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			370 lines
		
	
	
		
			9.2 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			370 lines
		
	
	
		
			9.2 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| /* Copyright (C) 2001,2002,2004,2006-2008,2009 Free Software Foundation, Inc.
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|    This file is part of the GNU C Library.
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|    Contributed by Ryan S. Arnold <rsa@us.ibm.com>
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|                   Sean Curry <spcurry@us.ibm.com>
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| 
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|    The GNU C Library is free software; you can redistribute it and/or
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|    modify it under the terms of the GNU Lesser General Public
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|    License as published by the Free Software Foundation; either
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|    version 2.1 of the License, or (at your option) any later version.
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| 
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|    The GNU C Library is distributed in the hope that it will be useful,
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|    but WITHOUT ANY WARRANTY; without even the implied warranty of
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|    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
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|    Lesser General Public License for more details.
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| 
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|    You should have received a copy of the GNU Lesser General Public
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|    License along with the GNU C Library; if not, see
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|    <http://www.gnu.org/licenses/>.  */
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| 
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| #include <errno.h>
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| #include <stdio.h>
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| #include <stdlib.h>
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| #include <string.h>
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| #include <ucontext.h>
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| #include <unistd.h>
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| #include <malloc.h>
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| #include <link.h>
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| #include <elf.h>
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| #include <sysdep.h>
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| #include <fpu_control.h>
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| 
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| static ucontext_t ctx[3];
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| 
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| 
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| volatile int global;
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| 
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| 
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| static int back_in_main;
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| 
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| 
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| volatile static ElfW(auxv_t) *auxv = NULL;
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| 
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| ElfW(Addr) query_auxv(int type)
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| {
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|   FILE *auxv_f;
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|   ElfW(auxv_t) auxv_struct;
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|   ElfW(auxv_t) *auxv_temp;
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|   int i = 0;
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| 
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|   /* if the /proc/self/auxv file has not been manually copied into the heap
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|      yet, then do it */
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| 
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|   if(auxv == NULL)
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|     {
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|       auxv_f = fopen("/proc/self/auxv", "r");
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| 
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|       if(auxv_f == 0)
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| 	{
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| 	  perror("Error opening file for reading");
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| 	  return 0;
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| 	}
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|       auxv = (ElfW(auxv_t) *)malloc(getpagesize());
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| 
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|       do
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| 	{
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| 	  fread(&auxv_struct, sizeof(ElfW(auxv_t)), 1, auxv_f);
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| 	  auxv[i] = auxv_struct;
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| 	  i++;
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| 	} while(auxv_struct.a_type != AT_NULL);
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|     }
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| 
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|   auxv_temp = (ElfW(auxv_t) *)auxv;
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|   i = 0;
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|   do
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|     {
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|       if(auxv_temp[i].a_type == type)
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| 	{
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| 	  return auxv_temp[i].a_un.a_val;
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| 	}
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|       i++;
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|     } while (auxv_temp[i].a_type != AT_NULL);
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| 
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|   return 0;
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| }
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| 
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| typedef unsigned long long di_fpscr_t __attribute__ ((__mode__ (__DI__)));
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| typedef unsigned int si_fpscr_t __attribute__ ((__mode__ (__SI__)));
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| 
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| #define _FPSCR_RESERVED 0xfffffff8ffffff04ULL
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| 
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| #define _FPSCR_TEST0_DRN 0x0000000400000000ULL
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| #define _FPSCR_TEST0_RN  0x0000000000000003ULL
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| 
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| #define _FPSCR_TEST1_DRN 0x0000000300000000ULL
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| #define _FPSCR_TEST1_RN  0x0000000000000002ULL
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| 
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| /* Macros for accessing the hardware control word on Power6[x].  */
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| # define _GET_DI_FPSCR(__fpscr) ({					     \
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|    union { double d;							     \
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|            di_fpscr_t fpscr; }						     \
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|      tmp __attribute__ ((__aligned__(8)));				     \
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|    __asm__ ("mffs 0; stfd%U0 0,%0" : "=m" (tmp.d) : : "fr0");		     \
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|    (__fpscr)=tmp.fpscr;							     \
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|    tmp.fpscr; })
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| 
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| /* We make sure to zero fp0 after we use it in order to prevent stale data
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|    in an fp register from making a test-case pass erroneously.  */
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| # define _SET_DI_FPSCR(__fpscr) {					     \
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|   union { double d; di_fpscr_t fpscr; }					     \
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|     tmp __attribute__ ((__aligned__(8)));				     \
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|   tmp.fpscr = __fpscr;							     \
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|   /* Set the entire 64-bit FPSCR.  */					     \
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|   __asm__ ("lfd%U0 0,%0; "						     \
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| 	   ".machine push; "						     \
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| 	   ".machine \"power6\"; "					     \
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| 	   "mtfsf 255,0,1,0; "						     \
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| 	   ".machine pop" : : "m" (tmp.d) : "fr0");			     \
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|   tmp.d = 0;								     \
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|   __asm__("lfd%U0 0,%0" : : "m" (tmp.d) : "fr0");			     \
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| }
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| 
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| # define _GET_SI_FPSCR(__fpscr) ({					     \
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|    union { double d;							     \
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|            si_fpscr_t cw[2]; }						     \
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|      tmp __attribute__ ((__aligned__(8)));				     \
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|    __asm__ ("mffs 0; stfd%U0 0,%0" : "=m" (tmp.d) : : "fr0");		     \
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|    (__fpscr)=tmp.cw[1];							     \
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|    tmp.cw[0]; })
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| 
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| /* We make sure to zero fp0 after we use it in order to prevent stale data
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|    in an fp register from making a test-case pass erroneously.  */
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| # define _SET_SI_FPSCR(__fpscr) {					     \
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|   union { double d; si_fpscr_t fpscr[2]; }				     \
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|     tmp __attribute__ ((__aligned__(8)));				     \
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|   /* More-or-less arbitrary; this is a QNaN. */				     \
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|   tmp.fpscr[0] = 0xFFF80000;						     \
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|   tmp.fpscr[1] = __fpscr;						     \
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|   __asm__ ("lfd%U0 0,%0; mtfsf 255,0" : : "m" (tmp.d) : "fr0");		     \
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|   tmp.d = 0;								     \
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|   __asm__("lfd%U0 0,%0" : : "m" (tmp.d) : "fr0");			     \
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| }
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| 
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| void prime_special_regs(int which)
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| {
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|   ElfW(Addr) a_val;
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| 
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|   di_fpscr_t di_fpscr __attribute__ ((__aligned__(8)));
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| 
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|   a_val = query_auxv(AT_HWCAP);
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|   if(a_val == -1)
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|     {
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|       puts ("querying the auxv for the hwcap failed");
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|       _exit (1);
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|     }
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| 
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|   /* Indicates a 64-bit FPSCR.  */
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|   if (a_val & PPC_FEATURE_HAS_DFP)
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|     {
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|       _GET_DI_FPSCR(di_fpscr);
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| 
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|       /* Overwrite the existing DRN and RN if there is one.  */
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|       if (which == 0)
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|         di_fpscr = ((di_fpscr & _FPSCR_RESERVED) | (_FPSCR_TEST0_DRN | _FPSCR_TEST0_RN));
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|       else
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|         di_fpscr = ((di_fpscr & _FPSCR_RESERVED) | (_FPSCR_TEST1_DRN | _FPSCR_TEST1_RN));
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|       puts ("Priming 64-bit FPSCR with:");
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|       printf("0x%.16llx\n",(unsigned long long int)di_fpscr);
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| 
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|       _SET_DI_FPSCR(di_fpscr);
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|     }
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|   else
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|     {
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|       puts ("32-bit FPSCR found and will be tested.");
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|       _GET_SI_FPSCR(di_fpscr);
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| 
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|       /* Overwrite the existing RN if there is one.  */
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|       if (which == 0)
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|         di_fpscr = ((di_fpscr & _FPSCR_RESERVED) | (_FPSCR_TEST0_RN));
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|       else
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|         di_fpscr = ((di_fpscr & _FPSCR_RESERVED) | (_FPSCR_TEST1_RN));
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|       puts ("Priming 32-bit FPSCR with:");
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|       printf("0x%.8lx\n",(unsigned long int) di_fpscr);
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| 
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|       _SET_SI_FPSCR(di_fpscr);
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|     }
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| }
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| 
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| void clear_special_regs(void)
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| {
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|   ElfW(Addr) a_val;
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| 
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|   di_fpscr_t di_fpscr __attribute__ ((__aligned__(8)));
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| 
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|   union {
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| 	  double d;
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| 	  unsigned long long int lli;
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| 	  unsigned int li[2];
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|   } dlli;
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| 
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|   a_val = query_auxv(AT_HWCAP);
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|   if(a_val == -1)
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|     {
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|       puts ("querying the auxv for the hwcap failed");
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|       _exit (1);
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|     }
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| 
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| #if __WORDSIZE == 32
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|   dlli.d = ctx[0].uc_mcontext.uc_regs->fpregs.fpscr;
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| #else
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|   dlli.d = ctx[0].uc_mcontext.fp_regs[32];
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| #endif
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| 
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|   puts("The FPSCR value saved in the ucontext_t is:");
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| 
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|   /* Indicates a 64-bit FPSCR.  */
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|   if (a_val & PPC_FEATURE_HAS_DFP)
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|     {
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|       printf("0x%.16llx\n",dlli.lli);
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|       di_fpscr = 0x0;
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|       puts ("Clearing the 64-bit FPSCR to:");
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|       printf("0x%.16llx\n",(unsigned long long int) di_fpscr);
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| 
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|       _SET_DI_FPSCR(di_fpscr);
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|     }
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|   else
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|     {
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|       printf("0x%.8x\n",(unsigned int) dlli.li[1]);
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|       di_fpscr = 0x0;
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|       puts ("Clearing the 32-bit FPSCR to:");
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|       printf("0x%.8lx\n",(unsigned long int) di_fpscr);
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| 
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|       _SET_SI_FPSCR(di_fpscr);
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|     }
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| }
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| 
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| void test_special_regs(int which)
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| {
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|   ElfW(Addr) a_val;
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|   unsigned long long int test;
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| 
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|   di_fpscr_t di_fpscr __attribute__ ((__aligned__(8)));
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| 
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|   a_val = query_auxv(AT_HWCAP);
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|   if(a_val == -1)
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|     {
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|       puts ("querying the auxv for the hwcap failed");
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|       _exit (2);
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|     }
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| 
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|   /* Indicates a 64-bit FPSCR.  */
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|   if (a_val & PPC_FEATURE_HAS_DFP)
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|     {
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|       _GET_DI_FPSCR(di_fpscr);
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| 
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|       if (which == 0)
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| 	puts ("After setcontext the 64-bit FPSCR contains:");
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|       else
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| 	puts ("After swapcontext the 64-bit FPSCR contains:");
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| 
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|       printf("0x%.16llx\n",(unsigned long long int) di_fpscr);
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|       test = (_FPSCR_TEST0_DRN | _FPSCR_TEST0_RN);
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|       if((di_fpscr & (test)) != (test))
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|         {
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| 	  printf ("%s: DRN and RN bits set before getcontext were not preserved across [set|swap]context call: %m",__FUNCTION__);
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| 	  _exit (3);
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|         }
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|     }
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|   else
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|     {
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|       _GET_SI_FPSCR(di_fpscr);
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|       if (which == 0)
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| 	puts ("After setcontext the 32-bit FPSCR contains:");
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|       else
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| 	puts ("After swapcontext the 32-bit FPSCR contains:");
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| 
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|       printf("0x%.8lx\n",(unsigned long int) di_fpscr);
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|       test = _FPSCR_TEST0_RN;
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|       if((di_fpscr & test) != test)
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|         {
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| 	  printf ("%s: RN bit set before getcontext was not preserved across [set|swap]context call: %m",__FUNCTION__);
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| 	  _exit (4);
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|         }
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|     }
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| }
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| 
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| 
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| static void
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| check_called (void)
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| {
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|   if (back_in_main == 0)
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|     {
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|       puts ("program did not reach main again");
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|       _exit (5);
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|     }
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| }
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| 
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| 
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| int
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| main (void)
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| {
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|   atexit (check_called);
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| 
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|   puts ("priming the FPSCR with a marker");
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|   prime_special_regs (0);
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| 
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|   puts ("making contexts");
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|   if (getcontext (&ctx[0]) != 0)
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|     {
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|       if (errno == ENOSYS)
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| 	{
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| 	  back_in_main = 1;
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| 	  exit (0);
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| 	}
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| 
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|       printf ("%s: getcontext: %m\n", __FUNCTION__);
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|       exit (6);
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|     }
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| 
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|   /* Play some tricks with this context.  */
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|   if (++global == 1)
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|     {
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|     clear_special_regs ( );
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|     if (setcontext (&ctx[0]) != 0)
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|       {
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| 	printf ("%s: setcontext: %m\n", __FUNCTION__);
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| 	exit (7);
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|       }
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|     }
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|   if (global != 2)
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|     {
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|       printf ("%s: 'global' not incremented twice\n", __FUNCTION__);
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|       exit (8);
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|     }
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| 
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|   test_special_regs (0);
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| 
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|   global = 0;
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|   if (getcontext (&ctx[0]) != 0)
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|     {
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|       printf ("%s: getcontext: %m\n", __FUNCTION__);
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|       exit (9);
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|     }
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| 
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|   if (++global == 1)
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|     {
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|       puts ("priming the FPSCR with a marker");
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|       prime_special_regs (1);
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| 
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|       puts ("swapping contexts");
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|       if (swapcontext (&ctx[1], &ctx[0]) != 0)
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|         {
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|           printf ("%s: swapcontext: %m\n", __FUNCTION__);
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|           exit (9);
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|         }
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|     }
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|   if (global != 2)
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|     {
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|       printf ("%s: 'global' not incremented twice\n", __FUNCTION__);
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|       exit (10);
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|     }
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| 
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|   test_special_regs (1);
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| 
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|   puts ("back at main program");
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|   back_in_main = 1;
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| 
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|   puts ("test succeeded");
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|   return 0;
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| }
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