topic Re: running 32-bit apps on Itanium in Operating System - Linux

running 32-bit apps on Itanium

C R S — Thu, 28 Sep 2006 12:11:50 GMT

Ok,
There seems to be some debate about compiling and running 32-bit applications on an Itanium server running Linux.

I've been told that it can't or shouldn't be done. That you can't compile but you can run a 32-bit application under an emulation layer with a hit on performance.

Well, a co-worker has just recently downloaded the 32-bit source code of several utilities and compiled them on a Itanium 2620 running EL4 and they are working fine. So now I'm not sure what to think.

any help out there?

TIA

CRS

Re: running 32-bit apps on Itanium

Sameer_Nirmal — Thu, 28 Sep 2006 15:19:47 GMT

Well, it appears that initially it was not possible to compile/port the 32 bit code in Linux 64-bit OS environment until porting compilers and tools were release to assist the porting on Itanium.

The execution of 32 bit code on Windows and Linux is supported by IA-32 Execution Layer (IA32 EL).

Refer these few links for more details

http://www.redhat.com/docs/manuals/enterprise/RHEL-4-Manual/release-notes/as-itanium/RELEASE-NOTES-U3-ia64-en.html

http://h21007.www2.hp.com/dspp/files/unprotected/32bitto64bit_whitepaper.pdf#search=%2232%20bit%20application%20itanium%22

Re: running 32-bit apps on Itanium

rick jones — Thu, 28 Sep 2006 19:49:48 GMT

"Linux" on Itanium does not provide support for _native_ 32-bit Itanium applications. (HP-UX does). Under Linux the only "32-bit" applications are emulated x86 ones.

That the 32-bit source of several downloaded utilities appears to have compiled and run just fine suggests that they were (at least very close to being) "64-bit clean." If you use the "file" command on the binaries, you will find they are 64-bit. Something along these lines:

[root@tarry ~]# file /opt/netperf2/bin/netperf
/opt/netperf2/bin/netperf: ELF 64-bit LSB executable, IA-64, version 1 (SYSV), for GNU/Linux 2.4.0, dynamically linked (uses shared libs), not stripped

Now, it may still be a good idea to enable greater warning levels just to make sure there are no lurking bugs, but apart from that, simply be happy and enjoy your rx2620!-)