Re: Not good for Ada endorsement

[Lucretia <laguest9000@googlemail.com>]

On Thursday, 15 July 2021 at 16:56:40 UTC+1, Jeffrey R. Carter wrote:
> On 7/15/21 5:13 PM, Lucretia wrote: 
> > 
> > I managed to get just under 4000 passes with a 1 bit array, but not using Ada's packed array. That's actually the slowest method, strangely.
> So you have an array of a modular type, calculate an index and bit within it, 
> mask out that bit, and compare it to zero? I would have thought an unpacked 
> array of Boolean would be fastest. 

Doesn't seem to be. Also, the guy is using the packed bit as the final test of all the languages.

> A packed array of Boolean requires all the operations above, plus shifting the 
> bit to the LSB and treating the result as a Boolean, so it may not be that 

Don't need to shift to the LSB, only need to shift the 1 to the bit location you want to test, invert and then check against 0.

> surprising that it's slower. 

I know. I  would've thought the compiler would've handled the packed array as a special case and optimised as much as possible there.