我正在尝试构建一个内核来进行并行字符串搜索。为此,我倾向于使用有限状态机。fsm 的转换表处于内核参数状态。编码:
__kernel void Find ( __constant char *text,
const int offset,
const int tlenght,
__constant char *characters,
const int clength,
const int maxlength,
__constant int *states,
const int statesdim){
private char c;
private int state;
private const int id = get_global_id(0);
if (id<(tlenght-maxlength)) {
private int cIndex,sd,s,k;
for (int i=0; i<maxlength; i++) {
c = text[i+offset];
cIndex = -1;
for (int j=0; j<clength; j++) {
if (characters[j]==c) {
cIndex = j;
}
}
if (cIndex==-1) {
state = 0;
break;
} else {
s = states[state+cIndex*statesdim];
}
if (state<=0) break;
}
}
}
如果我使用 iocgui 编译这个内核,我会得到结果:
Using default instruction set architecture.
Intel OpenCL CPU device was found!
Device name: Pentium(R) Dual-Core CPU T4400 @ 2.20GHz
Device version: OpenCL 1.1 (Build 31360.31426)
Device vendor: Intel(R) Corporation
Device profile: FULL_PROFILE
Build started
Kernel <Find> was successfully vectorized
Done.
Build succeeded!
当我更改确定新状态的行时:
state = states[state+cIndex*statesdim];
结果是:
Using default instruction set architecture.
Intel OpenCL CPU device was found!
Device name: Pentium(R) Dual-Core CPU T4400 @ 2.20GHz
Device version: OpenCL 1.1 (Build 31360.31426)
Device vendor: Intel(R) Corporation
Device profile: FULL_PROFILE
Build started
Kernel <Find> was not vectorized
Done.
Build succeeded!