more MAME fixes, some optimization

[picodrive.git] / cpu / Cyclone / config.h

diff --git a/cpu/Cyclone/config.h b/cpu/Cyclone/config.h
index a7f6a75..0fc96cb 100644 (file)
--- a/cpu/Cyclone/config.h
+++ b/cpu/Cyclone/config.h
@@ -42,12 +42,18 @@
  * count in ARM registers instead of the context for performance reasons. If you for\r
  * any reason need to access them in your memory handlers, enable the options below,\r
  * otherwise disable them to improve performance.\r
- * PC value will point to start of instruction currently executed.\r
+ * MEMHANDLERS_NEED_PC updates .pc context field with PC value effective at the time\r
+ * when memhandler was called (opcode address + unknown amount).\r
+ * MEMHANDLERS_NEED_PREV_PC updates .prev_pc context field to currently executed\r
+ * opcode address.\r
+ * Note that .pc and .prev_pc values are always real pointers to memory, so you must\r
+ * subtract .membase to get M68k PC value.\r
  * Warning: updating PC in memhandlers is dangerous, as Cyclone may internally\r
  * increment the PC before fetching the next instruction and continue executing\r
  * at wrong location.\r
  */\r
 #define MEMHANDLERS_NEED_PC       0\r
+#define MEMHANDLERS_NEED_PREV_PC  0\r
 #define MEMHANDLERS_NEED_FLAGS    0\r
 #define MEMHANDLERS_NEED_CYCLES   1\r
 #define MEMHANDLERS_CHANGE_PC     0\r