gcc/gimple-range-fold.h

   1 /* Header file for the GIMPLE fold_using_range interface.
   2    Copyright (C) 2019-2021 Free Software Foundation, Inc.
   3    Contributed by Andrew MacLeod <amacleod@redhat.com>
   4    and Aldy Hernandez <aldyh@redhat.com>.
   5
   6 This file is part of GCC.
   7
   8 GCC is free software; you can redistribute it and/or modify it under
   9 the terms of the GNU General Public License as published by the Free
  10 Software Foundation; either version 3, or (at your option) any later
  11 version.
  12
  13 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
  14 WARRANTY; without even the implied warranty of MERCHANTABILITY or
  15 FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  16  for more details.
  17
  18 You should have received a copy of the GNU General Public License
  19 along with GCC; see the file COPYING3.  If not see
  20 <http://www.gnu.org/licenses/>.  */
  21
  22 #ifndef GCC_GIMPLE_RANGE_FOLD_H
  23 #define GCC_GIMPLE_RANGE_FOLD_H
  24
  25 // This file is the main include point for gimple range folding.
  26 // These routines will fold stmt S into the result irange R.
  27 // Any ssa_names on the stmt will be calculated using the range_query
  28 // parameter via a call to range_of_expr.
  29 // If no range_query is provided, current global range info will be used.
  30 // The second variation specifies an edge, and stmt S is recalculated as if
  31 // it appeared on that edge.
  32
  33 // Fold stmt S into range R using range query Q.
  34 bool fold_range (irange &r, gimple *s, range_query *q = NULL);
  35 // Recalculate stmt S into R using range query Q as if it were on edge ON_EDGE.
  36 bool fold_range (irange &r, gimple *s, edge on_edge, range_query *q = NULL);
  37
  38 // These routines the operands to be specified when manually folding.
  39 // Any excess queries will be drawn from the current range_query.
  40 bool fold_range (irange &r, gimple *s, irange &r1);
  41 bool fold_range (irange &r, gimple *s, irange &r1, irange &r2);
  42 bool fold_range (irange &r, gimple *s, unsigned num_elements, irange *vector);
  43
  44 // Return the range_operator pointer for this statement.  This routine
  45 // can also be used to gate whether a routine is range-ops enabled.
  46
  47 static inline range_operator *
  48 gimple_range_handler (const gimple *s)
  49 {
  50   if (const gassign *ass = dyn_cast<const gassign *> (s))
  51     return range_op_handler (gimple_assign_rhs_code (ass),
  52                              TREE_TYPE (gimple_assign_lhs (ass)));
  53   if (const gcond *cond = dyn_cast<const gcond *> (s))
  54     return range_op_handler (gimple_cond_code (cond),
  55                              TREE_TYPE (gimple_cond_lhs (cond)));
  56   return NULL;
  57 }
  58
  59 // Return the type of range which statement S calculates.  If the type is
  60 // unsupported or no type can be determined, return NULL_TREE.
  61
  62 static inline tree
  63 gimple_range_type (const gimple *s)
  64 {
  65   tree lhs = gimple_get_lhs (s);
  66   tree type = NULL_TREE;
  67   if (lhs)
  68     type = TREE_TYPE (lhs);
  69   else
  70     {
  71       enum gimple_code code = gimple_code (s);
  72       if (code == GIMPLE_COND)
  73         type = boolean_type_node;
  74       else if (code == GIMPLE_PHI)
  75         type = TREE_TYPE (gimple_phi_result (s));
  76       else if (code == GIMPLE_CALL)
  77         {
  78           type = gimple_call_fntype (s);
  79           // If it has a type, get the return type.
  80           if (type)
  81             type = TREE_TYPE (type);
  82         }
  83     }
  84   if (irange::supports_type_p (type))
  85     return type;
  86   return NULL_TREE;
  87 }
  88
  89 // Return EXP if it is an SSA_NAME with a type supported by gimple ranges.
  90
  91 static inline tree
  92 gimple_range_ssa_p (tree exp)
  93 {
  94   if (exp && TREE_CODE (exp) == SSA_NAME &&
  95       !SSA_NAME_IS_VIRTUAL_OPERAND (exp) &&
  96       !SSA_NAME_OCCURS_IN_ABNORMAL_PHI (exp) &&
  97       irange::supports_type_p (TREE_TYPE (exp)))
  98     return exp;
  99   return NULL_TREE;
 100 }
 101
 102 // Return true if TYPE1 and TYPE2 are compatible range types.
 103
 104 static inline bool
 105 range_compatible_p (tree type1, tree type2)
 106 {
 107   // types_compatible_p requires conversion in both directions to be useless.
 108   // GIMPLE only requires a cast one way in order to be compatible.
 109   // Ranges really only need the sign and precision to be the same.
 110   return (TYPE_PRECISION (type1) == TYPE_PRECISION (type2)
 111           && TYPE_SIGN (type1) == TYPE_SIGN (type2));
 112 }
 113
 114
 115 // Source of all operands for fold_using_range and gori_compute.
 116 // It abstracts out the source of an operand so it can come from a stmt or
 117 // and edge or anywhere a derived class of fur_source wants.
 118 // The default simply picks up ranges from the current range_query.
 119
 120 class fur_source
 121 {
 122 public:
 123   fur_source (range_query *q = NULL);
 124   inline range_query *query () { return m_query; }
 125   inline class gori_compute *gori () { return m_gori; };
 126   virtual bool get_operand (irange &r, tree expr);
 127   virtual bool get_phi_operand (irange &r, tree expr, edge e);
 128   virtual relation_kind query_relation (tree op1, tree op2);
 129   virtual void register_relation (gimple *stmt, relation_kind k, tree op1,
 130                                   tree op2);
 131   virtual void register_relation (edge e, relation_kind k, tree op1,
 132                                   tree op2);
 133   void register_outgoing_edges (gcond *, irange &lhs_range, edge e0, edge e1);
 134 protected:
 135   range_query *m_query;
 136   gori_compute *m_gori;
 137 };
 138
 139 // fur_stmt is the specification for drawing an operand from range_query Q
 140 // via a range_of_Expr call on stmt S.
 141
 142 class fur_stmt : public fur_source
 143 {
 144 public:
 145   fur_stmt (gimple *s, range_query *q = NULL);
 146   virtual bool get_operand (irange &r, tree expr) OVERRIDE;
 147   virtual bool get_phi_operand (irange &r, tree expr, edge e) OVERRIDE;
 148   virtual relation_kind query_relation (tree op1, tree op2) OVERRIDE;
 149 private:
 150   gimple *m_stmt;
 151 };
 152
 153 // This version of fur_source will pick a range from a stmt, and also register
 154 // dependencies via a gori_compute object.  This is mostly an internal API.
 155
 156 class fur_depend : public fur_stmt
 157 {
 158 public:
 159   fur_depend (gimple *s, gori_compute *gori, range_query *q = NULL);
 160   virtual void register_relation (gimple *stmt, relation_kind k, tree op1,
 161                                   tree op2) OVERRIDE;
 162   virtual void register_relation (edge e, relation_kind k, tree op1,
 163                                   tree op2) OVERRIDE;
 164 protected:
 165   relation_oracle *m_oracle;
 166 };
 167
 168 extern tree gimple_range_operand1 (const gimple *s);
 169 extern tree gimple_range_operand2 (const gimple *s);
 170
 171 // This class uses ranges to fold a gimple statement producinf a range for
 172 // the LHS.  The source of all operands is supplied via the fur_source class
 173 // which provides a range_query as well as a source location and any other
 174 // required information.
 175
 176 class fold_using_range
 177 {
 178 public:
 179   bool fold_stmt (irange &r, gimple *s, class fur_source &src,
 180                   tree name = NULL_TREE);
 181 protected:
 182   bool range_of_range_op (irange &r, gimple *s, fur_source &src);
 183   bool range_of_call (irange &r, gcall *call, fur_source &src);
 184   bool range_of_cond_expr (irange &r, gassign* cond, fur_source &src);
 185   bool range_of_address (irange &r, gimple *s, fur_source &src);
 186   bool range_of_builtin_call (irange &r, gcall *call, fur_source &src);
 187   void range_of_builtin_ubsan_call (irange &r, gcall *call, tree_code code,
 188                                     fur_source &src);
 189   bool range_of_phi (irange &r, gphi *phi, fur_source &src);
 190   void range_of_ssa_name_with_loop_info (irange &, tree, class loop *, gphi *,
 191                                          fur_source &src);
 192   void relation_fold_and_or (irange& lhs_range, gimple *s, fur_source &src);
 193 };
 194 #endif // GCC_GIMPLE_RANGE_FOLD_H