[MooreToCore] Lower $time to new LLHD current time op #9378
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maerhart
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Dec 21, 2025
| let hasFolder = 1; | ||
| } | ||
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| def CurrentTimeOp : LLHDOp<"current_time", [Pure]> { |
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It would be illegal to move this operation across an llhd.wait operation, right? E.g., by CSE. So, it shouldn't be marked Pure. Maybe as Read?
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Great catch, thanks! 💯 I've marked this as having a read side-effect instead, and there are new tests to check that unused ops can be DCEd, and that ops only CSE if there is no side-effecting op in between.
Add support for lowering the `moore.builtin.time` op to a new `llhd.current_time` op that simply materializes the current simulation time as an SSA value. Error diff on circt-tests: ```diff -37 error: failed to legalize operation 'moore.builtin.time' +22 error: failed to legalize operation 'moore.time_to_logic' +15 error: failed to legalize operation 'moore.fmt.time' 0 total change ```
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Add support for lowering the
moore.builtin.timeop to a newllhd.current_timeop that simply materializes the current simulation time as an SSA value.Error diff on circt-tests: