[david-gpu]

> you don't actually want to force the decision of what is in the cache back to compile time, when the relevant information is better available at runtime

That is very context-dependent. In high-performance code having explicit control over caches can be very beneficial. CUDA and similar give you that ability and it is used extensively.

Now, for general "I wrote some code and want the hardware to run it fast with little effort from my side", I agree that transparent caches are the way.

[10000truths]

x86 provides this control with non-temporal load/store instructions.

[convolvatron]

that solves the pollution problem, but it doesn't pin cache lines. it also doesn't cover the case that ppc does where you want to assert a line is valid without actually fetching.