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atomics.h
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27 
28 #pragma once
29 
30 #include <nvbio/basic/types.h>
31 
32 //#define USE_WARP_VOTE
33 
34 
35 namespace nvbio {
36 
38 {
39 #ifdef USE_WARP_VOTE
40  *(volatile uint32*)count += __popc( __ballot( true ) );
41 #else
42  atomicInc( count, uint32(-1) );
43 #endif
44 }
46 {
47 #ifdef USE_WARP_VOTE
48  const volatile uint32 val = *(volatile uint32*)count;
49  const volatile uint32 mask = __ballot( true );
50  const uint32 warp_count = __popc( mask );
51  const uint32 warp_scan = __popc( mask >> warp_tid() ) - 1u;
52  if (warp_scan == 0)
53  *(volatile uint32*)count = val + warp_count;
54  return val + warp_scan;
55 #else
56  return atomicInc( count, uint32(-1) );
57 #endif
58 }
60 {
61 #ifdef USE_WARP_VOTE
62  *(volatile uint32*)count -= __popc( __ballot( true ) );
63 #else
64  atomicDec( count, uint32(-1) );
65 #endif
66 }
68 {
69 #ifdef USE_WARP_VOTE
70  const volatile uint32 val = *(volatile uint32*)count;
71  const volatile uint32 mask = __ballot( true );
72  const uint32 warp_count = __popc( mask );
73  const uint32 warp_scan = __popc( mask >> warp_tid() ) - 1u;
74  if (warp_scan == 0)
75  *(volatile uint32*)count = val - warp_count;
76  return val - warp_scan;
77 #else
78  return atomicDec( count, uint32(-1) );
79 #endif
80 }
81 
82 } // namespace nvbio