diff options
Diffstat (limited to 'gcc/tree.c')
| -rw-r--r-- | gcc/tree.c | 73 |
1 files changed, 73 insertions, 0 deletions
@@ -3491,6 +3491,79 @@ compare_tree_int (t, u) else return 1; } + +/* Generate a hash value for an expression. This can be used iteratively + by passing a previous result as the "val" argument. + + This function is intended to produce the same hash for expressions which + would compare equal using operand_equal_p. */ + +hashval_t +iterative_hash_expr (tree t, hashval_t val) +{ + int i; + enum tree_code code; + char class; + + if (t == NULL_TREE) + return iterative_hash_object (t, val); + + code = TREE_CODE (t); + class = TREE_CODE_CLASS (code); + + if (class == 'd') + { + /* Decls we can just compare by pointer. */ + val = iterative_hash_object (t, val); + } + else if (class == 'c') + { + /* Alas, constants aren't shared, so we can't rely on pointer + identity. */ + if (code == INTEGER_CST) + { + val = iterative_hash_object (TREE_INT_CST_LOW (t), val); + val = iterative_hash_object (TREE_INT_CST_HIGH (t), val); + } + else if (code == REAL_CST) + val = iterative_hash (TREE_REAL_CST_PTR (t), + sizeof (REAL_VALUE_TYPE), val); + else if (code == STRING_CST) + val = iterative_hash (TREE_STRING_POINTER (t), + TREE_STRING_LENGTH (t), val); + else if (code == COMPLEX_CST) + { + val = iterative_hash_expr (TREE_REALPART (t), val); + val = iterative_hash_expr (TREE_IMAGPART (t), val); + } + else if (code == VECTOR_CST) + val = iterative_hash_expr (TREE_VECTOR_CST_ELTS (t), val); + else + abort (); + } + else if (IS_EXPR_CODE_CLASS (class) || class == 'r') + { + val = iterative_hash_object (code, val); + + if (code == NOP_EXPR || code == CONVERT_EXPR + || code == NON_LVALUE_EXPR) + val = iterative_hash_object (TREE_TYPE (t), val); + + for (i = first_rtl_op (code) - 1; i >= 0; --i) + val = iterative_hash_expr (TREE_OPERAND (t, i), val); + } + else if (code == TREE_LIST) + { + /* A list of expressions, for a CALL_EXPR or as the elements of a + VECTOR_CST. */ + for (; t; t = TREE_CHAIN (t)) + val = iterative_hash_expr (TREE_VALUE (t), val); + } + else + abort (); + + return val; +} /* Constructors for pointer, array and function types. (RECORD_TYPE, UNION_TYPE and ENUMERAL_TYPE nodes are |