Delphi – How to disable the Formatter in Delphi 2010

The behavior of the $RTTI directive has been changed since XE6 because actually it was a bug because it was supposed to be local to the current unit (and it was actually documented as that since Delphi 2010).

Also it could have fatal affects using the directive at all even in one unit because due to the bug it basically switched a global flag affecting the following units (as in the order of compilation).

We are investigating the issue. In short, it depends on the potential mis-alignment (to 32 boundary) of the Integer referenced by a pointer. Need a little more time to have all of the answers... and a plan to address this.

Marco Cantù, moderator on Delphi Developers

Also reference Why are the Delphi zlib and zip libraries so slow under 64 bit? as Win64 libraries are shipped built without optimizations.

In the QP Report: RSP-9922 Bad ARM code produced by the compiler, $O directive ignored?, Marco added following explanation:

There are multiple issues here:

• As indicated, optimization settings apply only to entire unit files and not to individual functions. Simply put, turning optimization on and off in the same file will have no effect.
• Furthermore, simply having "Debug information" enabled turns off optimization. Thus, when one is debugging, explicitly turning on optimizations will have no effect. Consequently, the CPU view in the IDE will not be able to display a disassembled view of optimized code.
• Third, loading non-aligned 64bit data is not safe and does result in errors, hence the separate 4 one byte operations that are needed in given scenarios.