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Ticket #9696 reported that `readRawBufferPtr` and `writeRawBufferPtr` allocated unnecessarily. The binding is question was, ``` let { buf_s4VD [Dmd=<L,U(U)>] :: GHC.Ptr.Ptr GHC.Word.Word8 [LclId, Unf=OtherCon []] = NO_CCS GHC.Ptr.Ptr! [ds1_s4Vy]; } in case GHC.IO.FD.$wreadRawBufferPtr Main.main5 0# 0# buf_s4VD Main.main4 Main.main3 GHC.Prim.void# of ... ``` The problem was that GHC apparently couldn't tell that `readRawBufferPtr` would always demand the buffer. Here we simple add bang patterns on all of the small arguments of these functions to ensure that worker/wrappers can eliminate these allocations. Test Plan: Look at STG produced by testcase in #9696, verify no allocations Reviewers: austin, hvr, simonmar Reviewed By: simonmar Subscribers: RyanGlScott, simonmar, thomie Differential Revision: https://phabricator.haskell.org/D2813 GHC Trac Issues: #9696
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