gcc/gimple-range-trace.cc

   1 /* Code for GIMPLE range trace and debugging related routines.
   2    Copyright (C) 2019-2024 Free Software Foundation, Inc.
   3    Contributed by Andrew MacLeod <amacleod@redhat.com>
   4    and Aldy Hernandez <aldyh@redhat.com>.
   5
   6 This file is part of GCC.
   7
   8 GCC is free software; you can redistribute it and/or modify
   9 it under the terms of the GNU General Public License as published by
  10 the Free Software Foundation; either version 3, or (at your option)
  11 any later version.
  12
  13 GCC is distributed in the hope that it will be useful,
  14 but WITHOUT ANY WARRANTY; without even the implied warranty of
  15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16 GNU General Public License for more details.
  17
  18 You should have received a copy of the GNU General Public License
  19 along with GCC; see the file COPYING3.  If not see
  20 <http://www.gnu.org/licenses/>.  */
  21
  22 #include "config.h"
  23 #include "system.h"
  24 #include "coretypes.h"
  25 #include "backend.h"
  26 #include "tree.h"
  27 #include "gimple.h"
  28 #include "ssa.h"
  29 #include "gimple-pretty-print.h"
  30 #include "gimple-iterator.h"
  31 #include "tree-cfg.h"
  32 #include "fold-const.h"
  33 #include "tree-cfg.h"
  34 #include "cfgloop.h"
  35 #include "tree-scalar-evolution.h"
  36 #include "gimple-range.h"
  37
  38
  39 // Breakpoint to trap at a specific index.  From GDB, this provides a simple
  40 // place to put a breakpoint to stop at a given trace line.
  41 // ie.  b range_tracer::breakpoint if index == 45678
  42
  43 void
  44 range_tracer::breakpoint (unsigned index ATTRIBUTE_UNUSED)
  45 {
  46 }
  47
  48 // Construct a range_tracer with component NAME.
  49
  50 range_tracer::range_tracer (const char *name)
  51 {
  52   gcc_checking_assert (strlen(name) < name_len -1);
  53   strcpy (component, name);
  54   indent = 0;
  55   tracing = false;
  56 }
  57
  58 // This routine does the initial line spacing/indenting for a trace.
  59 // If BLANKS is false, then IDX is printed, otherwise spaces.
  60
  61 void
  62 range_tracer::print_prefix (unsigned idx, bool blanks)
  63 {
  64   // Print counter index as well as INDENT spaces.
  65   if (!blanks)
  66     fprintf (dump_file, "%-7u ", idx);
  67   else
  68     fprintf (dump_file, "        ");
  69   fprintf (dump_file, "%s ", component);
  70   unsigned x;
  71   for (x = 0; x< indent; x++)
  72     fputc (' ', dump_file);
  73
  74 }
  75 // If dumping, return the next call index and print the prefix for the next
  76 // output line.  If not, return 0.
  77 // Counter is static to monotonically increase across the compilation unit.
  78
  79 unsigned
  80 range_tracer::do_header (const char *str)
  81 {
  82   static unsigned trace_count = 0;
  83
  84   unsigned idx = ++trace_count;
  85   print_prefix (idx, false);
  86   fprintf (dump_file, "%s", str);
  87   indent += bump;
  88   breakpoint (idx);
  89   return idx;
  90 }
  91
  92 // Print a line without starting or ending a trace.
  93
  94 void
  95 range_tracer::print (unsigned counter, const char *str)
  96 {
  97   print_prefix (counter, true);
  98   fprintf (dump_file, "%s", str);
  99 }
 100
 101 // End a trace and print the CALLER, NAME, and RESULT and range R,
 102
 103 void
 104 range_tracer::trailer (unsigned counter, const char *caller, bool result,
 105                       tree name, const vrange &r)
 106 {
 107   gcc_checking_assert (tracing && counter != 0);
 108
 109   indent -= bump;
 110   print_prefix (counter, true);
 111   fputs(result ? "TRUE : " : "FALSE : ", dump_file);
 112   fprintf (dump_file, "(%u) ", counter);
 113   fputs (caller, dump_file);
 114   fputs (" (",dump_file);
 115   if (name)
 116     print_generic_expr (dump_file, name, TDF_SLIM);
 117   fputs (") ",dump_file);
 118   if (result)
 119     {
 120       r.dump (dump_file);
 121       fputc('\n', dump_file);
 122     }
 123   else
 124     fputc('\n', dump_file);
 125 }
 126
 127 // =========================================
 128 // Debugging helpers.
 129 // =========================================
 130
 131 // Query all statements in the IL to precalculate computable ranges in RANGER.
 132
 133 DEBUG_FUNCTION void
 134 debug_seed_ranger (gimple_ranger &ranger)
 135 {
 136   // Recalculate SCEV to make sure the dump lists everything.
 137   if (scev_initialized_p ())
 138     {
 139       scev_finalize ();
 140       scev_initialize ();
 141     }
 142
 143   basic_block bb;
 144   gimple_stmt_iterator gsi;
 145   FOR_EACH_BB_FN (bb, cfun)
 146     for (gsi = gsi_start_bb (bb); !gsi_end_p (gsi); gsi_next (&gsi))
 147       {
 148         gimple *stmt = gsi_stmt (gsi);
 149
 150         if (is_gimple_debug (stmt))
 151           continue;
 152
 153         if (tree type = gimple_range_type (stmt))
 154           {
 155             Value_Range r (type);
 156             ranger.range_of_stmt (r, stmt);
 157           }
 158       }
 159 }
 160
 161 // Change the current dump_file and dump_flags to F and FLAGS while
 162 // saving them for later restoring.
 163
 164 push_dump_file::push_dump_file (FILE *f, dump_flags_t flags)
 165 {
 166   old_dump_file = dump_file;
 167   old_dump_flags = dump_flags;
 168   dump_file = f;
 169   dump_flags = flags;
 170 }
 171
 172 // Restore saved dump_file and dump_flags.
 173
 174 push_dump_file::~push_dump_file ()
 175 {
 176   dump_file = old_dump_file;
 177   dump_flags = old_dump_flags;
 178 }
 179
 180 // Dump all that ranger knows for the current function.
 181
 182 void
 183 dump_ranger (FILE *out)
 184 {
 185   push_dump_file save (out, dump_flags);
 186   gimple_ranger ranger;
 187
 188   fprintf (out, ";; Function ");
 189   print_generic_expr (out, current_function_decl);
 190   fprintf (out, "\n");
 191
 192   debug_seed_ranger (ranger);
 193   ranger.dump (out);
 194 }
 195
 196 DEBUG_FUNCTION void
 197 debug_ranger ()
 198 {
 199   dump_ranger (stderr);
 200 }
 201
 202 // Dump all that ranger knows on a path of BBs.
 203 //
 204 // Note that the blocks are in reverse order, thus the exit block is
 205 // path[0].
 206
 207 void
 208 dump_ranger (FILE *dump_file, const vec<basic_block> &path)
 209 {
 210   if (path.length () == 0)
 211     {
 212       fprintf (dump_file, "empty\n");
 213       return;
 214     }
 215
 216   gimple_ranger ranger;
 217   debug_seed_ranger (ranger);
 218
 219   unsigned i = path.length ();
 220   do
 221     {
 222       i--;
 223       ranger.dump_bb (dump_file, path[i]);
 224     }
 225   while (i > 0);
 226 }
 227
 228 DEBUG_FUNCTION void
 229 debug_ranger (const vec<basic_block> &path)
 230 {
 231   dump_ranger (stderr, path);
 232 }
 233
 234 #include "gimple-range-tests.cc"