The warning above pointed me to some strange code. I guess this was
originally indented:

Signed-off-by: Jan Kiszka <jan.kiszka@web.de>

Index: qemu/target-sh4/op.c
===================================================================
--- qemu.orig/target-sh4/op.c
+++ qemu/target-sh4/op.c
@@ -594,8 +594,8 @@ void OPPROTO op_shlr16_Rn(void)

 void OPPROTO op_tasb_rN(void)
 {
-    cond_t(*(int8_t *) env->gregs[PARAM1] == 0);
-    *(int8_t *) env->gregs[PARAM1] |= 0x80;
+    cond_t((env->gregs[PARAM1] & 0xff) == 0);
+    *(int8_t *) &env->gregs[PARAM1] |= 0x80;
     RETURN();
 }