If Zortech C++ and dmc++ are fast, why is dmd's asm slow?

[Abdulhaq]

On Sunday, 30 May 2021 at 12:43:22 UTC, Abdulhaq wrote:
> On Saturday, 29 May 2021 at 23:43:48 UTC, James Lu wrote:
>> On Saturday, 29 May 2021 at 23:36:34 UTC, Adam D. Ruppe wrote:
>>> On Saturday, 29 May 2021 at 23:34:47 UTC, James Lu wrote:
>>>> If Zortech C++ and dmc++ are fast, why is dmd's asm slow? I 
>>>> thought they used the same machine code backend.
>>>
>>> They were fast in 1988. Even in 1998.
>>>
>>> But since then they've only gotten a little better, whereas 
>>> the competition has gotten a LOT better.
>>
>> That makes sense.
>>
>> Why does DMD only have a -O flag, not a -O2?
>>
>> The competition got heavier– slower compiles, too.
>>
>> I wonder if it could be possible to get some CS PhD candidate 
>> to work on dmc++ to bring its backend up to modern standards.
>
> Why stop at -O2? The languages of the future will go to -O11.

OK I was kidding, but this is interesting, from Steve Sinofsky of 
early Visual C++:

"While I wielded a great technology buzzsaw, I was also applying 
Microsoft’s perspective, not necessarily what Lotus was looking 
to accomplish or what reviewers would see. For example, my focus 
on shared code came straight from BillG as that was his hot 
button. The Lotus products clearly hadn’t focused on that at all. 
I thought they were “wrong” not simply different. This mismatch 
was something I had seen in the evaluations of Borland C++ versus 
Microsoft VC++. For example, Borland had a compiler optimization 
switch “/O” that was, basically, “make this code as fast as 
possible by enabling all the best optimizations.” To us 
compiler-heads at Microsoft, we thought of this as technical 
nonsense because each of the myriad potential optimizations meant 
something unique to the programmer (literally the entire alphabet 
of command line switches), but it had captivated reviewers. I 
came to champion (and push) the addition of “/O” for our complier 
and it turned out that it worked with reviewers. When Ami Pro, 
the Lotus SmartSuite word processor, demonstrated its new 
ease-of-use features under the umbrella of working together, it 
similarly captured the attention of reviewers, even if deep down 
in technical details it didn’t make much sense."

I'm really enjoying his blog ATM, a history of his time at MS, 
recommended:

https://hardcoresoftware.learningbyshipping.com/p/031-synchronizing-windows-and-office