LD.Flags += -Wl,--no-relax
endif
+ifeq ($(OS),MingW)
+ ifeq ($(LLVM_CROSS_COMPILING),1)
+ # Work around http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=525016
+ ifdef TOOLNAME
+ LD.Flags += -Wl,--allow-multiple-definition
+ endif
+ endif
+endif
+
#--------------------------------------------------------------------
# Directory locations
#--------------------------------------------------------------------
about symbols remaining in the table on destruction.</p>
<p><b>GCC 4.1.2 20071124 (Red Hat 4.1.2-42)</b>: Suffers from the same symptoms
as the previous one. It appears to work with ENABLE_OPTIMIZED=0 (the default).</p>
+<p><b>Cygwin GCC 4.3.2 20080827 (beta) 2</b>:
+ Users <a href="http://llvm.org/PR4145">reported</a> various problems related
+ with link errors when using this GCC version.</p>
<p><b>GNU ld 2.16.X</b>. Some 2.16.X versions of the ld linker will produce very
long warning messages complaining that some ".gnu.linkonce.t.*" symbol was
return true;
}
+ template <typename IterT>
+ void insert(IterT I, IterT E) {
+ for (; I != E; ++I)
+ insert(*I);
+ }
+
bool erase(const T &V) {
if (!isSmall())
return Set.erase(V);
return ID;
}
- /// RecordSourceLine - Records location information and associates it with a
- /// label. Returns a unique label ID used to generate a label and
- /// provide correspondence to the source line list.
- unsigned RecordSourceLine(unsigned Line, unsigned Column, unsigned Source);
-
/// InvalidateLabel - Inhibit use of the specified label # from
/// MachineModuleInfo, for example because the code was deleted.
void InvalidateLabel(unsigned LabelID) {
BasicBlock::iterator &ScanFrom,
unsigned MaxInstsToScan = 6,
AliasAnalysis *AA = 0);
-
+
+/// FindFunctionBackedges - Analyze the specified function to find all of the
+/// loop backedges in the function and return them. This is a relatively cheap
+/// (compared to computing dominators and loop info) analysis.
+///
+/// The output is added to Result, as pairs of <from,to> edge info.
+void FindFunctionBackedges(const Function &F,
+ SmallVectorImpl<std::pair<const BasicBlock*,const BasicBlock*> > &Result);
// RemoveSuccessor - Change the specified terminator instruction such that its
switch (I->getOpcode()) {
case Instruction::Call:
case Instruction::Invoke: {
- CallSite CS = CallSite::get(I);
- // Not captured if the callee is readonly and doesn't return a copy
- // through its return value.
- if (CS.onlyReadsMemory() && I->getType() == Type::VoidTy)
- break;
+ CallSite CS(I);
// Not captured if only passed via 'nocapture' arguments. Note that
// calling a function pointer does not in itself cause the pointer to
// that loading a value from a pointer does not cause the pointer to be
// captured, even though the loaded value might be the pointer itself
// (think of self-referential objects).
+ bool MayBeCaptured = false;
CallSite::arg_iterator B = CS.arg_begin(), E = CS.arg_end();
for (CallSite::arg_iterator A = B; A != E; ++A)
- if (A->get() == V && !CS.paramHasAttr(A - B + 1, Attribute::NoCapture))
- // The parameter is not marked 'nocapture' - captured.
- return true;
- // Only passed via 'nocapture' arguments, or is the called function - not
- // captured.
+ if (A->get() == V && !CS.paramHasAttr(A-B+1, Attribute::NoCapture)) {
+ // The parameter is not marked 'nocapture' - handled by generic code
+ // below.
+ MayBeCaptured = true;
+ break;
+ }
+ if (!MayBeCaptured)
+ // Only passed via 'nocapture' arguments, or is the called function -
+ // not captured.
+ continue;
+ if (!CS.doesNotThrow())
+ // Even a readonly function can leak bits by throwing an exception or
+ // not depending on the input value.
+ return true;
+ // Fall through to the generic code.
break;
}
case Instruction::Free:
// Freeing a pointer does not cause it to be captured.
- break;
+ continue;
case Instruction::Load:
// Loading from a pointer does not cause it to be captured.
- break;
+ continue;
case Instruction::Ret:
if (ReturnCaptures)
return true;
- break;
+ continue;
case Instruction::Store:
if (V == I->getOperand(0))
// Stored the pointer - it may be captured.
return true;
// Storing to the pointee does not cause the pointer to be captured.
- break;
- case Instruction::BitCast:
- case Instruction::GetElementPtr:
- case Instruction::PHI:
- case Instruction::Select:
- // The original value is not captured via this if the new value isn't.
- for (Instruction::use_iterator UI = I->use_begin(), UE = I->use_end();
- UI != UE; ++UI) {
- Use *U = &UI.getUse();
- if (Visited.insert(U))
- Worklist.push_back(U);
- }
- break;
- default:
- // Something else - be conservative and say it is captured.
+ continue;
+ }
+
+ // If it may write to memory and isn't one of the special cases above,
+ // be conservative and assume the pointer is captured.
+ if (I->mayWriteToMemory())
return true;
+
+ // If the instruction doesn't write memory, it can only capture by
+ // having its own value depend on the input value.
+ const Type* Ty = I->getType();
+ if (Ty == Type::VoidTy)
+ // The value of an instruction can't be a copy if it can't contain any
+ // information.
+ continue;
+ if (!isa<PointerType>(Ty))
+ // At the moment, we don't track non-pointer values, so be conservative
+ // and assume the pointer is captured.
+ // FIXME: Track these too. This would need to be done very carefully as
+ // it is easy to leak bits via control flow if integer values are allowed.
+ return true;
+
+ // The original value is not captured via this if the new value isn't.
+ for (Instruction::use_iterator UI = I->use_begin(), UE = I->use_end();
+ UI != UE; ++UI) {
+ Use *U = &UI.getUse();
+ if (Visited.insert(U))
+ Worklist.push_back(U);
}
}
// Assumes in correct section after the entry point.
EmitLabel("func_begin", ++SubprogramCount);
- // Emit label for the implicitly defined dbg.stoppoint at the start of
- // the function.
- if (!Lines.empty()) {
- const SrcLineInfo &LineInfo = Lines[0];
- Asm->printLabel(LineInfo.getLabelID());
+ DebugLoc FDL = MF->getDefaultDebugLoc();
+ if (!FDL.isUnknown()) {
+ DebugLocTuple DLT = MF->getDebugLocTuple(FDL);
+ unsigned LabelID = RecordSourceLine(DLT.Line, DLT.Col,
+ DICompileUnit(DLT.CompileUnit));
+ Asm->printLabel(LabelID);
}
if (TimePassesIsEnabled)
unsigned Col = SPI->getColumn();
unsigned Idx = MF.getOrCreateDebugLocID(CU.getGV(), Line, Col);
setCurDebugLoc(DebugLoc::get(Idx));
- if (DW && DW->ShouldEmitDwarfDebug()) {
- unsigned ID = DW->RecordSourceLine(Line, Col, CU);
- const TargetInstrDesc &II = TII.get(TargetInstrInfo::DBG_LABEL);
- BuildMI(MBB, DL, II).addImm(ID);
- }
}
return true;
}
CompileUnit.getGV(), Line, 0)));
if (DW && DW->ShouldEmitDwarfDebug()) {
- unsigned LabelID = DW->RecordSourceLine(Line, 0, CompileUnit);
+ unsigned LabelID = MMI->NextLabelID();
const TargetInstrDesc &II = TII.get(TargetInstrInfo::DBG_LABEL);
BuildMI(MBB, DL, II).addImm(LabelID);
DebugLocTuple PrevLocTpl = MF.getDebugLocTuple(PrevLoc);
} else {
// Record the source line.
unsigned Line = Subprogram.getLineNumber();
- setCurDebugLoc(DebugLoc::get(MF.getOrCreateDebugLocID(
+ MF.setDefaultDebugLoc(DebugLoc::get(MF.getOrCreateDebugLocID(
CompileUnit.getGV(), Line, 0)));
if (DW && DW->ShouldEmitDwarfDebug()) {
- DW->RecordSourceLine(Line, 0, CompileUnit);
// llvm.dbg.func_start also defines beginning of function scope.
DW->RecordRegionStart(cast<GlobalVariable>(FSI->getSubprogram()));
}
MF.getOrCreateDebugLocID(CompileUnit.getGV(), Line, 0)));
if (DW && DW->ShouldEmitDwarfDebug()) {
- unsigned LabelID = DW->RecordSourceLine(Line, 0, CompileUnit);
+ unsigned LabelID = DAG.getMachineModuleInfo()->NextLabelID();
DAG.setRoot(DAG.getLabel(ISD::DBG_LABEL, getCurDebugLoc(),
getRoot(), LabelID));
DebugLocTuple PrevLocTpl = MF.getDebugLocTuple(PrevLoc);
} else {
// Record the source line.
unsigned Line = Subprogram.getLineNumber();
- setCurDebugLoc(DebugLoc::get(
+ MF.setDefaultDebugLoc(DebugLoc::get(
MF.getOrCreateDebugLocID(CompileUnit.getGV(), Line, 0)));
if (DW && DW->ShouldEmitDwarfDebug()) {
- DW->RecordSourceLine(Line, 0, CompileUnit);
// llvm.dbg.func_start also defines beginning of function scope.
DW->RecordRegionStart(cast<GlobalVariable>(FSI.getSubprogram()));
}
int SS = li->getStackSlotIndex();
if (!UsedColors[SS])
continue;
- // Get the largest common sub- register class of all the stack slots that
- // are colored to this stack slot.
- const TargetRegisterClass *RC = 0;
- for (unsigned j = 0, ee = RevMap[SS].size(); j != ee; ++j) {
- int RSS = RevMap[SS][j];
- const TargetRegisterClass *RRC = LS->getIntervalRegClass(RSS);
- if (!RC)
- RC = RRC;
- else
- RC = getCommonSubClass(RC, RRC);
- }
- // If it's not colored to another stack slot, try coloring it
- // to a "free" register.
- if (!RC)
- continue;
- unsigned Reg = VRM->getFirstUnusedRegister(RC);
- if (!Reg)
- continue;
- bool IsSafe = true;
+ // These slots allow to share the same registers.
+ bool AllColored = true;
+ SmallVector<unsigned, 4> ColoredRegs;
for (unsigned j = 0, ee = RevMap[SS].size(); j != ee; ++j) {
int RSS = RevMap[SS][j];
+ const TargetRegisterClass *RC = LS->getIntervalRegClass(RSS);
+ // If it's not colored to another stack slot, try coloring it
+ // to a "free" register.
+ if (!RC) {
+ AllColored = false;
+ continue;
+ }
+ unsigned Reg = VRM->getFirstUnusedRegister(RC);
+ if (!Reg) {
+ AllColored = false;
+ continue;
+ }
if (!AllMemRefsCanBeUnfolded(RSS)) {
- IsSafe = false;
- break;
+ AllColored = false;
+ continue;
+ } else {
+ DOUT << "Assigning fi#" << RSS << " to " << TRI->getName(Reg) << '\n';
+ ColoredRegs.push_back(Reg);
+ SlotMapping[RSS] = Reg;
+ SlotIsReg.set(RSS);
+ Changed = true;
}
}
- if (!IsSafe)
- // Try color the next spill slot.
- continue;
- DOUT << "Assigning fi#" << SS << " to " << TRI->getName(Reg)
- << ", which in turn means...\n";
// Register and its sub-registers are no longer free.
- VRM->setRegisterUsed(Reg);
- // If reg is a callee-saved register, it will have to be spilled in
- // the prologue.
- MRI->setPhysRegUsed(Reg);
- for (const unsigned *AS = TRI->getAliasSet(Reg); *AS; ++AS) {
- VRM->setRegisterUsed(*AS);
- MRI->setPhysRegUsed(*AS);
+ while (!ColoredRegs.empty()) {
+ unsigned Reg = ColoredRegs.back();
+ ColoredRegs.pop_back();
+ VRM->setRegisterUsed(Reg);
+ // If reg is a callee-saved register, it will have to be spilled in
+ // the prologue.
+ MRI->setPhysRegUsed(Reg);
+ for (const unsigned *AS = TRI->getAliasSet(Reg); *AS; ++AS) {
+ VRM->setRegisterUsed(*AS);
+ MRI->setPhysRegUsed(*AS);
+ }
}
// This spill slot is dead after the rewrites
- MFI->RemoveStackObject(SS);
-
- // Remember all these FI references will have to be unfolded.
- for (unsigned j = 0, ee = RevMap[SS].size(); j != ee; ++j) {
- int RSS = RevMap[SS][j];
- DOUT << " Assigning fi#" << RSS << " to " << TRI->getName(Reg) << '\n';
- SlotMapping[RSS] = Reg;
- SlotIsReg.set(RSS);
+ if (AllColored) {
+ MFI->RemoveStackObject(SS);
+ ++NumEliminated;
}
-
- ++NumEliminated;
- Changed = true;
}
DOUT << '\n';
#include "llvm/CodeGen/MachineRegisterInfo.h"
#include "llvm/Target/TargetMachine.h"
#include "llvm/Target/TargetInstrInfo.h"
+#include "llvm/Target/TargetRegisterInfo.h"
#include "llvm/Support/CommandLine.h"
#include "llvm/Support/Compiler.h"
#include "llvm/Support/Debug.h"
bool VirtRegMap::runOnMachineFunction(MachineFunction &mf) {
TII = mf.getTarget().getInstrInfo();
+ TRI = mf.getTarget().getRegisterInfo();
MF = &mf;
ReMatId = MAX_STACK_SLOT+1;
SpillSlotToUsesMap.resize(8);
ImplicitDefed.resize(MF->getRegInfo().getLastVirtReg()+1-
TargetRegisterInfo::FirstVirtualRegister);
+
+ allocatableRCRegs.clear();
+ for (TargetRegisterInfo::regclass_iterator I = TRI->regclass_begin(),
+ E = TRI->regclass_end(); I != E; ++I)
+ allocatableRCRegs.insert(std::make_pair(*I,
+ TRI->getAllocatableSet(mf, *I)));
+
grow();
return false;
class MachineInstr;
class MachineFunction;
class TargetInstrInfo;
+ class TargetRegisterInfo;
class VirtRegMap : public MachineFunctionPass {
public:
private:
const TargetInstrInfo *TII;
-
+ const TargetRegisterInfo *TRI;
MachineFunction *MF;
+
+ DenseMap<const TargetRegisterClass*, BitVector> allocatableRCRegs;
+
/// Virt2PhysMap - This is a virtual to physical register
/// mapping. Each virtual register is required to have an entry in
/// it; even spilled virtual registers (the register mapped to a
unsigned getFirstUnusedRegister(const TargetRegisterClass *RC) {
int Reg = UnusedRegs.find_first();
while (Reg != -1) {
- if (RC->contains(Reg))
+ if (allocatableRCRegs[RC][Reg])
return (unsigned)Reg;
Reg = UnusedRegs.find_next(Reg);
}
#include "llvm/Target/TargetLowering.h"
#include "llvm/Support/Compiler.h"
#include "llvm/Support/Debug.h"
-#include <queue>
-#include <set>
using namespace llvm;
/// MSP430DAGToDAGISel - MSP430 specific code to select MSP430 machine
/// BackEdges - Keep a set of all the loop back edges.
///
- SmallSet<std::pair<BasicBlock*,BasicBlock*>, 8> BackEdges;
+ SmallSet<std::pair<const BasicBlock*, const BasicBlock*>, 8> BackEdges;
public:
static char ID; // Pass identification, replacement for typeid
explicit CodeGenPrepare(const TargetLowering *tli = 0)
bool OptimizeInlineAsmInst(Instruction *I, CallSite CS,
DenseMap<Value*,Value*> &SunkAddrs);
bool OptimizeExtUses(Instruction *I);
- void findLoopBackEdges(Function &F);
+ void findLoopBackEdges(const Function &F);
};
}
/// findLoopBackEdges - Do a DFS walk to find loop back edges.
///
-void CodeGenPrepare::findLoopBackEdges(Function &F) {
- SmallPtrSet<BasicBlock*, 8> Visited;
- SmallVector<std::pair<BasicBlock*, succ_iterator>, 8> VisitStack;
- SmallPtrSet<BasicBlock*, 8> InStack;
-
- BasicBlock *BB = &F.getEntryBlock();
- if (succ_begin(BB) == succ_end(BB))
- return;
- Visited.insert(BB);
- VisitStack.push_back(std::make_pair(BB, succ_begin(BB)));
- InStack.insert(BB);
- do {
- std::pair<BasicBlock*, succ_iterator> &Top = VisitStack.back();
- BasicBlock *ParentBB = Top.first;
- succ_iterator &I = Top.second;
-
- bool FoundNew = false;
- while (I != succ_end(ParentBB)) {
- BB = *I++;
- if (Visited.insert(BB)) {
- FoundNew = true;
- break;
- }
- // Successor is in VisitStack, it's a back edge.
- if (InStack.count(BB))
- BackEdges.insert(std::make_pair(ParentBB, BB));
- }
-
- if (FoundNew) {
- // Go down one level if there is a unvisited successor.
- InStack.insert(BB);
- VisitStack.push_back(std::make_pair(BB, succ_begin(BB)));
- } else {
- // Go up one level.
- std::pair<BasicBlock*, succ_iterator> &Pop = VisitStack.back();
- InStack.erase(Pop.first);
- VisitStack.pop_back();
- }
- } while (!VisitStack.empty());
+void CodeGenPrepare::findLoopBackEdges(const Function &F) {
+ SmallVector<std::pair<const BasicBlock*,const BasicBlock*>, 32> Edges;
+ FindFunctionBackedges(F, Edges);
+
+ BackEdges.insert(Edges.begin(), Edges.end());
}
/// 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<BasicBlock*,BasicBlock*>, 8> &BackEdges,
+ SmallSet<std::pair<const BasicBlock*,
+ const BasicBlock*>, 8> &BackEdges,
Pass *P) {
BasicBlock *TIBB = TI->getParent();
BasicBlock *Dest = TI->getSuccessor(SuccNum);
#include "llvm/Transforms/Scalar.h"
#include "llvm/IntrinsicInst.h"
#include "llvm/Pass.h"
-#include "llvm/ADT/DenseMap.h"
-#include "llvm/ADT/Statistic.h"
-#include "llvm/ADT/STLExtras.h"
#include "llvm/Analysis/ConstantFolding.h"
#include "llvm/Transforms/Utils/BasicBlockUtils.h"
#include "llvm/Transforms/Utils/Local.h"
#include "llvm/Target/TargetData.h"
+#include "llvm/ADT/DenseMap.h"
+#include "llvm/ADT/Statistic.h"
+#include "llvm/ADT/STLExtras.h"
+#include "llvm/ADT/SmallPtrSet.h"
+#include "llvm/ADT/SmallSet.h"
#include "llvm/Support/CommandLine.h"
#include "llvm/Support/Compiler.h"
#include "llvm/Support/Debug.h"
-#include "llvm/ADT/SmallPtrSet.h"
+#include "llvm/Support/ValueHandle.h"
using namespace llvm;
STATISTIC(NumThreads, "Number of jumps threaded");
///
class VISIBILITY_HIDDEN JumpThreading : public FunctionPass {
TargetData *TD;
+#ifdef NDEBUG
+ SmallPtrSet<BasicBlock*, 16> LoopHeaders;
+#else
+ SmallSet<AssertingVH<BasicBlock>, 16> LoopHeaders;
+#endif
public:
static char ID; // Pass identification
JumpThreading() : FunctionPass(&ID) {}
}
bool runOnFunction(Function &F);
+ void FindLoopHeaders(Function &F);
+
bool ProcessBlock(BasicBlock *BB);
- void ThreadEdge(BasicBlock *BB, BasicBlock *PredBB, BasicBlock *SuccBB);
+ bool ThreadEdge(BasicBlock *BB, BasicBlock *PredBB, BasicBlock *SuccBB,
+ unsigned JumpThreadCost);
BasicBlock *FactorCommonPHIPreds(PHINode *PN, Constant *CstVal);
bool ProcessBranchOnDuplicateCond(BasicBlock *PredBB, BasicBlock *DestBB);
bool ProcessSwitchOnDuplicateCond(BasicBlock *PredBB, BasicBlock *DestBB);
DOUT << "Jump threading on function '" << F.getNameStart() << "'\n";
TD = &getAnalysis<TargetData>();
+ FindLoopHeaders(F);
+
bool AnotherIteration = true, EverChanged = false;
while (AnotherIteration) {
AnotherIteration = false;
BB != &BB->getParent()->getEntryBlock()) {
DOUT << " JT: Deleting dead block '" << BB->getNameStart()
<< "' with terminator: " << *BB->getTerminator();
+ LoopHeaders.erase(BB);
DeleteDeadBlock(BB);
Changed = true;
}
AnotherIteration = Changed;
EverChanged |= Changed;
}
+
+ LoopHeaders.clear();
return EverChanged;
}
+/// FindLoopHeaders - We do not want jump threading to turn proper loop
+/// structures into irreducible loops. Doing this breaks up the loop nesting
+/// hierarchy and pessimizes later transformations. To prevent this from
+/// happening, we first have to find the loop headers. Here we approximate this
+/// by finding targets of backedges in the CFG.
+///
+/// Note that there definitely are cases when we want to allow threading of
+/// edges across a loop header. For example, threading a jump from outside the
+/// loop (the preheader) to an exit block of the loop is definitely profitable.
+/// It is also almost always profitable to thread backedges from within the loop
+/// to exit blocks, and is often profitable to thread backedges to other blocks
+/// within the loop (forming a nested loop). This simple analysis is not rich
+/// enough to track all of these properties and keep it up-to-date as the CFG
+/// mutates, so we don't allow any of these transformations.
+///
+void JumpThreading::FindLoopHeaders(Function &F) {
+ SmallVector<std::pair<const BasicBlock*,const BasicBlock*>, 32> Edges;
+ FindFunctionBackedges(F, Edges);
+
+ for (unsigned i = 0, e = Edges.size(); i != e; ++i)
+ LoopHeaders.insert(const_cast<BasicBlock*>(Edges[i].second));
+}
+
+
/// FactorCommonPHIPreds - If there are multiple preds with the same incoming
/// value for the PHI, factor them together so we get one block to thread for
/// the whole group.
if (BasicBlock *SinglePred = BB->getSinglePredecessor())
if (SinglePred->getTerminator()->getNumSuccessors() == 1 &&
SinglePred != BB) {
+ // If SinglePred was a loop header, BB becomes one.
+ if (LoopHeaders.erase(SinglePred))
+ LoopHeaders.insert(BB);
+
// 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();
// Next, figure out which successor we are threading to.
BasicBlock *SuccBB = DestBI->getSuccessor(!BranchDir);
- // If threading to the same block as we come from, we would infinite loop.
- if (SuccBB == BB) {
- DOUT << " Not threading BB '" << BB->getNameStart()
- << "' - would thread to self!\n";
- return false;
- }
-
- // And finally, do it!
- DOUT << " Threading edge from '" << PredBB->getNameStart() << "' to '"
- << SuccBB->getNameStart() << "' with cost: " << JumpThreadCost
- << ", across block:\n "
- << *BB << "\n";
-
- ThreadEdge(BB, PredBB, SuccBB);
- ++NumThreads;
- return true;
+ // Ok, try to thread it!
+ return ThreadEdge(BB, PredBB, SuccBB, JumpThreadCost);
}
/// ProcessSwitchOnDuplicateCond - We found a block and a predecessor of that
SuccBB = SI->getSuccessor(SI->findCaseValue(PredCst));
}
- // If threading to the same block as we come from, we would infinite loop.
- if (SuccBB == BB) {
- DOUT << " Not threading BB '" << BB->getNameStart()
- << "' - would thread to self!\n";
- return false;
- }
-
- // And finally, do it!
- DOUT << " Threading edge from '" << PredBB->getNameStart() << "' to '"
- << SuccBB->getNameStart() << "' with cost: " << JumpThreadCost
- << ", across block:\n "
- << *BB << "\n";
-
- ThreadEdge(BB, PredBB, SuccBB);
- ++NumThreads;
- return true;
+ // Ok, try to thread it!
+ return ThreadEdge(BB, PredBB, SuccBB, JumpThreadCost);
}
/// ProcessJumpOnLogicalPHI - PN's basic block contains a conditional branch
// 'true' block.
BasicBlock *SuccBB = BB->getTerminator()->getSuccessor(isAnd);
- // If threading to the same block as we come from, we would infinite loop.
- if (SuccBB == BB) {
- DOUT << " Not threading BB '" << BB->getNameStart()
- << "' - would thread to self!\n";
- return false;
- }
-
- // And finally, do it!
- DOUT << " Threading edge through bool from '" << PredBB->getNameStart()
- << "' to '" << SuccBB->getNameStart() << "' with cost: "
- << JumpThreadCost << ", across block:\n "
- << *BB << "\n";
-
- ThreadEdge(BB, PredBB, SuccBB);
- ++NumThreads;
- return true;
+ // Ok, try to thread it!
+ return ThreadEdge(BB, PredBB, SuccBB, JumpThreadCost);
}
/// ProcessBranchOnCompare - We found a branch on a comparison between a phi
// Next, get our successor.
BasicBlock *SuccBB = BB->getTerminator()->getSuccessor(!TrueDirection);
+ // Ok, try to thread it!
+ return ThreadEdge(BB, PredBB, SuccBB, JumpThreadCost);
+}
+
+
+/// ThreadEdge - We have decided that it is safe and profitable to thread an
+/// edge from PredBB to SuccBB across BB. Transform the IR to reflect this
+/// change.
+bool JumpThreading::ThreadEdge(BasicBlock *BB, BasicBlock *PredBB,
+ BasicBlock *SuccBB, unsigned JumpThreadCost) {
+
// If threading to the same block as we come from, we would infinite loop.
if (SuccBB == BB) {
- DOUT << " Not threading BB '" << BB->getNameStart()
- << "' - would thread to self!\n";
+ DOUT << " Not threading across BB '" << BB->getNameStart()
+ << "' - would thread to self!\n";
return false;
}
-
+ // If threading this would thread across a loop header, don't thread the edge.
+ // See the comments above FindLoopHeaders for justifications and caveats.
+ if (LoopHeaders.count(BB)) {
+ DOUT << " Not threading from '" << PredBB->getNameStart()
+ << "' across loop header BB '" << BB->getNameStart()
+ << "' to dest BB '" << SuccBB->getNameStart()
+ << "' - it might create an irreducible loop!\n";
+ return false;
+ }
+
// And finally, do it!
- DOUT << " Threading edge through bool from '" << PredBB->getNameStart()
- << "' to '" << SuccBB->getNameStart() << "' with cost: "
- << JumpThreadCost << ", across block:\n "
+ DOUT << " Threading edge from '" << PredBB->getNameStart() << "' to '"
+ << SuccBB->getNameStart() << "' with cost: " << JumpThreadCost
+ << ", across block:\n "
<< *BB << "\n";
- ThreadEdge(BB, PredBB, SuccBB);
- ++NumThreads;
- return true;
-}
-
-
-/// ThreadEdge - We have decided that it is safe and profitable to thread an
-/// edge from PredBB to SuccBB across BB. Transform the IR to reflect this
-/// change.
-void JumpThreading::ThreadEdge(BasicBlock *BB, BasicBlock *PredBB,
- BasicBlock *SuccBB) {
-
// Jump Threading can not update SSA properties correctly if the values
// defined in the duplicated block are used outside of the block itself. For
// this reason, we spill all values that are used outside of BB to the stack.
RecursivelyDeleteTriviallyDeadInstructions(Inst);
}
+
+ // Threaded an edge!
+ ++NumThreads;
+ return true;
}
return NewBB;
}
+/// FindFunctionBackedges - Analyze the specified function to find all of the
+/// loop backedges in the function and return them. This is a relatively cheap
+/// (compared to computing dominators and loop info) analysis.
+///
+/// The output is added to Result, as pairs of <from,to> edge info.
+void llvm::FindFunctionBackedges(const Function &F,
+ SmallVectorImpl<std::pair<const BasicBlock*,const BasicBlock*> > &Result) {
+ const BasicBlock *BB = &F.getEntryBlock();
+ if (succ_begin(BB) == succ_end(BB))
+ return;
+
+ SmallPtrSet<const BasicBlock*, 8> Visited;
+ SmallVector<std::pair<const BasicBlock*, succ_const_iterator>, 8> VisitStack;
+ SmallPtrSet<const BasicBlock*, 8> InStack;
+
+ Visited.insert(BB);
+ VisitStack.push_back(std::make_pair(BB, succ_begin(BB)));
+ InStack.insert(BB);
+ do {
+ std::pair<const BasicBlock*, succ_const_iterator> &Top = VisitStack.back();
+ const BasicBlock *ParentBB = Top.first;
+ succ_const_iterator &I = Top.second;
+
+ bool FoundNew = false;
+ while (I != succ_end(ParentBB)) {
+ BB = *I++;
+ if (Visited.insert(BB)) {
+ FoundNew = true;
+ break;
+ }
+ // Successor is in VisitStack, it's a back edge.
+ if (InStack.count(BB))
+ Result.push_back(std::make_pair(ParentBB, BB));
+ }
+
+ if (FoundNew) {
+ // Go down one level if there is a unvisited successor.
+ InStack.insert(BB);
+ VisitStack.push_back(std::make_pair(BB, succ_begin(BB)));
+ } else {
+ // Go up one level.
+ InStack.erase(VisitStack.pop_back_val().first);
+ }
+ } while (!VisitStack.empty());
+
+
+}
+
+
+
/// AreEquivalentAddressValues - Test if A and B will obviously have the same
/// value. This includes recognizing that %t0 and %t1 will have the same
/// value in code like this:
typedef DenseMap<Value*, ValueHandleBase*> ValueHandlesTy;
static ManagedStatic<ValueHandlesTy> ValueHandles;
-/// AddToUseList - Add this ValueHandle to the use list for VP, where List is
-/// known to point into the existing use list.
+/// AddToExistingUseList - Add this ValueHandle to the use list for VP, where
+/// List is known to point into the existing use list.
void ValueHandleBase::AddToExistingUseList(ValueHandleBase **List) {
assert(List && "Handle list is null?");
ValueHandleBase *&Entry = Handles[VP];
assert(Entry == 0 && "Value really did already have handles?");
AddToExistingUseList(&Entry);
- VP->HasValueHandle = 1;
+ VP->HasValueHandle = true;
// If reallocation didn't happen or if this was the first insertion, don't
// walk the table.
-; RUN: llvm-as < %s | llc | grep "m.h" | count 1
+; RUN: llvm-as < %s | llc | grep "\\"m.h\\"" | count 1
target triple = "i386-apple-darwin9.6"
%llvm.dbg.anchor.type = type { i32, i32 }
%llvm.dbg.basictype.type = type { i32, { }*, i8*, { }*, i32, i64, i64, i64, i32, i32 }
--- /dev/null
+// RUN: %llvmgxx -S -emit-llvm %s -o - | grep nounwind | count 4
+int c(void) __attribute__((const));
+int p(void) __attribute__((pure));
+int t(void);
+
+int f(void) {
+ return c() + p() + t();
+}
--- /dev/null
+// RUN: %llvmgcc -S -m32 -mregparm=3 %s -emit-llvm -o - | grep {inreg %action}
+// XTARGET: x86
+// PR3967
+
+enum kobject_action {
+ KOBJ_ADD,
+ KOBJ_REMOVE,
+ KOBJ_CHANGE,
+ KOBJ_MOVE,
+ KOBJ_ONLINE,
+ KOBJ_OFFLINE,
+ KOBJ_MAX
+};
+
+struct kobject;
+
+int kobject_uevent(struct kobject *kobj, enum kobject_action action) {}
ret i1 %val
}
+declare void @throw_if_bit_set(i8*, i8) readonly
+define i1 @c6(i8* %q, i8 %bit) {
+ invoke void @throw_if_bit_set(i8* %q, i8 %bit)
+ to label %ret0 unwind label %ret1
+ret0:
+ ret i1 0
+ret1:
+ ret i1 1
+}
+
define i32 @nc1(i32* %q, i32* %p, i1 %b) {
e:
br label %l
ret void
}
-declare void @external(i8*) readonly
+declare void @external(i8*) readonly nounwind
define void @nc4(i8* %p) {
call void @external(i8* %p)
ret void
}
-define void @nc5(void (i8*)* %f, i8* %p) {
- call void %f(i8* %p) readonly
- call void %f(i8* nocapture %p)
+define void @nc5(void (i8*)* %p, i8* %r) {
+ call void %p(i8* %r)
+ call void %p(i8* nocapture %r)
+ ret void
+}
+
+declare i8* @external_identity(i8*) readonly nounwind
+define void @nc6(i8* %p) {
+ call i8* @external_identity(i8* %p)
ret void
}
--- /dev/null
+; RUN: llvm-as < %s | opt -jump-threading -loop-rotate -instcombine -indvars -loop-unroll -simplifycfg | llvm-dis > %t
+; RUN: grep {volatile store} %t | count 3
+; RUN: not grep {br label} %t
+
+; Jump threading should not prevent this loop from being unrolled.
+
+target datalayout = "e-p:32:32:32-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:32:64-f32:32:32-f64:32:64-v64:64:64-v128:128:128-a0:0:64-f80:128:128"
+target triple = "i386-apple-darwin9.6"
+@v1 = external global i32 ; <i32*> [#uses=2]
+
+define i32 @unroll() nounwind {
+entry:
+ br label %bb4
+
+bb: ; preds = %bb4
+ %0 = icmp eq i32 %i.0, 0 ; <i1> [#uses=1]
+ br i1 %0, label %bb1, label %bb2
+
+bb1: ; preds = %bb
+ volatile store i32 1000, i32* @v1, align 4
+ br label %bb3
+
+bb2: ; preds = %bb
+ volatile store i32 1001, i32* @v1, align 4
+ br label %bb3
+
+bb3: ; preds = %bb2, %bb1
+ %1 = add i32 %i.0, 1 ; <i32> [#uses=1]
+ br label %bb4
+
+bb4: ; preds = %bb3, %entry
+ %i.0 = phi i32 [ 0, %entry ], [ %1, %bb3 ] ; <i32> [#uses=3]
+ %2 = icmp sgt i32 %i.0, 2 ; <i1> [#uses=1]
+ br i1 %2, label %bb5, label %bb
+
+bb5: ; preds = %bb4
+ ret i32 0
+}
O << "\";\n\n";
O << " if (TAI->doesSupportDebugInformation() &&\n"
- << " DW->ShouldEmitDwarfDebug() && OptLevel != CodeGenOpt::None) {\n"
+ << " DW->ShouldEmitDwarfDebug()) {\n"
<< " DebugLoc CurDL = MI->getDebugLoc();\n\n"
<< " if (!CurDL.isUnknown()) {\n"
<< " static DebugLocTuple PrevDLT(0, ~0U, ~0U);\n"
<< " DebugLocTuple CurDLT = MF->getDebugLocTuple(CurDL);\n\n"
- << " if (PrevDLT.CompileUnit != 0 && PrevDLT != CurDLT)\n"
+ << " if (CurDLT.CompileUnit != 0 && PrevDLT != CurDLT)\n"
<< " printLabel(DW->RecordSourceLine(CurDLT.Line, CurDLT.Col,\n"
<< " DICompileUnit(CurDLT.CompileUnit)));\n\n"
<< " PrevDLT = CurDLT;\n"
OS << "// Include standard, target-independent definitions and methods used\n"
<< "// by the instruction selector.\n";
- OS << "#include <llvm/CodeGen/DAGISelHeader.h>\n\n";
+ OS << "#include \"llvm/CodeGen/DAGISelHeader.h\"\n\n";
EmitNodeTransforms(OS);
EmitPredicateFunctions(OS);
projects / oota-llvm.git / commitdiff