X-Git-Url: http://demsky.eecs.uci.edu/git/?a=blobdiff_plain;f=lib%2FCodeGen%2FPrologEpilogInserter.cpp;h=4b1e979a62cf6e7caa3f7d3144b3436cf6079d8e;hb=021e3b6444e9179751002db7b20de96455e03171;hp=ad7b6e4aa97f566cce11e3997202e353a707bac9;hpb=16c29b5f285f375be53dabaa73e3e91107485fe4;p=oota-llvm.git diff --git a/lib/CodeGen/PrologEpilogInserter.cpp b/lib/CodeGen/PrologEpilogInserter.cpp index ad7b6e4aa97..4b1e979a62c 100644 --- a/lib/CodeGen/PrologEpilogInserter.cpp +++ b/lib/CodeGen/PrologEpilogInserter.cpp @@ -21,44 +21,45 @@ #define DEBUG_TYPE "pei" #include "PrologEpilogInserter.h" -#include "llvm/InlineAsm.h" +#include "llvm/ADT/IndexedMap.h" +#include "llvm/ADT/STLExtras.h" +#include "llvm/ADT/SmallSet.h" +#include "llvm/ADT/Statistic.h" #include "llvm/CodeGen/MachineDominators.h" -#include "llvm/CodeGen/MachineLoopInfo.h" -#include "llvm/CodeGen/MachineInstr.h" #include "llvm/CodeGen/MachineFrameInfo.h" +#include "llvm/CodeGen/MachineInstr.h" +#include "llvm/CodeGen/MachineLoopInfo.h" #include "llvm/CodeGen/MachineRegisterInfo.h" #include "llvm/CodeGen/RegisterScavenging.h" -#include "llvm/Target/TargetMachine.h" -#include "llvm/Target/TargetRegisterInfo.h" -#include "llvm/Target/TargetFrameLowering.h" -#include "llvm/Target/TargetInstrInfo.h" +#include "llvm/InlineAsm.h" #include "llvm/Support/CommandLine.h" #include "llvm/Support/Compiler.h" #include "llvm/Support/Debug.h" -#include "llvm/ADT/IndexedMap.h" -#include "llvm/ADT/SmallSet.h" -#include "llvm/ADT/Statistic.h" -#include "llvm/ADT/STLExtras.h" +#include "llvm/Target/TargetFrameLowering.h" +#include "llvm/Target/TargetInstrInfo.h" +#include "llvm/Target/TargetMachine.h" +#include "llvm/Target/TargetOptions.h" +#include "llvm/Target/TargetRegisterInfo.h" #include using namespace llvm; char PEI::ID = 0; +char &llvm::PrologEpilogCodeInserterID = PEI::ID; INITIALIZE_PASS_BEGIN(PEI, "prologepilog", "Prologue/Epilogue Insertion", false, false) INITIALIZE_PASS_DEPENDENCY(MachineLoopInfo) INITIALIZE_PASS_DEPENDENCY(MachineDominatorTree) +INITIALIZE_PASS_DEPENDENCY(TargetPassConfig) INITIALIZE_PASS_END(PEI, "prologepilog", - "Prologue/Epilogue Insertion", false, false) + "Prologue/Epilogue Insertion & Frame Finalization", + false, false) STATISTIC(NumVirtualFrameRegs, "Number of virtual frame regs encountered"); STATISTIC(NumScavengedRegs, "Number of frame index regs scavenged"); - -/// createPrologEpilogCodeInserter - This function returns a pass that inserts -/// prolog and epilog code, and eliminates abstract frame references. -/// -FunctionPass *llvm::createPrologEpilogCodeInserter() { return new PEI(); } +STATISTIC(NumBytesStackSpace, + "Number of bytes used for stack in all functions"); /// runOnMachineFunction - Insert prolog/epilog code and replace abstract /// frame indexes with appropriate references. @@ -68,6 +69,8 @@ bool PEI::runOnMachineFunction(MachineFunction &Fn) { const TargetRegisterInfo *TRI = Fn.getTarget().getRegisterInfo(); const TargetFrameLowering *TFI = Fn.getTarget().getFrameLowering(); + assert(!Fn.getRegInfo().getNumVirtRegs() && "Regalloc must assign all vregs"); + RS = TRI->requiresRegisterScavenging(Fn) ? new RegScavenger() : NULL; FrameIndexVirtualScavenging = TRI->requiresFrameIndexScavenging(Fn); @@ -93,7 +96,7 @@ bool PEI::runOnMachineFunction(MachineFunction &Fn) { placeCSRSpillsAndRestores(Fn); // Add the code to save and restore the callee saved registers - if (!F->hasFnAttr(Attribute::Naked)) + if (!F->getFnAttributes().hasAttribute(Attribute::Naked)) insertCSRSpillsAndRestores(Fn); // Allow the target machine to make final modifications to the function @@ -108,7 +111,7 @@ bool PEI::runOnMachineFunction(MachineFunction &Fn) { // called functions. Because of this, calculateCalleeSavedRegisters() // must be called before this function in order to set the AdjustsStack // and MaxCallFrameSize variables. - if (!F->hasFnAttr(Attribute::Naked)) + if (!F->getFnAttributes().hasAttribute(Attribute::Naked)) insertPrologEpilogCode(Fn); // Replace all MO_FrameIndex operands with physical register references @@ -122,29 +125,20 @@ bool PEI::runOnMachineFunction(MachineFunction &Fn) { if (TRI->requiresRegisterScavenging(Fn) && FrameIndexVirtualScavenging) scavengeFrameVirtualRegs(Fn); + // Clear any vregs created by virtual scavenging. + Fn.getRegInfo().clearVirtRegs(); + delete RS; clearAllSets(); return true; } -#if 0 -void PEI::getAnalysisUsage(AnalysisUsage &AU) const { - AU.setPreservesCFG(); - if (ShrinkWrapping || ShrinkWrapFunc != "") { - AU.addRequired(); - AU.addRequired(); - } - AU.addPreserved(); - AU.addPreserved(); - MachineFunctionPass::getAnalysisUsage(AU); -} -#endif - /// calculateCallsInformation - Calculate the MaxCallFrameSize and AdjustsStack /// variables for the function's frame information and eliminate call frame /// pseudo instructions. void PEI::calculateCallsInformation(MachineFunction &Fn) { const TargetRegisterInfo *RegInfo = Fn.getTarget().getRegisterInfo(); + const TargetInstrInfo &TII = *Fn.getTarget().getInstrInfo(); const TargetFrameLowering *TFI = Fn.getTarget().getFrameLowering(); MachineFrameInfo *MFI = Fn.getFrameInfo(); @@ -152,8 +146,8 @@ void PEI::calculateCallsInformation(MachineFunction &Fn) { bool AdjustsStack = MFI->adjustsStack(); // Get the function call frame set-up and tear-down instruction opcode - int FrameSetupOpcode = RegInfo->getCallFrameSetupOpcode(); - int FrameDestroyOpcode = RegInfo->getCallFrameDestroyOpcode(); + int FrameSetupOpcode = TII.getCallFrameSetupOpcode(); + int FrameDestroyOpcode = TII.getCallFrameDestroyOpcode(); // Early exit for targets which have no call frame setup/destroy pseudo // instructions. @@ -203,7 +197,7 @@ void PEI::calculateCalleeSavedRegisters(MachineFunction &Fn) { MachineFrameInfo *MFI = Fn.getFrameInfo(); // Get the callee saved register list... - const unsigned *CSRegs = RegInfo->getCalleeSavedRegs(&Fn); + const uint16_t *CSRegs = RegInfo->getCalleeSavedRegs(&Fn); // These are used to keep track the callee-save area. Initialize them. MinCSFrameIndex = INT_MAX; @@ -214,7 +208,7 @@ void PEI::calculateCalleeSavedRegisters(MachineFunction &Fn) { return; // In Naked functions we aren't going to save any registers. - if (Fn.getFunction()->hasFnAttr(Attribute::Naked)) + if (Fn.getFunction()->getFnAttributes().hasAttribute(Attribute::Naked)) return; std::vector CSI; @@ -223,14 +217,6 @@ void PEI::calculateCalleeSavedRegisters(MachineFunction &Fn) { if (Fn.getRegInfo().isPhysRegUsed(Reg)) { // If the reg is modified, save it! CSI.push_back(CalleeSavedInfo(Reg)); - } else { - for (const unsigned *AliasSet = RegInfo->getAliasSet(Reg); - *AliasSet; ++AliasSet) { // Check alias registers too. - if (Fn.getRegInfo().isPhysRegUsed(*AliasSet)) { - CSI.push_back(CalleeSavedInfo(Reg)); - break; - } - } } } @@ -303,7 +289,7 @@ void PEI::insertCSRSpillsAndRestores(MachineFunction &Fn) { const TargetRegisterInfo *TRI = Fn.getTarget().getRegisterInfo(); MachineBasicBlock::iterator I; - if (! ShrinkWrapThisFunction) { + if (!ShrinkWrapThisFunction) { // Spill using target interface. I = EntryBlock->begin(); if (!TFI->spillCalleeSavedRegisters(*EntryBlock, I, CSI, TRI)) { @@ -328,7 +314,7 @@ void PEI::insertCSRSpillsAndRestores(MachineFunction &Fn) { // Skip over all terminator instructions, which are part of the return // sequence. MachineBasicBlock::iterator I2 = I; - while (I2 != MBB->begin() && (--I2)->getDesc().isTerminator()) + while (I2 != MBB->begin() && (--I2)->isTerminator()) I = I2; bool AtStart = I == MBB->begin(); @@ -337,7 +323,7 @@ void PEI::insertCSRSpillsAndRestores(MachineFunction &Fn) { --BeforeI; // Restore all registers immediately before the return and any - // terminators that preceed it. + // terminators that precede it. if (!TFI->restoreCalleeSavedRegisters(*MBB, I, CSI, TRI)) { for (unsigned i = 0, e = CSI.size(); i != e; ++i) { unsigned Reg = CSI[i].getReg(); @@ -422,11 +408,11 @@ void PEI::insertCSRSpillsAndRestores(MachineFunction &Fn) { // Skip over all terminator instructions, which are part of the // return sequence. - if (! I->getDesc().isTerminator()) { + if (! I->isTerminator()) { ++I; } else { MachineBasicBlock::iterator I2 = I; - while (I2 != MBB->begin() && (--I2)->getDesc().isTerminator()) + while (I2 != MBB->begin() && (--I2)->isTerminator()) I = I2; } } @@ -437,7 +423,7 @@ void PEI::insertCSRSpillsAndRestores(MachineFunction &Fn) { --BeforeI; // Restore all registers immediately before the return and any - // terminators that preceed it. + // terminators that precede it. for (unsigned i = 0, e = blockCSI.size(); i != e; ++i) { unsigned Reg = blockCSI[i].getReg(); const TargetRegisterClass *RC = TRI->getMinimalPhysRegClass(Reg); @@ -559,7 +545,8 @@ void PEI::calculateFrameObjectOffsets(MachineFunction &Fn) { // Make sure the special register scavenging spill slot is closest to the // frame pointer if a frame pointer is required. const TargetRegisterInfo *RegInfo = Fn.getTarget().getRegisterInfo(); - if (RS && TFI.hasFP(Fn) && !RegInfo->needsStackRealignment(Fn)) { + if (RS && TFI.hasFP(Fn) && RegInfo->useFPForScavengingIndex(Fn) && + !RegInfo->needsStackRealignment(Fn)) { int SFI = RS->getScavengingFrameIndex(); if (SFI >= 0) AdjustStackOffset(MFI, SFI, StackGrowsDown, Offset, MaxAlign); @@ -641,7 +628,8 @@ void PEI::calculateFrameObjectOffsets(MachineFunction &Fn) { // Make sure the special register scavenging spill slot is closest to the // stack pointer. - if (RS && (!TFI.hasFP(Fn) || RegInfo->needsStackRealignment(Fn))) { + if (RS && (!TFI.hasFP(Fn) || RegInfo->needsStackRealignment(Fn) || + !RegInfo->useFPForScavengingIndex(Fn))) { int SFI = RS->getScavengingFrameIndex(); if (SFI >= 0) AdjustStackOffset(MFI, SFI, StackGrowsDown, Offset, MaxAlign); @@ -674,7 +662,9 @@ void PEI::calculateFrameObjectOffsets(MachineFunction &Fn) { } // Update frame info to pretend that this is part of the stack... - MFI->setStackSize(Offset - LocalAreaOffset); + int64_t StackSize = Offset - LocalAreaOffset; + MFI->setStackSize(StackSize); + NumBytesStackSpace += StackSize; } /// insertPrologEpilogCode - Scan the function for modified callee saved @@ -690,9 +680,16 @@ void PEI::insertPrologEpilogCode(MachineFunction &Fn) { // Add epilogue to restore the callee-save registers in each exiting block for (MachineFunction::iterator I = Fn.begin(), E = Fn.end(); I != E; ++I) { // If last instruction is a return instruction, add an epilogue - if (!I->empty() && I->back().getDesc().isReturn()) + if (!I->empty() && I->back().isReturn()) TFI.emitEpilogue(Fn, *I); } + + // 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.getTarget().Options.EnableSegmentedStacks) + TFI.adjustForSegmentedStacks(Fn); } /// replaceFrameIndices - Replace all MO_FrameIndex operands with physical @@ -703,12 +700,13 @@ void PEI::replaceFrameIndices(MachineFunction &Fn) { const TargetMachine &TM = Fn.getTarget(); assert(TM.getRegisterInfo() && "TM::getRegisterInfo() must be implemented!"); + const TargetInstrInfo &TII = *Fn.getTarget().getInstrInfo(); const TargetRegisterInfo &TRI = *TM.getRegisterInfo(); const TargetFrameLowering *TFI = TM.getFrameLowering(); bool StackGrowsDown = TFI->getStackGrowthDirection() == TargetFrameLowering::StackGrowsDown; - int FrameSetupOpcode = TRI.getCallFrameSetupOpcode(); - int FrameDestroyOpcode = TRI.getCallFrameDestroyOpcode(); + int FrameSetupOpcode = TII.getCallFrameSetupOpcode(); + int FrameDestroyOpcode = TII.getCallFrameDestroyOpcode(); for (MachineFunction::iterator BB = Fn.begin(), E = Fn.end(); BB != E; ++BB) { @@ -797,6 +795,10 @@ void PEI::replaceFrameIndices(MachineFunction &Fn) { /// scavengeFrameVirtualRegs - Replace all frame index virtual registers /// with physical registers. Use the register scavenger to find an /// appropriate register to use. +/// +/// FIXME: Iterating over the instruction stream is unnecessary. We can simply +/// iterate over the vreg use list, which at this point only contains machine +/// operands for which eliminateFrameIndex need a new scratch reg. void PEI::scavengeFrameVirtualRegs(MachineFunction &Fn) { // Run through the instructions and find any virtual registers. for (MachineFunction::iterator BB = Fn.begin(), @@ -811,7 +813,6 @@ void PEI::scavengeFrameVirtualRegs(MachineFunction &Fn) { // directly. for (MachineBasicBlock::iterator I = BB->begin(); I != BB->end(); ) { MachineInstr *MI = I; - bool DoIncr = true; for (unsigned i = 0, e = MI->getNumOperands(); i != e; ++i) { if (MI->getOperand(i).isReg()) { MachineOperand &MO = MI->getOperand(i); @@ -842,10 +843,8 @@ void PEI::scavengeFrameVirtualRegs(MachineFunction &Fn) { } } - if (DoIncr) { - RS->forward(I); - ++I; - } + RS->forward(I); + ++I; } } }