2abca3fe16024d7d052ddb77a8ba7473a5401916
[ghc.git] / compiler / codeGen / StgCmmGran.hs
1 -----------------------------------------------------------------------------
2 --
3 -- (c) The University of Glasgow -2006
4 --
5 -- Code generation relaed to GpH
6 -- (a) parallel
7 -- (b) GranSim
8 --
9 -----------------------------------------------------------------------------
10
11 module StgCmmGran (
12 staticGranHdr,staticParHdr,
13 granThunk, granYield,
14 doGranAllocate
15 ) where
16
17 -- This entire module consists of no-op stubs at the moment
18 -- GranSim worked once, but it certainly doesn't any more
19 -- I've left the calls, though, in case anyone wants to resurrect it
20
21 import StgCmmMonad
22 import CmmExpr
23
24 staticGranHdr :: [CmmLit]
25 staticGranHdr = []
26
27 staticParHdr :: [CmmLit]
28 staticParHdr = []
29
30 doGranAllocate :: VirtualHpOffset -> FCode ()
31 -- Must be lazy in the amount of allocation
32 doGranAllocate _ = return ()
33
34 granYield :: [LocalReg] -> Bool -> FCode ()
35 granYield _regs _node_reqd = return ()
36
37 granThunk :: Bool -> FCode ()
38 granThunk _node_points = return ()
39
40 -----------------------------------------------------------------
41 {- ------- Everything below here is commented out -------------
42 -----------------------------------------------------------------
43
44 -- Parallel header words in a static closure
45 staticParHdr :: [CmmLit]
46 -- Parallel header words in a static closure
47 staticParHdr = []
48
49 staticGranHdr :: [CmmLit]
50 -- Gransim header words in a static closure
51 staticGranHdr = []
52
53 doGranAllocate :: CmmExpr -> Code
54 -- macro DO_GRAN_ALLOCATE
55 doGranAllocate hp
56 | not opt_GranMacros = nopC
57 | otherwise = panic "doGranAllocate"
58
59
60
61 -------------------------
62 granThunk :: Bool -> FCode ()
63 -- HWL: insert macros for GrAnSim; 2 versions depending on liveness of node
64 -- (we prefer fetchAndReschedule-style context switches to yield ones)
65 granThunk node_points
66 | node_points = granFetchAndReschedule [] node_points
67 | otherwise = granYield [] node_points
68
69 granFetchAndReschedule :: [(Id,GlobalReg)] -- Live registers
70 -> Bool -- Node reqd?
71 -> Code
72 -- Emit code for simulating a fetch and then reschedule.
73 granFetchAndReschedule regs node_reqd
74 | opt_GranMacros && (node `elem` map snd regs || node_reqd)
75 = do { fetch
76 ; reschedule liveness node_reqd }
77 | otherwise
78 = nopC
79 where
80 liveness = mkRegLiveness regs 0 0
81
82 fetch = panic "granFetch"
83 -- Was: absC (CMacroStmt GRAN_FETCH [])
84 --HWL: generate GRAN_FETCH macro for GrAnSim
85 -- currently GRAN_FETCH and GRAN_FETCH_AND_RESCHEDULE are miai
86
87 reschedule liveness node_reqd = panic "granReschedule"
88 -- Was: absC (CMacroStmt GRAN_RESCHEDULE [
89 -- mkIntCLit (I# (word2Int# liveness_mask)),
90 -- mkIntCLit (if node_reqd then 1 else 0)])
91
92
93 -------------------------
94 -- The @GRAN_YIELD@ macro is taken from JSM's code for Concurrent Haskell. It
95 -- allows to context-switch at places where @node@ is not alive (it uses the
96 -- @Continue@ rather than the @EnterNodeCode@ function in the RTS). We emit
97 -- this kind of macro at the beginning of the following kinds of basic bocks:
98 -- \begin{itemize}
99 -- \item Slow entry code where node is not alive (see @CgClosure.lhs@). Normally
100 -- we use @fetchAndReschedule@ at a slow entry code.
101 -- \item Fast entry code (see @CgClosure.lhs@).
102 -- \item Alternatives in case expressions (@CLabelledCode@ structures), provided
103 -- that they are not inlined (see @CgCases.lhs@). These alternatives will
104 -- be turned into separate functions.
105
106 granYield :: [(Id,GlobalReg)] -- Live registers
107 -> Bool -- Node reqd?
108 -> Code
109
110 granYield regs node_reqd
111 | opt_GranMacros && node_reqd = yield liveness
112 | otherwise = nopC
113 where
114 liveness = mkRegLiveness regs 0 0
115
116 yield liveness = panic "granYield"
117 -- Was : absC (CMacroStmt GRAN_YIELD
118 -- [mkIntCLit (I# (word2Int# liveness_mask))])
119
120 -}