63 lines
2.6 KiB
Plaintext
63 lines
2.6 KiB
Plaintext
|
/*
|
||
|
|
* Copyright Ana Balevic, 2008-2009. All rights reserved.
|
||
|
|
*/
|
||
|
|
#ifndef _PABIO_KERNEL2_H_
|
||
|
|
#define _PABIO_KERNEL2_H_
|
||
|
|
|
||
|
|
#include "parameters.h"
|
||
|
|
|
||
|
|
/* PARALLEL PUT BITS IMPLEMENTATION (CUDA1.1+ compatible)
|
||
|
|
* Set numbits in the destination word out[kc] starting from the position startbit
|
||
|
|
* Implementation comments:
|
||
|
|
* Second atomic operation actually sets these bits to the value stored in the codeword; the other bits are left unotuched
|
||
|
|
* First atomic operation is a necessary prepration - we change only the bits that will be affected by the codeword to be written to 1s
|
||
|
|
* in order for set bits to work with using atomicand.
|
||
|
|
* TODOs: benchmark performance 1) gm atomics vs sm atomics; 2) memset at init time vs. atomicOr
|
||
|
|
*/
|
||
|
|
__device__ void static put_bits_atomic2(unsigned int* out, unsigned int kc,
|
||
|
|
unsigned int startbit, unsigned int numbits,
|
||
|
|
unsigned int codeword) {
|
||
|
|
unsigned int cw32 = codeword;
|
||
|
|
unsigned int restbits = 32-startbit-numbits;
|
||
|
|
|
||
|
|
/* 1. Prepare the memory location */
|
||
|
|
#ifndef MEMSET0 //Can remove this part if the contents of the memory are already set to all 0s
|
||
|
|
unsigned int mask = ((1<<numbits)-1); // -> 0000...001111
|
||
|
|
mask<<=restbits; //fill in zeros at the back positions -> 0000...001111000 -> 11111110000111111111111 (in order not to and other positions)
|
||
|
|
atomicAnd(&out[kc], ~mask); //set 0s in the destination from startbit in the len of numbits
|
||
|
|
#endif
|
||
|
|
|
||
|
|
/* 2. Write the codeword */
|
||
|
|
cw32 = cw32<<restbits;
|
||
|
|
atomicOr(&out[kc], cw32);
|
||
|
|
}
|
||
|
|
|
||
|
|
|
||
|
|
|
||
|
|
/* PARALLEL PUT BITS IMPLEMENTATION (CUDA1.1+ compatible)
|
||
|
|
* Checkes if the part of the word to be written matches whole memory location, and if yes, avoids using the atmoics.
|
||
|
|
* Experience: no benefits, even a bit slower on CUDA.
|
||
|
|
*/
|
||
|
|
__device__ void static put_bits_atomic2a(unsigned int* out, unsigned int kc,
|
||
|
|
unsigned int startbit, unsigned int numbits,
|
||
|
|
unsigned int codeword) {
|
||
|
|
unsigned int cw32 = codeword;
|
||
|
|
unsigned int restbits = 32-startbit-numbits;
|
||
|
|
|
||
|
|
/* 1. Prepare the memory location */
|
||
|
|
#ifndef MEMSET0 //Can remove this part if the contents of the memory are already set to all 0s
|
||
|
|
unsigned int mask = ((1<<numbits)-1); // -> 0000...001111
|
||
|
|
mask<<=restbits; //fill in zeros at the back positions -> 0000...001111000 -> 11111110000111111111111 (in order not to and other positions)
|
||
|
|
atomicAnd(&out[kc], ~mask); //set 0s in the destination from startbit in the len of numbits
|
||
|
|
#endif
|
||
|
|
|
||
|
|
/* 2. Write the codeword */
|
||
|
|
if (startbit == 0 && restbits == 0) {
|
||
|
|
out[kc] = cw32;
|
||
|
|
} else {
|
||
|
|
cw32 = cw32<<restbits;
|
||
|
|
atomicOr(&out[kc], cw32);
|
||
|
|
}
|
||
|
|
}
|
||
|
|
#endif //ifndef _PABIO_KERNEL_H_
|