How can I tell if the JVM in which my application runs is 32 bit or 64-bit?  Specifically, what functions or properties I can used to detect this within the program?

How can I tell if I&#39;m running in 64-bit JVM or 32-bit JVM (from within a program)?

I&#39;m calling functions from a 32-bit unmanaged DLL on a 64-bit system. What I get is:

&gt; BadImageFormatException: An attempt was made to load a program with an incorrect format. (Exception from HRESULT: 0x8007000B)

At first, I had my projects set to the Any CPU platform, so I changed them both to x86, but this error is still occurring. That&#39;s really the only fix I know for this.

The DLLs aren&#39;t corrupt or anything, because I can use them with other programs (that I don&#39;t have the source to). I thought that perhaps it wasn&#39;t finding a dependency, but I checked and they&#39;re all there. Plus, wouldn&#39;t it throw a `DllNotFoundException` in that case?

What else can I do? And before you say &quot;Use a 64-bit unmanaged DLL instead,&quot; let me point out that there isn&#39;t one. ;)

&quot;An attempt was made to load a program with an incorrect format&quot; even when the platforms are the same

Is it possible to compile a project in **32-bit** with `cmake` and `gcc` on a **64-bit** system? It probably is, but how do I do it?

When I tried it the &quot;ignorant&quot; way, without setting any parameters/flags/etc, just setting `LD_LIBRARY_PATH` to find the linked libraries in `~/tools/lib` it seems to ignore it and only look in subdirectories named _lib64_.

How to compile a 32-bit binary on a 64-bit linux machine with gcc/cmake

I have a c# unit test project that is compiled for AnyCPU. Our build server is a 64bit machine, and has a 64bit SQL Express instance installed.

The test project uses code similar to the following to identify the path to the .MDF files:

    private string GetExpressPath()
    {
        RegistryKey sqlServerKey = Registry.LocalMachine.OpenSubKey( @&quot;SOFTWARE\Microsoft\Microsoft SQL Server\Instance Names\SQL&quot; );
        string sqlExpressKeyName = (string) sqlServerKey.GetValue( &quot;SQLEXPRESS&quot; );
        RegistryKey sqlInstanceSetupKey = sqlServerKey.OpenSubKey( sqlExpressKeyName + @&quot;\Setup&quot; );
        return sqlInstanceSetupKey.GetValue( &quot;SQLDataRoot&quot; ).ToString();
    }

This code works fine on our 32bit workstations, and did work ok on the build server until I recently enabled code coverage analysis with NCover. Because NCover uses a 32bit COM component, the test runner (Gallio) runs as a 32bit process.

Checking the registry, there is no &quot;Instance Names&quot; key under 

&gt; HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\Microsoft\Microsoft SQL Server

Is there a way for an application running in 32bit mode to access the registry outside  Wow6432Node?

Reading 64bit Registry from a 32bit application

I am trying to adapt an existing code to a 64 bit machine. The main problem is that in one function, the previous coder uses a void* argument that is converted into suitable type in the function itself. A short example:

    void function(MESSAGE_ID id, void* param)
    {
        if(id == FOO) {
            int real_param = (int)param;
            // ...
        }
    }

Of course, on a 64 bit machine, I get the error:

    error: cast from &#39;void*&#39; to &#39;int&#39; loses precision

I would like to correct this so that it still works on a 32 bit machine and as cleanly as possible. Any idea ?


Converting a pointer into an integer

Will Java code built and compiled against a 32-bit JDK into 32-bit byte code work in a 64-bit JVM?  Or does a 64-bit JVM require 64-bit byte code?

To give a little more detail, I have code that was working in a Solaris environment running a 32-bit JVM, but now I&#39;m getting issues after upgrading the JDK and Weblogic Server to 64-bit.

Java 32-bit vs 64-bit compatibility

When running a PowerShell script on a x64-bit OS platform, how can you determine _in the script_ what version of PowerShell (32-bit or 64-bit) the script is running on?  

**Background**  
Both 32-bit and 64-bit versions of PowerShell are installed by default on a 64-bit platform such as Windows Server 2008.  This can lead to difficulties when a PowerShell script is ran that must target a specific architecture (i.e. using 64-bit for a script for SharePoint 2010, in order to consume the 64-bit libraries).

Related question: 

 - [What is the best way to program against powershell&#39;s x64 vs. x86 variability?](https://stackoverflow.com/questions/602060/what-is-the-best-way-to-program-against-powershells-x64-vs-x86-variability) This question deals with code running against both 32-bit and 64-bit architectures.  My question deals with the case when you want to ensure the script only runs against the correct version.



Determine if current PowerShell Process is 32-bit or 64-bit?

I suppose I am focussing on x86, but I am generally interested in the move from 32 to 64 bit.

Logically, I can see that constants and pointers, in some cases, will be larger so programs are likely to be larger. And the desire to allocate memory on word boundaries for efficiency would mean more white-space between allocations.

I have also heard that 32 bit mode on the x86 has to flush its cache when context switching due to possible overlapping 4G address spaces.

So, what are the real benefits of 64 bit?

And as a supplementary question, would 128 bit be even better? 

Edit:

I have just written my first 32/64 bit program. It makes linked lists/trees of 16 byte (32b version) or 32 byte (64b version) objects and does a lot of printing to stderr - not a really useful program, and not something typical, but it is my first.
 
Size: 81128(32b) v 83672(64b) - so not much difference

Speed: 17s(32b) v 24s(64b) - running on 32 bit OS (OS-X 10.5.8)

Update:

I note that a new hybrid x32 ABI (Application Binary Interface) is being developed that is 64b but uses 32b pointers. For some tests it results in smaller code and faster execution than either 32b or 64b. 

https://sites.google.com/site/x32abi/



Are 64 bit programs bigger and faster than 32 bit versions?

The Windows operating system can be either 32 bit or 64 bit. The **64 bit** version is called **Windows x64** but the **32 bit** version is called **Windows x86**. Why isn&#39;t it called **Windows x32**? What is the reason?

Why is Windows 32-bit called Windows x86 and not Windows x32?

I&#39;ve got a proprietary program that I&#39;m trying to use on a 64 bit system. 

When I launch the setup it works ok, but after it tries to update itself and compile some modules and it fails to load them. 

I&#39;m suspecting it&#39;s because it&#39;s using gcc and gcc tries to compile them for a 64 bit system and therefore this program cannot use these modules.

Is there any way (some environmental variables or something like that) to force gcc to do everything for a 32 bit platform. Would a 32 bit chroot work?

Force gcc to compile 32 bit programs on 64 bit platform

I study the Linux kernel and found out that for x86_64 architecture the interrupt `int 0x80` doesn&#39;t work for calling system calls&lt;sup&gt;1&lt;/sup&gt;.

**For the i386 architecture (32-bit x86 user-space), what is more preferable: `syscall` or `int 0x80` and why?**

I use Linux kernel version 3.4.

---

Footnote 1: `int 0x80` does work in some cases in 64-bit code, but is never recommended.  https://stackoverflow.com/questions/46087730/what-happens-if-you-use-the-32-bit-int-0x80-linux-abi-in-64-bit-code



What is better &quot;int 0x80&quot; or &quot;syscall&quot; in 32-bit code on Linux?

How do I tell if my application (compiled in Visual&amp;nbsp;Studio&amp;nbsp;2008 as *Any CPU*) is running as a 32-bit or 64-bit application?


How do I tell if my application is running as a 32-bit or 64-bit application?

I think the question is self explanatory, I guess it probably has something to do with overflow but still I do not quite get it. What is happening, bitwise, under the hood?

Why does `-(-2147483648) = -2147483648` (at least while compiling in C)?

Why is -(-2147483648) = - 2147483648 in a 32-bit machine?

I&#39;m trying to compile a 32-bit C application on Ubuntu Server 12.04 LTS 64-bit using gcc 4.8. I&#39;m getting linker error messages about incompatible libraries and `skipping -lgcc`. What do I need to do to get 32 bit apps compiled and linked? 

How to Compile 32-bit Apps on 64-bit Ubuntu?

I have a text file that ends with .vbs that I have written the following in:

    Set Conn = CreateObject(&quot;ADODB.Connection&quot;)
    Conn.Provider = &quot;Microsoft.ACE.OLEDB.12.0&quot;
    Conn.Properties(&quot;Data Source&quot;) = &quot;C:\dummy.accdb&quot;
    Conn.Properties(&quot;Jet OLEDB:Database Password&quot;) = &quot;pass&quot;
    Conn.Open
    Conn.Close
    Set Conn = Nothing

- When I execute this on a Windows 32-bit machine it runs and ends without any notion (expected). 
- When I execute this on a Windows 64-bit machine it gets the error 
  &gt; Provider cannot be found. It may not be properly installed.

But it is installed. I think the root of the problem is that the provider is a 32-bit provider, as far as I know it doesn&#39;t exist as 64-bit.

If I run the VBScript through IIS on my 64-bit machine (as a ASP file) I can select that it should run in 32-bit mode. It can then find the provider.

How can I make it find the provider on Windows 64-bit? Can I tell CScript (which executes the .vbs text file) to run in 32-bit mode somehow?

How do I run a VBScript in 32-bit mode on a 64-bit machine?

Our C++ library currently uses time_t for storing time values. I&#39;m beginning to need sub-second precision in some places, so a larger data type will be necessary there anyway. Also, it might be useful to get around the Year-2038 problem in some places. So I&#39;m thinking about completely switching to a single Time class with an underlying int64_t value, to replace the time_t value in all places.

Now I&#39;m wondering about the performance impact of such a change when running this code on a 32-bit operating system or 32-bit CPU. IIUC the compiler will generate code to perform 64-bit arithmetic using 32-bit registers. But if this is too slow, I might have to use a more differentiated way for dealing with time values, which might make the software more difficult to maintain.

What I&#39;m interested in:

* which factors influence performance of these operations? Probably the compiler and compiler version; but does the operating system or the CPU make/model influence this as well? Will a normal 32-bit system use the 64-bit registers of modern CPUs?
* which operations will be especially slow when emulated on 32-bit? Or which will have nearly no slowdown?
* are there any existing benchmark results for using int64_t/uint64_t on 32-bit systems?
* does anyone have own experience about this performance impact?

I&#39;m mostly interested in g++ 4.1 and 4.4 on Linux 2.6 (RHEL5, RHEL6) on Intel Core 2 systems; but it would also be nice to know about the situation for other systems (like Sparc Solaris + Solaris CC, Windows + MSVC).

what is the performance impact of using int64_t instead of int32_t on 32-bit systems?

I have been trying to read up on 32-bit and 64-bit processors ([http://en.wikipedia.org/wiki/32-bit_processing][1]). My understanding is that a 32-bit processor (like x86) has registers 32-bits wide. I&#39;m not sure what that means. So it has special &quot;memory spaces&quot; that can store integer values up to 2^32?

I don&#39;t want to sound stupid, but I have no idea about processors. I&#39;m assuming 64-bits is, in general, better than 32-bits. Although my computer now (one year old, Win 7, Intel Atom) has a 32-bit processor. 


  [1]: http://en.wikipedia.org/wiki/32-bit_processing

What is the difference between a 32-bit and 64-bit processor?

What is the best 32bit hash function for relatively short strings?

Strings are tag names that consist of English letters, numbers, spaces and some additional characters (`#`, `$`, `.`, ...). For example: `Unit testing`, `C# 2.0`.

I am looking for &#39;best&#39; as in &#39;minimal collisions&#39;, performance is not important for my goals.

What is the best 32bit hash function for short strings (tag names)?

I just installed eclipse, the android sdk and jdk on a fresh installation for 64 bit fedora 14 , but by the time i create a new project i am getting the following error in the console:

&gt; android-sdks/build-tools/17.0.0/aapt: error while loading shared
&gt; libraries: libz.so.1: cannot open shared object file: No such file or
&gt; directory

i am using a 64bit machine and i need to install some 32bit drivers,
so i am trying to install: 

&gt; sudo apt-get install ia32-libs Reading Package Lists... Done Building
&gt; Dependency Tree... Done E: Couldn&#39;t find package ia32-libs

Anyone help me how to resolve 64bit fedora 14 machine libz.so.1 problems

android-sdks/build-tools/17.0.0/aapt: error while loading shared libraries: libz.so.1: cannot open shared object file: No such file or directory

During installation with an NSIS installer, I need to check which JRE (32bit vs 64bit) is installed on a system. I already know that I can check a system property &quot;`sun.arch.data.model`&quot;, but this is Sun-specific. I&#39;m wondering if there is a standard solution for this.


All 32 Bit Solutions on Gang of Coders

Total of 20 32 Bit Solutions

How can I tell if I'm running in 64-bit JVM or 32-bit JVM (from within a program)?

"An attempt was made to load a program with an incorrect format" even when the platforms are the same