[Cfp-interest] pown

[Jim Thomas]

> On Sep 26, 2018, at 10:03 AM, Fred J. Tydeman <tydeman at tybor.com> wrote:
> 
> p754-241 vs cfp4x for pown
> 
> 754 has: pown(x, 0) is 1 for any x (even a zero, quiet NaN, or infinity)
> CFP has: pown(x, 0) returns 1 for all x not a signaling NaN. 
> 
> So, 754 requires pown(SNaN,0) to be 1 without signaling invalid.

Not what’s intended. 754 has a consensus ballot comment to change this to:

	pown(x,0) is 1 if x is not a signaling NaN

- Jim Thomas

> 
>                           754  CFP
> +inf, +even => +0, -even  +inf +inf OK
> +inf, +odd  => +0, -odd   +inf +inf OK
> +inf, -even => +0, +even    +0   +0 OK
> +inf, -odd  => +0, +odd     +0   +0 OK
> 
> -inf, +even => -0, -even  +inf +inf OK
> -inf, +odd  => -0, -odd   -inf -inf OK
> -inf, -even => -0, +even    +0   +0 OK
> -inf, -odd  => -0, +odd     -0   -0 OK
> 
> 
> ---
> Fred J. Tydeman        Tydeman Consulting
> tydeman at tybor.com      Testing, numerics, programming
> +1 (702) 608-6093      Vice-chair of PL22.11 (ANSI "C")
> Sample C99+FPCE tests: http://www.tybor.com
> Savers sleep well, investors eat well, spenders work forever.
> 
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