[LLVMdev] Architecture Dependency of LLVM bitcode (was Re: compile linux kernel)

Christian Plessl
Mon, 29 Sep 2008 13:18:44 -0000

On 29.09.2008, at 11:53, Jonathan S. Shapiro wrote:

> Watching this thread, it occurs to me that the "V" in
"LLVM" is
> creating
> confusion. So far as I know, LLVM is the first project to use
> "virtual"
> to refer to the instruction set of the intermediate form. I understand
> why this labeling made sense (sort of), but it was unfortunate. The
> machine is abstract, not virtual, and the use of "virtual" here
is so
> out of keeping with any other use of the term that it really does
> generate confusion.

The topic whether LLVM bitcode is independent of the target platform
was raised several times on the mailing list, but it was never
discussed in detail. I would appreciate learning more about the
following questions:

-  Is the architecture dependence of LLVM IR only an artifact of llvm-
gcc producing architecture dependent results?
- What architecture-specific features are present in the IR that
prevent running the same LLVM bitcode on different architectures?

> Is this worth a FAQ entry?


I would definitely appreciate such a FAQ entry.

Best regards,
  Christian