problem with l_fc_pc_8.1.024.tar.gz

[anupam_mu]

hello everybody,
i have installed ifort 8.1(l_fc_pc_8.1.024.tar.gz), my programms are is running fine except when i use the -fast option for optimization. when i try to run the file it prints the following error message- "Fatal Error : This program was not built to run on the processor in your system."

i work in hp workstation xw6000 with xeon processor
earlier i was working with ifort 8.0, it didn't show this type of message.

any help is welcome
thank you
anupam

[Steven_L_Intel1]

In version 8.1, -fast also sets -xP, which will cause you this problem if you are not running on one of the Intel processors that support SSE3 instructions. Instead of -fast, use the separate switches: "-O3 -ipo -no-prec-div -static".

[anupam_mu]

thanks sblionel,
latter i found that also from the man page of ifort, but could you be little explicit regarding sse3 instruction. i have no idea about it.
again thanks for ur help.
anupam

[Steven_L_Intel1]

Would it help if I said "Intel processors code named Prescott, Nocona or Smithfield"? I wish I could be more specific, but there is not a simple way to identifty classes of processors that are supported by -xP. Some Xeons qualify, some don't. Some Pentium 4s qualify, some don't. If the Intel processor supports the "Streaming SIMD Extensions 3 (SSE3)" instruction set, then -xP can be used. Otherwise, it can't.

This drove me crazy when I was writing the release notes and helping the documentation writers explain the switches, because, unlike in the past, there was not a single "marketing name" we could give to customers to identify which processors support -xP.