SIMD/intrinsincs questions

[Walter Bright]

bearophile wrote:
> Walter Bright:
> 
>> Modern compilers don't do much better. The point of diminishing
>> returns was clearly reached.
> 
> I routinely see D benchmarks that are 2+ times faster with LDC
> compared to DMD.

Have to be careful about benchmarks without looking at why. A few months 
ago, a benchmark was posted here purportedly showing that dmd was awful 
at integer math. Turns out, the problem was entirely in the long divide 
function, not the code generator at all. I rewrote the long divide 
helper function, and problem solved.