[racket-dev] assembler code within gmplonglong.h
Hi. The last days I've been reading the code within gmplonglong.h and I've a question/request. Why there is assembler code? Why not just to remove the assembler code and to use the C fallback for every CPU?. These days the racket developers (and users) mostly only test their code on amd64, specially the math code. The file doesn't contain assembler code for amd64, so almost every one is compiling their interpreters with the C code. The old CPUs supported by gmplonglong.h are dead or have a modern C compiler. I doubt the assembler code even gives a better performance to racket than the C version. I'm complaining because I've tried to compile racket 5.3.6 (with some patches related to clang and gmp backported from the master branch) with clang and the build failed. I read the code and I was stunned when I saw the assembler code supporting so old CPUs and the C fallback used by amd64. _ Racket Developers list: http://lists.racket-lang.org/dev
[racket-dev] release notes draft
Below is the latest release notes draft. Comments? Robby Racket has a new package system, including a catalog of already available packages. Please visit http://pkgs.racket-lang.org/ for an overview. Recent releases included the beta versions of the package system. Racket version 6.0 incorporates many improvements suggested by these preliminary experiences: * A package is treated as a single collection by default, so it is even easier to use a Github repository as a package. Get started quickly: http://docs.racket-lang.org/pkg/getting-started.html * DrRacket includes a new package manager GUI, which is also available as a stand-alone program via the gui-pkg-manager package. * The main Racket distribution has been broken into about 200 packages. An installation starts with Minimal Racket and then adds these bundled packages. Alternatively, you may now install a Minimal Racket distribution --- which is about 1/10 the size of the main distribution --- and add only those packages that you need. * Package installation supports pre-built packages that include compiled byte code and rendered documentation, meaning packages can be installed quickly when built versions are a available. All packages in the main distribution are available in pre-built form. Further improvements are in the works, including package documentation on the package-catalog web site. COMPATIBILITY NOTE: PLaneT will remain in place for the foreseeable future, but we expect all package work to shift to the new system. Beyond the package system, this release brings a number of other changes: * Racket's HTML documentation has a new and improved look, thanks to Matthew Butterick. * Racket's JIT compiler supports the ARM architecture. * Racket supports the Mac's Retina display mode. * The profiler provides a new mode that uses the errortrace library to produce fine-grained profiles. * A new contract profiler reports how much time programs spend checking contracts, and which contracts are most expensive. * The math/flonum library exports fast 105-bit precision operations. * Check Syntax handles generated identifiers, especially those introduced by struct (e.g. field selectors) and Redex (e.g., e_1, e_2) * 2htdp/batch-io includes functions for dealing with html/xml in files and web sites as X-expressions plus conveniences for web-based graph traversals. _ Racket Developers list: http://lists.racket-lang.org/dev
Re: [racket-dev] assembler code within gmplonglong.h
On the program (time (for/fold ([v (for/fold ([v 1]) ([i (in-range 1)]) (* (add1 i) v))]) ([i (in-range 1)]) (/ v (add1 i when compiling for 32-bit x86 with the latest XCode's clang and using a 2013 MacBook Pro running Mavericks, I get a 50% speed decrease when disabling the assembly code in gmplonglong.h. So, at least for 32-bit x86, I think the assembly code is probably worthwhile. Assembly seems to matter less for 64-bit mode. I copied the x86_64 assembly from the current GMP, and it seems to improve performance by 10%. That's not much of a difference, but enough that I would be inclined add the assembly; I hesitate only because adding more assembly is exactly the opposite of your request. At Sun, 12 Jan 2014 01:31:21 +0100, Juan Francisco Cantero Hurtado wrote: Hi. The last days I've been reading the code within gmplonglong.h and I've a question/request. Why there is assembler code? Why not just to remove the assembler code and to use the C fallback for every CPU?. These days the racket developers (and users) mostly only test their code on amd64, specially the math code. The file doesn't contain assembler code for amd64, so almost every one is compiling their interpreters with the C code. The old CPUs supported by gmplonglong.h are dead or have a modern C compiler. I doubt the assembler code even gives a better performance to racket than the C version. I'm complaining because I've tried to compile racket 5.3.6 (with some patches related to clang and gmp backported from the master branch) with clang and the build failed. I read the code and I was stunned when I saw the assembler code supporting so old CPUs and the C fallback used by amd64. _ Racket Developers list: http://lists.racket-lang.org/dev _ Racket Developers list: http://lists.racket-lang.org/dev
Re: [racket-dev] assembler code within gmplonglong.h
I will give a try to your example. I disabled the assembler code in the OpenBSD port because with your last patch to gmplonglong and clang, the 5.3.6 math lib was broken on i386. We will have the CVS lock soon and I want be very careful now. I used initially clang to fix a crash in udp.rktl, now the port uses GCC 4.6. I will report both bugs when I have some of free time, if I can reproduce both with racket 6. It's OK if you want use assembler for the math code, I was just worried when I saw the amount of code for old CPUs, especially because I will work with some of these CPUs pretty soon and I fear there is more untested code for these archs. Compared with the usually elegant use of C macros in racket, that file is really hairy :) . And yes, 50% is a big difference, good to know :) . On 01/12/14 04:22, Matthew Flatt wrote: On the program (time (for/fold ([v (for/fold ([v 1]) ([i (in-range 1)]) (* (add1 i) v))]) ([i (in-range 1)]) (/ v (add1 i when compiling for 32-bit x86 with the latest XCode's clang and using a 2013 MacBook Pro running Mavericks, I get a 50% speed decrease when disabling the assembly code in gmplonglong.h. So, at least for 32-bit x86, I think the assembly code is probably worthwhile. Assembly seems to matter less for 64-bit mode. I copied the x86_64 assembly from the current GMP, and it seems to improve performance by 10%. That's not much of a difference, but enough that I would be inclined add the assembly; I hesitate only because adding more assembly is exactly the opposite of your request. At Sun, 12 Jan 2014 01:31:21 +0100, Juan Francisco Cantero Hurtado wrote: Hi. The last days I've been reading the code within gmplonglong.h and I've a question/request. Why there is assembler code? Why not just to remove the assembler code and to use the C fallback for every CPU?. These days the racket developers (and users) mostly only test their code on amd64, specially the math code. The file doesn't contain assembler code for amd64, so almost every one is compiling their interpreters with the C code. The old CPUs supported by gmplonglong.h are dead or have a modern C compiler. I doubt the assembler code even gives a better performance to racket than the C version. I'm complaining because I've tried to compile racket 5.3.6 (with some patches related to clang and gmp backported from the master branch) with clang and the build failed. I read the code and I was stunned when I saw the assembler code supporting so old CPUs and the C fallback used by amd64. _ Racket Developers list: http://lists.racket-lang.org/dev
