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* [Bug tree-optimization/59209] builtin memcpy in inlined function is not optimized away if count is derived from src pointer difference
       [not found] <bug-59209-4@http.gcc.gnu.org/bugzilla/>
@ 2013-11-20 10:37 ` glisse at gcc dot gnu.org
  2013-11-20 10:40 ` rguenth at gcc dot gnu.org
  1 sibling, 0 replies; 2+ messages in thread
From: glisse at gcc dot gnu.org @ 2013-11-20 10:37 UTC (permalink / raw)
  To: gcc-bugs

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=59209

--- Comment #1 from Marc Glisse <glisse at gcc dot gnu.org> ---
In test_copy2, we get:

  _2 = x_1(D) + 1;
  src_end.1_8 = (long int) _2;
  src_start.2_9 = (long int) x_1(D);
  _10 = src_end.1_8 - src_start.2_9;
  _11 = (long unsigned int) _10;

This reminds me of PR 58742: we are failing to simplify basic arithmetic on
pointers.


^ permalink raw reply	[flat|nested] 2+ messages in thread
* [Bug tree-optimization/59209] builtin memcpy in inlined function is not optimized away if count is derived from src pointer difference
       [not found] <bug-59209-4@http.gcc.gnu.org/bugzilla/>
  2013-11-20 10:37 ` [Bug tree-optimization/59209] builtin memcpy in inlined function is not optimized away if count is derived from src pointer difference glisse at gcc dot gnu.org
@ 2013-11-20 10:40 ` rguenth at gcc dot gnu.org
  1 sibling, 0 replies; 2+ messages in thread
From: rguenth at gcc dot gnu.org @ 2013-11-20 10:40 UTC (permalink / raw)
  To: gcc-bugs

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=59209

Richard Biener <rguenth at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |RESOLVED
         Resolution|---                         |DUPLICATE

--- Comment #2 from Richard Biener <rguenth at gcc dot gnu.org> ---
We simply are not able to optimize x + 1 - x to 1.  See also PR58742
for which I think this is a dup.

  _2 = x_1(D) + 1;
  src_end.1_8 = (long int) _2;
  src_start.2_9 = (long int) x_1(D);
  _10 = src_end.1_8 - src_start.2_9;
  _11 = (long unsigned int) _10;
  __builtin_memcpy (&r, x_1(D), _11);

later on RTL we optimize the size argument to 1 but that's too late.

*** This bug has been marked as a duplicate of bug 58742 ***


^ permalink raw reply	[flat|nested] 2+ messages in thread
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     [not found] <bug-59209-4@http.gcc.gnu.org/bugzilla/>
2013-11-20 10:37 ` [Bug tree-optimization/59209] builtin memcpy in inlined function is not optimized away if count is derived from src pointer difference glisse at gcc dot gnu.org
2013-11-20 10:40 ` rguenth at gcc dot gnu.org

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