Hi,

If I have a .pas unit and forgot to specify the compiler mode line

   {$mode objfpc}{$H+}

what does FPC default to? Compiler Mode? Longstring or Shortstring?

I wrote a string tokenizer and did some time trials against an old tokenizer I used. First I forgot to include the compiler mode line above and did some test runs. I then noticed my mistake and added in that line and did some more test runs. The second set of tests where on avg 10% faster!

After some more testing I realized it is the {$H+} that gave me the performance boost. What does FPC default to? Why not default to {$H+} ?

Lazarus added the following compiler parameters:
---------------------------------------------------- -S2cgi -OG1 -gl -vewnhi -l
-Fu/opt/lazarus/components/fpcunit/lib/i386-linux/ -Fu/opt/lazarus/components/synedit/units/i386-linux/ -Fu../../3rdParty/tiOPF2/Source/Compilers/FPC/lib/i386-linux/ -Fu/home/graemeg/programming/3rdParty/FBlib/lib/i386-linux/ -Fu/opt/lazarus/lcl/units/i386-linux/
-Fu/opt/lazarus/lcl/units/i386-linux/gtk/
-Fu/opt/lazarus/packager/units/i386-linux/ -Fu. -ofpcunitproject1 -dUseCThreads -dLCL -dLCLgtk
----------------------------------------------------

Graeme Geldenhuys wrote

If I have a .pas unit and forgot to specify the compiler mode line {$mode objfpc}{$H+} what does FPC default to? Compiler Mode? Longstring or Shortstring?

Shortstring. {$h+} is not longstring, but ansistring.

After some more testing I realized it is the {$H+} that gave me the performance boost. What does FPC default to? Why not default to {$H+} ?

Backwards compatibility. There are also many situations where ansistrings are slower than shortstrings.

Jonas

Ah, I see... Thanks for the quick reply.

Graeme.