[clang] [Clang][AMDGPU][Driver] Add `avail-extern-gv-in-addrspace-to-local` option when ThinTLO is enabled (PR #144914)

[Shilei Tian via cfe-commits]

https://github.com/shiltian created https://github.com/llvm/llvm-project/pull/144914

On AMDGPU, we need an extra argument `-avail-extern-gv-in-addrspace-to-local=3`
to privatize LDS global variables when ThinLTO is enabled.

>From bf7b936421379ae7e043360c6515136660e2e550 Mon Sep 17 00:00:00 2001
From: Shilei Tian <i at tianshilei.me>
Date: Thu, 19 Jun 2025 11:21:53 -0400
Subject: [PATCH] [Clang][AMDGPU][Driver] Add
 `avail-extern-gv-in-addrspace-to-local` option when ThinTLO is enabled

On AMDGPU, we need an extra argument `-avail-extern-gv-in-addrspace-to-local=3`
to privatize LDS global variables when ThinLTO is enabled.
---
 clang/lib/Driver/ToolChains/Clang.cpp  | 3 +++
 clang/lib/Driver/ToolChains/HIPAMD.cpp | 2 ++
 clang/test/Driver/hip-thinlto.hip      | 1 +
 clang/test/Driver/openmp-offload-gpu.c | 1 +
 4 files changed, 7 insertions(+)

diff --git a/clang/lib/Driver/ToolChains/Clang.cpp b/clang/lib/Driver/ToolChains/Clang.cpp
index a78a1c8978183..3314cdf96a081 100644
--- a/clang/lib/Driver/ToolChains/Clang.cpp
+++ b/clang/lib/Driver/ToolChains/Clang.cpp
@@ -9186,6 +9186,9 @@ void LinkerWrapper::ConstructJob(Compilation &C, const JobAction &JA,
           CmdArgs.push_back(
               Args.MakeArgString("--device-linker=" + TC->getTripleString() +
                                  "=-plugin-opt=-avail-extern-to-local"));
+          CmdArgs.push_back(Args.MakeArgString(
+              "--device-linker=" + TC->getTripleString() +
+              "=-plugin-opt=-avail-extern-gv-in-addrspace-to-local=3"));
           if (Kind == Action::OFK_OpenMP) {
             CmdArgs.push_back(
                 Args.MakeArgString("--device-linker=" + TC->getTripleString() +
diff --git a/clang/lib/Driver/ToolChains/HIPAMD.cpp b/clang/lib/Driver/ToolChains/HIPAMD.cpp
index 74ac8306e7cc1..b8f3a70ee827e 100644
--- a/clang/lib/Driver/ToolChains/HIPAMD.cpp
+++ b/clang/lib/Driver/ToolChains/HIPAMD.cpp
@@ -102,6 +102,8 @@ void AMDGCN::Linker::constructLldCommand(Compilation &C, const JobAction &JA,
   if (IsThinLTO) {
     LldArgs.push_back(Args.MakeArgString("-plugin-opt=-force-import-all"));
     LldArgs.push_back(Args.MakeArgString("-plugin-opt=-avail-extern-to-local"));
+    LldArgs.push_back(Args.MakeArgString(
+        "-plugin-opt=-avail-extern-gv-in-addrspace-to-local=3"));
   }
 
   for (const Arg *A : Args.filtered(options::OPT_mllvm)) {
diff --git a/clang/test/Driver/hip-thinlto.hip b/clang/test/Driver/hip-thinlto.hip
index 4227cd3f2e9f9..bcb7d4e6cb52e 100644
--- a/clang/test/Driver/hip-thinlto.hip
+++ b/clang/test/Driver/hip-thinlto.hip
@@ -3,6 +3,7 @@
 // CHECK: -plugin-opt=thinlto
 // CHECK-SAME: -plugin-opt=-force-import-all
 // CHECK-SAME: -plugin-opt=-avail-extern-to-local
+// CHECK-SAME: -plugin-opt=-avail-extern-gv-in-addrspace-to-local=3
 int main(int, char *[]) {
   return 0;
 }
diff --git a/clang/test/Driver/openmp-offload-gpu.c b/clang/test/Driver/openmp-offload-gpu.c
index f67c2173cb144..2af3e2da3b21c 100644
--- a/clang/test/Driver/openmp-offload-gpu.c
+++ b/clang/test/Driver/openmp-offload-gpu.c
@@ -388,6 +388,7 @@
 // THINLTO-GFX906: --device-compiler=amdgcn-amd-amdhsa=-flto=thin
 // THINLTO-GFX906-SAME: --device-linker=amdgcn-amd-amdhsa=-plugin-opt=-force-import-all
 // THINLTO-GFX906-SAME: --device-linker=amdgcn-amd-amdhsa=-plugin-opt=-avail-extern-to-local
+// THINLTO-GFX906-SAME: --device-linker=amdgcn-amd-amdhsa=-plugin-opt=-avail-extern-gv-in-addrspace-to-local=3
 // THINLTO-GFX906-SAME: --device-linker=amdgcn-amd-amdhsa=-plugin-opt=-amdgpu-internalize-symbols
 //
 // RUN:   %clang -### --target=x86_64-unknown-linux-gnu -fopenmp=libomp \