1 /* Mode switching cleanup pass for the EPIPHANY cpu. 2 Copyright (C) 2000-2013 Free Software Foundation, Inc. 3 Contributed by Embecosm on behalf of Adapteva, Inc. 4 5 This file is part of GCC. 6 7 GCC 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 3, or (at your option) 10 any later version. 11 12 GCC 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. 16 17 You should have received a copy of the GNU General Public License 18 along with GCC; see the file COPYING3. If not see 19 <http://www.gnu.org/licenses/>. */ 20 21 #include "config.h" 22 #include "system.h" 23 #include "coretypes.h" 24 #include "machmode.h" 25 #include "tm.h" 26 #include "hard-reg-set.h" 27 #include "tm_p.h" 28 #include "vec.h" 29 #include "sbitmap.h" 30 #include "basic-block.h" 31 #include "df.h" 32 #include "rtl.h" 33 #include "insn-config.h" 34 #include "insn-codes.h" 35 #include "emit-rtl.h" 36 #include "recog.h" 37 #include "function.h" 38 #include "insn-attr-common.h" 39 #include "tree-pass.h" 40 41 /* Clean-up after mode switching: 42 Check for mode setting insns that have FP_MODE_ROUND_UNKNOWN. 43 If only one rounding mode is required, select that one. 44 Else we have to choose one to use in this mode setting insn and 45 insert new mode setting insns on the edges where the other mode 46 becomes unambigous. */ 47 48 static bool 49 gate_resolve_sw_modes (void) 50 { 51 return optimize; 52 } 53 54 static unsigned 55 resolve_sw_modes (void) 56 { 57 basic_block bb; 58 rtx insn, src; 59 vec<basic_block> todo; 60 sbitmap pushed; 61 bool need_commit = false; 62 bool finalize_fp_sets = (MACHINE_FUNCTION (cfun)->unknown_mode_sets == 0); 63 64 todo.create (last_basic_block); 65 pushed = sbitmap_alloc (last_basic_block); 66 bitmap_clear (pushed); 67 if (!finalize_fp_sets) 68 { 69 df_note_add_problem (); 70 df_analyze (); 71 } 72 FOR_EACH_BB (bb) 73 FOR_BB_INSNS (bb, insn) 74 { 75 enum attr_fp_mode selected_mode; 76 77 if (!NONJUMP_INSN_P (insn) 78 || recog_memoized (insn) != CODE_FOR_set_fp_mode) 79 continue; 80 src = SET_SRC (XVECEXP (PATTERN (insn), 0, 0)); 81 if (finalize_fp_sets) 82 { 83 SET_SRC (XVECEXP (PATTERN (insn), 0, 2)) = copy_rtx (src); 84 if (REG_P (src)) 85 df_insn_rescan (insn); 86 continue; 87 } 88 if (REG_P (src) 89 || XINT (XVECEXP (XEXP (src, 0), 0, 0), 0) != FP_MODE_ROUND_UNKNOWN) 90 continue; 91 if (find_regno_note (insn, REG_UNUSED, FP_TRUNCATE_REGNUM)) 92 selected_mode = FP_MODE_ROUND_NEAREST; 93 else if (find_regno_note (insn, REG_UNUSED, FP_NEAREST_REGNUM)) 94 selected_mode = FP_MODE_ROUND_TRUNC; 95 else 96 { 97 /* We could get more fancy in the selection of the mode by 98 checking the total frequency of the affected edges. */ 99 selected_mode = (enum attr_fp_mode) epiphany_normal_fp_rounding; 100 101 todo.quick_push (bb); 102 bitmap_set_bit (pushed, bb->index); 103 } 104 XVECEXP (XEXP (src, 0), 0, 0) = GEN_INT (selected_mode); 105 SET_SRC (XVECEXP (PATTERN (insn), 0, 1)) = copy_rtx (src); 106 SET_SRC (XVECEXP (PATTERN (insn), 0, 2)) = copy_rtx (src); 107 df_insn_rescan (insn); 108 } 109 while (todo.length ()) 110 { 111 basic_block bb = todo.pop (); 112 int selected_reg, jilted_reg; 113 enum attr_fp_mode jilted_mode; 114 edge e; 115 edge_iterator ei; 116 117 bitmap_set_bit (pushed, bb->index); 118 bitmap_set_bit (pushed, bb->index); 119 120 if (epiphany_normal_fp_rounding == FP_MODE_ROUND_NEAREST) 121 { 122 selected_reg = FP_NEAREST_REGNUM; 123 jilted_reg = FP_TRUNCATE_REGNUM; 124 jilted_mode = FP_MODE_ROUND_TRUNC; 125 } 126 else 127 { 128 selected_reg = FP_TRUNCATE_REGNUM; 129 jilted_reg = FP_NEAREST_REGNUM; 130 jilted_mode = FP_MODE_ROUND_NEAREST; 131 } 132 133 FOR_EACH_EDGE (e, ei, bb->succs) 134 { 135 basic_block succ = e->dest; 136 rtx seq; 137 138 if (!REGNO_REG_SET_P (DF_LIVE_IN (succ), jilted_reg)) 139 continue; 140 if (REGNO_REG_SET_P (DF_LIVE_IN (succ), selected_reg)) 141 { 142 if (bitmap_bit_p (pushed, succ->index)) 143 continue; 144 todo.quick_push (succ); 145 bitmap_set_bit (pushed, bb->index); 146 continue; 147 } 148 start_sequence (); 149 emit_set_fp_mode (EPIPHANY_MSW_ENTITY_ROUND_UNKNOWN, 150 jilted_mode, NULL); 151 seq = get_insns (); 152 end_sequence (); 153 need_commit = true; 154 insert_insn_on_edge (seq, e); 155 } 156 } 157 todo.release (); 158 sbitmap_free (pushed); 159 if (need_commit) 160 commit_edge_insertions (); 161 return 0; 162 } 163 164 struct rtl_opt_pass pass_resolve_sw_modes = 165 { 166 { 167 RTL_PASS, 168 "resolve_sw_modes", /* name */ 169 OPTGROUP_NONE, /* optinfo_flags */ 170 gate_resolve_sw_modes, /* gate */ 171 resolve_sw_modes, /* execute */ 172 NULL, /* sub */ 173 NULL, /* next */ 174 0, /* static_pass_number */ 175 TV_MODE_SWITCH, /* tv_id */ 176 0, /* properties_required */ 177 0, /* properties_provided */ 178 0, /* properties_destroyed */ 179 0, /* todo_flags_start */ 180 TODO_df_finish | TODO_verify_rtl_sharing | 181 0 /* todo_flags_finish */ 182 } 183 }; 184