[PATCH] elfedit: add support for editing e_flags

[WANG Xuerui]

On 2023/3/2 16:20, Xi Ruoyao wrote:
> On Thu, 2023-03-02 at 16:01 +0800, WANG Xuerui wrote:
>
>> I have to pick up the work because I was trying to make AMDGPU DCN work
>> on LoongArch, but that piece of code requires hard-float support while
>> the LoongArch Linux kernel is compiled in the soft-float ABI, leading to
>> link-time failures intermixing the two.
> IMO we should keep soft-float ABI while enabling the FPU (i. e.
> -mabi=lp64s -mfpu=64).  But ouch, this does not work properly with
> current GCC...  -mfpu=64 silently enables using FPR to pass arg and
> return value, w/o even a warning.  Not sure about Clang.
>
> <rant>I remember I've been saying "floating ABI and floating instruction
> set should be de-coupled" multiple times: "I" in "ABI" stands for
> "interface" anyway and all the interfaces are just designed for hiding
> implementation details.  But it seems nobody took it seriously.</rant>

Yeah. I remember the Toolchain Conventions has similar words so I've 
immediately tried `-mdouble-float` without `-mabi=lp64d`, after seeing 
the rejected interlinks, only to see the ABI implicitly promoted to 
LP64D nevertheless...