Re: [4.4] Strange performance regression?

2009-10-14 Thread francesco biscani
Hi Joern and list(s), On Wed, Oct 14, 2009 at 12:05 PM, Joern Rennecke wrote: > He also said that it was a different machine, Core 2 Q6600 vs > some kind of Xeon Core 2 system with a total of eight cores. > As different memory subsystems are likely to affect the code, it > is not an established r

Re: [4.4] Strange performance regression?

2009-10-14 Thread Tim Prince
Joern Rennecke wrote: Quoting Mark Tall : Joern Rennecke wrote: But at any rate, the subject does not agree with the content of the original post. When we talk about a 'regression' in a particular gcc version, we generally mean that this version is in some way worse than a previous version of

Re: [4.4] Strange performance regression?

2009-10-14 Thread Joern Rennecke
Quoting Mark Tall : Joern Rennecke wrote: But at any rate, the subject does not agree with the content of the original post. When we talk about a 'regression' in a particular gcc version, we generally mean that this version is in some way worse than a previous version of gcc. Didn't the orig

Re: [4.4] Strange performance regression?

2009-10-13 Thread Mark Tall
Joern Rennecke wrote: > But at any rate, the subject does not agree with > the content of the original post. When we talk > about a 'regression' in a particular gcc version, > we generally mean that this version is in some > way worse than a previous version of gcc. Didn't the original poster ind

Re: [4.4] Strange performance regression?

2009-10-13 Thread Ian Lance Taylor
Joern Rennecke writes: > Quoting Ian Lance Taylor : > >> francesco biscani writes: >> >>> I'm experiencing a strange behaviour with GCC 4.4.1. Basically I have >>> some C++ mathematical code which gets a ~x2 performance drop if I >>> *remove* the following debug line from the code: >> >> >> This

Re: [4.4] Strange performance regression?

2009-10-13 Thread Joern Rennecke
Quoting Ian Lance Taylor : francesco biscani writes: I'm experiencing a strange behaviour with GCC 4.4.1. Basically I have some C++ mathematical code which gets a ~x2 performance drop if I *remove* the following debug line from the code: This message is not appropriate for the mailing list

Re: [4.4] Strange performance regression?

2009-10-13 Thread Ian Lance Taylor
francesco biscani writes: > I'm experiencing a strange behaviour with GCC 4.4.1. Basically I have > some C++ mathematical code which gets a ~x2 performance drop if I > *remove* the following debug line from the code: This message is not appropriate for the mailing list g...@gcc.gnu.org. It is a

[4.4] Strange performance regression?

2009-10-13 Thread francesco biscani
Hi list, I'm experiencing a strange behaviour with GCC 4.4.1. Basically I have some C++ mathematical code which gets a ~x2 performance drop if I *remove* the following debug line from the code: --- std::cout << "Block size: " << block_size << '\n'; --- Where block_size