/* Copyright (C) 2001-2023 Free Software Foundation, Inc.
This file is part of the GNU C Library.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, see
. */
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
static ucontext_t ctx[3];
volatile int global;
static int back_in_main;
volatile static ElfW(auxv_t) *auxv = NULL;
ElfW(Addr) query_auxv(int type)
{
FILE *auxv_f;
ElfW(auxv_t) auxv_struct;
ElfW(auxv_t) *auxv_temp;
int i = 0;
/* if the /proc/self/auxv file has not been manually copied into the heap
yet, then do it */
if(auxv == NULL)
{
auxv_f = fopen("/proc/self/auxv", "r");
if(auxv_f == 0)
{
perror("Error opening file for reading");
return 0;
}
auxv = xmalloc (getpagesize ());
do
{
xfread (&auxv_struct, sizeof (ElfW(auxv_t)), 1, auxv_f);
auxv[i] = auxv_struct;
i++;
} while(auxv_struct.a_type != AT_NULL);
}
auxv_temp = (ElfW(auxv_t) *)auxv;
i = 0;
do
{
if(auxv_temp[i].a_type == type)
{
return auxv_temp[i].a_un.a_val;
}
i++;
} while (auxv_temp[i].a_type != AT_NULL);
return 0;
}
typedef unsigned int di_fpscr_t __attribute__ ((__mode__ (__DI__)));
typedef unsigned int si_fpscr_t __attribute__ ((__mode__ (__SI__)));
#define _FPSCR_RESERVED 0xfffffff8ffffff04ULL
#define _FPSCR_TEST0_DRN 0x0000000400000000ULL
#define _FPSCR_TEST0_RN 0x0000000000000003ULL
#define _FPSCR_TEST1_DRN 0x0000000300000000ULL
#define _FPSCR_TEST1_RN 0x0000000000000002ULL
/* Macros for accessing the hardware control word on Power6[x]. */
#define _GET_DI_FPSCR(__fpscr) \
({union { double d; di_fpscr_t fpscr; } u; \
u.d = __builtin_mffs (); \
(__fpscr) = u.fpscr; \
u.fpscr; \
})
/* We make sure to zero fp after we use it in order to prevent stale data
in an fp register from making a test-case pass erroneously. */
# define _SET_DI_FPSCR(__fpscr) \
{ union { double d; di_fpscr_t fpscr; } u; \
register double fr; \
u.fpscr = __fpscr; \
fr = u.d; \
/* Set the entire 64-bit FPSCR. */ \
__asm__ (".machine push; " \
".machine \"power6\"; " \
"mtfsf 255,%0,1,0; " \
".machine pop" : : "f" (fr)); \
fr = 0.0; \
}
# define _GET_SI_FPSCR(__fpscr) \
({union { double d; di_fpscr_t fpscr; } u; \
u.d = __builtin_mffs (); \
(__fpscr) = (si_fpscr_t) u.fpscr; \
(si_fpscr_t) u.fpscr; \
})
/* We make sure to zero fp after we use it in order to prevent stale data
in an fp register from making a test-case pass erroneously. */
# define _SET_SI_FPSCR(__fpscr) \
{ union { double d; di_fpscr_t fpscr; } u; \
register double fr; \
/* More-or-less arbitrary; this is a QNaN. */ \
u.fpscr = 0xfff80000ULL << 32; \
u.fpscr |= __fpscr & 0xffffffffULL; \
fr = u.d; \
__builtin_mtfsf (255, fr); \
fr = 0.0; \
}
void prime_special_regs(int which)
{
ElfW(Addr) a_val;
di_fpscr_t di_fpscr __attribute__ ((__aligned__(8)));
a_val = query_auxv(AT_HWCAP);
if(a_val == -1)
{
puts ("querying the auxv for the hwcap failed");
_exit (1);
}
/* Indicates a 64-bit FPSCR. */
if (a_val & PPC_FEATURE_HAS_DFP)
{
_GET_DI_FPSCR(di_fpscr);
/* Overwrite the existing DRN and RN if there is one. */
if (which == 0)
di_fpscr = ((di_fpscr & _FPSCR_RESERVED) | (_FPSCR_TEST0_DRN | _FPSCR_TEST0_RN));
else
di_fpscr = ((di_fpscr & _FPSCR_RESERVED) | (_FPSCR_TEST1_DRN | _FPSCR_TEST1_RN));
puts ("Priming 64-bit FPSCR with:");
printf("0x%.16llx\n",(unsigned long long int)di_fpscr);
_SET_DI_FPSCR(di_fpscr);
}
else
{
puts ("32-bit FPSCR found and will be tested.");
_GET_SI_FPSCR(di_fpscr);
/* Overwrite the existing RN if there is one. */
if (which == 0)
di_fpscr = ((di_fpscr & _FPSCR_RESERVED) | (_FPSCR_TEST0_RN));
else
di_fpscr = ((di_fpscr & _FPSCR_RESERVED) | (_FPSCR_TEST1_RN));
puts ("Priming 32-bit FPSCR with:");
printf("0x%.8lx\n",(unsigned long int) di_fpscr);
_SET_SI_FPSCR(di_fpscr);
}
}
void clear_special_regs(void)
{
ElfW(Addr) a_val;
di_fpscr_t di_fpscr __attribute__ ((__aligned__(8)));
union {
double d;
unsigned long long int lli;
unsigned int li[2];
} dlli;
a_val = query_auxv(AT_HWCAP);
if(a_val == -1)
{
puts ("querying the auxv for the hwcap failed");
_exit (1);
}
#if __WORDSIZE == 32
dlli.d = ctx[0].uc_mcontext.uc_regs->fpregs.fpscr;
#else
dlli.d = ctx[0].uc_mcontext.fp_regs[32];
#endif
puts("The FPSCR value saved in the ucontext_t is:");
/* Indicates a 64-bit FPSCR. */
if (a_val & PPC_FEATURE_HAS_DFP)
{
printf("0x%.16llx\n",dlli.lli);
di_fpscr = 0x0;
puts ("Clearing the 64-bit FPSCR to:");
printf("0x%.16llx\n",(unsigned long long int) di_fpscr);
_SET_DI_FPSCR(di_fpscr);
}
else
{
printf("0x%.8x\n",(unsigned int) dlli.li[1]);
di_fpscr = 0x0;
puts ("Clearing the 32-bit FPSCR to:");
printf("0x%.8lx\n",(unsigned long int) di_fpscr);
_SET_SI_FPSCR(di_fpscr);
}
}
void test_special_regs(int which)
{
ElfW(Addr) a_val;
unsigned long long int test;
di_fpscr_t di_fpscr __attribute__ ((__aligned__(8)));
a_val = query_auxv(AT_HWCAP);
if(a_val == -1)
{
puts ("querying the auxv for the hwcap failed");
_exit (2);
}
/* Indicates a 64-bit FPSCR. */
if (a_val & PPC_FEATURE_HAS_DFP)
{
_GET_DI_FPSCR(di_fpscr);
if (which == 0)
puts ("After setcontext the 64-bit FPSCR contains:");
else
puts ("After swapcontext the 64-bit FPSCR contains:");
printf("0x%.16llx\n",(unsigned long long int) di_fpscr);
test = (_FPSCR_TEST0_DRN | _FPSCR_TEST0_RN);
if((di_fpscr & (test)) != (test))
{
printf ("%s: DRN and RN bits set before getcontext were not preserved across [set|swap]context call: %m",__FUNCTION__);
_exit (3);
}
}
else
{
_GET_SI_FPSCR(di_fpscr);
if (which == 0)
puts ("After setcontext the 32-bit FPSCR contains:");
else
puts ("After swapcontext the 32-bit FPSCR contains:");
printf("0x%.8lx\n",(unsigned long int) di_fpscr);
test = _FPSCR_TEST0_RN;
if((di_fpscr & test) != test)
{
printf ("%s: RN bit set before getcontext was not preserved across [set|swap]context call: %m",__FUNCTION__);
_exit (4);
}
}
}
static void
check_called (void)
{
if (back_in_main == 0)
{
puts ("program did not reach main again");
_exit (5);
}
}
int
main (void)
{
atexit (check_called);
puts ("priming the FPSCR with a marker");
prime_special_regs (0);
puts ("making contexts");
if (getcontext (&ctx[0]) != 0)
{
if (errno == ENOSYS)
{
back_in_main = 1;
exit (0);
}
printf ("%s: getcontext: %m\n", __FUNCTION__);
exit (6);
}
/* Play some tricks with this context. */
if (++global == 1)
{
clear_special_regs ( );
if (setcontext (&ctx[0]) != 0)
{
printf ("%s: setcontext: %m\n", __FUNCTION__);
exit (7);
}
}
if (global != 2)
{
printf ("%s: 'global' not incremented twice\n", __FUNCTION__);
exit (8);
}
test_special_regs (0);
global = 0;
if (getcontext (&ctx[0]) != 0)
{
printf ("%s: getcontext: %m\n", __FUNCTION__);
exit (9);
}
if (++global == 1)
{
puts ("priming the FPSCR with a marker");
prime_special_regs (1);
puts ("swapping contexts");
if (swapcontext (&ctx[1], &ctx[0]) != 0)
{
printf ("%s: swapcontext: %m\n", __FUNCTION__);
exit (9);
}
}
if (global != 2)
{
printf ("%s: 'global' not incremented twice\n", __FUNCTION__);
exit (10);
}
test_special_regs (1);
puts ("back at main program");
back_in_main = 1;
puts ("test succeeded");
return 0;
}