LXR qemu/tests/tcg/hexagon/mem_noshuf

   1/*
   2 *  Copyright(c) 2022 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/*
  19 * Test the VLIW semantics of exceptions with mem_noshuf
  20 *
  21 * When a packet has the :mem_noshuf attribute, the semantics dictate
  22 * That the load will get the data from the store if the addresses overlap.
  23 * To accomplish this, we perform the store first.  However, we have to
  24 * handle the case where the store raises an exception.  In that case, the
  25 * store should not alter the machine state.
  26 *
  27 * We test this with a mem_noshuf packet with a store to a global variable,
  28 * "should_not_change" and a load from NULL.  After the SIGSEGV is caught,
  29 * we check * that the "should_not_change" value is the same.
  30 *
  31 * We also check that a predicated load where the predicate is false doesn't
  32 * raise an exception and allows the store to happen.
  33 */
  34
  35#include <stdlib.h>
  36#include <stdio.h>
  37#include <unistd.h>
  38#include <sys/types.h>
  39#include <fcntl.h>
  40#include <setjmp.h>
  41#include <signal.h>
  42
  43int err;
  44int segv_caught;
  45
  46#define SHOULD_NOT_CHANGE_VAL        5
  47int should_not_change = SHOULD_NOT_CHANGE_VAL;
  48
  49#define OK_TO_CHANGE_VAL        13
  50int ok_to_change = OK_TO_CHANGE_VAL;
  51
  52static void __check(const char *filename, int line, int x, int expect)
  53{
  54    if (x != expect) {
  55        printf("ERROR %s:%d - %d != %d\n",
  56               filename, line, x, expect);
  57        err++;
  58    }
  59}
  60
  61#define check(x, expect) __check(__FILE__, __LINE__, (x), (expect))
  62
  63static void __chk_error(const char *filename, int line, int ret)
  64{
  65    if (ret < 0) {
  66        printf("ERROR %s:%d - %d\n", filename, line, ret);
  67        err++;
  68    }
  69}
  70
  71#define chk_error(ret) __chk_error(__FILE__, __LINE__, (ret))
  72
  73jmp_buf jmp_env;
  74
  75static void sig_segv(int sig, siginfo_t *info, void *puc)
  76{
  77    check(sig, SIGSEGV);
  78    segv_caught = 1;
  79    longjmp(jmp_env, 1);
  80}
  81
  82int main()
  83{
  84    struct sigaction act;
  85    int dummy32;
  86    long long dummy64;
  87    void *p;
  88
  89    /* SIGSEGV test */
  90    act.sa_sigaction = sig_segv;
  91    sigemptyset(&act.sa_mask);
  92    act.sa_flags = SA_SIGINFO;
  93    chk_error(sigaction(SIGSEGV, &act, NULL));
  94    if (setjmp(jmp_env) == 0) {
  95        asm volatile("r18 = ##should_not_change\n\t"
  96                     "r19 = #0\n\t"
  97                     "{\n\t"
  98                     "    memw(r18) = #7\n\t"
  99                     "    %0 = memw(r19)\n\t"
 100                     "}:mem_noshuf\n\t"
 101                      : "=r"(dummy32) : : "r18", "r19", "memory");
 102    }
 103
 104    act.sa_handler = SIG_DFL;
 105    sigemptyset(&act.sa_mask);
 106    act.sa_flags = 0;
 107    chk_error(sigaction(SIGSEGV, &act, NULL));
 108
 109    check(segv_caught, 1);
 110    check(should_not_change, SHOULD_NOT_CHANGE_VAL);
 111
 112    /*
 113     * Check that a predicated load where the predicate is false doesn't
 114     * raise an exception and allows the store to happen.
 115     */
 116    asm volatile("r18 = ##ok_to_change\n\t"
 117                 "r19 = #0\n\t"
 118                 "p0 = cmp.gt(r0, r0)\n\t"
 119                 "{\n\t"
 120                 "    memw(r18) = #7\n\t"
 121                 "    if (p0) %0 = memw(r19)\n\t"
 122                 "}:mem_noshuf\n\t"
 123                  : "=r"(dummy32) : : "r18", "r19", "p0", "memory");
 124
 125    check(ok_to_change, 7);
 126
 127    /*
 128     * Also check that the post-increment doesn't happen when the
 129     * predicate is false.
 130     */
 131    ok_to_change = OK_TO_CHANGE_VAL;
 132    p = NULL;
 133    asm volatile("r18 = ##ok_to_change\n\t"
 134                 "p0 = cmp.gt(r0, r0)\n\t"
 135                 "{\n\t"
 136                 "    memw(r18) = #9\n\t"
 137                 "    if (p0) %1 = memd(%0 ++ #8)\n\t"
 138                 "}:mem_noshuf\n\t"
 139                  : "+r"(p), "=r"(dummy64) : : "r18", "p0", "memory");
 140
 141    check(ok_to_change, 9);
 142    check((int)p, (int)NULL);
 143
 144    puts(err ? "FAIL" : "PASS");
 145    return err ? EXIT_FAILURE : EXIT_SUCCESS;
 146}
 147