computeComposites();
}
+//
+// Synthesize missing register class intersections.
+//
+// Make sure that sub-classes of RC exists such that getCommonSubClass(RC, X)
+// returns a maximal register class for all X.
+//
+void CodeGenRegBank::inferCommonSubClass(CodeGenRegisterClass *RC) {
+ for (unsigned rci = 0, rce = RegClasses.size(); rci != rce; ++rci) {
+ CodeGenRegisterClass *RC1 = RC;
+ CodeGenRegisterClass *RC2 = RegClasses[rci];
+ if (RC1 == RC2)
+ continue;
+
+ // Compute the set intersection of RC1 and RC2.
+ const CodeGenRegister::Set &Memb1 = RC1->getMembers();
+ const CodeGenRegister::Set &Memb2 = RC2->getMembers();
+ CodeGenRegister::Set Intersection;
+ std::set_intersection(Memb1.begin(), Memb1.end(),
+ Memb2.begin(), Memb2.end(),
+ std::inserter(Intersection, Intersection.begin()));
+
+ // Skip disjoint class pairs.
+ if (Intersection.empty())
+ continue;
+
+ // If RC1 and RC2 have different spill sizes or alignments, use the
+ // larger size for sub-classing. If they are equal, prefer RC1.
+ if (RC2->SpillSize > RC1->SpillSize ||
+ (RC2->SpillSize == RC1->SpillSize &&
+ RC2->SpillAlignment > RC1->SpillAlignment))
+ std::swap(RC1, RC2);
+
+ getOrCreateSubClass(RC1, &Intersection,
+ RC1->getName() + "_and_" + RC2->getName());
+ }
+}
+
// Infer missing register classes.
//
// For every register class RC, make sure that the set of registers in RC with
RC.getName() + "_with_" + I->first->getName());
RC.setSubClassWithSubReg(SubIdx, SubRC);
}
+
+ // Synthesize answers for getCommonSubClass().
+ inferCommonSubClass(&RC);
}
}