diff --git a/llvm/lib/Transforms/Scalar/LowerMatrixIntrinsics.cpp b/llvm/lib/Transforms/Scalar/LowerMatrixIntrinsics.cpp
--- a/llvm/lib/Transforms/Scalar/LowerMatrixIntrinsics.cpp
+++ b/llvm/lib/Transforms/Scalar/LowerMatrixIntrinsics.cpp
@@ -246,7 +246,7 @@
 
     void setVector(unsigned i, Value *V) { Vectors[i] = V; }
 
-    Type *getElementType() { return getVectorTy()->getElementType(); }
+    Type *getElementType() const { return getVectorTy()->getElementType(); }
 
     unsigned getNumVectors() const {
       if (isColumnMajor())
@@ -276,7 +276,7 @@
       return getVectorTy();
     }
 
-    VectorType *getVectorTy() {
+    VectorType *getVectorTy() const {
       return cast<VectorType>(Vectors[0]->getType());
     }
 
@@ -1370,6 +1370,8 @@
 
     const MatrixTy &Lhs = getMatrix(MatMul->getArgOperand(0), LShape, Builder);
     const MatrixTy &Rhs = getMatrix(MatMul->getArgOperand(1), RShape, Builder);
+    assert(Lhs.getElementType() == Rhs.getElementType() &&
+           "Matrix multiply argument element types do not match.");
 
     const unsigned R = LShape.NumRows;
     const unsigned C = RShape.NumColumns;
@@ -1377,6 +1379,8 @@
 
     // Initialize the output
     MatrixTy Result(R, C, EltType);
+    assert(Lhs.getElementType() == Result.getElementType() &&
+           "Matrix multiply result element type does not match arguments.");
 
     bool AllowContract = AllowContractEnabled || (isa<FPMathOperator>(MatMul) &&
                                                   MatMul->hasAllowContract());