From 8bcb01b5fe1976556ec74f682128fb0a2eb75586 Mon Sep 17 00:00:00 2001
From: simonmar <unknown>
Date: Tue, 1 Feb 2005 15:08:06 +0000
Subject: [PATCH] [project @ 2005-02-01 15:08:06 by simonmar] small perf hack
 in emitVectoredReturnInstr: work around lack of CSE in the
 NCG by assigning info_amode to a new temporary.

---
 ghc/compiler/codeGen/CgInfoTbls.hs |    9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/ghc/compiler/codeGen/CgInfoTbls.hs b/ghc/compiler/codeGen/CgInfoTbls.hs
index 7692e7d..981b4b0 100644
--- a/ghc/compiler/codeGen/CgInfoTbls.hs
+++ b/ghc/compiler/codeGen/CgInfoTbls.hs
@@ -44,7 +44,8 @@ import CgCallConv	( isBigLiveness, mkLivenessCLit, buildContLiveness,
 			  CtrlReturnConvention(..) )
 import CgUtils		( mkStringCLit, packHalfWordsCLit, mkWordCLit, 
 			  cmmOffsetB, cmmOffsetExprW, cmmLabelOffW, cmmOffsetW,
-			  emitDataLits, emitRODataLits, emitSwitch, cmmNegate )
+			  emitDataLits, emitRODataLits, emitSwitch, cmmNegate,
+			  newTemp )
 import CgMonad
 
 import CmmUtils		( mkIntCLit, zeroCLit )
@@ -348,7 +349,11 @@ emitVectoredReturnInstr :: CmmExpr	-- *Zero-indexed* constructor tag
 			-> Code
 emitVectoredReturnInstr zero_indexed_tag
   = do	{ info_amode <- getSequelAmode
-	; let target = retVec info_amode zero_indexed_tag
+		-- HACK! assign info_amode to a temp, because retVec
+		-- uses it twice and the NCG doesn't have any CSE yet.
+	; x <- newTemp wordRep
+	; stmtC (CmmAssign x info_amode)
+	; let target = retVec (CmmReg x) zero_indexed_tag
 	; stmtC (CmmJump target []) }
 
 
-- 
1.7.10.4