LCOV - code coverage report
Current view: top level - gcc/rtl-ssa - change-utils.h (source / functions) Hit Total Coverage
Test: gcc.info Lines: 12 12 100.0 %
Date: 2021-11-27 14:51:55 Functions: 3 3 100.0 %
Legend: Lines: hit not hit | Branches: + taken - not taken # not executed Branches: 0 0 -

           Branch data     Line data    Source code
       1                 :            : // RTL SSA utility functions for changing instructions              -*- C++ -*-
       2                 :            : // Copyright (C) 2020-2021 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                 :            : namespace rtl_ssa {
      21                 :            : 
      22                 :            : // Return true if INSN is one of the instructions being changed by CHANGES.
      23                 :            : inline bool
      24                 :            : insn_is_changing (array_slice<insn_change *const> changes,
      25                 :            :                   const insn_info *insn)
      26                 :            : {
      27                 :            :   for (const insn_change *change : changes)
      28                 :            :     if (change->insn () == insn)
      29                 :            :       return true;
      30                 :            :   return false;
      31                 :            : }
      32                 :            : 
      33                 :            : // Return a closure of insn_is_changing, for use as a predicate.
      34                 :            : // This could be done using local lambdas instead, but the predicate is
      35                 :            : // used often enough that having a class should be more convenient and allow
      36                 :            : // reuse of template instantiations.
      37                 :            : //
      38                 :            : // We don't use std::bind because it would involve an indirect function call,
      39                 :            : // whereas this function is used in relatively performance-critical code.
      40                 :            : inline insn_is_changing_closure
      41                 :            : insn_is_changing (array_slice<insn_change *const> changes)
      42                 :            : {
      43                 :            :   return insn_is_changing_closure (changes);
      44                 :            : }
      45                 :            : 
      46                 :            : // Restrict CHANGE.move_range so that the changed instruction can perform
      47                 :            : // all its definitions and uses.  Assume that if:
      48                 :            : //
      49                 :            : // - CHANGE contains an access A1 of resource R;
      50                 :            : // - an instruction I2 contains another access A2 to R; and
      51                 :            : // - IGNORE (I2) is true
      52                 :            : //
      53                 :            : // then either:
      54                 :            : //
      55                 :            : // - A2 will be removed; or
      56                 :            : // - something will ensure that A1 and A2 maintain their current order,
      57                 :            : //   without this having to be enforced by CHANGE's move range.
      58                 :            : //
      59                 :            : // IGNORE should return true for CHANGE.insn ().
      60                 :            : //
      61                 :            : // Return true on success, otherwise leave CHANGE.move_range in an invalid
      62                 :            : // state.
      63                 :            : //
      64                 :            : // This function only works correctly for instructions that remain within
      65                 :            : // the same extended basic block.
      66                 :            : template<typename IgnorePredicate>
      67                 :            : bool
      68                 :   23078386 : restrict_movement_ignoring (insn_change &change, IgnorePredicate ignore)
      69                 :            : {
      70                 :            :   // Uses generally lead to failure quicker, so test those first.
      71                 :   23078386 :   return (restrict_movement_for_uses_ignoring (change.move_range,
      72                 :            :                                                change.new_uses, ignore)
      73                 :   21982044 :           && restrict_movement_for_defs_ignoring (change.move_range,
      74                 :            :                                                   change.new_defs, ignore)
      75                 :   45060430 :           && canonicalize_move_range (change.move_range, change.insn ()));
      76                 :            : }
      77                 :            : 
      78                 :            : // Like restrict_movement_ignoring, but ignore only the instruction
      79                 :            : // that is being changed.
      80                 :            : inline bool
      81                 :   23078386 : restrict_movement (insn_change &change)
      82                 :            : {
      83                 :   23078386 :   return restrict_movement_ignoring (change, insn_is (change.insn ()));
      84                 :            : }
      85                 :            : 
      86                 :            : using add_regno_clobber_fn = std::function<bool (insn_change &,
      87                 :            :                                                  unsigned int)>;
      88                 :            : bool recog_internal (insn_change &, add_regno_clobber_fn);
      89                 :            : 
      90                 :            : // Try to recognize the new instruction pattern for CHANGE, potentially
      91                 :            : // tweaking the pattern or adding extra clobbers in order to make it match.
      92                 :            : //
      93                 :            : // When adding an extra clobber for register R, restrict CHANGE.move_range
      94                 :            : // to a range of instructions for which R is not live.  When determining
      95                 :            : // whether R is live, ignore accesses made by an instruction I if
      96                 :            : // IGNORE (I) is true.  The caller then assumes the responsibility
      97                 :            : // of ensuring that CHANGE and I are placed in a valid order.
      98                 :            : //
      99                 :            : // IGNORE should return true for CHANGE.insn ().
     100                 :            : //
     101                 :            : // Return true on success.  Leave CHANGE unmodified on failure.
     102                 :            : template<typename IgnorePredicate>
     103                 :            : inline bool
     104                 :    3742221 : recog_ignoring (obstack_watermark &watermark, insn_change &change,
     105                 :            :                 IgnorePredicate ignore)
     106                 :            : {
     107                 :    3742221 :   auto add_regno_clobber = [&](insn_change &change, unsigned int regno)
     108                 :            :     {
     109                 :        258 :       return crtl->ssa->add_regno_clobber (watermark, change, regno, ignore);
     110                 :            :     };
     111                 :    3742221 :   return recog_internal (change, add_regno_clobber);
     112                 :            : }
     113                 :            : 
     114                 :            : // As for recog_ignoring, but ignore only the instruction that is being
     115                 :            : // changed.
     116                 :            : inline bool
     117                 :    3742221 : recog (obstack_watermark &watermark, insn_change &change)
     118                 :            : {
     119                 :    3742221 :   return recog_ignoring (watermark, change, insn_is (change.insn ()));
     120                 :            : }
     121                 :            : 
     122                 :            : // Check whether insn costs indicate that the net effect of the changes
     123                 :            : // in CHANGES is worthwhile.  Require a strict improvement if STRICT_P,
     124                 :            : // otherwise allow the new instructions to be the same cost as the old
     125                 :            : // instructions.
     126                 :            : bool changes_are_worthwhile (array_slice<insn_change *const> changes,
     127                 :            :                              bool strict_p = false);
     128                 :            : 
     129                 :            : // Like changes_are_worthwhile, but for a single change.
     130                 :            : inline bool
     131                 :            : change_is_worthwhile (insn_change &change, bool strict_p = false)
     132                 :            : {
     133                 :            :   insn_change *changes[] = { &change };
     134                 :            :   return changes_are_worthwhile (changes, strict_p);
     135                 :            : }
     136                 :            : 
     137                 :            : }

Generated by: LCOV version 1.15+git.20200812.d100e6c

LCOV profile is generated on x86_64 machine using following configure options: configure --disable-bootstrap --enable-coverage=opt --enable-languages=c,c++,fortran,go,jit,lto --enable-host-shared. GCC test suite is run with the built compiler.