TargetRegisterInfo::~TargetRegisterInfo() {}
+namespace {
+ // Sort according to super- / sub- class relations.
+ // i.e. super- register class < sub- register class.
+ struct RCCompare {
+ bool operator()(const TargetRegisterClass* const &LHS,
+ const TargetRegisterClass* const &RHS) {
+ return RHS->hasSuperClass(LHS);
+ }
+ };
+}
+
/// getPhysicalRegisterRegClass - Returns the Register Class of a physical
/// register of the given type. If type is MVT::Other, then just return any
/// register class the register belongs to.
TargetRegisterInfo::getPhysicalRegisterRegClass(unsigned reg,
MVT::ValueType VT) const {
assert(isPhysicalRegister(reg) && "reg must be a physical register");
+
// Pick the register class of the right type that contains this physreg.
- for (regclass_iterator I = regclass_begin(), E = regclass_end(); I != E; ++I)
- if ((VT == MVT::Other || (*I)->hasType(VT))
- && (*I)->contains(reg))
- return *I;
+ SmallVector<const TargetRegisterClass*, 4> RCs;
+ for (regclass_iterator I = regclass_begin(), E = regclass_end(); I != E; ++I) {
+ if ((VT == MVT::Other || (*I)->hasType(VT)) && (*I)->contains(reg))
+ RCs.push_back(*I);
+ }
+
+ if (RCs.size() == 1)
+ return RCs[0];
+
+ if (RCs.size()) {
+ // Multiple compatible register classes. Get the super- class.
+ std::stable_sort(RCs.begin(), RCs.end(), RCCompare());
+ return RCs[0];
+ }
+
assert(false && "Couldn't find the register class");
return 0;
}