Compiler optimizations

[Craig Black]

So I've been playing around with the pi program.  I ported it to C++ and
I've been doing some benchmarks with MSVC.  It seems that MSVC is a little
faster when SSE2 instructions are enabled.  It is slower when they are
disabled.  Which leads me to a question.  Does the D backend make use of SSE
2 intstructions?  I think the answer is yes but perhaps the optimizer is not
quite as sophisticated as MSVC yet.

Another question for someone who knows a lot about backend optimizations.
I've noticed that integer division is faster when the the divisor is a
constant.  How does the compiler optimize this?

Another thing.  I know that integer division is essentially a floating point
operation because there is no integer division instruction.  I also read
some on the internet and learned that Intel has a library that provides
fixed-point math routines, which provides a division operation that
outperforms floating-point division.  Then I thought to myself, "Why don't
compilers just use fixed-point division for dividing integers since it's
faster?"

I know some of you out there know way more than me so please all you smart
people give me some input.

-Craig