utils/TableGen/CodeGenRegisters.cpp

1754     CodeGenRegisterClass *RC1 = RC;
1756     if (RC1 == RC2)
1759     // Compute the set intersection of RC1 and RC2.
1760     const CodeGenRegister::Set &Memb1 = RC1->getMembers();
1772     // If RC1 and RC2 have different spill sizes or alignments, use the
1773     // larger size for sub-classing.  If they are equal, prefer RC1.
1774     if (RC2->SpillSize > RC1->SpillSize ||
1775         (RC2->SpillSize == RC1->SpillSize &&
1776          RC2->SpillAlignment > RC1->SpillAlignment))
1777       std::swap(RC1, RC2);
1779     getOrCreateSubClass(RC1, &Intersection,
1780                         RC1->getName() + "_and_" + RC2->getName());