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From: "xry111 at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug tree-optimization/112457] Possible better vectorization of different reduction min/max reduction
Date: Tue, 02 Jan 2024 16:03:38 +0000	[thread overview]
Message-ID: <bug-112457-4-TxKCoSJfq3@http.gcc.gnu.org/bugzilla/> (raw)
In-Reply-To: <bug-112457-4@http.gcc.gnu.org/bugzilla/>

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=112457

Xi Ruoyao <xry111 at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |xry111 at gcc dot gnu.org

--- Comment #4 from Xi Ruoyao <xry111 at gcc dot gnu.org> ---
There is also:

double
test (double *p)
{
  double ret = p[0];
  for (int i = 1; i < 4; i++)
    ret = __builtin_fmin (ret, p[i]);
  return ret;
}

This is not vectorized.

And

double
test (double *p)
{
  double ret = __builtin_inf(); /* or __builtin_nan("") */
  for (int i = 0; i < 4; i++)
    ret = __builtin_fmin (ret, p[i]);
  return ret;
}

is compiled to:

  _16 = .REDUC_FMIN (vect__4.7_17);
  _22 = .REDUC_FMIN ({  Inf,  Inf,  Inf,  Inf }); 
  _20 = .FMIN (_16, _22); [tail call]
  return _20;

So there is an redundant .FMIN operation.

  parent reply	other threads:[~2024-01-02 16:03 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-11-09 12:27 [Bug c/112457] New: " juzhe.zhong at rivai dot ai
2023-11-09 12:29 ` [Bug c/112457] " juzhe.zhong at rivai dot ai
2023-11-09 12:45 ` [Bug tree-optimization/112457] " rguenth at gcc dot gnu.org
2024-01-02  8:58 ` juzhe.zhong at rivai dot ai
2024-01-02 16:03 ` xry111 at gcc dot gnu.org [this message]
2024-01-08  9:00 ` rguenth at gcc dot gnu.org

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