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openxla / xla

A machine learning compiler for GPUs, CPUs, and ML accelerators
Apache License 2.0
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CUDA 12.6 uses PTX ISA version 8.5 not 8.6 #16431

Closed sclarkson closed 2 weeks ago

sclarkson commented 2 weeks ago

While running JAX compiled with CUDA 12.6, I get error messages to the effect of

'+ptx86' is not a recognized feature for this target (ignoring feature)

Per the table here, both CUDA 12.5 and 12.6 use PTX ISA 8.5, making the calculation below no longer correct.

https://github.com/openxla/xla/blob/ce2fffa8197cf8c8fd463b2f849e68746f4678f6/xla/service/gpu/llvm_gpu_backend/gpu_backend_lib.cc#L302-L318

cheshire commented 2 weeks ago

@beckerhe WDYT?

beckerhe commented 2 weeks ago

I never was a fan of the heuristic but I also don't have a good alternative approach.

For now I will cap the PTX version.

sergey-kozub commented 2 weeks ago

Noticed this yesterday, created https://github.com/openxla/xla/pull/16504

sclarkson commented 2 weeks ago

Haven't tested but I'm reasonably sure that fixed it. Thanks.