[fpc-devel] FillWord, FillDWord and FillQWord are very poorly optimised on Win64 (notsureabout x86-64 on Linux)

[J. Gareth Moreton]

Okay, I'm about to start attempting to implement my versions of FillWord, FillDWord and FillQWord (along with 
some fixes to bugs that I noticed in my code in the interim)... given that I have to push and pop RDI to use 
REP STOSQ etc, what do I need to do in order to ensure SEH handles the stack frame correctly?  All the other 
assembler functions that have FillChar/Move etc don't do any pushing or popping.

J. Gareth "Kit" Moreton