[llvm] [clang] [AIX][TOC] Add -mtocdata/-mno-tocdata options on AIX (PR #67999)

[Zaara Syeda via llvm-commits]

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@@ -4016,7 +4016,63 @@ Clang expects the GCC executable "gcc.exe" compiled for
 
 AIX
 ^^^
+TOC Data Transformation
+"""""""""""""""""""""""
+TOC data transformation is off by default (``-mno-tocdata``).
+When ``-mtocdata`` is specified, the TOC data transformation will be applied to
+all suitable variables with static storage duration, including static data
+members of classes and block-scope static variables (if not marked as exceptions,
+see further below).
 
+Suitable variables must:
+
+-  have complete types
+-  be independently generated (i.e., not placed in a pool)
+-  be at most as large as a pointer
+-  not be aligned more strictly than a pointer
+-  not be structs containing flexible array members
+-  not have internal linkage
----------------
syzaara wrote:

We found a linker bug on AIX when toc-data was applied to internal linkage variables and can remove this condition once the linker bug is resolved.

https://github.com/llvm/llvm-project/pull/67999