• <ins id="pjuwb"></ins>
    <blockquote id="pjuwb"><pre id="pjuwb"></pre></blockquote>

    <noscript id="pjuwb"></noscript>
          <sup id="pjuwb"><pre id="pjuwb"></pre></sup>

            <dd id="pjuwb"></dd>
            <abbr id="pjuwb"></abbr>
            

    
            

            




            







												


        

            
	
            
		
			

            

            
	
            
		
			
            string
            
			string
		            		
	
            

            

            

            
	
            

            posts - 27, comments - 177, trackbacks - 0, articles - 0
            
	
 
C++博客 ::
首頁 ::
新隨筆 ::
聯(lián)系 ::
聚合
 ::
管理


            
		            		
	
            
	
            
		
			
            
			
            
		            		
		
			
            
				
					
	
            
		
            
			
            
				 基于sse2的strstr函數(shù)
			
            
 			Posted on 2008-10-28 21:47 djx_zh 閱讀(2890) 評論(7)  編輯 收藏 引用  
			
			


		
            
		
             download the code
            昨天實現(xiàn)了基于int類型的strstr函數(shù)，可以獲得1~2X左右的加速。今天按 lstrstr的流程實現(xiàn)了基于SSE2的STRSTR函數(shù)?？梢缘玫?~4X左右的加速。


              1 char* lstrstrsse(char* text, char* pattern)
              2 {
              3     __m128i * sseiPtr = (__m128i *) text;
              4     unsigned char * chPtrAligned = (unsigned char*)text;
              5     __m128i sseiWord0 ;//= *sseiPtr ;
              6     __m128i sseiWord1 ;//= *sseiPtr ;
              7     __m128i sseiZero = _mm_set1_epi8(0);
              8     char chara = pattern[0];
              9     char charb = pattern[1];
             10     register __m128i byte16a;
             11     register __m128i byte16b;
             12     char* bytePtr =text;
             13     if(pattern ==NULL) return NULL;
             14     if(pattern[0] == 0) return NULL;
             15     if(pattern[1] == 0) return lstrchr(text,pattern[0]); 
             16     byte16a = _mm_set1_epi8(chara);
             17     byte16b = _mm_set1_epi8(charb);
             18 // process the unaligned bytes
             19 
             20 // the aligned bytes
             21 alignStart:
             22     sseiWord0 = *sseiPtr;
             23     sseiWord1 = *(sseiPtr+1);
             24     while( haszeroByte(sseiWord0,sseiWord1,sseiZero) ==0) 
             25     {
             26         unsigned int reta ;
             27 searcha:
             28         reta = hasByteC(sseiWord0,sseiWord1,  byte16a);
             29         if(reta!=0 ) {
             30             unsigned int retb ;
             31 findouta:        
             32             retb = hasByteC(sseiWord0,sseiWord1,  byte16b);
             33 findoutb:
             34             if(((reta<<1) & retb)){
             35                 // have ab
             36                 int i=1;
             37                 char * bytePtr0 = (char*) ( sseiPtr );
             38                 int j;
             39                 //printf("test::%0x,%d\n",reta ,bytePtr0 -text);
             40                 bytePtr = (char*) ( sseiPtr );
             41                 for(j =0;j<8;j++){
             42                     if(reta & 0xff) {
             43                         if(bytePtr0[0] == chara){
             44                             i =1;
             45                             bytePtr = bytePtr0 ;
             46                             while((pattern[i] )&&(bytePtr[i] == pattern[i])) i++;
             47                             if(pattern[i] == 0) return bytePtr;
             48                         }
             49                         if(bytePtr0[1] == chara){
             50                             i =1;
             51                             bytePtr = bytePtr0 + 1;
             52                             while((pattern[i] )&&(bytePtr[i] == pattern[i])) i++;
             53                             if(pattern[i] == 0) return bytePtr;
             54                         }
             55                         if(bytePtr0[2] == chara){
             56                             i =1;
             57                             bytePtr = bytePtr0 + 2;
             58                             while((pattern[i] )&&(bytePtr[i] == pattern[i])) i++;
             59                             if(pattern[i] == 0) return bytePtr;
             60                         }
             61                         if(bytePtr0[3] == chara){
             62                             i =1;
             63                             bytePtr = bytePtr0 + 3;
             64                             while((pattern[i] )&&(bytePtr[i] == pattern[i])) i++;
             65                             if(pattern[i] == 0) return bytePtr;
             66                         }
             67                     }
             68                     reta = reta >> 4;
             69                     bytePtr0 += 4;
             70                 }
             71             }
             72             // search b
             73             sseiPtr += 2;
             74             sseiWord0 = *sseiPtr;
             75             sseiWord1 = *(sseiPtr+1);
             76 
             77             while( haszeroByte(sseiWord0,sseiWord1,sseiZero) ==0){ 
             78                 retb = hasByteC(sseiWord0,sseiWord1,  byte16b);
             79                 if(retb !=0){
             80                     // findout b
             81                     if((*((char*) sseiPtr)) == charb){
             82                         //b000
             83                         char * bytePtr = ((char*) ( sseiPtr )) -1;
             84                         if(bytePtr[0] == chara){
             85                             int i=1;
             86                             while((pattern[i] )&&(bytePtr[i] == pattern[i])) i++;
             87                             if(pattern[i] == 0) return bytePtr;
             88                             if(bytePtr[i] == 0) return NULL;
             89                         }
             90 
             91                     }
             92                     reta = hasByteC(sseiWord0,sseiWord1,  byte16a);
             93                     if(reta !=0) 
             94                         goto findoutb;
             95                     else{
             96                         goto nextWord;                    
             97                     }
             98                 }
             99                 sseiPtr += 2;
            100                 sseiWord0 = *sseiPtr;
            101                 sseiWord1 = *(sseiPtr+1);
            102             }
            103             // search  from (char*)sseiPtr
            104             char * bytePtr = ((char*) ( sseiPtr )) -1;
            105             if(bytePtr[0] == chara){
            106                 int i=1;
            107                 while((pattern[i] )&&(bytePtr[i] == pattern[i])) i++;
            108                 if(pattern[i] == 0) return bytePtr;
            109             }
            110 
            111             goto prePareForEnd;
            112         }
            113 nextWord:
            114         sseiPtr += 2;
            115         sseiWord0 = *sseiPtr;
            116         sseiWord1 = *(sseiPtr+1);
            117     }
            118 prePareForEnd:
            119     {
            120         unsigned int reta;
            121         unsigned int retb;
            122         reta =hasByteC(sseiWord0,sseiWord1,  byte16a);
            123         retb =hasByteC(sseiWord0,sseiWord1,  byte16b);
            124         if(((reta<<1) & retb)){
            125             bytePtr = (char*)sseiPtr;
            126             while(*bytePtr){
            127                 if(*bytePtr == chara) {
            128                     int i=1;
            129                     while((pattern[i] )&&(bytePtr[i] == pattern[i])) i++;
            130                     if(pattern[i] == 0) return bytePtr;
            131                     if(bytePtr[i] == 0) return NULL;
            132 
            133                 }
            134                 bytePtr++;
            135             }
            136         }
            137     }
            138     return NULL;
            139 }
            140 
            
	
            


            
	    
    

            Feedback
            
	
			
            
				
            
					
            
						# re:  基于sse2的strstr函數(shù)  回復  更多評論
						  
					
            
					2008-10-30 00:53 by 肥仔
				
            
				
            超過了C的strstr?
            
			
            
		
			
            
				
            
					
            
						# re:  基于sse2的strstr函數(shù)  回復  更多評論
						  
					
            
					2008-10-30 09:33 by djxzh
				
            
				
            @肥仔
            就目前的測試結(jié)果，是這樣。還沒有測試最壞情況下會是什么結(jié)果。
            
			
            
		
			
            
				
            
					
            
						# re:  基于sse2的strstr函數(shù)[未登錄]  回復  更多評論
						  
					
            
					2008-10-30 10:35 by megax
				
            
				
            做一個從后面開始查找的試試？
            
			
            
		
			
            
				
            
					
            
						# re:  基于sse2的strstr函數(shù)  回復  更多評論
						  
					
            
					2008-10-30 10:41 by djxzh
				
            
				
            @megax
            你是說BM之類的算法嗎？那些算法需要對模式串預處理。
            
			
            
		
			
            
				
            
					
            
						# re:  基于sse2的strstr函數(shù)  回復  更多評論
						  
					
            
					2008-10-30 10:54 by vczh
				
            
				
            用了SSE的指令集就可以同時計算一小部分內(nèi)容了。
            
			
            
		
			
            
				
            
					
            
						# re:  基于sse2的strstr函數(shù)[未登錄]  回復  更多評論
						  
					
            
					2008-10-31 12:47 by megax
				
            
				
            不是，我說的是從一個字符串后面開始查找想要查找的內(nèi)容。不是說具體的算法
            
			
            
		
			
            
				
            
					
            
						# re:  基于sse2的strstr函數(shù)  回復  更多評論
						  
					
            
					2008-11-01 11:02 by 金山詞霸2008
				
            
				
            沒想到strstr函數(shù)的設計還這么復雜
            
			
            
		




            






            

				
			
            
		            		
	
            
	
            
		
			


		
	
            

            

    
    







            
	   
	



97久久国产亚洲精品超碰热|
国产精品毛片久久久久久久|
91久久精品国产成人久久|
蜜桃麻豆www久久|
久久综合亚洲色HEZYO社区|
91精品国产乱码久久久久久|
夜夜亚洲天天久久|
久久笫一福利免费导航|
国产亚洲美女精品久久久|
久久99精品久久只有精品|
久久精品国产2020|
7777精品伊人久久久大香线蕉|
亚洲精品乱码久久久久久|
亚洲精品国产字幕久久不卡|
欧美日韩中文字幕久久伊人|
亚洲中文精品久久久久久不卡|
香蕉久久夜色精品国产2020|
国产一久久香蕉国产线看观看|
久久亚洲精品无码AV红樱桃|
亚洲AV乱码久久精品蜜桃|
中文字幕久久欲求不满|
亚洲AV成人无码久久精品老人
|
少妇内射兰兰久久|
激情五月综合综合久久69|
久久精品国产亚洲77777|
久久国产色AV免费看|
久久人妻AV中文字幕|
亚洲第一永久AV网站久久精品男人的天堂AV
|
久久久久亚洲精品天堂|
麻豆精品久久久久久久99蜜桃|
99久久精品国产一区二区三区
|
狠狠综合久久综合88亚洲|
久久精品免费网站网|
亚洲&#228;v永久无码精品天堂久久|
亚洲va国产va天堂va久久|
久久99精品久久久大学生|
久久免费视频1|
2021国内久久精品|
久久强奷乱码老熟女网站|
国产成人精品综合久久久久|
伊人久久大香线蕉亚洲|