There are more situations that strength reduction can be applicable. Do we want to make the optimization a general solution or just keep it case by case?
Thanks, xiaofeng On Tue, Aug 5, 2008 at 3:11 PM, Aleksey Shipilev <[EMAIL PROTECTED]> wrote: > On Tue, Aug 5, 2008 at 8:03 AM, xiaoming gu <[EMAIL PROTECTED]> wrote: >> Hi, guys. The patch for harmony-5901 is ready. > At last! Thanks, Xioaming! > >> I compared the performance for all the 5 benchmarks in "Java vs. C >> benchmark" by Stefan Krause on my desktop >> workstation (Intel Core 2 Quad [EMAIL PROTECTED], 3.23G RAM, Windows XP SP2). >> With MUL/DIV replaced by shift, >> spectralnorm is improved more than 29% (from 450258 msec to 319578 msec) > Can you spend some time and measure how much boost there is, in case > your _manual_ change of MUL/DIV operations to shifts? I had measured > +60% boost, so it would be great to conclude whether yours +30% is > connected with patch overheads (handling negative operands, I guess) > or your environment. > > Thanks, > Aleksey. > -- http://xiao-feng.blogspot.com
