[LLVMdev] Memory models support (-mcmodel=large)

Dan Gohman gohman at apple.com
Mon Jun 8 12:07:41 PDT 2009

On Jun 7, 2009, at 10:38 AM, Andrea OrrĂ¹ wrote:

> Hello all,
> I'm developing a hobby kernel for x86-64 machines,
> and I put the kernel into the higher half.
> I'm trying to switch from GCC to LLVM/Clang, but it seems
> that the latter doesn't support the -mcmodel=large
> option, which is required in order to put the kernel
> at the 0xFFFF800000000000 address in virtual memory,
> as specified in my linker script:
> http://pastebin.com/f2f9e0112
> I've already posted in the Clang's mailing list, but it seems
> that the argument is passed to LLVM, so the front-end is OK.
> Any workarounds or plans for implementing that feature in LLVM?

There's some code in place, but it's not complete. It's waiting
for someone who needs the feature to step forward and finish it.


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