1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
|
(*
* This module takes a stream of instructions and build a CFG.
* The building can be incremental.
*
* -- Allen
*)
functor ControlFlowGraphGen
(structure CFG : CONTROL_FLOW_GRAPH
structure Stream : INSTRUCTION_STREAM
structure InsnProps : INSN_PROPERTIES
sharing CFG.I = InsnProps.I
sharing CFG.P = Stream.P
) : CONTROL_FLOW_GRAPH_GEN =
struct
structure CFG = CFG
structure I = CFG.I
structure P = CFG.P
structure G = Graph
structure W = CFG.W
structure S = Stream
fun error msg = MLRiscErrorMsg.error("ControlFlowGraphGen",msg)
fun builder(CFG) =
let val NOBLOCK = CFG.newBlock(~1,ref 0)
val currentBlock = ref NOBLOCK
val newBlocks = ref [] : CFG.block list ref
val blockNames = ref [] : Annotations.annotations ref
val entryLabels = ref [] : Label.label list ref
fun can'tUse _ = error "unimplemented"
exception NotFound
val labelMap = IntHashTable.mkTable(32,NotFound)
val newLabel = IntHashTable.insert labelMap
val lookupLabel = IntHashTable.lookup labelMap
val CFG = ref CFG
(* Initialization *)
fun init _ =
let val G.GRAPH cfg = !CFG
in IntHashTable.clear labelMap;
#forall_nodes cfg
(fn (blockId,CFG.BLOCK{labels, ...}) =>
app (fn Label.Label{id, ...} => newLabel(id,blockId))
(!labels));
currentBlock := NOBLOCK;
newBlocks := [];
blockNames := [];
entryLabels := []
end
val _ = init()
fun next cfg = CFG := cfg
fun newBlock() =
let val G.GRAPH cfg = !CFG
val id = #new_id cfg ()
val b as CFG.BLOCK{annotations,...} = CFG.newBlock(id,ref 0)
in currentBlock := b;
annotations := !blockNames;
newBlocks := b :: !newBlocks;
#add_node cfg (id,b);
b
end
fun getBlock() =
case !currentBlock of
CFG.BLOCK{id= ~1,...} => newBlock()
| b => b
fun newPseudoOpBlock() =
(case !currentBlock of
CFG.BLOCK{id= ~1,...} => newBlock()
| b as CFG.BLOCK{insns=ref [],...} => b
| _ => newBlock()
)
fun insertOp p =
let val CFG.BLOCK{data,...} = newPseudoOpBlock()
in data := !data @ [p] end
(* Add a new label *)
fun defineLabel(l as Label.Label{id=labelId,...}) =
let val id = lookupLabel labelId
val G.GRAPH cfg = !CFG
val blk as CFG.BLOCK{insns, ...} = #node_info cfg id
in currentBlock := blk;
newBlocks := blk :: !newBlocks;
insns := []; (* clear instructions *)
#set_out_edges cfg (id,[]) (* clear edges *)
end handle _ =>
let val CFG.BLOCK{id,labels,...} = newPseudoOpBlock()
in labels := l :: !labels;
newLabel(labelId, id)
end
(* Add a new entry label *)
fun entryLabel l = (defineLabel l; entryLabels := l :: !entryLabels)
(* Add a new pseudo op *)
fun pseudoOp p = insertOp(CFG.PSEUDO p)
fun nextBlock() =
case !currentBlock of
CFG.BLOCK{id= ~1,...} => ()
| b => currentBlock := NOBLOCK
(* Add a new annotation *)
fun annotation a =
case a of
MLRiscAnnotations.BLOCKNAMES names =>
(blockNames := names;
nextBlock()
)
| MLRiscAnnotations.EMPTYBLOCK => nextBlock()
| a =>
let val CFG.BLOCK{annotations,...} = getBlock()
in annotations := a :: !annotations
end
(* Mark current block as exit *)
fun exitBlock liveOut =
let fun setLiveOut(CFG.BLOCK{annotations,...}) =
annotations := #create CFG.LIVEOUT liveOut :: !annotations
in case !currentBlock of
CFG.BLOCK{id= ~1,...} =>
(case !newBlocks of
[] => error "exitBlock"
| b::_ => setLiveOut b
)
| b => setLiveOut b
end
(* Add a new comment *)
fun comment msg = annotation(#create MLRiscAnnotations.COMMENT msg)
(* Emit an instruction *)
fun emit i =
let val CFG.BLOCK{insns,...} = getBlock()
in insns := i :: !insns;
case InsnProps.instrKind i of
(InsnProps.IK_JUMP | InsnProps.IK_CALL_WITH_CUTS) =>
currentBlock := NOBLOCK
| _ => ()
end
(* End current cluster *)
fun endCluster(annotations) =
let val G.GRAPH cfg = !CFG
val _ = CFG.init(!CFG) (* create entry/exit *)
val ENTRY = hd(#entries cfg ())
val EXIT = hd(#exits cfg ())
fun next(CFG.BLOCK{id,data=ref [],...}::_) = id
| next _ = error "next"
val lookupLabelMap = IntHashTable.find labelMap
val lookupLabelMap =
fn l => case lookupLabelMap l of SOME b => b | NONE => EXIT
val TRUE = CFG.BRANCH true
val FALSE = CFG.BRANCH false
val addEdge = #add_edge cfg
fun target(Label.Label{id,...}) = lookupLabelMap id
fun addEdges [] = ()
| addEdges(CFG.BLOCK{id,insns,...}::blocks) =
(case !insns of
[] => fallsThru(id,blocks)
| instr::_ =>
(case InsnProps.instrKind instr of
(InsnProps.IK_JUMP | InsnProps.IK_CALL_WITH_CUTS) =>
jump(id,InsnProps.branchTargets instr,blocks)
| _ => fallsThru(id,blocks)
);
addEdges blocks
)
and fallsThru(i,CFG.BLOCK{id=j,data,...}::_) =
(case !data of
[] => ()
| _ => error("falls thru into pseudo ops: "^
Int.toString i^" -> "^Int.toString j)
;
addEdge(i,j,CFG.EDGE{k=CFG.FALLSTHRU,w=ref 0, a=ref []})
)
| fallsThru(i,[]) =
(* error("missing return in block "^Int.toString i) *)
addEdge(i,EXIT,CFG.EDGE{k=CFG.EXIT,w=ref 0,a=ref []})
and jump(i,[InsnProps.ESCAPES],_) =
addEdge(i,EXIT,CFG.EDGE{k=CFG.EXIT,w=ref 0,a=ref []})
| jump(i,[InsnProps.LABELLED L],_) =
addEdge(i,target L,CFG.EDGE{k=CFG.JUMP,w=ref 0,a=ref []})
| jump(i,[InsnProps.LABELLED L,InsnProps.FALLTHROUGH],bs) =
(addEdge(i,target L,CFG.EDGE{k=TRUE,w=ref 0,a=ref[]});
addEdge(i,next bs,CFG.EDGE{k=FALSE,w=ref 0,a=ref []})
)
| jump(i,[InsnProps.FALLTHROUGH,InsnProps.LABELLED L],bs) =
(addEdge(i,target L,CFG.EDGE{k=TRUE,w=ref 0,a=ref []});
addEdge(i,next bs,CFG.EDGE{k=FALSE,w=ref 0,a=ref []})
)
| jump(i,targets,_) =
let fun loop(n,[]) = ()
| loop(n,InsnProps.LABELLED L::targets) =
(addEdge(i,target L,
CFG.EDGE{k=CFG.SWITCH n,w=ref 0,a=ref []});
loop(n+1,targets))
| loop _ = error "jump"
in loop(0,targets) end
in addEdges(rev(!newBlocks));
app (fn l => addEdge(ENTRY,target l,
CFG.EDGE{k=CFG.ENTRY,a=ref [],w=ref 0}))
(!entryLabels);
let val an = CFG.annotations(!CFG);
in an := annotations @ (!an) end;
init()
end
(* Start a new cluster *)
fun beginCluster _ = init()
fun getAnnotations() = CFG.annotations(!CFG)
in {stream=S.STREAM
{ beginCluster = beginCluster,
endCluster = endCluster,
defineLabel = defineLabel,
entryLabel = entryLabel,
pseudoOp = pseudoOp,
emit = emit,
exitBlock = exitBlock,
comment = comment,
annotation = annotation,
getAnnotations= getAnnotations
},
next = next
}
end
end
|
