Unverified Commit 75d6f508 authored by Dudeldu's avatar Dudeldu Committed by GitHub
Browse files

[Interpreter] Add initialization of array members (#66172) 

Currently, the interpreter does not initialize `undef` constants of
aggregate types correctly (with respect to arrays).
The initialization of the array elements is skipped although it is valid
to directly write to them. Instructions like
`insertvalue {i32, [4 x i32]} undef, i32 1, 1, 2` therefore lead to a
crash.
This is fixed by initializing array values just as fixed-size vectors or
structs.
parent 97e06a0d

llvm/lib/ExecutionEngine/ExecutionEngine.cpp

+13 −1
Original line number Diff line number Diff line
@@ -618,7 +618,18 @@ GenericValue ExecutionEngine::getConstantValue(const Constant *C) { 
      case Type::ScalableVectorTyID:

        report_fatal_error(

            "Scalable vector support not yet implemented in ExecutionEngine");

      case Type::FixedVectorTyID:

      case Type::ArrayTyID: {

        auto *ArrTy = cast<ArrayType>(C->getType());

        Type *ElemTy = ArrTy->getElementType();

        unsigned int elemNum = ArrTy->getNumElements();

        Result.AggregateVal.resize(elemNum);

        if (ElemTy->isIntegerTy())

          for (unsigned int i = 0; i < elemNum; ++i)

            Result.AggregateVal[i].IntVal =

                APInt(ElemTy->getPrimitiveSizeInBits(), 0);

        break;

      }

      case Type::FixedVectorTyID: {

        // if the whole vector is 'undef' just reserve memory for the value.

        auto *VTy = cast<FixedVectorType>(C->getType());

        Type *ElemTy = VTy->getElementType();
@@ -630,6 +641,7 @@ GenericValue ExecutionEngine::getConstantValue(const Constant *C) { 
                APInt(ElemTy->getPrimitiveSizeInBits(), 0);

        break;

      }

    }

    return Result;

  }

llvm/test/ExecutionEngine/2010-01-15-UndefValue.ll

+1 −0
Original line number Diff line number Diff line
@@ -4,5 +4,6 @@ define i32 @main() { 
       %a = add i32 0, undef

       %b = fadd float 0.0, undef

       %c = fadd double 0.0, undef

       %d = insertvalue {i32, [4 x i32]} undef, i32 1, 1, 2

       ret i32 0

}