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Re: [Chicken-hackers] [PATCH] Fix undefined behaviour of shifting left s

From: John Cowan
Subject: Re: [Chicken-hackers] [PATCH] Fix undefined behaviour of shifting left signed values
Date: Sun, 21 Jun 2015 17:11:51 -0400
User-agent: Mutt/1.5.20 (2009-06-14)

Peter Bex scripsit:

> - We are using left shifts on signed types.  According to the C spec
>    this behaviour is undefined (which is completely retarded, IMHO).
>    The even more retarded fix is to simply cast to unsigned and back to
>    signed whereever this is done.  

Yeah, it reflects old processors.

> - We are dividing floating-point numbers by zero, which is apparently
>    undefined.  

Don't worry about that.  Any C compiler that ignored IEEE 754 constraints,
even though C doesn't assume them, would be ostracized by numerical

John Cowan        address@hidden
And it was said that ever after, if any man looked in that Stone,
unless he had a great strength of will to turn it to other purpose,
he saw only two aged hands withering in flame.   --"The Pyre of Denethor"

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