frontends/ast/ast.h

   1 /*
   2  *  yosys -- Yosys Open SYnthesis Suite
   3  *
   4  *  Copyright (C) 2012  Clifford Wolf <clifford@clifford.at>
   5  *
   6  *  Permission to use, copy, modify, and/or distribute this software for any
   7  *  purpose with or without fee is hereby granted, provided that the above
   8  *  copyright notice and this permission notice appear in all copies.
   9  *
  10  *  THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
  11  *  WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
  12  *  MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
  13  *  ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
  14  *  WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
  15  *  ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
  16  *  OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  17  *
  18  *  ---
  19  *
  20  *  This is the AST frontend library.
  21  *
  22  *  The AST frontend library is not a frontend on it's own but provides a
  23  *  generic abstract syntax tree (AST) abstraction for HDL code and can be
  24  *  used by HDL frontends. See "ast.h" for an overview of the API and the
  25  *  Verilog frontend for an usage example.
  26  *
  27  */
  28
  29 #ifndef AST_H
  30 #define AST_H
  31
  32 #include "kernel/rtlil.h"
  33 #include <stdint.h>
  34 #include <set>
  35
  36 namespace AST
  37 {
  38         // all node types, type2str() must be extended
  39         // whenever a new node type is added here
  40         enum AstNodeType
  41         {
  42                 AST_NONE,
  43                 AST_DESIGN,
  44                 AST_MODULE,
  45                 AST_TASK,
  46                 AST_FUNCTION,
  47
  48                 AST_WIRE,
  49                 AST_MEMORY,
  50                 AST_AUTOWIRE,
  51                 AST_PARAMETER,
  52                 AST_LOCALPARAM,
  53                 AST_PARASET,
  54                 AST_ARGUMENT,
  55                 AST_RANGE,
  56                 AST_CONSTANT,
  57                 AST_CELLTYPE,
  58                 AST_IDENTIFIER,
  59                 AST_PREFIX,
  60
  61                 AST_FCALL,
  62                 AST_TO_SIGNED,
  63                 AST_TO_UNSIGNED,
  64                 AST_CONCAT,
  65                 AST_REPLICATE,
  66                 AST_BIT_NOT,
  67                 AST_BIT_AND,
  68                 AST_BIT_OR,
  69                 AST_BIT_XOR,
  70                 AST_BIT_XNOR,
  71                 AST_REDUCE_AND,
  72                 AST_REDUCE_OR,
  73                 AST_REDUCE_XOR,
  74                 AST_REDUCE_XNOR,
  75                 AST_REDUCE_BOOL,
  76                 AST_SHIFT_LEFT,
  77                 AST_SHIFT_RIGHT,
  78                 AST_SHIFT_SLEFT,
  79                 AST_SHIFT_SRIGHT,
  80                 AST_LT,
  81                 AST_LE,
  82                 AST_EQ,
  83                 AST_NE,
  84                 AST_GE,
  85                 AST_GT,
  86                 AST_ADD,
  87                 AST_SUB,
  88                 AST_MUL,
  89                 AST_DIV,
  90                 AST_MOD,
  91                 AST_POW,
  92                 AST_POS,
  93                 AST_NEG,
  94                 AST_LOGIC_AND,
  95                 AST_LOGIC_OR,
  96                 AST_LOGIC_NOT,
  97                 AST_TERNARY,
  98                 AST_MEMRD,
  99                 AST_MEMWR,
 100
 101                 AST_TCALL,
 102                 AST_ASSIGN,
 103                 AST_CELL,
 104                 AST_PRIMITIVE,
 105                 AST_ALWAYS,
 106                 AST_INITIAL,
 107                 AST_BLOCK,
 108                 AST_ASSIGN_EQ,
 109                 AST_ASSIGN_LE,
 110                 AST_CASE,
 111                 AST_COND,
 112                 AST_DEFAULT,
 113                 AST_FOR,
 114
 115                 AST_GENVAR,
 116                 AST_GENFOR,
 117                 AST_GENIF,
 118                 AST_GENBLOCK,
 119
 120                 AST_POSEDGE,
 121                 AST_NEGEDGE,
 122                 AST_EDGE
 123         };
 124
 125         // convert an node type to a string (e.g. for debug output)
 126         std::string type2str(AstNodeType type);
 127
 128         // The AST is built using instances of this struct
 129         struct AstNode
 130         {
 131                 // this nodes type
 132                 AstNodeType type;
 133
 134                 // the list of child nodes for this node
 135                 std::vector<AstNode*> children;
 136
 137                 // the list of attributes assigned to this node
 138                 std::map<RTLIL::IdString, AstNode*> attributes;
 139
 140                 // node content - most of it is unused in most node types
 141                 std::string str;
 142                 std::vector<RTLIL::State> bits;
 143                 bool is_input, is_output, is_reg, is_signed, range_valid;
 144                 int port_id, range_left, range_right;
 145                 uint32_t integer;
 146
 147                 // this is set by simplify and used during RTLIL generation
 148                 AstNode *id2ast;
 149
 150                 // this is the original sourcecode location that resulted in this AST node
 151                 // it is automatically set by the constructor using AST::current_filename and
 152                 // the AST::get_line_num() callback function.
 153                 std::string filename;
 154                 int linenum;
 155
 156                 // creating and deleting nodes
 157                 AstNode(AstNodeType type = AST_NONE, AstNode *child1 = NULL, AstNode *child2 = NULL);
 158                 AstNode *clone();
 159                 void cloneInto(AstNode *other);
 160                 void delete_children();
 161                 ~AstNode();
 162
 163                 // simplify() creates a simpler AST by unrolling for-loops, expanding generate blocks, etc.
 164                 // it also sets the id2ast pointers so that identifier lookups are fast in genRTLIL()
 165                 bool simplify(bool const_fold, bool at_zero, bool in_lvalue, int stage);
 166                 void expand_genblock(std::string index_var, std::string prefix, std::map<std::string, std::string> &name_map);
 167                 void replace_ids(std::map<std::string, std::string> &rules);
 168                 void mem2reg_as_needed_pass1(std::set<AstNode*> &mem2reg_set, std::set<AstNode*> &mem2reg_candidates, bool sync_proc, bool async_proc, bool force_mem2reg);
 169                 void mem2reg_as_needed_pass2(std::set<AstNode*> &mem2reg_set, AstNode *mod, AstNode *block);
 170                 void meminfo(int &mem_width, int &mem_size, int &addr_bits);
 171
 172                 // create a human-readable text representation of the AST (for debugging)
 173                 void dumpAst(FILE *f, std::string indent, AstNode *other = NULL);
 174                 void dumpVlog(FILE *f, std::string indent);
 175
 176                 // create RTLIL code for this AST node
 177                 // for expressions the resulting signal vector is returned
 178                 // all generated cell instances, etc. are written to the RTLIL::Module pointed to by AST_INTERNAL::current_module
 179                 RTLIL::SigSpec genRTLIL(int width_hint = -1);
 180                 RTLIL::SigSpec genWidthRTLIL(int width, RTLIL::SigSpec *subst_from = NULL,  RTLIL::SigSpec *subst_to = NULL);
 181
 182                 // compare AST nodes
 183                 bool operator==(const AstNode &other) const;
 184                 bool operator!=(const AstNode &other) const;
 185                 bool contains(const AstNode *other) const;
 186
 187                 // helper functions for creating AST nodes for constants
 188                 static AstNode *mkconst_int(uint32_t v, bool is_signed, int width = 32);
 189                 static AstNode *mkconst_bits(const std::vector<RTLIL::State> &v, bool is_signed);
 190         };
 191
 192         // process an AST tree (ast must point to an AST_DESIGN node) and generate RTLIL code
 193         void process(RTLIL::Design *design, AstNode *ast, bool dump_ast = false, bool dump_ast_diff = false, bool dump_vlog = false, bool nolatches = false, bool nomem2reg = false, bool mem2reg = false, bool lib = false);
 194
 195         // parametric modules are supported directly by the AST library
 196         // therfore we need our own derivate of RTLIL::Module with overloaded virtual functions
 197         struct AstModule : RTLIL::Module {
 198                 AstNode *ast;
 199                 bool nolatches, nomem2reg, mem2reg, lib;
 200                 virtual ~AstModule();
 201                 virtual RTLIL::IdString derive(RTLIL::Design *design, std::map<RTLIL::IdString, RTLIL::Const> parameters);
 202                 virtual void update_auto_wires(std::map<RTLIL::IdString, int> auto_sizes);
 203         };
 204
 205         // this must be set by the language frontend before parsing the sources
 206         // the AstNode constructor then uses current_filename and get_line_num()
 207         // to initialize the filename and linenum properties of new nodes
 208         extern std::string current_filename;
 209         extern void (*set_line_num)(int);
 210         extern int (*get_line_num)();
 211
 212         // set set_line_num and get_line_num to internal dummy functions
 213         // (done by simplify(), AstModule::derive and AstModule::update_auto_wires to control
 214         // the filename and linenum properties of new nodes not generated by a frontend parser)
 215         void use_internal_line_num();
 216 }
 217
 218 namespace AST_INTERNAL
 219 {
 220         // internal state variables
 221         extern bool flag_dump_ast, flag_dump_ast_diff, flag_nolatches, flag_nomem2reg, flag_mem2reg, flag_lib;
 222         extern AST::AstNode *current_ast, *current_ast_mod;
 223         extern std::map<std::string, AST::AstNode*> current_scope;
 224         extern RTLIL::SigSpec *genRTLIL_subst_from, *genRTLIL_subst_to, ignoreThisSignalsInInitial;
 225         extern AST::AstNode *current_top_block, *current_block, *current_block_child;
 226         extern AST::AstModule *current_module;
 227         struct ProcessGenerator;
 228 }
 229
 230 #endif