[Bug tree-optimization/63989] tree-ssa-strlen.c doesn't handle constant pointer plus and array refs if constant offset is smaller than known constant string length

[msebor at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=63989

Martin Sebor <msebor at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |msebor at gcc dot gnu.org
             Blocks|                            |83819

--- Comment #9 from Martin Sebor <msebor at gcc dot gnu.org> ---
In three out of the four test cases in comment #1 the strlen call is eliminated
(GCC 8 and 9).  The only one remaining is f3():

f3 (char * p)
{
  char * _1;
  long unsigned int _2;
  int _7;

  <bb 2> [local count: 1073741825]:
  __builtin_memcpy (p_4(D), "foobar", 7);
  MEM[(char *)p_4(D) + 2B] = 0;
  _1 = p_4(D) + 3;
  _2 = __builtin_strlen (_1);
  _7 = (int) _2;
  return _7;

}


Referenced Bugs:

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=83819
[Bug 83819] [meta-bug] missing strlen optimizations