target/rx: Update flow of interrupt execution for target rx

do_interrupt function is call directly from CPU exception so we
need to add condition to check for CPU exception in case of
hardware interrupt is preempted to prevent unexpect behavior

Signed-off-by: Duy Nguyen <[email protected]>

Author: duynguyenxa

target/rx/helper.c

@@ -48,16 +48,16 @@ void rx_cpu_do_interrupt(CPUState *cs)
     uint32_t save_psw;
 
     env->in_sleep = 0;
-
     if (env->psw_u) {
         env->usp = env->regs[0];
     } else {
         env->isp = env->regs[0];
     }
     save_psw = rx_cpu_pack_psw(env);
     env->psw_pm = env->psw_i = env->psw_u = 0;
+    int32_t vec = cs->exception_index;
 
-    if (do_irq) {
+    if (do_irq && vec < 0) {
         if (do_irq & CPU_INTERRUPT_FIR) {
             env->bpc = env->pc;
             env->bpsw = save_psw;
@@ -79,7 +79,6 @@ void rx_cpu_do_interrupt(CPUState *cs)
                           "interrupt 0x%02x raised\n", env->ack_irq);
         }
     } else {
-        uint32_t vec = cs->exception_index;
         const char *expname = "unknown exception";
 
         env->isp -= 4;