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/cmm/CmmUtils.hs b/compiler/cmm/CmmUtils.hs
index d52c6a3a56..c822da9673 100644
--- a/compiler/cmm/CmmUtils.hs
+++ b/compiler/cmm/CmmUtils.hs
@@ -51,9 +51,8 @@ module CmmUtils(
         -- * Operations that probably don't belong here
         modifyGraph,
 
-        lastNode, replaceLastNode,
         ofBlockMap, toBlockMap, insertBlock,
-        ofBlockList, toBlockList, bodyToBlockList,
+        ofBlockList, toBlockList, bodyToBlockList, toBlockListEntryFirst,
         foldGraphBlocks, mapGraphNodes, postorderDfs, mapGraphNodes1,
 
         analFwd, analBwd, analRewFwd, analRewBwd,
@@ -424,6 +423,17 @@ insertBlock block map =
 toBlockList :: CmmGraph -> [CmmBlock]
 toBlockList g = mapElems $ toBlockMap g
 
+-- | like 'toBlockList', but the entry block always comes first
+toBlockListEntryFirst :: CmmGraph -> [CmmBlock]
+toBlockListEntryFirst g
+  | mapNull m  = []
+  | otherwise  = entry_block : others
+  where
+    m = toBlockMap g
+    entry_id = g_entry g
+    Just entry_block = mapLookup entry_id m
+    others = filter ((/= entry_id) . entryLabel) (mapElems m)
+
 ofBlockList :: BlockId -> [CmmBlock] -> CmmGraph
 ofBlockList entry blocks = CmmGraph { g_entry = entry
                                     , g_graph = GMany NothingO body NothingO }