1 files changed, 276 insertions, 0 deletions
diff --git a/lib/Target/CellSPU/SPUFrameLowering.cpp b/lib/Target/CellSPU/SPUFrameLowering.cpp
new file mode 100644
index 0000000000..596d39c441
--- /dev/null
+++ b/lib/Target/CellSPU/SPUFrameLowering.cpp
@@ -0,0 +1,276 @@
+//===-- SPUTargetMachine.cpp - Define TargetMachine for Cell SPU ----------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// Top-level implementation for the Cell SPU target.
+//
+//===----------------------------------------------------------------------===//
+
+#include "SPU.h"
+#include "SPUFrameLowering.h"
+#include "SPURegisterNames.h"
+#include "SPUInstrBuilder.h"
+#include "SPUInstrInfo.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/TargetData.h"
+#include "llvm/Target/TargetOptions.h"
+#include "llvm/Support/CommandLine.h"
+using namespace llvm;
+
+//===----------------------------------------------------------------------===//
+// SPUFrameLowering:
+//===----------------------------------------------------------------------===//
+
+SPUFrameLowering::SPUFrameLowering(const SPUSubtarget &sti)
+  : TargetFrameLowering(TargetFrameLowering::StackGrowsDown, 16, 0),
+    Subtarget(sti) {
+  LR[0].first = SPU::R0;
+  LR[0].second = 16;
+}
+
+
+//--------------------------------------------------------------------------
+// hasFP - Return true if the specified function actually has a dedicated frame
+// pointer register.  This is true if the function needs a frame pointer and has
+// a non-zero stack size.
+bool SPUFrameLowering::hasFP(const MachineFunction &MF) const {
+  const MachineFrameInfo *MFI = MF.getFrameInfo();
+
+  return MFI->getStackSize() &&
+    (DisableFramePointerElim(MF) || MFI->hasVarSizedObjects());
+}
+
+
+/// determineFrameLayout - Determine the size of the frame and maximum call
+/// frame size.
+void SPUFrameLowering::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 TargetAlign = getStackAlignment();
+  unsigned Align = std::max(TargetAlign, MFI->getMaxAlignment());
+  assert(isPowerOf2_32(Align) && "Alignment is not power of 2");
+  unsigned AlignMask = Align - 1;
+
+  // Get the maximum call frame size of all the calls.
+  unsigned maxCallFrameSize = MFI->getMaxCallFrameSize();
+
+  // 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);
+}
+
+void SPUFrameLowering::emitPrologue(MachineFunction &MF) const {
+  MachineBasicBlock &MBB = MF.front();   // Prolog goes in entry BB
+  MachineBasicBlock::iterator MBBI = MBB.begin();
+  MachineFrameInfo *MFI = MF.getFrameInfo();
+  const SPUInstrInfo &TII =
+    *static_cast<const SPUInstrInfo*>(MF.getTarget().getInstrInfo());
+  MachineModuleInfo &MMI = MF.getMMI();
+  DebugLoc dl = MBBI != MBB.end() ? MBBI->getDebugLoc() : DebugLoc();
+
+  // Prepare for debug frame info.
+  bool hasDebugInfo = MMI.hasDebugInfo();
+  MCSymbol *FrameLabel = 0;
+
+  // Move MBBI back to the beginning of the function.
+  MBBI = MBB.begin();
+
+  // Work out frame sizes.
+  determineFrameLayout(MF);
+  int FrameSize = MFI->getStackSize();
+
+  assert((FrameSize & 0xf) == 0
+         && "SPURegisterInfo::emitPrologue: FrameSize not aligned");
+
+  // the "empty" frame size is 16 - just the register scavenger spill slot
+  if (FrameSize > 16 || MFI->adjustsStack()) {
+    FrameSize = -(FrameSize + SPUFrameLowering::minStackSize());
+    if (hasDebugInfo) {
+      // Mark effective beginning of when frame pointer becomes valid.
+      FrameLabel = MMI.getContext().CreateTempSymbol();
+      BuildMI(MBB, MBBI, dl, TII.get(SPU::PROLOG_LABEL)).addSym(FrameLabel);
+    }
+
+    // Adjust stack pointer, spilling $lr -> 16($sp) and $sp -> -FrameSize($sp)
+    // for the ABI
+    BuildMI(MBB, MBBI, dl, TII.get(SPU::STQDr32), SPU::R0).addImm(16)
+      .addReg(SPU::R1);
+    if (isInt<10>(FrameSize)) {
+      // Spill $sp to adjusted $sp
+      BuildMI(MBB, MBBI, dl, TII.get(SPU::STQDr32), SPU::R1).addImm(FrameSize)
+        .addReg(SPU::R1);
+      // Adjust $sp by required amout
+      BuildMI(MBB, MBBI, dl, TII.get(SPU::AIr32), SPU::R1).addReg(SPU::R1)
+        .addImm(FrameSize);
+    } else if (isInt<16>(FrameSize)) {
+      // Frame size can be loaded into ILr32n, so temporarily spill $r2 and use
+      // $r2 to adjust $sp:
+      BuildMI(MBB, MBBI, dl, TII.get(SPU::STQDr128), SPU::R2)
+        .addImm(-16)
+        .addReg(SPU::R1);
+      BuildMI(MBB, MBBI, dl, TII.get(SPU::ILr32), SPU::R2)
+        .addImm(FrameSize);
+      BuildMI(MBB, MBBI, dl, TII.get(SPU::STQXr32), SPU::R1)
+        .addReg(SPU::R2)
+        .addReg(SPU::R1);
+      BuildMI(MBB, MBBI, dl, TII.get(SPU::Ar32), SPU::R1)
+        .addReg(SPU::R1)
+        .addReg(SPU::R2);
+      BuildMI(MBB, MBBI, dl, TII.get(SPU::SFIr32), SPU::R2)
+        .addReg(SPU::R2)
+        .addImm(16);
+      BuildMI(MBB, MBBI, dl, TII.get(SPU::LQXr128), SPU::R2)
+        .addReg(SPU::R2)
+        .addReg(SPU::R1);
+    } else {
+      report_fatal_error("Unhandled frame size: " + Twine(FrameSize));
+    }
+
+    if (hasDebugInfo) {
+      std::vector<MachineMove> &Moves = MMI.getFrameMoves();
+
+      // Show update of SP.
+      MachineLocation SPDst(MachineLocation::VirtualFP);
+      MachineLocation SPSrc(MachineLocation::VirtualFP, -FrameSize);
+      Moves.push_back(MachineMove(FrameLabel, SPDst, SPSrc));
+
+      // 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 == SPU::R0) continue;
+        MachineLocation CSDst(MachineLocation::VirtualFP, Offset);
+        MachineLocation CSSrc(Reg);
+        Moves.push_back(MachineMove(FrameLabel, CSDst, CSSrc));
+      }
+
+      // Mark effective beginning of when frame pointer is ready.
+      MCSymbol *ReadyLabel = MMI.getContext().CreateTempSymbol();
+      BuildMI(MBB, MBBI, dl, TII.get(SPU::PROLOG_LABEL)).addSym(ReadyLabel);
+
+      MachineLocation FPDst(SPU::R1);
+      MachineLocation FPSrc(MachineLocation::VirtualFP);
+      Moves.push_back(MachineMove(ReadyLabel, FPDst, FPSrc));
+    }
+  } else {
+    // This is a leaf function -- insert a branch hint iff there are
+    // sufficient number instructions in the basic block. Note that
+    // this is just a best guess based on the basic block's size.
+    if (MBB.size() >= (unsigned) SPUFrameLowering::branchHintPenalty()) {
+      MachineBasicBlock::iterator MBBI = prior(MBB.end());
+      dl = MBBI->getDebugLoc();
+
+      // Insert terminator label
+      BuildMI(MBB, MBBI, dl, TII.get(SPU::PROLOG_LABEL))
+        .addSym(MMI.getContext().CreateTempSymbol());
+    }
+  }
+}
+
+void SPUFrameLowering::emitEpilogue(MachineFunction &MF,
+                                MachineBasicBlock &MBB) const {
+  MachineBasicBlock::iterator MBBI = prior(MBB.end());
+  const SPUInstrInfo &TII =
+    *static_cast<const SPUInstrInfo*>(MF.getTarget().getInstrInfo());
+  const MachineFrameInfo *MFI = MF.getFrameInfo();
+  int FrameSize = MFI->getStackSize();
+  int LinkSlotOffset = SPUFrameLowering::stackSlotSize();
+  DebugLoc dl = MBBI->getDebugLoc();
+
+  assert(MBBI->getOpcode() == SPU::RET &&
+         "Can only insert epilog into returning blocks");
+  assert((FrameSize & 0xf) == 0 && "FrameSize not aligned");
+
+  // the "empty" frame size is 16 - just the register scavenger spill slot
+  if (FrameSize > 16 || MFI->adjustsStack()) {
+    FrameSize = FrameSize + SPUFrameLowering::minStackSize();
+    if (isInt<10>(FrameSize + LinkSlotOffset)) {
+      // Reload $lr, adjust $sp by required amount
+      // Note: We do this to slightly improve dual issue -- not by much, but it
+      // is an opportunity for dual issue.
+      BuildMI(MBB, MBBI, dl, TII.get(SPU::LQDr128), SPU::R0)
+        .addImm(FrameSize + LinkSlotOffset)
+        .addReg(SPU::R1);
+      BuildMI(MBB, MBBI, dl, TII.get(SPU::AIr32), SPU::R1)
+        .addReg(SPU::R1)
+        .addImm(FrameSize);
+    } else if (FrameSize <= (1 << 16) - 1 && FrameSize >= -(1 << 16)) {
+      // Frame size can be loaded into ILr32n, so temporarily spill $r2 and use
+      // $r2 to adjust $sp:
+      BuildMI(MBB, MBBI, dl, TII.get(SPU::STQDr128), SPU::R2)
+        .addImm(16)
+        .addReg(SPU::R1);
+      BuildMI(MBB, MBBI, dl, TII.get(SPU::ILr32), SPU::R2)
+        .addImm(FrameSize);
+      BuildMI(MBB, MBBI, dl, TII.get(SPU::Ar32), SPU::R1)
+        .addReg(SPU::R1)
+        .addReg(SPU::R2);
+      BuildMI(MBB, MBBI, dl, TII.get(SPU::LQDr128), SPU::R0)
+        .addImm(16)
+        .addReg(SPU::R1);
+      BuildMI(MBB, MBBI, dl, TII.get(SPU::SFIr32), SPU::R2).
+        addReg(SPU::R2)
+        .addImm(16);
+      BuildMI(MBB, MBBI, dl, TII.get(SPU::LQXr128), SPU::R2)
+        .addReg(SPU::R2)
+        .addReg(SPU::R1);
+    } else {
+      report_fatal_error("Unhandled frame size: " + Twine(FrameSize));
+    }
+  }
+}
+
+void SPUFrameLowering::getInitialFrameState(std::vector<MachineMove> &Moves)
+                                                                         const {
+  // Initial state of the frame pointer is R1.
+  MachineLocation Dst(MachineLocation::VirtualFP);
+  MachineLocation Src(SPU::R1, 0);
+  Moves.push_back(MachineMove(0, Dst, Src));
+}
+
+void SPUFrameLowering::processFunctionBeforeCalleeSavedScan(MachineFunction &MF,
+                                                        RegScavenger *RS) const{
+  // Mark LR and SP unused, since the prolog spills them to stack and
+  // we don't want anyone else to spill them for us.
+  //
+  // Also, unless R2 is really used someday, don't spill it automatically.
+  MF.getRegInfo().setPhysRegUnused(SPU::R0);
+  MF.getRegInfo().setPhysRegUnused(SPU::R1);
+  MF.getRegInfo().setPhysRegUnused(SPU::R2);
+
+  MachineFrameInfo *MFI = MF.getFrameInfo();
+  const TargetRegisterClass *RC = &SPU::R32CRegClass;
+  RS->setScavengingFrameIndex(MFI->CreateStackObject(RC->getSize(),
+                                                     RC->getAlignment(),
+                                                     false));
+}