Self-modifying code! The real kind!

[Era Scarecrow via Digitalmars-d]

On Friday, 7 April 2017 at 20:43:52 UTC, Stefan Koch wrote:
> On Thursday, 6 April 2017 at 05:36:52 UTC, Swoorup Joshi wrote:
>> Self-modifying might be the answer to all sorts of performance 
>> problems due to branching.
>
> No it's not! You are throwing away your i-cache AND mess up the 
> branch prediction.

  From the opening statement it looks and sounds more like loading 
and unloading DLL files... rather than self-modifying code.

  Self modifying code isn't really that practical anymore, the 
best example working is compressed executables (UPX and similar), 
but those only expand optimized code from a compressed cache and 
then changes the block to executable, it doesn't really modify 
the code at all.

  Perhaps an actual use case for self-modifying code would be to 
give you a quick & dirty compile for a function, and then work on 
optimizing it, then switch the calls appropriately to the new 
function once it's optimized, which is more useful to for say JIT 
circumstances and emulation, and less in statically known source 
code.