Question

我在QNX中实现了以下代码来处理除以零的异常。

static int st_iThreadID = -1;
static sigjmp_buf fpe_env;
float a = -10, b = 0;
volatile float c = 0;
 /**************************************
 *
 * Signal Handler for Divided by zero exception
 *
 ****************************************/
void SignalHandler(int Signo,siginfo_t* info,void* other)
{
 int iThreadID =  gettid();`enter code here`
printf( " exception caught for thread \t %d Generated Signal is \t %d   \n",iThreadID,Signo);   
siglongjmp(fpe_env, info->si_code);
}

 /**************************************
 *
 * Handler Ends
 *
 ****************************************/


int TestDividedByZero()
{
 /*local variable initialization*/
    int l_iStatus = 0;
    sigset_t set;
    int code ;
    struct sigaction act;   /*Sigaction structure to set the action for Signal*/

/*End local variable initialization*/       

    fp_exception_mask(_FP_EXC_DIVZERO, 1 );   /* Set the exception mask for floating point Exception */


    sigfillset( &act.sa_mask);
    sigdelset(&set,SIGFPE);

    act.sa_flags = SA_SIGINFO;
    act.sa_mask = set;
    act.sa_sigaction =SignalHandler;
    sigaction(SIGFPE, &act, NULL ); /* POSIX: Specify the action associated with a signal SIGFPE */


    code = sigsetjmp(fpe_env, 1);
    if(code == 0)
    {

        c = a / b;   /*Here generates floating point signal SIGFPE and registered handler will get call */
        //  printf("value of d is %d \n",d);
    }
    else
    {
        puts( "Jumped from Signal handler");
        c = 0;  // Set result to default value      
    }
    //puts( "End SIGFPE of Testing ");

    return l_iStatus ;

}

当变量的类型是float或double时，此代码生成SIGFPE，但是当将变量类型更改为int或long时，此代码不会生成SIGFPE。我使用的是gcc编译器，处理器是POWERPC MPC8347，OS是QNX。我也想用整数值测试SIGFPE。早期相同的代码也没有为float生成SIGFPE，但后来我添加了fp_exception_mask（），它工作正常。整数运算有没有这样的掩码？

PowerPC：整数除法不生成SIGFPE

0 个答案: