1 files changed, 0 insertions, 184 deletions
diff --git a/lib/Target/X86/X86PadShortFunction.cpp b/lib/Target/X86/X86PadShortFunction.cpp
deleted file mode 100644
index 05f8a62a75e..00000000000
--- a/lib/Target/X86/X86PadShortFunction.cpp
+++ /dev/null
@@ -1,184 +0,0 @@
-//===-------- X86PadShortFunction.cpp - pad short functions -----------===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is distributed under the University of Illinois Open Source
-// License. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-//
-// This file defines the pass which will pad short functions to prevent
-// a stall if a function returns before the return address is ready. This
-// is needed for some Intel Atom processors.
-//
-//===----------------------------------------------------------------------===//
-
-#include <map>
-#include <algorithm>
-
-#define DEBUG_TYPE "x86-pad-short-functions"
-#include "X86.h"
-#include "X86InstrInfo.h"
-#include "llvm/ADT/Statistic.h"
-#include "llvm/CodeGen/MachineFunctionPass.h"
-#include "llvm/CodeGen/MachineInstrBuilder.h"
-#include "llvm/CodeGen/MachineRegisterInfo.h"
-#include "llvm/CodeGen/Passes.h"
-#include "llvm/Support/Debug.h"
-#include "llvm/Support/raw_ostream.h"
-#include "llvm/Target/TargetInstrInfo.h"
-using namespace llvm;
-
-STATISTIC(NumBBsPadded, "Number of basic blocks padded");
-
-namespace {
-  struct PadShortFunc : public MachineFunctionPass {
-    static char ID;
-    PadShortFunc() : MachineFunctionPass(ID)
-                   , Threshold(4)
-    {}
-
-    virtual bool runOnMachineFunction(MachineFunction &MF);
-
-    virtual const char *getPassName() const
-    {
-      return "X86 Atom pad short functions";
-    }
-
-  private:
-    bool addPadding(MachineFunction &MF,
-                    MachineBasicBlock &MBB,
-                    MachineBasicBlock::iterator &MBBI,
-                    unsigned int NOOPsToAdd);
-
-    void findReturn(MachineFunction &MF,
-                    MachineBasicBlock &MBB,
-                    unsigned int Cycles);
-
-    bool cyclesUntilReturn(MachineFunction &MF,
-                        MachineBasicBlock &MBB,
-                        unsigned int &Cycles,
-                        MachineBasicBlock::iterator *Location = 0);
-
-    const unsigned int Threshold;
-    std::map<int, unsigned int> ReturnBBs;
-  };
-
-  char PadShortFunc::ID = 0;
-}
-
-FunctionPass *llvm::createX86PadShortFunctions() {
-  return new PadShortFunc();
-}
-
-/// runOnMachineFunction - Loop over all of the basic blocks, inserting
-/// NOOP instructions before early exits.
-bool PadShortFunc::runOnMachineFunction(MachineFunction &MF) {
-  // Process all basic blocks.
-  ReturnBBs.clear();
-
-  // Search through basic blocks and mark the ones that have early returns
-  findReturn(MF, *MF.begin(), 0);
-
-  int BBNum;
-  MachineBasicBlock::iterator ReturnLoc;
-  MachineBasicBlock *MBB;
-
-  unsigned int Cycles = 0;
-  unsigned int BBCycles;
-
-  // Pad the identified basic blocks with NOOPs
-  for (std::map<int, unsigned int>::iterator I = ReturnBBs.begin();
-       I != ReturnBBs.end(); ++I) {
-    BBNum = I->first;
-    Cycles = I->second;
-
-    if (Cycles < Threshold) {
-      MBB = MF.getBlockNumbered(BBNum);
-      if (!cyclesUntilReturn(MF, *MBB, BBCycles, &ReturnLoc))
-        continue;
-
-      addPadding(MF, *MBB, ReturnLoc, Threshold - Cycles);
-      NumBBsPadded++;
-    }
-  }
-
-  return false;
-}
-
-/// findReturn - Starting at MBB, follow control flow and add all
-/// basic blocks that contain a return to ReturnBBs.
-void PadShortFunc::findReturn(MachineFunction &MF,
-                              MachineBasicBlock &MBB,
-                              unsigned int Cycles)
-{
-  // If this BB has a return, note how many cycles it takes to get there.
-  bool hasReturn = cyclesUntilReturn(MF, MBB, Cycles);
-  if (Cycles >= Threshold)
-    return;
-
-  if (hasReturn) {
-    int BBNum = MBB.getNumber();
-    ReturnBBs[BBNum] = std::max(ReturnBBs[BBNum], Cycles);
-
-    return;
-  }
-
-  // Follow branches in BB and look for returns
-  for (MachineBasicBlock::succ_iterator I = MBB.succ_begin();
-       I != MBB.succ_end(); ++I) {
-    findReturn(MF, **I, Cycles);
-  }
-}
-
-/// cyclesUntilReturn - if the MBB has a return instruction, set Location to
-/// to the instruction and return true. Return false otherwise.
-/// Cycles will be incremented by the number of cycles taken to reach the
-/// return or the end of the BB, whichever occurs first.
-bool PadShortFunc::cyclesUntilReturn(MachineFunction &MF,
-                                  MachineBasicBlock &MBB,
-                                  unsigned int &Cycles,
-                                  MachineBasicBlock::iterator *Location)
-{
-  const TargetInstrInfo &TII = *MF.getTarget().getInstrInfo();
-  const TargetMachine &Target = MF.getTarget();
-
-  for (MachineBasicBlock::iterator MBBI = MBB.begin(); MBBI != MBB.end();
-       ++MBBI) {
-    MachineInstr *MI = MBBI;
-    // Mark basic blocks with a return instruction. Calls to other functions
-    // do not count because the called function will be padded, if necessary
-    if (MI->isReturn() && !MI->isCall()) {
-      if (Location)
-        *Location = MBBI;
-      return true;
-    }
-
-    Cycles += TII.getInstrLatency(Target.getInstrItineraryData(), MI);
-  }
-
-  return false;
-}
-
-/// addPadding - Add the given number of NOOP instructions to the function
-/// right before the return at MBBI
-bool PadShortFunc::addPadding(MachineFunction &MF,
-                              MachineBasicBlock &MBB,
-                              MachineBasicBlock::iterator &MBBI,
-                              unsigned int NOOPsToAdd)
-{
-  const TargetInstrInfo &TII = *MF.getTarget().getInstrInfo();
-
-  DebugLoc DL = MBBI->getDebugLoc();
-
-  while (NOOPsToAdd-- > 0) {
-    // Since Atom has two instruction execution ports,
-    // the code emits two noops, which will be executed in parallell
-    // during one cycle.
-    BuildMI(MBB, MBBI, DL, TII.get(X86::NOOP));
-    BuildMI(MBB, MBBI, DL, TII.get(X86::NOOP));
-  }
-
-  return true;
-}
-