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SSE4 instructions
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Robert Hyatt



Joined: 27 Feb 2006
Posts: 15819
Location: Birmingham, AL
PostPost subject: Re: SSE4 instructions    Posted: Thu May 24, 2012 3:41 pm Reply to topic Reply with quote
Engin wrote:
i just wonder why my lookups are faster....


How are you testing? Your lookup table is 64kb, which is larger than Intel L1 data cache. If you just do repeated popcnt's on the same value, that test is worthless because you get the 4 entries needed loaded into L1. If you test on random 64 bit values, you get a better idea. But even that is not good enough, because that 64kb array will have to compete with all the OTHER data a real chess engine uses, which means that if even one of those accesses misses on L1 cache, you are immediately slower than a popcnt hardware instruction...
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Display posts from previous:   
Subject Author Date/Time
SSE4 instructions Maurizio Maglio Mon May 21, 2012 8:48 pm
      Re: SSE4 instructions Adam Hair Mon May 21, 2012 10:47 pm
            Re: SSE4 instructions Maurizio Maglio Tue May 22, 2012 7:47 am
      Re: SSE4 instructions Joona Kiiski Tue May 22, 2012 1:55 pm
            Re: SSE4 instructions Engin Üstün Tue May 22, 2012 8:11 pm
                  Re: SSE4 instructions Maurizio Maglio Tue May 22, 2012 8:41 pm
                  Re: SSE4 instructions Robert Hyatt Wed May 23, 2012 3:39 pm
      Re: SSE4 instructions Engin Üstün Tue May 22, 2012 7:31 pm
            Re: SSE4 instructions Engin Üstün Tue May 22, 2012 7:34 pm
                  Re: SSE4 instructions Ricardo Barreira Wed May 23, 2012 7:40 am
                        Re: SSE4 instructions Robert Hyatt Wed May 23, 2012 3:37 pm
                              Re: SSE4 instructions Richard Vida Wed May 23, 2012 5:28 pm
                                    Re: SSE4 instructions Robert Hyatt Wed May 23, 2012 5:47 pm
                                          Re: SSE4 instructions Ricardo Barreira Sat May 26, 2012 3:14 pm
                                    Re: SSE4 instructions Engin Üstün Wed May 23, 2012 10:02 pm
                                          Re: SSE4 instructions Vincent Diepeveen Thu May 24, 2012 12:02 am
                                                Re: SSE4 instructions Engin Üstün Thu May 24, 2012 3:54 pm
                                                      Re: SSE4 instructions Engin Üstün Thu May 24, 2012 4:07 pm
                                          Re: SSE4 instructions Lucas Braesch Thu May 24, 2012 11:03 am
                                          Re: SSE4 instructions Martin Sedlak Thu May 24, 2012 11:47 am
                                                Re: SSE4 instructions Vincent Diepeveen Thu May 24, 2012 12:35 pm
                                                      Re: SSE4 instructions Martin Sedlak Thu May 24, 2012 12:46 pm
                                                      Re: SSE4 instructions Engin Üstün Thu May 24, 2012 4:24 pm
                                    Re: SSE4 instructions Engin Üstün Thu May 24, 2012 4:41 pm
                        Re: SSE4 instructions Engin Üstün Wed May 23, 2012 4:35 pm
                              Re: SSE4 instructions Robert Hyatt Wed May 23, 2012 5:48 pm
                                    Re: SSE4 instructions Engin Üstün Wed May 23, 2012 10:28 pm
                                          Re: SSE4 instructions Robert Hyatt Thu May 24, 2012 3:41 pm
                                                Re: SSE4 instructions Engin Üstün Thu May 24, 2012 4:31 pm
                        Re: SSE4 instructions Engin Üstün Thu May 24, 2012 4:35 pm
      Re: SSE4 instructions Don Dailey Thu May 24, 2012 9:09 pm
            Re: SSE4 instructions Richard Vida Thu May 24, 2012 9:21 pm
                  Re: SSE4 instructions Vincent Diepeveen Fri May 25, 2012 12:19 am
                  Re: SSE4 instructions Engin Üstün Fri May 25, 2012 10:44 pm
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