1 {-# OPTIONS -Wall -fno-warn-name-shadowing #-}
3 -- This is the module to import to be able to build C-- programs.
4 -- It should not be necessary to import MkZipCfg or ZipCfgCmmRep.
5 -- If you find it necessary to import these other modules, please
6 -- complain to Norman Ramsey.
9 ( mkNop, mkAssign, mkStore, mkCall, mkCmmCall, mkSafeCall, mkUnsafeCall, mkFinalCall
10 , mkJump, mkForeignJump, mkJumpGC, mkCbranch, mkSwitch, mkReturn
11 , mkReturnSimple, mkComment, copyInOflow, copyInSlot, copyOutOflow, copyOutSlot
12 , mkEntry, mkCmmIfThenElse, mkCmmIfThen, mkCmmWhileDo
13 , (<*>), catAGraphs, mkLabel, mkBranch
14 , emptyAGraph, withFreshLabel, withUnique, outOfLine
15 , lgraphOfAGraph, graphOfAGraph, labelAGraph
16 , CmmZ, CmmTopZ, CmmGraph, CmmBlock, CmmAGraph, CmmStackInfo
17 , Middle, Last, Convention(..), ForeignConvention(..), MidCallTarget(..), Transfer(..)
18 , stackStubExpr, pprAGraph
22 #include "HsVersions.h"
26 import Cmm ( GenCmm(..), GenCmmTop(..), CmmStatic, CmmInfo
27 , CmmActuals, CmmFormals
29 import CmmCallConv (assignArgumentsPos, ParamLocation(..))
30 import ZipCfgCmmRep hiding (CmmGraph, CmmAGraph, CmmBlock, CmmZ, CmmTopZ)
31 -- to make this module more self-contained, the above definitions are
39 import SMRep (ByteOff)
43 type CmmGraph = LGraph Middle Last
44 type CmmAGraph = AGraph Middle Last
45 type CmmBlock = Block Middle Last
46 type CmmStackInfo = (ByteOff, Maybe ByteOff)
47 -- probably want a record; (SP offset on entry, update frame space)
48 type CmmZ = GenCmm CmmStatic CmmInfo (CmmStackInfo, CmmGraph)
49 type CmmTopZ = GenCmmTop CmmStatic CmmInfo (CmmStackInfo, CmmGraph)
51 data Transfer = Call | Jump | Ret deriving Eq
55 mkComment :: FastString -> CmmAGraph
57 ---------- Assignment and store
58 mkAssign :: CmmReg -> CmmExpr -> CmmAGraph
59 mkStore :: CmmExpr -> CmmExpr -> CmmAGraph
62 mkCall :: CmmExpr -> (Convention, Convention) -> CmmFormals -> CmmActuals ->
63 UpdFrameOffset -> CmmAGraph
64 mkCmmCall :: CmmExpr -> CmmFormals -> CmmActuals ->
65 UpdFrameOffset -> CmmAGraph
66 -- Native C-- calling convention
67 mkSafeCall :: MidCallTarget -> CmmFormals -> CmmActuals -> UpdFrameOffset -> CmmAGraph
68 mkUnsafeCall :: MidCallTarget -> CmmFormals -> CmmActuals -> CmmAGraph
69 mkFinalCall :: CmmExpr -> CCallConv -> CmmActuals -> UpdFrameOffset -> CmmAGraph
70 -- Never returns; like exit() or barf()
72 ---------- Control transfer
73 mkJump :: CmmExpr -> CmmActuals -> UpdFrameOffset -> CmmAGraph
74 mkJumpGC :: CmmExpr -> CmmActuals -> UpdFrameOffset -> CmmAGraph
75 mkForeignJump :: Convention -> CmmExpr -> CmmActuals -> UpdFrameOffset -> CmmAGraph
76 mkCbranch :: CmmExpr -> BlockId -> BlockId -> CmmAGraph
77 mkSwitch :: CmmExpr -> [Maybe BlockId] -> CmmAGraph
78 mkReturn :: CmmExpr -> CmmActuals -> UpdFrameOffset -> CmmAGraph
79 mkReturnSimple :: CmmActuals -> UpdFrameOffset -> CmmAGraph
81 mkCmmIfThenElse :: CmmExpr -> CmmAGraph -> CmmAGraph -> CmmAGraph
82 mkCmmIfThen :: CmmExpr -> CmmAGraph -> CmmAGraph
83 mkCmmWhileDo :: CmmExpr -> CmmAGraph -> CmmAGraph
85 -- Not to be forgotten, but exported by MkZipCfg:
86 -- mkBranch :: BlockId -> CmmAGraph
87 -- mkLabel :: BlockId -> Maybe Int -> CmmAGraph
88 -- outOfLine :: CmmAGraph -> CmmAGraph
89 -- withUnique :: (Unique -> CmmAGraph) -> CmmAGraph
90 -- withFreshLabel :: String -> (BlockId -> CmmAGraph) -> CmmAGraph
92 --------------------------------------------------------------------------
94 mkCmmWhileDo e = mkWhileDo (mkCbranch e)
95 mkCmmIfThenElse e = mkIfThenElse (mkCbranch e)
98 = withFreshLabel "end of if" $ \endif ->
99 withFreshLabel "start of then" $ \tid ->
100 mkCbranch e tid endif <*>
101 mkLabel tid <*> tbranch <*> mkBranch endif <*>
106 -- ================ IMPLEMENTATION ================--
109 mkComment fs = mkMiddle $ MidComment fs
110 mkStore l r = mkMiddle $ MidStore l r
112 -- NEED A COMPILER-DEBUGGING FLAG HERE
113 -- Sanity check: any value assigned to a pointer must be non-zero.
114 -- If it's 0, cause a crash immediately.
115 mkAssign l r = if opt_StubDeadValues then assign l r <*> check l else assign l r
116 where assign l r = mkMiddle (MidAssign l r)
117 check (CmmGlobal _) = mkNop
118 check l@(CmmLocal reg) = -- if a ptr arg is NULL, cause a crash!
119 if isGcPtrType ty then
120 mkCmmIfThen (CmmMachOp (MO_Eq w) [r, stackStubExpr w])
121 (assign l (CmmLoad (CmmLit (CmmInt 0 w)) ty))
123 where ty = localRegType reg
128 -- Why are we inserting extra blocks that simply branch to the successors?
129 -- Because in addition to the branch instruction, @mkBranch@ will insert
130 -- a necessary adjustment to the stack pointer.
131 mkCbranch pred ifso ifnot = mkLast (LastCondBranch pred ifso ifnot)
132 mkSwitch e tbl = mkLast $ LastSwitch e tbl
134 mkSafeCall t fs as upd =
135 withFreshLabel "safe call" $ \k ->
136 mkMiddle $ MidForeignCall (Safe k upd) t fs as
137 mkUnsafeCall t fs as = mkMiddle $ MidForeignCall Unsafe t fs as
139 -- For debugging purposes, we can stub out dead stack slots:
140 stackStubExpr :: Width -> CmmExpr
141 stackStubExpr w = CmmLit (CmmInt 0 w)
143 -- When we copy in parameters, we usually want to put overflow
144 -- parameters on the stack, but sometimes we want to pass
145 -- the variables in their spill slots.
146 -- Therefore, for copying arguments and results, we provide different
147 -- functions to pass the arguments in an overflow area and to pass them in spill slots.
148 copyInOflow :: Convention -> Area -> CmmFormals -> (Int, CmmAGraph)
149 copyInSlot :: Convention -> CmmFormals -> CmmAGraph
150 copyOutOflow :: Convention -> Transfer -> Area -> CmmActuals -> UpdFrameOffset ->
152 copyOutSlot :: Convention -> [LocalReg] -> [Middle]
153 -- why a list of middles here instead of an AGraph?
155 copyInOflow = copyIn oneCopyOflowI
156 copyInSlot c f = snd $ copyIn oneCopySlotI c (panic "no area for copying to slots") f
158 type SlotCopier = Area -> (LocalReg, ByteOff) -> (ByteOff, CmmAGraph) ->
160 type CopyIn = SlotCopier -> Convention -> Area -> CmmFormals -> (ByteOff, CmmAGraph)
162 -- Return the number of bytes used for copying arguments, as well as the
163 -- instructions to copy the arguments.
165 copyIn oflow conv area formals =
166 foldr ci (init_offset, mkNop) args'
167 where ci (reg, RegisterParam r) (n, ms) =
168 (n, mkAssign (CmmLocal reg) (CmmReg $ CmmGlobal r) <*> ms)
169 ci (r, StackParam off) (n, ms) = oflow area (r, off) (n, ms)
170 init_offset = widthInBytes wordWidth -- infotable
171 args = assignArgumentsPos conv localRegType formals
172 args' = foldl adjust [] args
173 where adjust rst (v, StackParam off) = (v, StackParam (off + init_offset)) : rst
174 adjust rst x@(_, RegisterParam _) = x : rst
176 -- Copy-in one arg, using overflow space if needed.
177 oneCopyOflowI, oneCopySlotI :: SlotCopier
178 oneCopyOflowI area (reg, off) (n, ms) =
179 (max n off, mkAssign (CmmLocal reg) (CmmLoad (CmmStackSlot area off) ty) <*> ms)
180 where ty = localRegType reg
182 -- Copy-in one arg, using spill slots if needed -- used for calling conventions at
183 -- a procpoint that is not a return point. The offset is irrelevant here...
184 oneCopySlotI _ (reg, _) (n, ms) =
185 (n, mkAssign (CmmLocal reg) (CmmLoad (CmmStackSlot (RegSlot reg) w) ty) <*> ms)
186 where ty = localRegType reg
187 w = widthInBytes (typeWidth ty)
190 -- Factoring out the common parts of the copyout functions yielded something
193 -- The argument layout function ignores the pointer to the info table, so we slot that
194 -- in here. When copying-out to a young area, we set the info table for return
195 -- and adjust the offsets of the other parameters.
196 -- If this is a call instruction, we adjust the offsets of the other parameters.
197 copyOutOflow conv transfer area@(CallArea a) actuals updfr_off =
198 foldr co (init_offset, []) args'
199 where co (v, RegisterParam r) (n, ms) = (n, MidAssign (CmmGlobal r) v : ms)
200 co (v, StackParam off) (n, ms) =
201 (max n off, MidStore (CmmStackSlot area off) v : ms)
202 (setRA, init_offset) =
203 case a of Young id@(BlockId _) -> -- set RA if making a call
204 if transfer == Call then
205 ([(CmmLit (CmmBlock id), StackParam init_offset)],
206 widthInBytes wordWidth)
208 Old -> ([], updfr_off)
209 args = assignArgumentsPos conv cmmExprType actuals
210 args' = foldl adjust setRA args
211 where adjust rst (v, StackParam off) = (v, StackParam (off + init_offset)) : rst
212 adjust rst x@(_, RegisterParam _) = x : rst
213 copyOutOflow _ _ (RegSlot _) _ _ = panic "cannot copy arguments into a register slot"
215 -- Args passed only in registers and stack slots; no overflow space.
216 -- No return address may apply!
217 copyOutSlot conv actuals = foldr co [] args
218 where co (v, RegisterParam r) ms = MidAssign (CmmGlobal r) (toExp v) : ms
219 co (v, StackParam off) ms =
220 MidStore (CmmStackSlot (RegSlot v) off) (toExp v) : ms
221 toExp r = CmmReg (CmmLocal r)
222 args = assignArgumentsPos conv localRegType actuals
224 -- oneCopySlotO _ (reg, _) (n, ms) =
225 -- (n, MidStore (CmmStackSlot (RegSlot reg) w) reg : ms)
226 -- where w = widthInBytes (typeWidth (localRegType reg))
228 mkEntry :: BlockId -> Convention -> CmmFormals -> (Int, CmmAGraph)
229 mkEntry _ conv formals = copyInOflow conv (CallArea Old) formals
231 lastWithArgs :: Transfer -> Area -> Convention -> CmmActuals -> UpdFrameOffset ->
232 (ByteOff -> Last) -> CmmAGraph
233 lastWithArgs transfer area conv actuals updfr_off last =
234 let (outArgs, copies) = copyOutOflow conv transfer area actuals updfr_off in
235 mkMiddles copies <*> mkLast (last outArgs)
237 -- The area created for the jump and return arguments is the same area as the
241 toCall :: CmmExpr -> Maybe BlockId -> UpdFrameOffset -> ByteOff -> ByteOff -> Last
242 toCall e cont updfr_off res_space arg_space =
243 LastCall e cont arg_space res_space (Just updfr_off)
244 mkJump e actuals updfr_off =
245 lastWithArgs Jump old NativeNodeCall actuals updfr_off $ toCall e Nothing updfr_off 0
246 mkJumpGC e actuals updfr_off =
247 lastWithArgs Jump old GC actuals updfr_off $ toCall e Nothing updfr_off 0
248 mkForeignJump conv e actuals updfr_off =
249 lastWithArgs Jump old conv actuals updfr_off $ toCall e Nothing updfr_off 0
250 mkReturn e actuals updfr_off =
251 lastWithArgs Ret old NativeReturn actuals updfr_off $ toCall e Nothing updfr_off 0
252 -- where e = CmmLoad (CmmStackSlot (CallArea Old) updfr_off) gcWord
253 mkReturnSimple actuals updfr_off =
254 lastWithArgs Ret old NativeReturn actuals updfr_off $ toCall e Nothing updfr_off 0
255 where e = CmmLoad (CmmStackSlot (CallArea Old) updfr_off) gcWord
257 mkFinalCall f _ actuals updfr_off =
258 lastWithArgs Call old NativeDirectCall actuals updfr_off $ toCall f Nothing updfr_off 0
260 mkCmmCall f results actuals = mkCall f (NativeDirectCall, NativeReturn) results actuals
262 -- I'm dropping the SRT, but that should be okay: we plan to reconstruct it later.
263 mkCall f (callConv, retConv) results actuals updfr_off =
264 withFreshLabel "call successor" $ \k ->
265 let area = CallArea $ Young k
266 (off, copyin) = copyInOflow retConv area results
267 copyout = lastWithArgs Call area callConv actuals updfr_off
268 (toCall f (Just k) updfr_off off)
269 in (copyout <*> mkLabel k <*> copyin)