// SPDX-License-Identifier: GPL-2.0
#undef _GNU_SOURCE
#define _GNU_SOURCE 1
#undef __USE_GNU
#define __USE_GNU 1
#include <unistd.h>
#include <stdlib.h>
#include <string.h>
#include <stdio.h>
#include <signal.h>
#include <sys/types.h>
#include <sys/select.h>
#include <sys/time.h>
#include <sys/wait.h>
#include <fenv.h>

enum {
        CF = 1 << 0,
        PF = 1 << 2,
        ZF = 1 << 6,
        ARITH = CF | PF | ZF,
};

long res_fcomi_pi_1;
long res_fcomi_1_pi;
long res_fcomi_1_1;
long res_fcomi_nan_1;
/* sNaN is s|111 1111 1|1xx xxxx xxxx xxxx xxxx xxxx */
/* qNaN is s|111 1111 1|0xx xxxx xxxx xxxx xxxx xxxx (some x must be nonzero) */
int snan = 0x7fc11111;
int qnan = 0x7f811111;
unsigned short snan1[5];
/* sNaN80 is s|111 1111 1111 1111 |10xx xx...xx (some x must be nonzero) */
unsigned short snan80[5] = { 0x1111, 0x1111, 0x1111, 0x8111, 0x7fff };

int test(long flags)
{
        feclearexcept(FE_DIVBYZERO|FE_INEXACT|FE_INVALID|FE_OVERFLOW|FE_UNDERFLOW);

        asm ("\n"

        "       push    %0""\n"
        "       popf""\n"
        "       fld1""\n"
        "       fldpi""\n"
        "       fcomi   %%st(1), %%st" "\n"
        "       ffree   %%st(0)" "\n"
        "       ffree   %%st(1)" "\n"
        "       pushf""\n"
        "       pop     res_fcomi_1_pi""\n"

        "       push    %0""\n"
        "       popf""\n"
        "       fldpi""\n"
        "       fld1""\n"
        "       fcomi   %%st(1), %%st" "\n"
        "       ffree   %%st(0)" "\n"
        "       ffree   %%st(1)" "\n"
        "       pushf""\n"
        "       pop     res_fcomi_pi_1""\n"

        "       push    %0""\n"
        "       popf""\n"
        "       fld1""\n"
        "       fld1""\n"
        "       fcomi   %%st(1), %%st" "\n"
        "       ffree   %%st(0)" "\n"
        "       ffree   %%st(1)" "\n"
        "       pushf""\n"
        "       pop     res_fcomi_1_1""\n"
        :
        : "r" (flags)
        );
        if ((res_fcomi_1_pi & ARITH) != (0)) {
                printf("[BAD]\tfcomi_1_pi with flags:%lx\n", flags);
                return 1;
        }
        if ((res_fcomi_pi_1 & ARITH) != (CF)) {
                printf("[BAD]\tfcomi_pi_1 with flags:%lx->%lx\n", flags, res_fcomi_pi_1 & ARITH);
                return 1;
        }
        if ((res_fcomi_1_1 & ARITH) != (ZF)) {
                printf("[BAD]\tfcomi_1_1 with flags:%lx\n", flags);
                return 1;
        }
        if (fetestexcept(FE_INVALID) != 0) {
                printf("[BAD]\tFE_INVALID is set in %s\n", __func__);
                return 1;
        }
        return 0;
}

int test_qnan(long flags)
{
        feclearexcept(FE_DIVBYZERO|FE_INEXACT|FE_INVALID|FE_OVERFLOW|FE_UNDERFLOW);

        asm ("\n"
        "       push    %0""\n"
        "       popf""\n"
        "       flds    qnan""\n"
        "       fld1""\n"
        "       fnclex""\n"             // fld of a qnan raised FE_INVALID, clear it
        "       fcomi   %%st(1), %%st" "\n"
        "       ffree   %%st(0)" "\n"
        "       ffree   %%st(1)" "\n"
        "       pushf""\n"
        "       pop     res_fcomi_nan_1""\n"
        :
        : "r" (flags)
        );
        if ((res_fcomi_nan_1 & ARITH) != (ZF|CF|PF)) {
                printf("[BAD]\tfcomi_qnan_1 with flags:%lx\n", flags);
                return 1;
        }
        if (fetestexcept(FE_INVALID) != FE_INVALID) {
                printf("[BAD]\tFE_INVALID is not set in %s\n", __func__);
                return 1;
        }
        return 0;
}

int testu_qnan(long flags)
{
        feclearexcept(FE_DIVBYZERO|FE_INEXACT|FE_INVALID|FE_OVERFLOW|FE_UNDERFLOW);

        asm ("\n"
        "       push    %0""\n"
        "       popf""\n"
        "       flds    qnan""\n"
        "       fld1""\n"
        "       fnclex""\n"             // fld of a qnan raised FE_INVALID, clear it
        "       fucomi  %%st(1), %%st" "\n"
        "       ffree   %%st(0)" "\n"
        "       ffree   %%st(1)" "\n"
        "       pushf""\n"
        "       pop     res_fcomi_nan_1""\n"
        :
        : "r" (flags)
        );
        if ((res_fcomi_nan_1 & ARITH) != (ZF|CF|PF)) {
                printf("[BAD]\tfcomi_qnan_1 with flags:%lx\n", flags);
                return 1;
        }
        if (fetestexcept(FE_INVALID) != 0) {
                printf("[BAD]\tFE_INVALID is set in %s\n", __func__);
                return 1;
        }
        return 0;
}

int testu_snan(long flags)
{
        feclearexcept(FE_DIVBYZERO|FE_INEXACT|FE_INVALID|FE_OVERFLOW|FE_UNDERFLOW);

        asm ("\n"
        "       push    %0""\n"
        "       popf""\n"
//      "       flds    snan""\n"       // WRONG, this will convert 32-bit fp snan to a *qnan* in 80-bit fp register!
//      "       fstpt   snan1""\n"      // if uncommented, it prints "snan1:7fff c111 1100 0000 0000" - c111, not 8111!
//      "       fnclex""\n"             // flds of a snan raised FE_INVALID, clear it
        "       fldt    snan80""\n"     // fldt never raise FE_INVALID
        "       fld1""\n"
        "       fucomi  %%st(1), %%st" "\n"
        "       ffree   %%st(0)" "\n"
        "       ffree   %%st(1)" "\n"
        "       pushf""\n"
        "       pop     res_fcomi_nan_1""\n"
        :
        : "r" (flags)
        );
        if ((res_fcomi_nan_1 & ARITH) != (ZF|CF|PF)) {
                printf("[BAD]\tfcomi_qnan_1 with flags:%lx\n", flags);
                return 1;
        }
//      printf("snan:%x snan1:%04x %04x %04x %04x %04x\n", snan, snan1[4], snan1[3], snan1[2], snan1[1], snan1[0]);
        if (fetestexcept(FE_INVALID) != FE_INVALID) {
                printf("[BAD]\tFE_INVALID is not set in %s\n", __func__);
                return 1;
        }
        return 0;
}

int testp(long flags)
{
        feclearexcept(FE_DIVBYZERO|FE_INEXACT|FE_INVALID|FE_OVERFLOW|FE_UNDERFLOW);

        asm ("\n"

        "       push    %0""\n"
        "       popf""\n"
        "       fld1""\n"
        "       fldpi""\n"
        "       fcomip  %%st(1), %%st" "\n"
        "       ffree   %%st(0)" "\n"
        "       pushf""\n"
        "       pop     res_fcomi_1_pi""\n"

        "       push    %0""\n"
        "       popf""\n"
        "       fldpi""\n"
        "       fld1""\n"
        "       fcomip  %%st(1), %%st" "\n"
        "       ffree   %%st(0)" "\n"
        "       pushf""\n"
        "       pop     res_fcomi_pi_1""\n"

        "       push    %0""\n"
        "       popf""\n"
        "       fld1""\n"
        "       fld1""\n"
        "       fcomip  %%st(1), %%st" "\n"
        "       ffree   %%st(0)" "\n"
        "       pushf""\n"
        "       pop     res_fcomi_1_1""\n"
        :
        : "r" (flags)
        );
        if ((res_fcomi_1_pi & ARITH) != (0)) {
                printf("[BAD]\tfcomi_1_pi with flags:%lx\n", flags);
                return 1;
        }
        if ((res_fcomi_pi_1 & ARITH) != (CF)) {
                printf("[BAD]\tfcomi_pi_1 with flags:%lx->%lx\n", flags, res_fcomi_pi_1 & ARITH);
                return 1;
        }
        if ((res_fcomi_1_1 & ARITH) != (ZF)) {
                printf("[BAD]\tfcomi_1_1 with flags:%lx\n", flags);
                return 1;
        }
        if (fetestexcept(FE_INVALID) != 0) {
                printf("[BAD]\tFE_INVALID is set in %s\n", __func__);
                return 1;
        }
        return 0;
}

int testp_qnan(long flags)
{
        feclearexcept(FE_DIVBYZERO|FE_INEXACT|FE_INVALID|FE_OVERFLOW|FE_UNDERFLOW);

        asm ("\n"
        "       push    %0""\n"
        "       popf""\n"
        "       flds    qnan""\n"
        "       fld1""\n"
        "       fnclex""\n"             // fld of a qnan raised FE_INVALID, clear it
        "       fcomip  %%st(1), %%st" "\n"
        "       ffree   %%st(0)" "\n"
        "       pushf""\n"
        "       pop     res_fcomi_nan_1""\n"
        :
        : "r" (flags)
        );
        if ((res_fcomi_nan_1 & ARITH) != (ZF|CF|PF)) {
                printf("[BAD]\tfcomi_qnan_1 with flags:%lx\n", flags);
                return 1;
        }
        if (fetestexcept(FE_INVALID) != FE_INVALID) {
                printf("[BAD]\tFE_INVALID is not set in %s\n", __func__);
                return 1;
        }
        return 0;
}

int testup_qnan(long flags)
{
        feclearexcept(FE_DIVBYZERO|FE_INEXACT|FE_INVALID|FE_OVERFLOW|FE_UNDERFLOW);

        asm ("\n"
        "       push    %0""\n"
        "       popf""\n"
        "       flds    qnan""\n"
        "       fld1""\n"
        "       fnclex""\n"             // fld of a qnan raised FE_INVALID, clear it
        "       fucomip %%st(1), %%st" "\n"
        "       ffree   %%st(0)" "\n"
        "       pushf""\n"
        "       pop     res_fcomi_nan_1""\n"
        :
        : "r" (flags)
        );
        if ((res_fcomi_nan_1 & ARITH) != (ZF|CF|PF)) {
                printf("[BAD]\tfcomi_qnan_1 with flags:%lx\n", flags);
                return 1;
        }
        if (fetestexcept(FE_INVALID) != 0) {
                printf("[BAD]\tFE_INVALID is set in %s\n", __func__);
                return 1;
        }
        return 0;
}

void sighandler(int sig)
{
        printf("[FAIL]\tGot signal %d, exiting\n", sig);
        exit(1);
}

int main(int argc, char **argv, char **envp)
{
        int err = 0;

        /* SIGILL triggers on 32-bit kernels w/o fcomi emulation
         * when run with "no387 nofxsr". Other signals are caught
         * just in case.
         */
        signal(SIGILL, sighandler);
        signal(SIGFPE, sighandler);
        signal(SIGSEGV, sighandler);

        printf("[RUN]\tTesting f[u]comi[p] instructions\n");
        err |= test(0);
        err |= test_qnan(0);
        err |= testu_qnan(0);
        err |= testu_snan(0);
        err |= test(CF|ZF|PF);
        err |= test_qnan(CF|ZF|PF);
        err |= testu_qnan(CF|ZF|PF);
        err |= testu_snan(CF|ZF|PF);
        err |= testp(0);
        err |= testp_qnan(0);
        err |= testup_qnan(0);
        err |= testp(CF|ZF|PF);
        err |= testp_qnan(CF|ZF|PF);
        err |= testup_qnan(CF|ZF|PF);
        if (!err)
                printf("[OK]\tf[u]comi[p]\n");
        else
                printf("[FAIL]\tf[u]comi[p] errors: %d\n", err);

        return err;
}