[fpc-devel] TViHashList and TFPHashObjectList in compiler

[Juha Manninen]

I studied the compiler internals by debugging it.

Does TViHashList have any documentation or diagram or anything? It 
differs from many other hash maps. Is it based on some other code which 
is documented?

TFPHashObjectList is based on it. It is used for all symbols but also 
for predefined directives. How about setting its capacity initially in 
such cases, like:

      procedure InitScanner;
        begin
          turbo_scannerdirectives:=TFPHashObjectList.Create;
+        turbo_scannerdirectives.Capacity:=150;

Less GetMem() calls, copying data and recalculating hashes.

For predefined directives and tokens a "perfect hash" would be perfect. 
:)  I mentioned it in this MR

https://gitlab.com/freepascal.org/fpc/source/-/merge_requests/126


Juha