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From: "pinskia at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug tree-optimization/113411] New: ABS<a>*ABS<b> can be simplified to ABS<a*b>
Date: Tue, 16 Jan 2024 00:23:52 +0000	[thread overview]
Message-ID: <bug-113411-4@http.gcc.gnu.org/bugzilla/> (raw)

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=113411

            Bug ID: 113411
           Summary: ABS<a>*ABS<b> can be simplified to ABS<a*b>
           Product: gcc
           Version: 14.0
            Status: UNCONFIRMED
          Keywords: missed-optimization
          Severity: enhancement
          Priority: P3
         Component: tree-optimization
          Assignee: unassigned at gcc dot gnu.org
          Reporter: pinskia at gcc dot gnu.org
  Target Milestone: ---

Take:
```

static inline int abs(int a)
{
  signed b = a;
  if (a < 0)
    b = -b;
  return b;
}

int foo1(int a, int b)
{
   return abs(a) * abs(b);
}
```

foo1 can be simplified down to `abs(a*b)`.  Note I think this is only valid for
signed overflowable types and not valid with -fwrapv (but I could be wrong).
Maybe ok for real types with -ffast-math.

             reply	other threads:[~2024-01-16  0:23 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2024-01-16  0:23 pinskia at gcc dot gnu.org [this message]
2024-01-16  8:13 ` [Bug tree-optimization/113411] " rguenth at gcc dot gnu.org
2024-01-21  9:58 ` pinskia at gcc dot gnu.org

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