From bd973526bbbdd6e529d429eceff32655ad671280 Mon Sep 17 00:00:00 2001 From: Ben Gamari Date: Tue, 30 Aug 2016 21:08:05 -0400 Subject: [PATCH] StgCmmPrim: Add missing MO_WriteBarrier StgCmmPrim: Add missing MO_WriteBarrier Test Plan: Good question Reviewers: austin, trommler, simonmar, rrnewton Reviewed By: simonmar Subscribers: RyanGlScott, thomie Differential Revision: https://phabricator.haskell.org/D2495 GHC Trac Issues: #12469 (cherry picked from commit d40d6df74a9fca382a84709ac9bc862897fbec18) Gbp-Pq: Name add-missing-MO_WriteBarrier --- compiler/codeGen/StgCmmPrim.hs | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) diff --git a/compiler/codeGen/StgCmmPrim.hs b/compiler/codeGen/StgCmmPrim.hs index 5d3b94f0..3cb9f83c 100644 --- a/compiler/codeGen/StgCmmPrim.hs +++ b/compiler/codeGen/StgCmmPrim.hs @@ -310,8 +310,11 @@ emitPrimOp _ [res] GetCurrentCCSOp [_dummy_arg] emitPrimOp dflags [res] ReadMutVarOp [mutv] = emitAssign (CmmLocal res) (cmmLoadIndexW dflags mutv (fixedHdrSizeW dflags) (gcWord dflags)) -emitPrimOp dflags [] WriteMutVarOp [mutv,var] - = do emitStore (cmmOffsetW dflags mutv (fixedHdrSizeW dflags)) var +emitPrimOp dflags res@[] WriteMutVarOp [mutv,var] + = do -- Without this write barrier, other CPUs may see this pointer before + -- the writes for the closure it points to have occurred. + emitPrimCall res MO_WriteBarrier [] + emitStore (cmmOffsetW dflags mutv (fixedHdrSizeW dflags)) var emitCCall [{-no results-}] (CmmLit (CmmLabel mkDirty_MUT_VAR_Label)) -- 2.30.2