llvm-6502/include/llvm/CodeGen/SSARegMap.h
Evan Cheng 32dfbeada7 EXTRACT_SUBREG coalescing support. The coalescer now treats EXTRACT_SUBREG like
(almost) a register copy. However, it always coalesced to the register of the
RHS (the super-register). All uses of the result of a EXTRACT_SUBREG are sub-
register uses which adds subtle complications to load folding, spiller rewrite,
etc.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@42899 91177308-0d34-0410-b5e6-96231b3b80d8
2007-10-12 08:50:34 +00:00

75 lines
2.2 KiB
C++

//===-- llvm/CodeGen/SSARegMap.h --------------------------------*- C++ -*-===//
//
// The LLVM Compiler Infrastructure
//
// This file was developed by the LLVM research group and is distributed under
// the University of Illinois Open Source License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// Map register numbers to register classes that are correctly sized (typed) to
// hold the information. Assists register allocation. Contained by
// MachineFunction, should be deleted by register allocator when it is no
// longer needed.
//
//===----------------------------------------------------------------------===//
#ifndef LLVM_CODEGEN_SSAREGMAP_H
#define LLVM_CODEGEN_SSAREGMAP_H
#include "llvm/Target/MRegisterInfo.h"
#include "llvm/ADT/IndexedMap.h"
namespace llvm {
class TargetRegisterClass;
class SSARegMap {
IndexedMap<const TargetRegisterClass*, VirtReg2IndexFunctor> RegClassMap;
IndexedMap<std::pair<unsigned, unsigned>, VirtReg2IndexFunctor> RegSubIdxMap;
unsigned NextRegNum;
public:
SSARegMap() : NextRegNum(MRegisterInfo::FirstVirtualRegister) { }
const TargetRegisterClass* getRegClass(unsigned Reg) {
return RegClassMap[Reg];
}
/// createVirtualRegister - Create and return a new virtual register in the
/// function with the specified register class.
///
unsigned createVirtualRegister(const TargetRegisterClass *RegClass) {
assert(RegClass && "Cannot create register without RegClass!");
RegClassMap.grow(NextRegNum);
RegClassMap[NextRegNum] = RegClass;
RegSubIdxMap.grow(NextRegNum);
RegSubIdxMap[NextRegNum] = std::make_pair(0,0);
return NextRegNum++;
}
unsigned getLastVirtReg() const {
return NextRegNum - 1;
}
void setIsSubRegister(unsigned Reg, unsigned SuperReg, unsigned SubIdx) {
RegSubIdxMap[Reg] = std::make_pair(SuperReg, SubIdx);
}
bool isSubRegister(unsigned Reg) const {
return RegSubIdxMap[Reg].first != 0;
}
unsigned getSuperRegister(unsigned Reg) const {
return RegSubIdxMap[Reg].first;
}
unsigned getSubRegisterIndex(unsigned Reg) const {
return RegSubIdxMap[Reg].second;
}
};
} // End llvm namespace
#endif