Re: [Patch][GCN] [GCC 11] Backport GCN with LLVM-MC 13 linker fixes to GCC 11

[Andrew Stubbs <ams@codesourcery.com>]

This is fine by me.

As I said in my email on the 15th, LLVM 13 is still not considered safe 
to use. The ICE you encountered is a real problem that will affect real 
users.

I expect to work on a solution for that soon.

Andrew

On 16/10/2021 21:41, Tobias Burnus wrote:
> This patch is mostly motivated by distribution needs in general
> and Debian/Ubuntu needs in particular – but I think it makes
> sense for all GCC 11 users.
> 
> GCC's AMD GCN support uses LLVM's assembler and linker mc/lld
> and thus requires compatibility with LLVM. On mainline, support
> for LLVM 13 was added – and I like to see a backport to GCC 11.
> 
> In particular, I would like to "git cherry-pick -x' the following patches:
> 
> cfa1f8226f2 gcc/configure.ac: fix register issue for global_load 
> assembler functions
> aad32a00b7d amdgcn: Add -mxnack and -msram-ecc [PR 100208]
> 5c127c4cac3 amdgcn: Mark s_mulk_i32 as clobbering SCC
>   (Outside of this series as it only picks a bug fix)
> 6ca03ca35a5 amdgcn: Support LLVM 13 assembler syntax
>   (-> see remark below)
> 205dafb6ede amdgcn: Implement -msram-ecc=any
> 81c362c7c2b amdgcn: Fix assembler version incompatibility
> f3d64372d77 amdgcn: fix up offload debug linking with LLVM 13
> 
> OK for GCC 11?
> 
> [I have build GCC x86-64 with amdgcn offloading enabled both
> with LLVM 9 and with LLVM 13; libgomp passes fine with LLVM 9
> but with the LLVM 13 build, I see an ICE in lld for some testcases,
> which I have not debugged – but GCC itself builds and several
> libgomp testcases do pass.]
> 
> Tobias
> 
> PS: I attached
> * the full "git log --stat" for all those patches for references
> * as the 4th one, "Support LLVM 13 assembler syntax", does not
>    cleanly apply, I attached the full patch.
> 
> The reason that the latter does not apply is that mainline changed:
> "configure: remove version argument from gcc_GAS_CHECK_FEATURE"
> in https://gcc.gnu.org/g:e0b6d0b39c69372e4a66f44d218e0244bb549d83
> which was fixed for GCN a bit later in commit
> "configure: Adjust several assembler checks to remove an unused parm."
> https://gcc.gnu.org/g:e5d9873fcb6f90d03b7534af53de39ec65d0cdc5
> 
> The only change is "," to ",," in configure.ac; 'configure' itself
> was already fine.
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