32bit-64bit

问题 I am creating a quite simple application which reads and display text files and search through them. I am asking myself if there is any interest for me to propose 32 and 64 bits version to the user. Is the difference only in having access to more memory heap size with the 64 bit version or is there any other interest ? Will a 32 bit compiled program work on a 64 bits JVM (I assume yes) 回答1: The only differences between 32-bit and 64-bit builds of any program are the sizes of machine words,

问题 I use around 15-20 legacy 32-bit C++ COM DLLs in my web app, some of these 32-bit DLLs have 3rd party dependencies which are further DLL's COM or native. I am considering moving to Windows Azure which I understand is a 64-bit platform. Can anyone advise whether my 32-bit DLLs will work? (I know that it is now possible to regsvr32 them). With a week or two’s work I could recompile my DLLs to 64-bit however this is not possible for the 3rd party dependencies as I don’t have the source. I

问题 I have a Java program uses some dlls. As these embeded dlls have to be built for a specific system architecture (32 or 64bits) I want to make a method/something that allow my program to switch between 32/64 bits version of dlls (or disable the library load if the program run on a 64 bits system) I hope there is a solution different from making two versions of the program Thanks in advance, Damien 回答1: Use system properties: if ("x86".equals(System.getProperty("os.arch"))) { // 32 bit } else

问题 We are doing some 32bit * 32bit multiplication using the following algorithm Let us we want to multiply a (32 bit) with b (32 bit), both signed, a = ah * 2^16 + al [ah - Higher 16 bits, al - Lower 16 bits] b = bh * 2^16 + bl [bh - Higher 16 bits, bl - Lower 16 bits] We are effectively doing Result = (al * bl) + (((ah * bl) + (al * bh)) * 2^16) + ((ah * bh) * 2 ^ 32) ~~~ My question, Is their any better way to do this? 回答1: In any mainstream compiler, the emulation of 64-bit ints on a 32-bit

问题 I'm struggling with a problem of how to determine the location of the 64-bit Program Files directory on 64-bit Windows Vista from a 32-bit application. Calls to SHGetKnownFolderPath(FOLDERID_ProgramFilesX64) do not return anything. The MSDN article KNOWNFOLDERID also states that this particular call with FOLDERID_ProgramFilesX64 is not supported for a 32-bit application. I would like to avoid as much as possible hardcoding the path to "C:\Program Files". Doing something like

问题 I really hope there is some help to get on this subject. Has anyone ever used lua in an application that needs to have both 32-bit and 64-bit support? We are currently transitioning to 64-bit but are having trouble with client compiled lua scripts that we can't recompile ourselves using the 64-bit version. So in effect we need to be able to load bytecode files compiled using 32-bit lua in a 64-bit application. When we try to do so we receive an error message: virtual machine mismatch in test

问题 Would anyone please give me ideas about forcing 64 bit jvm to run as 32-bit jvm? I need to write a jse desktop application for bluetooth connection. For that i need to implement Bluecove jar . It has 32-bit files only. So i included -D32 under VM arguments in eclipse pulsar. But still i am getting the same error that displayed before adding the argument: bluecove_x64.dll missing. I tried with -d32, and it showed me "unrecognized option: d32". And it seems like i should install a 32-bit jvm

问题 How do I change the JRE (for example, to go from a from 64bit to 32bit version) that is used to run ant from inside eclipse? 回答1: I am not sure that you can do that in a global way. However, it is possible to choose your JRE when you run Ant on a specific project: Go in the Properties of your project, then select Builders and Ant Builder . In the properties for this builder, go in the JRE tab, and choose an Separate JRE . Another solution is to specify the JRE used directly in your build.xml

问题 How do i detect the bitness (32-bit vs. 64-bit) of the Windows OS in VBScript? I tried this approach but it doesn't work; I guess the (x86) is causing some problem which checking for the folder.. Is there any other alternative? progFiles="c:\program files" & "(" & "x86" & ")" set fileSys=CreateObject("Scripting.FileSystemObject") If fileSys.FolderExists(progFiles) Then WScript.Echo "Folder Exists" End If 回答1: You can query the PROCESSOR_ARCHITECTURE . A described here, you have to add some

问题 I recently received a: ...relocation R_X86_64_32 against `a local symbol' can not be used when making a shared object; recompile with -fPIC error while trying to compile a program as a shared library. Now the solution to this is not too difficult (recompile all dependencies with -fPIC), but after some research it turns out that this problem is only present on x86-64 platforms. On 32bit any position dependent code can still be relocated by the dynamic loader. The best answer I could find is: