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a0b1798042
When folding a multiply CHRECs are handled like {a, +, b} * c
is {a*c, +, b*c} but that isn't generally correct when overflow
invokes undefined behavior. The following uses unsigned arithmetic
unless either a is zero or a and b have the same sign.
I've used simple early outs for INTEGER_CSTs and otherwise use
a range-query since we lack a tree_expr_nonpositive_p and
get_range_pos_neg isn't a good fit.
PR tree-optimization/114074
* tree-chrec.h (chrec_convert_rhs): Default at_stmt arg to NULL.
* tree-chrec.cc (chrec_fold_multiply): Canonicalize inputs.
Handle poly vs. non-poly multiplication correctly with respect
to undefined behavior on overflow.
* gcc.dg/torture/pr114074.c: New testcase.
* gcc.dg/pr68317.c: Adjust expected location of diagnostic.
* gcc.dg/vect/vect-early-break_119-pr114068.c: Do not expect
loop to be vectorized.
254 lines
7.1 KiB
C
254 lines
7.1 KiB
C
/* Chains of recurrences.
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Copyright (C) 2003-2024 Free Software Foundation, Inc.
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Contributed by Sebastian Pop <pop@cri.ensmp.fr>
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This file is part of GCC.
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GCC is free software; you can redistribute it and/or modify it under
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the terms of the GNU General Public License as published by the Free
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Software Foundation; either version 3, or (at your option) any later
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version.
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GCC is distributed in the hope that it will be useful, but WITHOUT ANY
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WARRANTY; without even the implied warranty of MERCHANTABILITY or
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FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
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for more details.
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You should have received a copy of the GNU General Public License
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along with GCC; see the file COPYING3. If not see
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<http://www.gnu.org/licenses/>. */
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#ifndef GCC_TREE_CHREC_H
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#define GCC_TREE_CHREC_H
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/* The following trees are unique elements. Thus the comparison of another
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element to these elements should be done on the pointer to these trees,
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and not on their value.
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extern tree chrec_not_analyzed_yet;
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extern tree chrec_dont_know;
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extern tree chrec_known;
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chrec_not_analyzed_yet is NULL_TREE and the others are defined
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in global_trees[]. */
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/* After having added an automatically generated element, please
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include it in the following function. */
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inline bool
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automatically_generated_chrec_p (const_tree chrec)
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{
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return (chrec == chrec_dont_know
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|| chrec == chrec_known);
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}
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/* The tree nodes aka. CHRECs. */
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inline bool
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tree_is_chrec (const_tree expr)
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{
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if (TREE_CODE (expr) == POLYNOMIAL_CHREC
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|| automatically_generated_chrec_p (expr))
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return true;
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else
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return false;
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}
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enum ev_direction {EV_DIR_GROWS, EV_DIR_DECREASES, EV_DIR_UNKNOWN};
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enum ev_direction scev_direction (const_tree);
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/* Chrec folding functions. */
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extern tree chrec_fold_plus (tree, tree, tree);
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extern tree chrec_fold_minus (tree, tree, tree);
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extern tree chrec_fold_multiply (tree, tree, tree);
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extern tree chrec_convert (tree, tree, gimple *, bool = true, tree = NULL);
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extern tree chrec_convert_rhs (tree, tree, gimple * = NULL);
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extern tree chrec_convert_aggressive (tree, tree, bool *);
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/* Operations. */
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extern tree chrec_apply (unsigned, tree, tree);
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extern tree chrec_apply_map (tree, vec<tree> );
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extern tree chrec_replace_initial_condition (tree, tree);
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extern tree initial_condition (tree);
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extern tree initial_condition_in_loop_num (tree, unsigned);
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extern tree evolution_part_in_loop_num (tree, unsigned);
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extern tree hide_evolution_in_other_loops_than_loop (tree, unsigned);
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extern tree reset_evolution_in_loop (unsigned, tree, tree);
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extern tree chrec_merge (tree, tree);
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extern void for_each_scev_op (tree *, bool (*) (tree *, void *), void *);
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extern bool convert_affine_scev (class loop *, tree, tree *, tree *, gimple *,
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bool, tree = NULL);
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/* Observers. */
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extern bool eq_evolutions_p (const_tree, const_tree);
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extern bool is_multivariate_chrec (const_tree);
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extern bool chrec_contains_symbols (const_tree, class loop * = NULL);
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extern bool chrec_contains_symbols_defined_in_loop (const_tree, unsigned);
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extern bool chrec_contains_undetermined (const_tree);
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extern bool tree_contains_chrecs (const_tree, int *);
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extern bool evolution_function_is_affine_multivariate_p (const_tree, int);
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extern bool evolution_function_is_univariate_p (const_tree, int = 0);
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extern unsigned nb_vars_in_chrec (tree);
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extern bool evolution_function_is_invariant_p (tree, int);
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extern bool scev_is_linear_expression (tree);
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extern bool evolution_function_right_is_integer_cst (const_tree);
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/* Determines whether CHREC is equal to zero. */
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inline bool
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chrec_zerop (const_tree chrec)
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{
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if (chrec == NULL_TREE)
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return false;
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if (TREE_CODE (chrec) == INTEGER_CST)
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return integer_zerop (chrec);
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return false;
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}
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/* Determines whether CHREC is a loop invariant with respect to LOOP_NUM.
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Set the result in RES and return true when the property can be computed. */
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inline bool
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no_evolution_in_loop_p (tree chrec, unsigned loop_num, bool *res)
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{
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tree scev;
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if (chrec == chrec_not_analyzed_yet
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|| chrec == chrec_dont_know
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|| chrec_contains_symbols_defined_in_loop (chrec, loop_num))
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return false;
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STRIP_NOPS (chrec);
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scev = hide_evolution_in_other_loops_than_loop (chrec, loop_num);
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*res = !tree_contains_chrecs (scev, NULL);
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return true;
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}
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/* Build a polynomial chain of recurrence. */
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inline tree
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build_polynomial_chrec (unsigned loop_num,
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tree left,
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tree right)
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{
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bool val;
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if (left == chrec_dont_know
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|| right == chrec_dont_know)
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return chrec_dont_know;
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if (!no_evolution_in_loop_p (left, loop_num, &val)
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|| !val)
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return chrec_dont_know;
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/* Types of left and right sides of a chrec should be compatible, but
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pointer CHRECs are special in that the evolution is of ptroff type. */
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if (POINTER_TYPE_P (TREE_TYPE (left)))
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gcc_checking_assert (ptrofftype_p (TREE_TYPE (right)));
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else
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{
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/* Pointer types should occur only on the left hand side, i.e. in
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the base of the chrec, and not in the step. */
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gcc_checking_assert (!POINTER_TYPE_P (TREE_TYPE (right))
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&& types_compatible_p (TREE_TYPE (left),
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TREE_TYPE (right)));
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}
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if (chrec_zerop (right))
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return left;
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tree chrec = build2 (POLYNOMIAL_CHREC, TREE_TYPE (left), left, right);
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CHREC_VARIABLE (chrec) = loop_num;
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return chrec;
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}
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/* Determines whether the expression CHREC is a constant. */
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inline bool
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evolution_function_is_constant_p (const_tree chrec)
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{
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if (chrec == NULL_TREE)
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return false;
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return is_gimple_min_invariant (chrec);
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}
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/* Determine whether CHREC is an affine evolution function in LOOPNUM. */
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inline bool
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evolution_function_is_affine_in_loop (const_tree chrec, int loopnum)
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{
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if (chrec == NULL_TREE)
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return false;
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switch (TREE_CODE (chrec))
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{
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case POLYNOMIAL_CHREC:
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if (evolution_function_is_invariant_p (CHREC_LEFT (chrec), loopnum)
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&& evolution_function_is_invariant_p (CHREC_RIGHT (chrec), loopnum))
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return true;
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else
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return false;
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default:
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return false;
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}
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}
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/* Determine whether CHREC is an affine evolution function or not. */
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inline bool
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evolution_function_is_affine_p (const_tree chrec)
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{
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return chrec
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&& TREE_CODE (chrec) == POLYNOMIAL_CHREC
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&& evolution_function_is_invariant_p (CHREC_RIGHT (chrec),
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CHREC_VARIABLE (chrec))
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&& (TREE_CODE (CHREC_RIGHT (chrec)) != POLYNOMIAL_CHREC
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|| evolution_function_is_affine_p (CHREC_RIGHT (chrec)));
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}
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/* Determines whether EXPR does not contains chrec expressions. */
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inline bool
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tree_does_not_contain_chrecs (const_tree expr)
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{
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return !tree_contains_chrecs (expr, NULL);
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}
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/* Returns the type of the chrec. */
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inline tree
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chrec_type (const_tree chrec)
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{
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if (automatically_generated_chrec_p (chrec))
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return NULL_TREE;
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return TREE_TYPE (chrec);
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}
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inline tree
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chrec_fold_op (enum tree_code code, tree type, tree op0, tree op1)
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{
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switch (code)
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{
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case PLUS_EXPR:
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return chrec_fold_plus (type, op0, op1);
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case MINUS_EXPR:
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return chrec_fold_minus (type, op0, op1);
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case MULT_EXPR:
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return chrec_fold_multiply (type, op0, op1);
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default:
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gcc_unreachable ();
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}
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}
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#endif /* GCC_TREE_CHREC_H */
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