+/// Get the intersection (logical and) of all of the potential IR flags
+/// of each scalar operation (VL) that will be converted into a vector (I).
+/// Flag set: NSW, NUW, exact, and all of fast-math.
+static void propagateIRFlags(Value *I, ArrayRef<Value *> VL) {
+ if (auto *VecOp = dyn_cast<BinaryOperator>(I)) {
+ if (auto *Intersection = dyn_cast<BinaryOperator>(VL[0])) {
+ // Intersection is initialized to the 0th scalar,
+ // so start counting from index '1'.
+ for (int i = 1, e = VL.size(); i < e; ++i) {
+ if (auto *Scalar = dyn_cast<BinaryOperator>(VL[i]))
+ Intersection->andIRFlags(Scalar);
+ }
+ VecOp->copyIRFlags(Intersection);
+ }
+ }
+}
+