/*      $OpenBSD: fdump.c,v 1.2 2021/12/13 16:56:49 deraadt Exp $       */
/*
 * Copyright (c) 2018 Alexander Bluhm <bluhm@openbsd.org>
 *
 * Permission to use, copy, modify, and distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */

#include <sys/types.h>

#include <err.h>
#include <fenv.h>
#include <stdio.h>
#include <unistd.h>

#define nitems(_a)     (sizeof((_a)) / sizeof((_a)[0]))

int
main(int argc, char *argv[])
{
        struct {
                fenv_t  fenv;
                /* Try to read more and check env length. */
                char    pad[1];
        } buf;
        fenv_t *fenv = &buf.fenv;
        ssize_t len;
        size_t i;

        len = read(0, &buf, sizeof(buf));
        if (len < 0 )
                err(1, "read");
        if (len != sizeof(fenv_t))
                errx(1, "read len %zd is not size %zu", len, sizeof(fenv_t));

        printf("control\t%08x\n", fenv->__x87.__control);
        printf("status\t%08x\n", fenv->__x87.__status);
        printf("tag\t%08x\n", fenv->__x87.__tag);
        for (i = 0; i < nitems(fenv->__x87.__others); i++) {
                printf("others[%zu]\t%08x\n", i, fenv->__x87.__others[i]);
        }
        printf("mxcsr\t%08x\n", fenv->__mxcsr);

        return 0;
}