// Register classes are ordered topologically, so the largest common
// sub-class it the common sub-class with the smallest ID.
- const unsigned *SubA = A->getSubClassMask();
- const unsigned *SubB = B->getSubClassMask();
-
- // We could start the search from max(A.ID, B.ID), but we are only going to
- // execute 2-3 iterations anyway.
- for (unsigned Base = 0, BaseE = getNumRegClasses(); Base < BaseE; Base += 32)
- if (unsigned Common = *SubA++ & *SubB++)
- return getRegClass(Base + CountTrailingZeros_32(Common));
-
- // No common sub-class exists.
- return NULL;
+ return firstCommonClass(A->getSubClassMask(), B->getSubClassMask(), this);
}
const TargetRegisterClass *
// Find Idx in the list of super-register indices.
const uint32_t *Mask = 0;
for (SuperRegClassIterator RCI(B, this); RCI.isValid(); ++RCI)
- if (RCI.getSubReg() == Idx) {
- Mask = RCI.getMask();
- break;
- }
- if (!Mask)
- return 0;
-
- // The bit mask contains all register classes that are projected into B by
- // Idx. Find a class that is also a sub-class of A.
- const uint32_t *SC = A->getSubClassMask();
-
- // Find the first common register class in TV and SC.
- for (unsigned Base = 0, BaseE = getNumRegClasses(); Base < BaseE; Base += 32)
- if (unsigned Common = *Mask++ & *SC++)
- return getRegClass(Base + CountTrailingZeros_32(Common));
+ if (RCI.getSubReg() == Idx)
+ // The bit mask contains all register classes that are projected into B
+ // by Idx. Find a class that is also a sub-class of A.
+ return firstCommonClass(RCI.getMask(), A->getSubClassMask(), this);
return 0;
}