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Re: (0 <= i && i < N) is not "backwards"

From: Noah Lavine
Subject: Re: (0 <= i && i < N) is not "backwards"
Date: Mon, 25 Mar 2013 11:28:11 -0400

On Mon, Mar 25, 2013 at 11:09 AM, Eli Zaretskii <address@hidden> wrote:
> From: Noah Lavine <address@hidden>
> Date: Mon, 25 Mar 2013 10:58:28 -0400
> Cc: Paul Eggert <address@hidden>, Andreas Schwab <address@hidden>,
>       Emacs development discussions <address@hidden>
> To continue a tangent, if adding an explicit isnan() makes the code run any
> slower, I think you should file a bug with GCC to get that fixed.

I don't think GCC is a problem: isnan is a builtin function there, so
even a function call overhead is spared.

Oh, that's good. I didn't know how it was implemented.

I mean that GCC should be able to convert ((x > 0) || isnan(x)) to !(x <= 0) if the second _expression_ is actually faster. It seems like a fairly simple rewrite.

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