#include "CodeGenRegisters.h"
#include "CodeGenInstruction.h"
+#include <algorithm>
#include <iosfwd>
#include <map>
}
/// getRegisterClassForRegister - Find the register class that contains the
- /// specified physical register. If there register exists in multiple
- /// register classes or is not in a register class, return null.
+ /// specified physical register. If the register is not in a register
+ /// class, return null. If the register is in multiple classes, and the
+ /// classes have a superset-subset relationship and the same set of
+ /// types, return the superclass. Otherwise return null.
const CodeGenRegisterClass *getRegisterClassForRegister(Record *R) const {
const std::vector<CodeGenRegisterClass> &RCs = getRegisterClasses();
const CodeGenRegisterClass *FoundRC = 0;
for (unsigned i = 0, e = RCs.size(); i != e; ++i) {
const CodeGenRegisterClass &RC = RegisterClasses[i];
for (unsigned ei = 0, ee = RC.Elements.size(); ei != ee; ++ei) {
- if (R == RC.Elements[ei]) {
- if (FoundRC) return 0; // In multiple RC's
+ if (R != RC.Elements[ei])
+ continue;
+
+ // If a register's classes have different types, return null.
+ if (FoundRC && RC.getValueTypes() != FoundRC->getValueTypes())
+ return 0;
+
+ // If this is the first class that contains the register,
+ // make a note of it and go on to the next class.
+ if (!FoundRC) {
+ FoundRC = &RC;
+ break;
+ }
+
+ std::vector<Record *> Elements(RC.Elements);
+ std::vector<Record *> FoundElements(FoundRC->Elements);
+ std::sort(Elements.begin(), Elements.end());
+ std::sort(FoundElements.begin(), FoundElements.end());
+
+ // Check to see if the previously found class that contains
+ // the register is a subclass of the current class. If so,
+ // prefer the superclass.
+ if (std::includes(Elements.begin(), Elements.end(),
+ FoundElements.begin(), FoundElements.end())) {
FoundRC = &RC;
break;
}
+
+ // Check to see if the previously found class that contains
+ // the register is a superclass of the current class. If so,
+ // prefer the superclass.
+ if (std::includes(FoundElements.begin(), FoundElements.end(),
+ Elements.begin(), Elements.end()))
+ break;
+
+ // Multiple classes, and neither is a superclass of the other.
+ // Return null.
+ return 0;
}
}
return FoundRC;