Remove OldCmm, convert backends to consume new Cmm

This removes the OldCmm data type and the CmmCvt pass that converts
new Cmm to OldCmm.  The backends (NCGs, LLVM and C) have all been
converted to consume new Cmm.

The main difference between the two data types is that conditional
branches in new Cmm have both true/false successors, whereas in OldCmm
the false case was a fallthrough.  To generate slightly better code we
occasionally need to invert a conditional to ensure that the
branch-not-taken becomes a fallthrough; this was previously done in
CmmCvt, and it is now done in CmmContFlowOpt.

We could go further and use the Hoopl Block representation for native
code, which would mean that we could use Hoopl's postorderDfs and
analyses for native code, but for now I've left it as is, using the
old ListGraph representation for native code.

1 files changed, 12 insertions, 2 deletions

diff --git a/compiler/nativeGen/Instruction.hs b/compiler/nativeGen/Instruction.hs
index 86f5ae435d..48d6a33d79 100644
--- a/compiler/nativeGen/Instruction.hs
+++ b/compiler/nativeGen/Instruction.hs
@@ -2,9 +2,12 @@
 module Instruction (
         RegUsage(..),
         noUsage,
+        GenBasicBlock(..), blockId,
+        ListGraph(..),
         NatCmm,
         NatCmmDecl,
         NatBasicBlock,
+        topInfoTable,
         Instruction(..)
 )
 
@@ -14,8 +17,9 @@ import Reg
 
 import BlockId
 import DynFlags
-import OldCmm
+import Cmm hiding (topInfoTable)
 import Platform
+import Outputable
 
 -- | Holds a list of source and destination registers used by a
 --      particular instruction.
@@ -34,7 +38,6 @@ data RegUsage
 noUsage :: RegUsage
 noUsage  = RU [] []
 
-
 -- Our flavours of the Cmm types
 -- Type synonyms for Cmm populated with native code
 type NatCmm instr
@@ -54,6 +57,13 @@ type NatBasicBlock instr
         = GenBasicBlock instr
 
 
+-- | Returns the info table associated with the CmmDecl's entry point,
+-- if any.
+topInfoTable :: GenCmmDecl a (BlockEnv i) (ListGraph b) -> Maybe i
+topInfoTable (CmmProc infos _ _ (ListGraph (b:_)))
+  = mapLookup (blockId b) infos
+topInfoTable _
+  = Nothing
 
 
 -- | Common things that we can do with instructions, on all architectures.