diff options
Diffstat (limited to 'gcc/tree-chrec.c')
| -rw-r--r-- | gcc/tree-chrec.c | 33 |
1 files changed, 31 insertions, 2 deletions
diff --git a/gcc/tree-chrec.c b/gcc/tree-chrec.c index 30915d2..b1587a5 100644 --- a/gcc/tree-chrec.c +++ b/gcc/tree-chrec.c @@ -1,6 +1,6 @@ /* Chains of recurrences. - Copyright (C) 2003, 2004, 2005 Free Software Foundation, Inc. - Contributed by Sebastian Pop <s.pop@laposte.net> + Copyright (C) 2003, 2004, 2005, 2006 Free Software Foundation, Inc. + Contributed by Sebastian Pop <pop@cri.ensmp.fr> This file is part of GCC. @@ -1232,3 +1232,32 @@ chrec_type (tree chrec) return TREE_TYPE (chrec); } + +/* Returns true when CHREC0 == CHREC1. */ + +bool +eq_evolutions_p (tree chrec0, + tree chrec1) +{ + if (chrec0 == NULL_TREE + || chrec1 == NULL_TREE + || TREE_CODE (chrec0) != TREE_CODE (chrec1)) + return false; + + if (chrec0 == chrec1) + return true; + + switch (TREE_CODE (chrec0)) + { + case INTEGER_CST: + return integer_zerop (fold (build2 (MINUS_EXPR, TREE_TYPE (chrec0), + chrec0, chrec1))); + case POLYNOMIAL_CHREC: + return (CHREC_VARIABLE (chrec0) == CHREC_VARIABLE (chrec1) + && eq_evolutions_p (CHREC_LEFT (chrec0), CHREC_LEFT (chrec1)) + && eq_evolutions_p (CHREC_RIGHT (chrec0), CHREC_RIGHT (chrec1))); + default: + return false; + } +} + |