ADT
arm-eh
ast-experimental
enum
forall-pointer-decay
jacob/cs343-translation
jenkins-sandbox
new-ast
new-ast-unique-expr
pthread-emulation
qualifiedEnum
Last change
on this file since 6dc19544 was fe065c3, checked in by Peter A. Buhr <pabuhr@…>, 6 years ago |
new CFA generator and qthreads tests
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-
Property mode
set to
100644
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File size:
1.4 KB
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Rev | Line | |
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[fe065c3] | 1 | #include <stdio.h>
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| 2 | #include <stdint.h> // uintptr_t
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| 3 |
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| 4 | #include "bench.h"
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| 5 |
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| 6 | #define CALIGN __attribute__(( aligned (CACHE_ALIGN) ))
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| 7 | #define CACHE_ALIGN 128
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| 8 | #define Pause() __asm__ __volatile__ ( "pause" : : : )
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| 9 |
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| 10 | typedef uintptr_t TYPE; // addressable word-size
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| 11 | static volatile TYPE lock __attribute__(( aligned (128) )); // Intel recommendation
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| 12 | static TYPE PAD CALIGN __attribute__(( unused )); // protect further false sharing
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| 13 |
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| 14 | static inline void spin_lock( volatile TYPE *lock ) {
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| 15 | enum { SPIN_START = 4, SPIN_END = 64 * 1024, };
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| 16 | unsigned int spin = SPIN_START;
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| 17 |
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| 18 | for ( unsigned int i = 1;; i += 1 ) {
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| 19 | if ( *lock == 0 && __atomic_test_and_set( lock, __ATOMIC_ACQUIRE ) == 0 ) break;
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| 20 | for ( volatile unsigned int s = 0; s < spin; s += 1 ) Pause(); // exponential spin
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| 21 | //spin += spin; // powers of 2
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| 22 | if ( i % 64 == 0 ) spin += spin; // slowly increase by powers of 2
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| 23 | if ( spin > SPIN_END ) spin = SPIN_START; // prevent overflow
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| 24 | } // for
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| 25 | } // spin_lock
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| 26 |
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| 27 | static inline void spin_unlock( volatile TYPE *lock ) {
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| 28 | __atomic_clear( lock, __ATOMIC_RELEASE );
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| 29 | } // spin_unlock
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| 30 |
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| 31 | void __attribute__((noinline)) do_call() {
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| 32 | spin_lock( &lock );
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| 33 | // asm volatile ("");
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| 34 | spin_unlock( &lock );
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| 35 | }
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| 36 |
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| 37 | int main(int argc, char* argv[]) {
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| 38 | BENCH(
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| 39 | for (size_t i = 0; i < n; i++) {
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| 40 | do_call();
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| 41 | },
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| 42 | result
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| 43 | )
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| 44 |
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| 45 | printf("%g\n", result);
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| 46 | }
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| 47 |
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| 48 | // Local Variables: //
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| 49 | // tab-width: 4 //
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| 50 | // End: //
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