llvm-6502/lib/CodeGen/AllocationOrder.cpp

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//===-- llvm/CodeGen/AllocationOrder.cpp - Allocation Order ---------------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file implements an allocation order for virtual registers.
//
// The preferred allocation order for a virtual register depends on allocation
// hints and target hooks. The AllocationOrder class encapsulates all of that.
//
//===----------------------------------------------------------------------===//
#include "AllocationOrder.h"
#include "llvm/CodeGen/MachineFunction.h"
#include "llvm/CodeGen/MachineRegisterInfo.h"
#include "llvm/CodeGen/RegisterClassInfo.h"
#include "llvm/CodeGen/VirtRegMap.h"
#include "llvm/Support/Debug.h"
#include "llvm/Support/raw_ostream.h"
using namespace llvm;
#define DEBUG_TYPE "regalloc"
// Compare VirtRegMap::getRegAllocPref().
AllocationOrder::AllocationOrder(unsigned VirtReg,
const VirtRegMap &VRM,
const RegisterClassInfo &RegClassInfo)
: Pos(0) {
const MachineFunction &MF = VRM.getMachineFunction();
const TargetRegisterInfo *TRI = &VRM.getTargetRegInfo();
Order = RegClassInfo.getOrder(MF.getRegInfo().getRegClass(VirtReg));
TRI->getRegAllocationHints(VirtReg, Order, Hints, MF, &VRM);
rewind();
DEBUG({
if (!Hints.empty()) {
dbgs() << "hints:";
for (unsigned I = 0, E = Hints.size(); I != E; ++I)
dbgs() << ' ' << PrintReg(Hints[I], TRI);
dbgs() << '\n';
}
});
#ifndef NDEBUG
for (unsigned I = 0, E = Hints.size(); I != E; ++I)
assert(std::find(Order.begin(), Order.end(), Hints[I]) != Order.end() &&
"Target hint is outside allocation order.");
#endif
}