mirror of
https://github.com/c64scene-ar/llvm-6502.git
synced 2024-12-25 14:32:53 +00:00
dd479e9769
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@121584 91177308-0d34-0410-b5e6-96231b3b80d8
69 lines
2.3 KiB
C++
69 lines
2.3 KiB
C++
//===-- 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 "VirtRegMap.h"
|
|
#include "llvm/CodeGen/MachineRegisterInfo.h"
|
|
|
|
using namespace llvm;
|
|
|
|
// Compare VirtRegMap::getRegAllocPref().
|
|
AllocationOrder::AllocationOrder(unsigned VirtReg,
|
|
const VirtRegMap &VRM,
|
|
const BitVector &ReservedRegs)
|
|
: Pos(0), Reserved(ReservedRegs) {
|
|
const TargetRegisterClass *RC = VRM.getRegInfo().getRegClass(VirtReg);
|
|
std::pair<unsigned, unsigned> HintPair =
|
|
VRM.getRegInfo().getRegAllocationHint(VirtReg);
|
|
|
|
// HintPair.second is a register, phys or virt.
|
|
Hint = HintPair.second;
|
|
|
|
// Translate to physreg, or 0 if not assigned yet.
|
|
if (Hint && TargetRegisterInfo::isVirtualRegister(Hint))
|
|
Hint = VRM.getPhys(Hint);
|
|
|
|
// The remaining allocation order may depend on the hint.
|
|
tie(Begin, End) = VRM.getTargetRegInfo()
|
|
.getAllocationOrder(RC, HintPair.first, Hint, VRM.getMachineFunction());
|
|
|
|
// Target-dependent hints require resolution.
|
|
if (HintPair.first)
|
|
Hint = VRM.getTargetRegInfo().ResolveRegAllocHint(HintPair.first, Hint,
|
|
VRM.getMachineFunction());
|
|
|
|
// The hint must be a valid physreg for allocation.
|
|
if (Hint && (!TargetRegisterInfo::isPhysicalRegister(Hint) ||
|
|
!RC->contains(Hint) || ReservedRegs.test(Hint)))
|
|
Hint = 0;
|
|
}
|
|
|
|
unsigned AllocationOrder::next() {
|
|
// First take the hint.
|
|
if (!Pos) {
|
|
Pos = Begin;
|
|
if (Hint)
|
|
return Hint;
|
|
}
|
|
// Then look at the order from TRI.
|
|
while(Pos != End) {
|
|
unsigned Reg = *Pos++;
|
|
if (Reg != Hint && !Reserved.test(Reg))
|
|
return Reg;
|
|
}
|
|
return 0;
|
|
}
|