From df333a45edbccd632bb5d42993b1a0ef1b8fbd89 Mon Sep 17 00:00:00 2001
From: "SND\\shalma_cp" <SND\shalma_cp@e17a0e51-4ae3-4d35-97c3-1a29b211df97>
Date: Fri, 5 Nov 2010 01:21:22 +0000
Subject: gte.c - add some extra MAME changes (MTC2) - experimental: not in use

git-svn-id: https://pcsxr.svn.codeplex.com/svn/pcsxr@59188 e17a0e51-4ae3-4d35-97c3-1a29b211df97
---
 libpcsxcore/gte.c | 69 +++++++++++++++++++++++++++++++++++++++----------------
 1 file changed, 49 insertions(+), 20 deletions(-)

(limited to 'libpcsxcore')

diff --git a/libpcsxcore/gte.c b/libpcsxcore/gte.c
index b5acadab..3959294b 100644
--- a/libpcsxcore/gte.c
+++ b/libpcsxcore/gte.c
@@ -267,29 +267,58 @@ static inline void MTC2(u32 value, int reg) {
 
 		case 30:
 			{
-				int a;
-				gteLZCS = value;
-
-				a = gteLZCS;
-				if (a > 0) {
-					int i;
-					for (i = 31; (a & (1 << i)) == 0 && i >= 0; i--);
-					gteLZCR = 31 - i;
-				} else if (a < 0) {
-					int i;
-					a ^= 0xffffffff;
-					for (i = 31; (a & (1 << i)) == 0 && i >= 0; i--);
-					gteLZCR = 31 - i;
-				} else {
-					gteLZCR = 32;
-				}
+#if 1
+				int a;
+				gteLZCS = value;
+
+				// non-MAME code
+				a = gteLZCS;
+				if (a > 0) {
+					int i;
+					for (i = 31; (a & (1 << i)) == 0 && i >= 0; i--);
+					gteLZCR = 31 - i;
+				} else if (a < 0) {
+					int i;
+					a ^= 0xffffffff;
+					for (i = 31; (a & (1 << i)) == 0 && i >= 0; i--);
+					gteLZCR = 31 - i;
+				} else {
+					gteLZCR = 32;
+				}
+#else
+				// MAME
+				u32 lzcs = value;
+				u32 lzcr = 0;
+
+				gteLZCS = value;
+
+				if( ( lzcs & 0x80000000 ) == 0 )
+				{
+					lzcs = ~lzcs;
+				}
+				while( ( lzcs & 0x80000000 ) != 0 )
+				{
+					lzcr++;
+					lzcs <<= 1;
+				}
+				gteLZCR = lzcr;
+#endif
 			}
 			break;
 
-		case 7:
-		case 29:
-		case 31:
-			return;
+#if 1
+		// non-MAME
+		case 7:
+		case 29:
+			return;
+
+		case 31:
+			return;
+#else
+		case 31:
+			value = psxRegs.CP2D.r[reg];
+			break;
+#endif
 
 		default:
 			psxRegs.CP2D.r[reg] = value;
-- 
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