mirror of
https://github.com/tobast/libunwind-eh_elf.git
synced 2024-12-28 13:53:43 +01:00
76 lines
1.3 KiB
C
76 lines
1.3 KiB
C
#include <stdio.h>
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#include <stdlib.h>
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#include <sys/time.h>
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#include <libunwind.h>
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#define panic(args...) \
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do { fprintf (stderr, args); exit (-1); } while (0)
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static inline double
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gettime (void)
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{
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struct timeval tv;
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gettimeofday(&tv, NULL);
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return tv.tv_sec + 1e-6*tv.tv_usec;
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}
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static int
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measure_unwind (int maxlevel)
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{
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double stop, mid, start;
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unw_cursor_t cursor;
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unw_context_t uc;
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int ret, level = 0;
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start = gettime ();
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unw_getcontext (&uc);
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if (unw_init_local (&cursor, &uc) < 0)
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panic ("unw_init_local() failed\n");
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mid = gettime ();
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do
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{
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ret = unw_step (&cursor);
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if (ret < 0)
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panic ("unw_step() failed\n");
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++level;
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}
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while (ret > 0);
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stop = gettime ();
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if (level <= maxlevel)
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panic ("Unwound only %d levels, expected at least %d levels",
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level, maxlevel);
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printf ("initialization time = %gnsec, time per unwind-step = %gnsec\n",
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1e9*(mid - start), 1e9*(stop - mid)/level);
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}
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static int
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f1 (int level, int maxlevel)
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{
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if (level == maxlevel)
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return measure_unwind (maxlevel);
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else
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/* defeat last-call/sibcall optimization */
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return f1 (level + 1, maxlevel) + level;
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}
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int
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main (int argc, char **argv)
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{
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int i, maxlevel = 100;
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if (argc > 1)
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maxlevel = atol (argv[1]);
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for (i = 0; i < 10; ++i)
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f1 (0, maxlevel);
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return 0;
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}
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