1 /* Chains of recurrences.
2 Copyright (C) 2003, 2004 Free Software Foundation, Inc.
3 Contributed by Sebastian Pop <s.pop@laposte.net>
5 This file is part of GCC.
7 GCC is free software; you can redistribute it and/or modify it under
8 the terms of the GNU General Public License as published by the Free
9 Software Foundation; either version 2, or (at your option) any later
12 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
13 WARRANTY; without even the implied warranty of MERCHANTABILITY or
14 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
17 You should have received a copy of the GNU General Public License
18 along with GCC; see the file COPYING. If not, write to the Free
19 Software Foundation, 59 Temple Place - Suite 330, Boston, MA
22 /* This file implements operations on chains of recurrences. Chains
23 of recurrences are used for modeling evolution functions of scalar
29 #include "coretypes.h"
34 #include "diagnostic.h"
36 #include "tree-chrec.h"
37 #include "tree-pass.h"
41 /* Extended folder for chrecs. */
43 /* Determines whether CST is not a constant evolution. */
46 is_not_constant_evolution (tree cst)
48 return (TREE_CODE (cst) == POLYNOMIAL_CHREC);
51 /* Fold CODE for a polynomial function and a constant. */
54 chrec_fold_poly_cst (enum tree_code code,
61 gcc_assert (TREE_CODE (poly) == POLYNOMIAL_CHREC);
62 gcc_assert (!is_not_constant_evolution (cst));
67 return build_polynomial_chrec
68 (CHREC_VARIABLE (poly),
69 chrec_fold_plus (type, CHREC_LEFT (poly), cst),
73 return build_polynomial_chrec
74 (CHREC_VARIABLE (poly),
75 chrec_fold_minus (type, CHREC_LEFT (poly), cst),
79 return build_polynomial_chrec
80 (CHREC_VARIABLE (poly),
81 chrec_fold_multiply (type, CHREC_LEFT (poly), cst),
82 chrec_fold_multiply (type, CHREC_RIGHT (poly), cst));
85 return chrec_dont_know;
89 /* Fold the addition of two polynomial functions. */
92 chrec_fold_plus_poly_poly (enum tree_code code,
101 gcc_assert (TREE_CODE (poly0) == POLYNOMIAL_CHREC);
102 gcc_assert (TREE_CODE (poly1) == POLYNOMIAL_CHREC);
105 {a, +, b}_1 + {c, +, d}_2 -> {{a, +, b}_1 + c, +, d}_2,
106 {a, +, b}_2 + {c, +, d}_1 -> {{c, +, d}_1 + a, +, b}_2,
107 {a, +, b}_x + {c, +, d}_x -> {a+c, +, b+d}_x. */
108 if (CHREC_VARIABLE (poly0) < CHREC_VARIABLE (poly1))
110 if (code == PLUS_EXPR)
111 return build_polynomial_chrec
112 (CHREC_VARIABLE (poly1),
113 chrec_fold_plus (type, poly0, CHREC_LEFT (poly1)),
114 CHREC_RIGHT (poly1));
116 return build_polynomial_chrec
117 (CHREC_VARIABLE (poly1),
118 chrec_fold_minus (type, poly0, CHREC_LEFT (poly1)),
119 chrec_fold_multiply (type, CHREC_RIGHT (poly1),
120 convert (type, integer_minus_one_node)));
123 if (CHREC_VARIABLE (poly0) > CHREC_VARIABLE (poly1))
125 if (code == PLUS_EXPR)
126 return build_polynomial_chrec
127 (CHREC_VARIABLE (poly0),
128 chrec_fold_plus (type, CHREC_LEFT (poly0), poly1),
129 CHREC_RIGHT (poly0));
131 return build_polynomial_chrec
132 (CHREC_VARIABLE (poly0),
133 chrec_fold_minus (type, CHREC_LEFT (poly0), poly1),
134 CHREC_RIGHT (poly0));
137 if (code == PLUS_EXPR)
139 left = chrec_fold_plus
140 (type, CHREC_LEFT (poly0), CHREC_LEFT (poly1));
141 right = chrec_fold_plus
142 (type, CHREC_RIGHT (poly0), CHREC_RIGHT (poly1));
146 left = chrec_fold_minus
147 (type, CHREC_LEFT (poly0), CHREC_LEFT (poly1));
148 right = chrec_fold_minus
149 (type, CHREC_RIGHT (poly0), CHREC_RIGHT (poly1));
152 if (chrec_zerop (right))
155 return build_polynomial_chrec
156 (CHREC_VARIABLE (poly0), left, right);
161 /* Fold the multiplication of two polynomial functions. */
164 chrec_fold_multiply_poly_poly (tree type,
170 gcc_assert (TREE_CODE (poly0) == POLYNOMIAL_CHREC);
171 gcc_assert (TREE_CODE (poly1) == POLYNOMIAL_CHREC);
173 /* {a, +, b}_1 * {c, +, d}_2 -> {c*{a, +, b}_1, +, d}_2,
174 {a, +, b}_2 * {c, +, d}_1 -> {a*{c, +, d}_1, +, b}_2,
175 {a, +, b}_x * {c, +, d}_x -> {a*c, +, a*d + b*c + b*d, +, 2*b*d}_x. */
176 if (CHREC_VARIABLE (poly0) < CHREC_VARIABLE (poly1))
177 /* poly0 is a constant wrt. poly1. */
178 return build_polynomial_chrec
179 (CHREC_VARIABLE (poly1),
180 chrec_fold_multiply (type, CHREC_LEFT (poly1), poly0),
181 CHREC_RIGHT (poly1));
183 if (CHREC_VARIABLE (poly1) < CHREC_VARIABLE (poly0))
184 /* poly1 is a constant wrt. poly0. */
185 return build_polynomial_chrec
186 (CHREC_VARIABLE (poly0),
187 chrec_fold_multiply (type, CHREC_LEFT (poly0), poly1),
188 CHREC_RIGHT (poly0));
190 /* poly0 and poly1 are two polynomials in the same variable,
191 {a, +, b}_x * {c, +, d}_x -> {a*c, +, a*d + b*c + b*d, +, 2*b*d}_x. */
193 build_polynomial_chrec
194 (CHREC_VARIABLE (poly0),
195 build_polynomial_chrec
196 (CHREC_VARIABLE (poly0),
199 chrec_fold_multiply (type, CHREC_LEFT (poly0), CHREC_LEFT (poly1)),
201 /* "a*d + b*c + b*d". */
203 (type, chrec_fold_multiply (type, CHREC_LEFT (poly0), CHREC_RIGHT (poly1)),
207 chrec_fold_multiply (type, CHREC_RIGHT (poly0), CHREC_LEFT (poly1)),
208 chrec_fold_multiply (type, CHREC_RIGHT (poly0), CHREC_RIGHT (poly1))))),
212 (type, build_int_cst (NULL_TREE, 2),
213 chrec_fold_multiply (type, CHREC_RIGHT (poly0), CHREC_RIGHT (poly1))));
216 /* When the operands are automatically_generated_chrec_p, the fold has
217 to respect the semantics of the operands. */
220 chrec_fold_automatically_generated_operands (tree op0,
223 if (op0 == chrec_dont_know
224 || op1 == chrec_dont_know)
225 return chrec_dont_know;
227 if (op0 == chrec_known
228 || op1 == chrec_known)
231 if (op0 == chrec_not_analyzed_yet
232 || op1 == chrec_not_analyzed_yet)
233 return chrec_not_analyzed_yet;
235 /* The default case produces a safe result. */
236 return chrec_dont_know;
239 /* Fold the addition of two chrecs. */
242 chrec_fold_plus_1 (enum tree_code code,
247 if (automatically_generated_chrec_p (op0)
248 || automatically_generated_chrec_p (op1))
249 return chrec_fold_automatically_generated_operands (op0, op1);
251 switch (TREE_CODE (op0))
253 case POLYNOMIAL_CHREC:
254 switch (TREE_CODE (op1))
256 case POLYNOMIAL_CHREC:
257 return chrec_fold_plus_poly_poly (code, type, op0, op1);
260 if (code == PLUS_EXPR)
261 return build_polynomial_chrec
262 (CHREC_VARIABLE (op0),
263 chrec_fold_plus (type, CHREC_LEFT (op0), op1),
266 return build_polynomial_chrec
267 (CHREC_VARIABLE (op0),
268 chrec_fold_minus (type, CHREC_LEFT (op0), op1),
273 switch (TREE_CODE (op1))
275 case POLYNOMIAL_CHREC:
276 if (code == PLUS_EXPR)
277 return build_polynomial_chrec
278 (CHREC_VARIABLE (op1),
279 chrec_fold_plus (type, op0, CHREC_LEFT (op1)),
282 return build_polynomial_chrec
283 (CHREC_VARIABLE (op1),
284 chrec_fold_minus (type, op0, CHREC_LEFT (op1)),
285 chrec_fold_multiply (type, CHREC_RIGHT (op1),
287 integer_minus_one_node)));
290 if (tree_contains_chrecs (op0)
291 || tree_contains_chrecs (op1))
292 return build (code, type, op0, op1);
294 return fold (build (code, type, op0, op1));
299 /* Fold the addition of two chrecs. */
302 chrec_fold_plus (tree type,
306 if (integer_zerop (op0))
308 if (integer_zerop (op1))
311 return chrec_fold_plus_1 (PLUS_EXPR, type, op0, op1);
314 /* Fold the subtraction of two chrecs. */
317 chrec_fold_minus (tree type,
321 if (integer_zerop (op1))
324 return chrec_fold_plus_1 (MINUS_EXPR, type, op0, op1);
327 /* Fold the multiplication of two chrecs. */
330 chrec_fold_multiply (tree type,
334 if (automatically_generated_chrec_p (op0)
335 || automatically_generated_chrec_p (op1))
336 return chrec_fold_automatically_generated_operands (op0, op1);
338 switch (TREE_CODE (op0))
340 case POLYNOMIAL_CHREC:
341 switch (TREE_CODE (op1))
343 case POLYNOMIAL_CHREC:
344 return chrec_fold_multiply_poly_poly (type, op0, op1);
347 if (integer_onep (op1))
349 if (integer_zerop (op1))
350 return convert (type, integer_zero_node);
352 return build_polynomial_chrec
353 (CHREC_VARIABLE (op0),
354 chrec_fold_multiply (type, CHREC_LEFT (op0), op1),
355 chrec_fold_multiply (type, CHREC_RIGHT (op0), op1));
359 if (integer_onep (op0))
362 if (integer_zerop (op0))
363 return convert (type, integer_zero_node);
365 switch (TREE_CODE (op1))
367 case POLYNOMIAL_CHREC:
368 return build_polynomial_chrec
369 (CHREC_VARIABLE (op1),
370 chrec_fold_multiply (type, CHREC_LEFT (op1), op0),
371 chrec_fold_multiply (type, CHREC_RIGHT (op1), op0));
374 if (integer_onep (op1))
376 if (integer_zerop (op1))
377 return convert (type, integer_zero_node);
378 return fold (build (MULT_EXPR, type, op0, op1));
390 tree_fold_factorial (tree f)
392 if (tree_int_cst_sgn (f) <= 0)
393 return integer_one_node;
396 (build (MULT_EXPR, integer_type_node, f,
397 tree_fold_factorial (fold (build (MINUS_EXPR, integer_type_node,
398 f, integer_one_node)))));
401 /* The binomial coefficient. */
404 tree_fold_binomial (tree n,
408 (build (EXACT_DIV_EXPR, integer_type_node, tree_fold_factorial (n),
409 fold (build (MULT_EXPR, integer_type_node,
410 tree_fold_factorial (k),
412 (fold (build (MINUS_EXPR, integer_type_node,
416 /* Helper function. Use the Newton's interpolating formula for
417 evaluating the value of the evolution function. */
420 chrec_evaluate (unsigned var,
425 tree type = chrec_type (chrec);
426 tree binomial_n_k = tree_fold_binomial (n, k);
428 if (TREE_CODE (chrec) == POLYNOMIAL_CHREC)
430 if (CHREC_VARIABLE (chrec) > var)
431 return chrec_evaluate (var, CHREC_LEFT (chrec), n, k);
433 if (CHREC_VARIABLE (chrec) == var)
434 return chrec_fold_plus
436 fold (build (MULT_EXPR, type, binomial_n_k, CHREC_LEFT (chrec))),
437 chrec_evaluate (var, CHREC_RIGHT (chrec), n,
438 fold (build (PLUS_EXPR, type, k, integer_one_node))));
440 return fold (build (MULT_EXPR, type, binomial_n_k, chrec));
443 return fold (build (MULT_EXPR, type, binomial_n_k, chrec));
446 /* Evaluates "CHREC (X)" when the varying variable is VAR.
447 Example: Given the following parameters,
453 The result is given by the Newton's interpolating formula:
454 3 * \binom{10}{0} + 4 * \binom{10}{1}.
458 chrec_apply (unsigned var,
462 tree type = chrec_type (chrec);
463 tree res = chrec_dont_know;
465 if (automatically_generated_chrec_p (chrec)
466 || automatically_generated_chrec_p (x)
468 /* When the symbols are defined in an outer loop, it is possible
469 to symbolically compute the apply, since the symbols are
470 constants with respect to the varying loop. */
471 || chrec_contains_symbols_defined_in_loop (chrec, var)
472 || chrec_contains_symbols (x))
473 return chrec_dont_know;
475 if (dump_file && (dump_flags & TDF_DETAILS))
476 fprintf (dump_file, "(chrec_apply \n");
478 if (evolution_function_is_affine_p (chrec))
480 /* "{a, +, b} (x)" -> "a + b*x". */
481 if (TREE_CODE (CHREC_LEFT (chrec)) == INTEGER_CST
482 && integer_zerop (CHREC_LEFT (chrec)))
483 res = chrec_fold_multiply (type, CHREC_RIGHT (chrec), x);
486 res = chrec_fold_plus (type, CHREC_LEFT (chrec),
487 chrec_fold_multiply (type,
488 CHREC_RIGHT (chrec), x));
491 else if (TREE_CODE (chrec) != POLYNOMIAL_CHREC)
494 else if (TREE_CODE (x) == INTEGER_CST
495 && tree_int_cst_sgn (x) == 1)
496 /* testsuite/.../ssa-chrec-38.c. */
497 res = chrec_evaluate (var, chrec, x, integer_zero_node);
500 res = chrec_dont_know;
502 if (dump_file && (dump_flags & TDF_DETAILS))
504 fprintf (dump_file, " (varying_loop = %d\n", var);
505 fprintf (dump_file, ")\n (chrec = ");
506 print_generic_expr (dump_file, chrec, 0);
507 fprintf (dump_file, ")\n (x = ");
508 print_generic_expr (dump_file, x, 0);
509 fprintf (dump_file, ")\n (res = ");
510 print_generic_expr (dump_file, res, 0);
511 fprintf (dump_file, "))\n");
517 /* Replaces the initial condition in CHREC with INIT_COND. */
520 chrec_replace_initial_condition (tree chrec,
523 if (automatically_generated_chrec_p (chrec))
526 switch (TREE_CODE (chrec))
528 case POLYNOMIAL_CHREC:
529 return build_polynomial_chrec
530 (CHREC_VARIABLE (chrec),
531 chrec_replace_initial_condition (CHREC_LEFT (chrec), init_cond),
532 CHREC_RIGHT (chrec));
539 /* Returns the initial condition of a given CHREC. */
542 initial_condition (tree chrec)
544 if (automatically_generated_chrec_p (chrec))
547 if (TREE_CODE (chrec) == POLYNOMIAL_CHREC)
548 return initial_condition (CHREC_LEFT (chrec));
553 /* Returns a univariate function that represents the evolution in
554 LOOP_NUM. Mask the evolution of any other loop. */
557 hide_evolution_in_other_loops_than_loop (tree chrec,
560 if (automatically_generated_chrec_p (chrec))
563 switch (TREE_CODE (chrec))
565 case POLYNOMIAL_CHREC:
566 if (CHREC_VARIABLE (chrec) == loop_num)
567 return build_polynomial_chrec
569 hide_evolution_in_other_loops_than_loop (CHREC_LEFT (chrec),
571 CHREC_RIGHT (chrec));
573 else if (CHREC_VARIABLE (chrec) < loop_num)
574 /* There is no evolution in this loop. */
575 return initial_condition (chrec);
578 return hide_evolution_in_other_loops_than_loop (CHREC_LEFT (chrec),
586 /* Returns the evolution part in LOOP_NUM. Example: the call
587 get_evolution_in_loop (1, {{0, +, 1}_1, +, 2}_1) returns
591 evolution_part_in_loop_num (tree chrec,
594 if (automatically_generated_chrec_p (chrec))
597 switch (TREE_CODE (chrec))
599 case POLYNOMIAL_CHREC:
600 if (CHREC_VARIABLE (chrec) == loop_num)
602 if (TREE_CODE (CHREC_LEFT (chrec)) != POLYNOMIAL_CHREC
603 || CHREC_VARIABLE (CHREC_LEFT (chrec)) != CHREC_VARIABLE (chrec))
604 return CHREC_RIGHT (chrec);
607 return build_polynomial_chrec
609 evolution_part_in_loop_num (CHREC_LEFT (chrec), loop_num),
610 CHREC_RIGHT (chrec));
613 else if (CHREC_VARIABLE (chrec) < loop_num)
614 /* There is no evolution part in this loop. */
618 return evolution_part_in_loop_num (CHREC_LEFT (chrec), loop_num);
625 /* Set or reset the evolution of CHREC to NEW_EVOL in loop LOOP_NUM.
626 This function is essentially used for setting the evolution to
627 chrec_dont_know, for example after having determined that it is
628 impossible to say how many times a loop will execute. */
631 reset_evolution_in_loop (unsigned loop_num,
635 if (TREE_CODE (chrec) == POLYNOMIAL_CHREC
636 && CHREC_VARIABLE (chrec) > loop_num)
639 build_int_cst (NULL_TREE, CHREC_VARIABLE (chrec)),
640 reset_evolution_in_loop (loop_num, CHREC_LEFT (chrec), new_evol),
641 reset_evolution_in_loop (loop_num, CHREC_RIGHT (chrec), new_evol));
643 while (TREE_CODE (chrec) == POLYNOMIAL_CHREC
644 && CHREC_VARIABLE (chrec) == loop_num)
645 chrec = CHREC_LEFT (chrec);
647 return build_polynomial_chrec (loop_num, chrec, new_evol);
650 /* Merges two evolution functions that were found by following two
651 alternate paths of a conditional expression. */
654 chrec_merge (tree chrec1,
657 if (chrec1 == chrec_dont_know
658 || chrec2 == chrec_dont_know)
659 return chrec_dont_know;
661 if (chrec1 == chrec_known
662 || chrec2 == chrec_known)
665 if (chrec1 == chrec_not_analyzed_yet)
667 if (chrec2 == chrec_not_analyzed_yet)
670 if (operand_equal_p (chrec1, chrec2, 0))
673 return chrec_dont_know;
680 /* Helper function for is_multivariate_chrec. */
683 is_multivariate_chrec_rec (tree chrec, unsigned int rec_var)
685 if (chrec == NULL_TREE)
688 if (TREE_CODE (chrec) == POLYNOMIAL_CHREC)
690 if (CHREC_VARIABLE (chrec) != rec_var)
693 return (is_multivariate_chrec_rec (CHREC_LEFT (chrec), rec_var)
694 || is_multivariate_chrec_rec (CHREC_RIGHT (chrec), rec_var));
700 /* Determine whether the given chrec is multivariate or not. */
703 is_multivariate_chrec (tree chrec)
705 if (chrec == NULL_TREE)
708 if (TREE_CODE (chrec) == POLYNOMIAL_CHREC)
709 return (is_multivariate_chrec_rec (CHREC_LEFT (chrec),
710 CHREC_VARIABLE (chrec))
711 || is_multivariate_chrec_rec (CHREC_RIGHT (chrec),
712 CHREC_VARIABLE (chrec)));
717 /* Determines whether the chrec contains symbolic names or not. */
720 chrec_contains_symbols (tree chrec)
722 if (chrec == NULL_TREE)
725 if (TREE_CODE (chrec) == SSA_NAME
726 || TREE_CODE (chrec) == VAR_DECL
727 || TREE_CODE (chrec) == PARM_DECL
728 || TREE_CODE (chrec) == FUNCTION_DECL
729 || TREE_CODE (chrec) == LABEL_DECL
730 || TREE_CODE (chrec) == RESULT_DECL
731 || TREE_CODE (chrec) == FIELD_DECL)
734 switch (TREE_CODE_LENGTH (TREE_CODE (chrec)))
737 if (chrec_contains_symbols (TREE_OPERAND (chrec, 2)))
741 if (chrec_contains_symbols (TREE_OPERAND (chrec, 1)))
745 if (chrec_contains_symbols (TREE_OPERAND (chrec, 0)))
753 /* Determines whether the chrec contains undetermined coefficients. */
756 chrec_contains_undetermined (tree chrec)
758 if (chrec == chrec_dont_know
759 || chrec == chrec_not_analyzed_yet
760 || chrec == NULL_TREE)
763 switch (TREE_CODE_LENGTH (TREE_CODE (chrec)))
766 if (chrec_contains_undetermined (TREE_OPERAND (chrec, 2)))
770 if (chrec_contains_undetermined (TREE_OPERAND (chrec, 1)))
774 if (chrec_contains_undetermined (TREE_OPERAND (chrec, 0)))
782 /* Determines whether the tree EXPR contains chrecs. */
785 tree_contains_chrecs (tree expr)
787 if (expr == NULL_TREE)
790 if (tree_is_chrec (expr))
793 switch (TREE_CODE_LENGTH (TREE_CODE (expr)))
796 if (tree_contains_chrecs (TREE_OPERAND (expr, 2)))
800 if (tree_contains_chrecs (TREE_OPERAND (expr, 1)))
804 if (tree_contains_chrecs (TREE_OPERAND (expr, 0)))
812 /* Determine whether the given tree is an affine multivariate
816 evolution_function_is_affine_multivariate_p (tree chrec)
818 if (chrec == NULL_TREE)
821 switch (TREE_CODE (chrec))
823 case POLYNOMIAL_CHREC:
824 if (evolution_function_is_constant_p (CHREC_LEFT (chrec)))
826 if (evolution_function_is_constant_p (CHREC_RIGHT (chrec)))
830 if (TREE_CODE (CHREC_RIGHT (chrec)) == POLYNOMIAL_CHREC
831 && CHREC_VARIABLE (CHREC_RIGHT (chrec))
832 != CHREC_VARIABLE (chrec)
833 && evolution_function_is_affine_multivariate_p
834 (CHREC_RIGHT (chrec)))
842 if (evolution_function_is_constant_p (CHREC_RIGHT (chrec))
843 && TREE_CODE (CHREC_LEFT (chrec)) == POLYNOMIAL_CHREC
844 && CHREC_VARIABLE (CHREC_LEFT (chrec)) != CHREC_VARIABLE (chrec)
845 && evolution_function_is_affine_multivariate_p
846 (CHREC_LEFT (chrec)))
857 /* Determine whether the given tree is a function in zero or one
861 evolution_function_is_univariate_p (tree chrec)
863 if (chrec == NULL_TREE)
866 switch (TREE_CODE (chrec))
868 case POLYNOMIAL_CHREC:
869 switch (TREE_CODE (CHREC_LEFT (chrec)))
871 case POLYNOMIAL_CHREC:
872 if (CHREC_VARIABLE (chrec) != CHREC_VARIABLE (CHREC_LEFT (chrec)))
874 if (!evolution_function_is_univariate_p (CHREC_LEFT (chrec)))
882 switch (TREE_CODE (CHREC_RIGHT (chrec)))
884 case POLYNOMIAL_CHREC:
885 if (CHREC_VARIABLE (chrec) != CHREC_VARIABLE (CHREC_RIGHT (chrec)))
887 if (!evolution_function_is_univariate_p (CHREC_RIGHT (chrec)))
902 /* Convert the initial condition of chrec to type. */
905 chrec_convert (tree type,
910 if (automatically_generated_chrec_p (chrec))
913 ct = chrec_type (chrec);
917 if (TYPE_PRECISION (ct) < TYPE_PRECISION (type))
918 return count_ev_in_wider_type (type, chrec);
920 switch (TREE_CODE (chrec))
922 case POLYNOMIAL_CHREC:
923 return build_polynomial_chrec (CHREC_VARIABLE (chrec),
927 CHREC_RIGHT (chrec)));
931 tree res = convert (type, chrec);
933 /* Don't propagate overflows. */
934 TREE_OVERFLOW (res) = 0;
935 if (TREE_CODE_CLASS (TREE_CODE (res)) == 'c')
936 TREE_CONSTANT_OVERFLOW (res) = 0;
942 /* Returns the type of the chrec. */
945 chrec_type (tree chrec)
947 if (automatically_generated_chrec_p (chrec))
950 return TREE_TYPE (chrec);
953 extern void initialize_scalar_evolutions_analyzer (void);
958 initialize_scalar_evolutions_analyzer (void)
960 /* The elements below are unique. */
961 if (chrec_dont_know == NULL_TREE)
963 chrec_not_analyzed_yet = NULL_TREE;
964 chrec_dont_know = make_node (SCEV_NOT_KNOWN);
965 chrec_known = make_node (SCEV_KNOWN);
966 TREE_TYPE (chrec_dont_know) = NULL_TREE;
967 TREE_TYPE (chrec_known) = NULL_TREE;