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

1 files changed, 240 insertions, 3 deletions

diff --git a/lib/Target/XCore/XCoreFrameInfo.cpp b/lib/Target/XCore/XCoreFrameInfo.cpp
index f50dc96c6b..0a7f747cf3 100644
--- a/lib/Target/XCore/XCoreFrameInfo.cpp
+++ b/lib/Target/XCore/XCoreFrameInfo.cpp
@@ -14,14 +14,251 @@
 
 #include "XCore.h"
 #include "XCoreFrameInfo.h"
+#include "XCoreInstrInfo.h"
+#include "XCoreMachineFunctionInfo.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/Target/TargetData.h"
+#include "llvm/Target/TargetOptions.h"
+#include "llvm/Support/ErrorHandling.h"
+
 using namespace llvm;
 
+// helper functions. FIXME: Eliminate.
+static inline bool isImmUs(unsigned val) {
+  return val <= 11;
+}
+
+static inline bool isImmU6(unsigned val) {
+  return val < (1 << 6);
+}
+
+static inline bool isImmU16(unsigned val) {
+  return val < (1 << 16);
+}
+
+static void loadFromStack(MachineBasicBlock &MBB,
+                          MachineBasicBlock::iterator I,
+                          unsigned DstReg, int Offset, DebugLoc dl,
+                          const TargetInstrInfo &TII) {
+  assert(Offset%4 == 0 && "Misaligned stack offset");
+  Offset/=4;
+  bool isU6 = isImmU6(Offset);
+  if (!isU6 && !isImmU16(Offset))
+    report_fatal_error("loadFromStack offset too big " + Twine(Offset));
+  int Opcode = isU6 ? XCore::LDWSP_ru6 : XCore::LDWSP_lru6;
+  BuildMI(MBB, I, dl, TII.get(Opcode), DstReg)
+    .addImm(Offset);
+}
+
+
+static void storeToStack(MachineBasicBlock &MBB,
+                         MachineBasicBlock::iterator I,
+                         unsigned SrcReg, int Offset, DebugLoc dl,
+                         const TargetInstrInfo &TII) {
+  assert(Offset%4 == 0 && "Misaligned stack offset");
+  Offset/=4;
+  bool isU6 = isImmU6(Offset);
+  if (!isU6 && !isImmU16(Offset))
+    report_fatal_error("storeToStack offset too big " + Twine(Offset));
+  int Opcode = isU6 ? XCore::STWSP_ru6 : XCore::STWSP_lru6;
+  BuildMI(MBB, I, dl, TII.get(Opcode))
+    .addReg(SrcReg)
+    .addImm(Offset);
+}
+
+
 //===----------------------------------------------------------------------===//
 // XCoreFrameInfo:
 //===----------------------------------------------------------------------===//
 
-XCoreFrameInfo::XCoreFrameInfo(const TargetMachine &tm):
-  TargetFrameInfo(TargetFrameInfo::StackGrowsDown, 4, 0)
-{
+XCoreFrameInfo::XCoreFrameInfo(const XCoreSubtarget &sti)
+  : TargetFrameInfo(TargetFrameInfo::StackGrowsDown, 4, 0),
+    STI(sti) {
   // Do nothing
 }
+
+void XCoreFrameInfo::emitPrologue(MachineFunction &MF) const {
+  MachineBasicBlock &MBB = MF.front();   // Prolog goes in entry BB
+  MachineBasicBlock::iterator MBBI = MBB.begin();
+  MachineFrameInfo *MFI = MF.getFrameInfo();
+  MachineModuleInfo *MMI = &MF.getMMI();
+  const XCoreRegisterInfo *RegInfo =
+    static_cast<const XCoreRegisterInfo*>(MF.getTarget().getRegisterInfo());
+  const XCoreInstrInfo &TII =
+    *static_cast<const XCoreInstrInfo*>(MF.getTarget().getInstrInfo());
+  XCoreFunctionInfo *XFI = MF.getInfo<XCoreFunctionInfo>();
+  DebugLoc dl = MBBI != MBB.end() ? MBBI->getDebugLoc() : DebugLoc();
+
+  bool FP = RegInfo->hasFP(MF);
+
+  // Work out frame sizes.
+  int FrameSize = MFI->getStackSize();
+  assert(FrameSize%4 == 0 && "Misaligned frame size");
+  FrameSize/=4;
+
+  bool isU6 = isImmU6(FrameSize);
+
+  if (!isU6 && !isImmU16(FrameSize)) {
+    // FIXME could emit multiple instructions.
+    report_fatal_error("emitPrologue Frame size too big: " + Twine(FrameSize));
+  }
+  bool emitFrameMoves = RegInfo->needsFrameMoves(MF);
+
+  // Do we need to allocate space on the stack?
+  if (FrameSize) {
+    bool saveLR = XFI->getUsesLR();
+    bool LRSavedOnEntry = false;
+    int Opcode;
+    if (saveLR && (MFI->getObjectOffset(XFI->getLRSpillSlot()) == 0)) {
+      Opcode = (isU6) ? XCore::ENTSP_u6 : XCore::ENTSP_lu6;
+      MBB.addLiveIn(XCore::LR);
+      saveLR = false;
+      LRSavedOnEntry = true;
+    } else {
+      Opcode = (isU6) ? XCore::EXTSP_u6 : XCore::EXTSP_lu6;
+    }
+    BuildMI(MBB, MBBI, dl, TII.get(Opcode)).addImm(FrameSize);
+
+    if (emitFrameMoves) {
+      std::vector<MachineMove> &Moves = MMI->getFrameMoves();
+
+      // Show update of SP.
+      MCSymbol *FrameLabel = MMI->getContext().CreateTempSymbol();
+      BuildMI(MBB, MBBI, dl, TII.get(XCore::PROLOG_LABEL)).addSym(FrameLabel);
+
+      MachineLocation SPDst(MachineLocation::VirtualFP);
+      MachineLocation SPSrc(MachineLocation::VirtualFP, -FrameSize * 4);
+      Moves.push_back(MachineMove(FrameLabel, SPDst, SPSrc));
+
+      if (LRSavedOnEntry) {
+        MachineLocation CSDst(MachineLocation::VirtualFP, 0);
+        MachineLocation CSSrc(XCore::LR);
+        Moves.push_back(MachineMove(FrameLabel, CSDst, CSSrc));
+      }
+    }
+    if (saveLR) {
+      int LRSpillOffset = MFI->getObjectOffset(XFI->getLRSpillSlot());
+      storeToStack(MBB, MBBI, XCore::LR, LRSpillOffset + FrameSize*4, dl, TII);
+      MBB.addLiveIn(XCore::LR);
+
+      if (emitFrameMoves) {
+        MCSymbol *SaveLRLabel = MMI->getContext().CreateTempSymbol();
+        BuildMI(MBB, MBBI, dl, TII.get(XCore::PROLOG_LABEL)).addSym(SaveLRLabel);
+        MachineLocation CSDst(MachineLocation::VirtualFP, LRSpillOffset);
+        MachineLocation CSSrc(XCore::LR);
+        MMI->getFrameMoves().push_back(MachineMove(SaveLRLabel, CSDst, CSSrc));
+      }
+    }
+  }
+
+  if (FP) {
+    // Save R10 to the stack.
+    int FPSpillOffset = MFI->getObjectOffset(XFI->getFPSpillSlot());
+    storeToStack(MBB, MBBI, XCore::R10, FPSpillOffset + FrameSize*4, dl, TII);
+    // R10 is live-in. It is killed at the spill.
+    MBB.addLiveIn(XCore::R10);
+    if (emitFrameMoves) {
+      MCSymbol *SaveR10Label = MMI->getContext().CreateTempSymbol();
+      BuildMI(MBB, MBBI, dl, TII.get(XCore::PROLOG_LABEL)).addSym(SaveR10Label);
+      MachineLocation CSDst(MachineLocation::VirtualFP, FPSpillOffset);
+      MachineLocation CSSrc(XCore::R10);
+      MMI->getFrameMoves().push_back(MachineMove(SaveR10Label, CSDst, CSSrc));
+    }
+    // Set the FP from the SP.
+    unsigned FramePtr = XCore::R10;
+    BuildMI(MBB, MBBI, dl, TII.get(XCore::LDAWSP_ru6), FramePtr)
+      .addImm(0);
+    if (emitFrameMoves) {
+      // Show FP is now valid.
+      MCSymbol *FrameLabel = MMI->getContext().CreateTempSymbol();
+      BuildMI(MBB, MBBI, dl, TII.get(XCore::PROLOG_LABEL)).addSym(FrameLabel);
+      MachineLocation SPDst(FramePtr);
+      MachineLocation SPSrc(MachineLocation::VirtualFP);
+      MMI->getFrameMoves().push_back(MachineMove(FrameLabel, SPDst, SPSrc));
+    }
+  }
+
+  if (emitFrameMoves) {
+    // Frame moves for callee saved.
+    std::vector<MachineMove> &Moves = MMI->getFrameMoves();
+    std::vector<std::pair<MCSymbol*, CalleeSavedInfo> >&SpillLabels =
+        XFI->getSpillLabels();
+    for (unsigned I = 0, E = SpillLabels.size(); I != E; ++I) {
+      MCSymbol *SpillLabel = SpillLabels[I].first;
+      CalleeSavedInfo &CSI = SpillLabels[I].second;
+      int Offset = MFI->getObjectOffset(CSI.getFrameIdx());
+      unsigned Reg = CSI.getReg();
+      MachineLocation CSDst(MachineLocation::VirtualFP, Offset);
+      MachineLocation CSSrc(Reg);
+      Moves.push_back(MachineMove(SpillLabel, CSDst, CSSrc));
+    }
+  }
+}
+
+void XCoreFrameInfo::emitEpilogue(MachineFunction &MF,
+                                     MachineBasicBlock &MBB) const {
+  MachineFrameInfo *MFI            = MF.getFrameInfo();
+  MachineBasicBlock::iterator MBBI = prior(MBB.end());
+  const XCoreRegisterInfo *RegInfo =
+    static_cast<const XCoreRegisterInfo*>(MF.getTarget().getRegisterInfo());
+  const XCoreInstrInfo &TII =
+    *static_cast<const XCoreInstrInfo*>(MF.getTarget().getInstrInfo());
+  DebugLoc dl = MBBI->getDebugLoc();
+
+  bool FP = RegInfo->hasFP(MF);
+
+  if (FP) {
+    // Restore the stack pointer.
+    unsigned FramePtr = XCore::R10;
+    BuildMI(MBB, MBBI, dl, TII.get(XCore::SETSP_1r))
+      .addReg(FramePtr);
+  }
+
+  // Work out frame sizes.
+  int FrameSize = MFI->getStackSize();
+
+  assert(FrameSize%4 == 0 && "Misaligned frame size");
+
+  FrameSize/=4;
+
+  bool isU6 = isImmU6(FrameSize);
+
+  if (!isU6 && !isImmU16(FrameSize)) {
+    // FIXME could emit multiple instructions.
+    report_fatal_error("emitEpilogue Frame size too big: " + Twine(FrameSize));
+  }
+
+  if (FrameSize) {
+    XCoreFunctionInfo *XFI = MF.getInfo<XCoreFunctionInfo>();
+
+    if (FP) {
+      // Restore R10
+      int FPSpillOffset = MFI->getObjectOffset(XFI->getFPSpillSlot());
+      FPSpillOffset += FrameSize*4;
+      loadFromStack(MBB, MBBI, XCore::R10, FPSpillOffset, dl, TII);
+    }
+    bool restoreLR = XFI->getUsesLR();
+    if (restoreLR && MFI->getObjectOffset(XFI->getLRSpillSlot()) != 0) {
+      int LRSpillOffset = MFI->getObjectOffset(XFI->getLRSpillSlot());
+      LRSpillOffset += FrameSize*4;
+      loadFromStack(MBB, MBBI, XCore::LR, LRSpillOffset, dl, TII);
+      restoreLR = false;
+    }
+    if (restoreLR) {
+      // Fold prologue into return instruction
+      assert(MBBI->getOpcode() == XCore::RETSP_u6
+        || MBBI->getOpcode() == XCore::RETSP_lu6);
+      int Opcode = (isU6) ? XCore::RETSP_u6 : XCore::RETSP_lu6;
+      BuildMI(MBB, MBBI, dl, TII.get(Opcode)).addImm(FrameSize);
+      MBB.erase(MBBI);
+    } else {
+      int Opcode = (isU6) ? XCore::LDAWSP_ru6_RRegs : XCore::LDAWSP_lru6_RRegs;
+      BuildMI(MBB, MBBI, dl, TII.get(Opcode), XCore::SP).addImm(FrameSize);
+    }
+  }
+}