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Geza Lore
d1eda66668
The only use for the clocker attribute and the AstVar::isUsedClock that is actually necessary today for correctness is to mark top level inputs of --lib-create blocks as being (or driving) a clock signal. Correctness of --lib-create (and hence hierarchical blocks) actually used to depend on having the right optimizations eliminate intermediate clocks (e.g.: V3Gate), when the top level port was not used directly in a sensitivity list, or marking top level signals manually via --clk or the clocker attribute. However V3Sched::partition already needs to trace through the logic to figure out what signals might drive a sensitivity list, so it can very easily mark all top level inputs as such. In this patch we remove the AstVar::attrClocker and AstVar::isUsedClock attributes, and replace them with AstVar::isPrimaryClock, automatically set by V3Sched::partition. This eliminates all need for manual annotation so we are deprecating the --clk/--no-clk options and the clocker/no_clocker attributes. This also eliminates the opportunity for any further mis-optimization similar to #6453. Regarding the other uses of the removed AstVar attributes: - As of 5.000, initial edges are triggered via a separate mechanism applied in V3Sched, so the use in V3EmitCFunc.cpp is redundant - Also as of 5.000, we can handle arbitrary sensitivity expressions, so the restriction on eliminating clock signals in V3Gate is unnecessary - Since the recent change when Dfg is applied after V3Scope, it does perform the equivalent of GateClkDecomp, so we can delete that pass.