[Bug optimization/12039] [tree-ssa] [unit-at-a-time] does not mark static variable as used.

["judd dot jenne at charter dot net" <gcc-bugzilla at gcc dot gnu dot org>]

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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=12039



------- Additional Comments From judd dot jenne at charter dot net  2003-08-31 03:33 -------
[Brought in from gcc mailing list.]

Andrew,

First of all, thank you for looking into this.

I produced these using an ssa compiler from the last few hours. I hope this helps.

I used something like -fdump-tree-all. I didn't include dumps that
seemed identical to those prior.

It seems that rewrite_out_of_ssa() seems a likely culprit from examining
dumps .dce and .optimized.

Off Topic:

[snipped]

Various Files:

// tc1.c

static int
foo(int n) {
    static int yy = 0;


yy = n;

    return yy;
}


int
main(void)
{
    int pp;


    pp = foo(3);
    return pp;
}


// tc1.c.t02.original

;; Function foo (foo)
;; enabled by -tree-original



{
   static int yy = 0;
   yy = n;
   return <return-value> = yy;
}




;; Function main (main)
;; enabled by -tree-original



{
   int pp;
   pp = foo(3);
   return <return-value> = pp;
}


// tc1.c.t03.generic

;; Function foo (foo)

foo (n)
{
  static int yy = 0;


  yy = n;
  return yy;;
}



;; Function main (main)

main ()
{
  int T.1;
  int pp;


  T.1 = foo (3);
  pp = T.1;
  return pp;;
}



// tc1.c.t05.gimple

;; Function main (main)

main ()
{
  int retval.2;
  int T.1;
  int pp;


  {
    int n;
    int <UVecb0>;


    n = 3;
    {
      static int yy = 0;


      yy = n;
      {
        <UVecb0> = yy;
        goto <ULec40>;;
      };
    };
    <ULec40>:;;
    retval.2 = <UVecb0>;
  };
  T.1 = retval.2;
  pp = T.1;
  return pp;;
}



// tc1.c.t09.ssa

;; Function main (main)

main ()
{
  int retval.2;
  int T.1;
  int pp;


  {
    int n;
    int <UVecb0>;


    n_1 = 3;
    {
      static int yy = 0;


      yy = 3;
      <UVecb0>_4 = 3;
      goto <ULec40>;;
    };
    <ULec40>:;;
    retval.2_5 = 3;
  };
  T.1_6 = 3;
  pp_7 = 3;
  return 3;;
}


// tc1.c.t13.pre

;; Function main (main)

main ()
{
  int retval.2;
  int T.1;
  int pp;


  {
    int n;
    int <UVecb0>;


    (void)0;
    {
      static int yy = 0;


      yy = 3;
      (void)0;
      goto <ULec40>;;
    };
    <ULec40>:;;
    (void)0;
  };
  (void)0;
  (void)0;
  return 3;;
}


// tc1.c.t17.optimized

;; Function main (main)

main ()
{
  {
    yy = 3;
    <ULec40>:;;
  };
  return 3;;
}


Judd

[snipped]