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Re: A new patch for floating point conditional mov on PPo
- To: hjl at lucon dot org (H.J. Lu)
- Subject: Re: A new patch for floating point conditional mov on PPo
- From: Jeffrey A Law <law at cygnus dot com>
- Date: Fri, 19 Jun 1998 21:20:51 -0600
- cc: john at feith dot com (John Wehle), egcs-patches at cygnus dot com
- Reply-To: law at cygnus dot com
In message <m0yjqpP-00026AC@ocean.lucon.org>you write:
> I have verified that the current notice_update_cc will clear cc0 for
> all conditional moves. Given
That wasn't the point. What the "current" notice_update_cc does is
overly conservative. We don't want to depend on other parts of the
compiler having overly conservative code generation -- later when someone
makes notice_update_cc less conservative they'll expose a latent bug
in your code.
It's better to make your code more robust now than depend on the overly
conservative nature of other code and have a latent, hard to find bug
show up later. That's basic software engineering.
(I use "current" since this message was referring to the code before
a recent change from John which makes notice_update_cc less conservative).
jeff