[llvm-commits] [llvm] r91058 - /llvm/trunk/include/llvm/CodeGen/BreakCriticalMachineEdge.h

[Douglas Gregor]

Author: dgregor
Date: Thu Dec 10 13:52:22 2009
New Revision: 91058

URL: http://llvm.org/viewvc/llvm-project?rev=91058&view=rev
Log:
Remove a broken, unused header

Removed:
    llvm/trunk/include/llvm/CodeGen/BreakCriticalMachineEdge.h

Removed: llvm/trunk/include/llvm/CodeGen/BreakCriticalMachineEdge.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/CodeGen/BreakCriticalMachineEdge.h?rev=91057&view=auto

==============================================================================
--- llvm/trunk/include/llvm/CodeGen/BreakCriticalMachineEdge.h (original)
+++ llvm/trunk/include/llvm/CodeGen/BreakCriticalMachineEdge.h (removed)
@@ -1,108 +0,0 @@
-//===--------- BreakCriticalMachineEdge.h - Break critical edges ---------===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is distributed under the University of Illinois Open Source
-// License. See LICENSE.TXT for details.
-//
-//===---------------------------------------------------------------------===//
-//
-// Helper function to break a critical machine edge.
-//
-//===---------------------------------------------------------------------===//
-
-#ifndef LLVM_CODEGEN_BREAKCRITICALMACHINEEDGE_H
-#define LLVM_CODEGEN_BREAKCRITICALMACHINEEDGE_H
-
-#include "llvm/CodeGen/MachineJumpTableInfo.h"
-#include "llvm/Target/TargetInstrInfo.h"
-#include "llvm/Target/TargetMachine.h"
-
-namespace llvm {
-
-MachineBasicBlock* SplitCriticalMachineEdge(MachineBasicBlock* src,
-                                            MachineBasicBlock* dst) {
-  MachineFunction &MF = *src->getParent();
-  const BasicBlock* srcBB = src->getBasicBlock();
-
-  MachineBasicBlock* crit_mbb = MF.CreateMachineBasicBlock(srcBB);
-
-  // modify the llvm control flow graph
-  src->removeSuccessor(dst);
-  src->addSuccessor(crit_mbb);
-  crit_mbb->addSuccessor(dst);
-
-  // insert the new block into the machine function.
-  MF.push_back(crit_mbb);
-
-  // insert a unconditional branch linking the new block to dst
-  const TargetMachine& TM = MF.getTarget();
-  const TargetInstrInfo* TII = TM.getInstrInfo();
-  std::vector<MachineOperand> emptyConditions;
-  TII->InsertBranch(*crit_mbb, dst, (MachineBasicBlock*)0, 
-                    emptyConditions);
-
-  // modify every branch in src that points to dst to point to the new
-  // machine basic block instead:
-  MachineBasicBlock::iterator mii = src->end();
-  bool found_branch = false;
-  while (mii != src->begin()) {
-    mii--;
-    // if there are no more branches, finish the loop
-    if (!mii->getDesc().isTerminator()) {
-      break;
-    }
-
-    // Scan the operands of this branch, replacing any uses of dst with
-    // crit_mbb.
-    for (unsigned i = 0, e = mii->getNumOperands(); i != e; ++i) {
-      MachineOperand & mo = mii->getOperand(i);
-      if (mo.isMBB() && mo.getMBB() == dst) {
-        found_branch = true;
-        mo.setMBB(crit_mbb);
-      }
-    }
-  }
-
-  // TODO: This is tentative. It may be necessary to fix this code. Maybe
-  // I am inserting too many gotos, but I am trusting that the asm printer
-  // will optimize the unnecessary gotos.
-  if(!found_branch) {
-    TII->InsertBranch(*src, crit_mbb, (MachineBasicBlock*)0, 
-                      emptyConditions);
-  }
-
-  /// Change all the phi functions in dst, so that the incoming block be
-  /// crit_mbb, instead of src
-  for(mii = dst->begin(); mii != dst->end(); mii++) {
-    /// the first instructions are always phi functions.
-    if(mii->getOpcode() != TargetInstrInfo::PHI)
-      break;
-
-    // Find the operands corresponding to the source block
-    std::vector<unsigned> toRemove;
-    unsigned reg = 0;
-    for (unsigned u = 0; u != mii->getNumOperands(); ++u)
-      if (mii->getOperand(u).isMBB() &&
-          mii->getOperand(u).getMBB() == src) {
-        reg = mii->getOperand(u-1).getReg();
-        toRemove.push_back(u-1);
-      }
-    // Remove all uses of this MBB
-    for (std::vector<unsigned>::reverse_iterator I = toRemove.rbegin(),
-         E = toRemove.rend(); I != E; ++I) {
-      mii->RemoveOperand(*I+1);
-      mii->RemoveOperand(*I);
-    }
-
-    // Add a single use corresponding to the new MBB
-    mii->addOperand(MachineOperand::CreateReg(reg, false));
-    mii->addOperand(MachineOperand::CreateMBB(crit_mbb));
-  }
-
-  return crit_mbb;
-}
-
-}
-
-#endif