1 | /* Calculate branch probabilities, and basic block execution counts. |
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2 | Copyright (C) 1990, 91-94, 96, 97, 1998 Free Software Foundation, Inc. |
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3 | Contributed by James E. Wilson, UC Berkeley/Cygnus Support; |
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4 | based on some ideas from Dain Samples of UC Berkeley. |
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5 | Further mangling by Bob Manson, Cygnus Support. |
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6 | |
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7 | This file is part of GNU CC. |
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8 | |
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9 | GNU CC is free software; you can redistribute it and/or modify |
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10 | it under the terms of the GNU General Public License as published by |
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11 | the Free Software Foundation; either version 2, or (at your option) |
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12 | any later version. |
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13 | |
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14 | GNU CC is distributed in the hope that it will be useful, |
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15 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
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16 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
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17 | GNU General Public License for more details. |
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18 | |
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19 | You should have received a copy of the GNU General Public License |
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20 | along with GNU CC; see the file COPYING. If not, write to |
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21 | the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA. */ |
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22 | |
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23 | /* ??? Really should not put insns inside of LIBCALL sequences, when putting |
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24 | insns after a call, should look for the insn setting the retval, and |
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25 | insert the insns after that one. */ |
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26 | |
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27 | /* ??? Register allocation should use basic block execution counts to |
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28 | give preference to the most commonly executed blocks. */ |
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29 | |
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30 | /* ??? The .da files are not safe. Changing the program after creating .da |
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31 | files or using different options when compiling with -fbranch-probabilities |
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32 | can result the arc data not matching the program. Maybe add instrumented |
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33 | arc count to .bbg file? Maybe check whether PFG matches the .bbg file? */ |
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34 | |
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35 | /* ??? Should calculate branch probabilities before instrumenting code, since |
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36 | then we can use arc counts to help decide which arcs to instrument. */ |
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37 | |
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38 | /* ??? Rearrange code so that the most frequently executed arcs become from |
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39 | one block to the next block (i.e. a fall through), move seldom executed |
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40 | code outside of loops even at the expense of adding a few branches to |
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41 | achieve this, see Dain Sample's UC Berkeley thesis. */ |
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42 | |
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43 | #include "config.h" |
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44 | #include <stdio.h> |
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45 | #include "rtl.h" |
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46 | #include "flags.h" |
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47 | #include "insn-flags.h" |
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48 | #include "insn-config.h" |
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49 | #include "output.h" |
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50 | #include "regs.h" |
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51 | #include "tree.h" |
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52 | #include "output.h" |
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53 | #include "gcov-io.h" |
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54 | |
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55 | extern char * xmalloc (); |
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56 | extern void free (); |
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57 | |
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58 | /* One of these is dynamically created whenever we identify an arc in the |
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59 | function. */ |
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60 | |
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61 | struct adj_list |
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62 | { |
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63 | int source; |
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64 | int target; |
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65 | int arc_count; |
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66 | unsigned int count_valid : 1; |
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67 | unsigned int on_tree : 1; |
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68 | unsigned int fake : 1; |
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69 | unsigned int fall_through : 1; |
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70 | rtx branch_insn; |
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71 | struct adj_list *pred_next; |
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72 | struct adj_list *succ_next; |
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73 | }; |
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74 | |
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75 | #define ARC_TARGET(ARCPTR) (ARCPTR->target) |
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76 | #define ARC_SOURCE(ARCPTR) (ARCPTR->source) |
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77 | #define ARC_COUNT(ARCPTR) (ARCPTR->arc_count) |
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78 | |
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79 | /* Count the number of basic blocks, and create an array of these structures, |
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80 | one for each bb in the function. */ |
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81 | |
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82 | struct bb_info |
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83 | { |
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84 | struct adj_list *succ; |
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85 | struct adj_list *pred; |
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86 | int succ_count; |
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87 | int pred_count; |
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88 | int exec_count; |
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89 | unsigned int count_valid : 1; |
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90 | unsigned int on_tree : 1; |
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91 | rtx first_insn; |
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92 | }; |
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93 | |
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94 | /* Indexed by label number, gives the basic block number containing that |
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95 | label. */ |
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96 | |
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97 | static int *label_to_bb; |
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98 | |
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99 | /* Number of valid entries in the label_to_bb array. */ |
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100 | |
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101 | static int label_to_bb_size; |
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102 | |
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103 | /* Indexed by block index, holds the basic block graph. */ |
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104 | |
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105 | static struct bb_info *bb_graph; |
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106 | |
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107 | /* Name and file pointer of the output file for the basic block graph. */ |
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108 | |
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109 | static char *bbg_file_name; |
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110 | static FILE *bbg_file; |
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111 | |
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112 | /* Name and file pointer of the input file for the arc count data. */ |
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113 | |
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114 | static char *da_file_name; |
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115 | static FILE *da_file; |
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116 | |
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117 | /* Pointer of the output file for the basic block/line number map. */ |
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118 | static FILE *bb_file; |
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119 | |
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120 | /* Last source file name written to bb_file. */ |
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121 | |
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122 | static char *last_bb_file_name; |
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123 | |
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124 | /* Indicates whether the next line number note should be output to |
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125 | bb_file or not. Used to eliminate a redundant note after an |
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126 | expanded inline function call. */ |
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127 | |
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128 | static int ignore_next_note; |
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129 | |
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130 | /* Used by final, for allocating the proper amount of storage for the |
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131 | instrumented arc execution counts. */ |
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132 | |
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133 | int count_instrumented_arcs; |
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134 | |
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135 | /* Number of executions for the return label. */ |
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136 | |
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137 | int return_label_execution_count; |
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138 | |
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139 | /* Collect statistics on the performance of this pass for the entire source |
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140 | file. */ |
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141 | |
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142 | static int total_num_blocks; |
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143 | static int total_num_arcs; |
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144 | static int total_num_arcs_instrumented; |
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145 | static int total_num_blocks_created; |
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146 | static int total_num_passes; |
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147 | static int total_num_times_called; |
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148 | static int total_hist_br_prob[20]; |
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149 | static int total_num_never_executed; |
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150 | static int total_num_branches; |
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151 | |
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152 | /* Forward declarations. */ |
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153 | static void init_arc PROTO((struct adj_list *, int, int, rtx)); |
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154 | static void find_spanning_tree PROTO((int)); |
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155 | static void expand_spanning_tree PROTO((int)); |
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156 | static void fill_spanning_tree PROTO((int)); |
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157 | static void init_arc_profiler PROTO((void)); |
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158 | static void output_arc_profiler PROTO((int, rtx)); |
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159 | |
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160 | #ifndef LONG_TYPE_SIZE |
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161 | #define LONG_TYPE_SIZE BITS_PER_WORD |
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162 | #endif |
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163 | |
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164 | /* If non-zero, we need to output a constructor to set up the |
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165 | per-object-file data. */ |
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166 | static int need_func_profiler = 0; |
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167 | |
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168 | |
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169 | /* Add arc instrumentation code to the entire insn chain. |
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170 | |
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171 | F is the first insn of the chain. |
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172 | NUM_BLOCKS is the number of basic blocks found in F. |
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173 | DUMP_FILE, if nonzero, is an rtl dump file we can write to. */ |
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174 | |
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175 | static void |
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176 | instrument_arcs (f, num_blocks, dump_file) |
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177 | rtx f; |
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178 | int num_blocks; |
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179 | FILE *dump_file; |
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180 | { |
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181 | register int i; |
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182 | register struct adj_list *arcptr, *backptr; |
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183 | int num_arcs = 0; |
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184 | int num_instr_arcs = 0; |
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185 | rtx insn; |
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186 | |
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187 | int neg_one = -1; |
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188 | int zero = 0; |
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189 | int inverted; |
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190 | rtx note; |
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191 | |
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192 | /* Instrument the program start. */ |
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193 | /* Handle block 0 specially, since it will always be instrumented, |
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194 | but it doesn't have a valid first_insn or branch_insn. We must |
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195 | put the instructions before the NOTE_INSN_FUNCTION_BEG note, so |
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196 | that they don't clobber any of the parameters of the current |
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197 | function. */ |
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198 | for (insn = f; insn; insn = NEXT_INSN (insn)) |
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199 | if (GET_CODE (insn) == NOTE |
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200 | && NOTE_LINE_NUMBER (insn) == NOTE_INSN_FUNCTION_BEG) |
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201 | break; |
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202 | insn = PREV_INSN (insn); |
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203 | need_func_profiler = 1; |
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204 | output_arc_profiler (total_num_arcs_instrumented + num_instr_arcs++, insn); |
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205 | |
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206 | for (i = 1; i < num_blocks; i++) |
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207 | for (arcptr = bb_graph[i].succ; arcptr; arcptr = arcptr->succ_next) |
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208 | if (! arcptr->on_tree) |
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209 | { |
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210 | if (dump_file) |
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211 | fprintf (dump_file, "Arc %d to %d instrumented\n", i, |
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212 | ARC_TARGET (arcptr)); |
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213 | |
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214 | /* Check to see if this arc is the only exit from its source block, |
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215 | or the only entrance to its target block. In either case, |
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216 | we don't need to create a new block to instrument the arc. */ |
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217 | |
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218 | if (bb_graph[i].succ == arcptr && arcptr->succ_next == 0) |
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219 | { |
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220 | /* Instrument the source block. */ |
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221 | output_arc_profiler (total_num_arcs_instrumented |
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222 | + num_instr_arcs++, |
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223 | PREV_INSN (bb_graph[i].first_insn)); |
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224 | } |
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225 | else if (arcptr == bb_graph[ARC_TARGET (arcptr)].pred |
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226 | && arcptr->pred_next == 0) |
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227 | { |
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228 | /* Instrument the target block. */ |
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229 | output_arc_profiler (total_num_arcs_instrumented |
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230 | + num_instr_arcs++, |
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231 | PREV_INSN (bb_graph[ARC_TARGET (arcptr)].first_insn)); |
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232 | } |
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233 | else if (arcptr->fall_through) |
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234 | { |
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235 | /* This is a fall-through; put the instrumentation code after |
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236 | the branch that ends this block. */ |
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237 | |
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238 | for (backptr = bb_graph[i].succ; backptr; |
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239 | backptr = backptr->succ_next) |
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240 | if (backptr != arcptr) |
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241 | break; |
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242 | |
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243 | output_arc_profiler (total_num_arcs_instrumented |
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244 | + num_instr_arcs++, |
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245 | backptr->branch_insn); |
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246 | } |
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247 | else |
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248 | { |
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249 | /* Must emit a new basic block to hold the arc counting code. */ |
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250 | enum rtx_code code = GET_CODE (PATTERN (arcptr->branch_insn)); |
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251 | |
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252 | if (code == SET) |
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253 | { |
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254 | /* Create the new basic block right after the branch. |
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255 | Invert the branch so that it jumps past the end of the new |
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256 | block. The new block will consist of the instrumentation |
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257 | code, and a jump to the target of this arc. */ |
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258 | int this_is_simplejump = simplejump_p (arcptr->branch_insn); |
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259 | rtx new_label = gen_label_rtx (); |
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260 | rtx old_label, set_src; |
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261 | rtx after = arcptr->branch_insn; |
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262 | |
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263 | /* Simplejumps can't reach here. */ |
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264 | if (this_is_simplejump) |
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265 | abort (); |
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266 | |
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267 | /* We can't use JUMP_LABEL, because it won't be set if we |
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268 | are compiling without optimization. */ |
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269 | |
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270 | set_src = SET_SRC (single_set (arcptr->branch_insn)); |
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271 | if (GET_CODE (set_src) == LABEL_REF) |
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272 | old_label = set_src; |
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273 | else if (GET_CODE (set_src) != IF_THEN_ELSE) |
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274 | abort (); |
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275 | else if (XEXP (set_src, 1) == pc_rtx) |
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276 | old_label = XEXP (XEXP (set_src, 2), 0); |
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277 | else |
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278 | old_label = XEXP (XEXP (set_src, 1), 0); |
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279 | |
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280 | /* Set the JUMP_LABEL so that redirect_jump will work. */ |
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281 | JUMP_LABEL (arcptr->branch_insn) = old_label; |
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282 | |
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283 | /* Add a use for OLD_LABEL that will be needed when we emit |
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284 | the JUMP_INSN below. If we don't do this here, |
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285 | `invert_jump' might delete it for us. We must add two |
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286 | when not optimizing, because the NUSES is zero now, |
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287 | but must be at least two to prevent the label from being |
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288 | deleted. */ |
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289 | LABEL_NUSES (old_label) += 2; |
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290 | |
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291 | /* Emit the insns for the new block in reverse order, |
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292 | since that is most convenient. */ |
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293 | |
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294 | if (this_is_simplejump) |
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295 | { |
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296 | after = NEXT_INSN (arcptr->branch_insn); |
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297 | if (! redirect_jump (arcptr->branch_insn, new_label)) |
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298 | /* Don't know what to do if this branch won't |
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299 | redirect. */ |
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300 | abort (); |
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301 | } |
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302 | else |
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303 | { |
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304 | if (! invert_jump (arcptr->branch_insn, new_label)) |
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305 | /* Don't know what to do if this branch won't invert. */ |
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306 | abort (); |
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307 | |
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308 | emit_label_after (new_label, after); |
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309 | LABEL_NUSES (new_label)++; |
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310 | } |
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311 | emit_barrier_after (after); |
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312 | emit_jump_insn_after (gen_jump (old_label), after); |
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313 | JUMP_LABEL (NEXT_INSN (after)) = old_label; |
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314 | |
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315 | /* Instrument the source arc. */ |
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316 | output_arc_profiler (total_num_arcs_instrumented |
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317 | + num_instr_arcs++, |
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318 | after); |
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319 | if (this_is_simplejump) |
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320 | { |
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321 | emit_label_after (new_label, after); |
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322 | LABEL_NUSES (new_label)++; |
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323 | } |
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324 | } |
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325 | else if (code == ADDR_VEC || code == ADDR_DIFF_VEC) |
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326 | { |
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327 | /* A table jump. Create a new basic block immediately |
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328 | after the table, by emitting a barrier, a label, a |
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329 | counting note, and a jump to the old label. Put the |
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330 | new label in the table. */ |
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331 | |
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332 | rtx new_label = gen_label_rtx (); |
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333 | rtx old_lref, new_lref; |
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334 | int index; |
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335 | |
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336 | /* Must determine the old_label reference, do this |
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337 | by counting the arcs after this one, which will |
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338 | give the index of our label in the table. */ |
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339 | |
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340 | index = 0; |
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341 | for (backptr = arcptr->succ_next; backptr; |
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342 | backptr = backptr->succ_next) |
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343 | index++; |
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344 | |
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345 | old_lref = XVECEXP (PATTERN (arcptr->branch_insn), |
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346 | (code == ADDR_DIFF_VEC), index); |
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347 | |
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348 | /* Emit the insns for the new block in reverse order, |
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349 | since that is most convenient. */ |
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350 | emit_jump_insn_after (gen_jump (XEXP (old_lref, 0)), |
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351 | arcptr->branch_insn); |
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352 | JUMP_LABEL (NEXT_INSN (arcptr->branch_insn)) |
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353 | = XEXP (old_lref, 0); |
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354 | |
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355 | /* Instrument the source arc. */ |
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356 | output_arc_profiler (total_num_arcs_instrumented |
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357 | + num_instr_arcs++, |
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358 | arcptr->branch_insn); |
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359 | |
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360 | emit_label_after (new_label, arcptr->branch_insn); |
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361 | LABEL_NUSES (NEXT_INSN (arcptr->branch_insn))++; |
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362 | emit_barrier_after (arcptr->branch_insn); |
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363 | |
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364 | /* Fix up the table jump. */ |
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365 | new_lref = gen_rtx (LABEL_REF, Pmode, new_label); |
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366 | XVECEXP (PATTERN (arcptr->branch_insn), |
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367 | (code == ADDR_DIFF_VEC), index) = new_lref; |
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368 | } |
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369 | else |
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370 | abort (); |
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371 | |
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372 | num_arcs += 1; |
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373 | if (dump_file) |
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374 | fprintf (dump_file, |
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375 | "Arc %d to %d needed new basic block\n", i, |
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376 | ARC_TARGET (arcptr)); |
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377 | } |
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378 | } |
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379 | |
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380 | total_num_arcs_instrumented += num_instr_arcs; |
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381 | count_instrumented_arcs = total_num_arcs_instrumented; |
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382 | |
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383 | total_num_blocks_created += num_arcs; |
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384 | if (dump_file) |
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385 | { |
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386 | fprintf (dump_file, "%d arcs instrumented\n", num_instr_arcs); |
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387 | fprintf (dump_file, "%d extra basic blocks created\n", num_arcs); |
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388 | } |
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389 | } |
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390 | |
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391 | /* Output STRING to bb_file, surrounded by DELIMITER. */ |
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392 | |
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393 | static void |
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394 | output_gcov_string (string, delimiter) |
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395 | char *string; |
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396 | long delimiter; |
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397 | { |
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398 | long temp; |
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399 | |
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400 | /* Write a delimiter to indicate that a file name follows. */ |
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401 | __write_long (delimiter, bb_file, 4); |
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402 | |
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403 | /* Write the string. */ |
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404 | temp = strlen (string) + 1; |
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405 | fwrite (string, temp, 1, bb_file); |
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406 | |
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407 | /* Append a few zeros, to align the output to a 4 byte boundary. */ |
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408 | temp = temp & 0x3; |
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409 | if (temp) |
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410 | { |
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411 | char c[4]; |
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412 | |
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413 | c[0] = c[1] = c[2] = c[3] = 0; |
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414 | fwrite (c, sizeof (char), 4 - temp, bb_file); |
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415 | } |
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416 | |
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417 | /* Store another delimiter in the .bb file, just to make it easy to find the |
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418 | end of the file name. */ |
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419 | __write_long (delimiter, bb_file, 4); |
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420 | } |
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421 | |
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422 | /* Instrument and/or analyze program behavior based on program flow graph. |
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423 | In either case, this function builds a flow graph for the function being |
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424 | compiled. The flow graph is stored in BB_GRAPH. |
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425 | |
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426 | When FLAG_PROFILE_ARCS is nonzero, this function instruments the arcs in |
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427 | the flow graph that are needed to reconstruct the dynamic behavior of the |
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428 | flow graph. |
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429 | |
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430 | When FLAG_BRANCH_PROBABILITIES is nonzero, this function reads auxiliary |
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431 | information from a data file containing arc count information from previous |
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432 | executions of the function being compiled. In this case, the flow graph is |
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433 | annotated with actual execution counts, which are later propagated into the |
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434 | rtl for optimization purposes. |
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435 | |
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436 | Main entry point of this file. */ |
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437 | |
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438 | void |
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439 | branch_prob (f, dump_file) |
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440 | rtx f; |
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441 | FILE *dump_file; |
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442 | { |
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443 | int i, num_blocks; |
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444 | int dest; |
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445 | rtx insn; |
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446 | struct adj_list *arcptr; |
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447 | int num_arcs, changes, passes; |
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448 | int total, prob; |
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449 | int hist_br_prob[20], num_never_executed, num_branches; |
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450 | /* Set to non-zero if we got bad count information. */ |
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451 | int bad_counts = 0; |
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452 | |
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453 | /* start of a function. */ |
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454 | if (flag_test_coverage) |
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455 | output_gcov_string (current_function_name, (long) -2); |
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456 | |
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457 | /* Execute this only if doing arc profiling or branch probabilities. */ |
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458 | if (! profile_arc_flag && ! flag_branch_probabilities |
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459 | && ! flag_test_coverage) |
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460 | abort (); |
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461 | |
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462 | total_num_times_called++; |
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463 | |
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464 | /* Create an array label_to_bb of ints of size max_label_num. */ |
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465 | label_to_bb_size = max_label_num (); |
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466 | label_to_bb = (int *) oballoc (label_to_bb_size * sizeof (int)); |
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467 | bzero ((char *) label_to_bb, label_to_bb_size * sizeof (int)); |
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468 | |
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469 | /* Scan the insns in the function, count the number of basic blocks |
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470 | present. When a code label is passed, set label_to_bb[label] = bb |
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471 | number. */ |
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472 | |
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473 | /* The first block found will be block 1, so that function entry can be |
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474 | block 0. */ |
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475 | |
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476 | { |
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477 | register RTX_CODE prev_code = JUMP_INSN; |
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478 | register RTX_CODE code; |
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479 | register rtx insn; |
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480 | register int i; |
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481 | int block_separator_emitted = 0; |
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482 | |
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483 | ignore_next_note = 0; |
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484 | |
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485 | for (insn = NEXT_INSN (f), i = 0; insn; insn = NEXT_INSN (insn)) |
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486 | { |
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487 | code = GET_CODE (insn); |
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488 | |
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489 | if (code == BARRIER) |
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490 | ; |
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491 | else if (code == CODE_LABEL) |
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492 | /* This label is part of the next block, but we can't increment |
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493 | block number yet since there might be multiple labels. */ |
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494 | label_to_bb[CODE_LABEL_NUMBER (insn)] = i + 1; |
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495 | /* We make NOTE_INSN_SETJMP notes into a block of their own, so that |
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496 | they can be the target of the fake arc for the setjmp call. |
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497 | This avoids creating cycles of fake arcs, which would happen if |
---|
498 | the block after the setjmp call contained a call insn. */ |
---|
499 | else if ((prev_code == JUMP_INSN || prev_code == CALL_INSN |
---|
500 | || prev_code == CODE_LABEL || prev_code == BARRIER) |
---|
501 | && (GET_RTX_CLASS (code) == 'i' |
---|
502 | || (code == NOTE |
---|
503 | && NOTE_LINE_NUMBER (insn) == NOTE_INSN_SETJMP))) |
---|
504 | { |
---|
505 | i += 1; |
---|
506 | |
---|
507 | /* Emit the block separator if it hasn't already been emitted. */ |
---|
508 | if (flag_test_coverage && ! block_separator_emitted) |
---|
509 | { |
---|
510 | /* Output a zero to the .bb file to indicate that a new |
---|
511 | block list is starting. */ |
---|
512 | __write_long (0, bb_file, 4); |
---|
513 | } |
---|
514 | block_separator_emitted = 0; |
---|
515 | } |
---|
516 | /* If flag_test_coverage is true, then we must add an entry to the |
---|
517 | .bb file for every note. */ |
---|
518 | else if (code == NOTE && flag_test_coverage) |
---|
519 | { |
---|
520 | /* Must ignore the line number notes that immediately follow the |
---|
521 | end of an inline function to avoid counting it twice. There |
---|
522 | is a note before the call, and one after the call. */ |
---|
523 | if (NOTE_LINE_NUMBER (insn) == NOTE_REPEATED_LINE_NUMBER) |
---|
524 | ignore_next_note = 1; |
---|
525 | else if (NOTE_LINE_NUMBER (insn) > 0) |
---|
526 | { |
---|
527 | if (ignore_next_note) |
---|
528 | ignore_next_note = 0; |
---|
529 | else |
---|
530 | { |
---|
531 | /* Emit a block separator here to ensure that a NOTE |
---|
532 | immediately following a JUMP_INSN or CALL_INSN will end |
---|
533 | up in the right basic block list. */ |
---|
534 | if ((prev_code == JUMP_INSN || prev_code == CALL_INSN |
---|
535 | || prev_code == CODE_LABEL || prev_code == BARRIER) |
---|
536 | && ! block_separator_emitted) |
---|
537 | { |
---|
538 | /* Output a zero to the .bb file to indicate that |
---|
539 | a new block list is starting. */ |
---|
540 | __write_long (0, bb_file, 4); |
---|
541 | |
---|
542 | block_separator_emitted = 1; |
---|
543 | } |
---|
544 | |
---|
545 | /* If this is a new source file, then output the file's |
---|
546 | name to the .bb file. */ |
---|
547 | if (! last_bb_file_name |
---|
548 | || strcmp (NOTE_SOURCE_FILE (insn), |
---|
549 | last_bb_file_name)) |
---|
550 | { |
---|
551 | if (last_bb_file_name) |
---|
552 | free (last_bb_file_name); |
---|
553 | last_bb_file_name |
---|
554 | = xmalloc (strlen (NOTE_SOURCE_FILE (insn)) + 1); |
---|
555 | strcpy (last_bb_file_name, NOTE_SOURCE_FILE (insn)); |
---|
556 | output_gcov_string (NOTE_SOURCE_FILE (insn), (long)-1); |
---|
557 | } |
---|
558 | |
---|
559 | /* Output the line number to the .bb file. Must be done |
---|
560 | after the output_bb_profile_data() call, and after the |
---|
561 | file name is written, to ensure that it is correctly |
---|
562 | handled by gcov. */ |
---|
563 | __write_long (NOTE_LINE_NUMBER (insn), bb_file, 4); |
---|
564 | } |
---|
565 | } |
---|
566 | } |
---|
567 | |
---|
568 | if (code != NOTE) |
---|
569 | prev_code = code; |
---|
570 | else if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_SETJMP) |
---|
571 | prev_code = CALL_INSN; |
---|
572 | } |
---|
573 | |
---|
574 | /* Allocate last `normal' entry for bb_graph. */ |
---|
575 | |
---|
576 | /* The last insn was a jump, call, or label. In that case we have |
---|
577 | a block at the end of the function with no insns. */ |
---|
578 | if (prev_code == JUMP_INSN || prev_code == CALL_INSN |
---|
579 | || prev_code == CODE_LABEL || prev_code == BARRIER) |
---|
580 | { |
---|
581 | i++; |
---|
582 | |
---|
583 | /* Emit the block separator if it hasn't already been emitted. */ |
---|
584 | if (flag_test_coverage && ! block_separator_emitted) |
---|
585 | { |
---|
586 | /* Output a zero to the .bb file to indicate that a new |
---|
587 | block list is starting. */ |
---|
588 | __write_long (0, bb_file, 4); |
---|
589 | } |
---|
590 | } |
---|
591 | |
---|
592 | /* Create another block to stand for EXIT, and make all return insns, and |
---|
593 | the last basic block point here. Add one more to account for block |
---|
594 | zero. */ |
---|
595 | num_blocks = i + 2; |
---|
596 | } |
---|
597 | |
---|
598 | total_num_blocks += num_blocks; |
---|
599 | if (dump_file) |
---|
600 | fprintf (dump_file, "%d basic blocks\n", num_blocks); |
---|
601 | |
---|
602 | /* If we are only doing test coverage here, then return now. */ |
---|
603 | if (! profile_arc_flag && ! flag_branch_probabilities) |
---|
604 | return; |
---|
605 | |
---|
606 | /* Create and initialize the arrays that will hold bb_graph |
---|
607 | and execution count info. */ |
---|
608 | |
---|
609 | bb_graph = (struct bb_info *) alloca (num_blocks * sizeof (struct bb_info)); |
---|
610 | bzero ((char *) bb_graph, (sizeof (struct bb_info) * num_blocks)); |
---|
611 | |
---|
612 | { |
---|
613 | /* Scan the insns again: |
---|
614 | - at the entry to each basic block, increment the predecessor count |
---|
615 | (and successor of previous block) if it is a fall through entry, |
---|
616 | create adj_list entries for this and the previous block |
---|
617 | - at each jump insn, increment predecessor/successor counts for |
---|
618 | target/source basic blocks, add this insn to pred/succ lists. |
---|
619 | |
---|
620 | This also cannot be broken out as a separate subroutine |
---|
621 | because it uses `alloca'. */ |
---|
622 | |
---|
623 | register RTX_CODE prev_code = JUMP_INSN; |
---|
624 | register RTX_CODE code; |
---|
625 | register rtx insn; |
---|
626 | register int i; |
---|
627 | int fall_through = 0; |
---|
628 | struct adj_list *arcptr; |
---|
629 | int dest; |
---|
630 | |
---|
631 | /* Block 0 always falls through to block 1. */ |
---|
632 | num_arcs = 0; |
---|
633 | arcptr = (struct adj_list *) alloca (sizeof (struct adj_list)); |
---|
634 | init_arc (arcptr, 0, 1, 0); |
---|
635 | arcptr->fall_through = 1; |
---|
636 | num_arcs++; |
---|
637 | |
---|
638 | /* Add a fake fall through arc from the last block to block 0, to make the |
---|
639 | graph complete. */ |
---|
640 | arcptr = (struct adj_list *) alloca (sizeof (struct adj_list)); |
---|
641 | init_arc (arcptr, num_blocks - 1, 0, 0); |
---|
642 | arcptr->fake = 1; |
---|
643 | num_arcs++; |
---|
644 | |
---|
645 | /* Exit must be one node of the graph, and all exits from the function |
---|
646 | must point there. When see a return branch, must point the arc to the |
---|
647 | exit node. */ |
---|
648 | |
---|
649 | /* Must start scan with second insn in function as above. */ |
---|
650 | for (insn = NEXT_INSN (f), i = 0; insn; insn = NEXT_INSN (insn)) |
---|
651 | { |
---|
652 | code = GET_CODE (insn); |
---|
653 | |
---|
654 | if (code == BARRIER) |
---|
655 | fall_through = 0; |
---|
656 | else if (code == CODE_LABEL) |
---|
657 | ; |
---|
658 | /* We make NOTE_INSN_SETJMP notes into a block of their own, so that |
---|
659 | they can be the target of the fake arc for the setjmp call. |
---|
660 | This avoids creating cycles of fake arcs, which would happen if |
---|
661 | the block after the setjmp call ended with a call. */ |
---|
662 | else if ((prev_code == JUMP_INSN || prev_code == CALL_INSN |
---|
663 | || prev_code == CODE_LABEL || prev_code == BARRIER) |
---|
664 | && (GET_RTX_CLASS (code) == 'i' |
---|
665 | || (code == NOTE |
---|
666 | && NOTE_LINE_NUMBER (insn) == NOTE_INSN_SETJMP))) |
---|
667 | { |
---|
668 | /* This is the first insn of the block. */ |
---|
669 | i += 1; |
---|
670 | if (fall_through) |
---|
671 | { |
---|
672 | arcptr = (struct adj_list *) alloca (sizeof (struct adj_list)); |
---|
673 | init_arc (arcptr, i - 1, i, 0); |
---|
674 | arcptr->fall_through = 1; |
---|
675 | |
---|
676 | num_arcs++; |
---|
677 | } |
---|
678 | fall_through = 1; |
---|
679 | bb_graph[i].first_insn = insn; |
---|
680 | } |
---|
681 | else if (code == NOTE) |
---|
682 | ; |
---|
683 | |
---|
684 | if (code == CALL_INSN) |
---|
685 | { |
---|
686 | /* In the normal case, the call returns, and this is just like |
---|
687 | a branch fall through. */ |
---|
688 | fall_through = 1; |
---|
689 | |
---|
690 | /* Setjmp may return more times than called, so to make the graph |
---|
691 | solvable, add a fake arc from the function entrance to the |
---|
692 | next block. |
---|
693 | |
---|
694 | All other functions may return fewer times than called (if |
---|
695 | a descendent call longjmp or exit), so to make the graph |
---|
696 | solvable, add a fake arc to the function exit from the |
---|
697 | current block. |
---|
698 | |
---|
699 | Distinguish the cases by checking for a SETJUMP note. |
---|
700 | A call_insn can be the last ins of a function, so must check |
---|
701 | to see if next insn actually exists. */ |
---|
702 | arcptr = (struct adj_list *) alloca (sizeof (struct adj_list)); |
---|
703 | if (NEXT_INSN (insn) |
---|
704 | && GET_CODE (NEXT_INSN (insn)) == NOTE |
---|
705 | && NOTE_LINE_NUMBER (NEXT_INSN (insn)) == NOTE_INSN_SETJMP) |
---|
706 | init_arc (arcptr, 0, i+1, insn); |
---|
707 | else |
---|
708 | init_arc (arcptr, i, num_blocks-1, insn); |
---|
709 | arcptr->fake = 1; |
---|
710 | num_arcs++; |
---|
711 | } |
---|
712 | else if (code == JUMP_INSN) |
---|
713 | { |
---|
714 | rtx tem, pattern = PATTERN (insn); |
---|
715 | rtx tablejump = 0; |
---|
716 | |
---|
717 | /* If running without optimization, then jump label won't be valid, |
---|
718 | so we must search for the destination label in that case. |
---|
719 | We have to handle tablejumps and returns specially anyways, so |
---|
720 | we don't check the JUMP_LABEL at all here. */ |
---|
721 | |
---|
722 | if (GET_CODE (pattern) == PARALLEL) |
---|
723 | { |
---|
724 | /* This assumes that PARALLEL jumps are tablejump entry |
---|
725 | jumps. */ |
---|
726 | /* Make an arc from this jump to the label of the |
---|
727 | jump table. This will instrument the number of |
---|
728 | times the switch statement is executed. */ |
---|
729 | if (GET_CODE (XVECEXP (pattern, 0, 1)) == USE) |
---|
730 | { |
---|
731 | tem = XEXP (XVECEXP (pattern, 0, 1), 0); |
---|
732 | if (GET_CODE (tem) != LABEL_REF) |
---|
733 | abort (); |
---|
734 | dest = label_to_bb[CODE_LABEL_NUMBER (XEXP (tem, 0))]; |
---|
735 | } |
---|
736 | else if (GET_CODE (XVECEXP (pattern, 0, 0)) == SET |
---|
737 | && SET_DEST (XVECEXP (pattern, 0, 0)) == pc_rtx) |
---|
738 | { |
---|
739 | tem = SET_SRC (XVECEXP (pattern, 0, 0)); |
---|
740 | if (GET_CODE (tem) == PLUS |
---|
741 | && GET_CODE (XEXP (tem, 1)) == LABEL_REF) |
---|
742 | { |
---|
743 | tem = XEXP (tem, 1); |
---|
744 | dest = label_to_bb [CODE_LABEL_NUMBER (XEXP (tem, 0))]; |
---|
745 | } |
---|
746 | } |
---|
747 | else |
---|
748 | abort (); |
---|
749 | } |
---|
750 | else if (GET_CODE (pattern) == ADDR_VEC |
---|
751 | || GET_CODE (pattern) == ADDR_DIFF_VEC) |
---|
752 | tablejump = pattern; |
---|
753 | else if (GET_CODE (pattern) == RETURN) |
---|
754 | dest = num_blocks - 1; |
---|
755 | else if ((tem = SET_SRC (pattern)) |
---|
756 | && GET_CODE (tem) == LABEL_REF) |
---|
757 | dest = label_to_bb[CODE_LABEL_NUMBER (XEXP (tem, 0))]; |
---|
758 | else |
---|
759 | { |
---|
760 | rtx label_ref; |
---|
761 | |
---|
762 | /* Must be an IF_THEN_ELSE branch. */ |
---|
763 | if (GET_CODE (tem) != IF_THEN_ELSE) |
---|
764 | abort (); |
---|
765 | if (XEXP (tem, 1) != pc_rtx) |
---|
766 | label_ref = XEXP (tem, 1); |
---|
767 | else |
---|
768 | label_ref = XEXP (tem, 2); |
---|
769 | dest = label_to_bb[CODE_LABEL_NUMBER (XEXP (label_ref, 0))]; |
---|
770 | } |
---|
771 | |
---|
772 | if (tablejump) |
---|
773 | { |
---|
774 | int diff_vec_p = GET_CODE (tablejump) == ADDR_DIFF_VEC; |
---|
775 | int len = XVECLEN (tablejump, diff_vec_p); |
---|
776 | int k; |
---|
777 | |
---|
778 | for (k = 0; k < len; k++) |
---|
779 | { |
---|
780 | rtx tem = XEXP (XVECEXP (tablejump, diff_vec_p, k), 0); |
---|
781 | dest = label_to_bb[CODE_LABEL_NUMBER (tem)]; |
---|
782 | |
---|
783 | arcptr = (struct adj_list *) alloca (sizeof(struct adj_list)); |
---|
784 | init_arc (arcptr, i, dest, insn); |
---|
785 | |
---|
786 | num_arcs++; |
---|
787 | } |
---|
788 | } |
---|
789 | else |
---|
790 | { |
---|
791 | arcptr = (struct adj_list *) alloca (sizeof (struct adj_list)); |
---|
792 | init_arc (arcptr, i, dest, insn); |
---|
793 | |
---|
794 | num_arcs++; |
---|
795 | } |
---|
796 | |
---|
797 | /* Determine whether or not this jump will fall through. |
---|
798 | Unconditional jumps and returns are not always followed by |
---|
799 | barriers. */ |
---|
800 | pattern = PATTERN (insn); |
---|
801 | if (GET_CODE (pattern) == PARALLEL |
---|
802 | || GET_CODE (pattern) == RETURN) |
---|
803 | fall_through = 0; |
---|
804 | else if (GET_CODE (pattern) == ADDR_VEC |
---|
805 | || GET_CODE (pattern) == ADDR_DIFF_VEC) |
---|
806 | /* These aren't actually jump insns, but they never fall |
---|
807 | through, so... */ |
---|
808 | fall_through = 0; |
---|
809 | else |
---|
810 | { |
---|
811 | if (GET_CODE (pattern) != SET || SET_DEST (pattern) != pc_rtx) |
---|
812 | abort (); |
---|
813 | if (GET_CODE (SET_SRC (pattern)) != IF_THEN_ELSE) |
---|
814 | fall_through = 0; |
---|
815 | } |
---|
816 | } |
---|
817 | |
---|
818 | if (code != NOTE) |
---|
819 | prev_code = code; |
---|
820 | else if (NOTE_LINE_NUMBER (insn) == NOTE_INSN_SETJMP) |
---|
821 | prev_code = CALL_INSN; |
---|
822 | } |
---|
823 | |
---|
824 | /* If the code at the end of the function would give a new block, then |
---|
825 | do the following. */ |
---|
826 | |
---|
827 | if (prev_code == JUMP_INSN || prev_code == CALL_INSN |
---|
828 | || prev_code == CODE_LABEL || prev_code == BARRIER) |
---|
829 | { |
---|
830 | if (fall_through) |
---|
831 | { |
---|
832 | arcptr = (struct adj_list *) alloca (sizeof (struct adj_list)); |
---|
833 | init_arc (arcptr, i, i + 1, 0); |
---|
834 | arcptr->fall_through = 1; |
---|
835 | |
---|
836 | num_arcs++; |
---|
837 | } |
---|
838 | |
---|
839 | /* This may not be a real insn, but that should not cause a problem. */ |
---|
840 | bb_graph[i+1].first_insn = get_last_insn (); |
---|
841 | } |
---|
842 | |
---|
843 | /* There is always a fake arc from the last block of the function |
---|
844 | to the function exit block. */ |
---|
845 | arcptr = (struct adj_list *) alloca (sizeof (struct adj_list)); |
---|
846 | init_arc (arcptr, num_blocks-2, num_blocks-1, 0); |
---|
847 | arcptr->fake = 1; |
---|
848 | num_arcs++; |
---|
849 | } |
---|
850 | |
---|
851 | total_num_arcs += num_arcs; |
---|
852 | if (dump_file) |
---|
853 | fprintf (dump_file, "%d arcs\n", num_arcs); |
---|
854 | |
---|
855 | /* Create spanning tree from basic block graph, mark each arc that is |
---|
856 | on the spanning tree. */ |
---|
857 | |
---|
858 | /* To reduce the instrumentation cost, make two passes over the tree. |
---|
859 | First, put as many must-split (crowded and fake) arcs on the tree as |
---|
860 | possible, then on the second pass fill in the rest of the tree. |
---|
861 | Note that the spanning tree is considered undirected, so that as many |
---|
862 | must-split arcs as possible can be put on it. |
---|
863 | |
---|
864 | Fallthrough arcs which are crowded should not be chosen on the first |
---|
865 | pass, since they do not require creating a new basic block. These |
---|
866 | arcs will have fall_through set. */ |
---|
867 | |
---|
868 | find_spanning_tree (num_blocks); |
---|
869 | |
---|
870 | /* Create a .bbg file from which gcov can reconstruct the basic block |
---|
871 | graph. First output the number of basic blocks, and then for every |
---|
872 | arc output the source and target basic block numbers. |
---|
873 | NOTE: The format of this file must be compatible with gcov. */ |
---|
874 | |
---|
875 | if (flag_test_coverage) |
---|
876 | { |
---|
877 | int flag_bits; |
---|
878 | |
---|
879 | __write_long (num_blocks, bbg_file, 4); |
---|
880 | __write_long (num_arcs, bbg_file, 4); |
---|
881 | |
---|
882 | for (i = 0; i < num_blocks; i++) |
---|
883 | { |
---|
884 | long count = 0; |
---|
885 | for (arcptr = bb_graph[i].succ; arcptr; arcptr = arcptr->succ_next) |
---|
886 | count++; |
---|
887 | __write_long (count, bbg_file, 4); |
---|
888 | |
---|
889 | for (arcptr = bb_graph[i].succ; arcptr; arcptr = arcptr->succ_next) |
---|
890 | { |
---|
891 | flag_bits = 0; |
---|
892 | if (arcptr->on_tree) |
---|
893 | flag_bits |= 0x1; |
---|
894 | if (arcptr->fake) |
---|
895 | flag_bits |= 0x2; |
---|
896 | if (arcptr->fall_through) |
---|
897 | flag_bits |= 0x4; |
---|
898 | |
---|
899 | __write_long (ARC_TARGET (arcptr), bbg_file, 4); |
---|
900 | __write_long (flag_bits, bbg_file, 4); |
---|
901 | } |
---|
902 | } |
---|
903 | |
---|
904 | /* Emit a -1 to separate the list of all arcs from the list of |
---|
905 | loop back edges that follows. */ |
---|
906 | __write_long (-1, bbg_file, 4); |
---|
907 | } |
---|
908 | |
---|
909 | /* For each arc not on the spanning tree, add counting code as rtl. */ |
---|
910 | |
---|
911 | if (profile_arc_flag) |
---|
912 | instrument_arcs (f, num_blocks, dump_file); |
---|
913 | |
---|
914 | /* Execute the rest only if doing branch probabilities. */ |
---|
915 | if (! flag_branch_probabilities) |
---|
916 | return; |
---|
917 | |
---|
918 | /* For each arc not on the spanning tree, set its execution count from |
---|
919 | the .da file. */ |
---|
920 | |
---|
921 | /* The first count in the .da file is the number of times that the function |
---|
922 | was entered. This is the exec_count for block zero. */ |
---|
923 | |
---|
924 | num_arcs = 0; |
---|
925 | for (i = 0; i < num_blocks; i++) |
---|
926 | for (arcptr = bb_graph[i].succ; arcptr; arcptr = arcptr->succ_next) |
---|
927 | if (! arcptr->on_tree) |
---|
928 | { |
---|
929 | num_arcs++; |
---|
930 | if (da_file) |
---|
931 | { |
---|
932 | long value; |
---|
933 | __read_long (&value, da_file, 8); |
---|
934 | ARC_COUNT (arcptr) = value; |
---|
935 | } |
---|
936 | else |
---|
937 | ARC_COUNT (arcptr) = 0; |
---|
938 | arcptr->count_valid = 1; |
---|
939 | bb_graph[i].succ_count--; |
---|
940 | bb_graph[ARC_TARGET (arcptr)].pred_count--; |
---|
941 | } |
---|
942 | |
---|
943 | if (dump_file) |
---|
944 | fprintf (dump_file, "%d arc counts read\n", num_arcs); |
---|
945 | |
---|
946 | /* For every block in the file, |
---|
947 | - if every exit/entrance arc has a known count, then set the block count |
---|
948 | - if the block count is known, and every exit/entrance arc but one has |
---|
949 | a known execution count, then set the count of the remaining arc |
---|
950 | |
---|
951 | As arc counts are set, decrement the succ/pred count, but don't delete |
---|
952 | the arc, that way we can easily tell when all arcs are known, or only |
---|
953 | one arc is unknown. */ |
---|
954 | |
---|
955 | /* The order that the basic blocks are iterated through is important. |
---|
956 | Since the code that finds spanning trees starts with block 0, low numbered |
---|
957 | arcs are put on the spanning tree in preference to high numbered arcs. |
---|
958 | Hence, most instrumented arcs are at the end. Graph solving works much |
---|
959 | faster if we propagate numbers from the end to the start. |
---|
960 | |
---|
961 | This takes an average of slightly more than 3 passes. */ |
---|
962 | |
---|
963 | changes = 1; |
---|
964 | passes = 0; |
---|
965 | while (changes) |
---|
966 | { |
---|
967 | passes++; |
---|
968 | changes = 0; |
---|
969 | |
---|
970 | for (i = num_blocks - 1; i >= 0; i--) |
---|
971 | { |
---|
972 | struct bb_info *binfo = &bb_graph[i]; |
---|
973 | if (! binfo->count_valid) |
---|
974 | { |
---|
975 | if (binfo->succ_count == 0) |
---|
976 | { |
---|
977 | total = 0; |
---|
978 | for (arcptr = binfo->succ; arcptr; |
---|
979 | arcptr = arcptr->succ_next) |
---|
980 | total += ARC_COUNT (arcptr); |
---|
981 | binfo->exec_count = total; |
---|
982 | binfo->count_valid = 1; |
---|
983 | changes = 1; |
---|
984 | } |
---|
985 | else if (binfo->pred_count == 0) |
---|
986 | { |
---|
987 | total = 0; |
---|
988 | for (arcptr = binfo->pred; arcptr; |
---|
989 | arcptr = arcptr->pred_next) |
---|
990 | total += ARC_COUNT (arcptr); |
---|
991 | binfo->exec_count = total; |
---|
992 | binfo->count_valid = 1; |
---|
993 | changes = 1; |
---|
994 | } |
---|
995 | } |
---|
996 | if (binfo->count_valid) |
---|
997 | { |
---|
998 | if (binfo->succ_count == 1) |
---|
999 | { |
---|
1000 | total = 0; |
---|
1001 | /* One of the counts will be invalid, but it is zero, |
---|
1002 | so adding it in also doesn't hurt. */ |
---|
1003 | for (arcptr = binfo->succ; arcptr; |
---|
1004 | arcptr = arcptr->succ_next) |
---|
1005 | total += ARC_COUNT (arcptr); |
---|
1006 | /* Calculate count for remaining arc by conservation. */ |
---|
1007 | total = binfo->exec_count - total; |
---|
1008 | /* Search for the invalid arc, and set its count. */ |
---|
1009 | for (arcptr = binfo->succ; arcptr; |
---|
1010 | arcptr = arcptr->succ_next) |
---|
1011 | if (! arcptr->count_valid) |
---|
1012 | break; |
---|
1013 | if (! arcptr) |
---|
1014 | abort (); |
---|
1015 | arcptr->count_valid = 1; |
---|
1016 | ARC_COUNT (arcptr) = total; |
---|
1017 | binfo->succ_count--; |
---|
1018 | |
---|
1019 | bb_graph[ARC_TARGET (arcptr)].pred_count--; |
---|
1020 | changes = 1; |
---|
1021 | } |
---|
1022 | if (binfo->pred_count == 1) |
---|
1023 | { |
---|
1024 | total = 0; |
---|
1025 | /* One of the counts will be invalid, but it is zero, |
---|
1026 | so adding it in also doesn't hurt. */ |
---|
1027 | for (arcptr = binfo->pred; arcptr; |
---|
1028 | arcptr = arcptr->pred_next) |
---|
1029 | total += ARC_COUNT (arcptr); |
---|
1030 | /* Calculate count for remaining arc by conservation. */ |
---|
1031 | total = binfo->exec_count - total; |
---|
1032 | /* Search for the invalid arc, and set its count. */ |
---|
1033 | for (arcptr = binfo->pred; arcptr; |
---|
1034 | arcptr = arcptr->pred_next) |
---|
1035 | if (! arcptr->count_valid) |
---|
1036 | break; |
---|
1037 | if (! arcptr) |
---|
1038 | abort (); |
---|
1039 | arcptr->count_valid = 1; |
---|
1040 | ARC_COUNT (arcptr) = total; |
---|
1041 | binfo->pred_count--; |
---|
1042 | |
---|
1043 | bb_graph[ARC_SOURCE (arcptr)].succ_count--; |
---|
1044 | changes = 1; |
---|
1045 | } |
---|
1046 | } |
---|
1047 | } |
---|
1048 | } |
---|
1049 | |
---|
1050 | total_num_passes += passes; |
---|
1051 | if (dump_file) |
---|
1052 | fprintf (dump_file, "Graph solving took %d passes.\n\n", passes); |
---|
1053 | |
---|
1054 | /* If the graph has been correctly solved, every block will have a |
---|
1055 | succ and pred count of zero. */ |
---|
1056 | for (i = 0; i < num_blocks; i++) |
---|
1057 | { |
---|
1058 | struct bb_info *binfo = &bb_graph[i]; |
---|
1059 | if (binfo->succ_count || binfo->pred_count) |
---|
1060 | abort (); |
---|
1061 | } |
---|
1062 | |
---|
1063 | /* For every arc, calculate its branch probability and add a reg_note |
---|
1064 | to the branch insn to indicate this. */ |
---|
1065 | |
---|
1066 | for (i = 0; i < 20; i++) |
---|
1067 | hist_br_prob[i] = 0; |
---|
1068 | num_never_executed = 0; |
---|
1069 | num_branches = 0; |
---|
1070 | |
---|
1071 | for (i = 0; i < num_blocks; i++) |
---|
1072 | { |
---|
1073 | struct bb_info *binfo = &bb_graph[i]; |
---|
1074 | |
---|
1075 | total = binfo->exec_count; |
---|
1076 | for (arcptr = binfo->succ; arcptr; arcptr = arcptr->succ_next) |
---|
1077 | { |
---|
1078 | if (arcptr->branch_insn) |
---|
1079 | { |
---|
1080 | /* This calculates the branch probability as an integer between |
---|
1081 | 0 and REG_BR_PROB_BASE, properly rounded to the nearest |
---|
1082 | integer. Perform the arithmetic in double to avoid |
---|
1083 | overflowing the range of ints. */ |
---|
1084 | |
---|
1085 | if (total == 0) |
---|
1086 | prob = -1; |
---|
1087 | else |
---|
1088 | { |
---|
1089 | rtx pat = PATTERN (arcptr->branch_insn); |
---|
1090 | |
---|
1091 | prob = (((double)ARC_COUNT (arcptr) * REG_BR_PROB_BASE) |
---|
1092 | + (total >> 1)) / total; |
---|
1093 | if (prob < 0 || prob > REG_BR_PROB_BASE) |
---|
1094 | { |
---|
1095 | if (dump_file) |
---|
1096 | fprintf (dump_file, "bad count: prob for %d-%d thought to be %d (forcibly normalized)\n", |
---|
1097 | ARC_SOURCE (arcptr), ARC_TARGET (arcptr), |
---|
1098 | prob); |
---|
1099 | |
---|
1100 | bad_counts = 1; |
---|
1101 | prob = REG_BR_PROB_BASE / 2; |
---|
1102 | } |
---|
1103 | |
---|
1104 | /* Match up probability with JUMP pattern. */ |
---|
1105 | |
---|
1106 | if (GET_CODE (pat) == SET |
---|
1107 | && GET_CODE (SET_SRC (pat)) == IF_THEN_ELSE) |
---|
1108 | { |
---|
1109 | if (ARC_TARGET (arcptr) == ARC_SOURCE (arcptr) + 1) |
---|
1110 | { |
---|
1111 | /* A fall through arc should never have a |
---|
1112 | branch insn. */ |
---|
1113 | abort (); |
---|
1114 | } |
---|
1115 | else |
---|
1116 | { |
---|
1117 | /* This is the arc for the taken branch. */ |
---|
1118 | if (GET_CODE (XEXP (SET_SRC (pat), 2)) != PC) |
---|
1119 | prob = REG_BR_PROB_BASE - prob; |
---|
1120 | } |
---|
1121 | } |
---|
1122 | } |
---|
1123 | |
---|
1124 | if (prob == -1) |
---|
1125 | num_never_executed++; |
---|
1126 | else |
---|
1127 | { |
---|
1128 | int index = prob * 20 / REG_BR_PROB_BASE; |
---|
1129 | if (index == 20) |
---|
1130 | index = 19; |
---|
1131 | hist_br_prob[index]++; |
---|
1132 | } |
---|
1133 | num_branches++; |
---|
1134 | |
---|
1135 | REG_NOTES (arcptr->branch_insn) |
---|
1136 | = gen_rtx (EXPR_LIST, REG_BR_PROB, GEN_INT (prob), |
---|
1137 | REG_NOTES (arcptr->branch_insn)); |
---|
1138 | } |
---|
1139 | } |
---|
1140 | |
---|
1141 | /* Add a REG_EXEC_COUNT note to the first instruction of this block. */ |
---|
1142 | if (! binfo->first_insn |
---|
1143 | || GET_RTX_CLASS (GET_CODE (binfo->first_insn)) != 'i') |
---|
1144 | { |
---|
1145 | /* Block 0 is a fake block representing function entry, and does |
---|
1146 | not have a real first insn. The second last block might not |
---|
1147 | begin with a real insn. */ |
---|
1148 | if (i == num_blocks - 1) |
---|
1149 | return_label_execution_count = total; |
---|
1150 | else if (i != 0 && i != num_blocks - 2) |
---|
1151 | abort (); |
---|
1152 | } |
---|
1153 | else |
---|
1154 | { |
---|
1155 | REG_NOTES (binfo->first_insn) |
---|
1156 | = gen_rtx (EXPR_LIST, REG_EXEC_COUNT, GEN_INT (total), |
---|
1157 | REG_NOTES (binfo->first_insn)); |
---|
1158 | if (i == num_blocks - 1) |
---|
1159 | return_label_execution_count = total; |
---|
1160 | } |
---|
1161 | } |
---|
1162 | |
---|
1163 | /* This should never happen. */ |
---|
1164 | if (bad_counts) |
---|
1165 | warning ("Arc profiling: some arc counts were bad."); |
---|
1166 | |
---|
1167 | if (dump_file) |
---|
1168 | { |
---|
1169 | fprintf (dump_file, "%d branches\n", num_branches); |
---|
1170 | fprintf (dump_file, "%d branches never executed\n", |
---|
1171 | num_never_executed); |
---|
1172 | if (num_branches) |
---|
1173 | for (i = 0; i < 10; i++) |
---|
1174 | fprintf (dump_file, "%d%% branches in range %d-%d%%\n", |
---|
1175 | (hist_br_prob[i]+hist_br_prob[19-i])*100/num_branches, |
---|
1176 | 5*i, 5*i+5); |
---|
1177 | |
---|
1178 | total_num_branches += num_branches; |
---|
1179 | total_num_never_executed += num_never_executed; |
---|
1180 | for (i = 0; i < 20; i++) |
---|
1181 | total_hist_br_prob[i] += hist_br_prob[i]; |
---|
1182 | } |
---|
1183 | |
---|
1184 | } |
---|
1185 | |
---|
1186 | /* Initialize a new arc. |
---|
1187 | ARCPTR is the empty adj_list this function fills in. |
---|
1188 | SOURCE is the block number of the source block. |
---|
1189 | TARGET is the block number of the target block. |
---|
1190 | INSN is the insn which transfers control from SOURCE to TARGET, |
---|
1191 | or zero if the transfer is implicit. */ |
---|
1192 | |
---|
1193 | static void |
---|
1194 | init_arc (arcptr, source, target, insn) |
---|
1195 | struct adj_list *arcptr; |
---|
1196 | int source, target; |
---|
1197 | rtx insn; |
---|
1198 | { |
---|
1199 | ARC_TARGET (arcptr) = target; |
---|
1200 | ARC_SOURCE (arcptr) = source; |
---|
1201 | |
---|
1202 | ARC_COUNT (arcptr) = 0; |
---|
1203 | arcptr->count_valid = 0; |
---|
1204 | arcptr->on_tree = 0; |
---|
1205 | arcptr->fake = 0; |
---|
1206 | arcptr->fall_through = 0; |
---|
1207 | arcptr->branch_insn = insn; |
---|
1208 | |
---|
1209 | arcptr->succ_next = bb_graph[source].succ; |
---|
1210 | bb_graph[source].succ = arcptr; |
---|
1211 | bb_graph[source].succ_count++; |
---|
1212 | |
---|
1213 | arcptr->pred_next = bb_graph[target].pred; |
---|
1214 | bb_graph[target].pred = arcptr; |
---|
1215 | bb_graph[target].pred_count++; |
---|
1216 | } |
---|
1217 | |
---|
1218 | /* This function searches all of the arcs in the program flow graph, and puts |
---|
1219 | as many bad arcs as possible onto the spanning tree. Bad arcs include |
---|
1220 | fake arcs (needed for setjmp(), longjmp(), exit()) which MUST be on the |
---|
1221 | spanning tree as they can't be instrumented. Also, arcs which must be |
---|
1222 | split when instrumented should be part of the spanning tree if possible. */ |
---|
1223 | |
---|
1224 | static void |
---|
1225 | find_spanning_tree (num_blocks) |
---|
1226 | int num_blocks; |
---|
1227 | { |
---|
1228 | int i; |
---|
1229 | struct adj_list *arcptr; |
---|
1230 | struct bb_info *binfo = &bb_graph[0]; |
---|
1231 | |
---|
1232 | /* Fake arcs must be part of the spanning tree, and are always safe to put |
---|
1233 | on the spanning tree. Fake arcs will either be a successor of node 0, |
---|
1234 | a predecessor of the last node, or from the last node to node 0. */ |
---|
1235 | |
---|
1236 | for (arcptr = bb_graph[0].succ; arcptr; arcptr = arcptr->succ_next) |
---|
1237 | if (arcptr->fake) |
---|
1238 | { |
---|
1239 | /* Adding this arc should never cause a cycle. This is a fatal |
---|
1240 | error if it would. */ |
---|
1241 | if (bb_graph[ARC_TARGET (arcptr)].on_tree && binfo->on_tree) |
---|
1242 | abort(); |
---|
1243 | else |
---|
1244 | { |
---|
1245 | arcptr->on_tree = 1; |
---|
1246 | bb_graph[ARC_TARGET (arcptr)].on_tree = 1; |
---|
1247 | binfo->on_tree = 1; |
---|
1248 | } |
---|
1249 | } |
---|
1250 | |
---|
1251 | binfo = &bb_graph[num_blocks-1]; |
---|
1252 | for (arcptr = binfo->pred; arcptr; arcptr = arcptr->pred_next) |
---|
1253 | if (arcptr->fake) |
---|
1254 | { |
---|
1255 | /* Adding this arc should never cause a cycle. This is a fatal |
---|
1256 | error if it would. */ |
---|
1257 | if (bb_graph[ARC_SOURCE (arcptr)].on_tree && binfo->on_tree) |
---|
1258 | abort(); |
---|
1259 | else |
---|
1260 | { |
---|
1261 | arcptr->on_tree = 1; |
---|
1262 | bb_graph[ARC_SOURCE (arcptr)].on_tree = 1; |
---|
1263 | binfo->on_tree = 1; |
---|
1264 | } |
---|
1265 | } |
---|
1266 | /* The only entrace to node zero is a fake arc. */ |
---|
1267 | bb_graph[0].pred->on_tree = 1; |
---|
1268 | |
---|
1269 | /* Arcs which are crowded at both the source and target should be put on |
---|
1270 | the spanning tree if possible, except for fall_throuch arcs which never |
---|
1271 | require adding a new block even if crowded, add arcs with the same source |
---|
1272 | and dest which must always be instrumented. */ |
---|
1273 | for (i = 0; i < num_blocks; i++) |
---|
1274 | { |
---|
1275 | binfo = &bb_graph[i]; |
---|
1276 | |
---|
1277 | for (arcptr = binfo->succ; arcptr; arcptr = arcptr->succ_next) |
---|
1278 | if (! ((binfo->succ == arcptr && arcptr->succ_next == 0) |
---|
1279 | || (bb_graph[ARC_TARGET (arcptr)].pred |
---|
1280 | && arcptr->pred_next == 0)) |
---|
1281 | && ! arcptr->fall_through |
---|
1282 | && ARC_TARGET (arcptr) != i) |
---|
1283 | { |
---|
1284 | /* This is a crowded arc at both source and target. Try to put |
---|
1285 | in on the spanning tree. Can do this if either the source or |
---|
1286 | target block is not yet on the tree. */ |
---|
1287 | if (! bb_graph[ARC_TARGET (arcptr)].on_tree || ! binfo->on_tree) |
---|
1288 | { |
---|
1289 | arcptr->on_tree = 1; |
---|
1290 | bb_graph[ARC_TARGET (arcptr)].on_tree = 1; |
---|
1291 | binfo->on_tree = 1; |
---|
1292 | } |
---|
1293 | } |
---|
1294 | } |
---|
1295 | |
---|
1296 | /* Clear all of the basic block on_tree bits, so that we can use them to |
---|
1297 | create the spanning tree. */ |
---|
1298 | for (i = 0; i < num_blocks; i++) |
---|
1299 | bb_graph[i].on_tree = 0; |
---|
1300 | |
---|
1301 | /* Now fill in the spanning tree until every basic block is on it. |
---|
1302 | Don't put the 0 to 1 fall through arc on the tree, since it is |
---|
1303 | always cheap to instrument, so start filling the tree from node 1. */ |
---|
1304 | |
---|
1305 | for (i = 1; i < num_blocks; i++) |
---|
1306 | for (arcptr = bb_graph[i].succ; arcptr; arcptr = arcptr->succ_next) |
---|
1307 | if (! arcptr->on_tree |
---|
1308 | && ! bb_graph[ARC_TARGET (arcptr)].on_tree) |
---|
1309 | { |
---|
1310 | fill_spanning_tree (i); |
---|
1311 | break; |
---|
1312 | } |
---|
1313 | } |
---|
1314 | |
---|
1315 | /* Add arcs reached from BLOCK to the spanning tree if they are needed and |
---|
1316 | not already there. */ |
---|
1317 | |
---|
1318 | static void |
---|
1319 | fill_spanning_tree (block) |
---|
1320 | int block; |
---|
1321 | { |
---|
1322 | struct adj_list *arcptr; |
---|
1323 | |
---|
1324 | expand_spanning_tree (block); |
---|
1325 | |
---|
1326 | for (arcptr = bb_graph[block].succ; arcptr; arcptr = arcptr->succ_next) |
---|
1327 | if (! arcptr->on_tree |
---|
1328 | && ! bb_graph[ARC_TARGET (arcptr)].on_tree) |
---|
1329 | { |
---|
1330 | arcptr->on_tree = 1; |
---|
1331 | fill_spanning_tree (ARC_TARGET (arcptr)); |
---|
1332 | } |
---|
1333 | } |
---|
1334 | |
---|
1335 | /* When first visit a block, must add all blocks that are already connected |
---|
1336 | to this block via tree arcs to the spanning tree. */ |
---|
1337 | |
---|
1338 | static void |
---|
1339 | expand_spanning_tree (block) |
---|
1340 | int block; |
---|
1341 | { |
---|
1342 | struct adj_list *arcptr; |
---|
1343 | |
---|
1344 | bb_graph[block].on_tree = 1; |
---|
1345 | |
---|
1346 | for (arcptr = bb_graph[block].succ; arcptr; arcptr = arcptr->succ_next) |
---|
1347 | if (arcptr->on_tree && ! bb_graph[ARC_TARGET (arcptr)].on_tree) |
---|
1348 | expand_spanning_tree (ARC_TARGET (arcptr)); |
---|
1349 | |
---|
1350 | for (arcptr = bb_graph[block].pred; |
---|
1351 | arcptr; arcptr = arcptr->pred_next) |
---|
1352 | if (arcptr->on_tree && ! bb_graph[ARC_SOURCE (arcptr)].on_tree) |
---|
1353 | expand_spanning_tree (ARC_SOURCE (arcptr)); |
---|
1354 | } |
---|
1355 | |
---|
1356 | /* Perform file-level initialization for branch-prob processing. */ |
---|
1357 | |
---|
1358 | void |
---|
1359 | init_branch_prob (filename) |
---|
1360 | char *filename; |
---|
1361 | { |
---|
1362 | long len; |
---|
1363 | int i; |
---|
1364 | |
---|
1365 | if (flag_test_coverage) |
---|
1366 | { |
---|
1367 | /* Open an output file for the basic block/line number map. */ |
---|
1368 | int len = strlen (filename); |
---|
1369 | char *data_file = (char *) alloca (len + 4); |
---|
1370 | strcpy (data_file, filename); |
---|
1371 | strip_off_ending (data_file, len); |
---|
1372 | strcat (data_file, ".bb"); |
---|
1373 | if ((bb_file = fopen (data_file, "w")) == 0) |
---|
1374 | pfatal_with_name (data_file); |
---|
1375 | |
---|
1376 | /* Open an output file for the program flow graph. */ |
---|
1377 | len = strlen (filename); |
---|
1378 | bbg_file_name = (char *) alloca (len + 5); |
---|
1379 | strcpy (bbg_file_name, filename); |
---|
1380 | strip_off_ending (bbg_file_name, len); |
---|
1381 | strcat (bbg_file_name, ".bbg"); |
---|
1382 | if ((bbg_file = fopen (bbg_file_name, "w")) == 0) |
---|
1383 | pfatal_with_name (bbg_file_name); |
---|
1384 | |
---|
1385 | /* Initialize to zero, to ensure that the first file name will be |
---|
1386 | written to the .bb file. */ |
---|
1387 | last_bb_file_name = 0; |
---|
1388 | } |
---|
1389 | |
---|
1390 | if (flag_branch_probabilities) |
---|
1391 | { |
---|
1392 | len = strlen (filename); |
---|
1393 | da_file_name = (char *) alloca (len + 4); |
---|
1394 | strcpy (da_file_name, filename); |
---|
1395 | strip_off_ending (da_file_name, len); |
---|
1396 | strcat (da_file_name, ".da"); |
---|
1397 | if ((da_file = fopen (da_file_name, "r")) == 0) |
---|
1398 | warning ("file %s not found, execution counts assumed to be zero.", |
---|
1399 | da_file_name); |
---|
1400 | |
---|
1401 | /* The first word in the .da file gives the number of instrumented arcs, |
---|
1402 | which is not needed for our purposes. */ |
---|
1403 | |
---|
1404 | if (da_file) |
---|
1405 | __read_long (&len, da_file, 8); |
---|
1406 | } |
---|
1407 | |
---|
1408 | if (profile_arc_flag) |
---|
1409 | init_arc_profiler (); |
---|
1410 | |
---|
1411 | total_num_blocks = 0; |
---|
1412 | total_num_arcs = 0; |
---|
1413 | total_num_arcs_instrumented = 0; |
---|
1414 | total_num_blocks_created = 0; |
---|
1415 | total_num_passes = 0; |
---|
1416 | total_num_times_called = 0; |
---|
1417 | total_num_branches = 0; |
---|
1418 | total_num_never_executed = 0; |
---|
1419 | for (i = 0; i < 20; i++) |
---|
1420 | total_hist_br_prob[i] = 0; |
---|
1421 | } |
---|
1422 | |
---|
1423 | /* Performs file-level cleanup after branch-prob processing |
---|
1424 | is completed. */ |
---|
1425 | |
---|
1426 | void |
---|
1427 | end_branch_prob (dump_file) |
---|
1428 | FILE *dump_file; |
---|
1429 | { |
---|
1430 | if (flag_test_coverage) |
---|
1431 | { |
---|
1432 | fclose (bb_file); |
---|
1433 | fclose (bbg_file); |
---|
1434 | } |
---|
1435 | |
---|
1436 | if (flag_branch_probabilities) |
---|
1437 | { |
---|
1438 | if (da_file) |
---|
1439 | { |
---|
1440 | long temp; |
---|
1441 | /* This seems slightly dangerous, as it presumes the EOF |
---|
1442 | flag will not be set until an attempt is made to read |
---|
1443 | past the end of the file. */ |
---|
1444 | if (feof (da_file)) |
---|
1445 | warning (".da file contents exhausted too early\n"); |
---|
1446 | /* Should be at end of file now. */ |
---|
1447 | if (__read_long (&temp, da_file, 8) == 0) |
---|
1448 | warning (".da file contents not exhausted\n"); |
---|
1449 | fclose (da_file); |
---|
1450 | } |
---|
1451 | } |
---|
1452 | |
---|
1453 | if (dump_file) |
---|
1454 | { |
---|
1455 | fprintf (dump_file, "\n"); |
---|
1456 | fprintf (dump_file, "Total number of blocks: %d\n", total_num_blocks); |
---|
1457 | fprintf (dump_file, "Total number of arcs: %d\n", total_num_arcs); |
---|
1458 | fprintf (dump_file, "Total number of instrumented arcs: %d\n", |
---|
1459 | total_num_arcs_instrumented); |
---|
1460 | fprintf (dump_file, "Total number of blocks created: %d\n", |
---|
1461 | total_num_blocks_created); |
---|
1462 | fprintf (dump_file, "Total number of graph solution passes: %d\n", |
---|
1463 | total_num_passes); |
---|
1464 | if (total_num_times_called != 0) |
---|
1465 | fprintf (dump_file, "Average number of graph solution passes: %d\n", |
---|
1466 | (total_num_passes + (total_num_times_called >> 1)) |
---|
1467 | / total_num_times_called); |
---|
1468 | fprintf (dump_file, "Total number of branches: %d\n", total_num_branches); |
---|
1469 | fprintf (dump_file, "Total number of branches never executed: %d\n", |
---|
1470 | total_num_never_executed); |
---|
1471 | if (total_num_branches) |
---|
1472 | { |
---|
1473 | int i; |
---|
1474 | |
---|
1475 | for (i = 0; i < 10; i++) |
---|
1476 | fprintf (dump_file, "%d%% branches in range %d-%d%%\n", |
---|
1477 | (total_hist_br_prob[i] + total_hist_br_prob[19-i]) * 100 |
---|
1478 | / total_num_branches, 5*i, 5*i+5); |
---|
1479 | } |
---|
1480 | } |
---|
1481 | } |
---|
1482 | |
---|
1483 | /* The label used by the arc profiling code. */ |
---|
1484 | |
---|
1485 | static rtx profiler_label; |
---|
1486 | |
---|
1487 | /* Initialize the profiler_label. */ |
---|
1488 | |
---|
1489 | static void |
---|
1490 | init_arc_profiler () |
---|
1491 | { |
---|
1492 | /* Generate and save a copy of this so it can be shared. */ |
---|
1493 | char *name = xmalloc (20); |
---|
1494 | ASM_GENERATE_INTERNAL_LABEL (name, "LPBX", 2); |
---|
1495 | profiler_label = gen_rtx (SYMBOL_REF, Pmode, name); |
---|
1496 | } |
---|
1497 | |
---|
1498 | /* Output instructions as RTL to increment the arc execution count. */ |
---|
1499 | |
---|
1500 | static void |
---|
1501 | output_arc_profiler (arcno, insert_after) |
---|
1502 | int arcno; |
---|
1503 | rtx insert_after; |
---|
1504 | { |
---|
1505 | rtx profiler_target_addr |
---|
1506 | = (arcno |
---|
1507 | ? gen_rtx (CONST, Pmode, |
---|
1508 | gen_rtx (PLUS, Pmode, profiler_label, |
---|
1509 | gen_rtx (CONST_INT, VOIDmode, |
---|
1510 | LONG_TYPE_SIZE / BITS_PER_UNIT * arcno))) |
---|
1511 | : profiler_label); |
---|
1512 | enum machine_mode mode = mode_for_size (LONG_TYPE_SIZE, MODE_INT, 0); |
---|
1513 | rtx profiler_reg = gen_reg_rtx (mode); |
---|
1514 | rtx address_reg = gen_reg_rtx (Pmode); |
---|
1515 | rtx mem_ref, add_ref; |
---|
1516 | rtx sequence; |
---|
1517 | |
---|
1518 | /* In this case, reload can use explicitly mentioned hard registers for |
---|
1519 | reloads. It is not safe to output profiling code between a call |
---|
1520 | and the instruction that copies the result to a pseudo-reg. This |
---|
1521 | is because reload may allocate one of the profiling code pseudo-regs |
---|
1522 | to the return value reg, thus clobbering the return value. So we |
---|
1523 | must check for calls here, and emit the profiling code after the |
---|
1524 | instruction that uses the return value, if any. |
---|
1525 | |
---|
1526 | ??? The code here performs the same tests that reload does so hopefully |
---|
1527 | all the bases are covered. */ |
---|
1528 | |
---|
1529 | if (SMALL_REGISTER_CLASSES |
---|
1530 | && GET_CODE (insert_after) == CALL_INSN |
---|
1531 | && (GET_CODE (PATTERN (insert_after)) == SET |
---|
1532 | || (GET_CODE (PATTERN (insert_after)) == PARALLEL |
---|
1533 | && GET_CODE (XVECEXP (PATTERN (insert_after), 0, 0)) == SET))) |
---|
1534 | { |
---|
1535 | rtx return_reg; |
---|
1536 | rtx next_insert_after = next_nonnote_insn (insert_after); |
---|
1537 | |
---|
1538 | /* The first insn after the call may be a stack pop, skip it. */ |
---|
1539 | if (next_insert_after |
---|
1540 | && GET_CODE (next_insert_after) == INSN |
---|
1541 | && GET_CODE (PATTERN (next_insert_after)) == SET |
---|
1542 | && SET_DEST (PATTERN (next_insert_after)) == stack_pointer_rtx) |
---|
1543 | next_insert_after = next_nonnote_insn (next_insert_after); |
---|
1544 | |
---|
1545 | if (next_insert_after |
---|
1546 | && GET_CODE (next_insert_after) == INSN) |
---|
1547 | { |
---|
1548 | if (GET_CODE (PATTERN (insert_after)) == SET) |
---|
1549 | return_reg = SET_DEST (PATTERN (insert_after)); |
---|
1550 | else |
---|
1551 | return_reg = SET_DEST (XVECEXP (PATTERN (insert_after), 0, 0)); |
---|
1552 | |
---|
1553 | /* Now, NEXT_INSERT_AFTER may be an instruction that uses the |
---|
1554 | return value. However, it could also be something else, |
---|
1555 | like a CODE_LABEL, so check that the code is INSN. */ |
---|
1556 | if (next_insert_after != 0 |
---|
1557 | && GET_RTX_CLASS (GET_CODE (next_insert_after)) == 'i' |
---|
1558 | && reg_referenced_p (return_reg, PATTERN (next_insert_after))) |
---|
1559 | insert_after = next_insert_after; |
---|
1560 | } |
---|
1561 | } |
---|
1562 | |
---|
1563 | start_sequence (); |
---|
1564 | |
---|
1565 | emit_move_insn (address_reg, profiler_target_addr); |
---|
1566 | mem_ref = gen_rtx (MEM, mode, address_reg); |
---|
1567 | emit_move_insn (profiler_reg, mem_ref); |
---|
1568 | |
---|
1569 | add_ref = gen_rtx (PLUS, mode, profiler_reg, GEN_INT (1)); |
---|
1570 | emit_move_insn (profiler_reg, add_ref); |
---|
1571 | |
---|
1572 | /* This is the same rtx as above, but it is not legal to share this rtx. */ |
---|
1573 | mem_ref = gen_rtx (MEM, mode, address_reg); |
---|
1574 | emit_move_insn (mem_ref, profiler_reg); |
---|
1575 | |
---|
1576 | sequence = gen_sequence (); |
---|
1577 | end_sequence (); |
---|
1578 | emit_insn_after (sequence, insert_after); |
---|
1579 | } |
---|
1580 | |
---|
1581 | /* Output code for a constructor that will invoke __bb_init_func, if |
---|
1582 | this has not already been done. */ |
---|
1583 | |
---|
1584 | void |
---|
1585 | output_func_start_profiler () |
---|
1586 | { |
---|
1587 | tree fnname, fndecl; |
---|
1588 | char *name, *cfnname; |
---|
1589 | rtx table_address; |
---|
1590 | enum machine_mode mode = mode_for_size (LONG_TYPE_SIZE, MODE_INT, 0); |
---|
1591 | |
---|
1592 | /* It's either already been output, or we don't need it because we're |
---|
1593 | not doing profile-arcs. */ |
---|
1594 | if (! need_func_profiler) |
---|
1595 | return; |
---|
1596 | |
---|
1597 | need_func_profiler = 0; |
---|
1598 | |
---|
1599 | /* Synthesize a constructor function to invoke __bb_init_func with a |
---|
1600 | pointer to this object file's profile block. */ |
---|
1601 | start_sequence (); |
---|
1602 | |
---|
1603 | /* Try and make a unique name given the "file function name". |
---|
1604 | |
---|
1605 | And no, I don't like this either. */ |
---|
1606 | |
---|
1607 | fnname = get_file_function_name ('I'); |
---|
1608 | cfnname = IDENTIFIER_POINTER (fnname); |
---|
1609 | name = xmalloc (strlen (cfnname) + 5); |
---|
1610 | sprintf (name, "%sGCOV",cfnname); |
---|
1611 | fnname = get_identifier (name); |
---|
1612 | free (name); |
---|
1613 | |
---|
1614 | fndecl = build_decl (FUNCTION_DECL, fnname, |
---|
1615 | build_function_type (void_type_node, NULL_TREE)); |
---|
1616 | DECL_EXTERNAL (fndecl) = 0; |
---|
1617 | TREE_PUBLIC (fndecl) = 1; |
---|
1618 | DECL_ASSEMBLER_NAME (fndecl) = fnname; |
---|
1619 | DECL_RESULT (fndecl) = build_decl (RESULT_DECL, NULL_TREE, void_type_node); |
---|
1620 | current_function_decl = fndecl; |
---|
1621 | pushlevel (0); |
---|
1622 | make_function_rtl (fndecl); |
---|
1623 | init_function_start (fndecl, input_filename, lineno); |
---|
1624 | expand_function_start (fndecl, 0); |
---|
1625 | |
---|
1626 | /* Actually generate the code to call __bb_init_func. */ |
---|
1627 | name = xmalloc (20); |
---|
1628 | ASM_GENERATE_INTERNAL_LABEL (name, "LPBX", 0); |
---|
1629 | table_address = force_reg (Pmode, gen_rtx (SYMBOL_REF, Pmode, name)); |
---|
1630 | emit_library_call (gen_rtx (SYMBOL_REF, Pmode, "__bb_init_func"), 0, |
---|
1631 | mode, 1, table_address, Pmode); |
---|
1632 | |
---|
1633 | expand_function_end (input_filename, lineno, 0); |
---|
1634 | poplevel (1, 0, 1); |
---|
1635 | rest_of_compilation (fndecl); |
---|
1636 | if (! quiet_flag) |
---|
1637 | fflush (asm_out_file); |
---|
1638 | current_function_decl = NULL_TREE; |
---|
1639 | |
---|
1640 | assemble_constructor (IDENTIFIER_POINTER (DECL_NAME (fndecl))); |
---|
1641 | } |
---|