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From: "gabravier at gmail dot com" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug tree-optimization/94913] Failure to optimize not+cmp into
 overflow check
Date: Sat, 02 May 2020 02:18:45 +0000
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https://gcc.gnu.org/bugzilla/show_bug.cgi?id=3D94913

--- Comment #1 from Gabriel Ravier <gabravier at gmail dot com> ---
The same thing happens for this code :

bool f(unsigned x, unsigned y)
{
    return (x - y - 1) >=3D x;
}

LLVM outputs this :

f(unsigned int, unsigned int):
  cmp esi, edi
  setae al
  ret

GCC outputs this :

f(unsigned int, unsigned int):
  mov eax, edi
  sub eax, esi
  sub eax, 1
  cmp eax, edi
  setnb al
  ret=