sysdeps/mips/tst-mode-switch-3.c

   1 /* Copyright (C) 2014-2015 Free Software Foundation, Inc.
   2    This file is part of the GNU C Library.
   3
   4    The GNU C Library is free software; you can redistribute it and/or
   5    modify it under the terms of the GNU Lesser General Public
   6    License as published by the Free Software Foundation; either
   7    version 2.1 of the License, or (at your option) any later version.
   8
   9    The GNU C Library 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 GNU
  12    Lesser General Public License for more details.
  13
  14    You should have received a copy of the GNU Lesser General Public
  15    License along with the GNU C Library; if not, see
  16    <http://www.gnu.org/licenses/>.  */
  17
  18 #include <errno.h>
  19 #include <stdio.h>
  20 #include <stdlib.h>
  21 #include <string.h>
  22 #include <unistd.h>
  23 #include <setjmp.h>
  24 #include <sys/prctl.h>
  25
  26 #if __mips_fpr != 0 || _MIPS_SPFPSET != 16
  27 # error This test requires -mfpxx -mno-odd-spreg
  28 #endif
  29
  30 /* This test verifies that mode changes between a setjmp and longjmp do
  31    not corrupt the state of callee-saved registers.  */
  32
  33 static int mode[6] =
  34   {
  35     0,
  36     PR_FP_MODE_FR,
  37     PR_FP_MODE_FR | PR_FP_MODE_FRE,
  38     PR_FP_MODE_FR,
  39     0,
  40     PR_FP_MODE_FR | PR_FP_MODE_FRE
  41   };
  42 static jmp_buf env;
  43 float check1 = 2.0;
  44 double check2 = 3.0;
  45
  46 int
  47 main (void)
  48 {
  49   int i;
  50   int result = 0;
  51
  52   for (i = 0 ; i < 7 ; i++)
  53     {
  54       int retval;
  55       register float test1 __asm ("$f20");
  56       register double test2 __asm ("$f22");
  57
  58       /* Hide what we are doing to $f20 and $f22 from the compiler.  */
  59       __asm __volatile ("l.s %0,%2\n"
  60                         "l.d %1,%3\n"
  61                         : "=f" (test1), "=f" (test2)
  62                         : "m" (check1), "m" (check2));
  63
  64       retval = setjmp (env);
  65
  66       /* Make sure the compiler knows we want to access the variables
  67          via the named registers again.  */
  68       __asm __volatile ("" : : "f" (test1), "f" (test2));
  69
  70       if (test1 != check1 || test2 != check2)
  71         {
  72           printf ("Corrupt register detected: $20 %f = %f, $22 %f = %f\n",
  73                   test1, check1, test2, check2);
  74           result = 1;
  75         }
  76
  77       if (retval == 0)
  78         {
  79           if (prctl (PR_SET_FP_MODE, mode[i % 6]) != 0
  80               && errno != ENOTSUP)
  81             {
  82               printf ("prctl PR_SET_FP_MODE failed: %m");
  83               exit (1);
  84             }
  85           longjmp (env, 0);
  86         }
  87     }
  88
  89   return result;
  90 }