Rename TargetFrameInfo into TargetFrameLowering. Also, put couple of FIXMEs and fixes here and there.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@123170 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Target/PowerPC/PPCFrameLowering.cpp b/lib/Target/PowerPC/PPCFrameLowering.cpp
new file mode 100644
index 0000000..4c5b94d
--- /dev/null
+++ b/lib/Target/PowerPC/PPCFrameLowering.cpp
@@ -0,0 +1,970 @@
+//=====- PPCFrameLowering.cpp - PPC Frame Information -----------*- C++ -*-===//
+//
+// The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file contains the PPC implementation of TargetFrameLowering class.
+//
+//===----------------------------------------------------------------------===//
+
+#include "PPCFrameLowering.h"
+#include "PPCInstrInfo.h"
+#include "PPCMachineFunctionInfo.h"
+#include "llvm/Function.h"
+#include "llvm/CodeGen/MachineFrameInfo.h"
+#include "llvm/CodeGen/MachineFunction.h"
+#include "llvm/CodeGen/MachineInstrBuilder.h"
+#include "llvm/CodeGen/MachineModuleInfo.h"
+#include "llvm/CodeGen/MachineRegisterInfo.h"
+#include "llvm/CodeGen/RegisterScavenging.h"
+#include "llvm/Target/TargetOptions.h"
+
+using namespace llvm;
+
+// FIXME This disables some code that aligns the stack to a boundary bigger than
+// the default (16 bytes on Darwin) when there is a stack local of greater
+// alignment. This does not currently work, because the delta between old and
+// new stack pointers is added to offsets that reference incoming parameters
+// after the prolog is generated, and the code that does that doesn't handle a
+// variable delta. You don't want to do that anyway; a better approach is to
+// reserve another register that retains to the incoming stack pointer, and
+// reference parameters relative to that.
+#define ALIGN_STACK 0
+
+
+/// VRRegNo - Map from a numbered VR register to its enum value.
+///
+static const unsigned short VRRegNo[] = {
+ PPC::V0 , PPC::V1 , PPC::V2 , PPC::V3 , PPC::V4 , PPC::V5 , PPC::V6 , PPC::V7 ,
+ PPC::V8 , PPC::V9 , PPC::V10, PPC::V11, PPC::V12, PPC::V13, PPC::V14, PPC::V15,
+ PPC::V16, PPC::V17, PPC::V18, PPC::V19, PPC::V20, PPC::V21, PPC::V22, PPC::V23,
+ PPC::V24, PPC::V25, PPC::V26, PPC::V27, PPC::V28, PPC::V29, PPC::V30, PPC::V31
+};
+
+/// RemoveVRSaveCode - We have found that this function does not need any code
+/// to manipulate the VRSAVE register, even though it uses vector registers.
+/// This can happen when the only registers used are known to be live in or out
+/// of the function. Remove all of the VRSAVE related code from the function.
+static void RemoveVRSaveCode(MachineInstr *MI) {
+ MachineBasicBlock *Entry = MI->getParent();
+ MachineFunction *MF = Entry->getParent();
+
+ // We know that the MTVRSAVE instruction immediately follows MI. Remove it.
+ MachineBasicBlock::iterator MBBI = MI;
+ ++MBBI;
+ assert(MBBI != Entry->end() && MBBI->getOpcode() == PPC::MTVRSAVE);
+ MBBI->eraseFromParent();
+
+ bool RemovedAllMTVRSAVEs = true;
+ // See if we can find and remove the MTVRSAVE instruction from all of the
+ // epilog blocks.
+ for (MachineFunction::iterator I = MF->begin(), E = MF->end(); I != E; ++I) {
+ // If last instruction is a return instruction, add an epilogue
+ if (!I->empty() && I->back().getDesc().isReturn()) {
+ bool FoundIt = false;
+ for (MBBI = I->end(); MBBI != I->begin(); ) {
+ --MBBI;
+ if (MBBI->getOpcode() == PPC::MTVRSAVE) {
+ MBBI->eraseFromParent(); // remove it.
+ FoundIt = true;
+ break;
+ }
+ }
+ RemovedAllMTVRSAVEs &= FoundIt;
+ }
+ }
+
+ // If we found and removed all MTVRSAVE instructions, remove the read of
+ // VRSAVE as well.
+ if (RemovedAllMTVRSAVEs) {
+ MBBI = MI;
+ assert(MBBI != Entry->begin() && "UPDATE_VRSAVE is first instr in block?");
+ --MBBI;
+ assert(MBBI->getOpcode() == PPC::MFVRSAVE && "VRSAVE instrs wandered?");
+ MBBI->eraseFromParent();
+ }
+
+ // Finally, nuke the UPDATE_VRSAVE.
+ MI->eraseFromParent();
+}
+
+// HandleVRSaveUpdate - MI is the UPDATE_VRSAVE instruction introduced by the
+// instruction selector. Based on the vector registers that have been used,
+// transform this into the appropriate ORI instruction.
+static void HandleVRSaveUpdate(MachineInstr *MI, const TargetInstrInfo &TII) {
+ MachineFunction *MF = MI->getParent()->getParent();
+ DebugLoc dl = MI->getDebugLoc();
+
+ unsigned UsedRegMask = 0;
+ for (unsigned i = 0; i != 32; ++i)
+ if (MF->getRegInfo().isPhysRegUsed(VRRegNo[i]))
+ UsedRegMask |= 1 << (31-i);
+
+ // Live in and live out values already must be in the mask, so don't bother
+ // marking them.
+ for (MachineRegisterInfo::livein_iterator
+ I = MF->getRegInfo().livein_begin(),
+ E = MF->getRegInfo().livein_end(); I != E; ++I) {
+ unsigned RegNo = PPCRegisterInfo::getRegisterNumbering(I->first);
+ if (VRRegNo[RegNo] == I->first) // If this really is a vector reg.
+ UsedRegMask &= ~(1 << (31-RegNo)); // Doesn't need to be marked.
+ }
+ for (MachineRegisterInfo::liveout_iterator
+ I = MF->getRegInfo().liveout_begin(),
+ E = MF->getRegInfo().liveout_end(); I != E; ++I) {
+ unsigned RegNo = PPCRegisterInfo::getRegisterNumbering(*I);
+ if (VRRegNo[RegNo] == *I) // If this really is a vector reg.
+ UsedRegMask &= ~(1 << (31-RegNo)); // Doesn't need to be marked.
+ }
+
+ // If no registers are used, turn this into a copy.
+ if (UsedRegMask == 0) {
+ // Remove all VRSAVE code.
+ RemoveVRSaveCode(MI);
+ return;
+ }
+
+ unsigned SrcReg = MI->getOperand(1).getReg();
+ unsigned DstReg = MI->getOperand(0).getReg();
+
+ if ((UsedRegMask & 0xFFFF) == UsedRegMask) {
+ if (DstReg != SrcReg)
+ BuildMI(*MI->getParent(), MI, dl, TII.get(PPC::ORI), DstReg)
+ .addReg(SrcReg)
+ .addImm(UsedRegMask);
+ else
+ BuildMI(*MI->getParent(), MI, dl, TII.get(PPC::ORI), DstReg)
+ .addReg(SrcReg, RegState::Kill)
+ .addImm(UsedRegMask);
+ } else if ((UsedRegMask & 0xFFFF0000) == UsedRegMask) {
+ if (DstReg != SrcReg)
+ BuildMI(*MI->getParent(), MI, dl, TII.get(PPC::ORIS), DstReg)
+ .addReg(SrcReg)
+ .addImm(UsedRegMask >> 16);
+ else
+ BuildMI(*MI->getParent(), MI, dl, TII.get(PPC::ORIS), DstReg)
+ .addReg(SrcReg, RegState::Kill)
+ .addImm(UsedRegMask >> 16);
+ } else {
+ if (DstReg != SrcReg)
+ BuildMI(*MI->getParent(), MI, dl, TII.get(PPC::ORIS), DstReg)
+ .addReg(SrcReg)
+ .addImm(UsedRegMask >> 16);
+ else
+ BuildMI(*MI->getParent(), MI, dl, TII.get(PPC::ORIS), DstReg)
+ .addReg(SrcReg, RegState::Kill)
+ .addImm(UsedRegMask >> 16);
+
+ BuildMI(*MI->getParent(), MI, dl, TII.get(PPC::ORI), DstReg)
+ .addReg(DstReg, RegState::Kill)
+ .addImm(UsedRegMask & 0xFFFF);
+ }
+
+ // Remove the old UPDATE_VRSAVE instruction.
+ MI->eraseFromParent();
+}
+
+/// determineFrameLayout - Determine the size of the frame and maximum call
+/// frame size.
+void PPCFrameLowering::determineFrameLayout(MachineFunction &MF) const {
+ MachineFrameInfo *MFI = MF.getFrameInfo();
+
+ // Get the number of bytes to allocate from the FrameInfo
+ unsigned FrameSize = MFI->getStackSize();
+
+ // Get the alignments provided by the target, and the maximum alignment
+ // (if any) of the fixed frame objects.
+ unsigned MaxAlign = MFI->getMaxAlignment();
+ unsigned TargetAlign = getStackAlignment();
+ unsigned AlignMask = TargetAlign - 1; //
+
+ // If we are a leaf function, and use up to 224 bytes of stack space,
+ // don't have a frame pointer, calls, or dynamic alloca then we do not need
+ // to adjust the stack pointer (we fit in the Red Zone).
+ bool DisableRedZone = MF.getFunction()->hasFnAttr(Attribute::NoRedZone);
+ // FIXME SVR4 The 32-bit SVR4 ABI has no red zone.
+ if (!DisableRedZone &&
+ FrameSize <= 224 && // Fits in red zone.
+ !MFI->hasVarSizedObjects() && // No dynamic alloca.
+ !MFI->adjustsStack() && // No calls.
+ (!ALIGN_STACK || MaxAlign <= TargetAlign)) { // No special alignment.
+ // No need for frame
+ MFI->setStackSize(0);
+ return;
+ }
+
+ // Get the maximum call frame size of all the calls.
+ unsigned maxCallFrameSize = MFI->getMaxCallFrameSize();
+
+ // Maximum call frame needs to be at least big enough for linkage and 8 args.
+ unsigned minCallFrameSize = getMinCallFrameSize(Subtarget.isPPC64(),
+ Subtarget.isDarwinABI());
+ maxCallFrameSize = std::max(maxCallFrameSize, minCallFrameSize);
+
+ // If we have dynamic alloca then maxCallFrameSize needs to be aligned so
+ // that allocations will be aligned.
+ if (MFI->hasVarSizedObjects())
+ maxCallFrameSize = (maxCallFrameSize + AlignMask) & ~AlignMask;
+
+ // Update maximum call frame size.
+ MFI->setMaxCallFrameSize(maxCallFrameSize);
+
+ // Include call frame size in total.
+ FrameSize += maxCallFrameSize;
+
+ // Make sure the frame is aligned.
+ FrameSize = (FrameSize + AlignMask) & ~AlignMask;
+
+ // Update frame info.
+ MFI->setStackSize(FrameSize);
+}
+
+// hasFP - Return true if the specified function actually has a dedicated frame
+// pointer register.
+bool PPCFrameLowering::hasFP(const MachineFunction &MF) const {
+ const MachineFrameInfo *MFI = MF.getFrameInfo();
+ // FIXME: This is pretty much broken by design: hasFP() might be called really
+ // early, before the stack layout was calculated and thus hasFP() might return
+ // true or false here depending on the time of call.
+ return (MFI->getStackSize()) && needsFP(MF);
+}
+
+// needsFP - Return true if the specified function should have a dedicated frame
+// pointer register. This is true if the function has variable sized allocas or
+// if frame pointer elimination is disabled.
+bool PPCFrameLowering::needsFP(const MachineFunction &MF) const {
+ const MachineFrameInfo *MFI = MF.getFrameInfo();
+
+ // Naked functions have no stack frame pushed, so we don't have a frame
+ // pointer.
+ if (MF.getFunction()->hasFnAttr(Attribute::Naked))
+ return false;
+
+ return DisableFramePointerElim(MF) || MFI->hasVarSizedObjects() ||
+ (GuaranteedTailCallOpt && MF.getInfo<PPCFunctionInfo>()->hasFastCall());
+}
+
+
+void PPCFrameLowering::emitPrologue(MachineFunction &MF) const {
+ MachineBasicBlock &MBB = MF.front(); // Prolog goes in entry BB
+ MachineBasicBlock::iterator MBBI = MBB.begin();
+ MachineFrameInfo *MFI = MF.getFrameInfo();
+ const PPCInstrInfo &TII =
+ *static_cast<const PPCInstrInfo*>(MF.getTarget().getInstrInfo());
+
+ MachineModuleInfo &MMI = MF.getMMI();
+ DebugLoc dl;
+ bool needsFrameMoves = MMI.hasDebugInfo() ||
+ !MF.getFunction()->doesNotThrow() ||
+ UnwindTablesMandatory;
+
+ // Prepare for frame info.
+ MCSymbol *FrameLabel = 0;
+
+ // Scan the prolog, looking for an UPDATE_VRSAVE instruction. If we find it,
+ // process it.
+ for (unsigned i = 0; MBBI != MBB.end(); ++i, ++MBBI) {
+ if (MBBI->getOpcode() == PPC::UPDATE_VRSAVE) {
+ HandleVRSaveUpdate(MBBI, TII);
+ break;
+ }
+ }
+
+ // Move MBBI back to the beginning of the function.
+ MBBI = MBB.begin();
+
+ // Work out frame sizes.
+ // FIXME: determineFrameLayout() may change the frame size. This should be
+ // moved upper, to some hook.
+ determineFrameLayout(MF);
+ unsigned FrameSize = MFI->getStackSize();
+
+ int NegFrameSize = -FrameSize;
+
+ // Get processor type.
+ bool isPPC64 = Subtarget.isPPC64();
+ // Get operating system
+ bool isDarwinABI = Subtarget.isDarwinABI();
+ // Check if the link register (LR) must be saved.
+ PPCFunctionInfo *FI = MF.getInfo<PPCFunctionInfo>();
+ bool MustSaveLR = FI->mustSaveLR();
+ // Do we have a frame pointer for this function?
+ bool HasFP = hasFP(MF);
+
+ int LROffset = PPCFrameLowering::getReturnSaveOffset(isPPC64, isDarwinABI);
+
+ int FPOffset = 0;
+ if (HasFP) {
+ if (Subtarget.isSVR4ABI()) {
+ MachineFrameInfo *FFI = MF.getFrameInfo();
+ int FPIndex = FI->getFramePointerSaveIndex();
+ assert(FPIndex && "No Frame Pointer Save Slot!");
+ FPOffset = FFI->getObjectOffset(FPIndex);
+ } else {
+ FPOffset = PPCFrameLowering::getFramePointerSaveOffset(isPPC64, isDarwinABI);
+ }
+ }
+
+ if (isPPC64) {
+ if (MustSaveLR)
+ BuildMI(MBB, MBBI, dl, TII.get(PPC::MFLR8), PPC::X0);
+
+ if (HasFP)
+ BuildMI(MBB, MBBI, dl, TII.get(PPC::STD))
+ .addReg(PPC::X31)
+ .addImm(FPOffset/4)
+ .addReg(PPC::X1);
+
+ if (MustSaveLR)
+ BuildMI(MBB, MBBI, dl, TII.get(PPC::STD))
+ .addReg(PPC::X0)
+ .addImm(LROffset / 4)
+ .addReg(PPC::X1);
+ } else {
+ if (MustSaveLR)
+ BuildMI(MBB, MBBI, dl, TII.get(PPC::MFLR), PPC::R0);
+
+ if (HasFP)
+ BuildMI(MBB, MBBI, dl, TII.get(PPC::STW))
+ .addReg(PPC::R31)
+ .addImm(FPOffset)
+ .addReg(PPC::R1);
+
+ if (MustSaveLR)
+ BuildMI(MBB, MBBI, dl, TII.get(PPC::STW))
+ .addReg(PPC::R0)
+ .addImm(LROffset)
+ .addReg(PPC::R1);
+ }
+
+ // Skip if a leaf routine.
+ if (!FrameSize) return;
+
+ // Get stack alignments.
+ unsigned TargetAlign = getStackAlignment();
+ unsigned MaxAlign = MFI->getMaxAlignment();
+
+ // Adjust stack pointer: r1 += NegFrameSize.
+ // If there is a preferred stack alignment, align R1 now
+ if (!isPPC64) {
+ // PPC32.
+ if (ALIGN_STACK && MaxAlign > TargetAlign) {
+ assert(isPowerOf2_32(MaxAlign) && isInt<16>(MaxAlign) &&
+ "Invalid alignment!");
+ assert(isInt<16>(NegFrameSize) && "Unhandled stack size and alignment!");
+
+ BuildMI(MBB, MBBI, dl, TII.get(PPC::RLWINM), PPC::R0)
+ .addReg(PPC::R1)
+ .addImm(0)
+ .addImm(32 - Log2_32(MaxAlign))
+ .addImm(31);
+ BuildMI(MBB, MBBI, dl, TII.get(PPC::SUBFIC) ,PPC::R0)
+ .addReg(PPC::R0, RegState::Kill)
+ .addImm(NegFrameSize);
+ BuildMI(MBB, MBBI, dl, TII.get(PPC::STWUX))
+ .addReg(PPC::R1)
+ .addReg(PPC::R1)
+ .addReg(PPC::R0);
+ } else if (isInt<16>(NegFrameSize)) {
+ BuildMI(MBB, MBBI, dl, TII.get(PPC::STWU), PPC::R1)
+ .addReg(PPC::R1)
+ .addImm(NegFrameSize)
+ .addReg(PPC::R1);
+ } else {
+ BuildMI(MBB, MBBI, dl, TII.get(PPC::LIS), PPC::R0)
+ .addImm(NegFrameSize >> 16);
+ BuildMI(MBB, MBBI, dl, TII.get(PPC::ORI), PPC::R0)
+ .addReg(PPC::R0, RegState::Kill)
+ .addImm(NegFrameSize & 0xFFFF);
+ BuildMI(MBB, MBBI, dl, TII.get(PPC::STWUX))
+ .addReg(PPC::R1)
+ .addReg(PPC::R1)
+ .addReg(PPC::R0);
+ }
+ } else { // PPC64.
+ if (ALIGN_STACK && MaxAlign > TargetAlign) {
+ assert(isPowerOf2_32(MaxAlign) && isInt<16>(MaxAlign) &&
+ "Invalid alignment!");
+ assert(isInt<16>(NegFrameSize) && "Unhandled stack size and alignment!");
+
+ BuildMI(MBB, MBBI, dl, TII.get(PPC::RLDICL), PPC::X0)
+ .addReg(PPC::X1)
+ .addImm(0)
+ .addImm(64 - Log2_32(MaxAlign));
+ BuildMI(MBB, MBBI, dl, TII.get(PPC::SUBFIC8), PPC::X0)
+ .addReg(PPC::X0)
+ .addImm(NegFrameSize);
+ BuildMI(MBB, MBBI, dl, TII.get(PPC::STDUX))
+ .addReg(PPC::X1)
+ .addReg(PPC::X1)
+ .addReg(PPC::X0);
+ } else if (isInt<16>(NegFrameSize)) {
+ BuildMI(MBB, MBBI, dl, TII.get(PPC::STDU), PPC::X1)
+ .addReg(PPC::X1)
+ .addImm(NegFrameSize / 4)
+ .addReg(PPC::X1);
+ } else {
+ BuildMI(MBB, MBBI, dl, TII.get(PPC::LIS8), PPC::X0)
+ .addImm(NegFrameSize >> 16);
+ BuildMI(MBB, MBBI, dl, TII.get(PPC::ORI8), PPC::X0)
+ .addReg(PPC::X0, RegState::Kill)
+ .addImm(NegFrameSize & 0xFFFF);
+ BuildMI(MBB, MBBI, dl, TII.get(PPC::STDUX))
+ .addReg(PPC::X1)
+ .addReg(PPC::X1)
+ .addReg(PPC::X0);
+ }
+ }
+
+ std::vector<MachineMove> &Moves = MMI.getFrameMoves();
+
+ // Add the "machine moves" for the instructions we generated above, but in
+ // reverse order.
+ if (needsFrameMoves) {
+ // Mark effective beginning of when frame pointer becomes valid.
+ FrameLabel = MMI.getContext().CreateTempSymbol();
+ BuildMI(MBB, MBBI, dl, TII.get(PPC::PROLOG_LABEL)).addSym(FrameLabel);
+
+ // Show update of SP.
+ if (NegFrameSize) {
+ MachineLocation SPDst(MachineLocation::VirtualFP);
+ MachineLocation SPSrc(MachineLocation::VirtualFP, NegFrameSize);
+ Moves.push_back(MachineMove(FrameLabel, SPDst, SPSrc));
+ } else {
+ MachineLocation SP(isPPC64 ? PPC::X31 : PPC::R31);
+ Moves.push_back(MachineMove(FrameLabel, SP, SP));
+ }
+
+ if (HasFP) {
+ MachineLocation FPDst(MachineLocation::VirtualFP, FPOffset);
+ MachineLocation FPSrc(isPPC64 ? PPC::X31 : PPC::R31);
+ Moves.push_back(MachineMove(FrameLabel, FPDst, FPSrc));
+ }
+
+ if (MustSaveLR) {
+ MachineLocation LRDst(MachineLocation::VirtualFP, LROffset);
+ MachineLocation LRSrc(isPPC64 ? PPC::LR8 : PPC::LR);
+ Moves.push_back(MachineMove(FrameLabel, LRDst, LRSrc));
+ }
+ }
+
+ MCSymbol *ReadyLabel = 0;
+
+ // If there is a frame pointer, copy R1 into R31
+ if (HasFP) {
+ if (!isPPC64) {
+ BuildMI(MBB, MBBI, dl, TII.get(PPC::OR), PPC::R31)
+ .addReg(PPC::R1)
+ .addReg(PPC::R1);
+ } else {
+ BuildMI(MBB, MBBI, dl, TII.get(PPC::OR8), PPC::X31)
+ .addReg(PPC::X1)
+ .addReg(PPC::X1);
+ }
+
+ if (needsFrameMoves) {
+ ReadyLabel = MMI.getContext().CreateTempSymbol();
+
+ // Mark effective beginning of when frame pointer is ready.
+ BuildMI(MBB, MBBI, dl, TII.get(PPC::PROLOG_LABEL)).addSym(ReadyLabel);
+
+ MachineLocation FPDst(HasFP ? (isPPC64 ? PPC::X31 : PPC::R31) :
+ (isPPC64 ? PPC::X1 : PPC::R1));
+ MachineLocation FPSrc(MachineLocation::VirtualFP);
+ Moves.push_back(MachineMove(ReadyLabel, FPDst, FPSrc));
+ }
+ }
+
+ if (needsFrameMoves) {
+ MCSymbol *Label = HasFP ? ReadyLabel : FrameLabel;
+
+ // Add callee saved registers to move list.
+ const std::vector<CalleeSavedInfo> &CSI = MFI->getCalleeSavedInfo();
+ for (unsigned I = 0, E = CSI.size(); I != E; ++I) {
+ int Offset = MFI->getObjectOffset(CSI[I].getFrameIdx());
+ unsigned Reg = CSI[I].getReg();
+ if (Reg == PPC::LR || Reg == PPC::LR8 || Reg == PPC::RM) continue;
+ MachineLocation CSDst(MachineLocation::VirtualFP, Offset);
+ MachineLocation CSSrc(Reg);
+ Moves.push_back(MachineMove(Label, CSDst, CSSrc));
+ }
+ }
+}
+
+void PPCFrameLowering::emitEpilogue(MachineFunction &MF,
+ MachineBasicBlock &MBB) const {
+ MachineBasicBlock::iterator MBBI = prior(MBB.end());
+ const PPCInstrInfo &TII =
+ *static_cast<const PPCInstrInfo*>(MF.getTarget().getInstrInfo());
+
+ unsigned RetOpcode = MBBI->getOpcode();
+ DebugLoc dl;
+
+ assert((RetOpcode == PPC::BLR ||
+ RetOpcode == PPC::TCRETURNri ||
+ RetOpcode == PPC::TCRETURNdi ||
+ RetOpcode == PPC::TCRETURNai ||
+ RetOpcode == PPC::TCRETURNri8 ||
+ RetOpcode == PPC::TCRETURNdi8 ||
+ RetOpcode == PPC::TCRETURNai8) &&
+ "Can only insert epilog into returning blocks");
+
+ // Get alignment info so we know how to restore r1
+ const MachineFrameInfo *MFI = MF.getFrameInfo();
+ unsigned TargetAlign = getStackAlignment();
+ unsigned MaxAlign = MFI->getMaxAlignment();
+
+ // Get the number of bytes allocated from the FrameInfo.
+ int FrameSize = MFI->getStackSize();
+
+ // Get processor type.
+ bool isPPC64 = Subtarget.isPPC64();
+ // Get operating system
+ bool isDarwinABI = Subtarget.isDarwinABI();
+ // Check if the link register (LR) has been saved.
+ PPCFunctionInfo *FI = MF.getInfo<PPCFunctionInfo>();
+ bool MustSaveLR = FI->mustSaveLR();
+ // Do we have a frame pointer for this function?
+ bool HasFP = hasFP(MF);
+
+ int LROffset = PPCFrameLowering::getReturnSaveOffset(isPPC64, isDarwinABI);
+
+ int FPOffset = 0;
+ if (HasFP) {
+ if (Subtarget.isSVR4ABI()) {
+ MachineFrameInfo *FFI = MF.getFrameInfo();
+ int FPIndex = FI->getFramePointerSaveIndex();
+ assert(FPIndex && "No Frame Pointer Save Slot!");
+ FPOffset = FFI->getObjectOffset(FPIndex);
+ } else {
+ FPOffset = PPCFrameLowering::getFramePointerSaveOffset(isPPC64, isDarwinABI);
+ }
+ }
+
+ bool UsesTCRet = RetOpcode == PPC::TCRETURNri ||
+ RetOpcode == PPC::TCRETURNdi ||
+ RetOpcode == PPC::TCRETURNai ||
+ RetOpcode == PPC::TCRETURNri8 ||
+ RetOpcode == PPC::TCRETURNdi8 ||
+ RetOpcode == PPC::TCRETURNai8;
+
+ if (UsesTCRet) {
+ int MaxTCRetDelta = FI->getTailCallSPDelta();
+ MachineOperand &StackAdjust = MBBI->getOperand(1);
+ assert(StackAdjust.isImm() && "Expecting immediate value.");
+ // Adjust stack pointer.
+ int StackAdj = StackAdjust.getImm();
+ int Delta = StackAdj - MaxTCRetDelta;
+ assert((Delta >= 0) && "Delta must be positive");
+ if (MaxTCRetDelta>0)
+ FrameSize += (StackAdj +Delta);
+ else
+ FrameSize += StackAdj;
+ }
+
+ if (FrameSize) {
+ // The loaded (or persistent) stack pointer value is offset by the 'stwu'
+ // on entry to the function. Add this offset back now.
+ if (!isPPC64) {
+ // If this function contained a fastcc call and GuaranteedTailCallOpt is
+ // enabled (=> hasFastCall()==true) the fastcc call might contain a tail
+ // call which invalidates the stack pointer value in SP(0). So we use the
+ // value of R31 in this case.
+ if (FI->hasFastCall() && isInt<16>(FrameSize)) {
+ assert(hasFP(MF) && "Expecting a valid the frame pointer.");
+ BuildMI(MBB, MBBI, dl, TII.get(PPC::ADDI), PPC::R1)
+ .addReg(PPC::R31).addImm(FrameSize);
+ } else if(FI->hasFastCall()) {
+ BuildMI(MBB, MBBI, dl, TII.get(PPC::LIS), PPC::R0)
+ .addImm(FrameSize >> 16);
+ BuildMI(MBB, MBBI, dl, TII.get(PPC::ORI), PPC::R0)
+ .addReg(PPC::R0, RegState::Kill)
+ .addImm(FrameSize & 0xFFFF);
+ BuildMI(MBB, MBBI, dl, TII.get(PPC::ADD4))
+ .addReg(PPC::R1)
+ .addReg(PPC::R31)
+ .addReg(PPC::R0);
+ } else if (isInt<16>(FrameSize) &&
+ (!ALIGN_STACK || TargetAlign >= MaxAlign) &&
+ !MFI->hasVarSizedObjects()) {
+ BuildMI(MBB, MBBI, dl, TII.get(PPC::ADDI), PPC::R1)
+ .addReg(PPC::R1).addImm(FrameSize);
+ } else {
+ BuildMI(MBB, MBBI, dl, TII.get(PPC::LWZ),PPC::R1)
+ .addImm(0).addReg(PPC::R1);
+ }
+ } else {
+ if (FI->hasFastCall() && isInt<16>(FrameSize)) {
+ assert(hasFP(MF) && "Expecting a valid the frame pointer.");
+ BuildMI(MBB, MBBI, dl, TII.get(PPC::ADDI8), PPC::X1)
+ .addReg(PPC::X31).addImm(FrameSize);
+ } else if(FI->hasFastCall()) {
+ BuildMI(MBB, MBBI, dl, TII.get(PPC::LIS8), PPC::X0)
+ .addImm(FrameSize >> 16);
+ BuildMI(MBB, MBBI, dl, TII.get(PPC::ORI8), PPC::X0)
+ .addReg(PPC::X0, RegState::Kill)
+ .addImm(FrameSize & 0xFFFF);
+ BuildMI(MBB, MBBI, dl, TII.get(PPC::ADD8))
+ .addReg(PPC::X1)
+ .addReg(PPC::X31)
+ .addReg(PPC::X0);
+ } else if (isInt<16>(FrameSize) && TargetAlign >= MaxAlign &&
+ !MFI->hasVarSizedObjects()) {
+ BuildMI(MBB, MBBI, dl, TII.get(PPC::ADDI8), PPC::X1)
+ .addReg(PPC::X1).addImm(FrameSize);
+ } else {
+ BuildMI(MBB, MBBI, dl, TII.get(PPC::LD), PPC::X1)
+ .addImm(0).addReg(PPC::X1);
+ }
+ }
+ }
+
+ if (isPPC64) {
+ if (MustSaveLR)
+ BuildMI(MBB, MBBI, dl, TII.get(PPC::LD), PPC::X0)
+ .addImm(LROffset/4).addReg(PPC::X1);
+
+ if (HasFP)
+ BuildMI(MBB, MBBI, dl, TII.get(PPC::LD), PPC::X31)
+ .addImm(FPOffset/4).addReg(PPC::X1);
+
+ if (MustSaveLR)
+ BuildMI(MBB, MBBI, dl, TII.get(PPC::MTLR8)).addReg(PPC::X0);
+ } else {
+ if (MustSaveLR)
+ BuildMI(MBB, MBBI, dl, TII.get(PPC::LWZ), PPC::R0)
+ .addImm(LROffset).addReg(PPC::R1);
+
+ if (HasFP)
+ BuildMI(MBB, MBBI, dl, TII.get(PPC::LWZ), PPC::R31)
+ .addImm(FPOffset).addReg(PPC::R1);
+
+ if (MustSaveLR)
+ BuildMI(MBB, MBBI, dl, TII.get(PPC::MTLR)).addReg(PPC::R0);
+ }
+
+ // Callee pop calling convention. Pop parameter/linkage area. Used for tail
+ // call optimization
+ if (GuaranteedTailCallOpt && RetOpcode == PPC::BLR &&
+ MF.getFunction()->getCallingConv() == CallingConv::Fast) {
+ PPCFunctionInfo *FI = MF.getInfo<PPCFunctionInfo>();
+ unsigned CallerAllocatedAmt = FI->getMinReservedArea();
+ unsigned StackReg = isPPC64 ? PPC::X1 : PPC::R1;
+ unsigned FPReg = isPPC64 ? PPC::X31 : PPC::R31;
+ unsigned TmpReg = isPPC64 ? PPC::X0 : PPC::R0;
+ unsigned ADDIInstr = isPPC64 ? PPC::ADDI8 : PPC::ADDI;
+ unsigned ADDInstr = isPPC64 ? PPC::ADD8 : PPC::ADD4;
+ unsigned LISInstr = isPPC64 ? PPC::LIS8 : PPC::LIS;
+ unsigned ORIInstr = isPPC64 ? PPC::ORI8 : PPC::ORI;
+
+ if (CallerAllocatedAmt && isInt<16>(CallerAllocatedAmt)) {
+ BuildMI(MBB, MBBI, dl, TII.get(ADDIInstr), StackReg)
+ .addReg(StackReg).addImm(CallerAllocatedAmt);
+ } else {
+ BuildMI(MBB, MBBI, dl, TII.get(LISInstr), TmpReg)
+ .addImm(CallerAllocatedAmt >> 16);
+ BuildMI(MBB, MBBI, dl, TII.get(ORIInstr), TmpReg)
+ .addReg(TmpReg, RegState::Kill)
+ .addImm(CallerAllocatedAmt & 0xFFFF);
+ BuildMI(MBB, MBBI, dl, TII.get(ADDInstr))
+ .addReg(StackReg)
+ .addReg(FPReg)
+ .addReg(TmpReg);
+ }
+ } else if (RetOpcode == PPC::TCRETURNdi) {
+ MBBI = prior(MBB.end());
+ MachineOperand &JumpTarget = MBBI->getOperand(0);
+ BuildMI(MBB, MBBI, dl, TII.get(PPC::TAILB)).
+ addGlobalAddress(JumpTarget.getGlobal(), JumpTarget.getOffset());
+ } else if (RetOpcode == PPC::TCRETURNri) {
+ MBBI = prior(MBB.end());
+ assert(MBBI->getOperand(0).isReg() && "Expecting register operand.");
+ BuildMI(MBB, MBBI, dl, TII.get(PPC::TAILBCTR));
+ } else if (RetOpcode == PPC::TCRETURNai) {
+ MBBI = prior(MBB.end());
+ MachineOperand &JumpTarget = MBBI->getOperand(0);
+ BuildMI(MBB, MBBI, dl, TII.get(PPC::TAILBA)).addImm(JumpTarget.getImm());
+ } else if (RetOpcode == PPC::TCRETURNdi8) {
+ MBBI = prior(MBB.end());
+ MachineOperand &JumpTarget = MBBI->getOperand(0);
+ BuildMI(MBB, MBBI, dl, TII.get(PPC::TAILB8)).
+ addGlobalAddress(JumpTarget.getGlobal(), JumpTarget.getOffset());
+ } else if (RetOpcode == PPC::TCRETURNri8) {
+ MBBI = prior(MBB.end());
+ assert(MBBI->getOperand(0).isReg() && "Expecting register operand.");
+ BuildMI(MBB, MBBI, dl, TII.get(PPC::TAILBCTR8));
+ } else if (RetOpcode == PPC::TCRETURNai8) {
+ MBBI = prior(MBB.end());
+ MachineOperand &JumpTarget = MBBI->getOperand(0);
+ BuildMI(MBB, MBBI, dl, TII.get(PPC::TAILBA8)).addImm(JumpTarget.getImm());
+ }
+}
+
+void PPCFrameLowering::getInitialFrameState(std::vector<MachineMove> &Moves) const {
+ // Initial state of the frame pointer is R1.
+ MachineLocation Dst(MachineLocation::VirtualFP);
+ MachineLocation Src(PPC::R1, 0);
+ Moves.push_back(MachineMove(0, Dst, Src));
+}
+
+static bool spillsCR(const MachineFunction &MF) {
+ const PPCFunctionInfo *FuncInfo = MF.getInfo<PPCFunctionInfo>();
+ return FuncInfo->isCRSpilled();
+}
+
+/// MustSaveLR - Return true if this function requires that we save the LR
+/// register onto the stack in the prolog and restore it in the epilog of the
+/// function.
+static bool MustSaveLR(const MachineFunction &MF, unsigned LR) {
+ const PPCFunctionInfo *MFI = MF.getInfo<PPCFunctionInfo>();
+
+ // We need a save/restore of LR if there is any def of LR (which is
+ // defined by calls, including the PIC setup sequence), or if there is
+ // some use of the LR stack slot (e.g. for builtin_return_address).
+ // (LR comes in 32 and 64 bit versions.)
+ MachineRegisterInfo::def_iterator RI = MF.getRegInfo().def_begin(LR);
+ return RI !=MF.getRegInfo().def_end() || MFI->isLRStoreRequired();
+}
+
+void
+PPCFrameLowering::processFunctionBeforeCalleeSavedScan(MachineFunction &MF,
+ RegScavenger *RS) const {
+ const TargetRegisterInfo *RegInfo = MF.getTarget().getRegisterInfo();
+
+ // Save and clear the LR state.
+ PPCFunctionInfo *FI = MF.getInfo<PPCFunctionInfo>();
+ unsigned LR = RegInfo->getRARegister();
+ FI->setMustSaveLR(MustSaveLR(MF, LR));
+ MF.getRegInfo().setPhysRegUnused(LR);
+
+ // Save R31 if necessary
+ int FPSI = FI->getFramePointerSaveIndex();
+ bool isPPC64 = Subtarget.isPPC64();
+ bool isDarwinABI = Subtarget.isDarwinABI();
+ MachineFrameInfo *MFI = MF.getFrameInfo();
+
+ // If the frame pointer save index hasn't been defined yet.
+ if (!FPSI && needsFP(MF)) {
+ // Find out what the fix offset of the frame pointer save area.
+ int FPOffset = getFramePointerSaveOffset(isPPC64, isDarwinABI);
+ // Allocate the frame index for frame pointer save area.
+ FPSI = MFI->CreateFixedObject(isPPC64? 8 : 4, FPOffset, true);
+ // Save the result.
+ FI->setFramePointerSaveIndex(FPSI);
+ }
+
+ // Reserve stack space to move the linkage area to in case of a tail call.
+ int TCSPDelta = 0;
+ if (GuaranteedTailCallOpt && (TCSPDelta = FI->getTailCallSPDelta()) < 0) {
+ MFI->CreateFixedObject(-1 * TCSPDelta, TCSPDelta, true);
+ }
+
+ // Reserve a slot closest to SP or frame pointer if we have a dynalloc or
+ // a large stack, which will require scavenging a register to materialize a
+ // large offset.
+ // FIXME: this doesn't actually check stack size, so is a bit pessimistic
+ // FIXME: doesn't detect whether or not we need to spill vXX, which requires
+ // r0 for now.
+
+ if (RegInfo->requiresRegisterScavenging(MF)) // FIXME (64-bit): Enable.
+ if (needsFP(MF) || spillsCR(MF)) {
+ const TargetRegisterClass *GPRC = &PPC::GPRCRegClass;
+ const TargetRegisterClass *G8RC = &PPC::G8RCRegClass;
+ const TargetRegisterClass *RC = isPPC64 ? G8RC : GPRC;
+ RS->setScavengingFrameIndex(MFI->CreateStackObject(RC->getSize(),
+ RC->getAlignment(),
+ false));
+ }
+}
+
+void PPCFrameLowering::processFunctionBeforeFrameFinalized(MachineFunction &MF)
+ const {
+ // Early exit if not using the SVR4 ABI.
+ if (!Subtarget.isSVR4ABI())
+ return;
+
+ // Get callee saved register information.
+ MachineFrameInfo *FFI = MF.getFrameInfo();
+ const std::vector<CalleeSavedInfo> &CSI = FFI->getCalleeSavedInfo();
+
+ // Early exit if no callee saved registers are modified!
+ if (CSI.empty() && !needsFP(MF)) {
+ return;
+ }
+
+ unsigned MinGPR = PPC::R31;
+ unsigned MinG8R = PPC::X31;
+ unsigned MinFPR = PPC::F31;
+ unsigned MinVR = PPC::V31;
+
+ bool HasGPSaveArea = false;
+ bool HasG8SaveArea = false;
+ bool HasFPSaveArea = false;
+ bool HasCRSaveArea = false;
+ bool HasVRSAVESaveArea = false;
+ bool HasVRSaveArea = false;
+
+ SmallVector<CalleeSavedInfo, 18> GPRegs;
+ SmallVector<CalleeSavedInfo, 18> G8Regs;
+ SmallVector<CalleeSavedInfo, 18> FPRegs;
+ SmallVector<CalleeSavedInfo, 18> VRegs;
+
+ for (unsigned i = 0, e = CSI.size(); i != e; ++i) {
+ unsigned Reg = CSI[i].getReg();
+ if (PPC::GPRCRegisterClass->contains(Reg)) {
+ HasGPSaveArea = true;
+
+ GPRegs.push_back(CSI[i]);
+
+ if (Reg < MinGPR) {
+ MinGPR = Reg;
+ }
+ } else if (PPC::G8RCRegisterClass->contains(Reg)) {
+ HasG8SaveArea = true;
+
+ G8Regs.push_back(CSI[i]);
+
+ if (Reg < MinG8R) {
+ MinG8R = Reg;
+ }
+ } else if (PPC::F8RCRegisterClass->contains(Reg)) {
+ HasFPSaveArea = true;
+
+ FPRegs.push_back(CSI[i]);
+
+ if (Reg < MinFPR) {
+ MinFPR = Reg;
+ }
+// FIXME SVR4: Disable CR save area for now.
+ } else if (PPC::CRBITRCRegisterClass->contains(Reg)
+ || PPC::CRRCRegisterClass->contains(Reg)) {
+// HasCRSaveArea = true;
+ } else if (PPC::VRSAVERCRegisterClass->contains(Reg)) {
+ HasVRSAVESaveArea = true;
+ } else if (PPC::VRRCRegisterClass->contains(Reg)) {
+ HasVRSaveArea = true;
+
+ VRegs.push_back(CSI[i]);
+
+ if (Reg < MinVR) {
+ MinVR = Reg;
+ }
+ } else {
+ llvm_unreachable("Unknown RegisterClass!");
+ }
+ }
+
+ PPCFunctionInfo *PFI = MF.getInfo<PPCFunctionInfo>();
+
+ int64_t LowerBound = 0;
+
+ // Take into account stack space reserved for tail calls.
+ int TCSPDelta = 0;
+ if (GuaranteedTailCallOpt && (TCSPDelta = PFI->getTailCallSPDelta()) < 0) {
+ LowerBound = TCSPDelta;
+ }
+
+ // The Floating-point register save area is right below the back chain word
+ // of the previous stack frame.
+ if (HasFPSaveArea) {
+ for (unsigned i = 0, e = FPRegs.size(); i != e; ++i) {
+ int FI = FPRegs[i].getFrameIdx();
+
+ FFI->setObjectOffset(FI, LowerBound + FFI->getObjectOffset(FI));
+ }
+
+ LowerBound -= (31 - PPCRegisterInfo::getRegisterNumbering(MinFPR) + 1) * 8;
+ }
+
+ // Check whether the frame pointer register is allocated. If so, make sure it
+ // is spilled to the correct offset.
+ if (needsFP(MF)) {
+ HasGPSaveArea = true;
+
+ int FI = PFI->getFramePointerSaveIndex();
+ assert(FI && "No Frame Pointer Save Slot!");
+
+ FFI->setObjectOffset(FI, LowerBound + FFI->getObjectOffset(FI));
+ }
+
+ // General register save area starts right below the Floating-point
+ // register save area.
+ if (HasGPSaveArea || HasG8SaveArea) {
+ // Move general register save area spill slots down, taking into account
+ // the size of the Floating-point register save area.
+ for (unsigned i = 0, e = GPRegs.size(); i != e; ++i) {
+ int FI = GPRegs[i].getFrameIdx();
+
+ FFI->setObjectOffset(FI, LowerBound + FFI->getObjectOffset(FI));
+ }
+
+ // Move general register save area spill slots down, taking into account
+ // the size of the Floating-point register save area.
+ for (unsigned i = 0, e = G8Regs.size(); i != e; ++i) {
+ int FI = G8Regs[i].getFrameIdx();
+
+ FFI->setObjectOffset(FI, LowerBound + FFI->getObjectOffset(FI));
+ }
+
+ unsigned MinReg =
+ std::min<unsigned>(PPCRegisterInfo::getRegisterNumbering(MinGPR),
+ PPCRegisterInfo::getRegisterNumbering(MinG8R));
+
+ if (Subtarget.isPPC64()) {
+ LowerBound -= (31 - MinReg + 1) * 8;
+ } else {
+ LowerBound -= (31 - MinReg + 1) * 4;
+ }
+ }
+
+ // The CR save area is below the general register save area.
+ if (HasCRSaveArea) {
+ // FIXME SVR4: Is it actually possible to have multiple elements in CSI
+ // which have the CR/CRBIT register class?
+ // Adjust the frame index of the CR spill slot.
+ for (unsigned i = 0, e = CSI.size(); i != e; ++i) {
+ unsigned Reg = CSI[i].getReg();
+
+ if (PPC::CRBITRCRegisterClass->contains(Reg) ||
+ PPC::CRRCRegisterClass->contains(Reg)) {
+ int FI = CSI[i].getFrameIdx();
+
+ FFI->setObjectOffset(FI, LowerBound + FFI->getObjectOffset(FI));
+ }
+ }
+
+ LowerBound -= 4; // The CR save area is always 4 bytes long.
+ }
+
+ if (HasVRSAVESaveArea) {
+ // FIXME SVR4: Is it actually possible to have multiple elements in CSI
+ // which have the VRSAVE register class?
+ // Adjust the frame index of the VRSAVE spill slot.
+ for (unsigned i = 0, e = CSI.size(); i != e; ++i) {
+ unsigned Reg = CSI[i].getReg();
+
+ if (PPC::VRSAVERCRegisterClass->contains(Reg)) {
+ int FI = CSI[i].getFrameIdx();
+
+ FFI->setObjectOffset(FI, LowerBound + FFI->getObjectOffset(FI));
+ }
+ }
+
+ LowerBound -= 4; // The VRSAVE save area is always 4 bytes long.
+ }
+
+ if (HasVRSaveArea) {
+ // Insert alignment padding, we need 16-byte alignment.
+ LowerBound = (LowerBound - 15) & ~(15);
+
+ for (unsigned i = 0, e = VRegs.size(); i != e; ++i) {
+ int FI = VRegs[i].getFrameIdx();
+
+ FFI->setObjectOffset(FI, LowerBound + FFI->getObjectOffset(FI));
+ }
+ }
+}