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Reply to @david_chisnall@infosec.exchange
Sun Microdevil Pte Ltd@koakuma@uwu.social (2026-08-17 02:20:53)
@david_chisnall The latter part is exactly how the v9 ISA book recommends it to be used (though it uses branches as an example), if my memory serves me right

I dunno how much of an impact it would have on modern heavily-optimizing implementations, though, in particular because those things would already speculate the loads anyway, no?
---Reply---
Sun Microdevil Pte Ltd@koakuma@uwu.social (2026-08-17 02:29:46)
@david_chisnall Also I just noticed that you can (somewhat hackily) impleement a `ptr ? *ptr : default` with like

ld [ptr] #ASI_PNF, val
movrz ptr, default, val

But idk how much of an improvement would this be over just letting the predictor speculate the ptr != NULL case (hopefully NULLs would be rare, wouldn't they?)