[clang] [llvm] [AMDGPU] Introduce GFX9/10.1/10.3/11 Generic Targets (PR #76955)

[Tony Tye via cfe-commits]

================
@@ -1642,80 +1746,118 @@ The AMDGPU backend uses the following ELF header:
      ``EF_AMDGPU_FEATURE_SRAMECC_ON_V4``          0xc00 SRAMECC enabled.
      ============================================ ===== ===================================
 
+  .. table:: AMDGPU ELF Header ``e_flags`` for Code Object V6 and After
+     :name: amdgpu-elf-header-e_flags-table-v6-onwards
+
+     ============================================ ========== =========================================
+     Name                                         Value      Description
+     ============================================ ========== =========================================
+     ``EF_AMDGPU_MACH``                           0x0ff      AMDGPU processor selection
+                                                             mask for
+                                                             ``EF_AMDGPU_MACH_xxx`` values
+                                                             defined in
+                                                             :ref:`amdgpu-ef-amdgpu-mach-table`.
+     ``EF_AMDGPU_FEATURE_XNACK_V4``               0x300      XNACK selection mask for
+                                                             ``EF_AMDGPU_FEATURE_XNACK_*_V4``
+                                                             values.
+     ``EF_AMDGPU_FEATURE_XNACK_UNSUPPORTED_V4``   0x000      XNACK unsupported.
+     ``EF_AMDGPU_FEATURE_XNACK_ANY_V4``           0x100      XNACK can have any value.
+     ``EF_AMDGPU_FEATURE_XNACK_OFF_V4``           0x200      XNACK disabled.
+     ``EF_AMDGPU_FEATURE_XNACK_ON_V4``            0x300      XNACK enabled.
+     ``EF_AMDGPU_FEATURE_SRAMECC_V4``             0xc00      SRAMECC selection mask for
+                                                             ``EF_AMDGPU_FEATURE_SRAMECC_*_V4``
+                                                             values.
+     ``EF_AMDGPU_FEATURE_SRAMECC_UNSUPPORTED_V4`` 0x000      SRAMECC unsupported.
+     ``EF_AMDGPU_FEATURE_SRAMECC_ANY_V4``         0x400      SRAMECC can have any value.
+     ``EF_AMDGPU_FEATURE_SRAMECC_OFF_V4``         0x800      SRAMECC disabled,
+     ``EF_AMDGPU_FEATURE_SRAMECC_ON_V4``          0xc00      SRAMECC enabled.
+     ``EF_AMDGPU_GENERIC_VERSION_V<X>``           0x01000000 Value between 1 and 255 for generic code
----------------
t-tye wrote:

There needs to be a selection mask like for other fields.

https://github.com/llvm/llvm-project/pull/76955