i386 vs amd64

[Thomas Mueller]

> On Thu, Nov 29, 2012 at 2:57 PM, Bill Tillman <btillman99 at yahoo.com> wrote:

> > i386 will not see anything above 4 GB


> Actually you *can* give access to >4Gb RAM for your system: PAE allows you
> to use 36 bits instead of 32 to address your memory (and supported till
> Pentium Pro) but that is only for OS (32bit apps would see 4Gb only).

> Anyway, I have not seen any troubles with 64bit installations.

> Ilya.

How does the system know what is OS and what is 32-bit apps?

Where would GCC fit in this regard, or Clang for that matter?

Tom