First step of huge frame-related refactoring: move emit{Prologue,Epilogue} out of TargetRegisterInfo to TargetFrameInfo, which is definitely much better suitable place
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@119097 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Target/ARM/ARMFrameInfo.cpp b/lib/Target/ARM/ARMFrameInfo.cpp
new file mode 100644
index 0000000..499111a
--- /dev/null
+++ b/lib/Target/ARM/ARMFrameInfo.cpp
@@ -0,0 +1,376 @@
+//=======- ARMFrameInfo.cpp - ARM 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 ARM implementation of TargetFrameInfo class.
+//
+//===----------------------------------------------------------------------===//
+
+#include "ARMFrameInfo.h"
+#include "ARMBaseInstrInfo.h"
+#include "ARMMachineFunctionInfo.h"
+#include "llvm/CodeGen/MachineFrameInfo.h"
+#include "llvm/CodeGen/MachineFunction.h"
+#include "llvm/CodeGen/MachineInstrBuilder.h"
+
+using namespace llvm;
+
+/// Move iterator past the next bunch of callee save load / store ops for
+/// the particular spill area (1: integer area 1, 2: integer area 2,
+/// 3: fp area, 0: don't care).
+static void movePastCSLoadStoreOps(MachineBasicBlock &MBB,
+ MachineBasicBlock::iterator &MBBI,
+ int Opc1, int Opc2, unsigned Area,
+ const ARMSubtarget &STI) {
+ while (MBBI != MBB.end() &&
+ ((MBBI->getOpcode() == Opc1) || (MBBI->getOpcode() == Opc2)) &&
+ MBBI->getOperand(1).isFI()) {
+ if (Area != 0) {
+ bool Done = false;
+ unsigned Category = 0;
+ switch (MBBI->getOperand(0).getReg()) {
+ case ARM::R4: case ARM::R5: case ARM::R6: case ARM::R7:
+ case ARM::LR:
+ Category = 1;
+ break;
+ case ARM::R8: case ARM::R9: case ARM::R10: case ARM::R11:
+ Category = STI.isTargetDarwin() ? 2 : 1;
+ break;
+ case ARM::D8: case ARM::D9: case ARM::D10: case ARM::D11:
+ case ARM::D12: case ARM::D13: case ARM::D14: case ARM::D15:
+ Category = 3;
+ break;
+ default:
+ Done = true;
+ break;
+ }
+ if (Done || Category != Area)
+ break;
+ }
+
+ ++MBBI;
+ }
+}
+
+static bool isCalleeSavedRegister(unsigned Reg, const unsigned *CSRegs) {
+ for (unsigned i = 0; CSRegs[i]; ++i)
+ if (Reg == CSRegs[i])
+ return true;
+ return false;
+}
+
+static bool isCSRestore(MachineInstr *MI,
+ const ARMBaseInstrInfo &TII,
+ const unsigned *CSRegs) {
+ return ((MI->getOpcode() == (int)ARM::VLDRD ||
+ MI->getOpcode() == (int)ARM::LDRi12 ||
+ MI->getOpcode() == (int)ARM::t2LDRi12) &&
+ MI->getOperand(1).isFI() &&
+ isCalleeSavedRegister(MI->getOperand(0).getReg(), CSRegs));
+}
+
+static void
+emitSPUpdate(bool isARM,
+ MachineBasicBlock &MBB, MachineBasicBlock::iterator &MBBI,
+ DebugLoc dl, const ARMBaseInstrInfo &TII,
+ int NumBytes,
+ ARMCC::CondCodes Pred = ARMCC::AL, unsigned PredReg = 0) {
+ if (isARM)
+ emitARMRegPlusImmediate(MBB, MBBI, dl, ARM::SP, ARM::SP, NumBytes,
+ Pred, PredReg, TII);
+ else
+ emitT2RegPlusImmediate(MBB, MBBI, dl, ARM::SP, ARM::SP, NumBytes,
+ Pred, PredReg, TII);
+}
+
+void ARMFrameInfo::emitPrologue(MachineFunction &MF) const {
+ MachineBasicBlock &MBB = MF.front();
+ MachineBasicBlock::iterator MBBI = MBB.begin();
+ MachineFrameInfo *MFI = MF.getFrameInfo();
+ ARMFunctionInfo *AFI = MF.getInfo<ARMFunctionInfo>();
+ const ARMBaseRegisterInfo *RegInfo =
+ static_cast<const ARMBaseRegisterInfo*>(MF.getTarget().getRegisterInfo());
+ const ARMBaseInstrInfo &TII =
+ *static_cast<const ARMBaseInstrInfo*>(MF.getTarget().getInstrInfo());
+ assert(!AFI->isThumb1OnlyFunction() &&
+ "This emitPrologue does not support Thumb1!");
+ bool isARM = !AFI->isThumbFunction();
+ unsigned VARegSaveSize = AFI->getVarArgsRegSaveSize();
+ unsigned NumBytes = MFI->getStackSize();
+ const std::vector<CalleeSavedInfo> &CSI = MFI->getCalleeSavedInfo();
+ DebugLoc dl = MBBI != MBB.end() ? MBBI->getDebugLoc() : DebugLoc();
+ unsigned FramePtr = RegInfo->getFrameRegister(MF);
+
+ // Determine the sizes of each callee-save spill areas and record which frame
+ // belongs to which callee-save spill areas.
+ unsigned GPRCS1Size = 0, GPRCS2Size = 0, DPRCSSize = 0;
+ int FramePtrSpillFI = 0;
+
+ // Allocate the vararg register save area. This is not counted in NumBytes.
+ if (VARegSaveSize)
+ emitSPUpdate(isARM, MBB, MBBI, dl, TII, -VARegSaveSize);
+
+ if (!AFI->hasStackFrame()) {
+ if (NumBytes != 0)
+ emitSPUpdate(isARM, MBB, MBBI, dl, TII, -NumBytes);
+ return;
+ }
+
+ for (unsigned i = 0, e = CSI.size(); i != e; ++i) {
+ unsigned Reg = CSI[i].getReg();
+ int FI = CSI[i].getFrameIdx();
+ switch (Reg) {
+ case ARM::R4:
+ case ARM::R5:
+ case ARM::R6:
+ case ARM::R7:
+ case ARM::LR:
+ if (Reg == FramePtr)
+ FramePtrSpillFI = FI;
+ AFI->addGPRCalleeSavedArea1Frame(FI);
+ GPRCS1Size += 4;
+ break;
+ case ARM::R8:
+ case ARM::R9:
+ case ARM::R10:
+ case ARM::R11:
+ if (Reg == FramePtr)
+ FramePtrSpillFI = FI;
+ if (STI.isTargetDarwin()) {
+ AFI->addGPRCalleeSavedArea2Frame(FI);
+ GPRCS2Size += 4;
+ } else {
+ AFI->addGPRCalleeSavedArea1Frame(FI);
+ GPRCS1Size += 4;
+ }
+ break;
+ default:
+ AFI->addDPRCalleeSavedAreaFrame(FI);
+ DPRCSSize += 8;
+ }
+ }
+
+ // Build the new SUBri to adjust SP for integer callee-save spill area 1.
+ emitSPUpdate(isARM, MBB, MBBI, dl, TII, -GPRCS1Size);
+ movePastCSLoadStoreOps(MBB, MBBI, ARM::STRi12, ARM::t2STRi12, 1, STI);
+
+ // Set FP to point to the stack slot that contains the previous FP.
+ // For Darwin, FP is R7, which has now been stored in spill area 1.
+ // Otherwise, if this is not Darwin, all the callee-saved registers go
+ // into spill area 1, including the FP in R11. In either case, it is
+ // now safe to emit this assignment.
+ bool HasFP = RegInfo->hasFP(MF);
+ if (HasFP) {
+ unsigned ADDriOpc = !AFI->isThumbFunction() ? ARM::ADDri : ARM::t2ADDri;
+ MachineInstrBuilder MIB =
+ BuildMI(MBB, MBBI, dl, TII.get(ADDriOpc), FramePtr)
+ .addFrameIndex(FramePtrSpillFI).addImm(0);
+ AddDefaultCC(AddDefaultPred(MIB));
+ }
+
+ // Build the new SUBri to adjust SP for integer callee-save spill area 2.
+ emitSPUpdate(isARM, MBB, MBBI, dl, TII, -GPRCS2Size);
+
+ // Build the new SUBri to adjust SP for FP callee-save spill area.
+ movePastCSLoadStoreOps(MBB, MBBI, ARM::STRi12, ARM::t2STRi12, 2, STI);
+ emitSPUpdate(isARM, MBB, MBBI, dl, TII, -DPRCSSize);
+
+ // Determine starting offsets of spill areas.
+ unsigned DPRCSOffset = NumBytes - (GPRCS1Size + GPRCS2Size + DPRCSSize);
+ unsigned GPRCS2Offset = DPRCSOffset + DPRCSSize;
+ unsigned GPRCS1Offset = GPRCS2Offset + GPRCS2Size;
+ if (HasFP)
+ AFI->setFramePtrSpillOffset(MFI->getObjectOffset(FramePtrSpillFI) +
+ NumBytes);
+ AFI->setGPRCalleeSavedArea1Offset(GPRCS1Offset);
+ AFI->setGPRCalleeSavedArea2Offset(GPRCS2Offset);
+ AFI->setDPRCalleeSavedAreaOffset(DPRCSOffset);
+
+ movePastCSLoadStoreOps(MBB, MBBI, ARM::VSTRD, 0, 3, STI);
+ NumBytes = DPRCSOffset;
+ if (NumBytes) {
+ // Adjust SP after all the callee-save spills.
+ emitSPUpdate(isARM, MBB, MBBI, dl, TII, -NumBytes);
+ if (HasFP)
+ AFI->setShouldRestoreSPFromFP(true);
+ }
+
+ if (STI.isTargetELF() && RegInfo->hasFP(MF)) {
+ MFI->setOffsetAdjustment(MFI->getOffsetAdjustment() -
+ AFI->getFramePtrSpillOffset());
+ AFI->setShouldRestoreSPFromFP(true);
+ }
+
+ AFI->setGPRCalleeSavedArea1Size(GPRCS1Size);
+ AFI->setGPRCalleeSavedArea2Size(GPRCS2Size);
+ AFI->setDPRCalleeSavedAreaSize(DPRCSSize);
+
+ // If we need dynamic stack realignment, do it here. Be paranoid and make
+ // sure if we also have VLAs, we have a base pointer for frame access.
+ if (RegInfo->needsStackRealignment(MF)) {
+ unsigned MaxAlign = MFI->getMaxAlignment();
+ assert (!AFI->isThumb1OnlyFunction());
+ if (!AFI->isThumbFunction()) {
+ // Emit bic sp, sp, MaxAlign
+ AddDefaultCC(AddDefaultPred(BuildMI(MBB, MBBI, dl,
+ TII.get(ARM::BICri), ARM::SP)
+ .addReg(ARM::SP, RegState::Kill)
+ .addImm(MaxAlign-1)));
+ } else {
+ // We cannot use sp as source/dest register here, thus we're emitting the
+ // following sequence:
+ // mov r4, sp
+ // bic r4, r4, MaxAlign
+ // mov sp, r4
+ // FIXME: It will be better just to find spare register here.
+ BuildMI(MBB, MBBI, dl, TII.get(ARM::tMOVgpr2tgpr), ARM::R4)
+ .addReg(ARM::SP, RegState::Kill);
+ AddDefaultCC(AddDefaultPred(BuildMI(MBB, MBBI, dl,
+ TII.get(ARM::t2BICri), ARM::R4)
+ .addReg(ARM::R4, RegState::Kill)
+ .addImm(MaxAlign-1)));
+ BuildMI(MBB, MBBI, dl, TII.get(ARM::tMOVtgpr2gpr), ARM::SP)
+ .addReg(ARM::R4, RegState::Kill);
+ }
+
+ AFI->setShouldRestoreSPFromFP(true);
+ }
+
+ // If we need a base pointer, set it up here. It's whatever the value
+ // of the stack pointer is at this point. Any variable size objects
+ // will be allocated after this, so we can still use the base pointer
+ // to reference locals.
+ if (RegInfo->hasBasePointer(MF)) {
+ if (isARM)
+ BuildMI(MBB, MBBI, dl,
+ TII.get(ARM::MOVr), RegInfo->getBaseRegister())
+ .addReg(ARM::SP)
+ .addImm((unsigned)ARMCC::AL).addReg(0).addReg(0);
+ else
+ BuildMI(MBB, MBBI, dl,
+ TII.get(ARM::tMOVgpr2gpr), RegInfo->getBaseRegister())
+ .addReg(ARM::SP);
+ }
+
+ // If the frame has variable sized objects then the epilogue must restore
+ // the sp from fp.
+ if (!AFI->shouldRestoreSPFromFP() && MFI->hasVarSizedObjects())
+ AFI->setShouldRestoreSPFromFP(true);
+}
+
+void ARMFrameInfo::emitEpilogue(MachineFunction &MF,
+ MachineBasicBlock &MBB) const {
+ MachineBasicBlock::iterator MBBI = prior(MBB.end());
+ assert(MBBI->getDesc().isReturn() &&
+ "Can only insert epilog into returning blocks");
+ unsigned RetOpcode = MBBI->getOpcode();
+ DebugLoc dl = MBBI->getDebugLoc();
+ MachineFrameInfo *MFI = MF.getFrameInfo();
+ ARMFunctionInfo *AFI = MF.getInfo<ARMFunctionInfo>();
+ const TargetRegisterInfo *RegInfo = MF.getTarget().getRegisterInfo();
+ const ARMBaseInstrInfo &TII =
+ *static_cast<const ARMBaseInstrInfo*>(MF.getTarget().getInstrInfo());
+ assert(!AFI->isThumb1OnlyFunction() &&
+ "This emitEpilogue does not support Thumb1!");
+ bool isARM = !AFI->isThumbFunction();
+
+ unsigned VARegSaveSize = AFI->getVarArgsRegSaveSize();
+ int NumBytes = (int)MFI->getStackSize();
+ unsigned FramePtr = RegInfo->getFrameRegister(MF);
+
+ if (!AFI->hasStackFrame()) {
+ if (NumBytes != 0)
+ emitSPUpdate(isARM, MBB, MBBI, dl, TII, NumBytes);
+ } else {
+ // Unwind MBBI to point to first LDR / VLDRD.
+ const unsigned *CSRegs = RegInfo->getCalleeSavedRegs();
+ if (MBBI != MBB.begin()) {
+ do
+ --MBBI;
+ while (MBBI != MBB.begin() && isCSRestore(MBBI, TII, CSRegs));
+ if (!isCSRestore(MBBI, TII, CSRegs))
+ ++MBBI;
+ }
+
+ // Move SP to start of FP callee save spill area.
+ NumBytes -= (AFI->getGPRCalleeSavedArea1Size() +
+ AFI->getGPRCalleeSavedArea2Size() +
+ AFI->getDPRCalleeSavedAreaSize());
+
+ // Reset SP based on frame pointer only if the stack frame extends beyond
+ // frame pointer stack slot or target is ELF and the function has FP.
+ if (AFI->shouldRestoreSPFromFP()) {
+ NumBytes = AFI->getFramePtrSpillOffset() - NumBytes;
+ if (NumBytes) {
+ if (isARM)
+ emitARMRegPlusImmediate(MBB, MBBI, dl, ARM::SP, FramePtr, -NumBytes,
+ ARMCC::AL, 0, TII);
+ else
+ emitT2RegPlusImmediate(MBB, MBBI, dl, ARM::SP, FramePtr, -NumBytes,
+ ARMCC::AL, 0, TII);
+ } else {
+ // Thumb2 or ARM.
+ if (isARM)
+ BuildMI(MBB, MBBI, dl, TII.get(ARM::MOVr), ARM::SP)
+ .addReg(FramePtr).addImm((unsigned)ARMCC::AL).addReg(0).addReg(0);
+ else
+ BuildMI(MBB, MBBI, dl, TII.get(ARM::tMOVgpr2gpr), ARM::SP)
+ .addReg(FramePtr);
+ }
+ } else if (NumBytes)
+ emitSPUpdate(isARM, MBB, MBBI, dl, TII, NumBytes);
+
+ // Move SP to start of integer callee save spill area 2.
+ movePastCSLoadStoreOps(MBB, MBBI, ARM::VLDRD, 0, 3, STI);
+ emitSPUpdate(isARM, MBB, MBBI, dl, TII, AFI->getDPRCalleeSavedAreaSize());
+
+ // Move SP to start of integer callee save spill area 1.
+ movePastCSLoadStoreOps(MBB, MBBI, ARM::LDRi12, ARM::t2LDRi12, 2, STI);
+ emitSPUpdate(isARM, MBB, MBBI, dl, TII, AFI->getGPRCalleeSavedArea2Size());
+
+ // Move SP to SP upon entry to the function.
+ movePastCSLoadStoreOps(MBB, MBBI, ARM::LDRi12, ARM::t2LDRi12, 1, STI);
+ emitSPUpdate(isARM, MBB, MBBI, dl, TII, AFI->getGPRCalleeSavedArea1Size());
+ }
+
+ if (RetOpcode == ARM::TCRETURNdi || RetOpcode == ARM::TCRETURNdiND ||
+ RetOpcode == ARM::TCRETURNri || RetOpcode == ARM::TCRETURNriND) {
+ // Tail call return: adjust the stack pointer and jump to callee.
+ MBBI = prior(MBB.end());
+ MachineOperand &JumpTarget = MBBI->getOperand(0);
+
+ // Jump to label or value in register.
+ if (RetOpcode == ARM::TCRETURNdi) {
+ BuildMI(MBB, MBBI, dl,
+ TII.get(STI.isThumb() ? ARM::TAILJMPdt : ARM::TAILJMPd)).
+ addGlobalAddress(JumpTarget.getGlobal(), JumpTarget.getOffset(),
+ JumpTarget.getTargetFlags());
+ } else if (RetOpcode == ARM::TCRETURNdiND) {
+ BuildMI(MBB, MBBI, dl,
+ TII.get(STI.isThumb() ? ARM::TAILJMPdNDt : ARM::TAILJMPdND)).
+ addGlobalAddress(JumpTarget.getGlobal(), JumpTarget.getOffset(),
+ JumpTarget.getTargetFlags());
+ } else if (RetOpcode == ARM::TCRETURNri) {
+ BuildMI(MBB, MBBI, dl, TII.get(ARM::TAILJMPr)).
+ addReg(JumpTarget.getReg(), RegState::Kill);
+ } else if (RetOpcode == ARM::TCRETURNriND) {
+ BuildMI(MBB, MBBI, dl, TII.get(ARM::TAILJMPrND)).
+ addReg(JumpTarget.getReg(), RegState::Kill);
+ }
+
+ MachineInstr *NewMI = prior(MBBI);
+ for (unsigned i = 1, e = MBBI->getNumOperands(); i != e; ++i)
+ NewMI->addOperand(MBBI->getOperand(i));
+
+ // Delete the pseudo instruction TCRETURN.
+ MBB.erase(MBBI);
+ }
+
+ if (VARegSaveSize)
+ emitSPUpdate(isARM, MBB, MBBI, dl, TII, VARegSaveSize);
+}