On Thursday, 31 March 2022 at 18:40:52 UTC, deadalnix wrote:
> On Thursday, 31 March 2022 at 06:31:32 UTC, Walter Bright wrote:
>> You see a similar thing when 32 bit compilation does 64 bit arithmetic:
>>
>> [...]
>>
>> So, yeah, supporting 128 bit arithmetic in the codegen has significant advantages. 3 multiplies and 2 adds.
>>
>> Having the compiler recognize the `mul` function as a builtin would enable this code gen for 128 bits.
>
> So now that you just killed the library solution by having the compiler specially recognize it, can we have cent/ucent?
>
> Honestly, I don't care if DMD forward the operation to something in druntime, that would at least allow me to have good codegen on LDC/GDC.

We can do the same as complex numbers here.

enum __c__int128 : core.int128.Cent;
enum __c__uint128 : core.int128.Cent;

Later, when cent/ucent have been dropped as keywords.

alias cent = __c__int128;
alias ucent = __c__uint128;

On Thursday, 31 March 2022 at 22:30:48 UTC, kinke wrote:
> On Thursday, 31 March 2022 at 18:40:52 UTC, deadalnix wrote:
>> Honestly, I don't care if DMD forward the operation to something in druntime, that would at least allow me to have good codegen on LDC/GDC.
>
> The existing generic software implementation is still useful for CTFE.

Yep, they were all written to be CTFE-friendly.

Another advantage to core.int128 is any soft implementation of a 128 bit integer does not need to concern itself with the correctness of the arithmetic - just the user side of the integer type.

I also like core.int128 does not import anything else, making it a true leaf module.

Edit: Oh darn, it imports core.bitop!

On Saturday, 2 April 2022 at 19:06:01 UTC, Walter Bright wrote:
> Another advantage to core.int128 is any soft implementation of a 128 bit integer does not need to concern itself with the correctness of the arithmetic - just the user side of the integer type.
>
> I also like core.int128 does not import anything else, making it a true leaf module.
>
> Edit: Oh darn, it imports core.bitop!

It's only bsr, the compiler inlines that into one instruction. ;-)

On 4/2/2022 2:40 PM, Iain Buclaw wrote:
> On Saturday, 2 April 2022 at 19:06:01 UTC, Walter Bright wrote:
>> Another advantage to core.int128 is any soft implementation of a 128 bit integer does not need to concern itself with the correctness of the arithmetic - just the user side of the integer type.
>>
>> I also like core.int128 does not import anything else, making it a true leaf module.
>>
>> Edit: Oh darn, it imports core.bitop!
> 
> It's only bsr, the compiler inlines that into one instruction. ;-)

I know. I was dreading doing the work you did for divide, glad you picked up the flag! I had done the equivalent for DMC's long divide long ago.

On 4/1/2022 7:23 AM, mee6 wrote:
>> Whoever does it first gets the glory :-)
> 
> I'd do it for money lol

What the hell, I'm tired of the jawboning and did it for the greater glory:

https://github.com/dlang/phobos/pull/8426

On 3/25/2022 4:33 PM, Murilo wrote:
> I have been waiting for years now, can't you guys just add these 2 types to the language?

Well, I tried.

https://github.com/dlang/phobos/pull/8426