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Porting 32 bit C++ code to 64 bit - is it worth it? Why?

Asked 2009-09-25T23:24:49.160
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I am aware of some the obvious gains of the x64 architecture (higher addressable RAM addresses, etc)... but:

  • What if my program has no real need to run in native 64 bit mode. Should I port it anyway?
  • Are there any foreseeable deadlines for ending 32 bit support?
  • Would my application run faster / better / more secure as native x64 code?
c++ x86 64-bit x86-64 cpu-architecture
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One possible benefit I haven't seen mentioned yet is that it might uncover latent bugs. Once you port it to 64-bit, a number of changes are made. The sizes of some datatypes change, the calling convention changes, the exception handling mechanism (at least on Windows) changes.

All of this might lead to otherwise hidden bugs surfacing, which means that you can fix them.

Assuming your code is correct and bug-free, porting to 64-bit should in theory be as simple as flicking a compiler switch. If that fails, it is because you're relying on things not guaranteed by the language, and so, they're potential sources of errors.

answered 2009-09-26T09:57:27.190

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