Compiling for newer Intel CPUs with an older Intel build system?

2016-03-04 Thread Sean Byland
Hello, I’m trying to help users get autotools-based projects to compile in our somewhat unique environment. It’s fairly common for users to want to compile on a Intel ivybridge system (node) with Intel broadwell-specific (a superset of CPU instructions) performance optimization to run elsewhere

Re: Compiling for newer Intel CPUs with an older Intel build system?

2016-03-04 Thread Nick Bowler
On 2016-03-04, Sean Byland wrote: > I’m trying to help users get autotools-based projects to compile in our > somewhat unique environment. It’s fairly common for users to want to compile > on a Intel ivybridge system (node) with Intel broadwell-specific (a superset > of CPU instructions) performan

Re: Compiling for newer Intel CPUs with an older Intel build system?

2016-03-04 Thread Mike Frysinger
On 04 Mar 2016 16:11, Sean Byland wrote: > I’m trying to help users get autotools-based projects to compile in our > somewhat unique environment. It’s fairly common for users to want to compile > on a Intel ivybridge system (node) with Intel broadwell-specific (a superset > of CPU instructions)

Re: Compiling for newer Intel CPUs with an older Intel build system?

2016-03-04 Thread Nick Bowler
On 2016-03-04, Sean Byland wrote: > On 3/4/16, 12:24 PM, "Nick Bowler" wrote: >>On 2016-03-04, Sean Byland wrote: [...] >>> 2. Generating a config.cache on the Ivybridge compute node, which >>> shares the majority of the file system with the Sandybridge system >>> and can successfully execute ev

Re: Compiling for newer Intel CPUs with an older Intel build system?

2016-03-04 Thread Mike Frysinger
On 04 Mar 2016 19:16, Sean Byland wrote: > Thanks. Targeting the least common denominator ISA to get portable code > works well for many things but in this case I’m curious about getting > better performance than portability. that's not what you said. you said you wanted to build on a newer cpu a

Re: Compiling for newer Intel CPUs with an older Intel build system?

2016-03-04 Thread Sean Byland
On 3/4/16, 12:24 PM, "Nick Bowler" wrote: >On 2016-03-04, Sean Byland wrote: >> I’m trying to help users get autotools-based projects to compile in our >> somewhat unique environment. It’s fairly common for users to want to >>compile >> on a Intel ivybridge system (node) with Intel broadwell-s

Re: Compiling for newer Intel CPUs with an older Intel build system?

2016-03-04 Thread Sean Byland
Thanks. Targeting the least common denominator ISA to get portable code works well for many things but in this case I’m curious about getting better performance than portability. Sean On 3/4/16, 12:41 PM, "Mike Frysinger" wrote: >On 04 Mar 2016 16:11, Sean Byland wrote: >> I’m trying to help us

Re: Compiling for newer Intel CPUs with an older Intel build system?

2016-03-04 Thread Bob Friesenhahn
On Fri, 4 Mar 2016, Nick Bowler wrote: This sounds like a nice idea in concept, but unfortunately the config.cache files are not meant to be shared between different packages. This has been tried before, and it inevitably leads to disaster. Most obvious is the possibility of namespace collisio