1 files changed, 369 insertions, 0 deletions
diff --git a/contrib/llvm/lib/Target/Sparc/SparcFrameLowering.cpp b/contrib/llvm/lib/Target/Sparc/SparcFrameLowering.cpp
new file mode 100644
index 0000000..39b5e80
--- /dev/null
+++ b/contrib/llvm/lib/Target/Sparc/SparcFrameLowering.cpp
@@ -0,0 +1,369 @@
+//===-- SparcFrameLowering.cpp - Sparc Frame Information ------------------===//
+//
+//                     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 Sparc implementation of TargetFrameLowering class.
+//
+//===----------------------------------------------------------------------===//
+
+#include "SparcFrameLowering.h"
+#include "SparcInstrInfo.h"
+#include "SparcMachineFunctionInfo.h"
+#include "SparcSubtarget.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/IR/DataLayout.h"
+#include "llvm/IR/Function.h"
+#include "llvm/Support/CommandLine.h"
+#include "llvm/Target/TargetOptions.h"
+
+using namespace llvm;
+
+static cl::opt<bool>
+DisableLeafProc("disable-sparc-leaf-proc",
+                cl::init(false),
+                cl::desc("Disable Sparc leaf procedure optimization."),
+                cl::Hidden);
+
+SparcFrameLowering::SparcFrameLowering(const SparcSubtarget &ST)
+    : TargetFrameLowering(TargetFrameLowering::StackGrowsDown,
+                          ST.is64Bit() ? 16 : 8, 0, ST.is64Bit() ? 16 : 8) {}
+
+void SparcFrameLowering::emitSPAdjustment(MachineFunction &MF,
+                                          MachineBasicBlock &MBB,
+                                          MachineBasicBlock::iterator MBBI,
+                                          int NumBytes,
+                                          unsigned ADDrr,
+                                          unsigned ADDri) const {
+
+  DebugLoc dl;
+  const SparcInstrInfo &TII =
+      *static_cast<const SparcInstrInfo *>(MF.getSubtarget().getInstrInfo());
+
+  if (NumBytes >= -4096 && NumBytes < 4096) {
+    BuildMI(MBB, MBBI, dl, TII.get(ADDri), SP::O6)
+      .addReg(SP::O6).addImm(NumBytes);
+    return;
+  }
+
+  // Emit this the hard way.  This clobbers G1 which we always know is
+  // available here.
+  if (NumBytes >= 0) {
+    // Emit nonnegative numbers with sethi + or.
+    // sethi %hi(NumBytes), %g1
+    // or %g1, %lo(NumBytes), %g1
+    // add %sp, %g1, %sp
+    BuildMI(MBB, MBBI, dl, TII.get(SP::SETHIi), SP::G1)
+      .addImm(HI22(NumBytes));
+    BuildMI(MBB, MBBI, dl, TII.get(SP::ORri), SP::G1)
+      .addReg(SP::G1).addImm(LO10(NumBytes));
+    BuildMI(MBB, MBBI, dl, TII.get(ADDrr), SP::O6)
+      .addReg(SP::O6).addReg(SP::G1);
+    return ;
+  }
+
+  // Emit negative numbers with sethi + xor.
+  // sethi %hix(NumBytes), %g1
+  // xor %g1, %lox(NumBytes), %g1
+  // add %sp, %g1, %sp
+  BuildMI(MBB, MBBI, dl, TII.get(SP::SETHIi), SP::G1)
+    .addImm(HIX22(NumBytes));
+  BuildMI(MBB, MBBI, dl, TII.get(SP::XORri), SP::G1)
+    .addReg(SP::G1).addImm(LOX10(NumBytes));
+  BuildMI(MBB, MBBI, dl, TII.get(ADDrr), SP::O6)
+    .addReg(SP::O6).addReg(SP::G1);
+}
+
+void SparcFrameLowering::emitPrologue(MachineFunction &MF,
+                                      MachineBasicBlock &MBB) const {
+  SparcMachineFunctionInfo *FuncInfo = MF.getInfo<SparcMachineFunctionInfo>();
+
+  assert(&MF.front() == &MBB && "Shrink-wrapping not yet supported");
+  MachineFrameInfo *MFI = MF.getFrameInfo();
+  const SparcInstrInfo &TII =
+      *static_cast<const SparcInstrInfo *>(MF.getSubtarget().getInstrInfo());
+  const SparcRegisterInfo &RegInfo =
+      *static_cast<const SparcRegisterInfo *>(MF.getSubtarget().getRegisterInfo());
+  MachineBasicBlock::iterator MBBI = MBB.begin();
+  // Debug location must be unknown since the first debug location is used
+  // to determine the end of the prologue.
+  DebugLoc dl;
+  bool NeedsStackRealignment = RegInfo.needsStackRealignment(MF);
+
+  // FIXME: unfortunately, returning false from canRealignStack
+  // actually just causes needsStackRealignment to return false,
+  // rather than reporting an error, as would be sensible. This is
+  // poor, but fixing that bogosity is going to be a large project.
+  // For now, just see if it's lied, and report an error here.
+  if (!NeedsStackRealignment && MFI->getMaxAlignment() > getStackAlignment())
+    report_fatal_error("Function \"" + Twine(MF.getName()) + "\" required "
+                       "stack re-alignment, but LLVM couldn't handle it "
+                       "(probably because it has a dynamic alloca).");
+
+  // Get the number of bytes to allocate from the FrameInfo
+  int NumBytes = (int) MFI->getStackSize();
+
+  unsigned SAVEri = SP::SAVEri;
+  unsigned SAVErr = SP::SAVErr;
+  if (FuncInfo->isLeafProc()) {
+    if (NumBytes == 0)
+      return;
+    SAVEri = SP::ADDri;
+    SAVErr = SP::ADDrr;
+  }
+
+  // The SPARC ABI is a bit odd in that it requires a reserved 92-byte
+  // (128 in v9) area in the user's stack, starting at %sp. Thus, the
+  // first part of the stack that can actually be used is located at
+  // %sp + 92.
+  //
+  // We therefore need to add that offset to the total stack size
+  // after all the stack objects are placed by
+  // PrologEpilogInserter calculateFrameObjectOffsets. However, since the stack needs to be
+  // aligned *after* the extra size is added, we need to disable
+  // calculateFrameObjectOffsets's built-in stack alignment, by having
+  // targetHandlesStackFrameRounding return true.
+
+
+  // Add the extra call frame stack size, if needed. (This is the same
+  // code as in PrologEpilogInserter, but also gets disabled by
+  // targetHandlesStackFrameRounding)
+  if (MFI->adjustsStack() && hasReservedCallFrame(MF))
+    NumBytes += MFI->getMaxCallFrameSize();
+
+  // Adds the SPARC subtarget-specific spill area to the stack
+  // size. Also ensures target-required alignment.
+  NumBytes = MF.getSubtarget<SparcSubtarget>().getAdjustedFrameSize(NumBytes);
+
+  // Finally, ensure that the size is sufficiently aligned for the
+  // data on the stack.
+  if (MFI->getMaxAlignment() > 0) {
+    NumBytes = RoundUpToAlignment(NumBytes, MFI->getMaxAlignment());
+  }
+
+  // Update stack size with corrected value.
+  MFI->setStackSize(NumBytes);
+
+  emitSPAdjustment(MF, MBB, MBBI, -NumBytes, SAVErr, SAVEri);
+
+  MachineModuleInfo &MMI = MF.getMMI();
+  unsigned regFP = RegInfo.getDwarfRegNum(SP::I6, true);
+
+  // Emit ".cfi_def_cfa_register 30".
+  unsigned CFIIndex =
+      MMI.addFrameInst(MCCFIInstruction::createDefCfaRegister(nullptr, regFP));
+  BuildMI(MBB, MBBI, dl, TII.get(TargetOpcode::CFI_INSTRUCTION))
+      .addCFIIndex(CFIIndex);
+
+  // Emit ".cfi_window_save".
+  CFIIndex = MMI.addFrameInst(MCCFIInstruction::createWindowSave(nullptr));
+  BuildMI(MBB, MBBI, dl, TII.get(TargetOpcode::CFI_INSTRUCTION))
+      .addCFIIndex(CFIIndex);
+
+  unsigned regInRA = RegInfo.getDwarfRegNum(SP::I7, true);
+  unsigned regOutRA = RegInfo.getDwarfRegNum(SP::O7, true);
+  // Emit ".cfi_register 15, 31".
+  CFIIndex = MMI.addFrameInst(
+      MCCFIInstruction::createRegister(nullptr, regOutRA, regInRA));
+  BuildMI(MBB, MBBI, dl, TII.get(TargetOpcode::CFI_INSTRUCTION))
+      .addCFIIndex(CFIIndex);
+
+  if (NeedsStackRealignment) {
+    // andn %o6, MaxAlign-1, %o6
+    int MaxAlign = MFI->getMaxAlignment();
+    BuildMI(MBB, MBBI, dl, TII.get(SP::ANDNri), SP::O6).addReg(SP::O6).addImm(MaxAlign - 1);
+  }
+}
+
+void SparcFrameLowering::
+eliminateCallFramePseudoInstr(MachineFunction &MF, MachineBasicBlock &MBB,
+                              MachineBasicBlock::iterator I) const {
+  if (!hasReservedCallFrame(MF)) {
+    MachineInstr &MI = *I;
+    int Size = MI.getOperand(0).getImm();
+    if (MI.getOpcode() == SP::ADJCALLSTACKDOWN)
+      Size = -Size;
+
+    if (Size)
+      emitSPAdjustment(MF, MBB, I, Size, SP::ADDrr, SP::ADDri);
+  }
+  MBB.erase(I);
+}
+
+
+void SparcFrameLowering::emitEpilogue(MachineFunction &MF,
+                                  MachineBasicBlock &MBB) const {
+  SparcMachineFunctionInfo *FuncInfo = MF.getInfo<SparcMachineFunctionInfo>();
+  MachineBasicBlock::iterator MBBI = MBB.getLastNonDebugInstr();
+  const SparcInstrInfo &TII =
+      *static_cast<const SparcInstrInfo *>(MF.getSubtarget().getInstrInfo());
+  DebugLoc dl = MBBI->getDebugLoc();
+  assert(MBBI->getOpcode() == SP::RETL &&
+         "Can only put epilog before 'retl' instruction!");
+  if (!FuncInfo->isLeafProc()) {
+    BuildMI(MBB, MBBI, dl, TII.get(SP::RESTORErr), SP::G0).addReg(SP::G0)
+      .addReg(SP::G0);
+    return;
+  }
+  MachineFrameInfo *MFI = MF.getFrameInfo();
+
+  int NumBytes = (int) MFI->getStackSize();
+  if (NumBytes == 0)
+    return;
+
+  emitSPAdjustment(MF, MBB, MBBI, NumBytes, SP::ADDrr, SP::ADDri);
+}
+
+bool SparcFrameLowering::hasReservedCallFrame(const MachineFunction &MF) const {
+  // Reserve call frame if there are no variable sized objects on the stack.
+  return !MF.getFrameInfo()->hasVarSizedObjects();
+}
+
+// hasFP - 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 SparcFrameLowering::hasFP(const MachineFunction &MF) const {
+  const TargetRegisterInfo *RegInfo = MF.getSubtarget().getRegisterInfo();
+
+  const MachineFrameInfo *MFI = MF.getFrameInfo();
+  return MF.getTarget().Options.DisableFramePointerElim(MF) ||
+      RegInfo->needsStackRealignment(MF) ||
+      MFI->hasVarSizedObjects() ||
+      MFI->isFrameAddressTaken();
+}
+
+
+int SparcFrameLowering::getFrameIndexReference(const MachineFunction &MF, int FI,
+                                               unsigned &FrameReg) const {
+  const SparcSubtarget &Subtarget = MF.getSubtarget<SparcSubtarget>();
+  const MachineFrameInfo *MFI = MF.getFrameInfo();
+  const SparcRegisterInfo *RegInfo = Subtarget.getRegisterInfo();
+  const SparcMachineFunctionInfo *FuncInfo = MF.getInfo<SparcMachineFunctionInfo>();
+  bool isFixed = MFI->isFixedObjectIndex(FI);
+
+  // Addressable stack objects are accessed using neg. offsets from
+  // %fp, or positive offsets from %sp.
+  bool UseFP;
+
+  // Sparc uses FP-based references in general, even when "hasFP" is
+  // false. That function is rather a misnomer, because %fp is
+  // actually always available, unless isLeafProc.
+  if (FuncInfo->isLeafProc()) {
+    // If there's a leaf proc, all offsets need to be %sp-based,
+    // because we haven't caused %fp to actually point to our frame.
+    UseFP = false;
+  } else if (isFixed) {
+    // Otherwise, argument access should always use %fp.
+    UseFP = true;
+  } else if (RegInfo->needsStackRealignment(MF)) {
+    // If there is dynamic stack realignment, all local object
+    // references need to be via %sp, to take account of the
+    // re-alignment.
+    UseFP = false;
+  } else {
+    // Finally, default to using %fp.
+    UseFP = true;
+  }
+
+  int64_t FrameOffset = MF.getFrameInfo()->getObjectOffset(FI) +
+      Subtarget.getStackPointerBias();
+
+  if (UseFP) {
+    FrameReg = RegInfo->getFrameRegister(MF);
+    return FrameOffset;
+  } else {
+    FrameReg = SP::O6; // %sp
+    return FrameOffset + MF.getFrameInfo()->getStackSize();
+  }
+}
+
+static bool LLVM_ATTRIBUTE_UNUSED verifyLeafProcRegUse(MachineRegisterInfo *MRI)
+{
+
+  for (unsigned reg = SP::I0; reg <= SP::I7; ++reg)
+    if (!MRI->reg_nodbg_empty(reg))
+      return false;
+
+  for (unsigned reg = SP::L0; reg <= SP::L7; ++reg)
+    if (!MRI->reg_nodbg_empty(reg))
+      return false;
+
+  return true;
+}
+
+bool SparcFrameLowering::isLeafProc(MachineFunction &MF) const
+{
+
+  MachineRegisterInfo &MRI = MF.getRegInfo();
+  MachineFrameInfo    *MFI = MF.getFrameInfo();
+
+  return !(MFI->hasCalls()                 // has calls
+           || !MRI.reg_nodbg_empty(SP::L0) // Too many registers needed
+           || !MRI.reg_nodbg_empty(SP::O6) // %SP is used
+           || hasFP(MF));                  // need %FP
+}
+
+void SparcFrameLowering::remapRegsForLeafProc(MachineFunction &MF) const {
+  MachineRegisterInfo &MRI = MF.getRegInfo();
+  // Remap %i[0-7] to %o[0-7].
+  for (unsigned reg = SP::I0; reg <= SP::I7; ++reg) {
+    if (MRI.reg_nodbg_empty(reg))
+      continue;
+
+    unsigned mapped_reg = reg - SP::I0 + SP::O0;
+    assert(MRI.reg_nodbg_empty(mapped_reg));
+
+    // Replace I register with O register.
+    MRI.replaceRegWith(reg, mapped_reg);
+
+    // Also replace register pair super-registers.
+    if ((reg - SP::I0) % 2 == 0) {
+      unsigned preg = (reg - SP::I0) / 2 + SP::I0_I1;
+      unsigned mapped_preg = preg - SP::I0_I1 + SP::O0_O1;
+      MRI.replaceRegWith(preg, mapped_preg);
+    }
+  }
+
+  // Rewrite MBB's Live-ins.
+  for (MachineFunction::iterator MBB = MF.begin(), E = MF.end();
+       MBB != E; ++MBB) {
+    for (unsigned reg = SP::I0_I1; reg <= SP::I6_I7; ++reg) {
+      if (!MBB->isLiveIn(reg))
+        continue;
+      MBB->removeLiveIn(reg);
+      MBB->addLiveIn(reg - SP::I0_I1 + SP::O0_O1);
+    }
+    for (unsigned reg = SP::I0; reg <= SP::I7; ++reg) {
+      if (!MBB->isLiveIn(reg))
+        continue;
+      MBB->removeLiveIn(reg);
+      MBB->addLiveIn(reg - SP::I0 + SP::O0);
+    }
+  }
+
+  assert(verifyLeafProcRegUse(&MRI));
+#ifdef XDEBUG
+  MF.verify(0, "After LeafProc Remapping");
+#endif
+}
+
+void SparcFrameLowering::determineCalleeSaves(MachineFunction &MF,
+                                              BitVector &SavedRegs,
+                                              RegScavenger *RS) const {
+  TargetFrameLowering::determineCalleeSaves(MF, SavedRegs, RS);
+  if (!DisableLeafProc && isLeafProc(MF)) {
+    SparcMachineFunctionInfo *MFI = MF.getInfo<SparcMachineFunctionInfo>();
+    MFI->setLeafProc(true);
+
+    remapRegsForLeafProc(MF);
+  }
+
+}