[fpc-pascal] FPC Graphics options?

[Nikolay Nikolov]

On 05/19/2017 03:54 AM, Ryan Joseph wrote:
>> On May 18, 2017, at 10:40 PM, Jon Foster <jon-lists at jfpossibilities.com> wrote:
>>
>> 62.44      1.33     1.33                             fpc_frac_real
>> 26.76      1.90     0.57 MATH_$$_FLOOR$EXTENDED$$LONGINT
>> 10.33      2.12     0.22                             FPC_DIV_INT64
> Thanks for profiling this.
>
> Floor is there as I expected and 26% is pretty extreme but the others are floating point division? How does Java handle this so much better than FPC and what are the work arounds? Just curious. As it stands I can only reason that I need to avoid dividing floats in FPC like the plague.
Java is a JVM, which generates bytecode, which isn't CPU specific and 
comes with a JIT compiler, which compiles the bytecode to native code, 
when the program is run, so it can always make use of the instruction 
set, supported by the CPU you're using. But, of course, launching the 
application becomes much slower. In FPC, if you want to use SSE and 
avoid the x87 FPU, you have to compile with a specific compiler options 
and forfeit the option for your executable to run on non-SSE capable 
CPUs, because FPC generates native code. If you want to keep 
compatibility and support modern instruction set extensions, you need to 
compile different executables for different instruction sets and make a 
launcher .exe, which detects the CPU type and runs the appropriate 
executable. The default options for the i386 compiler is to target the 
Pentium CPU, which does not have SSE. This gives most compatibility and 
least performance, but that's what's appropriate for most users, because 
for most desktop applications, CPU speed is no longer an issue. Only 
very specific tasks, such as software 3D rendering need high CPU 
performance, and people doing that stuff, usually know very well their 
compiler options and how to enable support for modern instruction 
extensions for maximum performance. Of course, people coming from a Java 
background might not be used at all to having to do this kind of stuff, 
but it's really not that hard.

Nikolay