X-Git-Url: http://plrg.eecs.uci.edu/git/?a=blobdiff_plain;f=lib%2FCodeGen%2FPrologEpilogInserter.cpp;h=939c50027b0224af47bdac1b51a8182028cec9b4;hb=d42ae6b473171fbf4cdc1defd2e5d2fb1a40fe86;hp=e4f359c213c4c201b9264d1ced402d028e70edd7;hpb=2f7322b3480ede79b80d2aac5f1827e277f4dbee;p=oota-llvm.git diff --git a/lib/CodeGen/PrologEpilogInserter.cpp b/lib/CodeGen/PrologEpilogInserter.cpp index e4f359c213c..939c50027b0 100644 --- a/lib/CodeGen/PrologEpilogInserter.cpp +++ b/lib/CodeGen/PrologEpilogInserter.cpp @@ -71,8 +71,9 @@ private: // stack frame indexes. unsigned MinCSFrameIndex, MaxCSFrameIndex; - // Save and Restore blocks of the current function. - MachineBasicBlock *SaveBlock; + // Save and Restore blocks of the current function. Typically there is a + // single save block, unless Windows EH funclets are involved. + SmallVector SaveBlocks; SmallVector RestoreBlocks; // Flag to control whether to use the register scavenger to resolve @@ -82,7 +83,8 @@ private: void calculateSets(MachineFunction &Fn); void calculateCallsInformation(MachineFunction &Fn); - void calculateCalleeSavedRegisters(MachineFunction &Fn); + void assignCalleeSavedSpillSlots(MachineFunction &Fn, + const BitVector &SavedRegs); void insertCSRSpillsAndRestores(MachineFunction &Fn); void calculateFrameObjectOffsets(MachineFunction &Fn); void replaceFrameIndices(MachineFunction &Fn); @@ -90,9 +92,6 @@ private: int &SPAdj); void scavengeFrameVirtualRegs(MachineFunction &Fn); void insertPrologEpilogCode(MachineFunction &Fn); - - // Convenience for recognizing return blocks. - bool isReturnBlock(MachineBasicBlock *MBB); }; } // namespace @@ -127,10 +126,6 @@ void PEI::getAnalysisUsage(AnalysisUsage &AU) const { MachineFunctionPass::getAnalysisUsage(AU); } -bool PEI::isReturnBlock(MachineBasicBlock* MBB) { - return (MBB && !MBB->empty() && MBB->back().isReturn()); -} - /// Compute the set of return blocks void PEI::calculateSets(MachineFunction &Fn) { const MachineFrameInfo *MFI = Fn.getFrameInfo(); @@ -141,20 +136,25 @@ void PEI::calculateSets(MachineFunction &Fn) { // Use the points found by shrink-wrapping, if any. if (MFI->getSavePoint()) { - SaveBlock = MFI->getSavePoint(); + SaveBlocks.push_back(MFI->getSavePoint()); assert(MFI->getRestorePoint() && "Both restore and save must be set"); - RestoreBlocks.push_back(MFI->getRestorePoint()); + MachineBasicBlock *RestoreBlock = MFI->getRestorePoint(); + // If RestoreBlock does not have any successor and is not a return block + // then the end point is unreachable and we do not need to insert any + // epilogue. + if (!RestoreBlock->succ_empty() || RestoreBlock->isReturnBlock()) + RestoreBlocks.push_back(RestoreBlock); return; } // Save refs to entry and return blocks. - SaveBlock = Fn.begin(); - for (MachineFunction::iterator MBB = Fn.begin(), E = Fn.end(); - MBB != E; ++MBB) - if (isReturnBlock(MBB)) - RestoreBlocks.push_back(MBB); - - return; + SaveBlocks.push_back(&Fn.front()); + for (MachineBasicBlock &MBB : Fn) { + if (MBB.isEHFuncletEntry()) + SaveBlocks.push_back(&MBB); + if (MBB.isReturnBlock()) + RestoreBlocks.push_back(&MBB); + } } /// StackObjSet - A set of stack object indexes @@ -178,19 +178,18 @@ bool PEI::runOnMachineFunction(MachineFunction &Fn) { // instructions. calculateCallsInformation(Fn); - // Allow the target machine to make some adjustments to the function - // e.g. UsedPhysRegs before calculateCalleeSavedRegisters. - TFI->processFunctionBeforeCalleeSavedScan(Fn, RS); + // Determine which of the registers in the callee save list should be saved. + BitVector SavedRegs; + TFI->determineCalleeSaves(Fn, SavedRegs, RS); - // Scan the function for modified callee saved registers and insert spill code - // for any callee saved registers that are modified. - calculateCalleeSavedRegisters(Fn); + // Insert spill code for any callee saved registers that are modified. + assignCalleeSavedSpillSlots(Fn, SavedRegs); // Determine placement of CSR spill/restore code: // place all spills in the entry block, all restores in return blocks. calculateSets(Fn); - // Add the code to save and restore the callee saved registers + // Add the code to save and restore the callee saved registers. if (!F->hasFnAttribute(Attribute::Naked)) insertCSRSpillsAndRestores(Fn); @@ -232,6 +231,7 @@ bool PEI::runOnMachineFunction(MachineFunction &Fn) { } delete RS; + SaveBlocks.clear(); RestoreBlocks.clear(); return true; } @@ -248,12 +248,12 @@ void PEI::calculateCallsInformation(MachineFunction &Fn) { bool AdjustsStack = MFI->adjustsStack(); // Get the function call frame set-up and tear-down instruction opcode - int FrameSetupOpcode = TII.getCallFrameSetupOpcode(); - int FrameDestroyOpcode = TII.getCallFrameDestroyOpcode(); + unsigned FrameSetupOpcode = TII.getCallFrameSetupOpcode(); + unsigned FrameDestroyOpcode = TII.getCallFrameDestroyOpcode(); // Early exit for targets which have no call frame setup/destroy pseudo // instructions. - if (FrameSetupOpcode == -1 && FrameDestroyOpcode == -1) + if (FrameSetupOpcode == ~0u && FrameDestroyOpcode == ~0u) return; std::vector FrameSDOps; @@ -290,39 +290,27 @@ void PEI::calculateCallsInformation(MachineFunction &Fn) { } } - -/// calculateCalleeSavedRegisters - Scan the function for modified callee saved -/// registers. -void PEI::calculateCalleeSavedRegisters(MachineFunction &F) { - const TargetRegisterInfo *RegInfo = F.getSubtarget().getRegisterInfo(); - const TargetFrameLowering *TFI = F.getSubtarget().getFrameLowering(); - MachineFrameInfo *MFI = F.getFrameInfo(); - - // Get the callee saved register list... - const MCPhysReg *CSRegs = RegInfo->getCalleeSavedRegs(&F); - +void PEI::assignCalleeSavedSpillSlots(MachineFunction &F, + const BitVector &SavedRegs) { // These are used to keep track the callee-save area. Initialize them. MinCSFrameIndex = INT_MAX; MaxCSFrameIndex = 0; - // Early exit for targets which have no callee saved registers. - if (!CSRegs || CSRegs[0] == 0) + if (SavedRegs.empty()) return; - // In Naked functions we aren't going to save any registers. - if (F.getFunction()->hasFnAttribute(Attribute::Naked)) - return; + const TargetRegisterInfo *RegInfo = F.getSubtarget().getRegisterInfo(); + const MCPhysReg *CSRegs = RegInfo->getCalleeSavedRegs(&F); std::vector CSI; for (unsigned i = 0; CSRegs[i]; ++i) { unsigned Reg = CSRegs[i]; - // Functions which call __builtin_unwind_init get all their registers saved. - if (F.getRegInfo().isPhysRegUsed(Reg) || F.getMMI().callsUnwindInit()) { - // If the reg is modified, save it! + if (SavedRegs.test(Reg)) CSI.push_back(CalleeSavedInfo(Reg)); - } } + const TargetFrameLowering *TFI = F.getSubtarget().getFrameLowering(); + MachineFrameInfo *MFI = F.getFrameInfo(); if (!TFI->assignCalleeSavedSpillSlots(F, RegInfo, CSI)) { // If target doesn't implement this, use generic code. @@ -414,7 +402,7 @@ static void updateLiveness(MachineFunction &MF) { const MachineBasicBlock *CurBB = WorkList.pop_back_val(); // By construction, the region that is after the save point is // dominated by the Save and post-dominated by the Restore. - if (CurBB == Save) + if (CurBB == Save && Save != Restore) continue; // Enqueue all the successors not already visited. // Those are by construction either before Save or after Restore. @@ -426,10 +414,13 @@ static void updateLiveness(MachineFunction &MF) { const std::vector &CSI = MFI->getCalleeSavedInfo(); for (unsigned i = 0, e = CSI.size(); i != e; ++i) { - for (MachineBasicBlock *MBB : Visited) + for (MachineBasicBlock *MBB : Visited) { + MCPhysReg Reg = CSI[i].getReg(); // Add the callee-saved register as live-in. // It's killed at the spill. - MBB->addLiveIn(CSI[i].getReg()); + if (!MBB->isLiveIn(Reg)) + MBB->addLiveIn(Reg); + } } } @@ -453,18 +444,20 @@ void PEI::insertCSRSpillsAndRestores(MachineFunction &Fn) { MachineBasicBlock::iterator I; // Spill using target interface. - I = SaveBlock->begin(); - if (!TFI->spillCalleeSavedRegisters(*SaveBlock, I, CSI, TRI)) { - for (unsigned i = 0, e = CSI.size(); i != e; ++i) { - // Insert the spill to the stack frame. - unsigned Reg = CSI[i].getReg(); - const TargetRegisterClass *RC = TRI->getMinimalPhysRegClass(Reg); - TII.storeRegToStackSlot(*SaveBlock, I, Reg, true, CSI[i].getFrameIdx(), - RC, TRI); + for (MachineBasicBlock *SaveBlock : SaveBlocks) { + I = SaveBlock->begin(); + if (!TFI->spillCalleeSavedRegisters(*SaveBlock, I, CSI, TRI)) { + for (unsigned i = 0, e = CSI.size(); i != e; ++i) { + // Insert the spill to the stack frame. + unsigned Reg = CSI[i].getReg(); + const TargetRegisterClass *RC = TRI->getMinimalPhysRegClass(Reg); + TII.storeRegToStackSlot(*SaveBlock, I, Reg, true, CSI[i].getFrameIdx(), + RC, TRI); + } } + // Update the live-in information of all the blocks up to the save point. + updateLiveness(Fn); } - // Update the live-in information of all the blocks up to the save point. - updateLiveness(Fn); // Restore using target interface. for (MachineBasicBlock *MBB : RestoreBlocks) { @@ -507,7 +500,7 @@ void PEI::insertCSRSpillsAndRestores(MachineFunction &Fn) { static inline void AdjustStackOffset(MachineFrameInfo *MFI, int FrameIdx, bool StackGrowsDown, int64_t &Offset, - unsigned &MaxAlign) { + unsigned &MaxAlign, unsigned Skew) { // If the stack grows down, add the object size to find the lowest address. if (StackGrowsDown) Offset += MFI->getObjectSize(FrameIdx); @@ -519,7 +512,7 @@ AdjustStackOffset(MachineFrameInfo *MFI, int FrameIdx, MaxAlign = std::max(MaxAlign, Align); // Adjust to alignment boundary. - Offset = (Offset + Align - 1) / Align * Align; + Offset = RoundUpToAlignment(Offset, Align, Skew); if (StackGrowsDown) { DEBUG(dbgs() << "alloc FI(" << FrameIdx << ") at SP[" << -Offset << "]\n"); @@ -537,12 +530,12 @@ static void AssignProtectedObjSet(const StackObjSet &UnassignedObjs, SmallSet &ProtectedObjs, MachineFrameInfo *MFI, bool StackGrowsDown, - int64_t &Offset, unsigned &MaxAlign) { + int64_t &Offset, unsigned &MaxAlign, unsigned Skew) { for (StackObjSet::const_iterator I = UnassignedObjs.begin(), E = UnassignedObjs.end(); I != E; ++I) { int i = *I; - AdjustStackOffset(MFI, i, StackGrowsDown, Offset, MaxAlign); + AdjustStackOffset(MFI, i, StackGrowsDown, Offset, MaxAlign, Skew); ProtectedObjs.insert(i); } } @@ -570,6 +563,9 @@ void PEI::calculateFrameObjectOffsets(MachineFunction &Fn) { && "Local area offset should be in direction of stack growth"); int64_t Offset = LocalAreaOffset; + // Skew to be applied to alignment. + unsigned Skew = TFI.getStackAlignmentSkew(Fn); + // If there are fixed sized objects that are preallocated in the local area, // non-fixed objects can't be allocated right at the start of local area. // We currently don't support filling in holes in between fixed sized @@ -600,7 +596,7 @@ void PEI::calculateFrameObjectOffsets(MachineFunction &Fn) { unsigned Align = MFI->getObjectAlignment(i); // Adjust to alignment boundary - Offset = RoundUpToAlignment(Offset, Align); + Offset = RoundUpToAlignment(Offset, Align, Skew); MFI->setObjectOffset(i, -Offset); // Set the computed offset } @@ -609,7 +605,7 @@ void PEI::calculateFrameObjectOffsets(MachineFunction &Fn) { for (int i = MaxCSFI; i >= MinCSFI ; --i) { unsigned Align = MFI->getObjectAlignment(i); // Adjust to alignment boundary - Offset = RoundUpToAlignment(Offset, Align); + Offset = RoundUpToAlignment(Offset, Align, Skew); MFI->setObjectOffset(i, Offset); Offset += MFI->getObjectSize(i); @@ -631,7 +627,7 @@ void PEI::calculateFrameObjectOffsets(MachineFunction &Fn) { RS->getScavengingFrameIndices(SFIs); for (SmallVectorImpl::iterator I = SFIs.begin(), IE = SFIs.end(); I != IE; ++I) - AdjustStackOffset(MFI, *I, StackGrowsDown, Offset, MaxAlign); + AdjustStackOffset(MFI, *I, StackGrowsDown, Offset, MaxAlign, Skew); } // FIXME: Once this is working, then enable flag will change to a target @@ -642,7 +638,7 @@ void PEI::calculateFrameObjectOffsets(MachineFunction &Fn) { unsigned Align = MFI->getLocalFrameMaxAlign(); // Adjust to alignment boundary. - Offset = RoundUpToAlignment(Offset, Align); + Offset = RoundUpToAlignment(Offset, Align, Skew); DEBUG(dbgs() << "Local frame base offset: " << Offset << "\n"); @@ -669,7 +665,7 @@ void PEI::calculateFrameObjectOffsets(MachineFunction &Fn) { StackObjSet AddrOfObjs; AdjustStackOffset(MFI, MFI->getStackProtectorIndex(), StackGrowsDown, - Offset, MaxAlign); + Offset, MaxAlign, Skew); // Assign large stack objects first. for (unsigned i = 0, e = MFI->getObjectIndexEnd(); i != e; ++i) { @@ -702,11 +698,11 @@ void PEI::calculateFrameObjectOffsets(MachineFunction &Fn) { } AssignProtectedObjSet(LargeArrayObjs, ProtectedObjs, MFI, StackGrowsDown, - Offset, MaxAlign); + Offset, MaxAlign, Skew); AssignProtectedObjSet(SmallArrayObjs, ProtectedObjs, MFI, StackGrowsDown, - Offset, MaxAlign); + Offset, MaxAlign, Skew); AssignProtectedObjSet(AddrOfObjs, ProtectedObjs, MFI, StackGrowsDown, - Offset, MaxAlign); + Offset, MaxAlign, Skew); } // Then assign frame offsets to stack objects that are not used to spill @@ -726,7 +722,7 @@ void PEI::calculateFrameObjectOffsets(MachineFunction &Fn) { if (ProtectedObjs.count(i)) continue; - AdjustStackOffset(MFI, i, StackGrowsDown, Offset, MaxAlign); + AdjustStackOffset(MFI, i, StackGrowsDown, Offset, MaxAlign, Skew); } // Make sure the special register scavenging spill slot is closest to the @@ -736,7 +732,7 @@ void PEI::calculateFrameObjectOffsets(MachineFunction &Fn) { RS->getScavengingFrameIndices(SFIs); for (SmallVectorImpl::iterator I = SFIs.begin(), IE = SFIs.end(); I != IE; ++I) - AdjustStackOffset(MFI, *I, StackGrowsDown, Offset, MaxAlign); + AdjustStackOffset(MFI, *I, StackGrowsDown, Offset, MaxAlign, Skew); } if (!TFI.targetHandlesStackFrameRounding()) { @@ -761,7 +757,7 @@ void PEI::calculateFrameObjectOffsets(MachineFunction &Fn) { // If the frame pointer is eliminated, all frame offsets will be relative to // SP not FP. Align to MaxAlign so this works. StackAlign = std::max(StackAlign, MaxAlign); - Offset = RoundUpToAlignment(Offset, StackAlign); + Offset = RoundUpToAlignment(Offset, StackAlign, Skew); } // Update frame info to pretend that this is part of the stack... @@ -778,18 +774,24 @@ void PEI::insertPrologEpilogCode(MachineFunction &Fn) { const TargetFrameLowering &TFI = *Fn.getSubtarget().getFrameLowering(); // Add prologue to the function... - TFI.emitPrologue(Fn, *SaveBlock); + for (MachineBasicBlock *SaveBlock : SaveBlocks) + TFI.emitPrologue(Fn, *SaveBlock); // Add epilogue to restore the callee-save registers in each exiting block. for (MachineBasicBlock *RestoreBlock : RestoreBlocks) TFI.emitEpilogue(Fn, *RestoreBlock); + for (MachineBasicBlock *SaveBlock : SaveBlocks) + TFI.inlineStackProbe(Fn, *SaveBlock); + // Emit additional code that is required to support segmented stacks, if // we've been asked for it. This, when linked with a runtime with support // for segmented stacks (libgcc is one), will result in allocating stack // space in small chunks instead of one large contiguous block. - if (Fn.shouldSplitStack()) - TFI.adjustForSegmentedStacks(Fn, *SaveBlock); + if (Fn.shouldSplitStack()) { + for (MachineBasicBlock *SaveBlock : SaveBlocks) + TFI.adjustForSegmentedStacks(Fn, *SaveBlock); + } // Emit additional code that is required to explicitly handle the stack in // HiPE native code (if needed) when loaded in the Erlang/OTP runtime. The @@ -797,7 +799,8 @@ void PEI::insertPrologEpilogCode(MachineFunction &Fn) { // different conditional check and another BIF for allocating more stack // space. if (Fn.getFunction()->getCallingConv() == CallingConv::HiPE) - TFI.adjustForHiPEPrologue(Fn, *SaveBlock); + for (MachineBasicBlock *SaveBlock : SaveBlocks) + TFI.adjustForHiPEPrologue(Fn, *SaveBlock); } /// replaceFrameIndices - Replace all MO_FrameIndex operands with physical @@ -807,25 +810,6 @@ void PEI::replaceFrameIndices(MachineFunction &Fn) { const TargetFrameLowering &TFI = *Fn.getSubtarget().getFrameLowering(); if (!TFI.needsFrameIndexResolution(Fn)) return; - MachineModuleInfo &MMI = Fn.getMMI(); - const Function *F = Fn.getFunction(); - const Function *ParentF = MMI.getWinEHParent(F); - unsigned FrameReg; - if (F == ParentF) { - WinEHFuncInfo &FuncInfo = MMI.getWinEHFuncInfo(Fn.getFunction()); - // FIXME: This should be unconditional but we have bugs in the preparation - // pass. - if (FuncInfo.UnwindHelpFrameIdx != INT_MAX) - FuncInfo.UnwindHelpFrameOffset = TFI.getFrameIndexReferenceFromSP( - Fn, FuncInfo.UnwindHelpFrameIdx, FrameReg); - } else if (MMI.hasWinEHFuncInfo(F)) { - WinEHFuncInfo &FuncInfo = MMI.getWinEHFuncInfo(Fn.getFunction()); - auto I = FuncInfo.CatchHandlerParentFrameObjIdx.find(F); - if (I != FuncInfo.CatchHandlerParentFrameObjIdx.end()) - FuncInfo.CatchHandlerParentFrameObjOffset[F] = - TFI.getFrameIndexReferenceFromSP(Fn, I->second, FrameReg); - } - // Store SPAdj at exit of a basic block. SmallVector SPState; SPState.resize(Fn.getNumBlockIDs()); @@ -848,12 +832,12 @@ void PEI::replaceFrameIndices(MachineFunction &Fn) { } // Handle the unreachable blocks. - for (MachineFunction::iterator BB = Fn.begin(), E = Fn.end(); BB != E; ++BB) { - if (Reachable.count(BB)) + for (auto &BB : Fn) { + if (Reachable.count(&BB)) // Already handled in DFS traversal. continue; int SPAdj = 0; - replaceFrameIndices(BB, Fn, SPAdj); + replaceFrameIndices(&BB, Fn, SPAdj); } } @@ -864,8 +848,8 @@ void PEI::replaceFrameIndices(MachineBasicBlock *BB, MachineFunction &Fn, const TargetInstrInfo &TII = *Fn.getSubtarget().getInstrInfo(); const TargetRegisterInfo &TRI = *Fn.getSubtarget().getRegisterInfo(); const TargetFrameLowering *TFI = Fn.getSubtarget().getFrameLowering(); - int FrameSetupOpcode = TII.getCallFrameSetupOpcode(); - int FrameDestroyOpcode = TII.getCallFrameDestroyOpcode(); + unsigned FrameSetupOpcode = TII.getCallFrameSetupOpcode(); + unsigned FrameDestroyOpcode = TII.getCallFrameDestroyOpcode(); if (RS && !FrameIndexVirtualScavenging) RS->enterBasicBlock(BB); @@ -896,11 +880,11 @@ void PEI::replaceFrameIndices(MachineBasicBlock *BB, MachineFunction &Fn, if (!MI->getOperand(i).isFI()) continue; - // Frame indicies in debug values are encoded in a target independent + // Frame indices in debug values are encoded in a target independent // way with simply the frame index and offset rather than any // target-specific addressing mode. if (MI->isDebugValue()) { - assert(i == 0 && "Frame indicies can only appear as the first " + assert(i == 0 && "Frame indices can only appear as the first " "operand of a DBG_VALUE machine instruction"); unsigned Reg; MachineOperand &Offset = MI->getOperand(1); @@ -986,7 +970,7 @@ PEI::scavengeFrameVirtualRegs(MachineFunction &Fn) { // Run through the instructions and find any virtual registers. for (MachineFunction::iterator BB = Fn.begin(), E = Fn.end(); BB != E; ++BB) { - RS->enterBasicBlock(BB); + RS->enterBasicBlock(&*BB); int SPAdj = 0; @@ -1033,12 +1017,8 @@ PEI::scavengeFrameVirtualRegs(MachineFunction &Fn) { // Replace this reference to the virtual register with the // scratch register. assert (ScratchReg && "Missing scratch register!"); - MachineRegisterInfo &MRI = Fn.getRegInfo(); Fn.getRegInfo().replaceRegWith(Reg, ScratchReg); - // Make sure MRI now accounts this register as used. - MRI.setPhysRegUsed(ScratchReg); - // Because this instruction was processed by the RS before this // register was allocated, make sure that the RS now records the // register as being used. @@ -1051,7 +1031,7 @@ PEI::scavengeFrameVirtualRegs(MachineFunction &Fn) { // problem because we need the spill code before I: Move I to just // prior to J. if (I != std::prev(J)) { - BB->splice(J, BB, I); + BB->splice(J, &*BB, I); // Before we move I, we need to prepare the RS to visit I again. // Specifically, RS will assert if it sees uses of registers that