From 48f77ccca1446999be4373acf7fd1a667aaf6f4d Mon Sep 17 00:00:00 2001
From: simonmar <unknown>
Date: Wed, 15 Jun 2005 13:50:14 +0000
Subject: [PATCH] [project @ 2005-06-15 13:50:14 by simonmar] Undo accidental
 commit

---
 ghc/compiler/nativeGen/RegisterAlloc.hs |   52 -------------------------------
 1 file changed, 52 deletions(-)

diff --git a/ghc/compiler/nativeGen/RegisterAlloc.hs b/ghc/compiler/nativeGen/RegisterAlloc.hs
index 303d8a6..1295f9c 100644
--- a/ghc/compiler/nativeGen/RegisterAlloc.hs
+++ b/ghc/compiler/nativeGen/RegisterAlloc.hs
@@ -80,58 +80,6 @@ The algorithm is roughly:
 
 -}
 
-{-
-Possible plan for x86 floating pt register alloc:
-
-  - The standard reg alloc procedure allocates pretend floating point
-    registers to the GXXX instructions.  We need to convert these GXXX
-    instructions to proper x86 FXXX instructions, using the FP stack for
-    registers.
-
-    We could do this in a separate pass, but it helps to have the
-    information about which real registers are live after the
-    instruction, so we do it at reg alloc time where that information
-    is already available.
-
-  - keep a mapping from %fakeN to FP stack slot in the monad.
-
-  - after assigning registers to the GXXX instruction, convert the
-    instruction to an FXXX instruction.  eg. 
-	- for GMOV just update the mapping, and ffree any dead regs.
-	- GLD:  just fld and update mapping
-	  GLDZ: just fldz and update mapping
-	  GLD1: just fld1 and update mapping
-	- GST: just fst and update mapping, ffree dead regs.
-	   - special case for GST reg, where reg is st(0), we can fstp.
-	- for GADD fp1, fp2, fp3:
-	  - easy way: fld fp2
-		      fld fp1
-		      faddp
-		      -- record that fp3 is now in %st(0), and all other
-		      -- slots are pushed down one.
-		      ffree fp1 -- if fp1 is dead now
-		      ffree fp2 -- if fp2 is dead now
-	  - optimisation #1
-	    - if fp1 is in %st(0) and is dead afterward
-		fadd %st(0), fp2
-		-- record fp3 is in %st(0)
-		ffree fp2 -- if fp2 is dead now
-	    - if fp2 is in %st(0) and is dead afterward
-		fadd %st(0), fp1
-		-- record fp3 is in %st(0)
-	    - if fp1 is in %st(0), fp2 is dead afterward
-		fadd fp2, %st(0)
-		-- record fp3 is in fp2's locn
-	    - if fp2 is in %st(0), fp1 is dead afterward
-		fadd fp1, %st(0)
-		-- record fp3 is in fp1's locn
-
-  - we should be able to avoid the nasty ffree problems of the current
-    scheme.  The stack should be empty before doing a non-local
-    jump/call - we can assert that this is the case.
--}
-
-
 module RegisterAlloc (
   	regAlloc
   ) where
-- 
1.7.10.4