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[DirectX] Support ConstExpr GEPs
- Fixes #150050 - Address the issue of many nested geps - Check for ConstantExpr GEP if we see it check if it needs a global replacement with a new type. Create the new constExpr Gep and set the pointer operand to it. Finally cleanup and remove the old nested geps.
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‎llvm/lib/Target/DirectX/DXILDataScalarization.cpp

Lines changed: 73 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -300,11 +300,84 @@ bool DataScalarizerVisitor::visitExtractElementInst(ExtractElementInst &EEI) {
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return replaceDynamicExtractElementInst(EEI);
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}
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static void buildConstExprGEPChain(GetElementPtrInst &GEPI, Value *CurrentPtr,
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SmallVector<ConstantExpr *, 4> &GEPChain,
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IRBuilder<> &Builder) {
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// Process the rest of the chain in reverse order (skipping the innermost)
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for (int I = GEPChain.size() - 2; I >= 0; I--) {
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ConstantExpr *CE = GEPChain[I];
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GetElementPtrInst *GEPInst =
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cast<GetElementPtrInst>(CE->getAsInstruction());
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GEPInst->insertBefore(GEPI.getIterator());
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SmallVector<Value *, MaxVecSize> CurrIndices(GEPInst->indices());
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// Create a new GEP instruction
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Type *SourceTy = GEPInst->getSourceElementType();
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CurrentPtr =
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Builder.CreateGEP(SourceTy, CurrentPtr, CurrIndices, GEPInst->getName(),
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GEPInst->getNoWrapFlags());
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// If this is the outermost GEP, update the main GEPI
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if (I == 0) {
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GEPI.setOperand(GEPI.getPointerOperandIndex(), CurrentPtr);
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}
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// Clean up the temporary instruction
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GEPInst->eraseFromParent();
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}
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}
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bool DataScalarizerVisitor::visitGetElementPtrInst(GetElementPtrInst &GEPI) {
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Value *PtrOperand = GEPI.getPointerOperand();
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Type *OrigGEPType = GEPI.getSourceElementType();
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Type *NewGEPType = OrigGEPType;
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bool NeedsTransform = false;
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// Check if the pointer operand is a ConstantExpr GEP
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if (auto *PtrOpGEPCE = dyn_cast<ConstantExpr>(PtrOperand);
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PtrOpGEPCE && PtrOpGEPCE->getOpcode() == Instruction::GetElementPtr) {
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// Collect all nested GEPs in the chain
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SmallVector<ConstantExpr *, 4> GEPChain;
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Value *BasePointer = PtrOpGEPCE->getOperand(0);
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GEPChain.push_back(PtrOpGEPCE);
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// Walk up the chain to find all nested GEPs and the base pointer
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while (auto *NextGEP = dyn_cast<ConstantExpr>(BasePointer)) {
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if (NextGEP->getOpcode() != Instruction::GetElementPtr)
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break;
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GEPChain.push_back(NextGEP);
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BasePointer = NextGEP->getOperand(0);
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}
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// Check if the base pointer is a global that needs replacement
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if (GlobalVariable *NewGlobal = lookupReplacementGlobal(BasePointer)) {
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IRBuilder<> Builder(&GEPI);
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// Create a new GEP for the innermost GEP (last in the chain)
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ConstantExpr *InnerGEPCE = GEPChain.back();
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GetElementPtrInst *InnerGEP =
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cast<GetElementPtrInst>(InnerGEPCE->getAsInstruction());
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InnerGEP->insertBefore(GEPI.getIterator());
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SmallVector<Value *, MaxVecSize> Indices(InnerGEP->indices());
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Type *NewGEPType = NewGlobal->getValueType();
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Value *NewInnerGEP =
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Builder.CreateGEP(NewGEPType, NewGlobal, Indices, InnerGEP->getName(),
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InnerGEP->getNoWrapFlags());
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// If there's only one GEP in the chain, update the main GEPI directly
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if (GEPChain.size() == 1)
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GEPI.setOperand(GEPI.getPointerOperandIndex(), NewInnerGEP);
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else
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// For multiple GEPs, we need to create a chain of GEPs
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buildConstExprGEPChain(GEPI, NewInnerGEP, GEPChain, Builder);
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// Clean up the innermost GEP
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InnerGEP->eraseFromParent();
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return true;
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}
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}
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if (GlobalVariable *NewGlobal = lookupReplacementGlobal(PtrOperand)) {
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NewGEPType = NewGlobal->getValueType();

‎llvm/test/CodeGen/DirectX/bugfix_150050_data_scalarize_const_gep.ll

Lines changed: 80 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -0,0 +1,80 @@
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; RUN: opt -S -passes='dxil-data-scalarization' -mtriple=dxil-pc-shadermodel6.4-library %s | FileCheck %s --check-prefixes=SCHECK,CHECK
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; RUN: opt -S -passes='dxil-data-scalarization,function(scalarizer<load-store>),dxil-flatten-arrays' -mtriple=dxil-pc-shadermodel6.4-library %s | FileCheck %s --check-prefixes=FCHECK,CHECK
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@aTile = hidden addrspace(3) global [10 x [10 x <4 x i32>]] zeroinitializer, align 16
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@bTile = hidden addrspace(3) global [10 x [10 x i32]] zeroinitializer, align 16
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@cTile = internal global [2 x [2 x <2 x i32>]] zeroinitializer, align 16
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@dTile = internal global [2 x [2 x [2 x <2 x i32>]]] zeroinitializer, align 16
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define void @CSMain() {
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; CHECK-LABEL: define void @CSMain() {
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; CHECK-NEXT: [[ENTRY:.*:]]
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; CHECK-NEXT: [[AFRAGPACKED_I_SCALARIZE:%.*]] = alloca [4 x i32], align 16
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;
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; SCHECK-NEXT: [[TMP0:%.*]] = getelementptr inbounds [10 x <4 x i32>], ptr addrspace(3) getelementptr inbounds ([10 x [10 x [4 x i32]]], ptr addrspace(3) @aTile.scalarized, i32 0, i32 1), i32 0, i32 2
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; SCHECK-NEXT: [[TMP1:%.*]] = load <4 x i32>, ptr addrspace(3) [[TMP0]], align 16
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; SCHECK-NEXT: store <4 x i32> [[TMP1]], ptr [[AFRAGPACKED_I_SCALARIZE]], align 16
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;
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; FCHECK-NEXT: [[AFRAGPACKED_I_SCALARIZE_I14:%.*]] = getelementptr [4 x i32], ptr [[AFRAGPACKED_I_SCALARIZE]], i32 0, i32 1
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; FCHECK-NEXT: [[AFRAGPACKED_I_SCALARIZE_I25:%.*]] = getelementptr [4 x i32], ptr [[AFRAGPACKED_I_SCALARIZE]], i32 0, i32 2
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; FCHECK-NEXT: [[AFRAGPACKED_I_SCALARIZE_I36:%.*]] = getelementptr [4 x i32], ptr [[AFRAGPACKED_I_SCALARIZE]], i32 0, i32 3
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; FCHECK-NEXT: [[DOTI07:%.*]] = load i32, ptr addrspace(3) getelementptr inbounds ([400 x i32], ptr addrspace(3) @aTile.scalarized.1dim, i32 0, i32 48), align 16
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; FCHECK-NEXT: [[DOTI119:%.*]] = load i32, ptr addrspace(3) getelementptr ([400 x i32], ptr addrspace(3) @aTile.scalarized.1dim, i32 0, i32 49), align 4
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; FCHECK-NEXT: [[DOTI2211:%.*]] = load i32, ptr addrspace(3) getelementptr ([400 x i32], ptr addrspace(3) @aTile.scalarized.1dim, i32 0, i32 50), align 8
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; FCHECK-NEXT: [[DOTI3313:%.*]] = load i32, ptr addrspace(3) getelementptr ([400 x i32], ptr addrspace(3) @aTile.scalarized.1dim, i32 0, i32 51), align 4
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; FCHECK-NEXT: store i32 [[DOTI07]], ptr [[AFRAGPACKED_I_SCALARIZE]], align 16
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; FCHECK-NEXT: store i32 [[DOTI119]], ptr [[AFRAGPACKED_I_SCALARIZE_I14]], align 4
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; FCHECK-NEXT: store i32 [[DOTI2211]], ptr [[AFRAGPACKED_I_SCALARIZE_I25]], align 8
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; FCHECK-NEXT: store i32 [[DOTI3313]], ptr [[AFRAGPACKED_I_SCALARIZE_I36]], align 4
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;
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; CHECK-NEXT: ret void
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entry:
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%aFragPacked.i = alloca <4 x i32>, align 16
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%0 = load <4 x i32>, ptr addrspace(3) getelementptr inbounds ([10 x <4 x i32>], ptr addrspace(3) getelementptr inbounds ([10 x [10 x <4 x i32>]], ptr addrspace(3) @aTile, i32 0, i32 1), i32 0, i32 2), align 16
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store <4 x i32> %0, ptr %aFragPacked.i, align 16
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ret void
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}
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define void @Main() {
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; CHECK-LABEL: define void @Main() {
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; CHECK-NEXT: [[ENTRY:.*:]]
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; CHECK-NEXT: [[BFRAGPACKED_I:%.*]] = alloca i32, align 16
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;
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; SCHECK-NEXT: [[TMP0:%.*]] = getelementptr inbounds [10 x i32], ptr addrspace(3) getelementptr inbounds ([10 x [10 x i32]], ptr addrspace(3) @bTile, i32 0, i32 1), i32 0, i32 1
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; SCHECK-NEXT: [[TMP1:%.*]] = load i32, ptr addrspace(3) [[TMP0]], align 16
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; SCHECK-NEXT: store i32 [[TMP1]], ptr [[BFRAGPACKED_I]], align 16
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;
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; FCHECK-NEXT: [[TMP0:%.*]] = load i32, ptr addrspace(3) getelementptr inbounds ([100 x i32], ptr addrspace(3) @bTile.1dim, i32 0, i32 11), align 16
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; FCHECK-NEXT: store i32 [[TMP0]], ptr [[BFRAGPACKED_I]], align 16
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;
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; CHECK-NEXT: ret void
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entry:
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%bFragPacked.i = alloca i32, align 16
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%0 = load i32, ptr addrspace(3) getelementptr inbounds ([10 x i32], ptr addrspace(3) getelementptr inbounds ([10 x [10 x i32]], ptr addrspace(3) @bTile, i32 0, i32 1), i32 0, i32 1), align 16
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store i32 %0, ptr %bFragPacked.i, align 16
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ret void
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}
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define void @global_nested_geps_3d() {
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; CHECK-LABEL: define void @global_nested_geps_3d() {
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; SCHECK-NEXT: [[TMP1:%.*]] = getelementptr inbounds <2 x i32>, ptr getelementptr inbounds ([2 x <2 x i32>], ptr getelementptr inbounds ([2 x [2 x [2 x i32]]], ptr @cTile.scalarized, i32 0, i32 1), i32 0, i32 1), i32 0, i32 1
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; SCHECK-NEXT: [[TMP2:%.*]] = load i32, ptr [[TMP1]], align 4
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;
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; FCHECK-NEXT: [[TMP1:%.*]] = load i32, ptr getelementptr inbounds ([8 x i32], ptr @cTile.scalarized.1dim, i32 0, i32 7), align 4
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;
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; CHECK-NEXT: ret void
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%1 = load i32, i32* getelementptr inbounds (<2 x i32>, <2 x i32>* getelementptr inbounds ([2 x <2 x i32>], [2 x <2 x i32>]* getelementptr inbounds ([2 x [2 x <2 x i32>]], [2 x [2 x <2 x i32>]]* @cTile, i32 0, i32 1), i32 0, i32 1), i32 0, i32 1), align 4
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ret void
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}
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define void @global_nested_geps_4d() {
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; CHECK-LABEL: define void @global_nested_geps_4d() {
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; SCHECK-NEXT: [[TMP1:%.*]] = getelementptr inbounds <2 x i32>, ptr getelementptr inbounds ([2 x <2 x i32>], ptr getelementptr inbounds ([2 x [2 x <2 x i32>]], ptr getelementptr inbounds ([2 x [2 x [2 x [2 x i32]]]], ptr @dTile.scalarized, i32 0, i32 1), i32 0, i32 1), i32 0, i32 1), i32 0, i32 1
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; SCHECK-NEXT: [[TMP2:%.*]] = load i32, ptr [[TMP1]], align 4
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;
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; FCHECK-NEXT: [[TMP1:%.*]] = load i32, ptr getelementptr inbounds ([16 x i32], ptr @dTile.scalarized.1dim, i32 0, i32 15), align 4
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;
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; CHECK-NEXT: ret void
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%1 = load i32, i32* getelementptr inbounds (<2 x i32>, <2 x i32>* getelementptr inbounds ([2 x <2 x i32>], [2 x <2 x i32>]* getelementptr inbounds ([2 x [2 x <2 x i32>]], [2 x [2 x <2 x i32>]]* getelementptr inbounds ([2 x [2 x [2 x <2 x i32>]]], [2 x [2 x [2 x <2 x i32>]]]* @dTile, i32 0, i32 1), i32 0, i32 1), i32 0, i32 1), i32 0, i32 1), align 4
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ret void
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}

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