change of representation for GenCmm, GenCmmTop, CmmProc

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

diff --git a/compiler/cmm/Cmm.hs b/compiler/cmm/Cmm.hs
index 5b3ad16..0ba437c 100644 (file)
--- a/compiler/cmm/Cmm.hs
+++ b/compiler/cmm/Cmm.hs
@@ -9,9 +9,11 @@
 module Cmm ( 
        GenCmm(..), Cmm, RawCmm,
        GenCmmTop(..), CmmTop, RawCmmTop,
+        ListGraph(..),
        CmmInfo(..), UpdateFrame(..),
         CmmInfoTable(..), ClosureTypeInfo(..), ProfilingInfo(..), ClosureTypeTag,
        GenBasicBlock(..), CmmBasicBlock, blockId, blockStmts, mapBlockStmts,
+        CmmReturnInfo(..),
        CmmStmt(..), CmmActuals, CmmFormal, CmmFormals, CmmHintFormals,
         CmmSafety(..),
        CmmCallTarget(..),
@@ -49,45 +51,45 @@ import Data.Word
 -- GenCmm is abstracted over
 --   d, the type of static data elements in CmmData
 --   h, the static info preceding the code of a CmmProc
---   i, the contents of a basic block within a CmmProc
+--   g, the control-flow graph of a CmmProc
 --
 -- We expect there to be two main instances of this type:
 --   (a) C--, i.e. populated with various C-- constructs
 --             (Cmm and RawCmm below)
 --   (b) Native code, populated with data/instructions
 --
-newtype GenCmm d h i = Cmm [GenCmmTop d h i]
+newtype GenCmm d h g = Cmm [GenCmmTop d h g]
 
 -- | A top-level chunk, abstracted over the type of the contents of
 -- the basic blocks (Cmm or instructions are the likely instantiations).
-data GenCmmTop d h i
+data GenCmmTop d h g
   = CmmProc    -- A procedure
      h                -- Extra header such as the info table
      CLabel            -- Used to generate both info & entry labels
      CmmFormals        -- Argument locals live on entry (C-- procedure params)
-     [GenBasicBlock i] -- Code, may be empty.  The first block is
-                       -- the entry point, and should be labelled by the code gen
-                      -- with the CLabel.  The order is otherwise initially 
-                       -- unimportant, but at some point the code gen will
-                       -- fix the order.
-
-                      -- The BlockId of the first block does not give rise
-                      -- to a label.  To jump to the first block in a Proc,
-                      -- use the appropriate CLabel.
-
-                      -- BlockIds are only unique within a procedure
+     g                 -- Control-flow graph for the procedure's code
 
   | CmmData    -- Static data
        Section 
        [d]
 
+-- | A control-flow graph represented as a list of extended basic blocks.
+newtype ListGraph i = ListGraph [GenBasicBlock i] 
+   -- ^ Code, may be empty.  The first block is the entry point.  The
+   -- order is otherwise initially unimportant, but at some point the
+   -- code gen will fix the order.
+
+   -- BlockIds must be unique across an entire compilation unit, since
+   -- they are translated to assembly-language labels, which scope
+   -- across a whole compilation unit.
+
 -- | Cmm with the info table as a data type
-type Cmm    = GenCmm    CmmStatic CmmInfo CmmStmt
-type CmmTop = GenCmmTop CmmStatic CmmInfo CmmStmt
+type Cmm    = GenCmm    CmmStatic CmmInfo (ListGraph CmmStmt)
+type CmmTop = GenCmmTop CmmStatic CmmInfo (ListGraph CmmStmt)
 
 -- | Cmm with the info tables converted to a list of 'CmmStatic'
-type RawCmm    = GenCmm    CmmStatic [CmmStatic] CmmStmt
-type RawCmmTop = GenCmmTop CmmStatic [CmmStatic] CmmStmt
+type RawCmm    = GenCmm    CmmStatic [CmmStatic] (ListGraph CmmStmt)
+type RawCmmTop = GenCmmTop CmmStatic [CmmStatic] (ListGraph CmmStmt)
 
 
 -- A basic block containing a single label, at the beginning.
@@ -107,6 +109,7 @@ blockId (BasicBlock blk_id _ ) = blk_id
 blockStmts :: GenBasicBlock i -> [i]
 blockStmts (BasicBlock _ stmts) = stmts
 
+mapBlockStmts :: (i -> i') -> GenBasicBlock i -> GenBasicBlock i'
 mapBlockStmts f (BasicBlock id bs) = BasicBlock id (map f bs)
 
 -----------------------------------------------------------------------------
@@ -140,6 +143,9 @@ data ClosureTypeInfo
       [Maybe LocalReg]  -- Forced stack parameters
       C_SRT
 
+data CmmReturnInfo = CmmMayReturn
+                   | CmmNeverReturns
+
 -- TODO: These types may need refinement
 data ProfilingInfo = ProfilingInfo CmmLit CmmLit -- closure_type, closure_desc
 type ClosureTypeTag = StgHalfWord
@@ -181,6 +187,7 @@ data CmmStmt
      CmmHintFormals             -- zero or more results
      CmmActuals                         -- zero or more arguments
      CmmSafety                  -- whether to build a continuation
+     CmmReturnInfo
 
   | CmmBranch BlockId             -- branch to another BB in this fn
 
@@ -332,6 +339,7 @@ cmmRegRep (CmmGlobal reg)   = globalRegRep reg
 localRegRep :: LocalReg -> MachRep
 localRegRep (LocalReg _ rep _) = rep
 
+localRegGCFollow :: LocalReg -> Kind
 localRegGCFollow (LocalReg _ _ p) = p
 
 cmmLitRep :: CmmLit -> MachRep