From: benl@ouroborus.net <unknown>
Date: Thu, 24 Jun 2010 08:27:17 +0000 (+0000)
Subject: NCG: Do the actual reversing of SCCs
X-Git-Url: http://git.megacz.com/?p=ghc-hetmet.git;a=commitdiff_plain;h=a4e89052ca5163bc1a33b5096b50e5a3fbb9fbd5

NCG: Do the actual reversing of SCCs
---

diff --git a/compiler/nativeGen/RegAlloc/Graph/Main.hs b/compiler/nativeGen/RegAlloc/Graph/Main.hs
index 6b01298..069c8c0 100644
--- a/compiler/nativeGen/RegAlloc/Graph/Main.hs
+++ b/compiler/nativeGen/RegAlloc/Graph/Main.hs
@@ -212,8 +212,10 @@ regAlloc_spin
 			<- regSpill code_coalesced slotsFree rsSpill
 
 		-- recalculate liveness
---		let code_nat	= map stripLive code_spilled
-		code_relive	<- mapM regLiveness code_spilled
+		-- NOTE: we have to reverse the SCCs here to get them back into the reverse-dependency
+		--       order required by computeLiveness. If they're not in the correct order
+		--       that function will panic.
+		code_relive	<- mapM (regLiveness . reverseBlocksInTops) code_spilled
 
 		-- record what happened in this stage for debugging
 		let stat	=