On 03/10/2020 18:43, J. Gareth Moreton via fpc-devel wrote: > Sounds like a fun thing to research, that's for sure. Thanks Jonas. > > I'm under the impression that exception code tends to be separated > anyway, so it can't easily be separated much further.
Implicit exception code, yes, but explicit try/except blocks can appear anywhere. > Code that executes if, say, a LongInt variable equals "-1" might be cold > code, especially as that's often an error flag and is otherwise just one > value out of 2^32 possibilities (i.e. statistically unlikely to be > True), although it's tricky to know if an assumption is correct or not > given an arbitrary block of code, and what the penalty is if code that's > marked as cold is actually hot. There's a pretty famous paper that investigated what kind of checks often (in about 80% of the cases) result in taken/non-taken branches. You can find it at https://www.classes.cs.uchicago.edu/archive/2017/fall/32001-1/papers/ball-larus-branch-predict.pdf You will indeed get penalties from mispredictions, but you can be as conservative as you want. Jonas _______________________________________________ fpc-devel maillist - fpc-devel@lists.freepascal.org https://lists.freepascal.org/cgi-bin/mailman/listinfo/fpc-devel
