55 lines
2.1 KiB
Plaintext
55 lines
2.1 KiB
Plaintext
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//========================================================================================================================================================================================================200
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// findK function
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//========================================================================================================================================================================================================200
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__global__ void
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findK( long height,
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knode *knodesD,
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long knodes_elem,
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record *recordsD,
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long *currKnodeD,
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long *offsetD,
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int *keysD,
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record *ansD)
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{
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// private thread IDs
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int thid = threadIdx.x;
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int bid = blockIdx.x;
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// processtree levels
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int i;
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for(i = 0; i < height; i++){
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// if value is between the two keys
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if((knodesD[currKnodeD[bid]].keys[thid]) <= keysD[bid] && (knodesD[currKnodeD[bid]].keys[thid+1] > keysD[bid])){
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// this conditional statement is inserted to avoid crush due to but in original code
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// "offset[bid]" calculated below that addresses knodes[] in the next iteration goes outside of its bounds cause segmentation fault
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// more specifically, values saved into knodes->indices in the main function are out of bounds of knodes that they address
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if(knodesD[offsetD[bid]].indices[thid] < knodes_elem){
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offsetD[bid] = knodesD[offsetD[bid]].indices[thid];
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}
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}
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__syncthreads();
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// set for next tree level
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if(thid==0){
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currKnodeD[bid] = offsetD[bid];
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}
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__syncthreads();
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}
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//At this point, we have a candidate leaf node which may contain
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//the target record. Check each key to hopefully find the record
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if(knodesD[currKnodeD[bid]].keys[thid] == keysD[bid]){
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ansD[bid].value = recordsD[knodesD[currKnodeD[bid]].indices[thid]].value;
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}
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}
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//========================================================================================================================================================================================================200
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// End
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//========================================================================================================================================================================================================200
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