#include "llvm/Analysis/AliasAnalysis.h"
#include "llvm/Analysis/BranchProbabilityInfo.h"
#include "llvm/Analysis/CFG.h"
-#include "llvm/Analysis/LibCallSemantics.h"
+#include "llvm/Analysis/EHPersonalities.h"
#include "llvm/Analysis/TargetLibraryInfo.h"
#include "llvm/CodeGen/Analysis.h"
#include "llvm/CodeGen/FastISel.h"
return;
IS.OptLevel = NewOptLevel;
IS.TM.setOptLevel(NewOptLevel);
- SavedFastISel = IS.TM.Options.EnableFastISel;
- if (NewOptLevel == CodeGenOpt::None)
- IS.TM.setFastISel(true);
DEBUG(dbgs() << "\nChanging optimization level for Function "
<< IS.MF->getFunction()->getName() << "\n");
DEBUG(dbgs() << "\tBefore: -O" << SavedOptLevel
<< " ; After: -O" << NewOptLevel << "\n");
+ SavedFastISel = IS.TM.Options.EnableFastISel;
+ if (NewOptLevel == CodeGenOpt::None) {
+ IS.TM.setFastISel(IS.TM.getO0WantsFastISel());
+ DEBUG(dbgs() << "\tFastISel is "
+ << (IS.TM.Options.EnableFastISel ? "enabled" : "disabled")
+ << "\n");
+ }
}
~OptLevelChanger() {
///
static void SplitCriticalSideEffectEdges(Function &Fn) {
// Loop for blocks with phi nodes.
- for (Function::iterator BB = Fn.begin(), E = Fn.end(); BB != E; ++BB) {
- PHINode *PN = dyn_cast<PHINode>(BB->begin());
+ for (BasicBlock &BB : Fn) {
+ PHINode *PN = dyn_cast<PHINode>(BB.begin());
if (!PN) continue;
ReprocessBlock:
// are potentially trapping constant expressions. Constant expressions are
// the only potentially trapping value that can occur as the argument to a
// PHI.
- for (BasicBlock::iterator I = BB
->begin(); (PN = dyn_cast<PHINode>(I)); ++I)
+ for (BasicBlock::iterator I = BB
.begin(); (PN = dyn_cast<PHINode>(I)); ++I)
for (unsigned i = 0, e = PN->getNumIncomingValues(); i != e; ++i) {
ConstantExpr *CE = dyn_cast<ConstantExpr>(PN->getIncomingValue(i));
if (!CE || !CE->canTrap()) continue;
// Okay, we have to split this edge.
SplitCriticalEdge(
- Pred->getTerminator(), GetSuccessorNumber(Pred, BB),
+ Pred->getTerminator(), GetSuccessorNumber(Pred, &BB),
CriticalEdgeSplittingOptions().setMergeIdenticalEdges());
goto ReprocessBlock;
}
MF->setHasInlineAsm(false);
+ FuncInfo->SplitCSR = false;
+ SmallVector<MachineBasicBlock*, 4> Returns;
+
+ // We split CSR if the target supports it for the given function
+ // and the function has only return exits.
+ if (TLI->supportSplitCSR(MF)) {
+ FuncInfo->SplitCSR = true;
+
+ // Collect all the return blocks.
+ for (const BasicBlock &BB : Fn) {
+ if (!succ_empty(&BB))
+ continue;
+
+ const TerminatorInst *Term = BB.getTerminator();
+ if (isa<UnreachableInst>(Term))
+ continue;
+ if (isa<ReturnInst>(Term)) {
+ Returns.push_back(FuncInfo->MBBMap[&BB]);
+ continue;
+ }
+
+ // Bail out if the exit block is not Return nor Unreachable.
+ FuncInfo->SplitCSR = false;
+ break;
+ }
+ }
+
+ MachineBasicBlock *EntryMBB = &MF->front();
+ if (FuncInfo->SplitCSR)
+ // This performs initialization so lowering for SplitCSR will be correct.
+ TLI->initializeSplitCSR(EntryMBB);
+
SelectAllBasicBlocks(Fn);
// If the first basic block in the function has live ins that need to be
// copied into vregs, emit the copies into the top of the block before
// emitting the code for the block.
- MachineBasicBlock *EntryMBB = MF->begin();
const TargetRegisterInfo &TRI = *MF->getSubtarget().getRegisterInfo();
RegInfo->EmitLiveInCopies(EntryMBB, TRI, *TII);
+ // Insert copies in the entry block and the return blocks.
+ if (FuncInfo->SplitCSR)
+ TLI->insertCopiesSplitCSR(EntryMBB, Returns);
+
DenseMap<unsigned, unsigned> LiveInMap;
if (!FuncInfo->ArgDbgValues.empty())
for (MachineRegisterInfo::livein_iterator LI = RegInfo->livein_begin(),
MRI.replaceRegWith(From, To);
}
+ if (TLI->hasCopyImplyingStackAdjustment(MF))
+ MFI->setHasCopyImplyingStackAdjustment(true);
+
// Freeze the set of reserved registers now that MachineFrameInfo has been
// set up. All the information required by getReservedRegs() should be
// available now.
// at this point.
FuncInfo->clear();
+ // XXX-update: Right after instruction selection, check through the
+ // intentionally added fake conditional branches and mark them as unremovable.
+ for (auto& MBB : *MF) {
+ // Check whether MBB has two successors which only contains an unconditional
+ // branch to the same destination.
+ if (MBB.succ_size() != 2 ||
+ !MBB.getLastNonDebugInstr()->isUnconditionalBranch()) {
+ continue;
+ }
+ auto MBBSuccIter = MBB.succ_begin();
+ auto* Succ1 = *MBBSuccIter;
+ MBBSuccIter++;
+ auto* Succ2 = *MBBSuccIter;
+
+ MachineBasicBlock* Succ1Succ = nullptr;
+ MachineBasicBlock* Succ2Succ = nullptr;
+ if ((Succ1->size() == 1 && Succ1->begin()->isUnconditionalBranch()) ||
+ (Succ1->size() == 0)) {
+ Succ1Succ = *Succ1->succ_begin();
+ }
+ if ((Succ2->size() == 1 && Succ2->begin()->isUnconditionalBranch()) ||
+ (Succ2->size() == 0)) {
+ Succ2Succ = *Succ2->succ_begin();
+ }
+
+ bool HasCommonDest = Succ1Succ && Succ1Succ == Succ2Succ;
+ if (HasCommonDest) {
+ auto MBBIter = MBB.end();
+ std::advance(MBBIter, -2);
+ assert(MBBIter->isConditionalBranch());
+ MBBIter->disableCanEliminateMachineInstr();
+ MBB.disableCanEliminateMachineBB();
+ Succ1->disableCanEliminateMachineBB();
+ Succ2->disableCanEliminateMachineBB();
+ Succ1Succ->disableCanEliminateMachineBB();
+ DEBUG(dbgs() << "Mark as unremovable machine basic block: " << MBB
+ << "\nMark as unremovable branch instruction: " << *MBBIter
+ << "\n");
+ }
+ }
+
DEBUG(dbgs() << "*** MachineFunction at end of ISel ***\n");
DEBUG(MF->print(dbgs()));
// graph) and preceding back toward the beginning (the entry
// node).
while (ISelPosition != CurDAG->allnodes_begin()) {
- SDNode *Node = --ISelPosition;
+ SDNode *Node = &*--ISelPosition;
// Skip dead nodes. DAGCombiner is expected to eliminate all dead nodes,
// but there are currently some corner cases that it misses. Also, this
// makes it theoretically possible to disable the DAGCombiner.
PostprocessISelDAG();
}
+static bool hasExceptionPointerOrCodeUser(const CatchPadInst *CPI) {
+ for (const User *U : CPI->users()) {
+ if (const IntrinsicInst *EHPtrCall = dyn_cast<IntrinsicInst>(U)) {
+ Intrinsic::ID IID = EHPtrCall->getIntrinsicID();
+ if (IID == Intrinsic::eh_exceptionpointer ||
+ IID == Intrinsic::eh_exceptioncode)
+ return true;
+ }
+ }
+ return false;
+}
+
/// PrepareEHLandingPad - Emit an EH_LABEL, set up live-in registers, and
/// do other setup for EH landing-pad blocks.
bool SelectionDAGISel::PrepareEHLandingPad() {
MachineBasicBlock *MBB = FuncInfo->MBB;
-
+ const Constant *PersonalityFn = FuncInfo->Fn->getPersonalityFn();
+ const BasicBlock *LLVMBB = MBB->getBasicBlock();
const TargetRegisterClass *PtrRC =
TLI->getRegClassFor(TLI->getPointerTy(CurDAG->getDataLayout()));
+ // Catchpads have one live-in register, which typically holds the exception
+ // pointer or code.
+ if (const auto *CPI = dyn_cast<CatchPadInst>(LLVMBB->getFirstNonPHI())) {
+ if (hasExceptionPointerOrCodeUser(CPI)) {
+ // Get or create the virtual register to hold the pointer or code. Mark
+ // the live in physreg and copy into the vreg.
+ MCPhysReg EHPhysReg = TLI->getExceptionPointerRegister(PersonalityFn);
+ assert(EHPhysReg && "target lacks exception pointer register");
+ MBB->addLiveIn(EHPhysReg);
+ unsigned VReg = FuncInfo->getCatchPadExceptionPointerVReg(CPI, PtrRC);
+ BuildMI(*MBB, FuncInfo->InsertPt, SDB->getCurDebugLoc(),
+ TII->get(TargetOpcode::COPY), VReg)
+ .addReg(EHPhysReg, RegState::Kill);
+ }
+ return true;
+ }
+
+ if (!LLVMBB->isLandingPad())
+ return true;
+
// Add a label to mark the beginning of the landing pad. Deletion of the
// landing pad can thus be detected via the MachineModuleInfo.
MCSymbol *Label = MF->getMMI().addLandingPad(MBB);
BuildMI(*MBB, FuncInfo->InsertPt, SDB->getCurDebugLoc(), II)
.addSym(Label);
- // If this is an MSVC-style personality function, we need to split the landing
- // pad into several BBs.
- const BasicBlock *LLVMBB = MBB->getBasicBlock();
- const Constant *Personality = MF->getFunction()->getPersonalityFn();
- if (const auto *PF = dyn_cast<Function>(Personality->stripPointerCasts()))
- MF->getMMI().addPersonality(PF);
- EHPersonality PersonalityType = classifyEHPersonality(Personality);
-
- if (isMSVCEHPersonality(PersonalityType)) {
- SmallVector<MachineBasicBlock *, 4> ClauseBBs;
- const IntrinsicInst *ActionsCall =
- dyn_cast<IntrinsicInst>(LLVMBB->getFirstInsertionPt());
- // Get all invoke BBs that unwind to this landingpad.
- SmallVector<MachineBasicBlock *, 4> InvokeBBs(MBB->pred_begin(),
- MBB->pred_end());
- if (ActionsCall && ActionsCall->getIntrinsicID() == Intrinsic::eh_actions) {
- // If this is a call to llvm.eh.actions followed by indirectbr, then we've
- // run WinEHPrepare, and we should remove this block from the machine CFG.
- // Mark the targets of the indirectbr as landingpads instead.
- for (const BasicBlock *LLVMSucc : successors(LLVMBB)) {
- MachineBasicBlock *ClauseBB = FuncInfo->MBBMap[LLVMSucc];
- // Add the edge from the invoke to the clause.
- for (MachineBasicBlock *InvokeBB : InvokeBBs)
- InvokeBB->addSuccessor(ClauseBB);
-
- // Mark the clause as a landing pad or MI passes will delete it.
- ClauseBB->setIsEHPad();
- }
- }
-
- // Remove the edge from the invoke to the lpad.
- for (MachineBasicBlock *InvokeBB : InvokeBBs)
- InvokeBB->removeSuccessor(MBB);
-
- // Don't select instructions for the landingpad.
- return false;
- }
-
// Mark exception register as live in.
- if (unsigned Reg = TLI->getExceptionPointerRegister())
+ if (unsigned Reg = TLI->getExceptionPointerRegister(PersonalityFn))
FuncInfo->ExceptionPointerVirtReg = MBB->addLiveIn(Reg, PtrRC);
// Mark exception selector register as live in.
- if (unsigned Reg = TLI->getExceptionSelectorRegister())
+ if (unsigned Reg = TLI->getExceptionSelectorRegister(PersonalityFn))
FuncInfo->ExceptionSelectorVirtReg = MBB->addLiveIn(Reg, PtrRC);
return true;
FuncInfo->VisitedBBs.insert(LLVMBB);
}
- BasicBlock::const_iterator const Begin = LLVMBB->getFirstNonPHI();
+ BasicBlock::const_iterator const Begin =
+ LLVMBB->getFirstNonPHI()->getIterator();
BasicBlock::const_iterator const End = LLVMBB->end();
BasicBlock::const_iterator BI = End;
// Setup an EH landing-pad block.
FuncInfo->ExceptionPointerVirtReg = 0;
FuncInfo->ExceptionSelectorVirtReg = 0;
- if (LLVMBB->isLandingPad())
+ if (LLVMBB->isEHPad())
if (!PrepareEHLandingPad())
continue;
-
// Before doing SelectionDAG ISel, see if FastISel has been requested.
if (FastIS) {
FastIS->startNewBlock();
unsigned NumFastIselRemaining = std::distance(Begin, End);
// Do FastISel on as many instructions as possible.
for (; BI != Begin; --BI) {
- const Instruction *Inst = std::prev(BI);
+ const Instruction *Inst = &*std::prev(BI);
// If we no longer require this instruction, skip it.
if (isFoldedOrDeadInstruction(Inst, FuncInfo)) {
// then see if there is a load right before the selected instructions.
// Try to fold the load if so.
const Instruction *BeforeInst = Inst;
- while (BeforeInst != Begin) {
- BeforeInst = std::prev(BasicBlock::const_iterator(BeforeInst));
+ while (BeforeInst != &*Begin) {
+ BeforeInst = &*std::prev(BasicBlock::const_iterator(BeforeInst));
if (!isFoldedOrDeadInstruction(BeforeInst, FuncInfo))
break;
}
bool HadTailCall = false;
MachineBasicBlock::iterator SavedInsertPt = FuncInfo->InsertPt;
- SelectBasicBlock(Inst, BI, HadTailCall);
+ SelectBasicBlock(Inst->getIterator(), BI, HadTailCall);
// If the call was emitted as a tail call, we're done with the block.
// We also need to delete any previously emitted instructions.
CodeGenAndEmitDAG();
}
- uint32_t UnhandledWeight = SDB->BitTestCases[i].Weight;
-
+ BranchProbability UnhandledProb = SDB->BitTestCases[i].Prob;
for (unsigned j = 0, ej = SDB->BitTestCases[i].Cases.size(); j != ej; ++j) {
- UnhandledWeight -= SDB->BitTestCases[i].Cases[j].ExtraWeight;
+ UnhandledProb -= SDB->BitTestCases[i].Cases[j].ExtraProb;
// Set the current basic block to the mbb we wish to insert the code into
FuncInfo->MBB = SDB->BitTestCases[i].Cases[j].ThisBB;
FuncInfo->InsertPt = FuncInfo->MBB->end();
SDB->visitBitTestCase(SDB->BitTestCases[i],
NextMBB,
- UnhandledWeight,
+ UnhandledProb,
SDB->BitTestCases[i].Reg,
SDB->BitTestCases[i].Cases[j],
FuncInfo->MBB);
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