[llvm] a17ffaf - [AMDGPU] Avoid unnecessary zero-index GEPs

[Nikita Popov via llvm-commits]

Author: Nikita Popov
Date: 2026-02-13T15:10:42+01:00
New Revision: a17ffaf9d08a1a88fba522acfb6bd19b5ec90c24

URL: https://github.com/llvm/llvm-project/commit/a17ffaf9d08a1a88fba522acfb6bd19b5ec90c24
DIFF: https://github.com/llvm/llvm-project/commit/a17ffaf9d08a1a88fba522acfb6bd19b5ec90c24.diff

LOG: [AMDGPU] Avoid unnecessary zero-index GEPs

These are no-ops.

Added: 
    

Modified: 
    llvm/lib/Target/AMDGPU/AMDGPULowerModuleLDSPass.cpp
    llvm/lib/Target/AMDGPU/AMDGPUSwLowerLDS.cpp

Removed: 
    


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diff  --git a/llvm/lib/Target/AMDGPU/AMDGPULowerModuleLDSPass.cpp b/llvm/lib/Target/AMDGPU/AMDGPULowerModuleLDSPass.cpp
index 588eee036a4e2..17260a875db72 100644
--- a/llvm/lib/Target/AMDGPU/AMDGPULowerModuleLDSPass.cpp
+++ b/llvm/lib/Target/AMDGPU/AMDGPULowerModuleLDSPass.cpp
@@ -888,10 +888,7 @@ class AMDGPULowerModuleLDS {
 
           markUsedByKernel(func, N);
 
-          auto *emptyCharArray = ArrayType::get(Type::getInt8Ty(Ctx), 0);
-          auto *GEP = ConstantExpr::getGetElementPtr(
-              emptyCharArray, N, ConstantInt::get(I32, 0), true);
-          newDynamicLDS.push_back(ConstantExpr::getPtrToInt(GEP, I32));
+          newDynamicLDS.push_back(ConstantExpr::getPtrToInt(N, I32));
         } else {
           newDynamicLDS.push_back(PoisonValue::get(I32));
         }

diff  --git a/llvm/lib/Target/AMDGPU/AMDGPUSwLowerLDS.cpp b/llvm/lib/Target/AMDGPU/AMDGPUSwLowerLDS.cpp
index 3fd554a4c0443..362c221aa1392 100644
--- a/llvm/lib/Target/AMDGPU/AMDGPUSwLowerLDS.cpp
+++ b/llvm/lib/Target/AMDGPU/AMDGPUSwLowerLDS.cpp
@@ -990,7 +990,6 @@ void AMDGPUSwLowerLDS::buildNonKernelLDSBaseTable(
   auto &Kernels = NKLDSParams.OrderedKernels;
   if (Kernels.empty())
     return;
-  Type *Int32Ty = IRB.getInt32Ty();
   const size_t NumberKernels = Kernels.size();
   ArrayType *AllKernelsOffsetsType =
       ArrayType::get(IRB.getPtrTy(AMDGPUAS::LOCAL_ADDRESS), NumberKernels);
@@ -998,12 +997,7 @@ void AMDGPUSwLowerLDS::buildNonKernelLDSBaseTable(
   for (size_t i = 0; i < NumberKernels; i++) {
     Function *Func = Kernels[i];
     auto &LDSParams = FuncLDSAccessInfo.KernelToLDSParametersMap[Func];
-    GlobalVariable *SwLDS = LDSParams.SwLDS;
-    assert(SwLDS);
-    Constant *GEPIdx[] = {ConstantInt::get(Int32Ty, 0)};
-    Constant *GEP =
-        ConstantExpr::getGetElementPtr(SwLDS->getType(), SwLDS, GEPIdx, true);
-    OverallConstantExprElts[i] = GEP;
+    OverallConstantExprElts[i] = LDSParams.SwLDS;
   }
   Constant *init =
       ConstantArray::get(AllKernelsOffsetsType, OverallConstantExprElts);