1 //===- TargetRegisterInfo.cpp - Target Register Information Implementation ===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This file implements the TargetRegisterInfo interface.
12 //===----------------------------------------------------------------------===//
14 #include "llvm/Target/TargetMachine.h"
15 #include "llvm/Target/TargetRegisterInfo.h"
16 #include "llvm/CodeGen/MachineFunction.h"
17 #include "llvm/CodeGen/MachineFrameInfo.h"
18 #include "llvm/ADT/BitVector.h"
19 #include "llvm/Support/raw_ostream.h"
23 TargetRegisterInfo::TargetRegisterInfo(const TargetRegisterDesc *D, unsigned NR,
24 regclass_iterator RCB, regclass_iterator RCE,
25 const char *const *subregindexnames,
27 : Desc(D), SubRegIndexNames(subregindexnames), NumRegs(NR),
28 RegClassBegin(RCB), RegClassEnd(RCE) {
29 assert(isPhysicalRegister(NumRegs) &&
30 "Target has too many physical registers!");
32 CallFrameSetupOpcode = CFSO;
33 CallFrameDestroyOpcode = CFDO;
36 TargetRegisterInfo::~TargetRegisterInfo() {}
38 void PrintReg::print(raw_ostream &OS) const {
41 else if (TargetRegisterInfo::isStackSlot(Reg))
42 OS << "SS#" << TargetRegisterInfo::stackSlot2Index(Reg);
43 else if (TargetRegisterInfo::isVirtualRegister(Reg))
44 OS << "%vreg" << TargetRegisterInfo::virtReg2Index(Reg);
45 else if (TRI && Reg < TRI->getNumRegs())
46 OS << '%' << TRI->getName(Reg);
48 OS << "%physreg" << Reg;
51 OS << ':' << TRI->getSubRegIndexName(SubIdx);
53 OS << ":sub(" << SubIdx << ')';
57 /// getMinimalPhysRegClass - Returns the Register Class of a physical
58 /// register of the given type, picking the most sub register class of
59 /// the right type that contains this physreg.
60 const TargetRegisterClass *
61 TargetRegisterInfo::getMinimalPhysRegClass(unsigned reg, EVT VT) const {
62 assert(isPhysicalRegister(reg) && "reg must be a physical register");
64 // Pick the most sub register class of the right type that contains
66 const TargetRegisterClass* BestRC = 0;
67 for (regclass_iterator I = regclass_begin(), E = regclass_end(); I != E; ++I){
68 const TargetRegisterClass* RC = *I;
69 if ((VT == MVT::Other || RC->hasType(VT)) && RC->contains(reg) &&
70 (!BestRC || BestRC->hasSubClass(RC)))
74 assert(BestRC && "Couldn't find the register class");
78 /// getAllocatableSetForRC - Toggle the bits that represent allocatable
79 /// registers for the specific register class.
80 static void getAllocatableSetForRC(const MachineFunction &MF,
81 const TargetRegisterClass *RC, BitVector &R){
82 ArrayRef<unsigned> Order = RC->getRawAllocationOrder(MF);
83 for (unsigned i = 0; i != Order.size(); ++i)
87 BitVector TargetRegisterInfo::getAllocatableSet(const MachineFunction &MF,
88 const TargetRegisterClass *RC) const {
89 BitVector Allocatable(NumRegs);
91 getAllocatableSetForRC(MF, RC, Allocatable);
93 for (TargetRegisterInfo::regclass_iterator I = regclass_begin(),
94 E = regclass_end(); I != E; ++I)
95 if ((*I)->isAllocatable())
96 getAllocatableSetForRC(MF, *I, Allocatable);
99 // Mask out the reserved registers
100 BitVector Reserved = getReservedRegs(MF);
101 Allocatable &= Reserved.flip();
106 const TargetRegisterClass *
107 llvm::getCommonSubClass(const TargetRegisterClass *A,
108 const TargetRegisterClass *B) {
109 // First take care of the trivial cases
115 // If B is a subclass of A, it will be handled in the loop below
116 if (B->hasSubClass(A))
119 const TargetRegisterClass *Best = 0;
120 for (TargetRegisterClass::sc_iterator I = A->subclasses_begin();
121 const TargetRegisterClass *X = *I; ++I) {
123 return B; // B is a subclass of A
125 // X must be a common subclass of A and B
126 if (!B->hasSubClass(X))
129 // A superclass is definitely better.
130 if (!Best || Best->hasSuperClass(X)) {
135 // A subclass is definitely worse
136 if (Best->hasSubClass(X))
139 // Best and *I have no super/sub class relation - pick the larger class, or
140 // the smaller spill size.
141 int nb = std::distance(Best->begin(), Best->end());
142 int ni = std::distance(X->begin(), X->end());
143 if (ni>nb || (ni==nb && X->getSize() < Best->getSize()))