gcc/ssa.h

   1 /* Static Single Assignment (SSA) definitions for GNU C-Compiler
   2    Copyright (C) 2000, 2001 Free Software Foundation, Inc.
   3    Written by Jeffrey D. Oldham <oldham@codesourcery.com>.
   4
   5 This file is part of GCC.
   6
   7 GCC is free software; you can redistribute it and/or modify it under
   8 the terms of the GNU General Public License as published by the Free
   9 Software Foundation; either version 2, or (at your option) any later
  10 version.
  11
  12 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
  13 WARRANTY; without even the implied warranty of MERCHANTABILITY or
  14 FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  15 for more details.
  16
  17 You should have received a copy of the GNU General Public License
  18 along with GCC; see the file COPYING.  If not, write to the Free
  19 Software Foundation, 59 Temple Place - Suite 330, Boston, MA
  20 02111-1307, USA.  */
  21
  22
  23 /* Main SSA routines.  */
  24 extern void convert_to_ssa              PARAMS ((void));
  25 extern void convert_from_ssa            PARAMS ((void));
  26 typedef int (*successor_phi_fn)         PARAMS ((rtx, int, int, void *));
  27 extern int for_each_successor_phi       PARAMS ((basic_block bb,
  28                                                  successor_phi_fn,
  29                                                  void *));
  30 void compute_dominance_frontiers        PARAMS ((sbitmap *frontiers, int *idom));
  31 extern int remove_phi_alternative       PARAMS ((rtx, basic_block));
  32
  33
  34 /* Optimizations.  */
  35 /* In ssa-dce.c */
  36 extern void ssa_eliminate_dead_code     PARAMS ((void));
  37
  38 /* In ssa-ccp.c */
  39 extern void ssa_const_prop              PARAMS ((void));
  40
  41
  42 /* SSA definitions and uses.  */
  43 /* This flag is set when the CFG is in SSA form.  */
  44 extern int in_ssa_form;
  45
  46 /* Element I is the single instruction that sets register I.  */
  47 extern varray_type ssa_definition;
  48
  49 /* Element I is an INSN_LIST of instructions that use register I.  */
  50 extern varray_type ssa_uses;
  51
  52
  53 /* Specify which hard registers should be converted.  */
  54
  55 /* All pseudo-registers (having register number >=
  56    FIRST_PSEUDO_REGISTER) and hard registers satisfying
  57    CONVERT_HARD_REGISTER_TO_SSA_P are converted to SSA form.  */
  58
  59 /* Given a hard register number REG_NO, return nonzero if and only if
  60    the register should be converted to SSA.  */
  61
  62 #ifndef CONVERT_HARD_REGISTER_TO_SSA_P
  63 #define CONVERT_HARD_REGISTER_TO_SSA_P(REG_NO) (0) /* default of no hard registers */
  64 #endif /* CONVERT_HARD_REGISTER_TO_SSA_P  */
  65
  66 /* Given a register number REG_NO, return nonzero if and only if the
  67    register should be converted to SSA.  */
  68
  69 #define CONVERT_REGISTER_TO_SSA_P(REG_NO)       \
  70         ((!HARD_REGISTER_NUM_P (REG_NO)) || \
  71          (CONVERT_HARD_REGISTER_TO_SSA_P (REG_NO)))