gcc/print-rtl-function.cc

   1 /* Print RTL functions for GCC.
   2    Copyright (C) 2016-2024 Free Software Foundation, Inc.
   3
   4 This file is part of GCC.
   5
   6 GCC is free software; you can redistribute it and/or modify it under
   7 the terms of the GNU General Public License as published by the Free
   8 Software Foundation; either version 3, or (at your option) any later
   9 version.
  10
  11 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
  12 WARRANTY; without even the implied warranty of MERCHANTABILITY or
  13 FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  14 for more details.
  15
  16 You should have received a copy of the GNU General Public License
  17 along with GCC; see the file COPYING3.  If not see
  18 <http://www.gnu.org/licenses/>.  */
  19
  20 #include "config.h"
  21 #include "system.h"
  22 #include "coretypes.h"
  23 #include "tm.h"
  24 #include "rtl.h"
  25 #include "alias.h"
  26 #include "tree.h"
  27 #include "flags.h"
  28 #include "predict.h"
  29 #include "function.h"
  30 #include "basic-block.h"
  31 #include "print-rtl.h"
  32 #include "langhooks.h"
  33 #include "memmodel.h"
  34 #include "emit-rtl.h"
  35 #include "varasm.h"
  36
  37 /* Print an "(edge-from)" or "(edge-to)" directive describing E
  38    to OUTFILE.  */
  39
  40 static void
  41 print_edge (FILE *outfile, edge e, bool from)
  42 {
  43   fprintf (outfile, "      (%s ", from ? "edge-from" : "edge-to");
  44   basic_block bb = from ? e->src : e->dest;
  45   gcc_assert (bb);
  46   switch (bb->index)
  47     {
  48     case ENTRY_BLOCK:
  49       fprintf (outfile, "entry");
  50       break;
  51     case EXIT_BLOCK:
  52       fprintf (outfile, "exit");
  53       break;
  54     default:
  55       fprintf (outfile, "%i", bb->index);
  56       break;
  57     }
  58
  59   /* Express edge flags as a string with " | " separator.
  60      e.g. (flags "FALLTHRU | DFS_BACK").  */
  61   if (e->flags)
  62     {
  63       fprintf (outfile, " (flags \"");
  64       bool seen_flag = false;
  65 #define DEF_EDGE_FLAG(NAME,IDX)                 \
  66   do {                                          \
  67     if (e->flags & EDGE_##NAME)                 \
  68       {                                         \
  69         if (seen_flag)                          \
  70           fprintf (outfile, " | ");             \
  71         fprintf (outfile, "%s", (#NAME));       \
  72         seen_flag = true;                       \
  73       }                                         \
  74   } while (0);
  75 #include "cfg-flags.def"
  76 #undef DEF_EDGE_FLAG
  77
  78       fprintf (outfile, "\")");
  79     }
  80
  81   fprintf (outfile, ")\n");
  82 }
  83
  84 /* If BB is non-NULL, print the start of a "(block)" directive for it
  85    to OUTFILE, otherwise do nothing.  */
  86
  87 static void
  88 begin_any_block (FILE *outfile, basic_block bb)
  89 {
  90   if (!bb)
  91     return;
  92
  93   edge e;
  94   edge_iterator ei;
  95
  96   fprintf (outfile, "    (block %i\n", bb->index);
  97   FOR_EACH_EDGE (e, ei, bb->preds)
  98     print_edge (outfile, e, true);
  99 }
 100
 101 /* If BB is non-NULL, print the end of a "(block)" directive for it
 102    to OUTFILE, otherwise do nothing.  */
 103
 104 static void
 105 end_any_block (FILE *outfile, basic_block bb)
 106 {
 107   if (!bb)
 108     return;
 109
 110   edge e;
 111   edge_iterator ei;
 112
 113   FOR_EACH_EDGE (e, ei, bb->succs)
 114     print_edge (outfile, e, false);
 115   fprintf (outfile, "    ) ;; block %i\n", bb->index);
 116 }
 117
 118 /* Determine if INSN is of a kind that can have a basic block.  */
 119
 120 static bool
 121 can_have_basic_block_p (const rtx_insn *insn)
 122 {
 123   rtx_code code = GET_CODE (insn);
 124   if (code == BARRIER)
 125     return false;
 126   gcc_assert (GET_RTX_FORMAT (code)[2] == 'B');
 127   return true;
 128 }
 129
 130 /* Subroutine of print_param.  Write the name of ARG, if any, to OUTFILE.  */
 131
 132 static void
 133 print_any_param_name (FILE *outfile, tree arg)
 134 {
 135   if (DECL_NAME (arg))
 136     fprintf (outfile, " \"%s\"", IDENTIFIER_POINTER (DECL_NAME (arg)));
 137 }
 138
 139 /* Print a "(param)" directive for ARG to OUTFILE.  */
 140
 141 static void
 142 print_param (FILE *outfile, rtx_writer &w, tree arg)
 143 {
 144   fprintf (outfile, "  (param");
 145   print_any_param_name (outfile, arg);
 146   fprintf (outfile, "\n");
 147
 148   /* Print the value of DECL_RTL (without lazy-evaluation).  */
 149   fprintf (outfile, "    (DECL_RTL ");
 150   w.print_rtx (DECL_RTL_IF_SET (arg));
 151   w.finish_directive ();
 152
 153   /* Print DECL_INCOMING_RTL.  */
 154   fprintf (outfile, "    (DECL_RTL_INCOMING ");
 155   w.print_rtx (DECL_INCOMING_RTL (arg));
 156   fprintf (outfile, ")");
 157
 158   w.finish_directive ();
 159 }
 160
 161 /* Write FN to OUTFILE in a form suitable for parsing, with indentation
 162    and comments to make the structure easy for a human to grok.  Track
 163    the basic blocks of insns in the chain, wrapping those that are within
 164    blocks within "(block)" directives.
 165
 166    If COMPACT, then instructions are printed in a compact form:
 167    - INSN_UIDs are omitted, except for jumps and CODE_LABELs,
 168    - INSN_CODEs are omitted,
 169    - register numbers are omitted for hard and virtual regs, and
 170      non-virtual pseudos are offset relative to the first such reg, and
 171      printed with a '%' sigil e.g. "%0" for (LAST_VIRTUAL_REGISTER + 1),
 172    - insn names are prefixed with "c" (e.g. "cinsn", "cnote", etc)
 173
 174    Example output (with COMPACT==true):
 175
 176    (function "times_two"
 177      (param "i"
 178        (DECL_RTL (mem/c:SI (plus:DI (reg/f:DI virtual-stack-vars)
 179            (const_int -4)) [1 i+0 S4 A32]))
 180        (DECL_RTL_INCOMING (reg:SI di [ i ])))
 181      (insn-chain
 182        (cnote 1 NOTE_INSN_DELETED)
 183        (block 2
 184          (edge-from entry (flags "FALLTHRU"))
 185          (cnote 4 [bb 2] NOTE_INSN_BASIC_BLOCK)
 186          (cinsn 2 (set (mem/c:SI (plus:DI (reg/f:DI virtual-stack-vars)
 187                                (const_int -4)) [1 i+0 S4 A32])
 188                        (reg:SI di [ i ])) "t.c":2)
 189          (cnote 3 NOTE_INSN_FUNCTION_BEG)
 190          (cinsn 6 (set (reg:SI <2>)
 191                        (mem/c:SI (plus:DI (reg/f:DI virtual-stack-vars)
 192                                (const_int -4)) [1 i+0 S4 A32])) "t.c":3)
 193          (cinsn 7 (parallel [
 194                            (set (reg:SI <0> [ _2 ])
 195                                (ashift:SI (reg:SI <2>)
 196                                    (const_int 1)))
 197                            (clobber (reg:CC flags))
 198                        ]) "t.c":3
 199                     (expr_list:REG_EQUAL (ashift:SI (mem/c:SI (plus:DI (reg/f:DI virtual-stack-vars)
 200                                    (const_int -4)) [1 i+0 S4 A32])
 201                            (const_int 1))))
 202          (cinsn 10 (set (reg:SI <1> [ <retval> ])
 203                        (reg:SI <0> [ _2 ])) "t.c":3)
 204          (cinsn 14 (set (reg/i:SI ax)
 205                        (reg:SI <1> [ <retval> ])) "t.c":4)
 206          (cinsn 15 (use (reg/i:SI ax)) "t.c":4)
 207          (edge-to exit (flags "FALLTHRU"))
 208        ) ;; block 2
 209      ) ;; insn-chain
 210      (crtl
 211        (return_rtx
 212          (reg/i:SI ax)
 213        ) ;; return_rtx
 214      ) ;; crtl
 215    ) ;; function "times_two"
 216 */
 217
 218 DEBUG_FUNCTION void
 219 print_rtx_function (FILE *outfile, function *fn, bool compact)
 220 {
 221   rtx_reuse_manager r;
 222   rtx_writer w (outfile, 0, false, compact, &r);
 223
 224   /* Support "reuse_rtx" in the dump.  */
 225   for (rtx_insn *insn = get_insns (); insn; insn = NEXT_INSN (insn))
 226     r.preprocess (insn);
 227
 228   tree fdecl = fn->decl;
 229
 230   const char *dname = lang_hooks.decl_printable_name (fdecl, 1);
 231
 232   fprintf (outfile, "(function \"%s\"\n", dname);
 233
 234   /* Params.  */
 235   for (tree arg = DECL_ARGUMENTS (fdecl); arg; arg = DECL_CHAIN (arg))
 236     print_param (outfile, w, arg);
 237
 238   /* The instruction chain.  */
 239   fprintf (outfile, "  (insn-chain\n");
 240   basic_block curr_bb = NULL;
 241   for (rtx_insn *insn = get_insns (); insn; insn = NEXT_INSN (insn))
 242     {
 243       basic_block insn_bb;
 244       if (can_have_basic_block_p (insn))
 245         insn_bb = BLOCK_FOR_INSN (insn);
 246       else
 247         insn_bb = NULL;
 248       if (curr_bb != insn_bb)
 249         {
 250           end_any_block (outfile, curr_bb);
 251           curr_bb = insn_bb;
 252           begin_any_block (outfile, curr_bb);
 253         }
 254       w.print_rtl_single_with_indent (insn, curr_bb ? 6 : 4);
 255     }
 256   end_any_block (outfile, curr_bb);
 257   fprintf (outfile, "  ) ;; insn-chain\n");
 258
 259   /* Additional RTL state.  */
 260   fprintf (outfile, "  (crtl\n");
 261   fprintf (outfile, "    (return_rtx \n");
 262   w.print_rtl_single_with_indent (crtl->return_rtx, 6);
 263   fprintf (outfile, "    ) ;; return_rtx\n");
 264   fprintf (outfile, "  ) ;; crtl\n");
 265
 266   fprintf (outfile, ") ;; function \"%s\"\n", dname);
 267 }