diff options
Diffstat (limited to 'compiler/GHC/Cmm/Sink.hs')
| -rw-r--r-- | compiler/GHC/Cmm/Sink.hs | 14 |
1 files changed, 12 insertions, 2 deletions
diff --git a/compiler/GHC/Cmm/Sink.hs b/compiler/GHC/Cmm/Sink.hs index cd13d6b655..3ef58b3648 100644 --- a/compiler/GHC/Cmm/Sink.hs +++ b/compiler/GHC/Cmm/Sink.hs @@ -622,10 +622,16 @@ conflicts platform (r, rhs, addr) node -- (5) foreign calls clobber heap: see Note [Foreign calls clobber heap] | CmmUnsafeForeignCall{} <- node, memConflicts addr AnyMem = True - -- (6) native calls clobber any memory + -- (6) suspendThread clobbers every global register not backed by a real + -- register. It also clobbers heap and stack but this is handled by (5) + | CmmUnsafeForeignCall (PrimTarget MO_SuspendThread) _ _ <- node + , foldRegsUsed platform (\b g -> globalRegMaybe platform g == Nothing || b) False rhs + = True + + -- (7) native calls clobber any memory | CmmCall{} <- node, memConflicts addr AnyMem = True - -- (7) otherwise, no conflict + -- (8) otherwise, no conflict | otherwise = False {- Note [Inlining foldRegsDefd] @@ -759,6 +765,10 @@ data AbsMem -- Some CallishMachOp imply a memory barrier e.g. AtomicRMW and -- therefore we should never float any memory operations across one of -- these calls. +-- +-- `suspendThread` releases the capability used by the thread, hence we mustn't +-- float accesses to heap, stack or virtual global registers stored in the +-- capability (e.g. with unregisterised build, see #19237). bothMems :: AbsMem -> AbsMem -> AbsMem |