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1// SPDX-License-Identifier: GPL-2.0-or-later2/*3 * Copyright IBM Corp. 20204 *5 * This test attempts to cause a FP denormal exception on POWER8 CPUs. Unfortunately6 * if the denormal handler is not configured or working properly, this can cause a bad7 * crash in kernel mode when the kernel tries to save FP registers when the process8 * exits.9 */10 11#include <stdio.h>12#include <string.h>13 14#include "utils.h"15 16static int test_denormal_fpu(void)17{18 unsigned int m32;19 unsigned long m64;20 volatile float f;21 volatile double d;22 23 /* try to induce lfs <denormal> ; stfd */24 25 m32 = 0x00715fcf; /* random denormal */26 memcpy((float *)&f, &m32, sizeof(f));27 d = f;28 memcpy(&m64, (double *)&d, sizeof(d));29 30 FAIL_IF((long)(m64 != 0x380c57f3c0000000)); /* renormalised value */31 32 return 0;33}34 35int main(int argc, char *argv[])36{37 return test_harness(test_denormal_fpu, "fpu_denormal");38}39