don't pass trash in MSB bits to write8 and write16 handlers

[cyclone68000.git] / OpMove.cpp

diff --git a/OpMove.cpp b/OpMove.cpp
index 3d893de..44842ee 100644 (file)
--- a/OpMove.cpp
+++ b/OpMove.cpp
@@ -96,6 +96,7 @@ void SuperChange(int op,int srh_reg)
 // Emit a Move opcode, 00xxdddd ddssssss\r
 int OpMove(int op)\r
 {\r
+  EaRWType eatype;\r
   int sea=0,tea=0;\r
   int size=0,use=0;\r
   int movea=0;\r
@@ -133,13 +134,25 @@ int OpMove(int op)
 \r
   if (movea==0)\r
   {\r
-    EaCalcRead(-1,1,sea,size,0x003f,earwt_sign_extend,1);\r
-    OpGetFlagsNZ(1);\r
+    if (sea < 0x10 && size < 2)\r
+    {\r
+      eatype = earwt_zero_extend;\r
+      EaCalcRead(-1,1,sea,size,0x003f,eatype);\r
+      ot("  movs r2,r1,lsl #%d\n",size?16:24);\r
+      OpGetFlagsNZ(2);\r
+    }\r
+    else\r
+    {\r
+      eatype = earwt_shifted_up;\r
+      EaCalcRead(-1,1,sea,size,0x003f,eatype,1);\r
+      OpGetFlagsNZ(1);\r
+    }\r
     ot("\n");\r
   }\r
   else\r
   {\r
-    EaCalcRead(-1,1,sea,size,0x003f,earwt_sign_extend);\r
+    eatype = earwt_sign_extend;\r
+    EaCalcRead(-1,1,sea,size,0x003f,eatype);\r
     size=2; // movea always expands to 32-bits\r
   }\r
 \r
@@ -155,8 +168,8 @@ int OpMove(int op)
   else\r
 #endif\r
   {\r
-    EaCalc (0,0x0e00,tea,size,earwt_msb_dont_care);\r
-    EaWrite(0,     1,tea,size,0x0e00,earwt_msb_dont_care);\r
+    EaCalc (0,0x0e00,tea,size,eatype);\r
+    EaWrite(0,     1,tea,size,0x0e00,eatype);\r
   }\r
 \r
 #if CYCLONE_FOR_GENESIS && !MEMHANDLERS_CHANGE_CYCLES\r