From: benl@ouroborus.net <unknown>
Date: Thu, 24 Jun 2010 08:24:37 +0000 (+0000)
Subject: NCG: Reverse SCCs after each round in the graph allocator
X-Git-Url: http://git.megacz.com/?p=ghc-hetmet.git;a=commitdiff_plain;h=c66391a745efa86bab4e9659e4d04ba514359164

NCG: Reverse SCCs after each round in the graph allocator
---

diff --git a/compiler/nativeGen/RegAlloc/Liveness.hs b/compiler/nativeGen/RegAlloc/Liveness.hs
index 61e800f..cc1bf12 100644
--- a/compiler/nativeGen/RegAlloc/Liveness.hs
+++ b/compiler/nativeGen/RegAlloc/Liveness.hs
@@ -27,6 +27,7 @@ module RegAlloc.Liveness (
 	eraseDeltasLive,
 	patchEraseLive,
 	patchRegsLiveInstr,
+	reverseBlocksInTops,
 	regLiveness,
 	natCmmTopToLive
   ) where
@@ -670,9 +671,6 @@ regLiveness (CmmProc info lbl params sccs)
 			   lbl params ann_sccs
 
 
-
-
-
 -- -----------------------------------------------------------------------------
 -- | Check ordering of Blocks
 --	The computeLiveness function requires SCCs to be in reverse dependent order.
@@ -711,8 +709,17 @@ checkIsReverseDependent sccs'
 	 	= unionManyUniqSets
 		$ map (mkUniqSet . jumpDestsOfInstr) 
 		 	[ i | LiveInstr i _ <- instrs]
-	
 
+
+-- | If we've compute liveness info for this code already we have to reverse
+--   the SCCs in each top to get them back to the right order so we can do it again.
+reverseBlocksInTops :: LiveCmmTop instr -> LiveCmmTop instr
+reverseBlocksInTops top
+ = case top of
+	CmmData{}			-> top
+	CmmProc info lbl params sccs	-> CmmProc info lbl params (reverse sccs)
+
+	
 -- | Computing liveness
 -- 	
 --  On entry, the SCCs must be in "reverse" order: later blocks may transfer