From 38bdfc69cbe370ce5f623df4449afa32cda97422 Mon Sep 17 00:00:00 2001 From: Evan Cheng Date: Sun, 18 Oct 2009 19:58:47 +0000 Subject: [PATCH] Spill slots cannot alias. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@84432 91177308-0d34-0410-b5e6-96231b3b80d8 --- include/llvm/CodeGen/PseudoSourceValue.h | 2 +- lib/CodeGen/PseudoSourceValue.cpp | 11 +++++++---- lib/CodeGen/ScheduleDAGInstrs.cpp | 13 ++++++++----- lib/CodeGen/ScheduleDAGInstrs.h | 1 + 4 files changed, 17 insertions(+), 10 deletions(-) diff --git a/include/llvm/CodeGen/PseudoSourceValue.h b/include/llvm/CodeGen/PseudoSourceValue.h index aaf1f5f8986..7a9122d89f9 100644 --- a/include/llvm/CodeGen/PseudoSourceValue.h +++ b/include/llvm/CodeGen/PseudoSourceValue.h @@ -41,7 +41,7 @@ namespace llvm { /// isAliased - Test whether the memory pointed to by this /// PseudoSourceValue may also be pointed to by an LLVM IR Value. - virtual bool isAliased() const; + virtual bool isAliased(const MachineFrameInfo *) const; /// classof - Methods for support type inquiry through isa, cast, and /// dyn_cast: diff --git a/lib/CodeGen/PseudoSourceValue.cpp b/lib/CodeGen/PseudoSourceValue.cpp index 289a52b62a9..70e864050a6 100644 --- a/lib/CodeGen/PseudoSourceValue.cpp +++ b/lib/CodeGen/PseudoSourceValue.cpp @@ -63,7 +63,7 @@ namespace { virtual bool isConstant(const MachineFrameInfo *MFI) const; - virtual bool isAliased() const; + virtual bool isAliased(const MachineFrameInfo *MFI) const; virtual void printCustom(raw_ostream &OS) const { OS << "FixedStack" << FI; @@ -91,7 +91,7 @@ bool PseudoSourceValue::isConstant(const MachineFrameInfo *) const { return false; } -bool PseudoSourceValue::isAliased() const { +bool PseudoSourceValue::isAliased(const MachineFrameInfo *MFI) const { if (this == getStack() || this == getGOT() || this == getConstantPool() || @@ -105,9 +105,12 @@ bool FixedStackPseudoSourceValue::isConstant(const MachineFrameInfo *MFI) const{ return MFI && MFI->isImmutableObjectIndex(FI); } -bool FixedStackPseudoSourceValue::isAliased() const{ +bool FixedStackPseudoSourceValue::isAliased(const MachineFrameInfo *MFI) const { // Negative frame indices are used for special things that don't // appear in LLVM IR. Non-negative indices may be used for things // like static allocas. - return FI >= 0; + if (!MFI) + return FI >= 0; + // Spill slots should not alias others. + return !MFI->isFixedObjectIndex(FI) && !MFI->isSpillSlotObjectIndex(FI); } diff --git a/lib/CodeGen/ScheduleDAGInstrs.cpp b/lib/CodeGen/ScheduleDAGInstrs.cpp index 768ca1631a8..43454dd1cbe 100644 --- a/lib/CodeGen/ScheduleDAGInstrs.cpp +++ b/lib/CodeGen/ScheduleDAGInstrs.cpp @@ -32,7 +32,9 @@ using namespace llvm; ScheduleDAGInstrs::ScheduleDAGInstrs(MachineFunction &mf, const MachineLoopInfo &mli, const MachineDominatorTree &mdt) - : ScheduleDAG(mf), MLI(mli), MDT(mdt), LoopRegs(MLI, MDT) {} + : ScheduleDAG(mf), MLI(mli), MDT(mdt), LoopRegs(MLI, MDT) { + MFI = mf.getFrameInfo(); +} /// Run - perform scheduling. /// @@ -95,7 +97,8 @@ static const Value *getUnderlyingObject(const Value *V) { /// getUnderlyingObjectForInstr - If this machine instr has memory reference /// information and it can be tracked to a normal reference to a known /// object, return the Value for that object. Otherwise return null. -static const Value *getUnderlyingObjectForInstr(const MachineInstr *MI) { +static const Value *getUnderlyingObjectForInstr(const MachineInstr *MI, + const MachineFrameInfo *MFI) { if (!MI->hasOneMemOperand() || !(*MI->memoperands_begin())->getValue() || (*MI->memoperands_begin())->isVolatile()) @@ -110,7 +113,7 @@ static const Value *getUnderlyingObjectForInstr(const MachineInstr *MI) { // For now, ignore PseudoSourceValues which may alias LLVM IR values // because the code that uses this function has no way to cope with // such aliases. - if (PSV->isAliased()) + if (PSV->isAliased(MFI)) return 0; return V; } @@ -353,7 +356,7 @@ void ScheduleDAGInstrs::BuildSchedGraph(AliasAnalysis *AA) { // Unknown memory accesses. Assume the worst. ChainMMO = 0; } else if (TID.mayStore()) { - if (const Value *V = getUnderlyingObjectForInstr(MI)) { + if (const Value *V = getUnderlyingObjectForInstr(MI, MFI)) { // A store to a specific PseudoSourceValue. Add precise dependencies. // Handle the def in MemDefs, if there is one. std::map::iterator I = MemDefs.find(V); @@ -386,7 +389,7 @@ void ScheduleDAGInstrs::BuildSchedGraph(AliasAnalysis *AA) { } else if (TID.mayLoad()) { if (MI->isInvariantLoad(AA)) { // Invariant load, no chain dependencies needed! - } else if (const Value *V = getUnderlyingObjectForInstr(MI)) { + } else if (const Value *V = getUnderlyingObjectForInstr(MI, MFI)) { // A load from a specific PseudoSourceValue. Add precise dependencies. std::map::iterator I = MemDefs.find(V); if (I != MemDefs.end()) diff --git a/lib/CodeGen/ScheduleDAGInstrs.h b/lib/CodeGen/ScheduleDAGInstrs.h index 29e1c98cb31..366c3a859d6 100644 --- a/lib/CodeGen/ScheduleDAGInstrs.h +++ b/lib/CodeGen/ScheduleDAGInstrs.h @@ -98,6 +98,7 @@ namespace llvm { class VISIBILITY_HIDDEN ScheduleDAGInstrs : public ScheduleDAG { const MachineLoopInfo &MLI; const MachineDominatorTree &MDT; + const MachineFrameInfo *MFI; /// Defs, Uses - Remember where defs and uses of each physical register /// are as we iterate upward through the instructions. This is allocated