I develop and run some Fortran Code under Windows (7, 64 bit) using Visual Studio 2010 and ifort.
The code, mostly compiled to a DLL file, is tested on Windows and is deployed approx. 25% of the time to Windows (Windows 2000 up to Windows 7) and 75% to SUSE Linux. While the Windows solution is completely handled by me, the Linux "branch" is compiled by someone other (it is 100% the same code). The Linux branch is compiled with the g95/NAG compiler.
Due to some decisions out of our control, we will change from NAG to gfortran. After some tests, we found the code compiled with gfortran (and some optimisation like -o2) to take about double the time to finish compared to Windows and ifort (no optimisation, full debug). We had a chance to compile the code under Linux and ifort and got about the speed of Windows + ifort. (NAG compiled code is somewhere in between.)
For obvious reasons, we would like to compile the code with ifort for Windows and Linux, so:
Is it possible to compile for SUSE Linux under Windows with ifort (using cmd or Visual Studio 2010)?
I'll answer for Intel - no, you can't compile for Linux in Windows (except using a VM in which case you are really running Linux, as stated above). A VM is a reasonable approach, but you'll have to buy a separate license for ifort on Linux.
Or, as I assume you have a Linux box you will test on, build there (you can SSH to it from your Windows box.) True, you won't have the Visual Studio IDE, but some of our customers use Eclipse (with the Photran plugin) or Code::Blocks with Intel Fortran.
Related
I have a VM running CentOs Linux on my Windows 10 machine. Yesterday I built the GCC from source, and saw an option where you could build it to cross compile. My question is this: is it possible (and if it is, how is it done), to compile GCC so that it is capable of building Windows executables on Linux (that I can then run on my computer)? I would like to avoid using MinGW if at all possible so that I won't have to use the special libraries.
I am working on a project where I have to compile a program which is to run on Windows 7 computers. I only have a Linux computer, so I borrow a friends computer to compile the program before emailing it to the client. Then the client comes back to me with requested alterations, etc.
Can I compile the program for Windows using gcc/g++ for Linux?
try MingW http://www.mingw.org/. perhaps it solve your problem
I wrote an application in C++ for linux (X11, GLX) and it is working alright on my development computer (32-bit linux on 64-bit capable hardware). However, when I ran it on a 64-bit linux downstairs, I received an error telling me the linker failed to link stdlibc++.so.6, but I thought 32-bit compiled application could run on 64-bit kernels and Oses as well? At least that is the case in Windows... Do I have to separately compile 32 and 64 bit with different libs?
And how do I properly distribute my application? It's a game, and currently you have to run a makefile to let it move its dependencies to the /usr/lib/ directory (a kind of amateur installer). Will this work on all mainstream linux distro's? And are there better, neater ways to release your application?
I am developing a software in C++ on windows 32-bit (using MSVC++), but since I want to be able to use my software on every platform, I have decided to use CMake as my build generator.
Therefore, I am still just a beginner in CMake. From the CMake tutorials, I understand that in order to cross compile codes, first a toolchain simulating the target platform should be installed on the host platform. Then using the appropriate target-platform C and C++ compilers provided by this toolchain, CMake would be able to generate makefiles etc.
Now, I want to build my code for Linux platform(GNU/Linux) on a Win32 platform. I tried doing the above procedure using CMake combined with Cygwin and using gcc and g++ as compilers. It built fine, created makefiles, and when I issued "make" in Cygwin terminal, the generated makefiles were "made". Now I have got an executable which I was hoping would run on Linux platform. But on Linux I get the error: bash cannot execute binary file.
Using command file executablename, I realized the executable which is made by the above procedure is of type PE32 which is only for Windows.
Now my question is: Is my understanding of cross-platform build procedure using cmake correct?Or should I just use another Linux toolchain under windows to get a Linux ELF executable? What toolchains come to your mind which would give me what I want?
Many thanks
Setareh
You will want to look here: cmake-toolchains(7) if you do cross compiling. However, I would suggest that you install a Linux VM like virtual box on your windows machine and build naively on Linux. It will compile much faster and you will not have to worry about cross compiling. You can mount the windows disk from the linux VM so you can share the same source tree. The linux VM will compile much faster than gcc running under windows.
Your understanding of CMake is correct... it will determine how to create the build system you request (or is default for the platform you are currently on) based on rules in your CMakeLists.txt file. However, this won't necessarily help you compile for linux on a windows machine if you don't have something installed that can target linux.
To compile targeting linux, you will need to use a linux compiler. The link posted by #stjin tells you how to install one on cygwin. Then, to set up your CMake build, do this in the terminal:
CC=gcc-linux CXX=g++-linux cmake . [options]
This will tell CMake to locate the special linux targeted compilers. Hopefuly, after compiling with these compilers you will be able to run on linux.
When compiling code with VC++, MSDN gives you the option between using the x86_amd64 toolset or the amd64 toolset (when calling vcvarsall.bat).
How do I choose between those two when compile x64 code? Will the amd64 option churn out more efficient x64 machine code than the cross compiler?
It has nothing to do with efficiency. The native and cross-compiler will both generate the same machine code. You will however gain some benefits by running a native 64-bit compiler process on a 64-bit workstation (larger registers, larger memory space, etc...).
The native compiler will only run on an 64-bit copy of Windows, so if your workstation is 32-bit this compiler won't even run.
The cross-compiler is meant to run on x86 machines even though it will run on a 64-bit copy of Windows via WoW; however, there is no reason to do this.
The page you link says it quite well:
x64 on x86 (x64 cross-compiler)
Allows
you to create output files for x64.
This version of cl.exe runs as a
32-bit process, native on an x86
machine and under WOW64 on a 64-bit
Widows operating system.
x64 on x64
Allows you to create output
files for x64. This version of cl.exe
runs as a native process on an x64
machine.
Thanks to Brian R. Bondy for the quote formatting
From what you linked:
x64 on x86 (x64 cross-compiler)
Allows
you to create output files for x64.
This version of cl.exe runs as a
32-bit process, native on an x86
machine and under WOW64 on a 64-bit
Widows operating system.
x64 on x64
Allows you to create output
files for x64. This version of cl.exe
runs as a native process on an x64
machine.
Paraphrased:
If you use x86_amd64, then you are typically developing on an x86 machine and you want to create x64 files that run natively on x64. You could also use this option on an x64 machine but your compiler will be running under WOW64 emulation.
If you use AMD64, then you are developing on an x64 machine and you want to create x64 files that run natively on x64. The compiler is running natively in x64. This option is more efficient to build x64 programs.
You may wonder why you would ever develop an x64 program on an x86 computer, since you can't run it you can't debug it. Well it's still useful for example if you have a build server which is x86 and that build server needs to generate both x86 and x64 outputs.
How is it possible for a compiler to run under x64 if it is an x86 based program (x86_amd64)? That is the same reason you can run any x86 program on your x64 machine... Thanks to WOW64 emulation.
What is WOW64 emulation:
WOW64 emulation happens when you run an x86 program on an x64 computer (or IA64). WOW64 stands for Windows 32 on Windows 64. It is an emulation layer on top of x64 machines which allow you to execute x86 programs.
Your file system operations will be redirected to WOW64 folders and your registry will be redirected to a subnode as well. For example when you try to obtain the folder for program files it will return c:\program files (x86)\ if you are using WOW64 but it will return c:\program files\ if you are using x64.
Another example, for the registry if you try to write to HKLM\Software\Something it will really redirect you to HKLM\SOFTWARE\Wow6432Node\Something without your x86 program's knowledge.
Running a native x64 build will be more efficient than running through WOW64 emulation Why? Because you don't have that extra emulation layer of transforming your 32bit calls into 64bit ones.
By the way if you are running the x64 version of Windows you can see which processes are running through WOW64 because they will have a *32 appended to the process name in the process list.