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1 : /* A representation of vector permutation indices.
2 : Copyright (C) 2017-2026 Free Software Foundation, Inc.
3 :
4 : This file is part of GCC.
5 :
6 : GCC is free software; you can redistribute it and/or modify it under
7 : the terms of the GNU General Public License as published by the Free
8 : Software Foundation; either version 3, or (at your option) any later
9 : version.
10 :
11 : GCC is distributed in the hope that it will be useful, but WITHOUT ANY
12 : WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 : FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
14 : for more details.
15 :
16 : You should have received a copy of the GNU General Public License
17 : along with GCC; see the file COPYING3. If not see
18 : <http://www.gnu.org/licenses/>. */
19 :
20 : #ifndef GCC_VEC_PERN_INDICES_H
21 : #define GCC_VEC_PERN_INDICES_H 1
22 :
23 : #include "int-vector-builder.h"
24 :
25 : /* A vector_builder for building constant permutation vectors.
26 : The elements do not need to be clamped to a particular range
27 : of input elements. */
28 : typedef int_vector_builder<poly_int64> vec_perm_builder;
29 :
30 : /* This class represents a constant permutation vector, such as that used
31 : as the final operand to a VEC_PERM_EXPR.
32 :
33 : Permutation vectors select indices modulo the number of input elements,
34 : and the class canonicalizes each permutation vector for a particular
35 : number of input vectors and for a particular number of elements per
36 : input. For example, the gimple statements:
37 :
38 : _1 = VEC_PERM_EXPR <a, a, { 0, 2, 4, 6, 0, 2, 4, 6 }>;
39 : _2 = VEC_PERM_EXPR <a, a, { 0, 2, 4, 6, 8, 10, 12, 14 }>;
40 : _3 = VEC_PERM_EXPR <a, a, { 0, 2, 20, 22, 24, 2, 4, 14 }>;
41 :
42 : effectively have only a single vector input "a". If "a" has 8
43 : elements, the indices select elements modulo 8, which makes all three
44 : VEC_PERM_EXPRs equivalent. The canonical form is for the indices to be
45 : in the range [0, number of input elements - 1], so the class treats the
46 : second and third permutation vectors as though they had been the first.
47 :
48 : The class copes with cases in which the input and output vectors have
49 : different numbers of elements. */
50 4225072 : class vec_perm_indices
51 : {
52 : typedef poly_int64 element_type;
53 :
54 : public:
55 : vec_perm_indices ();
56 : vec_perm_indices (const vec_perm_builder &, unsigned int, poly_uint64);
57 :
58 : void new_vector (const vec_perm_builder &, unsigned int, poly_uint64);
59 : void new_expanded_vector (const vec_perm_indices &, unsigned int);
60 : bool new_shrunk_vector (const vec_perm_indices &, unsigned int);
61 : void rotate_inputs (int delta);
62 :
63 : /* Return the underlying vector encoding. */
64 : const vec_perm_builder &encoding () const { return m_encoding; }
65 :
66 : /* Return the number of output elements. This is called length ()
67 : so that we present a more vec-like interface. */
68 2177259 : poly_uint64 length () const { return m_encoding.full_nelts (); }
69 :
70 : /* Return the number of input vectors being permuted. */
71 18120 : unsigned int ninputs () const { return m_ninputs; }
72 :
73 : /* Return the number of elements in each input vector. */
74 1163006 : poly_uint64 nelts_per_input () const { return m_nelts_per_input; }
75 :
76 : /* Return the total number of input elements. */
77 5537546 : poly_uint64 input_nelts () const { return m_ninputs * m_nelts_per_input; }
78 :
79 : element_type clamp (element_type) const;
80 : element_type operator[] (unsigned int i) const;
81 : bool series_p (unsigned int, unsigned int, element_type, element_type) const;
82 : bool all_in_range_p (element_type, element_type) const;
83 : bool all_from_input_p (unsigned int) const;
84 :
85 : private:
86 : vec_perm_indices (const vec_perm_indices &);
87 :
88 : vec_perm_builder m_encoding;
89 : unsigned int m_ninputs;
90 : poly_uint64 m_nelts_per_input;
91 : };
92 :
93 : bool tree_to_vec_perm_builder (vec_perm_builder *, tree);
94 : tree vec_perm_indices_to_tree (tree, const vec_perm_indices &);
95 : rtx vec_perm_indices_to_rtx (machine_mode, const vec_perm_indices &);
96 :
97 : inline
98 1242611 : vec_perm_indices::vec_perm_indices ()
99 1242611 : : m_ninputs (0),
100 1242611 : m_nelts_per_input (0)
101 : {
102 : }
103 :
104 : /* Construct a permutation vector that selects between NINPUTS vector
105 : inputs that have NELTS_PER_INPUT elements each. Take the elements of
106 : the new vector from ELEMENTS, clamping each one to be in range. */
107 :
108 : inline
109 3134599 : vec_perm_indices::vec_perm_indices (const vec_perm_builder &elements,
110 : unsigned int ninputs,
111 3134599 : poly_uint64 nelts_per_input)
112 : {
113 3134599 : new_vector (elements, ninputs, nelts_per_input);
114 3134599 : }
115 :
116 : /* Return the canonical value for permutation vector element ELT,
117 : taking into account the current number of input elements. */
118 :
119 : inline vec_perm_indices::element_type
120 50178094 : vec_perm_indices::clamp (element_type elt) const
121 : {
122 43049141 : element_type limit = input_nelts (), elem_within_input;
123 50178094 : HOST_WIDE_INT input;
124 50178094 : if (!can_div_trunc_p (elt, limit, &input, &elem_within_input))
125 : return elt;
126 :
127 : /* Treat negative elements as counting from the end. This only matters
128 : if the vector size is not a power of 2. */
129 50178094 : if (known_lt (elem_within_input, 0))
130 417889 : return elem_within_input + limit;
131 :
132 : return elem_within_input;
133 : }
134 :
135 : /* Return the value of vector element I, which might or might not be
136 : explicitly encoded. */
137 :
138 : inline vec_perm_indices::element_type
139 12290292 : vec_perm_indices::operator[] (unsigned int i) const
140 : {
141 12290292 : return clamp (m_encoding.elt (i));
142 : }
143 :
144 : /* Return true if the permutation vector only selects elements from
145 : input I. */
146 :
147 : inline bool
148 2249664 : vec_perm_indices::all_from_input_p (unsigned int i) const
149 : {
150 2249664 : return all_in_range_p (i * m_nelts_per_input, m_nelts_per_input);
151 : }
152 :
153 : #endif
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