import CmmExpr
import Cmm ( GenCmm(..), GenCmmTop(..), CmmStatic, CmmInfo
- , CmmCallTarget(..), CmmActuals, CmmFormalsWithoutKinds, CmmFormals
- , CmmStmt(CmmJump, CmmSwitch) -- imported in order to call ppr
+ , CmmCallTarget(..), CmmActuals, CmmFormals
+ , CmmStmt(CmmSwitch) -- imported in order to call ppr
)
import PprCmm()
import Outputable
import Prelude hiding (zip, unzip, last)
+----------------------------------------------------------------------
+----- Type synonyms and definitions
+
type CmmGraph = LGraph Middle Last
type CmmAGraph = AGraph Middle Last
type CmmBlock = Block Middle Last
CmmFormals -- zero or more results
CmmActuals -- zero or more arguments
- | CopyIn -- Move parameters or results from conventional locations to registers
- -- Note [CopyIn invariant]
+ | CopyIn -- Move incoming parameters or results from conventional
+ -- locations to registers. Note [CopyIn invariant]
Convention
CmmFormals -- eventually [CmmKind] will be used only for foreign
-- calls and will migrate into 'Convention' (helping to
- -- drain "the swamp")
+ -- drain "the swamp"), leaving this as [LocalReg]
C_SRT -- Static things kept alive by this block
+
| CopyOut Convention CmmActuals
+ -- Move outgoing parameters or results from registers to
+ -- conventional locations. Every 'LastReturn',
+ -- 'LastJump', or 'LastCall' must be dominated by a
+ -- matching 'CopyOut' in the same basic block.
+ -- As above, '[CmmKind]' will migrate into the foreign calling
+ -- convention, leaving the actuals as '[CmmExpr]'.
data Last
- = LastReturn CmmActuals -- Return from a function,
- -- with these return values.
-
- | LastJump CmmExpr CmmActuals
- -- Tail call to another procedure
-
- | LastBranch BlockId CmmFormalsWithoutKinds
- -- To another block in the same procedure
- -- The parameters are unused at present.
-
- | LastCall { -- A call (native or safe foreign)
- cml_target :: CmmExpr, -- never a CmmPrim to a CallishMachOp!
- cml_next :: Maybe BlockId } -- BlockId of continuation, if call returns
+ = LastBranch BlockId -- Goto another block in the same procedure
| LastCondBranch { -- conditional branch
cml_pred :: CmmExpr,
cml_true, cml_false :: BlockId
}
+ | LastReturn -- Return from a function; values in a previous CopyOut node
+
+ | LastJump CmmExpr -- Tail call to another procedure; args in a CopyOut node
+
+ | LastCall { -- A call (native or safe foreign)
+ cml_target :: CmmExpr, -- never a CmmPrim to a CallishMachOp!
+ cml_cont :: Maybe BlockId } -- BlockId of continuation, if call returns
+
| LastSwitch CmmExpr [Maybe BlockId] -- Table branch
-- The scrutinee is zero-based;
-- zero -> first block
data Convention
= ConventionStandard CCallConv ValueDirection
| ConventionPrivate
- -- Used for control transfers within a (pre-CPS) procedure
- -- All jump sites known, never pushed on the stack (hence no SRT)
- -- You can choose whatever calling convention
- -- you please (provided you make sure
- -- all the call sites agree)!
+ -- Used for control transfers within a (pre-CPS) procedure All
+ -- jump sites known, never pushed on the stack (hence no SRT)
+ -- You can choose whatever calling convention you please
+ -- (provided you make sure all the call sites agree)!
+ -- This data type eventually to be extended to record the convention.
+
deriving Eq
data ValueDirection = Arguments | Results
{-
Note [CopyIn invariant]
~~~~~~~~~~~~~~~~~~~~~~~
-In principle, CopyIn ought to be a First node, but in practice, the
+One might wish for CopyIn to be a First node, but in practice, the
possibility raises all sorts of hairy issues with graph splicing,
rewriting, and so on. In the end, NR finds it better to make the
-placement of CopyIn a dynamic invariant. This change will complicate
-the dataflow fact for the proc-point calculation, but it should make
-things easier in many other respects.
+placement of CopyIn a dynamic invariant; it should normally be the first
+Middle node in the basic block in which it occurs.
-}
+----------------------------------------------------------------------
+----- Instance declarations for control flow
+
instance HavingSuccessors Last where
succs = cmmSuccs
fold_succs = fold_cmm_succs
instance LastNode Last where
- mkBranchNode id = LastBranch id []
- isBranchNode (LastBranch _ []) = True
+ mkBranchNode id = LastBranch id
+ isBranchNode (LastBranch _) = True
isBranchNode _ = False
- branchNodeTarget (LastBranch id []) = id
+ branchNodeTarget (LastBranch id) = id
branchNodeTarget _ = panic "asked for target of non-branch"
cmmSuccs :: Last -> [BlockId]
cmmSuccs (LastReturn {}) = []
cmmSuccs (LastJump {}) = []
-cmmSuccs (LastBranch id _) = [id]
+cmmSuccs (LastBranch id) = [id]
cmmSuccs (LastCall _ (Just id)) = [id]
cmmSuccs (LastCall _ Nothing) = []
cmmSuccs (LastCondBranch _ t f) = [f, t] -- meets layout constraint
fold_cmm_succs :: (BlockId -> a -> a) -> Last -> a -> a
fold_cmm_succs _f (LastReturn {}) z = z
fold_cmm_succs _f (LastJump {}) z = z
-fold_cmm_succs f (LastBranch id _) z = f id z
+fold_cmm_succs f (LastBranch id) z = f id z
fold_cmm_succs f (LastCall _ (Just id)) z = f id z
fold_cmm_succs _f (LastCall _ Nothing) z = z
fold_cmm_succs f (LastCondBranch _ te fe) z = f te (f fe z)
fold_cmm_succs f (LastSwitch _ edges) z = foldl (flip f) z $ catMaybes edges
-----------------------------------------------------------------
--- prettyprinting (avoids recursive imports)
+----------------------------------------------------------------------
+----- Instance declarations for prettyprinting (avoids recursive imports)
instance Outputable Middle where
ppr s = pprMiddle s
ptext SLIT("foreign") <+> doubleQuotes(ppr conv) <+> ptext SLIT("...")
CopyOut conv args ->
- if null args then empty
- else ptext SLIT("CopyOut") <+> doubleQuotes(ppr conv) <+>
- parens (commafy (map pprHinted args))
+ ptext SLIT("next, pass") <+> doubleQuotes(ppr conv) <+>
+ parens (commafy (map pprHinted args))
-- // text
MidComment s -> text "//" <+> ftext s
pprLast :: Last -> SDoc
pprLast stmt = (case stmt of
- LastBranch ident args -> genBranchWithArgs ident args
+ LastBranch ident -> ptext SLIT("goto") <+> ppr ident <> semi
LastCondBranch expr t f -> genFullCondBranch expr t f
- LastJump expr params -> ppr $ CmmJump expr params
- LastReturn results -> hcat [ ptext SLIT("return"), space
- , parens ( commafy $ map pprHinted results )
- , semi ]
+ LastJump expr -> hcat [ ptext SLIT("jump"), space, pprFun expr
+ , ptext SLIT("(...)"), semi]
+ LastReturn -> hcat [ ptext SLIT("return"), space
+ , ptext SLIT("(...)"), semi]
LastSwitch arg ids -> ppr $ CmmSwitch arg ids
LastCall tgt k -> genBareCall tgt k
) <>
genBareCall :: CmmExpr -> Maybe BlockId -> SDoc
genBareCall fn k =
- hcat [ ptext SLIT("foreign"), space
- , doubleQuotes(ptext SLIT("<convention from CopyOut>")), space
- , target fn, parens ( ptext SLIT("<parameters from CopyOut>") ), space
+ hcat [ ptext SLIT("call"), space
+ , pprFun fn, ptext SLIT("(...)"), space
, case k of Nothing -> ptext SLIT("never returns")
Just k -> ptext SLIT("returns to") <+> ppr k
, semi ]
where
- target t@(CmmLit _) = ppr t
- target fn' = parens (ppr fn')
-genBranchWithArgs :: (Outputable id, Outputable arg) => id -> [arg] -> SDoc
-genBranchWithArgs ident [] = ptext SLIT("goto") <+> ppr ident <> semi
-genBranchWithArgs ident args = ptext SLIT("goto") <+> ppr ident <+>
- parens (commafy (map ppr args)) <> semi
+pprFun :: CmmExpr -> SDoc
+pprFun f@(CmmLit _) = ppr f
+pprFun f = parens (ppr f)
genFullCondBranch :: Outputable id => CmmExpr -> id -> id -> SDoc
genFullCondBranch expr t f =
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