R3 Math Speed
Ticket #0001338 suggests that math speed is reduced in R3 as compared to R2. Let me comment on that.
First, all R3 releases are alpha test builds which means they're not optimized builds. However, if I enable compiler optimizations, I see that R3 is slightly faster than R2.
Using the example code that was posted (fair code because it is 64 bits in both R2 and R3):
dt [loop 20'000'000 [a + b * a / b]]
The timings on x86 in XP are:
R3.A94: 0:00:14.218 (no opts)
R3.A95o1: 0:00:13.920443 (some opts)
R3.A95o2: 0:00:13.858737 (more opts)
So, for now, while in alpha, let's focus on the last few language-related elements of R3, so we can move to the next release stage.
Also, for higher performance math, rebcode functions should be available in R3.1. And, if the R3 developer community feels inclined to support compiled functions (yes, such support would be in the host), greater levels of performance could be achieved.