masahi commented on issue #8296: URL: https://github.com/apache/tvm/issues/8296#issuecomment-904568003
It looks like transformer like models have many `softmax` ops that introduce a lot of casting before / after them, like https://gist.github.com/masahi/0d7d96ae88722b616a906cec2054559e#file-transformer-txt-L137-L143 The fact that softmax and the following cast to fp16 are not fused surprised me. This is because the op pattern for softmax is kOpaque, https://github.com/apache/tvm/blob/66ac4705aae9bec92047920c8a9273693cd48c44/python/tvm/relay/op/nn/_nn.py#L42. The cast overheads are big if they are not fused, so we are leaving a lot of perf on the table. @yzhliu Is there a reason softmax op pattern cannot be `OUT_ELEMWISE_FUSABLE`? -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: [email protected] For queries about this service, please contact Infrastructure at: [email protected]
