68k, fix idle loop detection crash on 64 bit platforms

diff --git a/pico/sek.c b/pico/sek.c
index bd8f70f..ccbddb8 100644 (file)
--- a/pico/sek.c
+++ b/pico/sek.c
@@ -398,7 +398,7 @@ int SekRegisterIdlePatch(unsigned int pc, int oldop, int newop, void *ctx)
 \r
   // XXX: probably shouldn't patch RAM too\r
   v = m68k_read16_map[pc >> M68K_MEM_SHIFT];\r
-  if (!(v & 0x80000000))\r
+  if (~v & ~((uptr)-1LL >> 1)) // MSB clear?\r
     target = (u16 *)((v << 1) + pc);\r
   else {\r
     if (++idledet_bads > 128)\r