tests/power_insn_available.c

   1 #include <stdio.h>
   2 #include <stdbool.h>
   3 #include <stdlib.h>
   4 #include <string.h>
   5 #include <signal.h>
   6 #include <setjmp.h>
   7
   8 typedef enum exit_codes_ {
   9
  10 #if defined(VGA_ppc32) || defined(VGA_ppc64be) || defined(VGA_ppc64le)
  11   /* If the insn that got queried for: exists */
  12   POWER_INSN_AVAILABLE    = 0,
  13   /* If the insn that got queried for: does not exist on this platform */
  14   POWER_INSN_UNAVAILABLE  = 1,
  15   /* If the insn that got queried for: does not exist in the vocabulary of this program */
  16   POWER_INSN_UNRECOGNIZED = 2,
  17
  18   /* Note: Please keep USAGE_ERROR last. */
  19   USAGE_ERROR
  20 #else
  21   /* When not on a POWER system: */
  22   NOT_POWER_ARCH          = 255,
  23 #endif
  24
  25 } exit_code;
  26
  27 #if defined(VGA_ppc32) || defined(VGA_ppc64be) || defined(VGA_ppc64le)
  28 /* Signal Handling support for unsupported instructions. */
  29 static jmp_buf unsup_insn_env;
  30 static void unsup_insn_handler(int signal_number)
  31 {
  32   if (signal_number == SIGILL)
  33     longjmp(unsup_insn_env, 1);
  34   return;
  35 }
  36 static struct sigaction unsup_insn_action = {
  37   .sa_handler = &unsup_insn_handler,
  38 };
  39
  40 /* Instruction existence tests. */
  41 static bool dcbzl_available(void)
  42 {
  43 #define MAX_DCBZL_SZB (128) /* largest known effect of dcbzl */
  44   char *test_block = NULL;
  45   register char *rb asm ("r14");
  46   int err;
  47   bool dcbzl_exists = false;
  48
  49   err = posix_memalign ((void **)&test_block, MAX_DCBZL_SZB, 4 * MAX_DCBZL_SZB);
  50   if (err) {
  51     fprintf(stderr, "posix_memalign() failed (err = %d [%s])\n", err, strerror(err));
  52     return err;
  53   }
  54
  55   rb = test_block;
  56
  57   if (setjmp(unsup_insn_env) != 0)
  58     dcbzl_exists = false;
  59   else {
  60     sigaction(SIGILL, &unsup_insn_action, NULL);
  61     asm volatile ("dcbzl 0, %[RB]" : : [RB] "r" (rb));
  62     dcbzl_exists = true;
  63   }
  64
  65   free(test_block);
  66   return dcbzl_exists;
  67 }
  68 #endif
  69
  70 /* main() */
  71 int main(int argc, char **argv)
  72 {
  73   exit_code status;
  74
  75 #if defined(VGA_ppc32) || defined(VGA_ppc64be) || defined(VGA_ppc64le)
  76   char *insn;
  77   if (argc != 2) {
  78     fprintf(stderr, "usage: power_insn_available <insn>\n" );
  79     exit(USAGE_ERROR);
  80   }
  81
  82   insn = argv[1];
  83   if (strcmp (insn, "dcbzl") == 0)
  84     status = ((dcbzl_available ()) ? POWER_INSN_AVAILABLE : POWER_INSN_UNAVAILABLE);
  85   else
  86     /* power_insn_available has not been taught anything about this insn yet. */
  87     status = POWER_INSN_UNRECOGNIZED;
  88 #else
  89     status = NOT_POWER_ARCH;
  90 #endif
  91   return status;
  92 }