[llvm] Revert "[AMDGPU][LTO] Assume closed world after linking (#105845)" (PR #106889)

[via llvm-commits]

llvmbot wrote:


<!--LLVM PR SUMMARY COMMENT-->
@llvm/pr-subscribers-backend-amdgpu

@llvm/pr-subscribers-lto

Author: Shilei Tian (shiltian)

<details>
<summary>Changes</summary>

We can't assume closed world even in full LTO post-link stage. It is only true
if we are building a "GPU executable". However, AMDGPU does support "dyamic
library". I'm not aware of any approach to tell if it is relocatable link when
we create the pass. For now let's revert the patch. We can re-enable it once we
can handle it correctly.

---
Full diff: https://github.com/llvm/llvm-project/pull/106889.diff


3 Files Affected:

- (modified) llvm/lib/Target/AMDGPU/AMDGPUAttributor.cpp (-4) 
- (modified) llvm/lib/Target/AMDGPU/AMDGPUTargetMachine.cpp (+2-6) 
- (removed) llvm/test/LTO/AMDGPU/gpu-rdc-amdgpu-attrs.ll (-13) 


``````````diff
diff --git a/llvm/lib/Target/AMDGPU/AMDGPUAttributor.cpp b/llvm/lib/Target/AMDGPU/AMDGPUAttributor.cpp
index 0d7b4caa8156ed..72049f0aa6b86e 100644
--- a/llvm/lib/Target/AMDGPU/AMDGPUAttributor.cpp
+++ b/llvm/lib/Target/AMDGPU/AMDGPUAttributor.cpp
@@ -1065,10 +1065,6 @@ static bool runImpl(Module &M, AnalysisGetter &AG, TargetMachine &TM,
 
   Attributor A(Functions, InfoCache, AC);
 
-  LLVM_DEBUG(dbgs() << "Module " << M.getName() << " is "
-                    << (AC.IsClosedWorldModule ? "" : "not ")
-                    << "assumed to be a closed world.\n");
-
   for (Function &F : M) {
     if (F.isIntrinsic())
       continue;
diff --git a/llvm/lib/Target/AMDGPU/AMDGPUTargetMachine.cpp b/llvm/lib/Target/AMDGPU/AMDGPUTargetMachine.cpp
index a769bc9e486573..7df39f35478077 100644
--- a/llvm/lib/Target/AMDGPU/AMDGPUTargetMachine.cpp
+++ b/llvm/lib/Target/AMDGPU/AMDGPUTargetMachine.cpp
@@ -771,12 +771,8 @@ void AMDGPUTargetMachine::registerPassBuilderCallbacks(PassBuilder &PB) {
           PM.addPass(AMDGPUSwLowerLDSPass(*this));
         if (EnableLowerModuleLDS)
           PM.addPass(AMDGPULowerModuleLDSPass(*this));
-
-        if (EnableAMDGPUAttributor && Level != OptimizationLevel::O0) {
-          AMDGPUAttributorOptions Opts;
-          Opts.IsClosedWorld = true;
-          PM.addPass(AMDGPUAttributorPass(*this, Opts));
-        }
+        if (EnableAMDGPUAttributor && Level != OptimizationLevel::O0)
+          PM.addPass(AMDGPUAttributorPass(*this));
       });
 
   PB.registerRegClassFilterParsingCallback(
diff --git a/llvm/test/LTO/AMDGPU/gpu-rdc-amdgpu-attrs.ll b/llvm/test/LTO/AMDGPU/gpu-rdc-amdgpu-attrs.ll
deleted file mode 100644
index 8228f21b56b132..00000000000000
--- a/llvm/test/LTO/AMDGPU/gpu-rdc-amdgpu-attrs.ll
+++ /dev/null
@@ -1,13 +0,0 @@
-; RUN: opt -O3 -debug-only=amdgpu-attributor -S -o - %s 2>&1 | FileCheck %s --check-prefix=PRE-LINK
-; RUN: opt -passes="lto<O3>" -debug-only=amdgpu-attributor -S -o - %s 2>&1 | FileCheck %s --check-prefix=POST-LINK
-
-; REQUIRES: amdgpu-registered-target
-; REQUIRES: asserts
-
-target triple = "amdgcn-amd-amdhsa"
-
-; PRE-LINK: Module {{.*}} is not assumed to be a closed world.
-; POST-LINK: Module {{.*}} is assumed to be a closed world.
-define hidden noundef i32 @_Z3foov() {
-  ret i32 1
-}

``````````

</details>


https://github.com/llvm/llvm-project/pull/106889