- vectorisation
- = runWhen (dopt Opt_Vectorise dflags)
- $ CoreDoPasses [ simpl_gently, CoreDoVectorisation (dphPackage dflags) ]
+ -- Vectorisation can introduce a fair few common sub expressions involving
+ -- DPH primitives. For example, see the Reverse test from dph-examples.
+ -- We need to eliminate these common sub expressions before their definitions
+ -- are inlined in phase 2. The CSE introduces lots of v1 = v2 bindings,
+ -- so we also run simpl_gently to inline them.
+ ++ (if dopt Opt_Vectorise dflags && phase == 3
+ then [CoreCSE, simpl_gently]
+ else [])