Compile 32 bit binary on 64 bit system

Question

I've coded a Go program in a 64 bit system but I want to compile a 32 bit binary!

The 64 bit binary is working just great but I have no idea how to create a 32 bit binary.

How can I do it?

Answer 1

If you built your Go from source, then you can build any additional compilers and libraries for any CPU and OS. If you are on windows/amd64 and want to build for windows/386, then this will build everything you need to compile for windows/386:

set GOARCH=386   cd %GOROOT%\src   make.bat --no-clean   

Once you have done that, you can build your windows/386 executable with:

set GOARCH=386   cd %YOUR_PROG_DIR%   go build   

Since you are on windows/amd64, you should be able to even run / test your windows/386 programs too. Just make sure to set GOARCH=386 before you invoke any commands for windows/386.

One caveat: this does not support cgo, so you cannot use any packages that use cgo.

Answer 2

The way I have achieved this (without any compiling of the compiler) on my Windows 7 64 bit PC was first having the windows amd64 installed, then download 32bit zip and unpack to a second folder:

\go\go32 \go\go64 

By then adjusting the PATH and the GOROOT inside my command prompt window as follows:

set PATH=\go\go32;%PATH% set GOROOT=\go\go32\ 

Then I went back and recompiled my app that was previously compiling using the 64 bit. All this can be setup in a batch if you want to switch between regularly.