// SPDX-License-Identifier: GPL-2.0-or-later
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/*
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* Copyright IBM Corp. 2020
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*
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* This test attempts to cause a FP denormal exception on POWER8 CPUs. Unfortunately
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* if the denormal handler is not configured or working properly, this can cause a bad
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* crash in kernel mode when the kernel tries to save FP registers when the process
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* exits.
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*/
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#include <stdio.h>
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#include <string.h>
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#include "utils.h"
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static int test_denormal_fpu(void)
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{
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unsigned int m32;
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unsigned long m64;
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volatile float f;
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volatile double d;
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/* try to induce lfs <denormal> ; stfd */
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m32 = 0x00715fcf; /* random denormal */
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memcpy((float *)&f, &m32, sizeof(f));
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d = f;
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memcpy(&m64, (double *)&d, sizeof(d));
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FAIL_IF((long)(m64 != 0x380c57f3c0000000)); /* renormalised value */
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return 0;
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}
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int main(int argc, char *argv[])
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{
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return test_harness(test_denormal_fpu, "fpu_denormal");
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}
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