Hello,
I just wanted to optimize a byte -> index lookup, by using a 256
element table instead of using [1, 2, 3].countUntil(x) and I was
amazed what I've found.
My solution lookup[x] was not faster at all, because LDC2
amazingly optimized the linear search to a jump table.
Anyone please can tell me, how it is possible?
I looked inside the countUntil() template and I see no static ifs
for compile time optimizations.
Is it true that: The compiler notices that there is a while loop
on a static compile time array and it is clever enough to solve
all the calculations in compile time and generate a completely
unrolled loop? Then the optimizer transforms it to the jump table
and do it with "jmp rax" ?
If I'm right, this is not just std library magic, it works even
with my own template functions.
I'm also getting crazy long compile times, so this gotta be the
case :D
Thank You in advance.
