Most C/C++ compilers will optimize a loop like that away anyway ...

And what is that supposed to mean?

For basic math, C++ is ~10,000% faster than Python.

Where every single statement is interpreted, then it might be a factor of 100 slower. But certainly not 10,000.

*@*-mbp4:~$ gcc -O3 -otest test.c; echo "C:"; time ./test; echo "Perl:"; time perl test.pl; echo "Python:"; time python3 test.py C:
500000000500000000
real 0m0.149s
user 0m0.001s
sys 0m0.001s
Perl:
500000000500000000
real 0m8.287s
user 0m8.264s
sys 0m0.022s
Python:
500000000500000000
real 0m43.757s
user 0m43.635s
sys 0m0.115s

uint64_t a = 0;
for(uint64_t i = 0; i <= 1000000000; i++)
a += i;
printf("%llu\n", a);

$a = 0;
$a += $_ foreach (0 .. 1000000000);
print "$a\n";

a = 0
for x in range (1000000001):
a += x
print(a)

*@*-mbp4:~$ gcc -O3 -otest test.c; time ./test; time python3 test.py
1000000000
real 0m0.120s
user 0m0.007s
sys 0m0.001s
1000000000
real 0m30.205s
user 0m30.118s
sys 0m0.081s

- Suppose someone wants to estimate the probability that a model will respond to “My favorite sandwich is” with “peanut butter and jelly.” Here’s how to do that:
Prompt the model with “My favorite sandwich is” and look up the probability of “peanut” (let’s say it’s 20 percent).
Prompt the model with “My favorite sandwich is peanut” and look up the probability of “butter” (let’s say it’s 90 percent).
Prompt the model with “My favorite sandwich is peanut butter” and look up the probability of “and” (let’s say it’s 80 percent).
Prompt the model with “My favorite sandwich is peanut butter and” and look up the probability of “jelly” (let’s say it’s 70 percent).
Then we just have to multiply the probabilities like this: 0.2 * 0.9 * 0.8 * 0.7 = 0.1008