But I'm open to any ideas you may have as to how we could avoid using floats, yet not run into the overflow situations so easily. We could probably use division somewhere but I don't think that's actually any better performance-wise.
It is, when implemented via bit-shifts (very cheap). I know wine is written in pure C, but with a little C++ template magic you should be able to have fixed-point math that acts like floating, only having the compiler take care of the binary point at compile-time using the type system, and emitting only integer operations. Still wouldn't be as efficient as hand-designed fixed-point pumped through the optimizing compiler. I'm pretty sure ints are still much better performance-wise. That article you cited is not telling the whole story; no operation on a modern CPU is executed in a single cycle. The aggregate throughput when considering optimal pipelining may be one float instruction per cycle... but integer operations routinely achieve several (on a Core 2 I believe up to four instructions can be started into the pipelines per cycle, per core). There's also pipeline stalls and flushes to consider, where I believe further investigation will again show much bigger performance hits on floating-point. And no mention of SIMD was made whatsoever, which is capable of the highest performance in every discussion I've seen. Furthermore SIMD has built-in support for things like integer-multiply-keeping-only-the-most-significant-half and multiply-add, at least on x86 architecture, which if I'm not mistaken is still a wine requirement for running x86 PE files. And when you try to save space by using 32-bit float, you lose everywhere. 32-bit floating-point store involves rounding and is slow. As a result, compilers maintain high precision as long as possible, which means you lose repeatability (integer expressions tend to give the same results with or without optimizations, float -- do not). If you go to 64-bit floats, then you should compare against the range of 64-bit integers, which modern CPUs also support at full speed for basic operations.
