Building on an older x86

[MoonbaseOtago]

I'm building a server for a bunch of things including on an older x86 CPU (march=x86_64-v2) . Mostly it's because lots of DDR3 is cheap(er) these days

On it I've built openroad locally (there's a kepler issue with MMX that I've fixed, it builds and runs - mostly. When I make a flow it compiles/places/routes and crashes at the very very end- when I try "openroad -gui" it crashes too

I've chased it down to it being statically linked to an x86_64-v3 (or later) qt library - it does executing an andn instruction (not ava;lable in x86_64-v2).

So my question is where do the qt libraries come from? Ubuntu seems to have got the local qt libraries correct, just forcing a link locally rather than doing a static link will fix it

Anyone understand what bazel is doing with qt here, where the knobs are so I can tweak it ?

[maliberty]

@QuantamHD setup https://github.com/The-OpenROAD-Project/qt_bazel_prebuilts to get a uniform version across platforms. You might just try using the web interface that is qt-free.

[QuantamHD]

Since by default we cache artifacts on a reasonably modern system you might be picking up cached versions that are beyond your systems capability. I would pass the following to eliminate the cache bazelisk build -c opt --copt="-march=native" //:openroad. I'm assuming you are building openroad on the DDR3 server and that march=native will pick up your particular servers capability.

[MoonbaseOtago]

Yes, I'm building it there, I was trying to do essentially that via a .bazelrc file (but blew away my cache ...) I'm actually building from the OpenRoad Flow Scripts repo so I get whatever they use for invoking bazel

[QuantamHD]

I'm a bit less familiar with how it gets built in ORFS. @maliberty any guidance there on how to add this flag?

Could you try building the repo directly with the flag I mentioned to see if we can disentangle the compilation issues from the scripting issues in ORFS?

[MoonbaseOtago]

I will play a bit once the bazel repo issue gets resolved

[MoonbaseOtago]

I'm going to start a new thread on the build problem

[MoonbaseOtago]

OK - figured out what's happening - the qt_bazel_prebuilts are the problem - someone ran "./configure" on an x86_64-V3 system and checked in the results (so it builds for AVX2 systems)

In a couple of days (I'm at a con) I'll build a fork of that repo with .configure run on an x86_64-V2 - people who need a system can choose this one, or OR people can choose to merge it back with the original, I'll post the information to do it here