Compiler versions on different platforms

Hello All,

I am looking to compile PostgreSQL 8.3.7 on following
operation systems with their corresponding compilers

1) Windows => Cl.exe from visual studio

2) Linux => gcc ( What is the oldest version which is okay with this
setup ?

3) Solaris 9/10+ => cc and gcc ( same question as above )

4) HP-UX 11i+=> aCC and gcc ( same question as above )

5) AIX 5.3 + => xlC and gc ( same question as above ).

I was able to compile on all of the platforms but I want to know about
minimum and recommended version requirements for these systems. I am
concerned about performance of these binaries and looking to achieve

performance of these binary as close as possible to binaries provided at
PostgreSQL website. Or if somebody can point out which binaries
EnterpriseDB uses for their binaries it will be great.

Thanks & Regards,

Vikram