diff options
Diffstat (limited to 'compiler/codeGen/CgStackery.lhs')
| -rw-r--r-- | compiler/codeGen/CgStackery.lhs | 28 |
1 files changed, 23 insertions, 5 deletions
diff --git a/compiler/codeGen/CgStackery.lhs b/compiler/codeGen/CgStackery.lhs index 6683de4c8b..532127a147 100644 --- a/compiler/codeGen/CgStackery.lhs +++ b/compiler/codeGen/CgStackery.lhs @@ -17,7 +17,7 @@ module CgStackery ( setStackFrame, getStackFrame, mkVirtStkOffsets, mkStkAmodes, freeStackSlots, - pushUpdateFrame, emitPushUpdateFrame, + pushUpdateFrame, pushBHUpdateFrame, emitPushUpdateFrame, ) where #include "HsVersions.h" @@ -265,6 +265,14 @@ to reflect the frame pushed. \begin{code} pushUpdateFrame :: CmmExpr -> Code -> Code pushUpdateFrame updatee code + = pushSpecUpdateFrame mkUpdInfoLabel updatee code + +pushBHUpdateFrame :: CmmExpr -> Code -> Code +pushBHUpdateFrame updatee code + = pushSpecUpdateFrame mkBHUpdInfoLabel updatee code + +pushSpecUpdateFrame :: CLabel -> CmmExpr -> Code -> Code +pushSpecUpdateFrame lbl updatee code = do { when debugIsOn $ do { EndOfBlockInfo _ sequel <- getEndOfBlockInfo ; @@ -277,15 +285,25 @@ pushUpdateFrame updatee code -- The location of the lowest-address -- word of the update frame itself - ; setEndOfBlockInfo (EndOfBlockInfo vsp UpdateCode) $ - do { emitPushUpdateFrame frame_addr updatee + -- NB. we used to set the Sequel to 'UpdateCode' so + -- that we could jump directly to the update code if + -- we know that the next frame on the stack is an + -- update frame. However, the RTS can sometimes + -- change an update frame into something else (see + -- e.g. Note [upd-black-hole] in rts/sm/Scav.c), so we + -- no longer make this assumption. + ; setEndOfBlockInfo (EndOfBlockInfo vsp OnStack) $ + do { emitSpecPushUpdateFrame lbl frame_addr updatee ; code } } emitPushUpdateFrame :: CmmExpr -> CmmExpr -> Code -emitPushUpdateFrame frame_addr updatee = do +emitPushUpdateFrame = emitSpecPushUpdateFrame mkUpdInfoLabel + +emitSpecPushUpdateFrame :: CLabel -> CmmExpr -> CmmExpr -> Code +emitSpecPushUpdateFrame lbl frame_addr updatee = do stmtsC [ -- Set the info word - CmmStore frame_addr (mkLblExpr mkUpdInfoLabel) + CmmStore frame_addr (mkLblExpr lbl) , -- And the updatee CmmStore (cmmOffsetB frame_addr off_updatee) updatee ] initUpdFrameProf frame_addr |