TLB Hit 💥: Recent Episodes
JF Bastien & Chris Leary
- What is it we know statically?
- What's effectively discoverable only at runtime?
- How do we tell "the machine" (compiler and/or hardware):
- Things we know to be true...
- Things we expect to be true...
- Things we expect to be true but want to do something about when it's not...
- Things we have no idea about!
- How do we collect that information that we have no idea about?
- What happens if we're wrong? What if the workload is inherently irregular?
- In the limit, random noise could drive our control decisions!
- We talked a bit about precise vs imprecise exceptions before and automatic reordering, and we've mentioned vector machines and auto-vectorization.
- All falls into the broader theme here, but we're always questioning what we can actually cover in an hour...
- We'll try to give it a go for a subset of these things!
-
Time is often the limiting factor.
-
The episode title is the thing that we often macro define as
#define UNLIKELY - In C/C++ code you might say "this control condition is unlikely", and say
if (UNLIKELY(condition)) - In C++20 there was added these
[[likely]]and[[unlikely]]annotations that do the same thing, but with more square brackets, so clearly better!
What happens when you type https://tlbh.it in your browser's address bar, and press enter?