Mark these as failing on sparc instead of sparcv9.

The configure script no longer tells us that we're configuring for SparcV9
specifically.
2004-06-17-UnorderedCompares may work on SparcV8, but it's experiental
anyway.
2005-02-20-AggregateSAVEEXPR should fail on any Solaris machine, as Solaris
doesn't provide complex number support.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/branches/release_16@24155 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 358 insertions, 0 deletions

diff --git a/lib/CodeGen/PrologEpilogInserter.cpp b/lib/CodeGen/PrologEpilogInserter.cpp
new file mode 100644
index 0000000000..e38c740e8d
--- /dev/null
+++ b/lib/CodeGen/PrologEpilogInserter.cpp
@@ -0,0 +1,358 @@
+//===-- PrologEpilogInserter.cpp - Insert Prolog/Epilog code in function --===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file was developed by the LLVM research group and is distributed under
+// the University of Illinois Open Source License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This pass is responsible for finalizing the functions frame layout, saving
+// callee saved registers, and for emitting prolog & epilog code for the
+// function.
+//
+// This pass must be run after register allocation.  After this pass is
+// executed, it is illegal to construct MO_FrameIndex operands.
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/CodeGen/Passes.h"
+#include "llvm/CodeGen/MachineFunctionPass.h"
+#include "llvm/CodeGen/MachineInstr.h"
+#include "llvm/CodeGen/MachineFrameInfo.h"
+#include "llvm/Target/TargetMachine.h"
+#include "llvm/Target/MRegisterInfo.h"
+#include "llvm/Target/TargetFrameInfo.h"
+#include "llvm/Target/TargetInstrInfo.h"
+using namespace llvm;
+
+namespace {
+  struct PEI : public MachineFunctionPass {
+    const char *getPassName() const {
+      return "Prolog/Epilog Insertion & Frame Finalization";
+    }
+
+    /// runOnMachineFunction - Insert prolog/epilog code and replace abstract
+    /// frame indexes with appropriate references.
+    ///
+    bool runOnMachineFunction(MachineFunction &Fn) {
+      // Scan the function for modified caller saved registers and insert spill
+      // code for any caller saved registers that are modified.  Also calculate
+      // the MaxCallFrameSize and HasCalls variables for the function's frame
+      // information and eliminates call frame pseudo instructions.
+      calculateCallerSavedRegisters(Fn);
+
+      // Add the code to save and restore the caller saved registers
+      saveCallerSavedRegisters(Fn);
+
+      // Allow the target machine to make final modifications to the function
+      // before the frame layout is finalized.
+      Fn.getTarget().getRegisterInfo()->processFunctionBeforeFrameFinalized(Fn);
+
+      // Calculate actual frame offsets for all of the abstract stack objects...
+      calculateFrameObjectOffsets(Fn);
+
+      // Add prolog and epilog code to the function.  This function is required
+      // to align the stack frame as necessary for any stack variables or
+      // called functions.  Because of this, calculateCallerSavedRegisters
+      // must be called before this function in order to set the HasCalls
+      // and MaxCallFrameSize variables.
+      insertPrologEpilogCode(Fn);
+
+      // Replace all MO_FrameIndex operands with physical register references
+      // and actual offsets.
+      //
+      replaceFrameIndices(Fn);
+
+      RegsToSave.clear();
+      StackSlots.clear();
+      return true;
+    }
+
+  private:
+    std::vector<std::pair<unsigned, const TargetRegisterClass*> > RegsToSave;
+    std::vector<int> StackSlots;
+
+    void calculateCallerSavedRegisters(MachineFunction &Fn);
+    void saveCallerSavedRegisters(MachineFunction &Fn);
+    void calculateFrameObjectOffsets(MachineFunction &Fn);
+    void replaceFrameIndices(MachineFunction &Fn);
+    void insertPrologEpilogCode(MachineFunction &Fn);
+  };
+}
+
+
+/// createPrologEpilogCodeInserter - This function returns a pass that inserts
+/// prolog and epilog code, and eliminates abstract frame references.
+///
+FunctionPass *llvm::createPrologEpilogCodeInserter() { return new PEI(); }
+
+
+/// calculateCallerSavedRegisters - Scan the function for modified caller saved
+/// registers.  Also calculate the MaxCallFrameSize and HasCalls variables for
+/// the function's frame information and eliminates call frame pseudo
+/// instructions.
+///
+void PEI::calculateCallerSavedRegisters(MachineFunction &Fn) {
+  const MRegisterInfo *RegInfo = Fn.getTarget().getRegisterInfo();
+  const TargetFrameInfo *TFI = Fn.getTarget().getFrameInfo();
+  const TargetInstrInfo &TII = *Fn.getTarget().getInstrInfo();
+
+  // Get the callee saved register list...
+  const unsigned *CSRegs = RegInfo->getCalleeSaveRegs();
+
+  // Get the function call frame set-up and tear-down instruction opcode
+  int FrameSetupOpcode   = RegInfo->getCallFrameSetupOpcode();
+  int FrameDestroyOpcode = RegInfo->getCallFrameDestroyOpcode();
+
+  // Early exit for targets which have no callee saved registers and no call
+  // frame setup/destroy pseudo instructions.
+  if ((CSRegs == 0 || CSRegs[0] == 0) &&
+      FrameSetupOpcode == -1 && FrameDestroyOpcode == -1)
+    return;
+
+  unsigned MaxCallFrameSize = 0;
+  bool HasCalls = false;
+
+  for (MachineFunction::iterator BB = Fn.begin(), E = Fn.end(); BB != E; ++BB)
+    for (MachineBasicBlock::iterator I = BB->begin(); I != BB->end(); )
+      if (I->getOpcode() == FrameSetupOpcode ||
+          I->getOpcode() == FrameDestroyOpcode) {
+        assert(I->getNumOperands() >= 1 && "Call Frame Setup/Destroy Pseudo"
+               " instructions should have a single immediate argument!");
+        unsigned Size = I->getOperand(0).getImmedValue();
+        if (Size > MaxCallFrameSize) MaxCallFrameSize = Size;
+        HasCalls = true;
+        RegInfo->eliminateCallFramePseudoInstr(Fn, *BB, I++);
+      } else {
+        ++I;
+      }
+
+  MachineFrameInfo *FFI = Fn.getFrameInfo();
+  FFI->setHasCalls(HasCalls);
+  FFI->setMaxCallFrameSize(MaxCallFrameSize);
+
+  // Now figure out which *callee saved* registers are modified by the current
+  // function, thus needing to be saved and restored in the prolog/epilog.
+  //
+  const bool *PhysRegsUsed = Fn.getUsedPhysregs();
+  const TargetRegisterClass* const *CSRegClasses =
+    RegInfo->getCalleeSaveRegClasses();
+  for (unsigned i = 0; CSRegs[i]; ++i) {
+    unsigned Reg = CSRegs[i];
+    if (PhysRegsUsed[Reg]) {
+        // If the reg is modified, save it!
+      RegsToSave.push_back(std::make_pair(Reg, CSRegClasses[i]));
+    } else {
+      for (const unsigned *AliasSet = RegInfo->getAliasSet(Reg);
+           *AliasSet; ++AliasSet) {  // Check alias registers too.
+        if (PhysRegsUsed[*AliasSet]) {
+          RegsToSave.push_back(std::make_pair(Reg, CSRegClasses[i]));
+          break;
+        }
+      }
+    }
+  }
+
+  if (RegsToSave.empty())
+    return;   // Early exit if no caller saved registers are modified!
+
+  unsigned NumFixedSpillSlots;
+  const std::pair<unsigned,int> *FixedSpillSlots =
+    TFI->getCalleeSaveSpillSlots(NumFixedSpillSlots);
+
+  // Now that we know which registers need to be saved and restored, allocate
+  // stack slots for them.
+  for (unsigned i = 0, e = RegsToSave.size(); i != e; ++i) {
+    unsigned Reg = RegsToSave[i].first;
+    const TargetRegisterClass *RC = RegsToSave[i].second;
+
+    // Check to see if this physreg must be spilled to a particular stack slot
+    // on this target.
+    const std::pair<unsigned,int> *FixedSlot = FixedSpillSlots;
+    while (FixedSlot != FixedSpillSlots+NumFixedSpillSlots &&
+           FixedSlot->first != Reg)
+      ++FixedSlot;
+
+    int FrameIdx;
+    if (FixedSlot == FixedSpillSlots+NumFixedSpillSlots) {
+      // Nope, just spill it anywhere convenient.
+      FrameIdx = FFI->CreateStackObject(RC->getSize(), RC->getAlignment());
+    } else {
+      // Spill it to the stack where we must.
+      FrameIdx = FFI->CreateFixedObject(RC->getSize(), FixedSlot->second);
+    }
+    StackSlots.push_back(FrameIdx);
+  }
+}
+
+/// saveCallerSavedRegisters -  Insert spill code for any caller saved registers
+/// that are modified in the function.
+///
+void PEI::saveCallerSavedRegisters(MachineFunction &Fn) {
+  // Early exit if no caller saved registers are modified!
+  if (RegsToSave.empty())
+    return;
+
+  const MRegisterInfo *RegInfo = Fn.getTarget().getRegisterInfo();
+
+  // Now that we have a stack slot for each register to be saved, insert spill
+  // code into the entry block.
+  MachineBasicBlock *MBB = Fn.begin();
+  MachineBasicBlock::iterator I = MBB->begin();
+  for (unsigned i = 0, e = RegsToSave.size(); i != e; ++i) {
+    // Insert the spill to the stack frame.
+    RegInfo->storeRegToStackSlot(*MBB, I, RegsToSave[i].first, StackSlots[i],
+                                 RegsToSave[i].second);
+  }
+
+  // Add code to restore the callee-save registers in each exiting block.
+  const TargetInstrInfo &TII = *Fn.getTarget().getInstrInfo();
+  for (MachineFunction::iterator FI = Fn.begin(), E = Fn.end(); FI != E; ++FI)
+    // If last instruction is a return instruction, add an epilogue.
+    if (!FI->empty() && TII.isReturn(FI->back().getOpcode())) {
+      MBB = FI;
+      I = MBB->end(); --I;
+
+      // Skip over all terminator instructions, which are part of the return
+      // sequence.
+      MachineBasicBlock::iterator I2 = I;
+      while (I2 != MBB->begin() && TII.isTerminatorInstr((--I2)->getOpcode()))
+        I = I2;
+
+      bool AtStart = I == MBB->begin();
+      MachineBasicBlock::iterator BeforeI = I;
+      if (!AtStart)
+        --BeforeI;
+      
+      // Restore all registers immediately before the return and any terminators
+      // that preceed it.
+      for (unsigned i = 0, e = RegsToSave.size(); i != e; ++i) {
+        RegInfo->loadRegFromStackSlot(*MBB, I, RegsToSave[i].first,
+                                      StackSlots[i], RegsToSave[i].second);
+        assert(I != MBB->begin() &&
+               "loadRegFromStackSlot didn't insert any code!");
+        // Insert in reverse order.  loadRegFromStackSlot can insert multiple
+        // instructions.
+        if (AtStart)
+          I = MBB->begin();
+        else {
+          I = BeforeI;
+          ++I;
+        }
+      }
+    }
+}
+
+
+/// calculateFrameObjectOffsets - Calculate actual frame offsets for all of the
+/// abstract stack objects.
+///
+void PEI::calculateFrameObjectOffsets(MachineFunction &Fn) {
+  const TargetFrameInfo &TFI = *Fn.getTarget().getFrameInfo();
+
+  bool StackGrowsDown =
+    TFI.getStackGrowthDirection() == TargetFrameInfo::StackGrowsDown;
+
+  // Loop over all of the stack objects, assigning sequential addresses...
+  MachineFrameInfo *FFI = Fn.getFrameInfo();
+
+  unsigned StackAlignment = TFI.getStackAlignment();
+
+  // Start at the beginning of the local area.
+  // The Offset is the distance from the stack top in the direction
+  // of stack growth -- so it's always positive.
+  int Offset = TFI.getOffsetOfLocalArea();
+  if (StackGrowsDown)
+    Offset = -Offset;
+  assert(Offset >= 0
+         && "Local area offset should be in direction of stack growth");
+
+  // If there are fixed sized objects that are preallocated in the local area,
+  // non-fixed objects can't be allocated right at the start of local area.
+  // We currently don't support filling in holes in between fixed sized objects,
+  // so we adjust 'Offset' to point to the end of last fixed sized
+  // preallocated object.
+  for (int i = FFI->getObjectIndexBegin(); i != 0; ++i) {
+    int FixedOff;
+    if (StackGrowsDown) {
+      // The maximum distance from the stack pointer is at lower address of
+      // the object -- which is given by offset. For down growing stack
+      // the offset is negative, so we negate the offset to get the distance.
+      FixedOff = -FFI->getObjectOffset(i);
+    } else {
+      // The maximum distance from the start pointer is at the upper
+      // address of the object.
+      FixedOff = FFI->getObjectOffset(i) + FFI->getObjectSize(i);
+    }
+    if (FixedOff > Offset) Offset = FixedOff;
+  }
+
+  for (unsigned i = 0, e = FFI->getObjectIndexEnd(); i != e; ++i) {
+    // If stack grows down, we need to add size of find the lowest
+    // address of the object.
+    if (StackGrowsDown)
+      Offset += FFI->getObjectSize(i);
+
+    unsigned Align = FFI->getObjectAlignment(i);
+    assert(Align <= StackAlignment && "Cannot align stack object to higher "
+           "alignment boundary than the stack itself!");
+    Offset = (Offset+Align-1)/Align*Align;   // Adjust to Alignment boundary...
+
+    if (StackGrowsDown) {
+      FFI->setObjectOffset(i, -Offset);        // Set the computed offset
+    } else {
+      FFI->setObjectOffset(i, Offset);
+      Offset += FFI->getObjectSize(i);
+    }
+  }
+
+  // Align the final stack pointer offset, but only if there are calls in the
+  // function.  This ensures that any calls to subroutines have their stack
+  // frames suitable aligned.
+  if (FFI->hasCalls())
+    Offset = (Offset+StackAlignment-1)/StackAlignment*StackAlignment;
+
+  // Set the final value of the stack pointer...
+  FFI->setStackSize(Offset+TFI.getOffsetOfLocalArea());
+}
+
+
+/// insertPrologEpilogCode - Scan the function for modified caller saved
+/// registers, insert spill code for these caller saved registers, then add
+/// prolog and epilog code to the function.
+///
+void PEI::insertPrologEpilogCode(MachineFunction &Fn) {
+  // Add prologue to the function...
+  Fn.getTarget().getRegisterInfo()->emitPrologue(Fn);
+
+  // Add epilogue to restore the callee-save registers in each exiting block
+  const TargetInstrInfo &TII = *Fn.getTarget().getInstrInfo();
+  for (MachineFunction::iterator I = Fn.begin(), E = Fn.end(); I != E; ++I) {
+    // If last instruction is a return instruction, add an epilogue
+    if (!I->empty() && TII.isReturn(I->back().getOpcode()))
+      Fn.getTarget().getRegisterInfo()->emitEpilogue(Fn, *I);
+  }
+}
+
+
+/// replaceFrameIndices - Replace all MO_FrameIndex operands with physical
+/// register references and actual offsets.
+///
+void PEI::replaceFrameIndices(MachineFunction &Fn) {
+  if (!Fn.getFrameInfo()->hasStackObjects()) return; // Nothing to do?
+
+  const TargetMachine &TM = Fn.getTarget();
+  assert(TM.getRegisterInfo() && "TM::getRegisterInfo() must be implemented!");
+  const MRegisterInfo &MRI = *TM.getRegisterInfo();
+
+  for (MachineFunction::iterator BB = Fn.begin(), E = Fn.end(); BB != E; ++BB)
+    for (MachineBasicBlock::iterator I = BB->begin(); I != BB->end(); ++I)
+      for (unsigned i = 0, e = I->getNumOperands(); i != e; ++i)
+        if (I->getOperand(i).isFrameIndex()) {
+          // If this instruction has a FrameIndex operand, we need to use that
+          // target machine register info object to eliminate it.
+          MRI.eliminateFrameIndex(I);
+          break;
+        }
+}