MachineBasicBlock.cpp revision 0370fad74b48388412c52d1325512f2c218487fa
1aad5c0505183a5b7913f1a443a1f0650122551ccAlkis Evlogimenos//===-- llvm/CodeGen/MachineBasicBlock.cpp ----------------------*- C++ -*-===// 2aad5c0505183a5b7913f1a443a1f0650122551ccAlkis Evlogimenos// 3aad5c0505183a5b7913f1a443a1f0650122551ccAlkis Evlogimenos// The LLVM Compiler Infrastructure 4aad5c0505183a5b7913f1a443a1f0650122551ccAlkis Evlogimenos// 5aad5c0505183a5b7913f1a443a1f0650122551ccAlkis Evlogimenos// This file was developed by the LLVM research group and is distributed under 6aad5c0505183a5b7913f1a443a1f0650122551ccAlkis Evlogimenos// the University of Illinois Open Source License. See LICENSE.TXT for details. 7aad5c0505183a5b7913f1a443a1f0650122551ccAlkis Evlogimenos// 8aad5c0505183a5b7913f1a443a1f0650122551ccAlkis Evlogimenos//===----------------------------------------------------------------------===// 9aad5c0505183a5b7913f1a443a1f0650122551ccAlkis Evlogimenos// 10aad5c0505183a5b7913f1a443a1f0650122551ccAlkis Evlogimenos// Collect the sequence of machine instructions for a basic block. 11aad5c0505183a5b7913f1a443a1f0650122551ccAlkis Evlogimenos// 12aad5c0505183a5b7913f1a443a1f0650122551ccAlkis Evlogimenos//===----------------------------------------------------------------------===// 13aad5c0505183a5b7913f1a443a1f0650122551ccAlkis Evlogimenos 14aad5c0505183a5b7913f1a443a1f0650122551ccAlkis Evlogimenos#include "llvm/CodeGen/MachineBasicBlock.h" 15aad5c0505183a5b7913f1a443a1f0650122551ccAlkis Evlogimenos#include "llvm/BasicBlock.h" 16aad5c0505183a5b7913f1a443a1f0650122551ccAlkis Evlogimenos#include "llvm/CodeGen/MachineFunction.h" 17aad5c0505183a5b7913f1a443a1f0650122551ccAlkis Evlogimenos#include "llvm/CodeGen/MachineInstr.h" 1813d828567812041c1ca1817f4b66fce840903a1fEvan Cheng#include "llvm/Target/MRegisterInfo.h" 1907000c6f01d8f57170f2d4c77a86d934bdc5c696Owen Anderson#include "llvm/Target/TargetData.h" 20743d0a1f831f1d5a3141a6ca730558f40c35690aAlkis Evlogimenos#include "llvm/Target/TargetInstrInfo.h" 21743d0a1f831f1d5a3141a6ca730558f40c35690aAlkis Evlogimenos#include "llvm/Target/TargetMachine.h" 22551ccae044b0ff658fe629dd67edd5ffe75d10e8Reid Spencer#include "llvm/Support/LeakDetector.h" 2352c09d76564d6fb24444c4d56bc8978e042e72f9Chris Lattner#include <algorithm> 24aad5c0505183a5b7913f1a443a1f0650122551ccAlkis Evlogimenosusing namespace llvm; 25aad5c0505183a5b7913f1a443a1f0650122551ccAlkis Evlogimenos 2617fb34bf8cd10a798c9206eeef3bff151b4d3688Tanya LattnerMachineBasicBlock::~MachineBasicBlock() { 2717fb34bf8cd10a798c9206eeef3bff151b4d3688Tanya Lattner LeakDetector::removeGarbageObject(this); 2817fb34bf8cd10a798c9206eeef3bff151b4d3688Tanya Lattner} 2917fb34bf8cd10a798c9206eeef3bff151b4d3688Tanya Lattner 301ccc4684f3413d1f176a2c7a867545ce03b6414cChris Lattnerstd::ostream& llvm::operator<<(std::ostream &OS, const MachineBasicBlock &MBB) { 311ccc4684f3413d1f176a2c7a867545ce03b6414cChris Lattner MBB.print(OS); 321ccc4684f3413d1f176a2c7a867545ce03b6414cChris Lattner return OS; 331ccc4684f3413d1f176a2c7a867545ce03b6414cChris Lattner} 3417fb34bf8cd10a798c9206eeef3bff151b4d3688Tanya Lattner 35a63828619feaeee7a7468ab00c50c3d678afae55Alkis Evlogimenos// MBBs start out as #-1. When a MBB is added to a MachineFunction, it 360bcb1ad7be8515492ba02f64c0e43113ecdf8e32Brian Gaeke// gets the next available unique MBB number. If it is removed from a 370bcb1ad7be8515492ba02f64c0e43113ecdf8e32Brian Gaeke// MachineFunction, it goes back to being #-1. 38ca48eb9f5175058a55c1818cb1d5d06052f0092dChris Lattnervoid ilist_traits<MachineBasicBlock>::addNodeToList(MachineBasicBlock* N) { 39792699c46ef9bfc47dd459bbfa7e71bcb2cee29aTanya Lattner assert(N->Parent == 0 && "machine instruction already in a basic block"); 4017fb34bf8cd10a798c9206eeef3bff151b4d3688Tanya Lattner N->Parent = Parent; 41ca48eb9f5175058a55c1818cb1d5d06052f0092dChris Lattner N->Number = Parent->addToMBBNumbering(N); 42792699c46ef9bfc47dd459bbfa7e71bcb2cee29aTanya Lattner LeakDetector::removeGarbageObject(N); 430bcb1ad7be8515492ba02f64c0e43113ecdf8e32Brian Gaeke} 440bcb1ad7be8515492ba02f64c0e43113ecdf8e32Brian Gaeke 45ca48eb9f5175058a55c1818cb1d5d06052f0092dChris Lattnervoid ilist_traits<MachineBasicBlock>::removeNodeFromList(MachineBasicBlock* N) { 46792699c46ef9bfc47dd459bbfa7e71bcb2cee29aTanya Lattner assert(N->Parent != 0 && "machine instruction not in a basic block"); 47ca48eb9f5175058a55c1818cb1d5d06052f0092dChris Lattner N->Parent->removeFromMBBNumbering(N->Number); 480bcb1ad7be8515492ba02f64c0e43113ecdf8e32Brian Gaeke N->Number = -1; 49ca48eb9f5175058a55c1818cb1d5d06052f0092dChris Lattner N->Parent = 0; 50792699c46ef9bfc47dd459bbfa7e71bcb2cee29aTanya Lattner LeakDetector::addGarbageObject(N); 510bcb1ad7be8515492ba02f64c0e43113ecdf8e32Brian Gaeke} 520bcb1ad7be8515492ba02f64c0e43113ecdf8e32Brian Gaeke 535e61fa95196b85281eec655787e9c73267532bd1Chris Lattner 54bca81448ac8e19c588c9a4ad16fc70732b76327cChris LattnerMachineInstr* ilist_traits<MachineInstr>::createSentinel() { 55c0f64ffab93d11fb27a3b8a0707b77400918a20eEvan Cheng MachineInstr* dummy = new MachineInstr(); 56a63828619feaeee7a7468ab00c50c3d678afae55Alkis Evlogimenos LeakDetector::removeGarbageObject(dummy); 57a63828619feaeee7a7468ab00c50c3d678afae55Alkis Evlogimenos return dummy; 58aad5c0505183a5b7913f1a443a1f0650122551ccAlkis Evlogimenos} 59aad5c0505183a5b7913f1a443a1f0650122551ccAlkis Evlogimenos 6052c09d76564d6fb24444c4d56bc8978e042e72f9Chris Lattnervoid ilist_traits<MachineInstr>::addNodeToList(MachineInstr* N) { 61a63828619feaeee7a7468ab00c50c3d678afae55Alkis Evlogimenos assert(N->parent == 0 && "machine instruction already in a basic block"); 62a63828619feaeee7a7468ab00c50c3d678afae55Alkis Evlogimenos N->parent = parent; 63a63828619feaeee7a7468ab00c50c3d678afae55Alkis Evlogimenos LeakDetector::removeGarbageObject(N); 64aad5c0505183a5b7913f1a443a1f0650122551ccAlkis Evlogimenos} 65aad5c0505183a5b7913f1a443a1f0650122551ccAlkis Evlogimenos 6652c09d76564d6fb24444c4d56bc8978e042e72f9Chris Lattnervoid ilist_traits<MachineInstr>::removeNodeFromList(MachineInstr* N) { 67a63828619feaeee7a7468ab00c50c3d678afae55Alkis Evlogimenos assert(N->parent != 0 && "machine instruction not in a basic block"); 68a63828619feaeee7a7468ab00c50c3d678afae55Alkis Evlogimenos N->parent = 0; 69a63828619feaeee7a7468ab00c50c3d678afae55Alkis Evlogimenos LeakDetector::addGarbageObject(N); 70aad5c0505183a5b7913f1a443a1f0650122551ccAlkis Evlogimenos} 71aad5c0505183a5b7913f1a443a1f0650122551ccAlkis Evlogimenos 72aad5c0505183a5b7913f1a443a1f0650122551ccAlkis Evlogimenosvoid ilist_traits<MachineInstr>::transferNodesFromList( 735504602836de40f07ac390a836161e45389870c2Chris Lattner iplist<MachineInstr, ilist_traits<MachineInstr> >& fromList, 74a63828619feaeee7a7468ab00c50c3d678afae55Alkis Evlogimenos ilist_iterator<MachineInstr> first, 7552c09d76564d6fb24444c4d56bc8978e042e72f9Chris Lattner ilist_iterator<MachineInstr> last) { 765504602836de40f07ac390a836161e45389870c2Chris Lattner if (parent != fromList.parent) 77a63828619feaeee7a7468ab00c50c3d678afae55Alkis Evlogimenos for (; first != last; ++first) 785504602836de40f07ac390a836161e45389870c2Chris Lattner first->parent = parent; 79aad5c0505183a5b7913f1a443a1f0650122551ccAlkis Evlogimenos} 80aad5c0505183a5b7913f1a443a1f0650122551ccAlkis Evlogimenos 8152c09d76564d6fb24444c4d56bc8978e042e72f9Chris LattnerMachineBasicBlock::iterator MachineBasicBlock::getFirstTerminator() { 829bcdcd17c7219dbc68de2f11ca2de86471c8c390Chris Lattner const TargetInstrInfo& TII = *getParent()->getTarget().getInstrInfo(); 83743d0a1f831f1d5a3141a6ca730558f40c35690aAlkis Evlogimenos iterator I = end(); 84743d0a1f831f1d5a3141a6ca730558f40c35690aAlkis Evlogimenos while (I != begin() && TII.isTerminatorInstr((--I)->getOpcode())); 85743d0a1f831f1d5a3141a6ca730558f40c35690aAlkis Evlogimenos if (I != end() && !TII.isTerminatorInstr(I->getOpcode())) ++I; 86743d0a1f831f1d5a3141a6ca730558f40c35690aAlkis Evlogimenos return I; 87743d0a1f831f1d5a3141a6ca730558f40c35690aAlkis Evlogimenos} 88743d0a1f831f1d5a3141a6ca730558f40c35690aAlkis Evlogimenos 8952c09d76564d6fb24444c4d56bc8978e042e72f9Chris Lattnervoid MachineBasicBlock::dump() const { 90bcd2498f4f1682dbdc41452add5b9bc72cbd6b3fBill Wendling print(*cerr.stream()); 91aad5c0505183a5b7913f1a443a1f0650122551ccAlkis Evlogimenos} 92aad5c0505183a5b7913f1a443a1f0650122551ccAlkis Evlogimenos 9313d828567812041c1ca1817f4b66fce840903a1fEvan Chengstatic inline void OutputReg(std::ostream &os, unsigned RegNo, 9413d828567812041c1ca1817f4b66fce840903a1fEvan Cheng const MRegisterInfo *MRI = 0) { 9513d828567812041c1ca1817f4b66fce840903a1fEvan Cheng if (!RegNo || MRegisterInfo::isPhysicalRegister(RegNo)) { 9613d828567812041c1ca1817f4b66fce840903a1fEvan Cheng if (MRI) 9713d828567812041c1ca1817f4b66fce840903a1fEvan Cheng os << " %" << MRI->get(RegNo).Name; 9813d828567812041c1ca1817f4b66fce840903a1fEvan Cheng else 9913d828567812041c1ca1817f4b66fce840903a1fEvan Cheng os << " %mreg(" << RegNo << ")"; 10013d828567812041c1ca1817f4b66fce840903a1fEvan Cheng } else 10113d828567812041c1ca1817f4b66fce840903a1fEvan Cheng os << " %reg" << RegNo; 10213d828567812041c1ca1817f4b66fce840903a1fEvan Cheng} 10313d828567812041c1ca1817f4b66fce840903a1fEvan Cheng 10452c09d76564d6fb24444c4d56bc8978e042e72f9Chris Lattnervoid MachineBasicBlock::print(std::ostream &OS) const { 10513d828567812041c1ca1817f4b66fce840903a1fEvan Cheng const MachineFunction *MF = getParent(); 10613d828567812041c1ca1817f4b66fce840903a1fEvan Cheng if(!MF) { 10752c09d76564d6fb24444c4d56bc8978e042e72f9Chris Lattner OS << "Can't print out MachineBasicBlock because parent MachineFunction" 10852c09d76564d6fb24444c4d56bc8978e042e72f9Chris Lattner << " is null\n"; 109792699c46ef9bfc47dd459bbfa7e71bcb2cee29aTanya Lattner return; 110792699c46ef9bfc47dd459bbfa7e71bcb2cee29aTanya Lattner } 111a63828619feaeee7a7468ab00c50c3d678afae55Alkis Evlogimenos 112a63828619feaeee7a7468ab00c50c3d678afae55Alkis Evlogimenos const BasicBlock *LBB = getBasicBlock(); 113db3ea6754bc314cb0ba5b4c2ae534b3b33633cf1Chris Lattner OS << "\n"; 114c11ce86943847a95ee20b65b4d1fc4611b59ddc6Chris Lattner if (LBB) OS << LBB->getName() << ": "; 115c11ce86943847a95ee20b65b4d1fc4611b59ddc6Chris Lattner OS << (const void*)this 116c11ce86943847a95ee20b65b4d1fc4611b59ddc6Chris Lattner << ", LLVM BB @" << (const void*) LBB << ", ID#" << getNumber(); 117c11ce86943847a95ee20b65b4d1fc4611b59ddc6Chris Lattner if (isLandingPad()) OS << ", EH LANDING PAD"; 118c11ce86943847a95ee20b65b4d1fc4611b59ddc6Chris Lattner OS << ":\n"; 11913d828567812041c1ca1817f4b66fce840903a1fEvan Cheng 12013d828567812041c1ca1817f4b66fce840903a1fEvan Cheng const MRegisterInfo *MRI = MF->getTarget().getRegisterInfo(); 12113d828567812041c1ca1817f4b66fce840903a1fEvan Cheng if (livein_begin() != livein_end()) { 12213d828567812041c1ca1817f4b66fce840903a1fEvan Cheng OS << "Live Ins:"; 123b371f457b0ea4a652a9f526ba4375c80ae542252Evan Cheng for (const_livein_iterator I = livein_begin(),E = livein_end(); I != E; ++I) 12413d828567812041c1ca1817f4b66fce840903a1fEvan Cheng OutputReg(OS, *I, MRI); 12513d828567812041c1ca1817f4b66fce840903a1fEvan Cheng OS << "\n"; 12613d828567812041c1ca1817f4b66fce840903a1fEvan Cheng } 127681764b20c3418b4af783a84eb2a68145d69a9d7Chris Lattner // Print the preds of this block according to the CFG. 128681764b20c3418b4af783a84eb2a68145d69a9d7Chris Lattner if (!pred_empty()) { 129681764b20c3418b4af783a84eb2a68145d69a9d7Chris Lattner OS << " Predecessors according to CFG:"; 130681764b20c3418b4af783a84eb2a68145d69a9d7Chris Lattner for (const_pred_iterator PI = pred_begin(), E = pred_end(); PI != E; ++PI) 131219705131d5f6911d4b40fcfdcc614a7f3a5e035Evan Cheng OS << " " << *PI << " (#" << (*PI)->getNumber() << ")"; 132681764b20c3418b4af783a84eb2a68145d69a9d7Chris Lattner OS << "\n"; 133681764b20c3418b4af783a84eb2a68145d69a9d7Chris Lattner } 134681764b20c3418b4af783a84eb2a68145d69a9d7Chris Lattner 135a63828619feaeee7a7468ab00c50c3d678afae55Alkis Evlogimenos for (const_iterator I = begin(); I != end(); ++I) { 136a63828619feaeee7a7468ab00c50c3d678afae55Alkis Evlogimenos OS << "\t"; 137a63828619feaeee7a7468ab00c50c3d678afae55Alkis Evlogimenos I->print(OS, &getParent()->getTarget()); 138a63828619feaeee7a7468ab00c50c3d678afae55Alkis Evlogimenos } 139380ae495996c84f348d12224ea9f4514f6471f59Chris Lattner 140380ae495996c84f348d12224ea9f4514f6471f59Chris Lattner // Print the successors of this block according to the CFG. 141380ae495996c84f348d12224ea9f4514f6471f59Chris Lattner if (!succ_empty()) { 142380ae495996c84f348d12224ea9f4514f6471f59Chris Lattner OS << " Successors according to CFG:"; 143380ae495996c84f348d12224ea9f4514f6471f59Chris Lattner for (const_succ_iterator SI = succ_begin(), E = succ_end(); SI != E; ++SI) 144219705131d5f6911d4b40fcfdcc614a7f3a5e035Evan Cheng OS << " " << *SI << " (#" << (*SI)->getNumber() << ")"; 145380ae495996c84f348d12224ea9f4514f6471f59Chris Lattner OS << "\n"; 146380ae495996c84f348d12224ea9f4514f6471f59Chris Lattner } 147aad5c0505183a5b7913f1a443a1f0650122551ccAlkis Evlogimenos} 14852c09d76564d6fb24444c4d56bc8978e042e72f9Chris Lattner 149b371f457b0ea4a652a9f526ba4375c80ae542252Evan Chengvoid MachineBasicBlock::removeLiveIn(unsigned Reg) { 150b371f457b0ea4a652a9f526ba4375c80ae542252Evan Cheng livein_iterator I = std::find(livein_begin(), livein_end(), Reg); 151b371f457b0ea4a652a9f526ba4375c80ae542252Evan Cheng assert(I != livein_end() && "Not a live in!"); 152b371f457b0ea4a652a9f526ba4375c80ae542252Evan Cheng LiveIns.erase(I); 153b371f457b0ea4a652a9f526ba4375c80ae542252Evan Cheng} 154b371f457b0ea4a652a9f526ba4375c80ae542252Evan Cheng 155c585a3f62adb2e491d792115af637ef75bdf489eChris Lattnervoid MachineBasicBlock::moveBefore(MachineBasicBlock *NewAfter) { 156c585a3f62adb2e491d792115af637ef75bdf489eChris Lattner MachineFunction::BasicBlockListType &BBList =getParent()->getBasicBlockList(); 157c585a3f62adb2e491d792115af637ef75bdf489eChris Lattner getParent()->getBasicBlockList().splice(NewAfter, BBList, this); 158c585a3f62adb2e491d792115af637ef75bdf489eChris Lattner} 159c585a3f62adb2e491d792115af637ef75bdf489eChris Lattner 160c585a3f62adb2e491d792115af637ef75bdf489eChris Lattnervoid MachineBasicBlock::moveAfter(MachineBasicBlock *NewBefore) { 161c585a3f62adb2e491d792115af637ef75bdf489eChris Lattner MachineFunction::BasicBlockListType &BBList =getParent()->getBasicBlockList(); 162c585a3f62adb2e491d792115af637ef75bdf489eChris Lattner MachineFunction::iterator BBI = NewBefore; 163c585a3f62adb2e491d792115af637ef75bdf489eChris Lattner getParent()->getBasicBlockList().splice(++BBI, BBList, this); 164c585a3f62adb2e491d792115af637ef75bdf489eChris Lattner} 165c585a3f62adb2e491d792115af637ef75bdf489eChris Lattner 166c585a3f62adb2e491d792115af637ef75bdf489eChris Lattner 16752c09d76564d6fb24444c4d56bc8978e042e72f9Chris Lattnervoid MachineBasicBlock::addSuccessor(MachineBasicBlock *succ) { 16852c09d76564d6fb24444c4d56bc8978e042e72f9Chris Lattner Successors.push_back(succ); 16952c09d76564d6fb24444c4d56bc8978e042e72f9Chris Lattner succ->addPredecessor(this); 17052c09d76564d6fb24444c4d56bc8978e042e72f9Chris Lattner} 17152c09d76564d6fb24444c4d56bc8978e042e72f9Chris Lattner 17252c09d76564d6fb24444c4d56bc8978e042e72f9Chris Lattnervoid MachineBasicBlock::removeSuccessor(MachineBasicBlock *succ) { 17352c09d76564d6fb24444c4d56bc8978e042e72f9Chris Lattner succ->removePredecessor(this); 17452c09d76564d6fb24444c4d56bc8978e042e72f9Chris Lattner succ_iterator I = std::find(Successors.begin(), Successors.end(), succ); 17552c09d76564d6fb24444c4d56bc8978e042e72f9Chris Lattner assert(I != Successors.end() && "Not a current successor!"); 17652c09d76564d6fb24444c4d56bc8978e042e72f9Chris Lattner Successors.erase(I); 17752c09d76564d6fb24444c4d56bc8978e042e72f9Chris Lattner} 17852c09d76564d6fb24444c4d56bc8978e042e72f9Chris Lattner 17952c09d76564d6fb24444c4d56bc8978e042e72f9Chris Lattnervoid MachineBasicBlock::removeSuccessor(succ_iterator I) { 18052c09d76564d6fb24444c4d56bc8978e042e72f9Chris Lattner assert(I != Successors.end() && "Not a current successor!"); 18152c09d76564d6fb24444c4d56bc8978e042e72f9Chris Lattner (*I)->removePredecessor(this); 18252c09d76564d6fb24444c4d56bc8978e042e72f9Chris Lattner Successors.erase(I); 18352c09d76564d6fb24444c4d56bc8978e042e72f9Chris Lattner} 18452c09d76564d6fb24444c4d56bc8978e042e72f9Chris Lattner 18552c09d76564d6fb24444c4d56bc8978e042e72f9Chris Lattnervoid MachineBasicBlock::addPredecessor(MachineBasicBlock *pred) { 18652c09d76564d6fb24444c4d56bc8978e042e72f9Chris Lattner Predecessors.push_back(pred); 18752c09d76564d6fb24444c4d56bc8978e042e72f9Chris Lattner} 18852c09d76564d6fb24444c4d56bc8978e042e72f9Chris Lattner 18952c09d76564d6fb24444c4d56bc8978e042e72f9Chris Lattnervoid MachineBasicBlock::removePredecessor(MachineBasicBlock *pred) { 190edf128a7fa90f2b0b7ee24741a04a7ae1ecd6f7eMisha Brukman std::vector<MachineBasicBlock *>::iterator I = 19152c09d76564d6fb24444c4d56bc8978e042e72f9Chris Lattner std::find(Predecessors.begin(), Predecessors.end(), pred); 19252c09d76564d6fb24444c4d56bc8978e042e72f9Chris Lattner assert(I != Predecessors.end() && "Pred is not a predecessor of this block!"); 19352c09d76564d6fb24444c4d56bc8978e042e72f9Chris Lattner Predecessors.erase(I); 19452c09d76564d6fb24444c4d56bc8978e042e72f9Chris Lattner} 1954f098788d303bed05da6000f3ff24177aad56623Evan Cheng 1964f098788d303bed05da6000f3ff24177aad56623Evan Chengbool MachineBasicBlock::isSuccessor(MachineBasicBlock *MBB) const { 1974f098788d303bed05da6000f3ff24177aad56623Evan Cheng std::vector<MachineBasicBlock *>::const_iterator I = 1984f098788d303bed05da6000f3ff24177aad56623Evan Cheng std::find(Successors.begin(), Successors.end(), MBB); 1994f098788d303bed05da6000f3ff24177aad56623Evan Cheng return I != Successors.end(); 2004f098788d303bed05da6000f3ff24177aad56623Evan Cheng} 2010370fad74b48388412c52d1325512f2c218487faEvan Cheng 2020370fad74b48388412c52d1325512f2c218487faEvan Cheng/// ReplaceUsesOfBlockWith - Given a machine basic block that branched to 2030370fad74b48388412c52d1325512f2c218487faEvan Cheng/// 'Old', change the code and CFG so that it branches to 'New' instead. 2040370fad74b48388412c52d1325512f2c218487faEvan Chengvoid MachineBasicBlock::ReplaceUsesOfBlockWith(MachineBasicBlock *Old, 2050370fad74b48388412c52d1325512f2c218487faEvan Cheng MachineBasicBlock *New) { 2060370fad74b48388412c52d1325512f2c218487faEvan Cheng assert(Old != New && "Cannot replace self with self!"); 2070370fad74b48388412c52d1325512f2c218487faEvan Cheng 2080370fad74b48388412c52d1325512f2c218487faEvan Cheng MachineBasicBlock::iterator I = end(); 2090370fad74b48388412c52d1325512f2c218487faEvan Cheng while (I != begin()) { 2100370fad74b48388412c52d1325512f2c218487faEvan Cheng --I; 2110370fad74b48388412c52d1325512f2c218487faEvan Cheng if (!(I->getInstrDescriptor()->Flags & M_TERMINATOR_FLAG)) break; 2120370fad74b48388412c52d1325512f2c218487faEvan Cheng 2130370fad74b48388412c52d1325512f2c218487faEvan Cheng // Scan the operands of this machine instruction, replacing any uses of Old 2140370fad74b48388412c52d1325512f2c218487faEvan Cheng // with New. 2150370fad74b48388412c52d1325512f2c218487faEvan Cheng for (unsigned i = 0, e = I->getNumOperands(); i != e; ++i) 2160370fad74b48388412c52d1325512f2c218487faEvan Cheng if (I->getOperand(i).isMachineBasicBlock() && 2170370fad74b48388412c52d1325512f2c218487faEvan Cheng I->getOperand(i).getMachineBasicBlock() == Old) 2180370fad74b48388412c52d1325512f2c218487faEvan Cheng I->getOperand(i).setMachineBasicBlock(New); 2190370fad74b48388412c52d1325512f2c218487faEvan Cheng } 2200370fad74b48388412c52d1325512f2c218487faEvan Cheng 2210370fad74b48388412c52d1325512f2c218487faEvan Cheng // Update the successor information. If New was already a successor, just 2220370fad74b48388412c52d1325512f2c218487faEvan Cheng // remove the link to Old instead of creating another one. PR 1444. 2230370fad74b48388412c52d1325512f2c218487faEvan Cheng removeSuccessor(Old); 2240370fad74b48388412c52d1325512f2c218487faEvan Cheng if (!isSuccessor(New)) 2250370fad74b48388412c52d1325512f2c218487faEvan Cheng addSuccessor(New); 2260370fad74b48388412c52d1325512f2c218487faEvan Cheng} 2270370fad74b48388412c52d1325512f2c218487faEvan Cheng 228