Re: does a safer language mean it is slower to run?

["Jeffrey R.Carter" <spam.jrcarter.not@spam.acm.org.not>]

On 2023-06-08 05:55, Nasser M. Abbasi wrote:
> 
> Some in that thread seem to argue that a safer language
> will/could be slower than otherwise.
> 
> Since Ada is known to be one of the safest languages,
> do others here feel there is any truth to this?

Equivalent programs in compiled, non-GC languages have equivalent execution 
times. Robert Dewar famously had a set of equivalent Ada and C programs that 
produced identical machine code when compiled with gcc. So this is false.

The problem is getting equivalent programs. If the safe language includes 
run-time checks, then equivalent checks must be manually added to the unsafe 
language. Ada.Text_IO is not equivalent to C's I/O facilities. And so on.

Once consequence of this is that both programs will be equally correct. What is 
usually compared is a correct (run-time checks) program in the safe language to 
an incorrect (no run-time checks) program in the unsafe language.

About optimization, Tartan made its living selling highly optimizing C compilers 
for TI chips, which came with a free C compiler. They also made highly 
optimizing Ada compilers, which did a better job of optimization than their C 
compilers. This was documented in

C vs Ada: arguing performance religion 
(https://dl.acm.org/doi/10.1145/216578.216583)

which discusses four advantages Ada (83) has over C for optimization.

See also

Ada Outperforms Assembly: A Case Study 
(https://www2.seas.gwu.edu/~adagroup/sigada-website/lawlis.html)

TI bought Tartan and sold its Ada compilers to DDC-I.

-- 
Jeff Carter
"Monsieur Arthur King, who has the brain of a duck, you know."
Monty Python & the Holy Grail
09