commit 52843300bf1a3a1cda8a483d520ba750216ff907
author Yaxun (Sam) Liu <yaxun.liu@amd.com> Wed Mar 17 14:31:06 2021 +0000
committer Copybara-Service <copybara-worker@google.com> Sat Apr 17 21:32:40 2021 -0700
tree c2278de56dbf252ad8161801cdceeae3f02086bb
parent d63db98553116f136d61e4b3eb21ccd4aec42f6b

[AMDGPU] Add GlobalDCE before internalization pass

The internalization pass only internalizes global variables
with no users. If the global variable has some dead user,
the internalization pass will not internalize it.

To be able to internalize global variables with dead
users, a global dce pass is needed before the
internalization pass.

This patch adds that.

Reviewed by: Artem Belevich, Matt Arsenault

Differential Revision: https://reviews.llvm.org/D98783

GitOrigin-RevId: 3597f02fd5c62f7c49c71b92e467128ffe2cf9cd

lib/Target/AMDGPU/AMDGPUTargetMachine.cpp

diff --git a/lib/Target/AMDGPU/AMDGPUTargetMachine.cpp b/lib/Target/AMDGPU/AMDGPUTargetMachine.cpp
index ce39609..1b3b56f 100644
--- a/lib/Target/AMDGPU/AMDGPUTargetMachine.cpp
+++ b/lib/Target/AMDGPU/AMDGPUTargetMachine.cpp
@@ -575,6 +575,9 @@
         PM.addPass(AMDGPUPrintfRuntimeBindingPass());
 
         if (InternalizeSymbols) {
+          // Global variables may have dead uses which need to be removed.
+          // Otherwise these useless global variables will not get internalized.
+          PM.addPass(GlobalDCEPass());
           PM.addPass(InternalizePass(mustPreserveGV));
         }
         PM.addPass(AMDGPUPropagateAttributesLatePass(*this));