[llvm] [AMDGPU] Use removeFnAttrFromReachable in lower-module-lds pass. (PR #92686)

[via llvm-commits]

llvmbot wrote:


<!--LLVM PR SUMMARY COMMENT-->

@llvm/pr-subscribers-backend-amdgpu

Author: Chaitanya (skc7)

<details>
<summary>Changes</summary>



---
Full diff: https://github.com/llvm/llvm-project/pull/92686.diff


1 Files Affected:

- (modified) llvm/lib/Target/AMDGPU/AMDGPULowerModuleLDSPass.cpp (+1-43) 


``````````diff
diff --git a/llvm/lib/Target/AMDGPU/AMDGPULowerModuleLDSPass.cpp b/llvm/lib/Target/AMDGPU/AMDGPULowerModuleLDSPass.cpp
index 2c7163a775372..625ac0230f160 100644
--- a/llvm/lib/Target/AMDGPU/AMDGPULowerModuleLDSPass.cpp
+++ b/llvm/lib/Target/AMDGPU/AMDGPULowerModuleLDSPass.cpp
@@ -862,48 +862,6 @@ class AMDGPULowerModuleLDS {
     return N;
   }
 
-  /// Strip "amdgpu-no-lds-kernel-id" from any functions where we may have
-  /// introduced its use. If AMDGPUAttributor ran prior to the pass, we inferred
-  /// the lack of llvm.amdgcn.lds.kernel.id calls.
-  void removeNoLdsKernelIdFromReachable(CallGraph &CG, Function *KernelRoot) {
-    KernelRoot->removeFnAttr("amdgpu-no-lds-kernel-id");
-
-    SmallVector<Function *> WorkList({CG[KernelRoot]->getFunction()});
-    SmallPtrSet<Function *, 8> Visited;
-    bool SeenUnknownCall = false;
-
-    while (!WorkList.empty()) {
-      Function *F = WorkList.pop_back_val();
-
-      for (auto &CallRecord : *CG[F]) {
-        if (!CallRecord.second)
-          continue;
-
-        Function *Callee = CallRecord.second->getFunction();
-        if (!Callee) {
-          if (!SeenUnknownCall) {
-            SeenUnknownCall = true;
-
-            // If we see any indirect calls, assume nothing about potential
-            // targets.
-            // TODO: This could be refined to possible LDS global users.
-            for (auto &ExternalCallRecord : *CG.getExternalCallingNode()) {
-              Function *PotentialCallee =
-                  ExternalCallRecord.second->getFunction();
-              assert(PotentialCallee);
-              if (!isKernelLDS(PotentialCallee))
-                PotentialCallee->removeFnAttr("amdgpu-no-lds-kernel-id");
-            }
-          }
-        } else {
-          Callee->removeFnAttr("amdgpu-no-lds-kernel-id");
-          if (Visited.insert(Callee).second)
-            WorkList.push_back(Callee);
-        }
-      }
-    }
-  }
-
   DenseMap<Function *, GlobalVariable *> lowerDynamicLDSVariables(
       Module &M, LDSUsesInfoTy &LDSUsesInfo,
       DenseSet<Function *> const &KernelsThatIndirectlyAllocateDynamicLDS,
@@ -1059,7 +1017,7 @@ class AMDGPULowerModuleLDS {
       //
       // TODO: We could filter out subgraphs that do not access LDS globals.
       for (Function *F : KernelsThatAllocateTableLDS)
-        removeNoLdsKernelIdFromReachable(CG, F);
+        removeFnAttrFromReachable(CG, F, "amdgpu-no-lds-kernel-id");
     }
 
     DenseMap<Function *, GlobalVariable *> KernelToCreatedDynamicLDS =

``````````

</details>


https://github.com/llvm/llvm-project/pull/92686