[all-commits] [llvm/llvm-project] d5fe1b: [AIX][TLS] Disallow the use of -maix-small-local-e...

[Amy Kwan via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: d5fe1bd081ec129a1259cccf5171692d87dbd1f3
      https://github.com/llvm/llvm-project/commit/d5fe1bd081ec129a1259cccf5171692d87dbd1f3
  Author: Amy Kwan <amy.kwan1 at ibm.com>
  Date:   2024-01-26 (Fri, 26 Jan 2024)

  Changed paths:
    M clang/lib/Basic/Targets/PPC.cpp
    M clang/lib/Driver/ToolChains/Arch/PPC.cpp
    M clang/test/Driver/aix-small-local-exec-tls.c
    M llvm/lib/Target/PowerPC/PPCSubtarget.cpp
    M llvm/test/CodeGen/PowerPC/check-aix-small-local-exec-tls-opt-IRattribute.ll

  Log Message:
  -----------
  [AIX][TLS] Disallow the use of -maix-small-local-exec-tls and -fno-data-sections (#79252)

This patch disallows the use of the -maix-small-local-exec-tls and
-fno-data-sections options within clang, and also disallows the use of
the aix-small-local-exec-tls attribute with the -data-sections=false
option in llc.

This is because having data sections off when using the
aix-small-local-exec-tls feature is not ideal for performance. As the
small-local-exec-tls region is a limited resource, this space should not
used for variables that may be replaced.

Note, that on AIX, data sections is turned on by default, so this patch
makes it so that a diagnostic is emitted when users explicitly turn off
data sections while using the aix-small-local-exec-tls feature.