Factored proc-point analysis into separate file (compiler/cmm/CmmProcPoint)

[ghc-hetmet.git] / compiler / cmm / CmmCPSData.hs

diff --git a/compiler/cmm/CmmCPSData.hs b/compiler/cmm/CmmCPSData.hs
new file mode 100644 (file)
index 0000000..7ea1d40
--- /dev/null
+++ b/compiler/cmm/CmmCPSData.hs
@@ -0,0 +1,74 @@
+module CmmCPSData (
+  blocksToBlockEnv,
+  BrokenBlock(..),
+  BlockEntryInfo(..),
+  FinalStmt(..)
+  ) where
+
+#include "HsVersions.h"
+
+import Cmm
+import CLabel
+
+import UniqFM
+
+-- A minor helper (TODO document)
+blocksToBlockEnv :: [BrokenBlock] -> BlockEnv BrokenBlock
+blocksToBlockEnv blocks = listToUFM $ map (\b -> (brokenBlockId b, b)) blocks
+
+data BrokenBlock
+  = BrokenBlock {
+      brokenBlockId :: BlockId, -- Like a CmmBasicBlock
+      brokenBlockEntry :: BlockEntryInfo,
+                                -- How this block can be entered
+
+      brokenBlockStmts :: [CmmStmt],
+                                -- Like a CmmBasicBlock
+                                -- (but without the last statement)
+
+      brokenBlockTargets :: [BlockId],
+                                -- Blocks that this block could
+                                -- branch to one either by conditional
+                                -- branches or via the last statement
+
+      brokenBlockExit :: FinalStmt
+                                -- How the block can be left
+    }
+
+data BlockEntryInfo
+  = FunctionEntry              -- Beginning of a function
+      CLabel                    -- The function name
+      CmmFormals                -- Aguments to function
+
+  | ContinuationEntry          -- Return point of a call
+      CmmFormals                -- return values (argument to continuation)
+  -- TODO:
+  -- | ProcPointEntry -- no return values, but some live might end up as params or possibly in the frame
+
+  | ControlEntry               -- A label in the input
+
+-- Final statement in a BlokenBlock
+-- Constructors and arguments match those in Cmm,
+-- but are restricted to branches, returns, jumps, calls and switches
+data FinalStmt
+  = FinalBranch
+      BlockId -- next block (must be a ControlEntry)
+
+  | FinalReturn
+      CmmActuals -- return values
+
+  | FinalJump
+      CmmExpr -- the function to call
+      CmmActuals -- arguments to call
+
+  | FinalCall
+      BlockId -- next block after call (must be a ContinuationEntry)
+      CmmCallTarget -- the function to call
+      CmmFormals -- results from call (redundant with ContinuationEntry)
+      CmmActuals -- arguments to call
+      (Maybe [GlobalReg]) -- registers that must be saved (TODO)
+
+  | FinalSwitch
+      CmmExpr [Maybe BlockId]   -- Table branch
+
+  -- TODO: | ProcPointExit (needed?)