[FIRRTL] Constant will be elimated on the DPI Path

llvm / circt

Circuit IR Compilers and Tools

https://circt.org

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[FIRRTL] Constant will be elimated on the DPI Path #7228

Open sequencer opened 6 days ago

sequencer commented 6 days ago

I'm not sure if this is a bug. If a constant e.g. channelId propagating to DPI function, it will be eliminated. I'm currently using a dontTouch to work around, but I think this should be resolved in CIRCT.

dtzSiFive commented 2 days ago

Can you provide an example or maybe elaborate a bit?

What does it mean that they are eliminated? They're fed to DPI calls but the inputs to the DPI function are dropped (?) if the input is a constant, ...?