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Evghenii
2014-01-29 11:32:53 +01:00
parent 922018ac2d
commit 2634ae65fd
1 changed files with 24 additions and 32 deletions
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56
examples_ptx/radixSort/radixSort.ispc
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@@ -1,4 +1,4 @@
#define NUMBITS 8
#define NUMBITS 4
#define NUMDIGITS (1<<NUMBITS)
typedef int64 Key;
@@ -26,26 +26,16 @@ void countPass(
foreach (digit = 0 ... NUMDIGITS)
counts[digit] = 0;
#if 1
foreach (i = 0 ... nloc)
{
sorted[i] = keys[i];
const int key = mask & ((unsigned int)keys[i] >> bit);
uniform int skey;
if (reduce_equal(key, &skey) == true)
counts[skey] += reduce_add(1);
else
{
#ifdef __NVPTX__
atomic_add_global(&counts[key], 1);
atomic_add_global(&counts[key], 1);
#else
atomic_add_local(&counts[key], 1);
atomic_add_local(&counts[key], 1);
#endif
}
}
#else
#endif
foreach (digit = 0 ... NUMDIGITS)
atomic_add_global(&countsGlobal[digit], counts[digit]);
@@ -75,6 +65,8 @@ void sortPass(
const int unitScan = exclusive_scan_add(1);
int lkeys[NUMDIGITS] = {0};
/* copy digit offset from Gmem to Lmem */
uniform int digitOffsets[NUMDIGITS];
foreach (digit = 0 ... NUMDIGITS)
@@ -85,26 +77,8 @@ void sortPass(
{
const int key = mask & ((unsigned int)keys[i] >> bit);
int scatter;
#if 0
/* serialize exuection to test correctness of algorithm */
foreach_active(iv)
scattter = digitOffsets[key]++;
#else
if (reduce_equal(key) == true)
digitOffsets[key] = (scatter = digitOffsets[key] + unitScan) + 1;
else
{
#ifdef __NVPTX__
/* there is a bug, not clear where exectly (perhaps due to optimizations),
* This complex code restored correctness */
/* :S */
if (programIndex < 16) {if (key < NUMDIGITS) scatter = atomic_add_global(&digitOffsets[key],1);}
else {if (key < NUMDIGITS) scatter = atomic_add_global(&digitOffsets[key],1);}
#else
scatter = atomic_add_local(&digitOffsets[key],1);
#endif
}
#endif
scatter = digitOffsets[key]++;
sorted [scatter] = keys[i];
}
}
@@ -126,6 +100,7 @@ void partialScanLocal(
uniform int (* uniform excScanBlock)[NUMDIGITS] = (uniform int (*)[NUMDIGITS])excScanAll;
uniform int (* uniform partialSum)[NUMDIGITS] = (uniform int (*)[NUMDIGITS])partialSumAll;
#if 0
foreach (digit = 0 ... NUMDIGITS)
{
int prev = bbeg == 0 ? excScanBlock[0][digit] : 0;
@@ -137,6 +112,21 @@ void partialScanLocal(
}
partialSum[blockIdx][digit] = excScanBlock[bend-1][digit] + countsBlock[bend-1][digit];
}
#else
int prev[NUMDIGITS];
for (int digit = 0; digit < NUMDIGITS; digit++)
prev[digit] = bbeg == 0 ? excScanBlock[0][digit] : 0;
foreach_tiled (block = bbeg ... bend, digit = 0 ... NUMDIGITS)
{
const int y = countsBlock[block][digit];
excScanBlock[block][digit] = prev[digit];
prev[digit] += y;
}
foreach (digit = 0 ... NUMDIGITS)
partialSum[blockIdx][digit] = excScanBlock[bend-1][digit] + countsBlock[bend-1][digit];
#endif
}
task
@@ -310,6 +300,7 @@ export void radixSort(
/* computing offsets for each digit */
radixExclusiveScan(numBlocks, excScan, counts, partialSum, prefixSum);
#if 1
/* sorting */
launch [numBlocks]
sortPass(
@@ -319,6 +310,7 @@ export void radixSort(
numElements,
excScan);
sync;
#endif
}
}