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>.
5 This file is part of GNU CC.
7 GNU CC is free software; you can redistribute it and/or modify
8 it under the terms of the GNU General Public License as published by
9 the Free Software Foundation; either version 2, or (at your option)
12 GNU CC is distributed in the hope that it will be useful,
13 but WITHOUT ANY WARRANTY; without even the implied warranty of
14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 GNU General Public License for more details.
17 You should have received a copy of the GNU General Public License
18 along with GNU CC; see the file COPYING. If not, write to
19 the Free Software Foundation, 59 Temple Place - Suite 330,
20 Boston, MA 02111-1307, USA. */
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
,
30 void compute_dominance_frontiers
PARAMS ((sbitmap
*frontiers
, int *idom
));
31 extern int remove_phi_alternative
PARAMS ((rtx
, basic_block
));
36 extern void ssa_eliminate_dead_code
PARAMS ((void));
39 extern void ssa_const_prop
PARAMS ((void));
42 /* SSA definitions and uses. */
43 /* This flag is set when the CFG is in SSA form. */
44 extern int in_ssa_form
;
46 /* Element I is the single instruction that sets register I. */
47 extern varray_type ssa_definition
;
49 /* Element I is an INSN_LIST of instructions that use register I. */
50 extern varray_type ssa_uses
;
53 /* Specify which hard registers should be converted. */
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. */
59 /* Given a hard register number REG_NO, return nonzero if and only if
60 the register should be converted to SSA. */
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 */
66 /* Given a register number REG_NO, return nonzero if and only if the
67 register should be converted to SSA. */
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)))