LXR qemu/tests/tcg/hexagon/overflow.c

   1/*
   2 *  Copyright(c) 2021 Qualcomm Innovation Center, Inc. All Rights Reserved.
   3 *
   4 *  This program is free software; you can redistribute it and/or modify
   5 *  it under the terms of the GNU General Public License as published by
   6 *  the Free Software Foundation; either version 2 of the License, or
   7 *  (at your option) any later version.
   8 *
   9 *  This program is distributed in the hope that it will be useful,
  10 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  11 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12 *  GNU General Public License for more details.
  13 *
  14 *  You should have received a copy of the GNU General Public License
  15 *  along with this program; if not, see <http://www.gnu.org/licenses/>.
  16 */
  17
  18#include <stdlib.h>
  19#include <stdio.h>
  20#include <unistd.h>
  21#include <sys/types.h>
  22#include <fcntl.h>
  23#include <setjmp.h>
  24#include <signal.h>
  25
  26
  27int err;
  28
  29static void __check(const char *filename, int line, int x, int expect)
  30{
  31    if (x != expect) {
  32        printf("ERROR %s:%d - %d != %d\n",
  33               filename, line, x, expect);
  34        err++;
  35    }
  36}
  37
  38#define check(x, expect) __check(__FILE__, __LINE__, (x), (expect))
  39
  40static int satub(int src, int *p, int *ovf_result)
  41{
  42    int result;
  43    int usr;
  44
  45    /*
  46     * This instruction can set bit 0 (OVF/overflow) in usr
  47     * Clear the bit first, then return that bit to the caller
  48     *
  49     * We also store the src into *p in the same packet, so we
  50     * can ensure the overflow doesn't get set when an exception
  51     * is generated.
  52     */
  53    asm volatile("r2 = usr\n\t"
  54                 "r2 = clrbit(r2, #0)\n\t"        /* clear overflow bit */
  55                 "usr = r2\n\t"
  56                 "{\n\t"
  57                 "    %0 = satub(%2)\n\t"
  58                 "    memw(%3) = %2\n\t"
  59                 "}\n\t"
  60                 "%1 = usr\n\t"
  61                 : "=r"(result), "=r"(usr)
  62                 : "r"(src), "r"(p)
  63                 : "r2", "usr", "memory");
  64  *ovf_result = (usr & 1);
  65  return result;
  66}
  67
  68int read_usr_overflow(void)
  69{
  70    int result;
  71    asm volatile("%0 = usr\n\t" : "=r"(result));
  72    return result & 1;
  73}
  74
  75
  76jmp_buf jmp_env;
  77int usr_overflow;
  78
  79static void sig_segv(int sig, siginfo_t *info, void *puc)
  80{
  81    usr_overflow = read_usr_overflow();
  82    longjmp(jmp_env, 1);
  83}
  84
  85int main()
  86{
  87    struct sigaction act;
  88    int ovf;
  89
  90    /* SIGSEGV test */
  91    act.sa_sigaction = sig_segv;
  92    sigemptyset(&act.sa_mask);
  93    act.sa_flags = SA_SIGINFO;
  94    sigaction(SIGSEGV, &act, NULL);
  95    if (setjmp(jmp_env) == 0) {
  96        satub(300, 0, &ovf);
  97    }
  98
  99    act.sa_handler = SIG_DFL;
 100    sigemptyset(&act.sa_mask);
 101    act.sa_flags = 0;
 102
 103    check(usr_overflow, 0);
 104
 105    puts(err ? "FAIL" : "PASS");
 106    return err ? EXIT_FAILURE : EXIT_SUCCESS;
 107}
 108