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From: Martin Stromberg <Martin DOT Stromberg AT epl DOT ericsson DOT se>
Message-Id: <200304071443.QAA22691@lws256.lu.erisoft.se>
Subject: Re: Support for nan(0x[0-9a-f]*) in strto*, *printf
To: djgpp-workers AT delorie DOT com
Date: Mon, 7 Apr 2003 16:43:08 +0200 (MET DST)
In-Reply-To: <200304031505.RAA19060@lws256.lu.erisoft.se> from "Martin Stromberg" at Apr 03, 2003 05:05:08 PM
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Hi.

I said:
> I propose all strto*() do use an unsigned long long to store the
> mantissa (X) given in "nan(X)". If X > the maximum for float or
> double, set the mantissa to all-ones (we clamp the value to the
> maximum possible).
> 
> This will make ``strtof(sprintf(s, "%d", NAN), NULL)'' return a
> NaN. 

Am I confused or what? ``strtof(sprintf(s, "%d", NAN), NULL)'' would
return a NaN even in my earlier posted implementation. The only
difference is that the bits might be set differently.

Do you have any preferences (clamping or masking)?

> If *printf() will handle NaN in a double separately from long doubles
> this should make ``double value1 =
> extreme_cpu_use_generating_unusual_nans();
> double value2 = strtod(sprintf(s, "%d", value1), NULL)'' make the bit
> pattern of value1 == the bit pattern of value2.

This is sane though (IMO).


Right,

						MartinS