[SPIRV] Fix assertion violation caused by unexpected ConstantExpr. #170524
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mgcarrasco
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@llvm/pr-subscribers-backend-spir-v Author: Manuel Carrasco (mgcarrasco) Changes
This LLVM defect was identified via the AMD Fuzzing project. Full diff: https://github.com/llvm/llvm-project/pull/170524.diff 2 Files Affected:
diff --git a/llvm/lib/Target/SPIRV/SPIRVEmitIntrinsics.cpp b/llvm/lib/Target/SPIRV/SPIRVEmitIntrinsics.cpp
index eea49bfdaf04b..736020406ce96 100644
--- a/llvm/lib/Target/SPIRV/SPIRVEmitIntrinsics.cpp
+++ b/llvm/lib/Target/SPIRV/SPIRVEmitIntrinsics.cpp
@@ -2816,13 +2816,10 @@ SPIRVEmitIntrinsics::simplifyZeroLengthArrayGepInst(GetElementPtrInst *GEP) {
ArrayType *ArrTy = dyn_cast<ArrayType>(SrcTy);
if (ArrTy && ArrTy->getNumElements() == 0 &&
PatternMatch::match(Indices[0], PatternMatch::m_Zero())) {
- IRBuilder<> Builder(GEP);
Indices.erase(Indices.begin());
SrcTy = ArrTy->getElementType();
- Value *NewGEP = Builder.CreateGEP(SrcTy, GEP->getPointerOperand(), Indices,
- "", GEP->getNoWrapFlags());
- assert(llvm::isa<GetElementPtrInst>(NewGEP) && "NewGEP should be a GEP");
- return cast<GetElementPtrInst>(NewGEP);
+ return GetElementPtrInst::Create(SrcTy, GEP->getPointerOperand(), Indices,
+ GEP->getNoWrapFlags(), "", GEP);
}
return nullptr;
}
diff --git a/llvm/test/CodeGen/SPIRV/const-array-gep.ll b/llvm/test/CodeGen/SPIRV/const-array-gep.ll
new file mode 100644
index 0000000000000..c1dfe18aee6e6
--- /dev/null
+++ b/llvm/test/CodeGen/SPIRV/const-array-gep.ll
@@ -0,0 +1,19 @@
+; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py UTC_ARGS: --version 6
+; RUN: llc -O0 -mtriple=spirv64-unknown-unknown < %s | FileCheck %s
+; RUN: %if spirv-tools %{ llc -O0 -mtriple=spirv64-unknown-unknown < %s -filetype=obj | spirv-val %}
+
+define spir_kernel void @_Z6kernelPi() addrspace(4) {
+; CHECK-LABEL: _Z6kernelPi
+; CHECK: %12 = OpFunction %3 None %4 ; -- Begin function _Z6kernelPi
+; CHECK-NEXT: %2 = OpLabel
+; CHECK-NEXT: %13 = OpBitcast %6 %11
+; CHECK-NEXT: %14 = OpInBoundsPtrAccessChain %6 %13 %10
+; CHECK-NEXT: %15 = OpConvertPtrToU %5 %14
+; CHECK-NEXT: %16 = OpBitcast %6 %11
+; CHECK-NEXT: OpStore %16 %15 Aligned 4
+; CHECK-NEXT: OpReturn
+; CHECK-NEXT: OpFunctionEnd
+entry:
+ store i32 ptrtoint (ptr addrspace(4) getelementptr inbounds ([0 x i32], ptr addrspace(4) null, i64 0, i64 1) to i32), ptr addrspace(4) null, align 4
+ ret void
+}
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mgcarrasco
requested review from
MrSidims,
VyacheslavLevytskyy and
michalpaszkowski
maarquitos14
approved these changes
Dec 8, 2025
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LLVM Buildbot has detected a new failure on builder Full details are available at: https://lab.llvm.org/buildbot/#/builders/162/builds/36659 Here is the relevant piece of the build log for the reference |
Collaborator
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LLVM Buildbot has detected a new failure on builder Full details are available at: https://lab.llvm.org/buildbot/#/builders/211/builds/4393 Here is the relevant piece of the build log for the reference |
Collaborator
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LLVM Buildbot has detected a new failure on builder Full details are available at: https://lab.llvm.org/buildbot/#/builders/174/builds/28559 Here is the relevant piece of the build log for the reference |
Collaborator
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LLVM Buildbot has detected a new failure on builder Full details are available at: https://lab.llvm.org/buildbot/#/builders/129/builds/34551 Here is the relevant piece of the build log for the reference |
honeygoyal
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Dec 9, 2025
…lvm#170524) `SPIRVEmitIntrinsics::simplifyZeroLengthArrayGepInst` asserted that it always expected a `GetElementPtrInst` from `IRBuilder::CreateGEP` (which returns a `Value`). `IRBuilder` can fold and return a `ConstantExpr` instead, thus violating the assertion. The patch fixes this by using `GetElementPtrInst::Create` to always return a `GetElementPtrInst`. This LLVM defect was identified via the AMD Fuzzing project.
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SPIRVEmitIntrinsics::simplifyZeroLengthArrayGepInstasserted that it always expected aGetElementPtrInstfromIRBuilder::CreateGEP(which returns aValue).IRBuildercan fold and return aConstantExprinstead, thus violating the assertion. The patch fixes this by usingGetElementPtrInst::Createto always return aGetElementPtrInst.This LLVM defect was identified via the AMD Fuzzing project.