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Re: [Bug tree-optimization/15452] [tree-ssa] Optimize cascaded a = a == 0;
- From: Daniel Berlin <dberlin at dberlin dot org>
- To: gcc-bugzilla at gcc dot gnu dot org
- Cc: gcc-bugs at gcc dot gnu dot org
- Date: Thu, 24 Aug 2006 10:43:07 -0400
- Subject: Re: [Bug tree-optimization/15452] [tree-ssa] Optimize cascaded a = a == 0;
- References: <bug-15452-5009@http.gcc.gnu.org/bugzilla/> <20060824042755.1536.qmail@sourceware.org>
pinskia at gcc dot gnu dot org wrote:
> ------- Comment #6 from pinskia at gcc dot gnu dot org 2006-08-24 04:27 -------
> Another interesting case would be (but which could be handled by VRP):
> int
> foo (int a)
> {
> a = a!=0;
> a = a!=0;
> a = a!=0;
> a = a!=0;
> a = a!=0;
> return a;
> }
> Which should be optimized to:
> int foo(int a) { return a!=0;}
>
>
Uh, FRE could also optimize this to the same thing, I just don't
remember whether it bothers to look at conditionals as eliminable
expressions.