1/* Fold a constant sub-tree into a single node for C-compiler
2 Copyright (C) 1987-2023 Free Software Foundation, Inc.
3
4This file is part of GCC.
5
6GCC is free software; you can redistribute it and/or modify it under
7the terms of the GNU General Public License as published by the Free
8Software Foundation; either version 3, or (at your option) any later
9version.
10
11GCC is distributed in the hope that it will be useful, but WITHOUT ANY
12WARRANTY; without even the implied warranty of MERCHANTABILITY or
13FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
14for more details.
15
16You should have received a copy of the GNU General Public License
17along with GCC; see the file COPYING3. If not see
18<http://www.gnu.org/licenses/>. */
19
20#ifndef GCC_FOLD_CONST_H
21#define GCC_FOLD_CONST_H
22
23/* Nonzero if we are folding constants inside an initializer or a C++
24 manifestly-constant-evaluated context; zero otherwise.
25 Should be used when folding in initializer enables additional
26 optimizations. */
27extern int folding_initializer;
28/* Nonzero if we are folding C++ manifestly-constant-evaluated context; zero
29 otherwise.
30 Should be used when certain constructs shouldn't be optimized
31 during folding in that context. */
32extern bool folding_cxx_constexpr;
33
34/* Convert between trees and native memory representation. */
35extern int native_encode_expr (const_tree, unsigned char *, int, int off = -1);
36extern int native_encode_initializer (tree, unsigned char *, int,
37 int off = -1, unsigned char * = nullptr);
38extern tree native_interpret_expr (tree, const unsigned char *, int);
39extern tree native_interpret_real (tree, const unsigned char *, int);
40extern bool can_native_interpret_type_p (tree);
41extern tree native_interpret_aggregate (tree, const unsigned char *, int, int);
42extern tree find_bitfield_repr_type (int, int);
43extern void shift_bytes_in_array_left (unsigned char *, unsigned int,
44 unsigned int);
45extern void shift_bytes_in_array_right (unsigned char *, unsigned int,
46 unsigned int);
47
48/* Fold constants as much as possible in an expression.
49 Returns the simplified expression.
50 Acts only on the top level of the expression;
51 if the argument itself cannot be simplified, its
52 subexpressions are not changed. */
53
54extern tree fold (tree);
55extern tree fold_init (tree);
56#define fold_unary(CODE,T1,T2)\
57 fold_unary_loc (UNKNOWN_LOCATION, CODE, T1, T2)
58extern tree fold_unary_loc (location_t, enum tree_code, tree, tree);
59#define fold_unary_ignore_overflow(CODE,T1,T2)\
60 fold_unary_ignore_overflow_loc (UNKNOWN_LOCATION, CODE, T1, T2)
61extern tree fold_unary_ignore_overflow_loc (location_t, enum tree_code, tree, tree);
62#define fold_binary(CODE,T1,T2,T3)\
63 fold_binary_loc (UNKNOWN_LOCATION, CODE, T1, T2, T3)
64extern tree fold_binary_loc (location_t, enum tree_code, tree, tree, tree);
65#define fold_ternary(CODE,T1,T2,T3,T4)\
66 fold_ternary_loc (UNKNOWN_LOCATION, CODE, T1, T2, T3, T4)
67extern tree fold_ternary_loc (location_t, enum tree_code, tree, tree, tree, tree);
68#define fold_build1(c,t1,t2)\
69 fold_build1_loc (UNKNOWN_LOCATION, c, t1, t2 MEM_STAT_INFO)
70extern tree fold_build1_loc (location_t, enum tree_code, tree,
71 tree CXX_MEM_STAT_INFO);
72#define fold_build2(c,t1,t2,t3)\
73 fold_build2_loc (UNKNOWN_LOCATION, c, t1, t2, t3 MEM_STAT_INFO)
74extern tree fold_build2_loc (location_t, enum tree_code, tree, tree,
75 tree CXX_MEM_STAT_INFO);
76#define fold_build3(c,t1,t2,t3,t4)\
77 fold_build3_loc (UNKNOWN_LOCATION, c, t1, t2, t3, t4 MEM_STAT_INFO)
78extern tree fold_build3_loc (location_t, enum tree_code, tree, tree, tree,
79 tree CXX_MEM_STAT_INFO);
80extern tree fold_build1_initializer_loc (location_t, enum tree_code, tree, tree);
81extern tree fold_build2_initializer_loc (location_t, enum tree_code, tree, tree, tree);
82#define fold_build_call_array(T1,T2,N,T4)\
83 fold_build_call_array_loc (UNKNOWN_LOCATION, T1, T2, N, T4)
84extern tree fold_build_call_array_loc (location_t, tree, tree, int, tree *);
85#define fold_build_call_array_initializer(T1,T2,N,T4)\
86 fold_build_call_array_initializer_loc (UNKNOWN_LOCATION, T1, T2, N, T4)
87extern tree fold_build_call_array_initializer_loc (location_t, tree, tree, int, tree *);
88extern tree fold_binary_initializer_loc (location_t, tree_code, tree, tree, tree);
89extern tree get_array_ctor_element_at_index (tree, offset_int,
90 unsigned * = NULL);
91extern bool fold_convertible_p (const_tree, const_tree);
92#define fold_convert(T1,T2)\
93 fold_convert_loc (UNKNOWN_LOCATION, T1, T2)
94extern tree fold_convert_loc (location_t, tree, tree);
95extern tree fold_ignored_result (tree);
96extern tree fold_abs_const (tree, tree);
97extern tree fold_indirect_ref_1 (location_t, tree, tree);
98extern void fold_defer_overflow_warnings (void);
99extern void fold_undefer_overflow_warnings (bool, const gimple *, int);
100extern void fold_undefer_and_ignore_overflow_warnings (void);
101extern bool fold_deferring_overflow_warnings_p (void);
102extern void fold_overflow_warning (const char*, enum warn_strict_overflow_code);
103extern enum tree_code fold_div_compare (enum tree_code, tree, tree,
104 tree *, tree *, bool *);
105extern bool operand_equal_p (const_tree, const_tree, unsigned int flags = 0);
106extern bool multiple_of_p (tree, const_tree, const_tree, bool = true);
107#define omit_one_operand(T1,T2,T3)\
108 omit_one_operand_loc (UNKNOWN_LOCATION, T1, T2, T3)
109extern tree omit_one_operand_loc (location_t, tree, tree, tree);
110#define omit_two_operands(T1,T2,T3,T4)\
111 omit_two_operands_loc (UNKNOWN_LOCATION, T1, T2, T3, T4)
112extern tree omit_two_operands_loc (location_t, tree, tree, tree, tree);
113#define invert_truthvalue(T)\
114 invert_truthvalue_loc (UNKNOWN_LOCATION, T)
115extern tree invert_truthvalue_loc (location_t, tree);
116extern tree fold_unary_to_constant (enum tree_code, tree, tree);
117extern tree fold_binary_to_constant (enum tree_code, tree, tree, tree);
118extern tree fold_bit_and_mask (tree, tree, enum tree_code,
119 tree, enum tree_code, tree, tree,
120 tree, enum tree_code, tree, tree, tree *);
121extern tree fold_read_from_constant_string (tree);
122extern tree fold_read_from_vector (tree, poly_uint64);
123#if GCC_VEC_PERN_INDICES_H
124extern tree fold_vec_perm (tree, tree, tree, const vec_perm_indices &);
125#endif
126extern bool wide_int_binop (wide_int &res, enum tree_code,
127 const wide_int &arg1, const wide_int &arg2,
128 signop, wi::overflow_type *);
129extern tree int_const_binop (enum tree_code, const_tree, const_tree, int = 1);
130#define build_fold_addr_expr(T)\
131 build_fold_addr_expr_loc (UNKNOWN_LOCATION, (T))
132extern tree build_fold_addr_expr_loc (location_t, tree);
133#define build_fold_addr_expr_with_type(T,TYPE)\
134 build_fold_addr_expr_with_type_loc (UNKNOWN_LOCATION, (T), TYPE)
135extern tree build_fold_addr_expr_with_type_loc (location_t, tree, tree);
136extern tree fold_build_cleanup_point_expr (tree type, tree expr);
137#define build_fold_indirect_ref(T)\
138 build_fold_indirect_ref_loc (UNKNOWN_LOCATION, T)
139extern tree build_fold_indirect_ref_loc (location_t, tree);
140#define fold_indirect_ref(T)\
141 fold_indirect_ref_loc (UNKNOWN_LOCATION, T)
142extern tree fold_indirect_ref_loc (location_t, tree);
143extern tree build_simple_mem_ref_loc (location_t, tree);
144#define build_simple_mem_ref(T)\
145 build_simple_mem_ref_loc (UNKNOWN_LOCATION, T)
146extern poly_offset_int mem_ref_offset (const_tree);
147extern tree build_invariant_address (tree, tree, poly_int64);
148extern tree constant_boolean_node (bool, tree);
149extern tree div_if_zero_remainder (const_tree, const_tree);
150
151extern bool tree_swap_operands_p (const_tree, const_tree);
152extern enum tree_code swap_tree_comparison (enum tree_code);
153
154extern bool ptr_difference_const (tree, tree, poly_int64 *);
155extern enum tree_code invert_tree_comparison (enum tree_code, bool);
156extern bool inverse_conditions_p (const_tree, const_tree);
157
158extern bool tree_unary_nonzero_warnv_p (enum tree_code, tree, tree, bool *);
159extern bool tree_binary_nonzero_warnv_p (enum tree_code, tree, tree, tree op1,
160 bool *);
161extern bool tree_single_nonzero_warnv_p (tree, bool *);
162extern bool tree_unary_nonnegative_warnv_p (enum tree_code, tree, tree,
163 bool *, int);
164extern bool tree_binary_nonnegative_warnv_p (enum tree_code, tree, tree, tree,
165 bool *, int);
166extern bool tree_single_nonnegative_warnv_p (tree, bool *, int);
167extern bool tree_call_nonnegative_warnv_p (tree, combined_fn, tree, tree,
168 bool *, int);
169
170extern bool integer_valued_real_unary_p (tree_code, tree, int);
171extern bool integer_valued_real_binary_p (tree_code, tree, tree, int);
172extern bool integer_valued_real_call_p (combined_fn, tree, tree, int);
173extern bool integer_valued_real_single_p (tree, int);
174extern bool integer_valued_real_p (tree, int = 0);
175
176extern bool fold_real_zero_addition_p (const_tree, const_tree, const_tree,
177 int);
178extern tree combine_comparisons (location_t, enum tree_code, enum tree_code,
179 enum tree_code, tree, tree, tree);
180extern void debug_fold_checksum (const_tree);
181extern bool may_negate_without_overflow_p (const_tree);
182#define round_up(T,N) round_up_loc (UNKNOWN_LOCATION, T, N)
183extern tree round_up_loc (location_t, tree, unsigned int);
184#define round_down(T,N) round_down_loc (UNKNOWN_LOCATION, T, N)
185extern tree round_down_loc (location_t, tree, int);
186extern tree size_int_kind (poly_int64, enum size_type_kind);
187#define size_binop(CODE,T1,T2)\
188 size_binop_loc (UNKNOWN_LOCATION, CODE, T1, T2)
189extern tree size_binop_loc (location_t, enum tree_code, tree, tree);
190#define size_diffop(T1,T2)\
191 size_diffop_loc (UNKNOWN_LOCATION, T1, T2)
192extern tree size_diffop_loc (location_t, tree, tree);
193
194/* Return an expr equal to X but certainly not valid as an lvalue. */
195#define non_lvalue(T) non_lvalue_loc (UNKNOWN_LOCATION, T)
196extern tree non_lvalue_loc (location_t, tree);
197
198extern bool tree_expr_nonzero_p (tree);
199extern bool tree_expr_nonnegative_p (tree);
200extern bool tree_expr_nonnegative_warnv_p (tree, bool *, int = 0);
201extern bool tree_expr_finite_p (const_tree);
202extern bool tree_expr_infinite_p (const_tree);
203extern bool tree_expr_maybe_infinite_p (const_tree);
204extern bool tree_expr_signaling_nan_p (const_tree);
205extern bool tree_expr_maybe_signaling_nan_p (const_tree);
206extern bool tree_expr_nan_p (const_tree);
207extern bool tree_expr_maybe_nan_p (const_tree);
208extern bool tree_expr_maybe_real_minus_zero_p (const_tree);
209extern tree make_range (tree, int *, tree *, tree *, bool *);
210extern tree make_range_step (location_t, enum tree_code, tree, tree, tree,
211 tree *, tree *, int *, bool *);
212extern tree range_check_type (tree);
213extern tree build_range_check (location_t, tree, tree, int, tree, tree);
214extern bool merge_ranges (int *, tree *, tree *, int, tree, tree, int,
215 tree, tree);
216extern tree sign_bit_p (tree, const_tree);
217extern bool simple_condition_p (tree);
218extern tree exact_inverse (tree, tree);
219extern bool expr_not_equal_to (tree t, const wide_int &);
220extern tree const_unop (enum tree_code, tree, tree);
221extern tree const_binop (enum tree_code, tree, tree, tree);
222extern bool negate_mathfn_p (combined_fn);
223extern const char *getbyterep (tree, unsigned HOST_WIDE_INT *);
224extern const char *c_getstr (tree);
225extern wide_int tree_nonzero_bits (const_tree);
226extern int address_compare (tree_code, tree, tree, tree, tree &, tree &,
227 poly_int64 &, poly_int64 &, bool);
228extern tree ctor_single_nonzero_element (const_tree);
229
230/* Return OFF converted to a pointer offset type suitable as offset for
231 POINTER_PLUS_EXPR. Use location LOC for this conversion. */
232extern tree convert_to_ptrofftype_loc (location_t loc, tree off);
233
234#define convert_to_ptrofftype(t) convert_to_ptrofftype_loc (UNKNOWN_LOCATION, t)
235
236/* Build and fold a POINTER_PLUS_EXPR at LOC offsetting PTR by OFF. */
237extern tree fold_build_pointer_plus_loc (location_t loc, tree ptr, tree off);
238
239#define fold_build_pointer_plus(p,o) \
240 fold_build_pointer_plus_loc (UNKNOWN_LOCATION, p, o)
241
242/* Build and fold a POINTER_PLUS_EXPR at LOC offsetting PTR by OFF. */
243extern tree fold_build_pointer_plus_hwi_loc (location_t loc, tree ptr, HOST_WIDE_INT off);
244
245#define fold_build_pointer_plus_hwi(p,o) \
246 fold_build_pointer_plus_hwi_loc (UNKNOWN_LOCATION, p, o)
247
248extern tree_code minmax_from_comparison (tree_code, tree, tree,
249 tree, tree);
250
251/* In gimple-fold.cc. */
252extern void clear_type_padding_in_mask (tree, unsigned char *);
253extern bool clear_padding_type_may_have_padding_p (tree);
254extern bool arith_overflowed_p (enum tree_code, const_tree, const_tree,
255 const_tree);
256
257/* Class used to compare gimple operands. */
258
259class operand_compare
260{
261public:
262 /* Return true if two operands are equal. The flags fields can be used
263 to specify OEP flags described in tree-core.h. */
264 virtual bool operand_equal_p (const_tree, const_tree, unsigned int flags);
265
266 /* Generate a hash value for an expression. This can be used iteratively
267 by passing a previous result as the HSTATE argument. */
268 virtual void hash_operand (const_tree, inchash::hash &, unsigned flags);
269
270protected:
271 /* Verify that when arguments (ARG0 and ARG1) are equal, then they have
272 an equal hash value. When the function knowns comparison return,
273 true is returned. Then RET is set to corresponding comparsion result. */
274 bool verify_hash_value (const_tree arg0, const_tree arg1, unsigned int flags,
275 bool *ret);
276};
277
278#endif // GCC_FOLD_CONST_H
279

source code of gcc/fold-const.h