similar to: [LLVMdev] We need better hashing

By the way, the reason I'm bringing this up is that a number of folks are currently working on optimizing the use of hash tables within LLVM's code base, and unless we can come up with a common hashing facility, there will be an increasing proliferation of cut & paste copies of hash functions. So feedback would be nice. On Tue, Feb 7, 2012 at 10:58 PM, Talin <viridia at

Here's my latest version of Hashing.h, which I propose to add to llvm/ADT. Comments welcome and encouraged. On Thu, Feb 9, 2012 at 11:23 AM, Talin <viridia at gmail.com> wrote: > By the way, the reason I'm bringing this up is that a number of folks are > currently working on optimizing the use of hash tables within LLVM's code > base, and unless we can come up with a

Jeffrey and I are working on future standard library functionality for hashing user defined types: http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2012/n3333.html I would much rather have an interface that is close to or mirrors this one. We already have some field experience with it, and using it in LLVM and Clang would provide more. Also, it would be possible to essentially share code

On Fri, Feb 17, 2012 at 1:53 AM, Chandler Carruth <chandlerc at google.com>wrote: > Jeffrey and I are working on future standard library functionality for > hashing user defined types: > > http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2012/n3333.html > > I would much rather have an interface that is close to or mirrors this > one. We already have some field

On Mon, Feb 13, 2012 at 1:22 AM, Jay Foad <jay.foad at gmail.com> wrote: > On 13 February 2012 00:59, Talin <viridia at gmail.com> wrote: > > Here's my latest version of Hashing.h, which I propose to add to > llvm/ADT. > > Comments welcome and encouraged. > > > /// Adapted from MurmurHash2 by Austin Appleby > > Just out of curiosity, why not

On Sat, Feb 06, 2010 at 04:51:15PM -0800, Chandler Carruth wrote: > While I've not reviewed the patch in too much detail, it looks > promising. Can you run some end-to-end benchmarks to make sure that > cache pressure in the full program or other variables not accounted > for in a micro-benchmark don't dominate performance? Specifically the > nightly tester includes a number

OK here's a patch with the latest, including unit tests. I've also tried to make the comments clear that this is intended for the case of "generic" key types, where you are either hashing multiple data types together, or you don't know in advance what the data type will be - for cases such as strings where a tailored algorithm is available, you should use that instead of

On Feb 13, 2012, at 2:00 AM, Talin wrote: > Just out of curiosity, why not MurmurHash3 ? This page seems to > suggest that #2 has some flaw, and #3 is better all round: > > https://sites.google.com/site/murmurhash/ > > The main reason is because there's no incremental version of 3. I think that that is a great reason. > LLVM's needs, on the other hand, are fairly

On Fri, Feb 17, 2012 at 1:32 AM, Chris Lattner <clattner at apple.com> wrote: > On Feb 17, 2012, at 12:26 AM, Talin wrote: > > OK here's a patch with the latest, including unit tests. I've also tried > to make the comments clear that this is intended for the case of "generic" > key types, where you are either hashing multiple data types together, or > you

On Feb 17, 2012, at 12:26 AM, Talin wrote: > OK here's a patch with the latest, including unit tests. I've also tried to make the comments clear that this is intended for the case of "generic" key types, where you are either hashing multiple data types together, or you don't know in advance what the data type will be - for cases such as strings where a tailored algorithm

Some additional info can be found at: http://murmurhash.googlepages.com/ http://en.wikipedia.org/wiki/MurmurHash http://www.codeproject.com/KB/recipes/hash_functions.aspx as well as in the patch description itself. Patch and benchmark attached. Gregory -------------- next part -------------- A non-text attachment was scrubbed... Name:

On Feb 7, 2010, at 1:03 PM, Gregory Petrosyan wrote: > On Sat, Feb 06, 2010 at 04:51:15PM -0800, Chandler Carruth wrote: >> While I've not reviewed the patch in too much detail, it looks >> promising. Can you run some end-to-end benchmarks to make sure that >> cache pressure in the full program or other variables not accounted >> for in a micro-benchmark don't

On 13 February 2012 00:59, Talin <viridia at gmail.com> wrote: > Here's my latest version of Hashing.h, which I propose to add to llvm/ADT. > Comments welcome and encouraged. > /// Adapted from MurmurHash2 by Austin Appleby Just out of curiosity, why not MurmurHash3 ? This page seems to suggest that #2 has some flaw, and #3 is better all round:

I'm trying to install llvm on my windows development box and hit a problem I'm using cygwin cygwin% gcc --version gcc (GCC) 3.4.4 (cygming special, gdc 0.12, using dmd 0.125) I downloaded both the top of tree via svn I ran ./configure make make[1]: Entering directory `/cygdrive/c/llvm/lib/Support' llvm[1]: Compiling APFloat.cpp for Debug build llvm[1]: Compiling APInt.cpp

Rubin, Norman wrote: > I'm trying to install llvm on my windows development box and hit a > problem > I'm using cygwin > cygwin% gcc --version > gcc (GCC) 3.4.4 (cygming special, gdc 0.12, using dmd 0.125) > > I downloaded both the top of tree via svn > I ran ./configure > make > > make[1]: Entering directory `/cygdrive/c/llvm/lib/Support' >

On Tue, Feb 14, 2012 at 2:44 AM, Chris Lattner <clattner at apple.com> wrote: > On Feb 13, 2012, at 2:00 AM, Talin wrote: >> >> Just out of curiosity, why not MurmurHash3 ? This page seems to >> suggest that #2 has some flaw, and #3 is better all round: >> >> https://sites.google.com/site/murmurhash/ >> > The main reason is because there's no

On Tue, Feb 14, 2012 at 2:44 AM, Chris Lattner <clattner at apple.com> wrote: > On Feb 13, 2012, at 2:00 AM, Talin wrote: > > Just out of curiosity, why not MurmurHash3 ? This page seems to >> suggest that #2 has some flaw, and #3 is better all round: >> >> https://sites.google.com/site/murmurhash/ >> >> The main reason is because there's no

I used to be able to build LLVM (from source) under Cygwin for llvm-2.2 and previous releases, but can't continue the trend since the release of LLVM 2.3. I have tried a wide variety of gcc compilers (gcc 3.4.4, 4.1.2, 4.2.4 and 4.3.2) on cygwin, they all fail at the same location: C:\cygwin\home\czhao\ResearchTools\LLVM\2.3\obj2.3>make make[1]: Entering directory

While I've not reviewed the patch in too much detail, it looks promising. Can you run some end-to-end benchmarks to make sure that cache pressure in the full program or other variables not accounted for in a micro-benchmark don't dominate performance? Specifically the nightly tester includes a number of real programs and machinery to measure total compile time. On Sat, Feb 6, 2010 at 7:09

On Mon, Feb 08, 2010 at 10:31:23AM -0800, Chris Lattner wrote: > On Feb 7, 2010, at 1:03 PM, Gregory Petrosyan wrote: > > >On Sat, Feb 06, 2010 at 04:51:15PM -0800, Chandler Carruth wrote: > >>While I've not reviewed the patch in too much detail, it looks > >>promising. Can you run some end-to-end benchmarks to make sure that > >>cache pressure in the