// Compute a range A-B and add it to the list.
void HexagonBlockRanges::RangeList::addsub(const IndexRange &A,
const IndexRange &B) {
// Exclusion of non-overlapping ranges makes some checks simpler
// later in this function.
if (!A.overlaps(B)) {
// A - B = A.
add(A);
return;
}
IndexType AS = A.start(), AE = A.end();
IndexType BS = B.start(), BE = B.end();
// If AE is None, then A is included in B, since A and B overlap.
// The result of subtraction if empty, so just return.
if (AE == IndexType::None)
return;
if (AS < BS) {
// A starts before B.
// AE cannot be None since A and B overlap.
assert(AE != IndexType::None);
// Add the part of A that extends on the "less" side of B.
add(AS, BS, A.Fixed, false);
}
if (BE < AE) {
// BE cannot be Exit here.
if (BE == IndexType::None)
add(BS, AE, A.Fixed, false);
else
add(BE, AE, A.Fixed, false);
}
}
