From f20b0d8aa7f04fe42d4bebfb78317b2969f92b07 Mon Sep 17 00:00:00 2001
From: "Ben.Lippmeier@anu.edu.au" <unknown>
Date: Tue, 19 May 2009 03:55:28 +0000
Subject: [PATCH] Don't try and coalesce RealReg->RealReg moves

---
 compiler/nativeGen/RegAlloc/Graph/Main.hs |   10 +++++++---
 1 file changed, 7 insertions(+), 3 deletions(-)

diff --git a/compiler/nativeGen/RegAlloc/Graph/Main.hs b/compiler/nativeGen/RegAlloc/Graph/Main.hs
index 94b18ae..d239d0d 100644
--- a/compiler/nativeGen/RegAlloc/Graph/Main.hs
+++ b/compiler/nativeGen/RegAlloc/Graph/Main.hs
@@ -311,9 +311,13 @@ graphAddCoalesce (r1, r2) graph
 		(vr2, classOfVirtualReg vr2) 
 		graph
 
-	| otherwise
-	= panic "RegAlloc.Graph.Main.graphAddCoalesce: can't coalesce two real regs"
-
+	-- We can't coalesce two real regs, but there could well be existing
+	--	hreg,hreg moves in the input code. We'll just ignore these
+	--	for coalescing purposes.
+	| RegReal _		<- r1
+	, RegReal _	 	<- r2
+	= graph
+	
 
 -- | Patch registers in code using the reg -> reg mapping in this graph.
 patchRegsFromGraph 
-- 
1.7.10.4