| Last change
 on this file since 4aae2bd was             525b5ef, checked in by Peter A. Buhr <pabuhr@…>, 6 years ago | 
        
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add documentation
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Property                 mode
 set to                 100644 | 
        
          | File size:
            571 bytes | 
      
      
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| 1 | #include <stdio.h> | 
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| 2 |  | 
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| 3 | #include "bench.h" | 
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| 4 |  | 
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| 5 | // Does a "lock add" on entry and a "lock sub" on exit => 2 atomic instructions making it the most expensive | 
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| 6 | // atomic test. | 
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| 7 |  | 
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| 8 | volatile int value; | 
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| 9 |  | 
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| 10 | void __attribute__((noinline)) do_call() { | 
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| 11 | __atomic_add_fetch( &value, 1, __ATOMIC_SEQ_CST ); | 
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| 12 | asm volatile (""); | 
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| 13 | __atomic_sub_fetch( &value, 1, __ATOMIC_SEQ_CST ); | 
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| 14 | } | 
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| 15 |  | 
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| 16 | int main( int argc, char * argv[] ) { | 
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| 17 | BENCH_START() | 
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| 18 | BENCH( | 
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| 19 | for (size_t i = 0; i < times; i++) { | 
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| 20 | do_call(); | 
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| 21 | }, | 
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| 22 | result | 
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| 23 | ) | 
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| 24 | printf( "%g\n", result ); | 
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| 25 | } | 
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| 26 |  | 
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| 27 | // Local Variables: // | 
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| 28 | // tab-width: 4 // | 
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| 29 | // End: // | 
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