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0 pointszeusk2y ago0 comments

And?

> fact that downward bump is just not what the HW expects you to do.

What fact is this? and what does it have to do with stack being bounded? (bounds of stack are unknown to most micro architectural state and only stored in OS structures).

HW prefetchers support access pattern in either direction, so do load/store instructions (stm(fd)/ldm(fd); ltp/stp;)

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pizlonator2y ago· 1 in thread

The fact that stacks are bounded means you both push and you pop. Just as frequently as a function calls another one resulting in memory ops moving to lower addresses, functions also return causing memory ops to move back to higher addresses. Pushes and pops are balanced. Why do we know they are balanced? Because the stack is bounded.

So - the direction of stack growth isn’t interesting to prefetching strategy.

zeuskOP2y ago

Sure, but push/pop are not the only ways to access stack.

Moreover, I'm still wondering what you mean by this:

> Yeah I’m also amused that they didn’t get into the fact that downward bump is just not what the HW expects you to do.

What is this fact? Why does HW not expect you to bump addresses downwards?

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