Re: [PATCH] frange: dump hex values when dumping FP numbers.

[Jeff Law <jeffreyalaw@gmail.com>]

On 9/22/22 10:49, Aldy Hernandez via Gcc-patches wrote:
> It has been suggested that if we start bumping numbers by an ULP when
> calculating open ranges (for example the numbers less than 3.0) that
> dumping these will become increasingly harder to read, and instead we
> should opt for the hex representation.  I still find the floating
> point representation easier to read for most numbers, but perhaps we
> could have both?
>
> With this patch this is the representation for [15.0, 20.0]:
>
>       [frange] float [1.5e+1 (0x0.fp+4), 2.0e+1 (0x0.ap+5)]
>
> Would you find this useful, or should we stick to the hex
> representation only (or something altogether different)?
>
> Tested on x86-64 Linux.
>
> gcc/ChangeLog:
>
> 	* value-range-pretty-print.cc (vrange_printer::print_real_value): New.
> 	(vrange_printer::visit): Call print_real_value.
> 	* value-range-pretty-print.h: New print_real_value.

The big advantage of the hex representation is you can feed that back 
into the compiler trivially and be confident the bit pattern hasn't 
changed.   I've found it invaluable when doing deep FP analysis.


jeff