Re: Performance: switch vs if ... else if

2009-05-22 Thread Christopher Schultz
-BEGIN PGP SIGNED MESSAGE- Hash: SHA1 David, On 5/21/2009 1:57 PM, David kerber wrote: Interesting. From that description, depending on how sparse is sparse, there's probably a good chance I'm getting a tableswitch. If you find that a tableswitch is /not/ being generated, you could

RE: Performance: switch vs if ... else if

2009-05-22 Thread Caldarale, Charles R
From: Christopher Schultz [mailto:ch...@christopherschultz.net] Subject: Re: Performance: switch vs if ... else if If you find that a tableswitch is /not/ being generated, The tableswitch is being generated for the enum switch (rtFields), but not the char switch. However, using the enum

Re: Performance: switch vs if ... else if

2009-05-22 Thread David kerber
Caldarale, Charles R wrote: From: Christopher Schultz [mailto:ch...@christopherschultz.net] Subject: Re: Performance: switch vs if ... else if If you find that a tableswitch is /not/ being generated, The tableswitch is being generated for the enum switch (rtFields), but not the char

RE: Performance: switch vs if ... else if

2009-05-22 Thread Peter Crowther
From: David kerber [mailto:dcker...@verizon.net] As a result, right now I don't have any way of generating enough load to find a bottleneck in the overall servlet (which is a very good thing!!). That's a win. Congratulations! - Peter

Re: Performance: switch vs if ... else if

2009-05-21 Thread Christopher Schultz
-BEGIN PGP SIGNED MESSAGE- Hash: SHA1 David, On 5/19/2009 3:04 PM, David kerber wrote: I have a section of code in a frequently-called (~3.5 million times per day) servlet where I had to process based on a parameter that could take one of 6 different single-character string values. I

Re: Performance: switch vs if ... else if

2009-05-21 Thread David kerber
Christopher Schultz wrote: -BEGIN PGP SIGNED MESSAGE- Hash: SHA1 David, On 5/19/2009 3:04 PM, David kerber wrote: I have a section of code in a frequently-called (~3.5 million times per day) servlet where I had to process based on a parameter that could take one of 6 different

RE: Performance: switch vs if ... else if

2009-05-21 Thread Caldarale, Charles R
From: David kerber [mailto:dcker...@verizon.net] Subject: Re: Performance: switch vs if ... else if Can you point me to a byte code interpreter so I could look at this? The javap tool in the JDK will display the byte codes. (I use it a lot.) If you want, go ahead and send me the class

Re: Performance: switch vs if ... else if

2009-05-20 Thread Ronald Klop
21:51 schreef David kerber : Caldarale, Charles R wrote: From: David kerber [mailto:dcker...@verizon.net] Subject: Performance: switch vs if ... else if I had to process based on a parameter that could take one of 6 different single-character string values. I had been using an if .. else

Re: Performance: switch vs if ... else if

2009-05-20 Thread David kerber
Ronald Klop wrote: As with the tips about usage of char in the switch you can also test using a char in the if ... else. if (myChr.length() != 1) { throw new RuntimeException(invalid length); } char ch = myChr.charAt(0); if (ch == 'c') { p += 1; } else if (ch == 'r') { p += 2; } ...

Performance: switch vs if ... else if

2009-05-19 Thread David kerber
This isn't directly related to tomcat, but does relate to the performance testing people have done over the last couple of days. I have a section of code in a frequently-called (~3.5 million times per day) servlet where I had to process based on a parameter that could take one of 6 different

RE: Performance: switch vs if ... else if

2009-05-19 Thread Caldarale, Charles R
From: David kerber [mailto:dcker...@verizon.net] Subject: Performance: switch vs if ... else if I had to process based on a parameter that could take one of 6 different single-character string values. I had been using an if .. else if construct. Interesting numbers. Can you show us

Re: Performance: switch vs if ... else if

2009-05-19 Thread David kerber
Caldarale, Charles R wrote: From: David kerber [mailto:dcker...@verizon.net] Subject: Performance: switch vs if ... else if I had to process based on a parameter that could take one of 6 different single-character string values. I had been using an if .. else if construct. Interesting

Re: Performance: switch vs if ... else if

2009-05-19 Thread George Sexton
If you're only doing a single character, you would probably get better performance with: switch (sString.char(0)) { case 'A': case 'B': case 'C': } David kerber wrote: Caldarale, Charles R wrote: From: David kerber [mailto:dcker...@verizon.net] Subject: Performance: switch vs

Re: Performance: switch vs if ... else if

2009-05-19 Thread Konstantin Kolinko
2009/5/19 David kerber dcker...@verizon.net: Caldarale, Charles R wrote: From: David kerber [mailto:dcker...@verizon.net] Subject: Performance: switch vs if ... else if I had to process based on a parameter that could take one of 6 different single-character string values.  I had been

Re: Performance: switch vs if ... else if

2009-05-19 Thread David kerber
Konstantin Kolinko wrote: 2009/5/19 David kerber dcker...@verizon.net: Caldarale, Charles R wrote: From: David kerber [mailto:dcker...@verizon.net] Subject: Performance: switch vs if ... else if I had to process based on a parameter that could take one of 6 different single-character

Re: Performance: switch vs if ... else if

2009-05-19 Thread David kerber
Konstantin Kolinko wrote: ... 1. If you are doing tests with the classic VM, allow it some time to warmup and compile your code. That is, run the same test first with a smaller count of iterations. Server VM precompiles code before using it, while Classic one compiles heavily used parts of

RE: Performance: switch vs if ... else if

2009-05-19 Thread Caldarale, Charles R
From: Konstantin Kolinko [mailto:knst.koli...@gmail.com] Subject: Re: Performance: switch vs if ... else if Server VM precompiles code before using it, while Classic one compiles heavily used parts of code on-the-fly. Your terminology is incorrect, as are your descriptions of when code

Re: Performance: switch vs if ... else if

2009-05-19 Thread Konstantin Kolinko
2009/5/20 Caldarale, Charles R chuck.caldar...@unisys.com: From: Konstantin Kolinko [mailto:knst.koli...@gmail.com] Subject: Re: Performance: switch vs if ... else if Server VM precompiles code before using it, while Classic one compiles heavily used parts of code on-the-fly. Your

RE: Performance: switch vs if ... else if

2009-05-19 Thread Caldarale, Charles R
From: Konstantin Kolinko [mailto:knst.koli...@gmail.com] Subject: Re: Performance: switch vs if ... else if Regarding Server VM: I accept it as my mistake. I know, that Client VM is optimized for faster startup (and, well, it is written in the FAQ [1]), but I do not know why I thought