sysdeps/x86/fpu/test-fenv-x87.c

   1 /* Test x86-specific floating-point environment (bug 16068): x87 part.
   2    Copyright (C) 2015-2022 Free Software Foundation, Inc.
   3    This file is part of the GNU C Library.
   4
   5    The GNU C Library is free software; you can redistribute it and/or
   6    modify it under the terms of the GNU Lesser General Public
   7    License as published by the Free Software Foundation; either
   8    version 2.1 of the License, or (at your option) any later version.
   9
  10    The GNU C Library is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13    Lesser General Public License for more details.
  14
  15    You should have received a copy of the GNU Lesser General Public
  16    License along with the GNU C Library; if not, see
  17    <https://www.gnu.org/licenses/>.  */
  18
  19 #include <fenv.h>
  20 #include <float.h>
  21 #include <fpu_control.h>
  22 #include <stdint.h>
  23 #include <stdio.h>
  24
  25 static uint16_t
  26 get_x87_cw (void)
  27 {
  28   fpu_control_t cw;
  29   _FPU_GETCW (cw);
  30   return cw;
  31 }
  32
  33 static void
  34 set_x87_cw (uint16_t val)
  35 {
  36   fpu_control_t cw = val;
  37   _FPU_SETCW (cw);
  38 }
  39
  40 static void
  41 set_x87_cw_bits (uint16_t mask, uint16_t bits)
  42 {
  43   uint16_t cw = get_x87_cw ();
  44   cw = (cw & ~mask) | bits;
  45   set_x87_cw (cw);
  46 }
  47
  48 static int
  49 test_x87_cw_bits (const char *test, uint16_t mask, uint16_t bits)
  50 {
  51   uint16_t cw = get_x87_cw ();
  52   printf ("Testing %s: cw = %x\n", test, cw);
  53   if ((cw & mask) == bits)
  54     {
  55       printf ("PASS: %s\n", test);
  56       return 0;
  57     }
  58   else
  59     {
  60       printf ("FAIL: %s\n", test);
  61       return 1;
  62     }
  63 }
  64
  65 static uint16_t
  66 get_x87_sw (void)
  67 {
  68   uint16_t temp;
  69   __asm__ __volatile__ ("fnstsw %0" : "=a" (temp));
  70   return temp;
  71 }
  72
  73 static void
  74 set_x87_sw_bits (uint16_t mask, uint16_t bits)
  75 {
  76   fenv_t temp;
  77   __asm__ __volatile__ ("fnstenv %0" : "=m" (temp));
  78   temp.__status_word = (temp.__status_word & ~mask) | bits;
  79   __asm__ __volatile__ ("fldenv %0" : : "m" (temp));
  80 }
  81
  82 static int
  83 test_x87_sw_bits (const char *test, uint16_t mask, uint16_t bits)
  84 {
  85   uint16_t sw = get_x87_sw ();
  86   printf ("Testing %s: sw = %x\n", test, sw);
  87   if ((sw & mask) == bits)
  88     {
  89       printf ("PASS: %s\n", test);
  90       return 0;
  91     }
  92   else
  93     {
  94       printf ("FAIL: %s\n", test);
  95       return 1;
  96     }
  97 }
  98
  99 #define X87_CW_PREC_MASK _FPU_EXTENDED
 100
 101 static int
 102 do_test (void)
 103 {
 104   int result = 0;
 105   fenv_t env1, env2;
 106   /* Test precision mask.  */
 107   fegetenv (&env1);
 108   set_x87_cw_bits (X87_CW_PREC_MASK, _FPU_SINGLE);
 109   fegetenv (&env2);
 110   fesetenv (&env1);
 111   result |= test_x87_cw_bits ("fesetenv precision restoration",
 112                               X87_CW_PREC_MASK, _FPU_EXTENDED);
 113   set_x87_cw_bits (X87_CW_PREC_MASK, _FPU_EXTENDED);
 114   fesetenv (&env2);
 115   result |= test_x87_cw_bits ("fesetenv precision restoration 2",
 116                               X87_CW_PREC_MASK, _FPU_SINGLE);
 117   set_x87_cw_bits (X87_CW_PREC_MASK, _FPU_DOUBLE);
 118   fesetenv (FE_NOMASK_ENV);
 119   result |= test_x87_cw_bits ("fesetenv (FE_NOMASK_ENV) precision restoration",
 120                               X87_CW_PREC_MASK, _FPU_EXTENDED);
 121   set_x87_cw_bits (X87_CW_PREC_MASK, _FPU_SINGLE);
 122   fesetenv (FE_DFL_ENV);
 123   result |= test_x87_cw_bits ("fesetenv (FE_DFL_ENV) precision restoration",
 124                               X87_CW_PREC_MASK, _FPU_EXTENDED);
 125   /* Test x87 denormal operand masking.  */
 126   set_x87_cw_bits (_FPU_MASK_DM, 0);
 127   fegetenv (&env2);
 128   fesetenv (&env1);
 129   result |= test_x87_cw_bits ("fesetenv denormal mask restoration",
 130                               _FPU_MASK_DM, _FPU_MASK_DM);
 131   set_x87_cw_bits (_FPU_MASK_DM, _FPU_MASK_DM);
 132   fesetenv (&env2);
 133   result |= test_x87_cw_bits ("fesetenv denormal mask restoration 2",
 134                               _FPU_MASK_DM, 0);
 135   set_x87_cw_bits (_FPU_MASK_DM, 0);
 136   /* Presume FE_NOMASK_ENV should leave the "denormal operand"
 137      exception masked, as not a standard exception.  */
 138   fesetenv (FE_NOMASK_ENV);
 139   result |= test_x87_cw_bits ("fesetenv (FE_NOMASK_ENV) denormal mask "
 140                               "restoration",
 141                               _FPU_MASK_DM, _FPU_MASK_DM);
 142   set_x87_cw_bits (_FPU_MASK_DM, 0);
 143   fesetenv (FE_DFL_ENV);
 144   result |= test_x87_cw_bits ("fesetenv (FE_DFL_ENV) denormal mask "
 145                               "restoration",
 146                               _FPU_MASK_DM, _FPU_MASK_DM);
 147   /* Test x87 denormal operand exception.  */
 148   set_x87_sw_bits (__FE_DENORM, __FE_DENORM);
 149   fegetenv (&env2);
 150   fesetenv (&env1);
 151   result |= test_x87_sw_bits ("fesetenv denormal exception restoration",
 152                               __FE_DENORM, 0);
 153   set_x87_sw_bits (__FE_DENORM, 0);
 154   fesetenv (&env2);
 155   result |= test_x87_sw_bits ("fesetenv denormal exception restoration 2",
 156                               __FE_DENORM, __FE_DENORM);
 157   set_x87_sw_bits (__FE_DENORM, __FE_DENORM);
 158   fesetenv (FE_NOMASK_ENV);
 159   result |= test_x87_sw_bits ("fesetenv (FE_NOMASK_ENV) exception restoration",
 160                               __FE_DENORM, 0);
 161   set_x87_sw_bits (__FE_DENORM, __FE_DENORM);
 162   fesetenv (FE_DFL_ENV);
 163   result |= test_x87_sw_bits ("fesetenv (FE_DFL_ENV) exception restoration",
 164                               __FE_DENORM, 0);
 165   return result;
 166 }
 167
 168 #define TEST_FUNCTION do_test ()
 169 #include <test-skeleton.c>