}
+/// This function returns the identity element (or neutral element) for
+/// the operation K.
static unsigned
getReductionIdentity(LoopVectorizationLegality::ReductionKind K) {
switch (K) {
case LoopVectorizationLegality::IntegerXor:
case LoopVectorizationLegality::IntegerAdd:
case LoopVectorizationLegality::IntegerOr:
+ // Adding, Xoring, Oring zero to a number does not change it.
return 0;
case LoopVectorizationLegality::IntegerMult:
+ // Multiplying a number by 1 does not change it.
return 1;
case LoopVectorizationLegality::IntegerAnd:
+ // AND-ing a number with an all-1 value does not change it.
return -1;
default:
llvm_unreachable("Unknown reduction kind");