LCOV - code coverage report
Current view: top level - gcc - stack-ptr-mod.c (source / functions) Hit Total Coverage
Test: gcc.info Lines: 23 23 100.0 %
Date: 2020-03-28 11:57:23 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                 :            : /* Discover if the stack pointer is modified in a function.
       2                 :            :    Copyright (C) 2007-2020 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 "backend.h"
      24                 :            : #include "rtl.h"
      25                 :            : #include "df.h"
      26                 :            : #include "memmodel.h"
      27                 :            : #include "emit-rtl.h"
      28                 :            : #include "tree-pass.h"
      29                 :            : 
      30                 :            : /* Determine if the stack pointer is constant over the life of the function.
      31                 :            :    Only useful before prologues have been emitted.  */
      32                 :            : 
      33                 :            : static void
      34                 :   38505100 : notice_stack_pointer_modification_1 (rtx x, const_rtx pat ATTRIBUTE_UNUSED,
      35                 :            :                                      void *data ATTRIBUTE_UNUSED)
      36                 :            : {
      37                 :   38505100 :   if (x == stack_pointer_rtx
      38                 :            :       /* The stack pointer is only modified indirectly as the result
      39                 :            :          of a push until later.  See the comments in rtl.texi
      40                 :            :          regarding Embedded Side-Effects on Addresses.  */
      41                 :   38400400 :       || (MEM_P (x)
      42                 :    5202760 :           && GET_RTX_CLASS (GET_CODE (XEXP (x, 0))) == RTX_AUTOINC
      43                 :      26213 :           && XEXP (XEXP (x, 0), 0) == stack_pointer_rtx))
      44                 :     130903 :     crtl->sp_is_unchanging = 0;
      45                 :   38505100 : }
      46                 :            : 
      47                 :            :   /* Some targets can emit simpler epilogues if they know that sp was
      48                 :            :      not ever modified during the function.  After reload, of course,
      49                 :            :      we've already emitted the epilogue so there's no sense searching.  */
      50                 :            : 
      51                 :            : namespace {
      52                 :            : 
      53                 :            : const pass_data pass_data_stack_ptr_mod =
      54                 :            : {
      55                 :            :   RTL_PASS, /* type */
      56                 :            :   "*stack_ptr_mod", /* name */
      57                 :            :   OPTGROUP_NONE, /* optinfo_flags */
      58                 :            :   TV_NONE, /* tv_id */
      59                 :            :   0, /* properties_required */
      60                 :            :   0, /* properties_provided */
      61                 :            :   0, /* properties_destroyed */
      62                 :            :   0, /* todo_flags_start */
      63                 :            :   0, /* todo_flags_finish */
      64                 :            : };
      65                 :            : 
      66                 :            : class pass_stack_ptr_mod : public rtl_opt_pass
      67                 :            : {
      68                 :            : public:
      69                 :     200540 :   pass_stack_ptr_mod (gcc::context *ctxt)
      70                 :     401080 :     : rtl_opt_pass (pass_data_stack_ptr_mod, ctxt)
      71                 :            :   {}
      72                 :            : 
      73                 :            :   /* opt_pass methods: */
      74                 :            :   virtual unsigned int execute (function *);
      75                 :            : 
      76                 :            : }; // class pass_stack_ptr_mod
      77                 :            : 
      78                 :            : unsigned int
      79                 :     942958 : pass_stack_ptr_mod::execute (function *fun)
      80                 :            : {
      81                 :     942958 :   basic_block bb;
      82                 :     942958 :   rtx_insn *insn;
      83                 :            : 
      84                 :            :   /* Assume that the stack pointer is unchanging if alloca hasn't
      85                 :            :      been used.  */
      86                 :     942958 :   crtl->sp_is_unchanging = !fun->calls_alloca;
      87                 :     942958 :   if (crtl->sp_is_unchanging)
      88                 :    7787960 :     FOR_EACH_BB_FN (bb, fun)
      89                 :  151397000 :       FOR_BB_INSNS (bb, insn)
      90                 :            :         {
      91                 :   72336500 :           if (INSN_P (insn))
      92                 :            :             {
      93                 :            :               /* Check if insn modifies the stack pointer.  */
      94                 :   59543600 :               note_stores (insn, notice_stack_pointer_modification_1, NULL);
      95                 :   59543600 :               if (! crtl->sp_is_unchanging)
      96                 :            :                 return 0;
      97                 :            :             }
      98                 :            :         }
      99                 :            : 
     100                 :            :   /* The value coming into this pass was 0, and the exit block uses
     101                 :            :      are based on this.  If the value is now 1, we need to redo the
     102                 :            :      exit block uses.  */
     103                 :     812055 :   if (df && crtl->sp_is_unchanging)
     104                 :     802381 :     df_update_exit_block_uses ();
     105                 :            : 
     106                 :            :   return 0;
     107                 :            : }
     108                 :            : 
     109                 :            : } // anon namespace
     110                 :            : 
     111                 :            : rtl_opt_pass *
     112                 :     200540 : make_pass_stack_ptr_mod (gcc::context *ctxt)
     113                 :            : {
     114                 :     200540 :   return new pass_stack_ptr_mod (ctxt);
     115                 :            : }

Generated by: LCOV version 1.0

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.