xref: /netbsd-src/external/gpl3/gcc.old/dist/gcc/tree-vector-builder.h (revision 4c3eb207d36f67d31994830c0a694161fc1ca39b)
1 /* A class for building vector tree constants.
2    Copyright (C) 2017-2020 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_TREE_VECTOR_BUILDER_H
21 #define GCC_TREE_VECTOR_BUILDER_H
22 
23 #include "vector-builder.h"
24 
25 /* This class is used to build VECTOR_CSTs from a sequence of elements.
26    See vector_builder for more details.  */
27 class tree_vector_builder : public vector_builder<tree, tree,
28 						  tree_vector_builder>
29 {
30   typedef vector_builder<tree, tree, tree_vector_builder> parent;
31   friend class vector_builder<tree, tree, tree_vector_builder>;
32 
33 public:
tree_vector_builder()34   tree_vector_builder () : m_type (0) {}
35   tree_vector_builder (tree, unsigned int, unsigned int);
36   tree build ();
37 
type()38   tree type () const { return m_type; }
39 
40   void new_vector (tree, unsigned int, unsigned int);
41 
42 private:
43   bool equal_p (const_tree, const_tree) const;
44   bool allow_steps_p () const;
45   bool integral_p (const_tree) const;
46   wide_int step (const_tree, const_tree) const;
47   tree apply_step (tree, unsigned int, const wide_int &) const;
48   bool can_elide_p (const_tree) const;
49   void note_representative (tree *, tree);
50 
shape_nelts(const_tree t)51   static poly_uint64 shape_nelts (const_tree t)
52     { return TYPE_VECTOR_SUBPARTS (t); }
nelts_of(const_tree t)53   static poly_uint64 nelts_of (const_tree t)
54     { return VECTOR_CST_NELTS (t); }
npatterns_of(const_tree t)55   static unsigned int npatterns_of (const_tree t)
56     { return VECTOR_CST_NPATTERNS (t); }
nelts_per_pattern_of(const_tree t)57   static unsigned int nelts_per_pattern_of (const_tree t)
58     { return VECTOR_CST_NELTS_PER_PATTERN (t); }
59 
60   tree m_type;
61 };
62 
63 /* Create a new builder for a vector of type TYPE.  Initially encode the
64    value as NPATTERNS interleaved patterns with NELTS_PER_PATTERN elements
65    each.  */
66 
67 inline
tree_vector_builder(tree type,unsigned int npatterns,unsigned int nelts_per_pattern)68 tree_vector_builder::tree_vector_builder (tree type, unsigned int npatterns,
69 					  unsigned int nelts_per_pattern)
70 {
71   new_vector (type, npatterns, nelts_per_pattern);
72 }
73 
74 /* Start building a new vector of type TYPE.  Initially encode the value
75    as NPATTERNS interleaved patterns with NELTS_PER_PATTERN elements each.  */
76 
77 inline void
new_vector(tree type,unsigned int npatterns,unsigned int nelts_per_pattern)78 tree_vector_builder::new_vector (tree type, unsigned int npatterns,
79 				 unsigned int nelts_per_pattern)
80 {
81   m_type = type;
82   parent::new_vector (TYPE_VECTOR_SUBPARTS (type), npatterns,
83 		      nelts_per_pattern);
84 }
85 
86 /* Return true if elements I1 and I2 are equal.  */
87 
88 inline bool
equal_p(const_tree elt1,const_tree elt2)89 tree_vector_builder::equal_p (const_tree elt1, const_tree elt2) const
90 {
91   return operand_equal_p (elt1, elt2, OEP_BITWISE);
92 }
93 
94 /* Return true if a stepped representation is OK.  We don't allow
95    linear series for anything other than integers, to avoid problems
96    with rounding.  */
97 
98 inline bool
allow_steps_p()99 tree_vector_builder::allow_steps_p () const
100 {
101   return INTEGRAL_TYPE_P (TREE_TYPE (m_type));
102 }
103 
104 /* Return true if ELT can be interpreted as an integer.  */
105 
106 inline bool
integral_p(const_tree elt)107 tree_vector_builder::integral_p (const_tree elt) const
108 {
109   return TREE_CODE (elt) == INTEGER_CST;
110 }
111 
112 /* Return the value of element ELT2 minus the value of element ELT1.
113    Both elements are known to be INTEGER_CSTs.  */
114 
115 inline wide_int
step(const_tree elt1,const_tree elt2)116 tree_vector_builder::step (const_tree elt1, const_tree elt2) const
117 {
118   return wi::to_wide (elt2) - wi::to_wide (elt1);
119 }
120 
121 /* Return true if we can drop element ELT, even if the retained elements
122    are different.  Return false if this would mean losing overflow
123    information.  */
124 
125 inline bool
can_elide_p(const_tree elt)126 tree_vector_builder::can_elide_p (const_tree elt) const
127 {
128   return !CONSTANT_CLASS_P (elt) || !TREE_OVERFLOW (elt);
129 }
130 
131 /* Record that ELT2 is being elided, given that ELT1_PTR points to the last
132    encoded element for the containing pattern.  */
133 
134 inline void
note_representative(tree * elt1_ptr,tree elt2)135 tree_vector_builder::note_representative (tree *elt1_ptr, tree elt2)
136 {
137   if (CONSTANT_CLASS_P (elt2) && TREE_OVERFLOW (elt2))
138     {
139       gcc_assert (operand_equal_p (*elt1_ptr, elt2, 0));
140       if (!TREE_OVERFLOW (elt2))
141 	*elt1_ptr = elt2;
142     }
143 }
144 
145 #endif
146