-- complain to Norman Ramsey.
module MkZipCfgCmm
- ( mkNop, mkAssign, mkStore, mkCall, mkUnsafeCall, mkFinalCall
- , mkJump, mkCbranch, mkSwitch, mkReturn, mkComment, mkCmmIfThenElse
- , mkCmmWhileDo
- , (<*>), mkLabel, mkBranch
+ ( mkNop, mkAssign, mkStore, mkCall, mkCmmCall, mkSafeCall, mkUnsafeCall, mkFinalCall
+ , mkJump, mkForeignJump, mkJumpGC, mkCbranch, mkSwitch, mkReturn
+ , mkReturnSimple, mkComment, copyInOflow, copyInSlot, copyOutOflow, copyOutSlot
+ , mkEntry, mkCmmIfThenElse, mkCmmIfThen, mkCmmWhileDo
+ , (<*>), catAGraphs, mkLabel, mkBranch
, emptyAGraph, withFreshLabel, withUnique, outOfLine
, lgraphOfAGraph, graphOfAGraph, labelAGraph
- , CmmZ, CmmTopZ, CmmGraph, CmmBlock, CmmAGraph, Middle, Last, Convention(..)
+ , CmmZ, CmmTopZ, CmmGraph, CmmBlock, CmmAGraph, CmmStackInfo
+ , Middle, Last, Convention(..), ForeignConvention(..), MidCallTarget(..), Transfer(..)
+ , stackStubExpr, pprAGraph
)
where
#include "HsVersions.h"
+import BlockId
import CmmExpr
import Cmm ( GenCmm(..), GenCmmTop(..), CmmStatic, CmmInfo
- , CmmCallTarget(..), CmmActuals, CmmFormals
+ , CmmActuals, CmmFormals
)
+import CmmCallConv (assignArgumentsPos, ParamLocation(..))
import ZipCfgCmmRep hiding (CmmGraph, CmmAGraph, CmmBlock, CmmZ, CmmTopZ)
- -- ^ to make this module more self-contained, these definitions are duplicated below
+ -- to make this module more self-contained, the above definitions are
+ -- duplicated below
import PprCmm()
-import ClosureInfo
import FastString
import ForeignCall
-import ZipCfg
import MkZipCfg
+import Panic
+import SMRep (ByteOff)
+import StaticFlags
+import ZipCfg
type CmmGraph = LGraph Middle Last
type CmmAGraph = AGraph Middle Last
type CmmBlock = Block Middle Last
-type CmmZ = GenCmm CmmStatic CmmInfo CmmGraph
-type CmmTopZ = GenCmmTop CmmStatic CmmInfo CmmGraph
+type CmmStackInfo = (ByteOff, Maybe ByteOff)
+ -- probably want a record; (SP offset on entry, update frame space)
+type CmmZ = GenCmm CmmStatic CmmInfo (CmmStackInfo, CmmGraph)
+type CmmTopZ = GenCmmTop CmmStatic CmmInfo (CmmStackInfo, CmmGraph)
+data Transfer = Call | Jump | Ret deriving Eq
+
+---------- No-ops
mkNop :: CmmAGraph
+mkComment :: FastString -> CmmAGraph
+
+---------- Assignment and store
mkAssign :: CmmReg -> CmmExpr -> CmmAGraph
mkStore :: CmmExpr -> CmmExpr -> CmmAGraph
-mkCall :: CmmExpr -> CCallConv -> CmmFormals -> CmmActuals -> C_SRT -> CmmAGraph
-mkUnsafeCall :: CmmCallTarget -> CmmFormals -> CmmActuals -> CmmAGraph
-mkFinalCall :: CmmExpr -> CCallConv -> CmmActuals -> CmmAGraph
- -- Never returns; like exit() or barf()
-mkJump :: CmmExpr -> CmmActuals -> CmmAGraph
-mkCbranch :: CmmExpr -> BlockId -> BlockId -> CmmAGraph
-mkSwitch :: CmmExpr -> [Maybe BlockId] -> CmmAGraph
-mkReturn :: CmmActuals -> CmmAGraph
-mkComment :: FastString -> CmmAGraph
--- Not to be forgotten, but exported by MkZipCfg:
---mkBranch :: BlockId -> CmmAGraph
---mkLabel :: BlockId -> CmmAGraph
+---------- Calls
+mkCall :: CmmExpr -> (Convention, Convention) -> CmmFormals -> CmmActuals ->
+ UpdFrameOffset -> CmmAGraph
+mkCmmCall :: CmmExpr -> CmmFormals -> CmmActuals ->
+ UpdFrameOffset -> CmmAGraph
+ -- Native C-- calling convention
+mkSafeCall :: MidCallTarget -> CmmFormals -> CmmActuals -> UpdFrameOffset -> CmmAGraph
+mkUnsafeCall :: MidCallTarget -> CmmFormals -> CmmActuals -> CmmAGraph
+mkFinalCall :: CmmExpr -> CCallConv -> CmmActuals -> UpdFrameOffset -> CmmAGraph
+ -- Never returns; like exit() or barf()
+
+---------- Control transfer
+mkJump :: CmmExpr -> CmmActuals -> UpdFrameOffset -> CmmAGraph
+mkJumpGC :: CmmExpr -> CmmActuals -> UpdFrameOffset -> CmmAGraph
+mkForeignJump :: Convention -> CmmExpr -> CmmActuals -> UpdFrameOffset -> CmmAGraph
+mkCbranch :: CmmExpr -> BlockId -> BlockId -> CmmAGraph
+mkSwitch :: CmmExpr -> [Maybe BlockId] -> CmmAGraph
+mkReturn :: CmmExpr -> CmmActuals -> UpdFrameOffset -> CmmAGraph
+mkReturnSimple :: CmmActuals -> UpdFrameOffset -> CmmAGraph
+
mkCmmIfThenElse :: CmmExpr -> CmmAGraph -> CmmAGraph -> CmmAGraph
-mkCmmWhileDo :: CmmExpr -> CmmAGraph -> CmmAGraph
+mkCmmIfThen :: CmmExpr -> CmmAGraph -> CmmAGraph
+mkCmmWhileDo :: CmmExpr -> CmmAGraph -> CmmAGraph
+
+-- Not to be forgotten, but exported by MkZipCfg:
+-- mkBranch :: BlockId -> CmmAGraph
+-- mkLabel :: BlockId -> Maybe Int -> CmmAGraph
+-- outOfLine :: CmmAGraph -> CmmAGraph
+-- withUnique :: (Unique -> CmmAGraph) -> CmmAGraph
+-- withFreshLabel :: String -> (BlockId -> CmmAGraph) -> CmmAGraph
--------------------------------------------------------------------------
+mkCmmWhileDo e = mkWhileDo (mkCbranch e)
mkCmmIfThenElse e = mkIfThenElse (mkCbranch e)
-mkCmmWhileDo e = mkWhileDo (mkCbranch e)
+
+mkCmmIfThen e tbranch
+ = withFreshLabel "end of if" $ \endif ->
+ withFreshLabel "start of then" $ \tid ->
+ mkCbranch e tid endif <*>
+ mkLabel tid <*> tbranch <*> mkBranch endif <*>
+ mkLabel endif
+
-- ================ IMPLEMENTATION ================--
-mkNop = mkMiddle $ MidNop
+mkNop = emptyAGraph
mkComment fs = mkMiddle $ MidComment fs
-mkAssign l r = mkMiddle $ MidAssign l r
mkStore l r = mkMiddle $ MidStore l r
-mkCbranch pred ifso ifnot = mkLast $ LastCondBranch pred ifso ifnot
-mkSwitch e tbl = mkLast $ LastSwitch e tbl
+-- NEED A COMPILER-DEBUGGING FLAG HERE
+-- Sanity check: any value assigned to a pointer must be non-zero.
+-- If it's 0, cause a crash immediately.
+mkAssign l r = if opt_StubDeadValues then assign l r <*> check l else assign l r
+ where assign l r = mkMiddle (MidAssign l r)
+ check (CmmGlobal _) = mkNop
+ check l@(CmmLocal reg) = -- if a ptr arg is NULL, cause a crash!
+ if isGcPtrType ty then
+ mkCmmIfThen (CmmMachOp (MO_Eq w) [r, stackStubExpr w])
+ (assign l (CmmLoad (CmmLit (CmmInt 0 w)) ty))
+ else mkNop
+ where ty = localRegType reg
+ w = typeWidth ty
+ r = CmmReg l
+
+
+-- Why are we inserting extra blocks that simply branch to the successors?
+-- Because in addition to the branch instruction, @mkBranch@ will insert
+-- a necessary adjustment to the stack pointer.
+mkCbranch pred ifso ifnot = mkLast (LastCondBranch pred ifso ifnot)
+mkSwitch e tbl = mkLast $ LastSwitch e tbl
+
+mkSafeCall t fs as upd =
+ withFreshLabel "safe call" $ \k ->
+ mkMiddle $ MidForeignCall (Safe k upd) t fs as
+mkUnsafeCall t fs as = mkMiddle $ MidForeignCall Unsafe t fs as
+
+-- For debugging purposes, we can stub out dead stack slots:
+stackStubExpr :: Width -> CmmExpr
+stackStubExpr w = CmmLit (CmmInt 0 w)
+
+-- When we copy in parameters, we usually want to put overflow
+-- parameters on the stack, but sometimes we want to pass
+-- the variables in their spill slots.
+-- Therefore, for copying arguments and results, we provide different
+-- functions to pass the arguments in an overflow area and to pass them in spill slots.
+copyInOflow :: Convention -> Area -> CmmFormals -> (Int, CmmAGraph)
+copyInSlot :: Convention -> CmmFormals -> CmmAGraph
+copyOutOflow :: Convention -> Transfer -> Area -> CmmActuals -> UpdFrameOffset ->
+ (Int, [Middle])
+copyOutSlot :: Convention -> [LocalReg] -> [Middle]
+ -- why a list of middles here instead of an AGraph?
+
+copyInOflow = copyIn oneCopyOflowI
+copyInSlot c f = snd $ copyIn oneCopySlotI c (panic "no area for copying to slots") f
+
+type SlotCopier = Area -> (LocalReg, ByteOff) -> (ByteOff, CmmAGraph) ->
+ (ByteOff, CmmAGraph)
+type CopyIn = SlotCopier -> Convention -> Area -> CmmFormals -> (ByteOff, CmmAGraph)
+
+-- Return the number of bytes used for copying arguments, as well as the
+-- instructions to copy the arguments.
+copyIn :: CopyIn
+copyIn oflow conv area formals =
+ foldr ci (init_offset, mkNop) args'
+ where ci (reg, RegisterParam r) (n, ms) =
+ (n, mkAssign (CmmLocal reg) (CmmReg $ CmmGlobal r) <*> ms)
+ ci (r, StackParam off) (n, ms) = oflow area (r, off) (n, ms)
+ init_offset = widthInBytes wordWidth -- infotable
+ args = assignArgumentsPos conv localRegType formals
+ args' = foldl adjust [] args
+ where adjust rst (v, StackParam off) = (v, StackParam (off + init_offset)) : rst
+ adjust rst x@(_, RegisterParam _) = x : rst
+
+-- Copy-in one arg, using overflow space if needed.
+oneCopyOflowI, oneCopySlotI :: SlotCopier
+oneCopyOflowI area (reg, off) (n, ms) =
+ (max n off, mkAssign (CmmLocal reg) (CmmLoad (CmmStackSlot area off) ty) <*> ms)
+ where ty = localRegType reg
+
+-- Copy-in one arg, using spill slots if needed -- used for calling conventions at
+-- a procpoint that is not a return point. The offset is irrelevant here...
+oneCopySlotI _ (reg, _) (n, ms) =
+ (n, mkAssign (CmmLocal reg) (CmmLoad (CmmStackSlot (RegSlot reg) w) ty) <*> ms)
+ where ty = localRegType reg
+ w = widthInBytes (typeWidth ty)
+
+
+-- Factoring out the common parts of the copyout functions yielded something
+-- more complicated:
+
+-- The argument layout function ignores the pointer to the info table, so we slot that
+-- in here. When copying-out to a young area, we set the info table for return
+-- and adjust the offsets of the other parameters.
+-- If this is a call instruction, we adjust the offsets of the other parameters.
+copyOutOflow conv transfer area@(CallArea a) actuals updfr_off =
+ foldr co (init_offset, []) args'
+ where co (v, RegisterParam r) (n, ms) = (n, MidAssign (CmmGlobal r) v : ms)
+ co (v, StackParam off) (n, ms) =
+ (max n off, MidStore (CmmStackSlot area off) v : ms)
+ (setRA, init_offset) =
+ case a of Young id@(BlockId _) -> -- set RA if making a call
+ if transfer == Call then
+ ([(CmmLit (CmmBlock id), StackParam init_offset)],
+ widthInBytes wordWidth)
+ else ([], 0)
+ Old -> ([], updfr_off)
+ args = assignArgumentsPos conv cmmExprType actuals
+ args' = foldl adjust setRA args
+ where adjust rst (v, StackParam off) = (v, StackParam (off + init_offset)) : rst
+ adjust rst x@(_, RegisterParam _) = x : rst
+copyOutOflow _ _ (RegSlot _) _ _ = panic "cannot copy arguments into a register slot"
+
+-- Args passed only in registers and stack slots; no overflow space.
+-- No return address may apply!
+copyOutSlot conv actuals = foldr co [] args
+ where co (v, RegisterParam r) ms = MidAssign (CmmGlobal r) (toExp v) : ms
+ co (v, StackParam off) ms =
+ MidStore (CmmStackSlot (RegSlot v) off) (toExp v) : ms
+ toExp r = CmmReg (CmmLocal r)
+ args = assignArgumentsPos conv localRegType actuals
+
+-- oneCopySlotO _ (reg, _) (n, ms) =
+-- (n, MidStore (CmmStackSlot (RegSlot reg) w) reg : ms)
+-- where w = widthInBytes (typeWidth (localRegType reg))
+
+mkEntry :: BlockId -> Convention -> CmmFormals -> (Int, CmmAGraph)
+mkEntry _ conv formals = copyInOflow conv (CallArea Old) formals
-mkUnsafeCall tgt results actuals = mkMiddle $ MidUnsafeCall tgt results actuals
+lastWithArgs :: Transfer -> Area -> Convention -> CmmActuals -> UpdFrameOffset ->
+ (ByteOff -> Last) -> CmmAGraph
+lastWithArgs transfer area conv actuals updfr_off last =
+ let (outArgs, copies) = copyOutOflow conv transfer area actuals updfr_off in
+ mkMiddles copies <*> mkLast (last outArgs)
-cmmArgConv, cmmResConv :: Convention
-cmmArgConv = ConventionStandard CmmCallConv Arguments
-cmmResConv = ConventionStandard CmmCallConv Arguments
+-- The area created for the jump and return arguments is the same area as the
+-- procedure entry.
+old :: Area
+old = CallArea Old
+toCall :: CmmExpr -> Maybe BlockId -> UpdFrameOffset -> ByteOff -> ByteOff -> Last
+toCall e cont updfr_off res_space arg_space =
+ LastCall e cont arg_space res_space (Just updfr_off)
+mkJump e actuals updfr_off =
+ lastWithArgs Jump old NativeNodeCall actuals updfr_off $ toCall e Nothing updfr_off 0
+mkJumpGC e actuals updfr_off =
+ lastWithArgs Jump old GC actuals updfr_off $ toCall e Nothing updfr_off 0
+mkForeignJump conv e actuals updfr_off =
+ lastWithArgs Jump old conv actuals updfr_off $ toCall e Nothing updfr_off 0
+mkReturn e actuals updfr_off =
+ lastWithArgs Ret old NativeReturn actuals updfr_off $ toCall e Nothing updfr_off 0
+ -- where e = CmmLoad (CmmStackSlot (CallArea Old) updfr_off) gcWord
+mkReturnSimple actuals updfr_off =
+ lastWithArgs Ret old NativeReturn actuals updfr_off $ toCall e Nothing updfr_off 0
+ where e = CmmLoad (CmmStackSlot (CallArea Old) updfr_off) gcWord
-mkJump e actuals = mkMiddle (CopyOut cmmArgConv actuals) <*> mkLast (LastJump e)
-mkReturn actuals = mkMiddle (CopyOut cmmResConv actuals) <*> mkLast LastReturn
+mkFinalCall f _ actuals updfr_off =
+ lastWithArgs Call old NativeDirectCall actuals updfr_off $ toCall f Nothing updfr_off 0
-mkFinalCall f conv actuals =
- mkMiddle (CopyOut (ConventionStandard conv Arguments) actuals) <*>
- mkLast (LastCall f Nothing)
+mkCmmCall f results actuals = mkCall f (NativeDirectCall, NativeReturn) results actuals
-mkCall f conv results actuals srt =
- withFreshLabel "call successor" $ \k ->
- mkMiddle (CopyOut (ConventionStandard conv Arguments) actuals) <*>
- mkLast (LastCall f (Just k)) <*>
- mkLabel k <*>
- mkMiddle (CopyIn (ConventionStandard conv Results) results srt)
+-- I'm dropping the SRT, but that should be okay: we plan to reconstruct it later.
+mkCall f (callConv, retConv) results actuals updfr_off =
+ withFreshLabel "call successor" $ \k ->
+ let area = CallArea $ Young k
+ (off, copyin) = copyInOflow retConv area results
+ copyout = lastWithArgs Call area callConv actuals updfr_off
+ (toCall f (Just k) updfr_off off)
+ in (copyout <*> mkLabel k <*> copyin)