bool), float, or
   vector; in other cases error is called.

   The result of this is always supposed to be a newly created tree node
   not in use in any existing structure.  */

tree
convert_to_integer (type, expr)
     tree type, expr;
{
  enum tree_code ex_form = TREE_CODE (expr);
  tree intype = TREE_TYPE (expr);
  unsigned int inprec = TYPE_PRECISION (intype);
  unsigned int outprec = TYPE_PRECISION (type);

  /* An INTEGER_TYPE cannot be incomplete, but an ENUMERAL_TYPE can
     be.  Consider `enum E = { a, b = (enum E) 3 };'.  */
  if (!COMPLETE_TYPE_P (type))
    {
      error ("conversion to incomplete type");
      return error_mark_node;
    }

  switch (TREE_CODE (intype))
    {
    case POINTER_TYPE:
    case REFERENCE_TYPE:
      if (integer_zerop (expr))
	expr = integer_zero_node;
      else
	expr = fold (build1 (CONVERT_EXPR, (*lang_hooks.types.type_for_size)
			     (POINTER_SIZE, 0), expr));

      return convert_to_integer (type, expr);

    case INTEGER_TYPE:
    case ENUMERAL_TYPE:
    case BOOLEAN_TYPE:
    case CHAR_TYPE:
      /* If this is a logical operation, which just returns 0 or 1, we can
	 change the type of the expression.  For some logical operations,
	 we must also change the types of the operands to maintain type
	 correctness.  */

      if (TREE_CODE_CLASS (ex_form) == '<')
	{
	  TREE_TYPE (expr) = type;
	  return expr;
	}

      else if (ex_form == TRUTH_AND_EXPR || ex_form == TRUTH_ANDIF_EXPR
	       || ex_form == TRUTH_OR_EXPR || ex_form == TRUTH_ORIF_EXPR
	       || ex_form == TRUTH_XOR_EXPR)
	{
	  TREE_OPERAND (expr, 0) = convert (type, TREE_OPERAND (expr, 0));
	  TREE_OPERAND (expr, 1) = convert (type, TREE_OPERAND (expr, 1));
	  TREE_TYPE (expr) = type;
	  return expr;
	}

      else if (ex_form == TRUTH_NOT_EXPR)
	{
	  TREE_OPERAND (expr, 0) = convert (type, TREE_OPERAND (expr, 0));
	  TREE_TYPE (expr) = type;
	  return expr;
	}

      /* If we are widening the type, put in an explicit conversion.
	 Similarly if we are not changing the width.  After this, we know
	 we are truncating EXPR.  */

      else if (outprec >= inprec)
	return build1 (NOP_EXPR, type, expr);

      /* If TYPE is an enumeral type or a type with a precision less
	 than the number of bits in its mode, do the conversion to the
	 type corresponding to its mode, then do a nop conversion
	 to TYPE.  */
      else if (TREE_CODE (type) == ENUMERAL_TYPE
	       || outprec != GET_MODE_BITSIZE (TYPE_MODE (type)))
	return build1 (NOP_EXPR, type,
		       convert ((*lang_hooks.types.type_for_mode)
				(TYPE_MODE (type), TREE_UNSIGNED (type)),
				expr));

      /* Here detect when we can distribute the truncation down past some
	 arithmetic.  For example, if adding two longs and converting to an
	 int, we can equally well convert both to ints and then add.
	 For the operations handled here, such truncation distribution
	 is always safe.
	 It is desirable in these cases:
	 1) when truncating down to full-word from a larger size
	 2) when truncating takes no work.
	 3) when at least one operand of the arithmetic has been extended
	 (as by C's default conversions).  In this case we need two conversions
	 if we do the arithmetic as already requested, so we might as well
	 truncate both and then combine.  Perhaps that way we need only one.

	 Note that in general we cannot do the arithmetic in a type
	 shorter than the desired result of conversion, even if the operands
	 are both extended from a shorter type, because they might overflow
	 if combined in that type.  The exceptions to this--the times when
	 two narrow values can be combined in their narrow type even to
	 make a wider result--are handled by "shorten" in build_binary_op.  */

      switch (ex_form)
	{
	case RSHIFT_EXPR:
	  /* We can pass truncation down through right shifting
	     when the shift count is a nonpositive constant.  */
	  if (TREE_CODE (TREE_OPERAND (expr, 1)) == INTEGER_CST
	      && tree_int_cst_lt (TREE_OPERAND (expr, 1),
				  convert (TREE_TYPE (TREE_OPERAND (expr, 1)),
					   integer_one_node)))
	    goto trunc1;
	  break;

	case LSHIFT_EXPR:
	  /* We can pass truncation down through left shifting
	     when the shift count is a nonnegative constant and
	     the target type is unsigned.  */
	  if (TREE_CODE (TREE_OPERAND (expr, 1)) == INTEGER_CST
	      && tree_int_cst_sgn (TREE_OPERAND (expr, 1)) >= 0
	      && TREE_UNSIGNED (type)
	      && TREE_CODE (TYPE_SIZE (type)) == INTEGER_CST)
	    {
	      /* If shift count is less than the width of the truncated type,
		 really shift.  */
	      if (tree_int_cst_lt (TREE_OPERAND (expr, 1), TYPE_SIZE (type)))
		/* In this case, shifting is like multiplication.  */
		goto trunc1;
	      else
		{
		  /* If it is >= that width, result is zero.
		     Handling this with trunc1 would give the wrong result:
		     (int) ((long long) a << 32) is well defined (as 0)
		     but (int) a << 32 is undefined and would get a
		     warning.  */

		  tree t = convert_to_integer (type, integer_zero_node);

		  /* If the original expression had side-effects, we must
		     preserve it.  */
		  if (TREE_SIDE_EFFECTS (expr))
		    return build (COMPOUND_EXPR, type, expr, t);
		  else
		    return t;
		}
	    }
	  break;

	case MAX_EXPR:
	case MIN_EXPR:
	case MULT_EXPR:
	  {
	    tree arg0 = get_unwidened (TREE_OPERAND (expr, 0), type);
	    tree arg1 = get_unwidened (TREE_OPERAND (expr, 1), type);

	    /* Don't distribute unless the output precision is at least as big
	       as the actual inputs.  Otherwise, the comparison of the
	       truncated values will be wrong.  */
	    if (outprec >= TYPE_PRECISION (TREE_TYPE (arg0))
		&& outprec >= TYPE_PRECISION (TREE_TYPE (arg1))
		/* If signedness of arg0 and arg1 don't match,
		   we can't necessarily find a type to compare them in.  */
		&& (TREE_UNSIGNED (TREE_TYPE (arg0))
		    == TREE_UNSIGNED (TREE_TYPE (arg1))))
	      goto trunc1;
	    break;
	  }

	case PLUS_EXPR:
	case MINUS_EXPR:
	case BIT_AND_EXPR:
	case BIT_IOR_EXPR:
	case BIT_XOR_EXPR:
	case BIT_ANDTC_EXPR:
	trunc1:
	  {
	    tree arg0 = get_unwidened (TREE_OPERAND (expr, 0), type);
	    tree arg1 = get_unwidened (TREE_OPERAND (expr, 1), type);

	    if (outprec >= BITS_PER_WORD
		|| TRULY_NOOP_TRUNCATION (outprec, inprec)
		|| inprec > TYPE_PRECISION (TREE_TYPE (arg0))
		|| inprec > TYPE_PRECISION (TREE_TYPE (arg1)))
	      {
		/* Do the arithmetic in type TYPEX,
		   then convert result to TYPE.  */
		tree typex = type;

		/* Can't do arithmetic in enumeral types
		   so use an integer type that will hold the values.  */
		if (TREE_CODE (typex) == ENUMERAL_TYPE)
		  typex = (*lang_hooks.types.type_for_size)
		    (TYPE_PRECISION (typex), TREE_UNSIGNED (typex));

		/* But now perhaps TYPEX is as wide as INPREC.
		   In that case, do nothing special here.
		   (Otherwise would recurse infinitely in convert.  */
		if (TYPE_PRECISION (typex) != inprec)
		  {
		    /* Don't do unsigned arithmetic where signed was wanted,
		       or vice versa.
		       Exception: if both of the original operands were
 		       unsigned then we can safely do the work as unsigned.
		       Exception: shift operations take their type solely
		       from the first argument.
		       Exception: the LSHIFT_EXPR case above requires that
		       we perform this operation unsigned lest we produce
		       signed-overflow undefinedness.
		       And we may need to do it as unsigned
		       if we truncate to the original size.  */
		    if (TREE_UNSIGNED (TREE_TYPE (expr))
			|| (TREE_UNSIGNED (TREE_TYPE (arg0))
			    && (TREE_UNSIGNED (TREE_TYPE (arg1))
				|| ex_form == LSHIFT_EXPR
				|| ex_form == RSHIFT_EXPR
				|| ex_form == LROTATE_EXPR
				|| ex_form == RROTATE_EXPR))
			|| ex_form == LSHIFT_EXPR)
		      typex = (*lang_hooks.types.unsigned_type) (typex);
		    else
		      typex = (*lang_hooks.types.signed_type) (typex);
		    return convert (type,
				    fold (build (ex_form, typex,
						 convert (typex, arg0),
						 convert (typex, arg1),
						 0)));
		  }
	      }
	  }
	  break;

	case NEGATE_EXPR:
	case BIT_NOT_EXPR:
	  /* This is not correct for ABS_EXPR,
	     since we must test the sign before truncation.  */
	  {
	    tree typex = type;

	    /* Can't do arithmetic in enumeral types
	       so use an integer type that will hold the values.  */
	    if (TREE_CODE (typex) == ENUMERAL_TYPE)
	      typex = (*lang_hooks.types.type_for_size)
		(TYPE_PRECISION (typex), TREE_UNSIGNED (typex));

	    /* But now perhaps TYPEX is as wide as INPREC.
	       In that case, do nothing special here.
	       (Otherwise would recurse infinitely in convert.  */
	    if (TYPE_PRECISION (typex) != inprec)
	      {
		/* Don't do unsigned arithmetic where signed was wanted,
		   or vice versa.  */
		if (TREE_UNSIGNED (TREE_TYPE (expr)))
		  typex = (*lang_hooks.types.unsigned_type) (typex);
		else
		  typex = (*lang_hooks.types.signed_type) (typex);
		return convert (type,
				fold (build1 (ex_form, typex,
					      convert (typex,
						       TREE_OPERAND (expr, 0)))));
	      }
	  }

	case NOP_EXPR:
	  /* Don't introduce a
	     "can't convert between vector values of different size" error.  */
	  if (TREE_CODE (TREE_TYPE (TREE_OPERAND (expr, 0))) == VECTOR_TYPE
	      && (GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (TREE_OPERAND (expr, 0))))
		  != GET_MODE_SIZE (TYPE_MODE (type))))
	    break;
	  /* If truncating after truncating, might as well do all at once.
	     If truncating after extending, we may get rid of wasted work.  */
	  return convert (type, get_unwidened (TREE_OPERAND (expr, 0), type));

	case COND_EXPR:
	  /* It is sometimes worthwhile to push the narrowing down through
	     the conditional and never loses.  */
	  return fold (build (COND_EXPR, type, TREE_OPERAND (expr, 0),
			      convert (type, TREE_OPERAND (expr, 1)), 
			      convert (type, TREE_OPERAND (expr, 2))));

	default:
	  break;
	}

      return build1 (NOP_EXPR, type, expr);

    case REAL_TYPE:
      return build1 (FIX_TRUNC_EXPR, type, expr);

    case COMPLEX_TYPE:
      return convert (type,
		      fold (build1 (REALPART_EXPR,
				    TREE_TYPE (TREE_TYPE (expr)), expr)));

    case VECTOR_TYPE:
      if (GET_MODE_SIZE (TYPE_MODE (type))
	  != GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (expr))))
	{
	  error ("can't convert between vector values of different size");
	  return error_mark_node;
	}
      return build1 (NOP_EXPR, type, expr);

    default:
      error ("aggregate value used where an integer was expected");
      return convert (type, integer_zero_node);
    }
}

/* Convert EXPR to the complex type TYPE in the usual ways.  */

tree
convert_to_complex (type, expr)
     tree type, expr;
{
  tree subtype = TREE_TYPE (type);
  
  switch (TREE_CODE (TREE_TYPE (expr)))
    {
    case REAL_TYPE:
    case INTEGER_TYPE:
    case ENUMERAL_TYPE:
    case BOOLEAN_TYPE:
    case CHAR_TYPE:
      return build (COMPLEX_EXPR, type, convert (subtype, expr),
		    convert (subtype, integer_zero_node));

    case COMPLEX_TYPE:
      {
	tree elt_type = TREE_TYPE (TREE_TYPE (expr));

	if (TYPE_MAIN_VARIANT (elt_type) == TYPE_MAIN_VARIANT (subtype))
	  return expr;
	else if (TREE_CODE (expr) == COMPLEX_EXPR)
	  return fold (build (COMPLEX_EXPR,
			      type,
			      convert (subtype, TREE_OPERAND (expr, 0)),
			      convert (subtype, TREE_OPERAND (expr, 1))));
	else
	  {
	    expr = save_expr (expr);
	    return
	      fold (build (COMPLEX_EXPR,
			   type, convert (subtype,
					  fold (build1 (REALPART_EXPR,
							TREE_TYPE (TREE_TYPE (expr)),
							expr))),
			   convert (subtype,
				    fold (build1 (IMAGPART_EXPR,
						  TREE_TYPE (TREE_TYPE (expr)),
						  expr)))));
	  }
      }

    case POINTER_TYPE:
    case REFERENCE_TYPE:
      error ("pointer value used where a complex was expected");
      return convert_to_complex (type, integer_zero_node);

    default:
      error ("aggregate value used where a complex was expected");
      return convert_to_complex (type, integer_zero_node);
    }
}

/* Convert EXPR to the vector type TYPE in the usual ways.  */

tree
convert_to_vector (type, expr)
     tree type, expr;
{
  switch (TREE_CODE (TREE_TYPE (expr)))
    {
    case INTEGER_TYPE:
    case VECTOR_TYPE:
      if (GET_MODE_SIZE (TYPE_MODE (type))
	  != GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (expr))))
	{
	  error ("can't convert between vector values of different size");
	  return error_mark_node;
	}
      return build1 (NOP_EXPR, type, expr);

    default:
      error ("can't convert value to a vector");
      return convert_to_vector (type, integer_zero_node);
    }
}