Displaying 2 results from an estimated 2 matches for "fast_filter_t".
2008 Mar 29
2
[LLVMdev] Introducing a branch optimization and prediction pass
...is false.
What if we have memory reads, those might not be always be safe to move
out of the branch's body (because the condition could be required to
ensure the access is valid),
or it could actually decrease performance in case the guarding condition
is to prevent L2 cache misses, example:
if(fast_filter_table[value] == match && slow_filter_table[value] ==
match) { ... do something ... }
If we unconditionally read from slow_filter_table it could actually
reduce the performance (assume slow_filter_table is huge), and might not
be legal because we violate
the short-circuit evaluation.
(BTW, t...
2008 Mar 31
0
[LLVMdev] Introducing a branch optimization and prediction pass
...those might not be always be safe to
> move
> out of the branch's body (because the condition could be required to
> ensure the access is valid),
> or it could actually decrease performance in case the guarding
> condition
> is to prevent L2 cache misses, example:
> if(fast_filter_table[value] == match && slow_filter_table[value] ==
> match) { ... do something ... }
That's something to worry about later. :-)
>
>
> If we unconditionally read from slow_filter_table it could actually
> reduce the performance (assume slow_filter_table is huge), and mig...