1 | /* A representation of vector permutation indices. |
2 | Copyright (C) 2017-2023 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 | 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 | poly_uint64 length () const { return m_encoding.full_nelts (); } |
69 | |
70 | /* Return the number of input vectors being permuted. */ |
71 | unsigned int ninputs () const { return m_ninputs; } |
72 | |
73 | /* Return the number of elements in each input vector. */ |
74 | poly_uint64 nelts_per_input () const { return m_nelts_per_input; } |
75 | |
76 | /* Return the total number of input elements. */ |
77 | 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 | vec_perm_indices::vec_perm_indices () |
99 | : m_ninputs (0), |
100 | 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 | vec_perm_indices::vec_perm_indices (const vec_perm_builder &elements, |
110 | unsigned int ninputs, |
111 | poly_uint64 nelts_per_input) |
112 | { |
113 | new_vector (elements, ninputs, nelts_per_input); |
114 | } |
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 | vec_perm_indices::clamp (element_type elt) const |
121 | { |
122 | element_type limit = input_nelts (), elem_within_input; |
123 | HOST_WIDE_INT input; |
124 | if (!can_div_trunc_p (a: elt, b: limit, quotient: &input, remainder: &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 | if (known_lt (elem_within_input, 0)) |
130 | 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 | vec_perm_indices::operator[] (unsigned int i) const |
140 | { |
141 | return clamp (elt: 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 | vec_perm_indices::all_from_input_p (unsigned int i) const |
149 | { |
150 | return all_in_range_p (i * m_nelts_per_input, m_nelts_per_input); |
151 | } |
152 | |
153 | #endif |
154 | |