#include "llvm/Function.h"
#include "llvm/InlineAsm.h"
#include "llvm/Instructions.h"
+#include "llvm/IntrinsicInst.h"
#include "llvm/Pass.h"
-#include "llvm/Target/TargetAsmInfo.h"
+#include "llvm/Analysis/ProfileInfo.h"
#include "llvm/Target/TargetData.h"
#include "llvm/Target/TargetLowering.h"
-#include "llvm/Target/TargetMachine.h"
+#include "llvm/Transforms/Utils/AddrModeMatcher.h"
#include "llvm/Transforms/Utils/BasicBlockUtils.h"
#include "llvm/Transforms/Utils/Local.h"
+#include "llvm/Transforms/Utils/BuildLibCalls.h"
#include "llvm/ADT/DenseMap.h"
#include "llvm/ADT/SmallSet.h"
+#include "llvm/Assembly/Writer.h"
#include "llvm/Support/CallSite.h"
-#include "llvm/Support/Compiler.h"
#include "llvm/Support/Debug.h"
#include "llvm/Support/GetElementPtrTypeIterator.h"
#include "llvm/Support/PatternMatch.h"
+#include "llvm/Support/raw_ostream.h"
+#include "llvm/Support/IRBuilder.h"
using namespace llvm;
using namespace llvm::PatternMatch;
namespace {
- class VISIBILITY_HIDDEN CodeGenPrepare : public FunctionPass {
+ class CodeGenPrepare : public FunctionPass {
/// TLI - Keep a pointer of a TargetLowering to consult for determining
/// transformation profitability.
const TargetLowering *TLI;
+ ProfileInfo *PFI;
+
+ /// BackEdges - Keep a set of all the loop back edges.
+ ///
+ SmallSet<std::pair<const BasicBlock*, const BasicBlock*>, 8> BackEdges;
public:
static char ID; // Pass identification, replacement for typeid
explicit CodeGenPrepare(const TargetLowering *tli = 0)
- : FunctionPass(&ID), TLI(tli) {}
+ : FunctionPass(ID), TLI(tli) {}
bool runOnFunction(Function &F);
+ virtual void getAnalysisUsage(AnalysisUsage &AU) const {
+ AU.addPreserved<ProfileInfo>();
+ }
+
+ virtual void releaseMemory() {
+ BackEdges.clear();
+ }
+
private:
bool EliminateMostlyEmptyBlocks(Function &F);
bool CanMergeBlocks(const BasicBlock *BB, const BasicBlock *DestBB) const;
void EliminateMostlyEmptyBlock(BasicBlock *BB);
bool OptimizeBlock(BasicBlock &BB);
- bool OptimizeLoadStoreInst(Instruction *I, Value *Addr,
- const Type *AccessTy,
- DenseMap<Value*,Value*> &SunkAddrs);
+ bool OptimizeMemoryInst(Instruction *I, Value *Addr, const Type *AccessTy,
+ DenseMap<Value*,Value*> &SunkAddrs);
bool OptimizeInlineAsmInst(Instruction *I, CallSite CS,
DenseMap<Value*,Value*> &SunkAddrs);
+ bool OptimizeCallInst(CallInst *CI);
+ bool MoveExtToFormExtLoad(Instruction *I);
bool OptimizeExtUses(Instruction *I);
+ void findLoopBackEdges(const Function &F);
};
}
char CodeGenPrepare::ID = 0;
-static RegisterPass<CodeGenPrepare> X("codegenprepare",
- "Optimize for code generation");
+INITIALIZE_PASS(CodeGenPrepare, "codegenprepare",
+ "Optimize for code generation", false, false);
FunctionPass *llvm::createCodeGenPreparePass(const TargetLowering *TLI) {
return new CodeGenPrepare(TLI);
}
+/// findLoopBackEdges - Do a DFS walk to find loop back edges.
+///
+void CodeGenPrepare::findLoopBackEdges(const Function &F) {
+ SmallVector<std::pair<const BasicBlock*,const BasicBlock*>, 32> Edges;
+ FindFunctionBackedges(F, Edges);
+
+ BackEdges.insert(Edges.begin(), Edges.end());
+}
+
bool CodeGenPrepare::runOnFunction(Function &F) {
bool EverMadeChange = false;
+ PFI = getAnalysisIfAvailable<ProfileInfo>();
// First pass, eliminate blocks that contain only PHI nodes and an
// unconditional branch.
EverMadeChange |= EliminateMostlyEmptyBlocks(F);
+ // Now find loop back edges.
+ findLoopBackEdges(F);
+
bool MadeChange = true;
while (MadeChange) {
MadeChange = false;
return EverMadeChange;
}
-/// EliminateMostlyEmptyBlocks - eliminate blocks that contain only PHI nodes
-/// and an unconditional branch. Passes before isel (e.g. LSR/loopsimplify)
-/// often split edges in ways that are non-optimal for isel. Start by
-/// eliminating these blocks so we can split them the way we want them.
+/// EliminateMostlyEmptyBlocks - eliminate blocks that contain only PHI nodes,
+/// debug info directives, and an unconditional branch. Passes before isel
+/// (e.g. LSR/loopsimplify) often split edges in ways that are non-optimal for
+/// isel. Start by eliminating these blocks so we can split them the way we
+/// want them.
bool CodeGenPrepare::EliminateMostlyEmptyBlocks(Function &F) {
bool MadeChange = false;
// Note that this intentionally skips the entry block.
if (!BI || !BI->isUnconditional())
continue;
- // If the instruction before the branch isn't a phi node, then other stuff
- // is happening here.
+ // If the instruction before the branch (skipping debug info) isn't a phi
+ // node, then other stuff is happening here.
BasicBlock::iterator BBI = BI;
if (BBI != BB->begin()) {
--BBI;
- if (!isa<PHINode>(BBI)) continue;
+ while (isa<DbgInfoIntrinsic>(BBI)) {
+ if (BBI == BB->begin())
+ break;
+ --BBI;
+ }
+ if (!isa<DbgInfoIntrinsic>(BBI) && !isa<PHINode>(BBI))
+ continue;
}
// Do not break infinite loops.
// don't mess around with them.
BasicBlock::const_iterator BBI = BB->begin();
while (const PHINode *PN = dyn_cast<PHINode>(BBI++)) {
- for (Value::use_const_iterator UI = PN->use_begin(), E = PN->use_end();
+ for (Value::const_use_iterator UI = PN->use_begin(), E = PN->use_end();
UI != E; ++UI) {
const Instruction *User = cast<Instruction>(*UI);
if (User->getParent() != DestBB || !isa<PHINode>(User))
BranchInst *BI = cast<BranchInst>(BB->getTerminator());
BasicBlock *DestBB = BI->getSuccessor(0);
- DOUT << "MERGING MOSTLY EMPTY BLOCKS - BEFORE:\n" << *BB << *DestBB;
+ DEBUG(dbgs() << "MERGING MOSTLY EMPTY BLOCKS - BEFORE:\n" << *BB << *DestBB);
// If the destination block has a single pred, then this is a trivial edge,
// just collapse it.
- if (DestBB->getSinglePredecessor()) {
- // If DestBB has single-entry PHI nodes, fold them.
- while (PHINode *PN = dyn_cast<PHINode>(DestBB->begin())) {
- Value *NewVal = PN->getIncomingValue(0);
- // Replace self referencing PHI with undef, it must be dead.
- if (NewVal == PN) NewVal = UndefValue::get(PN->getType());
- PN->replaceAllUsesWith(NewVal);
- PN->eraseFromParent();
+ if (BasicBlock *SinglePred = DestBB->getSinglePredecessor()) {
+ if (SinglePred != DestBB) {
+ // Remember if SinglePred was the entry block of the function. If so, we
+ // will need to move BB back to the entry position.
+ bool isEntry = SinglePred == &SinglePred->getParent()->getEntryBlock();
+ MergeBasicBlockIntoOnlyPred(DestBB, this);
+
+ if (isEntry && BB != &BB->getParent()->getEntryBlock())
+ BB->moveBefore(&BB->getParent()->getEntryBlock());
+
+ DEBUG(dbgs() << "AFTER:\n" << *DestBB << "\n\n\n");
+ return;
}
-
- // Splice all the PHI nodes from BB over to DestBB.
- DestBB->getInstList().splice(DestBB->begin(), BB->getInstList(),
- BB->begin(), BI);
-
- // Anything that branched to BB now branches to DestBB.
- BB->replaceAllUsesWith(DestBB);
-
- // Nuke BB.
- BB->eraseFromParent();
-
- DOUT << "AFTER:\n" << *DestBB << "\n\n\n";
- return;
}
// Otherwise, we have multiple predecessors of BB. Update the PHIs in DestBB
// The PHIs are now updated, change everything that refers to BB to use
// DestBB and remove BB.
BB->replaceAllUsesWith(DestBB);
+ if (PFI) {
+ PFI->replaceAllUses(BB, DestBB);
+ PFI->removeEdge(ProfileInfo::getEdge(BB, DestBB));
+ }
BB->eraseFromParent();
- DOUT << "AFTER:\n" << *DestBB << "\n\n\n";
+ DEBUG(dbgs() << "AFTER:\n" << *DestBB << "\n\n\n");
}
-
-/// SplitEdgeNicely - Split the critical edge from TI to its specified
-/// successor if it will improve codegen. We only do this if the successor has
-/// phi nodes (otherwise critical edges are ok). If there is already another
-/// predecessor of the succ that is empty (and thus has no phi nodes), use it
-/// instead of introducing a new block.
-static void SplitEdgeNicely(TerminatorInst *TI, unsigned SuccNum, Pass *P) {
- BasicBlock *TIBB = TI->getParent();
- BasicBlock *Dest = TI->getSuccessor(SuccNum);
- assert(isa<PHINode>(Dest->begin()) &&
- "This should only be called if Dest has a PHI!");
-
- // As a hack, never split backedges of loops. Even though the copy for any
- // PHIs inserted on the backedge would be dead for exits from the loop, we
- // assume that the cost of *splitting* the backedge would be too high.
- if (Dest == TIBB)
- return;
-
+/// FindReusablePredBB - Check all of the predecessors of the block DestPHI
+/// lives in to see if there is a block that we can reuse as a critical edge
+/// from TIBB.
+static BasicBlock *FindReusablePredBB(PHINode *DestPHI, BasicBlock *TIBB) {
+ BasicBlock *Dest = DestPHI->getParent();
+
/// TIPHIValues - This array is lazily computed to determine the values of
/// PHIs in Dest that TI would provide.
SmallVector<Value*, 32> TIPHIValues;
-
+
+ /// TIBBEntryNo - This is a cache to speed up pred queries for TIBB.
+ unsigned TIBBEntryNo = 0;
+
// Check to see if Dest has any blocks that can be used as a split edge for
// this terminator.
- for (pred_iterator PI = pred_begin(Dest), E = pred_end(Dest); PI != E; ++PI) {
- BasicBlock *Pred = *PI;
+ for (unsigned pi = 0, e = DestPHI->getNumIncomingValues(); pi != e; ++pi) {
+ BasicBlock *Pred = DestPHI->getIncomingBlock(pi);
// To be usable, the pred has to end with an uncond branch to the dest.
BranchInst *PredBr = dyn_cast<BranchInst>(Pred->getTerminator());
- if (!PredBr || !PredBr->isUnconditional() ||
- // Must be empty other than the branch.
- &Pred->front() != PredBr ||
- // Cannot be the entry block; its label does not get emitted.
- Pred == &(Dest->getParent()->getEntryBlock()))
+ if (!PredBr || !PredBr->isUnconditional())
continue;
-
+ // Must be empty other than the branch and debug info.
+ BasicBlock::iterator I = Pred->begin();
+ while (isa<DbgInfoIntrinsic>(I))
+ I++;
+ if (&*I != PredBr)
+ continue;
+ // Cannot be the entry block; its label does not get emitted.
+ if (Pred == &Dest->getParent()->getEntryBlock())
+ continue;
+
// Finally, since we know that Dest has phi nodes in it, we have to make
- // sure that jumping to Pred will have the same affect as going to Dest in
+ // sure that jumping to Pred will have the same effect as going to Dest in
// terms of PHI values.
PHINode *PN;
unsigned PHINo = 0;
+ unsigned PredEntryNo = pi;
+
bool FoundMatch = true;
for (BasicBlock::iterator I = Dest->begin();
(PN = dyn_cast<PHINode>(I)); ++I, ++PHINo) {
- if (PHINo == TIPHIValues.size())
- TIPHIValues.push_back(PN->getIncomingValueForBlock(TIBB));
-
+ if (PHINo == TIPHIValues.size()) {
+ if (PN->getIncomingBlock(TIBBEntryNo) != TIBB)
+ TIBBEntryNo = PN->getBasicBlockIndex(TIBB);
+ TIPHIValues.push_back(PN->getIncomingValue(TIBBEntryNo));
+ }
+
// If the PHI entry doesn't work, we can't use this pred.
- if (TIPHIValues[PHINo] != PN->getIncomingValueForBlock(Pred)) {
+ if (PN->getIncomingBlock(PredEntryNo) != Pred)
+ PredEntryNo = PN->getBasicBlockIndex(Pred);
+
+ if (TIPHIValues[PHINo] != PN->getIncomingValue(PredEntryNo)) {
FoundMatch = false;
break;
}
}
-
+
// If we found a workable predecessor, change TI to branch to Succ.
- if (FoundMatch) {
- Dest->removePredecessor(TIBB);
- TI->setSuccessor(SuccNum, Pred);
+ if (FoundMatch)
+ return Pred;
+ }
+ return 0;
+}
+
+
+/// SplitEdgeNicely - Split the critical edge from TI to its specified
+/// successor if it will improve codegen. We only do this if the successor has
+/// phi nodes (otherwise critical edges are ok). If there is already another
+/// predecessor of the succ that is empty (and thus has no phi nodes), use it
+/// instead of introducing a new block.
+static void SplitEdgeNicely(TerminatorInst *TI, unsigned SuccNum,
+ SmallSet<std::pair<const BasicBlock*,
+ const BasicBlock*>, 8> &BackEdges,
+ Pass *P) {
+ BasicBlock *TIBB = TI->getParent();
+ BasicBlock *Dest = TI->getSuccessor(SuccNum);
+ assert(isa<PHINode>(Dest->begin()) &&
+ "This should only be called if Dest has a PHI!");
+ PHINode *DestPHI = cast<PHINode>(Dest->begin());
+
+ // Do not split edges to EH landing pads.
+ if (InvokeInst *Invoke = dyn_cast<InvokeInst>(TI))
+ if (Invoke->getSuccessor(1) == Dest)
return;
- }
+
+ // As a hack, never split backedges of loops. Even though the copy for any
+ // PHIs inserted on the backedge would be dead for exits from the loop, we
+ // assume that the cost of *splitting* the backedge would be too high.
+ if (BackEdges.count(std::make_pair(TIBB, Dest)))
+ return;
+
+ if (BasicBlock *ReuseBB = FindReusablePredBB(DestPHI, TIBB)) {
+ ProfileInfo *PFI = P->getAnalysisIfAvailable<ProfileInfo>();
+ if (PFI)
+ PFI->splitEdge(TIBB, Dest, ReuseBB);
+ Dest->removePredecessor(TIBB);
+ TI->setSuccessor(SuccNum, ReuseBB);
+ return;
}
SplitCriticalEdge(TI, SuccNum, P, true);
}
+
/// OptimizeNoopCopyExpression - If the specified cast instruction is a noop
-/// copy (e.g. it's casting from one pointer type to another, int->uint, or
-/// int->sbyte on PPC), sink it into user blocks to reduce the number of virtual
+/// copy (e.g. it's casting from one pointer type to another, i32->i8 on PPC),
+/// sink it into user blocks to reduce the number of virtual
/// registers that must be created and coalesced.
///
/// Return true if any changes are made.
///
static bool OptimizeNoopCopyExpression(CastInst *CI, const TargetLowering &TLI){
// If this is a noop copy,
- MVT SrcVT = TLI.getValueType(CI->getOperand(0)->getType());
- MVT DstVT = TLI.getValueType(CI->getType());
+ EVT SrcVT = TLI.getValueType(CI->getOperand(0)->getType());
+ EVT DstVT = TLI.getValueType(CI->getType());
// This is an fp<->int conversion?
if (SrcVT.isInteger() != DstVT.isInteger())
// If these values will be promoted, find out what they will be promoted
// to. This helps us consider truncates on PPC as noop copies when they
// are.
- if (TLI.getTypeAction(SrcVT) == TargetLowering::Promote)
- SrcVT = TLI.getTypeToTransformTo(SrcVT);
- if (TLI.getTypeAction(DstVT) == TargetLowering::Promote)
- DstVT = TLI.getTypeToTransformTo(DstVT);
+ if (TLI.getTypeAction(CI->getContext(), SrcVT) == TargetLowering::Promote)
+ SrcVT = TLI.getTypeToTransformTo(CI->getContext(), SrcVT);
+ if (TLI.getTypeAction(CI->getContext(), DstVT) == TargetLowering::Promote)
+ DstVT = TLI.getTypeToTransformTo(CI->getContext(), DstVT);
// If, after promotion, these are the same types, this is a noop copy.
if (SrcVT != DstVT)
// appropriate predecessor block.
BasicBlock *UserBB = User->getParent();
if (PHINode *PN = dyn_cast<PHINode>(User)) {
- unsigned OpVal = UI.getOperandNo()/2;
- UserBB = PN->getIncomingBlock(OpVal);
+ UserBB = PN->getIncomingBlock(UI);
}
// Preincrement use iterator so we don't invalidate it.
BasicBlock::iterator InsertPt = UserBB->getFirstNonPHI();
InsertedCmp =
- CmpInst::Create(CI->getOpcode(), CI->getPredicate(), CI->getOperand(0),
+ CmpInst::Create(CI->getOpcode(),
+ CI->getPredicate(), CI->getOperand(0),
CI->getOperand(1), "", InsertPt);
MadeChange = true;
}
return MadeChange;
}
-/// EraseDeadInstructions - Erase any dead instructions, recursively.
-static void EraseDeadInstructions(Value *V) {
- Instruction *I = dyn_cast<Instruction>(V);
- if (!I || !I->use_empty()) return;
-
- SmallPtrSet<Instruction*, 16> Insts;
- Insts.insert(I);
-
- while (!Insts.empty()) {
- I = *Insts.begin();
- Insts.erase(I);
- if (isInstructionTriviallyDead(I)) {
- for (unsigned i = 0, e = I->getNumOperands(); i != e; ++i)
- if (Instruction *U = dyn_cast<Instruction>(I->getOperand(i)))
- Insts.insert(U);
- I->eraseFromParent();
- }
- }
-}
-
namespace {
- /// ExtAddrMode - This is an extended version of TargetLowering::AddrMode
- /// which holds actual Value*'s for register values.
- struct ExtAddrMode : public TargetLowering::AddrMode {
- Value *BaseReg;
- Value *ScaledReg;
- ExtAddrMode() : BaseReg(0), ScaledReg(0) {}
- void print(OStream &OS) const;
- void dump() const {
- print(cerr);
- cerr << '\n';
- }
- };
-} // end anonymous namespace
-
-static OStream &operator<<(OStream &OS, const ExtAddrMode &AM) {
- AM.print(OS);
- return OS;
-}
-
-
-void ExtAddrMode::print(OStream &OS) const {
- bool NeedPlus = false;
- OS << "[";
- if (BaseGV)
- OS << (NeedPlus ? " + " : "")
- << "GV:%" << BaseGV->getName(), NeedPlus = true;
-
- if (BaseOffs)
- OS << (NeedPlus ? " + " : "") << BaseOffs, NeedPlus = true;
-
- if (BaseReg)
- OS << (NeedPlus ? " + " : "")
- << "Base:%" << BaseReg->getName(), NeedPlus = true;
- if (Scale)
- OS << (NeedPlus ? " + " : "")
- << Scale << "*%" << ScaledReg->getName(), NeedPlus = true;
-
- OS << ']';
-}
-
-/// TryMatchingScaledValue - Try adding ScaleReg*Scale to the specified
-/// addressing mode. Return true if this addr mode is legal for the target,
-/// false if not.
-static bool TryMatchingScaledValue(Value *ScaleReg, int64_t Scale,
- const Type *AccessTy, ExtAddrMode &AddrMode,
- SmallVector<Instruction*, 16> &AddrModeInsts,
- const TargetLowering &TLI, unsigned Depth) {
- // If we already have a scale of this value, we can add to it, otherwise, we
- // need an available scale field.
- if (AddrMode.Scale != 0 && AddrMode.ScaledReg != ScaleReg)
- return false;
-
- ExtAddrMode TestAddrMode = AddrMode;
-
- // Add scale to turn X*4+X*3 -> X*7. This could also do things like
- // [A+B + A*7] -> [B+A*8].
- TestAddrMode.Scale += Scale;
- TestAddrMode.ScaledReg = ScaleReg;
-
- // If the new address isn't legal, bail out.
- if (!TLI.isLegalAddressingMode(TestAddrMode, AccessTy))
+class CodeGenPrepareFortifiedLibCalls : public SimplifyFortifiedLibCalls {
+protected:
+ void replaceCall(Value *With) {
+ CI->replaceAllUsesWith(With);
+ CI->eraseFromParent();
+ }
+ bool isFoldable(unsigned SizeCIOp, unsigned, bool) const {
+ if (ConstantInt *SizeCI =
+ dyn_cast<ConstantInt>(CI->getArgOperand(SizeCIOp)))
+ return SizeCI->isAllOnesValue();
return false;
-
- // It was legal, so commit it.
- AddrMode = TestAddrMode;
-
- // Okay, we decided that we can add ScaleReg+Scale to AddrMode. Check now
- // to see if ScaleReg is actually X+C. If so, we can turn this into adding
- // X*Scale + C*Scale to addr mode.
- ConstantInt *CI; Value *AddLHS;
- if (match(ScaleReg, m_Add(m_Value(AddLHS), m_ConstantInt(CI)))) {
- TestAddrMode.ScaledReg = AddLHS;
- TestAddrMode.BaseOffs += CI->getSExtValue()*TestAddrMode.Scale;
-
- // If this addressing mode is legal, commit it and remember that we folded
- // this instruction.
- if (TLI.isLegalAddressingMode(TestAddrMode, AccessTy)) {
- AddrModeInsts.push_back(cast<Instruction>(ScaleReg));
- AddrMode = TestAddrMode;
- }
}
+};
+} // end anonymous namespace
- // Otherwise, not (x+c)*scale, just return what we have.
- return true;
-}
-
-
-/// FindMaximalLegalAddressingMode - If we can, try to merge the computation of
-/// Addr into the specified addressing mode. If Addr can't be added to AddrMode
-/// this returns false. This assumes that Addr is either a pointer type or
-/// intptr_t for the target.
-///
-/// This method is used to optimize both load/store and inline asms with memory
-/// operands.
-static bool FindMaximalLegalAddressingMode(Value *Addr, const Type *AccessTy,
- ExtAddrMode &AddrMode,
- SmallVectorImpl<Instruction*> &AddrModeInsts,
- const TargetLowering &TLI,
- unsigned Depth) {
-
- // If this is a global variable, fold it into the addressing mode if possible.
- if (GlobalValue *GV = dyn_cast<GlobalValue>(Addr)) {
- if (AddrMode.BaseGV == 0) {
- AddrMode.BaseGV = GV;
- if (TLI.isLegalAddressingMode(AddrMode, AccessTy))
- return true;
- AddrMode.BaseGV = 0;
- }
- } else if (ConstantInt *CI = dyn_cast<ConstantInt>(Addr)) {
- AddrMode.BaseOffs += CI->getSExtValue();
- if (TLI.isLegalAddressingMode(AddrMode, AccessTy))
- return true;
- AddrMode.BaseOffs -= CI->getSExtValue();
- } else if (isa<ConstantPointerNull>(Addr)) {
+bool CodeGenPrepare::OptimizeCallInst(CallInst *CI) {
+ // Lower all uses of llvm.objectsize.*
+ IntrinsicInst *II = dyn_cast<IntrinsicInst>(CI);
+ if (II && II->getIntrinsicID() == Intrinsic::objectsize) {
+ bool Min = (cast<ConstantInt>(II->getArgOperand(1))->getZExtValue() == 1);
+ const Type *ReturnTy = CI->getType();
+ Constant *RetVal = ConstantInt::get(ReturnTy, Min ? 0 : -1ULL);
+ CI->replaceAllUsesWith(RetVal);
+ CI->eraseFromParent();
return true;
}
- // Look through constant exprs and instructions.
- unsigned Opcode = ~0U;
- User *AddrInst = 0;
- if (Instruction *I = dyn_cast<Instruction>(Addr)) {
- Opcode = I->getOpcode();
- AddrInst = I;
- } else if (ConstantExpr *CE = dyn_cast<ConstantExpr>(Addr)) {
- Opcode = CE->getOpcode();
- AddrInst = CE;
- }
-
- // Limit recursion to avoid exponential behavior.
- if (Depth == 5) { AddrInst = 0; Opcode = ~0U; }
-
- // If this is really an instruction, add it to our list of related
- // instructions.
- if (Instruction *I = dyn_cast_or_null<Instruction>(AddrInst))
- AddrModeInsts.push_back(I);
-
-#if 0
- if (AddrInst && !AddrInst->hasOneUse())
- ;
- else
-#endif
- switch (Opcode) {
- case Instruction::PtrToInt:
- // PtrToInt is always a noop, as we know that the int type is pointer sized.
- if (FindMaximalLegalAddressingMode(AddrInst->getOperand(0), AccessTy,
- AddrMode, AddrModeInsts, TLI, Depth))
- return true;
- break;
- case Instruction::IntToPtr:
- // This inttoptr is a no-op if the integer type is pointer sized.
- if (TLI.getValueType(AddrInst->getOperand(0)->getType()) ==
- TLI.getPointerTy()) {
- if (FindMaximalLegalAddressingMode(AddrInst->getOperand(0), AccessTy,
- AddrMode, AddrModeInsts, TLI, Depth))
- return true;
- }
- break;
- case Instruction::Add: {
- // Check to see if we can merge in the RHS then the LHS. If so, we win.
- ExtAddrMode BackupAddrMode = AddrMode;
- unsigned OldSize = AddrModeInsts.size();
- if (FindMaximalLegalAddressingMode(AddrInst->getOperand(1), AccessTy,
- AddrMode, AddrModeInsts, TLI, Depth+1) &&
- FindMaximalLegalAddressingMode(AddrInst->getOperand(0), AccessTy,
- AddrMode, AddrModeInsts, TLI, Depth+1))
- return true;
-
- // Restore the old addr mode info.
- AddrMode = BackupAddrMode;
- AddrModeInsts.resize(OldSize);
-
- // Otherwise this was over-aggressive. Try merging in the LHS then the RHS.
- if (FindMaximalLegalAddressingMode(AddrInst->getOperand(0), AccessTy,
- AddrMode, AddrModeInsts, TLI, Depth+1) &&
- FindMaximalLegalAddressingMode(AddrInst->getOperand(1), AccessTy,
- AddrMode, AddrModeInsts, TLI, Depth+1))
- return true;
-
- // Otherwise we definitely can't merge the ADD in.
- AddrMode = BackupAddrMode;
- AddrModeInsts.resize(OldSize);
- break;
- }
- case Instruction::Or: {
- //ConstantInt *RHS = dyn_cast<ConstantInt>(AddrInst->getOperand(1));
- //if (!RHS) break;
- // TODO: We can handle "Or Val, Imm" iff this OR is equivalent to an ADD.
- break;
- }
- case Instruction::Mul:
- case Instruction::Shl: {
- // Can only handle X*C and X << C, and can only handle this when the scale
- // field is available.
- ConstantInt *RHS = dyn_cast<ConstantInt>(AddrInst->getOperand(1));
- if (!RHS) break;
- int64_t Scale = RHS->getSExtValue();
- if (Opcode == Instruction::Shl)
- Scale = 1 << Scale;
-
- if (TryMatchingScaledValue(AddrInst->getOperand(0), Scale, AccessTy,
- AddrMode, AddrModeInsts, TLI, Depth))
- return true;
- break;
- }
- case Instruction::GetElementPtr: {
- // Scan the GEP. We check it if it contains constant offsets and at most
- // one variable offset.
- int VariableOperand = -1;
- unsigned VariableScale = 0;
-
- int64_t ConstantOffset = 0;
- const TargetData *TD = TLI.getTargetData();
- gep_type_iterator GTI = gep_type_begin(AddrInst);
- for (unsigned i = 1, e = AddrInst->getNumOperands(); i != e; ++i, ++GTI) {
- if (const StructType *STy = dyn_cast<StructType>(*GTI)) {
- const StructLayout *SL = TD->getStructLayout(STy);
- unsigned Idx =
- cast<ConstantInt>(AddrInst->getOperand(i))->getZExtValue();
- ConstantOffset += SL->getElementOffset(Idx);
- } else {
- uint64_t TypeSize = TD->getABITypeSize(GTI.getIndexedType());
- if (ConstantInt *CI = dyn_cast<ConstantInt>(AddrInst->getOperand(i))) {
- ConstantOffset += CI->getSExtValue()*TypeSize;
- } else if (TypeSize) { // Scales of zero don't do anything.
- // We only allow one variable index at the moment.
- if (VariableOperand != -1) {
- VariableOperand = -2;
- break;
- }
-
- // Remember the variable index.
- VariableOperand = i;
- VariableScale = TypeSize;
- }
- }
- }
-
- // If the GEP had multiple variable indices, punt.
- if (VariableOperand == -2)
- break;
-
- // A common case is for the GEP to only do a constant offset. In this case,
- // just add it to the disp field and check validity.
- if (VariableOperand == -1) {
- AddrMode.BaseOffs += ConstantOffset;
- if (ConstantOffset == 0 || TLI.isLegalAddressingMode(AddrMode, AccessTy)){
- // Check to see if we can fold the base pointer in too.
- if (FindMaximalLegalAddressingMode(AddrInst->getOperand(0), AccessTy,
- AddrMode, AddrModeInsts, TLI,
- Depth+1))
- return true;
- }
- AddrMode.BaseOffs -= ConstantOffset;
- } else {
- // Check that this has no base reg yet. If so, we won't have a place to
- // put the base of the GEP (assuming it is not a null ptr).
- bool SetBaseReg = false;
- if (AddrMode.HasBaseReg) {
- if (!isa<ConstantPointerNull>(AddrInst->getOperand(0)))
- break;
- } else {
- AddrMode.HasBaseReg = true;
- AddrMode.BaseReg = AddrInst->getOperand(0);
- SetBaseReg = true;
- }
-
- // See if the scale amount is valid for this target.
- AddrMode.BaseOffs += ConstantOffset;
- if (TryMatchingScaledValue(AddrInst->getOperand(VariableOperand),
- VariableScale, AccessTy, AddrMode,
- AddrModeInsts, TLI, Depth)) {
- if (!SetBaseReg) return true;
-
- // If this match succeeded, we know that we can form an address with the
- // GepBase as the basereg. See if we can match *more*.
- AddrMode.HasBaseReg = false;
- AddrMode.BaseReg = 0;
- if (FindMaximalLegalAddressingMode(AddrInst->getOperand(0), AccessTy,
- AddrMode, AddrModeInsts, TLI,
- Depth+1))
- return true;
- // Strange, shouldn't happen. Restore the base reg and succeed the easy
- // way.
- AddrMode.HasBaseReg = true;
- AddrMode.BaseReg = AddrInst->getOperand(0);
- return true;
- }
-
- AddrMode.BaseOffs -= ConstantOffset;
- if (SetBaseReg) {
- AddrMode.HasBaseReg = false;
- AddrMode.BaseReg = 0;
- }
- }
- break;
- }
- }
-
- if (Instruction *I = dyn_cast_or_null<Instruction>(AddrInst)) {
- assert(AddrModeInsts.back() == I && "Stack imbalance"); I = I;
- AddrModeInsts.pop_back();
- }
-
- // Worse case, the target should support [reg] addressing modes. :)
- if (!AddrMode.HasBaseReg) {
- AddrMode.HasBaseReg = true;
- // Still check for legality in case the target supports [imm] but not [i+r].
- if (TLI.isLegalAddressingMode(AddrMode, AccessTy)) {
- AddrMode.BaseReg = Addr;
- return true;
- }
- AddrMode.HasBaseReg = false;
- }
-
- // If the base register is already taken, see if we can do [r+r].
- if (AddrMode.Scale == 0) {
- AddrMode.Scale = 1;
- if (TLI.isLegalAddressingMode(AddrMode, AccessTy)) {
- AddrMode.ScaledReg = Addr;
- return true;
- }
- AddrMode.Scale = 0;
- }
- // Couldn't match.
- return false;
+ // From here on out we're working with named functions.
+ if (CI->getCalledFunction() == 0) return false;
+
+ // We'll need TargetData from here on out.
+ const TargetData *TD = TLI ? TLI->getTargetData() : 0;
+ if (!TD) return false;
+
+ // Lower all default uses of _chk calls. This is very similar
+ // to what InstCombineCalls does, but here we are only lowering calls
+ // that have the default "don't know" as the objectsize. Anything else
+ // should be left alone.
+ CodeGenPrepareFortifiedLibCalls Simplifier;
+ return Simplifier.fold(CI, TD);
}
-
+//===----------------------------------------------------------------------===//
+// Memory Optimization
+//===----------------------------------------------------------------------===//
/// IsNonLocalValue - Return true if the specified values are defined in a
/// different basic block than BB.
return false;
}
-/// OptimizeLoadStoreInst - Load and Store Instructions have often have
+/// OptimizeMemoryInst - Load and Store Instructions often have
/// addressing modes that can do significant amounts of computation. As such,
/// instruction selection will try to get the load or store to do as much
/// computation as possible for the program. The problem is that isel can only
/// see within a single block. As such, we sink as much legal addressing mode
/// stuff into the block as possible.
-bool CodeGenPrepare::OptimizeLoadStoreInst(Instruction *LdStInst, Value *Addr,
- const Type *AccessTy,
- DenseMap<Value*,Value*> &SunkAddrs) {
+///
+/// This method is used to optimize both load/store and inline asms with memory
+/// operands.
+bool CodeGenPrepare::OptimizeMemoryInst(Instruction *MemoryInst, Value *Addr,
+ const Type *AccessTy,
+ DenseMap<Value*,Value*> &SunkAddrs) {
// Figure out what addressing mode will be built up for this operation.
SmallVector<Instruction*, 16> AddrModeInsts;
- ExtAddrMode AddrMode;
- bool Success = FindMaximalLegalAddressingMode(Addr, AccessTy, AddrMode,
- AddrModeInsts, *TLI, 0);
- Success = Success; assert(Success && "Couldn't select *anything*?");
+ ExtAddrMode AddrMode = AddressingModeMatcher::Match(Addr, AccessTy,MemoryInst,
+ AddrModeInsts, *TLI);
// Check to see if any of the instructions supersumed by this addr mode are
// non-local to I's BB.
bool AnyNonLocal = false;
for (unsigned i = 0, e = AddrModeInsts.size(); i != e; ++i) {
- if (IsNonLocalValue(AddrModeInsts[i], LdStInst->getParent())) {
+ if (IsNonLocalValue(AddrModeInsts[i], MemoryInst->getParent())) {
AnyNonLocal = true;
break;
}
// If all the instructions matched are already in this BB, don't do anything.
if (!AnyNonLocal) {
- DEBUG(cerr << "CGP: Found local addrmode: " << AddrMode << "\n");
+ DEBUG(dbgs() << "CGP: Found local addrmode: " << AddrMode << "\n");
return false;
}
// Insert this computation right after this user. Since our caller is
// scanning from the top of the BB to the bottom, reuse of the expr are
// guaranteed to happen later.
- BasicBlock::iterator InsertPt = LdStInst;
+ BasicBlock::iterator InsertPt = MemoryInst;
// Now that we determined the addressing expression we want to use and know
// that we have to sink it into this block. Check to see if we have already
// computation.
Value *&SunkAddr = SunkAddrs[Addr];
if (SunkAddr) {
- DEBUG(cerr << "CGP: Reusing nonlocal addrmode: " << AddrMode << "\n");
+ DEBUG(dbgs() << "CGP: Reusing nonlocal addrmode: " << AddrMode << " for "
+ << *MemoryInst);
if (SunkAddr->getType() != Addr->getType())
SunkAddr = new BitCastInst(SunkAddr, Addr->getType(), "tmp", InsertPt);
} else {
- DEBUG(cerr << "CGP: SINKING nonlocal addrmode: " << AddrMode << "\n");
- const Type *IntPtrTy = TLI->getTargetData()->getIntPtrType();
+ DEBUG(dbgs() << "CGP: SINKING nonlocal addrmode: " << AddrMode << " for "
+ << *MemoryInst);
+ const Type *IntPtrTy =
+ TLI->getTargetData()->getIntPtrType(AccessTy->getContext());
Value *Result = 0;
- // Start with the scale value.
+
+ // Start with the base register. Do this first so that subsequent address
+ // matching finds it last, which will prevent it from trying to match it
+ // as the scaled value in case it happens to be a mul. That would be
+ // problematic if we've sunk a different mul for the scale, because then
+ // we'd end up sinking both muls.
+ if (AddrMode.BaseReg) {
+ Value *V = AddrMode.BaseReg;
+ if (V->getType()->isPointerTy())
+ V = new PtrToIntInst(V, IntPtrTy, "sunkaddr", InsertPt);
+ if (V->getType() != IntPtrTy)
+ V = CastInst::CreateIntegerCast(V, IntPtrTy, /*isSigned=*/true,
+ "sunkaddr", InsertPt);
+ Result = V;
+ }
+
+ // Add the scale value.
if (AddrMode.Scale) {
Value *V = AddrMode.ScaledReg;
if (V->getType() == IntPtrTy) {
// done.
- } else if (isa<PointerType>(V->getType())) {
+ } else if (V->getType()->isPointerTy()) {
V = new PtrToIntInst(V, IntPtrTy, "sunkaddr", InsertPt);
} else if (cast<IntegerType>(IntPtrTy)->getBitWidth() <
cast<IntegerType>(V->getType())->getBitWidth()) {
}
if (AddrMode.Scale != 1)
V = BinaryOperator::CreateMul(V, ConstantInt::get(IntPtrTy,
- AddrMode.Scale),
+ AddrMode.Scale),
"sunkaddr", InsertPt);
- Result = V;
- }
-
- // Add in the base register.
- if (AddrMode.BaseReg) {
- Value *V = AddrMode.BaseReg;
- if (V->getType() != IntPtrTy)
- V = new PtrToIntInst(V, IntPtrTy, "sunkaddr", InsertPt);
if (Result)
Result = BinaryOperator::CreateAdd(Result, V, "sunkaddr", InsertPt);
else
SunkAddr = new IntToPtrInst(Result, Addr->getType(), "sunkaddr",InsertPt);
}
- LdStInst->replaceUsesOfWith(Addr, SunkAddr);
+ MemoryInst->replaceUsesOfWith(Addr, SunkAddr);
- if (Addr->use_empty())
- EraseDeadInstructions(Addr);
+ if (Addr->use_empty()) {
+ RecursivelyDeleteTriviallyDeadInstructions(Addr);
+ // This address is now available for reassignment, so erase the table entry;
+ // we don't want to match some completely different instruction.
+ SunkAddrs[Addr] = 0;
+ }
return true;
}
/// OptimizeInlineAsmInst - If there are any memory operands, use
-/// OptimizeLoadStoreInt to sink their address computing into the block when
+/// OptimizeMemoryInst to sink their address computing into the block when
/// possible / profitable.
bool CodeGenPrepare::OptimizeInlineAsmInst(Instruction *I, CallSite CS,
DenseMap<Value*,Value*> &SunkAddrs) {
}
// Compute the constraint code and ConstraintType to use.
- TLI->ComputeConstraintToUse(OpInfo, SDValue(),
- OpInfo.ConstraintType == TargetLowering::C_Memory);
+ TLI->ComputeConstraintToUse(OpInfo, SDValue());
if (OpInfo.ConstraintType == TargetLowering::C_Memory &&
OpInfo.isIndirect) {
Value *OpVal = OpInfo.CallOperandVal;
- MadeChange |= OptimizeLoadStoreInst(I, OpVal, OpVal->getType(),
- SunkAddrs);
+ MadeChange |= OptimizeMemoryInst(I, OpVal, OpVal->getType(), SunkAddrs);
}
}
return MadeChange;
}
+/// MoveExtToFormExtLoad - Move a zext or sext fed by a load into the same
+/// basic block as the load, unless conditions are unfavorable. This allows
+/// SelectionDAG to fold the extend into the load.
+///
+bool CodeGenPrepare::MoveExtToFormExtLoad(Instruction *I) {
+ // Look for a load being extended.
+ LoadInst *LI = dyn_cast<LoadInst>(I->getOperand(0));
+ if (!LI) return false;
+
+ // If they're already in the same block, there's nothing to do.
+ if (LI->getParent() == I->getParent())
+ return false;
+
+ // If the load has other users and the truncate is not free, this probably
+ // isn't worthwhile.
+ if (!LI->hasOneUse() &&
+ TLI && !TLI->isTruncateFree(I->getType(), LI->getType()))
+ return false;
+
+ // Check whether the target supports casts folded into loads.
+ unsigned LType;
+ if (isa<ZExtInst>(I))
+ LType = ISD::ZEXTLOAD;
+ else {
+ assert(isa<SExtInst>(I) && "Unexpected ext type!");
+ LType = ISD::SEXTLOAD;
+ }
+ if (TLI && !TLI->isLoadExtLegal(LType, TLI->getValueType(LI->getType())))
+ return false;
+
+ // Move the extend into the same block as the load, so that SelectionDAG
+ // can fold it.
+ I->removeFromParent();
+ I->insertAfter(LI);
+ return true;
+}
+
bool CodeGenPrepare::OptimizeExtUses(Instruction *I) {
BasicBlock *DefBB = I->getParent();
bool CodeGenPrepare::OptimizeBlock(BasicBlock &BB) {
bool MadeChange = false;
- // Split all critical edges where the dest block has a PHI and where the phi
- // has shared immediate operands.
+ // Split all critical edges where the dest block has a PHI.
TerminatorInst *BBTI = BB.getTerminator();
- if (BBTI->getNumSuccessors() > 1) {
- for (unsigned i = 0, e = BBTI->getNumSuccessors(); i != e; ++i)
- if (isa<PHINode>(BBTI->getSuccessor(i)->begin()) &&
- isCriticalEdge(BBTI, i, true))
- SplitEdgeNicely(BBTI, i, this);
+ if (BBTI->getNumSuccessors() > 1 && !isa<IndirectBrInst>(BBTI)) {
+ for (unsigned i = 0, e = BBTI->getNumSuccessors(); i != e; ++i) {
+ BasicBlock *SuccBB = BBTI->getSuccessor(i);
+ if (isa<PHINode>(SuccBB->begin()) && isCriticalEdge(BBTI, i, true))
+ SplitEdgeNicely(BBTI, i, BackEdges, this);
+ }
}
-
// Keep track of non-local addresses that have been sunk into this block.
// This allows us to avoid inserting duplicate code for blocks with multiple
// load/stores of the same address.
MadeChange |= Change;
}
- if (!Change && (isa<ZExtInst>(I) || isa<SExtInst>(I)))
+ if (!Change && (isa<ZExtInst>(I) || isa<SExtInst>(I))) {
+ MadeChange |= MoveExtToFormExtLoad(I);
MadeChange |= OptimizeExtUses(I);
+ }
} else if (CmpInst *CI = dyn_cast<CmpInst>(I)) {
MadeChange |= OptimizeCmpExpression(CI);
} else if (LoadInst *LI = dyn_cast<LoadInst>(I)) {
if (TLI)
- MadeChange |= OptimizeLoadStoreInst(I, I->getOperand(0), LI->getType(),
- SunkAddrs);
+ MadeChange |= OptimizeMemoryInst(I, I->getOperand(0), LI->getType(),
+ SunkAddrs);
} else if (StoreInst *SI = dyn_cast<StoreInst>(I)) {
if (TLI)
- MadeChange |= OptimizeLoadStoreInst(I, SI->getOperand(1),
- SI->getOperand(0)->getType(),
- SunkAddrs);
+ MadeChange |= OptimizeMemoryInst(I, SI->getOperand(1),
+ SI->getOperand(0)->getType(),
+ SunkAddrs);
} else if (GetElementPtrInst *GEPI = dyn_cast<GetElementPtrInst>(I)) {
if (GEPI->hasAllZeroIndices()) {
/// The GEP operand must be a pointer, so must its result -> BitCast
} else if (CallInst *CI = dyn_cast<CallInst>(I)) {
// If we found an inline asm expession, and if the target knows how to
// lower it to normal LLVM code, do so now.
- if (TLI && isa<InlineAsm>(CI->getCalledValue()))
- if (const TargetAsmInfo *TAI =
- TLI->getTargetMachine().getTargetAsmInfo()) {
- if (TAI->ExpandInlineAsm(CI))
- BBI = BB.begin();
- else
- // Sink address computing for memory operands into the block.
- MadeChange |= OptimizeInlineAsmInst(I, &(*CI), SunkAddrs);
- }
+ if (TLI && isa<InlineAsm>(CI->getCalledValue())) {
+ if (TLI->ExpandInlineAsm(CI)) {
+ BBI = BB.begin();
+ // Avoid processing instructions out of order, which could cause
+ // reuse before a value is defined.
+ SunkAddrs.clear();
+ } else
+ // Sink address computing for memory operands into the block.
+ MadeChange |= OptimizeInlineAsmInst(I, &(*CI), SunkAddrs);
+ } else {
+ // Other CallInst optimizations that don't need to muck with the
+ // enclosing iterator here.
+ MadeChange |= OptimizeCallInst(CI);
+ }
}
}
projects / oota-llvm.git / blobdiff