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To achieve object determinism, the passes processing Cmm and the rest of the code generation pipeline musn't create new uniques which are non-deterministic. This commit changes occurrences of non-deterministic unique sampling within these code generation passes by a deterministic unique sampling strategy by propagating and threading through a deterministic incrementing counter in them. The threading is done implicitly with `UniqDSM` and `UniqDSMT`. Secondly, the `DUniqSupply` used to run a `UniqDSM` must be threaded through all passes to guarantee uniques in different passes are unique amongst them altogether. Specifically, the same `DUniqSupply` must be threaded through the CG Streaming pipeline, starting with Driver.Main calling `StgToCmm.codeGen`, `cmmPipeline`, `cmmToRawCmm`, and `codeOutput` in sequence. To thread resources through the `Stream` abstraction, we use the `UniqDSMT` transformer on top of `IO` as the Monad underlying the Stream. `UniqDSMT` will thread the `DUniqSupply` through every pass applied to the `Stream`, for every element. We use @type CgStream = Stream (UniqDSMT IO)@ for the Stream used in code generation which that carries through the deterministic unique supply. See Note [Deterministic Uniques in the CG]
To achieve object determinism, the passes processing Cmm and the rest of the code generation pipeline musn't create new uniques which are non-deterministic. This commit changes occurrences of non-deterministic unique sampling within these code generation passes by a deterministic unique sampling strategy by propagating and threading through a deterministic incrementing counter in them. The threading is done implicitly with `UniqDSM` and `UniqDSMT`. Secondly, the `DUniqSupply` used to run a `UniqDSM` must be threaded through all passes to guarantee uniques in different passes are unique amongst them altogether. Specifically, the same `DUniqSupply` must be threaded through the CG Streaming pipeline, starting with Driver.Main calling `StgToCmm.codeGen`, `cmmPipeline`, `cmmToRawCmm`, and `codeOutput` in sequence. To thread resources through the `Stream` abstraction, we use the `UniqDSMT` transformer on top of `IO` as the Monad underlying the Stream. `UniqDSMT` will thread the `DUniqSupply` through every pass applied to the `Stream`, for every element. We use @type CgStream = Stream (UniqDSMT IO)@ for the Stream used in code generation which that carries through the deterministic unique supply. See Note [Deterministic Uniques in the CG]
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