[x32] Allow R_X86_64_64

H.J. Lu hjl.tools@gmail.com
Fri Aug 12 12:10:00 GMT 2011


On Fri, Aug 12, 2011 at 12:30 AM, Jan Beulich <JBeulich@novell.com> wrote:
>>>> On 12.08.11 at 06:37, "H.J. Lu" <hjl.tools@gmail.com> wrote:
>> On Mon, Aug 1, 2011 at 3:15 PM, H.J. Lu <hjl.tools@gmail.com> wrote:
>>> Hi,
>>>
>>> It turns out that x32 needs R_X86_64_64.  One major reason is
>>> the displacement range of x32 is -2G to +2G.  It isn't a problem
>>> for compiler since only small model is required for x32.
>>>
>>> However, to address 0 to 4G directly in assembly code, we have
>>> to use R_X86_64_64 with movabs.  I am checking the follow patch
>>> into x32 psABI to allow R_X86_64_64.
>>>
>>>
>>
>> X32  Linker should treats R_X86_64_64 as R_X86_64_32
>> zero-extended to 64bit for output.  I will update x32 psABI with
>
> I'm sorry to say that, but the situation about x32 seems to be
> getting worse with each change you do, every time again
> revolving around mixing up ABI specification and a particular
> implementation thereof.
>
> Here, if you need something zero-extended (though I can't see
> why you would), then you should use a new relocation type. As
> pointed out before, there are valid possible uses of R_X86_64_64
> that would require the semantics of x86-64.
>

When does x32 need the semantics of x86-64 for R_X86_64_64?
No, you can't mix ELF32 with ELF64.

-- 
H.J.



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