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Re: [PATCH] middle end, s390: optimization for builtin isnan
- From: Ian Lance Taylor <iant at google dot com>
- To: Wolfgang Gellerich<gellerich at de dot ibm dot com>
- Cc: gcc-patches at gcc dot gnu dot org
- Date: 06 Aug 2007 18:26:28 -0700
- Subject: Re: [PATCH] middle end, s390: optimization for builtin isnan
- References: <46B3247E.mailNXQ17I1BN@de.ibm.com>
Wolfgang Gellerich<gellerich@de.ibm.com> writes:
> This patch introduces a new target hook allowing to optimize the
> implementation of builtin function isnan on platforms like s390 where
> arithmetic operations set the condition code when the result was NaN. It
> bootstraps on Intel and s390 and does not introduce new test case failures.
It seems to me that we should handle this by treating isnan as a unary
operator which may be implemented in the MD file. E.g., implement
isnansf1 and isnandf1, with optabs. I don't see why a target hook is
the right thing here.
Ian