spring/spring — comment on commit 39496262fb39eb169f28d908ed4c31425b4b901a
File:  line 0
By Kaylewt:

Thought so.

Now for my hypothesis: since both synced and unsynced code access these all the time (eg for ray-ground intersection), the access pattern will be batch-alternating every ~33ms in ST, and look more random in MT. Thus in MT dynamic branch prediction will be useless, while in ST it _might_ learn to favor the false-branch (but BP behavior/speed in a _big_ program like Spring depends on too many factors to go by results of synthetic tests, whereas the performance of the branchless method is always known).