[kaffe] PATCH: consistently separate jitter and backend register ID

[Casey Marshall]

--=-=-=

-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1

>>>>> "Timothy" == Timothy Stack <stack@cs.utah.edu> writes:

>>  > Working on the MIPS JIT3 I have made some small changes to the >
>> architechture-independent register code for JIT3 that at least
>> allow > the MIPS JIT to pass all the tests in test/internal. To
>> summarize, > slotRegister now returns the `jitter ID' of the
>> assigned register (the > index into the reginfo array), instead of
>> the `backend ID'. All code > that depends on the former is
>> unchanged, and all code that depends on > the latter now uses a new
>> macro, `slotRegisterRegister', that is > equivalent to
>> slotRegister, but returns the backend ID.
>> 
>> Okie, I'll take a look at this and check it in tonight/tomorrow
>> morning.

Timothy> I looked at the patch, but I'm not totally convinced its the
Timothy> right thing to do...

Me neither. I instead changed `slotAlias' to use regno, and not the
return value of `slotRegister'.

However, I tried something similar to this on x86 and it didn't
work. I haven't tried this approach (attached) on x86 yet.

Timothy> I'd really prefer something that had stronger typing so that
Timothy> these mistakes don't continue to happen.  For example, the
Timothy> x86 backend mixes up uses of the jitter ID for a register and
Timothy> the backend ID.  Its a little trivial, but still...

I'm in favor of Kevin's idea of renaming one of the two `regno'
members in the two structs (`kregs' and `SlotData').

Cheers,

- -- 
Casey Marshall || rsdio@metastatic.org
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.2.3 (GNU/Linux)
Comment: Processed by Mailcrypt 3.5.7 <http://mailcrypt.sourceforge.net/>

iD8DBQFAVfHigAuWMgRGsWsRAsv9AJwL06bDJnTSYxJUfSkYGO4es9EFuwCfVKBI
LUqHxizwTTg9Kas4Q3p333Y=
=bx2x
-----END PGP SIGNATURE-----

--=-=-=
Content-Type: text/x-patch
Content-Disposition: attachment; filename=slotAlias.patch

Index: kaffe/kaffevm/jit3/machine.c
===================================================================
RCS file: /cvs/kaffe/kaffe/kaffe/kaffevm/jit3/machine.c,v
retrieving revision 1.48
diff -u -r1.48 machine.c
--- kaffe/kaffevm/jit3/machine.c	8 Mar 2004 21:21:13 -0000	1.48
+++ kaffe/kaffevm/jit3/machine.c	15 Mar 2004 18:04:03 -0000
@@ -1115,6 +1115,9 @@
 	type = s->u[1].value.i;
 	from = s->u[2].slot;
 
+	if (from->regno == NOREG) {
+		slotRegister(from, type, rread, NOREG);
+	}
 	if (reginfo[from->regno].flags & Rreadonce) {
 		/*
 		 * XXX Aggressively spill the floating point register on x86.
@@ -1138,7 +1141,7 @@
 	/* Get the register we're aliasing and attach the 'to' slot
 	 * to it.
 	 */
-	reg = slotRegister(from, type, rread, NOREG);
+	reg = from->regno;
 	reginfo[reg].refs++;
 	to->regno = reg;
 	to->modified = rwrite;

--=-=-=--