llvm/lib/Target/R600/SIMachineFunctionInfo.cpp
2014-08-21 20:40:56 +00:00

79 lines
2.4 KiB
C++

//===-- SIMachineFunctionInfo.cpp - SI Machine Function Info -------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
/// \file
//===----------------------------------------------------------------------===//
#include "SIMachineFunctionInfo.h"
#include "SIInstrInfo.h"
#include "SIRegisterInfo.h"
#include "llvm/CodeGen/MachineFrameInfo.h"
#include "llvm/CodeGen/MachineRegisterInfo.h"
#include "llvm/IR/Function.h"
#include "llvm/IR/LLVMContext.h"
#define MAX_LANES 64
using namespace llvm;
// Pin the vtable to this file.
void SIMachineFunctionInfo::anchor() {}
SIMachineFunctionInfo::SIMachineFunctionInfo(const MachineFunction &MF)
: AMDGPUMachineFunction(MF),
PSInputAddr(0),
NumUserSGPRs(0) { }
/// \brief Returns a register that is not used at any point in the function.
/// If all registers are used, then this function will return
// AMDGPU::NoRegister.
static unsigned findUnusedVGPR(const MachineRegisterInfo &MRI) {
const TargetRegisterClass *RC = &AMDGPU::VGPR_32RegClass;
for (TargetRegisterClass::iterator I = RC->begin(), E = RC->end();
I != E; ++I) {
if (!MRI.isPhysRegUsed(*I))
return *I;
}
return AMDGPU::NoRegister;
}
SIMachineFunctionInfo::SpilledReg SIMachineFunctionInfo::getSpilledReg(
MachineFunction *MF,
unsigned FrameIndex,
unsigned SubIdx) {
const MachineFrameInfo *FrameInfo = MF->getFrameInfo();
MachineRegisterInfo &MRI = MF->getRegInfo();
int64_t Offset = FrameInfo->getObjectOffset(FrameIndex);
Offset += SubIdx * 4;
unsigned LaneVGPRIdx = Offset / (64 * 4);
unsigned Lane = (Offset / 4) % 64;
struct SpilledReg Spill;
if (!LaneVGPRs.count(LaneVGPRIdx)) {
unsigned LaneVGPR = findUnusedVGPR(MRI);
LaneVGPRs[LaneVGPRIdx] = LaneVGPR;
MRI.setPhysRegUsed(LaneVGPR);
// Add this register as live-in to all blocks to avoid machine verifer
// complaining about use of an undefined physical register.
for (MachineFunction::iterator BI = MF->begin(), BE = MF->end();
BI != BE; ++BI) {
BI->addLiveIn(LaneVGPR);
}
}
Spill.VGPR = LaneVGPRs[LaneVGPRIdx];
Spill.Lane = Lane;
return Spill;
}