vec-perm-indices.h revision 1.1.1.2
1 /* A representation of vector permutation indices. 2 Copyright (C) 2017-2019 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 void rotate_inputs (int delta); 61 62 /* Return the underlying vector encoding. */ 63 const vec_perm_builder &encoding () const { return m_encoding; } 64 65 /* Return the number of output elements. This is called length () 66 so that we present a more vec-like interface. */ 67 poly_uint64 length () const { return m_encoding.full_nelts (); } 68 69 /* Return the number of input vectors being permuted. */ 70 unsigned int ninputs () const { return m_ninputs; } 71 72 /* Return the number of elements in each input vector. */ 73 poly_uint64 nelts_per_input () const { return m_nelts_per_input; } 74 75 /* Return the total number of input elements. */ 76 poly_uint64 input_nelts () const { return m_ninputs * m_nelts_per_input; } 77 78 element_type clamp (element_type) const; 79 element_type operator[] (unsigned int i) const; 80 bool series_p (unsigned int, unsigned int, element_type, element_type) const; 81 bool all_in_range_p (element_type, element_type) const; 82 bool all_from_input_p (unsigned int) const; 83 84 private: 85 vec_perm_indices (const vec_perm_indices &); 86 87 vec_perm_builder m_encoding; 88 unsigned int m_ninputs; 89 poly_uint64 m_nelts_per_input; 90 }; 91 92 bool tree_to_vec_perm_builder (vec_perm_builder *, tree); 93 tree vec_perm_indices_to_tree (tree, const vec_perm_indices &); 94 rtx vec_perm_indices_to_rtx (machine_mode, const vec_perm_indices &); 95 96 inline 97 vec_perm_indices::vec_perm_indices () 98 : m_ninputs (0), 99 m_nelts_per_input (0) 100 { 101 } 102 103 /* Construct a permutation vector that selects between NINPUTS vector 104 inputs that have NELTS_PER_INPUT elements each. Take the elements of 105 the new vector from ELEMENTS, clamping each one to be in range. */ 106 107 inline 108 vec_perm_indices::vec_perm_indices (const vec_perm_builder &elements, 109 unsigned int ninputs, 110 poly_uint64 nelts_per_input) 111 { 112 new_vector (elements, ninputs, nelts_per_input); 113 } 114 115 /* Return the canonical value for permutation vector element ELT, 116 taking into account the current number of input elements. */ 117 118 inline vec_perm_indices::element_type 119 vec_perm_indices::clamp (element_type elt) const 120 { 121 element_type limit = input_nelts (), elem_within_input; 122 HOST_WIDE_INT input; 123 if (!can_div_trunc_p (elt, limit, &input, &elem_within_input)) 124 return elt; 125 126 /* Treat negative elements as counting from the end. This only matters 127 if the vector size is not a power of 2. */ 128 if (known_lt (elem_within_input, 0)) 129 return elem_within_input + limit; 130 131 return elem_within_input; 132 } 133 134 /* Return the value of vector element I, which might or might not be 135 explicitly encoded. */ 136 137 inline vec_perm_indices::element_type 138 vec_perm_indices::operator[] (unsigned int i) const 139 { 140 return clamp (m_encoding.elt (i)); 141 } 142 143 /* Return true if the permutation vector only selects elements from 144 input I. */ 145 146 inline bool 147 vec_perm_indices::all_from_input_p (unsigned int i) const 148 { 149 return all_in_range_p (i * m_nelts_per_input, m_nelts_per_input); 150 } 151 152 #endif 153
Indexes created Wed May 06 00:24:28 UTC 2026