//===-- SIFixSGPRLiveRanges.cpp - Fix SGPR live ranges ----------------------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
/// \file
/// SALU instructions ignore control flow, so we need to modify the live ranges
/// of the registers they define.
///
/// The strategy is to view the entire program as if it were a single basic
/// block and calculate the intervals accordingly. We implement this
/// by walking this list of segments for each LiveRange and setting the
/// end of each segment equal to the start of the segment that immediately
/// follows it.
#include "AMDGPU.h"
#include "SIRegisterInfo.h"
#include "llvm/CodeGen/LiveIntervalAnalysis.h"
#include "llvm/CodeGen/MachineFunctionPass.h"
#include "llvm/CodeGen/MachineRegisterInfo.h"
#include "llvm/Support/Debug.h"
#include "llvm/Target/TargetMachine.h"
using namespace llvm;
#define DEBUG_TYPE "si-fix-sgpr-live-ranges"
namespace {
class SIFixSGPRLiveRanges : public MachineFunctionPass {
public:
static char ID;
public:
SIFixSGPRLiveRanges() : MachineFunctionPass(ID) {
initializeSIFixSGPRLiveRangesPass(*PassRegistry::getPassRegistry());
}
virtual bool runOnMachineFunction(MachineFunction &MF) override;
virtual const char *getPassName() const override {
return "SI Fix SGPR live ranges";
}
virtual void getAnalysisUsage(AnalysisUsage &AU) const override {
AU.addRequired<LiveIntervals>();
AU.addPreserved<LiveIntervals>();
AU.addPreserved<SlotIndexes>();
AU.setPreservesCFG();
MachineFunctionPass::getAnalysisUsage(AU);
}
};
} // End anonymous namespace.
INITIALIZE_PASS_BEGIN(SIFixSGPRLiveRanges, DEBUG_TYPE,
"SI Fix SGPR Live Ranges", false, false)
INITIALIZE_PASS_DEPENDENCY(LiveIntervals)
INITIALIZE_PASS_END(SIFixSGPRLiveRanges, DEBUG_TYPE,
"SI Fix SGPR Live Ranges", false, false)
char SIFixSGPRLiveRanges::ID = 0;
char &llvm::SIFixSGPRLiveRangesID = SIFixSGPRLiveRanges::ID;
FunctionPass *llvm::createSIFixSGPRLiveRangesPass() {
return new SIFixSGPRLiveRanges();
}
bool SIFixSGPRLiveRanges::runOnMachineFunction(MachineFunction &MF) {
MachineRegisterInfo &MRI = MF.getRegInfo();
const SIRegisterInfo *TRI = static_cast<const SIRegisterInfo *>(
MF.getTarget().getRegisterInfo());
LiveIntervals *LIS = &getAnalysis<LiveIntervals>();
for (MachineFunction::iterator BI = MF.begin(), BE = MF.end();
BI != BE; ++BI) {
MachineBasicBlock &MBB = *BI;
for (MachineBasicBlock::iterator I = MBB.begin(), E = MBB.end();
I != E; ++I) {
MachineInstr &MI = *I;
MachineOperand *ExecUse = MI.findRegisterUseOperand(AMDGPU::EXEC);
if (ExecUse)
continue;
for (const MachineOperand &Def : MI.operands()) {
if (!Def.isReg() || !Def.isDef() ||!TargetRegisterInfo::isVirtualRegister(Def.getReg()))
continue;
const TargetRegisterClass *RC = MRI.getRegClass(Def.getReg());
if (!TRI->isSGPRClass(RC))
continue;
LiveInterval &LI = LIS->getInterval(Def.getReg());
for (unsigned i = 0, e = LI.size() - 1; i != e; ++i) {
LiveRange::Segment &Seg = LI.segments[i];
LiveRange::Segment &Next = LI.segments[i + 1];
Seg.end = Next.start;
}
}
}
}
return false;
}