2004-02-16 07:17:43 +00:00
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//===-- llvm/CodeGen/MachineBasicBlock.cpp ----------------------*- C++ -*-===//
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//
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// The LLVM Compiler Infrastructure
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//
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2007-12-29 20:36:04 +00:00
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// This file is distributed under the University of Illinois Open Source
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// License. See LICENSE.TXT for details.
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2004-02-16 07:17:43 +00:00
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//
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//===----------------------------------------------------------------------===//
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//
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// Collect the sequence of machine instructions for a basic block.
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//
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//===----------------------------------------------------------------------===//
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#include "llvm/CodeGen/MachineBasicBlock.h"
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#include "llvm/BasicBlock.h"
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#include "llvm/CodeGen/MachineFunction.h"
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2010-01-26 04:55:51 +00:00
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#include "llvm/MC/MCAsmInfo.h"
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#include "llvm/MC/MCContext.h"
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2009-12-15 00:39:24 +00:00
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#include "llvm/Target/TargetRegisterInfo.h"
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2006-05-12 06:33:49 +00:00
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#include "llvm/Target/TargetData.h"
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2008-01-07 07:42:25 +00:00
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#include "llvm/Target/TargetInstrDesc.h"
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2009-11-12 03:55:33 +00:00
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#include "llvm/Target/TargetInstrInfo.h"
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2004-02-23 18:14:48 +00:00
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#include "llvm/Target/TargetMachine.h"
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2010-01-26 04:55:51 +00:00
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#include "llvm/Assembly/Writer.h"
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#include "llvm/ADT/SmallString.h"
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2010-01-04 23:22:07 +00:00
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#include "llvm/Support/Debug.h"
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2008-07-17 23:49:46 +00:00
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#include "llvm/Support/LeakDetector.h"
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2009-07-24 10:36:58 +00:00
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#include "llvm/Support/raw_ostream.h"
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2004-10-26 15:43:42 +00:00
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#include <algorithm>
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2004-02-16 07:17:43 +00:00
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using namespace llvm;
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2008-07-07 23:14:23 +00:00
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MachineBasicBlock::MachineBasicBlock(MachineFunction &mf, const BasicBlock *bb)
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2009-10-30 01:27:03 +00:00
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: BB(bb), Number(-1), xParent(&mf), Alignment(0), IsLandingPad(false),
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AddressTaken(false) {
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2008-07-28 21:51:04 +00:00
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Insts.Parent = this;
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2004-05-24 07:14:35 +00:00
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}
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2008-07-17 23:49:46 +00:00
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MachineBasicBlock::~MachineBasicBlock() {
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LeakDetector::removeGarbageObject(this);
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}
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2010-01-26 04:55:51 +00:00
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/// getSymbol - Return the MCSymbol for this basic block.
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///
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2010-03-13 21:04:28 +00:00
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MCSymbol *MachineBasicBlock::getSymbol() const {
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2010-01-26 04:55:51 +00:00
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const MachineFunction *MF = getParent();
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2010-03-13 21:04:28 +00:00
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MCContext &Ctx = MF->getContext();
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const char *Prefix = Ctx.getAsmInfo().getPrivateGlobalPrefix();
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2010-03-30 18:10:53 +00:00
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return Ctx.GetOrCreateSymbol(Twine(Prefix) + "BB" +
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Twine(MF->getFunctionNumber()) + "_" +
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Twine(getNumber()));
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2010-01-26 04:55:51 +00:00
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}
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2009-08-23 00:35:30 +00:00
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raw_ostream &llvm::operator<<(raw_ostream &OS, const MachineBasicBlock &MBB) {
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2009-07-24 10:36:58 +00:00
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MBB.print(OS);
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return OS;
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}
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2004-05-24 07:14:35 +00:00
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2008-01-01 01:12:31 +00:00
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/// addNodeToList (MBB) - When an MBB is added to an MF, we need to update the
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/// parent pointer of the MBB, the MBB numbering, and any instructions in the
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/// MBB to be on the right operand list for registers.
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///
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/// MBBs start out as #-1. When a MBB is added to a MachineFunction, it
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/// gets the next available unique MBB number. If it is removed from a
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/// MachineFunction, it goes back to being #-1.
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2009-08-23 00:35:30 +00:00
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void ilist_traits<MachineBasicBlock>::addNodeToList(MachineBasicBlock *N) {
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2008-07-07 23:14:23 +00:00
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MachineFunction &MF = *N->getParent();
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N->Number = MF.addToMBBNumbering(N);
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2008-01-01 01:12:31 +00:00
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// Make sure the instructions have their operands in the reginfo lists.
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2008-07-07 23:14:23 +00:00
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MachineRegisterInfo &RegInfo = MF.getRegInfo();
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2008-01-01 01:12:31 +00:00
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for (MachineBasicBlock::iterator I = N->begin(), E = N->end(); I != E; ++I)
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I->AddRegOperandsToUseLists(RegInfo);
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2008-07-17 23:49:46 +00:00
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LeakDetector::removeGarbageObject(N);
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2004-05-12 21:35:22 +00:00
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}
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2009-08-23 00:35:30 +00:00
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void ilist_traits<MachineBasicBlock>::removeNodeFromList(MachineBasicBlock *N) {
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2007-12-31 04:56:33 +00:00
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N->getParent()->removeFromMBBNumbering(N->Number);
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2004-05-12 21:35:22 +00:00
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N->Number = -1;
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2008-07-17 23:49:46 +00:00
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LeakDetector::addGarbageObject(N);
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2004-05-12 21:35:22 +00:00
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}
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2004-02-19 16:13:54 +00:00
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2008-01-01 01:12:31 +00:00
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/// addNodeToList (MI) - When we add an instruction to a basic block
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/// list, we update its parent pointer and add its operands from reg use/def
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/// lists if appropriate.
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2009-08-23 00:35:30 +00:00
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void ilist_traits<MachineInstr>::addNodeToList(MachineInstr *N) {
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2007-12-31 04:56:33 +00:00
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assert(N->getParent() == 0 && "machine instruction already in a basic block");
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2008-07-07 23:14:23 +00:00
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N->setParent(Parent);
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2008-01-01 01:12:31 +00:00
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2008-07-07 23:14:23 +00:00
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// Add the instruction's register operands to their corresponding
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// use/def lists.
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MachineFunction *MF = Parent->getParent();
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N->AddRegOperandsToUseLists(MF->getRegInfo());
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2008-07-17 23:49:46 +00:00
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LeakDetector::removeGarbageObject(N);
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2004-02-16 07:17:43 +00:00
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}
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2008-01-01 01:12:31 +00:00
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/// removeNodeFromList (MI) - When we remove an instruction from a basic block
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/// list, we update its parent pointer and remove its operands from reg use/def
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/// lists if appropriate.
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2009-08-23 00:35:30 +00:00
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void ilist_traits<MachineInstr>::removeNodeFromList(MachineInstr *N) {
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2007-12-31 04:56:33 +00:00
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assert(N->getParent() != 0 && "machine instruction not in a basic block");
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2008-07-07 23:14:23 +00:00
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// Remove from the use/def lists.
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N->RemoveRegOperandsFromUseLists();
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2008-01-01 01:12:31 +00:00
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2007-12-31 04:56:33 +00:00
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N->setParent(0);
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2008-07-17 23:49:46 +00:00
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LeakDetector::addGarbageObject(N);
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2004-02-16 07:17:43 +00:00
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}
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2008-01-01 01:12:31 +00:00
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/// transferNodesFromList (MI) - When moving a range of instructions from one
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/// MBB list to another, we need to update the parent pointers and the use/def
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/// lists.
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2009-08-23 00:35:30 +00:00
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void ilist_traits<MachineInstr>::
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transferNodesFromList(ilist_traits<MachineInstr> &fromList,
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MachineBasicBlock::iterator first,
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MachineBasicBlock::iterator last) {
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2008-07-28 21:51:04 +00:00
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assert(Parent->getParent() == fromList.Parent->getParent() &&
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"MachineInstr parent mismatch!");
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2007-12-31 04:56:33 +00:00
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// Splice within the same MBB -> no change.
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2008-07-07 23:14:23 +00:00
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if (Parent == fromList.Parent) return;
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2008-01-01 01:12:31 +00:00
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// If splicing between two blocks within the same function, just update the
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// parent pointers.
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2008-07-28 21:51:04 +00:00
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for (; first != last; ++first)
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2008-07-07 23:14:23 +00:00
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first->setParent(Parent);
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2004-02-16 07:17:43 +00:00
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}
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2008-07-28 21:51:04 +00:00
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void ilist_traits<MachineInstr>::deleteNode(MachineInstr* MI) {
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2008-07-07 23:14:23 +00:00
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assert(!MI->getParent() && "MI is still in a block!");
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Parent->getParent()->DeleteMachineInstr(MI);
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}
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2004-10-26 15:43:42 +00:00
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MachineBasicBlock::iterator MachineBasicBlock::getFirstTerminator() {
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2004-02-23 18:14:48 +00:00
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iterator I = end();
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2008-01-07 07:27:27 +00:00
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while (I != begin() && (--I)->getDesc().isTerminator())
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2007-09-02 22:11:14 +00:00
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; /*noop */
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2008-01-07 07:27:27 +00:00
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if (I != end() && !I->getDesc().isTerminator()) ++I;
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2004-02-23 18:14:48 +00:00
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return I;
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}
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2004-10-26 15:43:42 +00:00
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void MachineBasicBlock::dump() const {
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2010-01-04 23:22:07 +00:00
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print(dbgs());
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2004-02-16 07:17:43 +00:00
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}
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2009-07-24 10:36:58 +00:00
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static inline void OutputReg(raw_ostream &os, unsigned RegNo,
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2008-02-10 18:45:23 +00:00
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const TargetRegisterInfo *TRI = 0) {
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2009-10-31 20:19:03 +00:00
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if (RegNo != 0 && TargetRegisterInfo::isPhysicalRegister(RegNo)) {
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2008-02-10 18:45:23 +00:00
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if (TRI)
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2008-02-26 21:47:57 +00:00
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os << " %" << TRI->get(RegNo).Name;
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2007-02-10 02:38:19 +00:00
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else
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2009-10-31 20:19:03 +00:00
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os << " %physreg" << RegNo;
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2007-02-10 02:38:19 +00:00
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} else
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os << " %reg" << RegNo;
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}
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2009-11-20 01:17:03 +00:00
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StringRef MachineBasicBlock::getName() const {
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if (const BasicBlock *LBB = getBasicBlock())
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return LBB->getName();
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else
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return "(null)";
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}
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2009-08-23 00:47:04 +00:00
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void MachineBasicBlock::print(raw_ostream &OS) const {
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2007-02-10 02:38:19 +00:00
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const MachineFunction *MF = getParent();
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2009-08-23 00:35:30 +00:00
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if (!MF) {
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2004-10-26 15:43:42 +00:00
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OS << "Can't print out MachineBasicBlock because parent MachineFunction"
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<< " is null\n";
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2004-05-24 06:11:51 +00:00
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return;
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}
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2004-09-05 18:39:20 +00:00
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2009-10-31 20:19:03 +00:00
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if (Alignment) { OS << "Alignment " << Alignment << "\n"; }
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OS << "BB#" << getNumber() << ": ";
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const char *Comma = "";
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if (const BasicBlock *LBB = getBasicBlock()) {
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OS << Comma << "derived from LLVM BB ";
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WriteAsOperand(OS, LBB, /*PrintType=*/false);
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Comma = ", ";
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}
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if (isLandingPad()) { OS << Comma << "EH LANDING PAD"; Comma = ", "; }
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if (hasAddressTaken()) { OS << Comma << "ADDRESS TAKEN"; Comma = ", "; }
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2009-08-23 00:35:30 +00:00
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OS << '\n';
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2007-02-10 02:38:19 +00:00
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2008-02-10 18:45:23 +00:00
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const TargetRegisterInfo *TRI = MF->getTarget().getRegisterInfo();
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2007-10-03 19:26:29 +00:00
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if (!livein_empty()) {
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2009-10-31 20:19:03 +00:00
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OS << " Live Ins:";
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2007-02-19 21:49:54 +00:00
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for (const_livein_iterator I = livein_begin(),E = livein_end(); I != E; ++I)
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2008-02-10 18:45:23 +00:00
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OutputReg(OS, *I, TRI);
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2009-08-23 00:35:30 +00:00
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OS << '\n';
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2007-02-10 02:38:19 +00:00
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}
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2006-09-26 03:41:59 +00:00
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// Print the preds of this block according to the CFG.
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if (!pred_empty()) {
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OS << " Predecessors according to CFG:";
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for (const_pred_iterator PI = pred_begin(), E = pred_end(); PI != E; ++PI)
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2009-10-31 20:19:03 +00:00
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OS << " BB#" << (*PI)->getNumber();
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2009-08-23 00:35:30 +00:00
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OS << '\n';
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2006-09-26 03:41:59 +00:00
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}
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2004-09-05 18:39:20 +00:00
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for (const_iterator I = begin(); I != end(); ++I) {
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2009-08-23 00:47:04 +00:00
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OS << '\t';
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2004-09-05 18:39:20 +00:00
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I->print(OS, &getParent()->getTarget());
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}
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2005-04-01 06:48:38 +00:00
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// Print the successors of this block according to the CFG.
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if (!succ_empty()) {
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OS << " Successors according to CFG:";
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for (const_succ_iterator SI = succ_begin(), E = succ_end(); SI != E; ++SI)
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2009-10-31 20:19:03 +00:00
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OS << " BB#" << (*SI)->getNumber();
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2009-08-23 00:35:30 +00:00
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OS << '\n';
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2005-04-01 06:48:38 +00:00
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}
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2004-02-16 07:17:43 +00:00
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}
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2004-10-26 15:43:42 +00:00
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2007-02-19 21:49:54 +00:00
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void MachineBasicBlock::removeLiveIn(unsigned Reg) {
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livein_iterator I = std::find(livein_begin(), livein_end(), Reg);
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assert(I != livein_end() && "Not a live in!");
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LiveIns.erase(I);
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}
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2008-04-24 09:06:33 +00:00
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bool MachineBasicBlock::isLiveIn(unsigned Reg) const {
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const_livein_iterator I = std::find(livein_begin(), livein_end(), Reg);
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return I != livein_end();
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}
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2006-10-24 00:02:26 +00:00
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void MachineBasicBlock::moveBefore(MachineBasicBlock *NewAfter) {
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2008-07-07 23:14:23 +00:00
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getParent()->splice(NewAfter, this);
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2006-10-24 00:02:26 +00:00
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}
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void MachineBasicBlock::moveAfter(MachineBasicBlock *NewBefore) {
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MachineFunction::iterator BBI = NewBefore;
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2008-07-07 23:14:23 +00:00
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getParent()->splice(++BBI, this);
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2006-10-24 00:02:26 +00:00
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}
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2009-11-12 03:55:33 +00:00
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void MachineBasicBlock::updateTerminator() {
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const TargetInstrInfo *TII = getParent()->getTarget().getInstrInfo();
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// A block with no successors has no concerns with fall-through edges.
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if (this->succ_empty()) return;
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MachineBasicBlock *TBB = 0, *FBB = 0;
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SmallVector<MachineOperand, 4> Cond;
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bool B = TII->AnalyzeBranch(*this, TBB, FBB, Cond);
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(void) B;
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assert(!B && "UpdateTerminators requires analyzable predecessors!");
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if (Cond.empty()) {
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if (TBB) {
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// The block has an unconditional branch. If its successor is now
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// its layout successor, delete the branch.
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if (isLayoutSuccessor(TBB))
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TII->RemoveBranch(*this);
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} else {
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// The block has an unconditional fallthrough. If its successor is not
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// its layout successor, insert a branch.
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TBB = *succ_begin();
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if (!isLayoutSuccessor(TBB))
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TII->InsertBranch(*this, TBB, 0, Cond);
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}
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} else {
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if (FBB) {
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// The block has a non-fallthrough conditional branch. If one of its
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// successors is its layout successor, rewrite it to a fallthrough
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// conditional branch.
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if (isLayoutSuccessor(TBB)) {
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2009-11-22 18:28:04 +00:00
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if (TII->ReverseBranchCondition(Cond))
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return;
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2009-11-12 03:55:33 +00:00
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TII->RemoveBranch(*this);
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|
TII->InsertBranch(*this, FBB, 0, Cond);
|
|
|
|
} else if (isLayoutSuccessor(FBB)) {
|
|
|
|
TII->RemoveBranch(*this);
|
|
|
|
TII->InsertBranch(*this, TBB, 0, Cond);
|
|
|
|
}
|
|
|
|
} else {
|
|
|
|
// The block has a fallthrough conditional branch.
|
|
|
|
MachineBasicBlock *MBBA = *succ_begin();
|
2009-12-03 00:50:42 +00:00
|
|
|
MachineBasicBlock *MBBB = *llvm::next(succ_begin());
|
2009-11-12 03:55:33 +00:00
|
|
|
if (MBBA == TBB) std::swap(MBBB, MBBA);
|
|
|
|
if (isLayoutSuccessor(TBB)) {
|
2009-11-22 18:28:04 +00:00
|
|
|
if (TII->ReverseBranchCondition(Cond)) {
|
|
|
|
// We can't reverse the condition, add an unconditional branch.
|
|
|
|
Cond.clear();
|
|
|
|
TII->InsertBranch(*this, MBBA, 0, Cond);
|
|
|
|
return;
|
|
|
|
}
|
2009-11-12 03:55:33 +00:00
|
|
|
TII->RemoveBranch(*this);
|
|
|
|
TII->InsertBranch(*this, MBBA, 0, Cond);
|
|
|
|
} else if (!isLayoutSuccessor(MBBA)) {
|
|
|
|
TII->RemoveBranch(*this);
|
|
|
|
TII->InsertBranch(*this, TBB, MBBA, Cond);
|
|
|
|
}
|
|
|
|
}
|
|
|
|
}
|
|
|
|
}
|
2006-10-24 00:02:26 +00:00
|
|
|
|
2004-10-26 15:43:42 +00:00
|
|
|
void MachineBasicBlock::addSuccessor(MachineBasicBlock *succ) {
|
|
|
|
Successors.push_back(succ);
|
|
|
|
succ->addPredecessor(this);
|
|
|
|
}
|
|
|
|
|
|
|
|
void MachineBasicBlock::removeSuccessor(MachineBasicBlock *succ) {
|
|
|
|
succ->removePredecessor(this);
|
|
|
|
succ_iterator I = std::find(Successors.begin(), Successors.end(), succ);
|
|
|
|
assert(I != Successors.end() && "Not a current successor!");
|
|
|
|
Successors.erase(I);
|
|
|
|
}
|
|
|
|
|
2007-12-31 04:56:33 +00:00
|
|
|
MachineBasicBlock::succ_iterator
|
|
|
|
MachineBasicBlock::removeSuccessor(succ_iterator I) {
|
2004-10-26 15:43:42 +00:00
|
|
|
assert(I != Successors.end() && "Not a current successor!");
|
|
|
|
(*I)->removePredecessor(this);
|
2009-01-08 22:19:34 +00:00
|
|
|
return Successors.erase(I);
|
2004-10-26 15:43:42 +00:00
|
|
|
}
|
|
|
|
|
|
|
|
void MachineBasicBlock::addPredecessor(MachineBasicBlock *pred) {
|
|
|
|
Predecessors.push_back(pred);
|
|
|
|
}
|
|
|
|
|
|
|
|
void MachineBasicBlock::removePredecessor(MachineBasicBlock *pred) {
|
2005-04-21 22:36:52 +00:00
|
|
|
std::vector<MachineBasicBlock *>::iterator I =
|
2004-10-26 15:43:42 +00:00
|
|
|
std::find(Predecessors.begin(), Predecessors.end(), pred);
|
|
|
|
assert(I != Predecessors.end() && "Pred is not a predecessor of this block!");
|
|
|
|
Predecessors.erase(I);
|
|
|
|
}
|
2007-05-17 23:58:53 +00:00
|
|
|
|
2009-08-23 00:35:30 +00:00
|
|
|
void MachineBasicBlock::transferSuccessors(MachineBasicBlock *fromMBB) {
|
2008-05-05 19:05:59 +00:00
|
|
|
if (this == fromMBB)
|
|
|
|
return;
|
|
|
|
|
2009-08-23 00:35:30 +00:00
|
|
|
for (MachineBasicBlock::succ_iterator I = fromMBB->succ_begin(),
|
|
|
|
E = fromMBB->succ_end(); I != E; ++I)
|
|
|
|
addSuccessor(*I);
|
|
|
|
|
|
|
|
while (!fromMBB->succ_empty())
|
2008-05-05 19:05:59 +00:00
|
|
|
fromMBB->removeSuccessor(fromMBB->succ_begin());
|
|
|
|
}
|
|
|
|
|
2009-03-30 20:06:29 +00:00
|
|
|
bool MachineBasicBlock::isSuccessor(const MachineBasicBlock *MBB) const {
|
2007-05-17 23:58:53 +00:00
|
|
|
std::vector<MachineBasicBlock *>::const_iterator I =
|
|
|
|
std::find(Successors.begin(), Successors.end(), MBB);
|
|
|
|
return I != Successors.end();
|
|
|
|
}
|
2007-06-04 06:44:01 +00:00
|
|
|
|
2009-03-30 20:06:29 +00:00
|
|
|
bool MachineBasicBlock::isLayoutSuccessor(const MachineBasicBlock *MBB) const {
|
2008-10-02 22:09:09 +00:00
|
|
|
MachineFunction::const_iterator I(this);
|
2009-12-03 00:50:42 +00:00
|
|
|
return llvm::next(I) == MachineFunction::const_iterator(MBB);
|
2008-10-02 22:09:09 +00:00
|
|
|
}
|
|
|
|
|
2009-11-26 00:32:21 +00:00
|
|
|
bool MachineBasicBlock::canFallThrough() {
|
|
|
|
MachineFunction::iterator Fallthrough = this;
|
|
|
|
++Fallthrough;
|
|
|
|
// If FallthroughBlock is off the end of the function, it can't fall through.
|
|
|
|
if (Fallthrough == getParent()->end())
|
|
|
|
return false;
|
|
|
|
|
|
|
|
// If FallthroughBlock isn't a successor, no fallthrough is possible.
|
|
|
|
if (!isSuccessor(Fallthrough))
|
|
|
|
return false;
|
|
|
|
|
2009-12-05 00:32:59 +00:00
|
|
|
// Analyze the branches, if any, at the end of the block.
|
|
|
|
MachineBasicBlock *TBB = 0, *FBB = 0;
|
|
|
|
SmallVector<MachineOperand, 4> Cond;
|
|
|
|
const TargetInstrInfo *TII = getParent()->getTarget().getInstrInfo();
|
2010-01-15 20:00:12 +00:00
|
|
|
if (TII->AnalyzeBranch(*this, TBB, FBB, Cond)) {
|
2009-12-05 00:32:59 +00:00
|
|
|
// If we couldn't analyze the branch, examine the last instruction.
|
|
|
|
// If the block doesn't end in a known control barrier, assume fallthrough
|
|
|
|
// is possible. The isPredicable check is needed because this code can be
|
|
|
|
// called during IfConversion, where an instruction which is normally a
|
|
|
|
// Barrier is predicated and thus no longer an actual control barrier. This
|
|
|
|
// is over-conservative though, because if an instruction isn't actually
|
|
|
|
// predicated we could still treat it like a barrier.
|
2009-11-26 00:32:21 +00:00
|
|
|
return empty() || !back().getDesc().isBarrier() ||
|
|
|
|
back().getDesc().isPredicable();
|
2009-12-05 00:32:59 +00:00
|
|
|
}
|
2009-11-26 00:32:21 +00:00
|
|
|
|
|
|
|
// If there is no branch, control always falls through.
|
|
|
|
if (TBB == 0) return true;
|
|
|
|
|
|
|
|
// If there is some explicit branch to the fallthrough block, it can obviously
|
|
|
|
// reach, even though the branch should get folded to fall through implicitly.
|
|
|
|
if (MachineFunction::iterator(TBB) == Fallthrough ||
|
|
|
|
MachineFunction::iterator(FBB) == Fallthrough)
|
|
|
|
return true;
|
|
|
|
|
|
|
|
// If it's an unconditional branch to some block not the fall through, it
|
|
|
|
// doesn't fall through.
|
|
|
|
if (Cond.empty()) return false;
|
|
|
|
|
|
|
|
// Otherwise, if it is conditional and has no explicit false block, it falls
|
|
|
|
// through.
|
|
|
|
return FBB == 0;
|
|
|
|
}
|
|
|
|
|
2008-07-07 23:14:23 +00:00
|
|
|
/// removeFromParent - This method unlinks 'this' from the containing function,
|
|
|
|
/// and returns it, but does not delete it.
|
|
|
|
MachineBasicBlock *MachineBasicBlock::removeFromParent() {
|
|
|
|
assert(getParent() && "Not embedded in a function!");
|
|
|
|
getParent()->remove(this);
|
|
|
|
return this;
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
|
|
/// eraseFromParent - This method unlinks 'this' from the containing function,
|
|
|
|
/// and deletes it.
|
|
|
|
void MachineBasicBlock::eraseFromParent() {
|
|
|
|
assert(getParent() && "Not embedded in a function!");
|
|
|
|
getParent()->erase(this);
|
|
|
|
}
|
|
|
|
|
|
|
|
|
2007-06-04 06:44:01 +00:00
|
|
|
/// ReplaceUsesOfBlockWith - Given a machine basic block that branched to
|
|
|
|
/// 'Old', change the code and CFG so that it branches to 'New' instead.
|
|
|
|
void MachineBasicBlock::ReplaceUsesOfBlockWith(MachineBasicBlock *Old,
|
|
|
|
MachineBasicBlock *New) {
|
|
|
|
assert(Old != New && "Cannot replace self with self!");
|
|
|
|
|
|
|
|
MachineBasicBlock::iterator I = end();
|
|
|
|
while (I != begin()) {
|
|
|
|
--I;
|
2008-01-07 07:27:27 +00:00
|
|
|
if (!I->getDesc().isTerminator()) break;
|
2007-06-04 06:44:01 +00:00
|
|
|
|
|
|
|
// Scan the operands of this machine instruction, replacing any uses of Old
|
|
|
|
// with New.
|
|
|
|
for (unsigned i = 0, e = I->getNumOperands(); i != e; ++i)
|
2008-10-03 15:45:36 +00:00
|
|
|
if (I->getOperand(i).isMBB() &&
|
2008-09-13 17:58:21 +00:00
|
|
|
I->getOperand(i).getMBB() == Old)
|
2007-12-30 23:10:15 +00:00
|
|
|
I->getOperand(i).setMBB(New);
|
2007-06-04 06:44:01 +00:00
|
|
|
}
|
|
|
|
|
2009-05-05 21:10:19 +00:00
|
|
|
// Update the successor information.
|
2007-06-04 06:44:01 +00:00
|
|
|
removeSuccessor(Old);
|
2009-05-05 21:10:19 +00:00
|
|
|
addSuccessor(New);
|
2007-06-04 06:44:01 +00:00
|
|
|
}
|
|
|
|
|
2007-06-18 22:43:58 +00:00
|
|
|
/// CorrectExtraCFGEdges - Various pieces of code can cause excess edges in the
|
|
|
|
/// CFG to be inserted. If we have proven that MBB can only branch to DestA and
|
2009-12-16 00:08:36 +00:00
|
|
|
/// DestB, remove any other MBB successors from the CFG. DestA and DestB can be
|
|
|
|
/// null.
|
|
|
|
///
|
2007-12-31 04:56:33 +00:00
|
|
|
/// Besides DestA and DestB, retain other edges leading to LandingPads
|
|
|
|
/// (currently there can be only one; we don't check or require that here).
|
2007-06-18 22:43:58 +00:00
|
|
|
/// Note it is possible that DestA and/or DestB are LandingPads.
|
|
|
|
bool MachineBasicBlock::CorrectExtraCFGEdges(MachineBasicBlock *DestA,
|
|
|
|
MachineBasicBlock *DestB,
|
|
|
|
bool isCond) {
|
2009-12-16 00:08:36 +00:00
|
|
|
// The values of DestA and DestB frequently come from a call to the
|
|
|
|
// 'TargetInstrInfo::AnalyzeBranch' method. We take our meaning of the initial
|
|
|
|
// values from there.
|
|
|
|
//
|
|
|
|
// 1. If both DestA and DestB are null, then the block ends with no branches
|
|
|
|
// (it falls through to its successor).
|
|
|
|
// 2. If DestA is set, DestB is null, and isCond is false, then the block ends
|
|
|
|
// with only an unconditional branch.
|
|
|
|
// 3. If DestA is set, DestB is null, and isCond is true, then the block ends
|
|
|
|
// with a conditional branch that falls through to a successor (DestB).
|
|
|
|
// 4. If DestA and DestB is set and isCond is true, then the block ends with a
|
|
|
|
// conditional branch followed by an unconditional branch. DestA is the
|
|
|
|
// 'true' destination and DestB is the 'false' destination.
|
|
|
|
|
2007-06-18 22:43:58 +00:00
|
|
|
bool MadeChange = false;
|
|
|
|
bool AddedFallThrough = false;
|
|
|
|
|
2009-12-03 00:50:42 +00:00
|
|
|
MachineFunction::iterator FallThru =
|
|
|
|
llvm::next(MachineFunction::iterator(this));
|
2007-06-18 22:43:58 +00:00
|
|
|
|
|
|
|
if (isCond) {
|
2009-12-14 06:51:19 +00:00
|
|
|
// If this block ends with a conditional branch that falls through to its
|
|
|
|
// successor, set DestB as the successor.
|
2007-06-18 22:43:58 +00:00
|
|
|
if (DestB == 0 && FallThru != getParent()->end()) {
|
|
|
|
DestB = FallThru;
|
|
|
|
AddedFallThrough = true;
|
|
|
|
}
|
|
|
|
} else {
|
|
|
|
// If this is an unconditional branch with no explicit dest, it must just be
|
2009-12-14 06:51:19 +00:00
|
|
|
// a fallthrough into DestA.
|
2007-06-18 22:43:58 +00:00
|
|
|
if (DestA == 0 && FallThru != getParent()->end()) {
|
|
|
|
DestA = FallThru;
|
|
|
|
AddedFallThrough = true;
|
|
|
|
}
|
|
|
|
}
|
|
|
|
|
|
|
|
MachineBasicBlock::succ_iterator SI = succ_begin();
|
2009-12-15 00:39:24 +00:00
|
|
|
MachineBasicBlock *OrigDestA = DestA, *OrigDestB = DestB;
|
2007-06-18 22:43:58 +00:00
|
|
|
while (SI != succ_end()) {
|
2009-12-16 00:08:36 +00:00
|
|
|
const MachineBasicBlock *MBB = *SI;
|
|
|
|
if (MBB == DestA) {
|
2007-06-18 22:43:58 +00:00
|
|
|
DestA = 0;
|
|
|
|
++SI;
|
2009-12-16 00:08:36 +00:00
|
|
|
} else if (MBB == DestB) {
|
2007-06-18 22:43:58 +00:00
|
|
|
DestB = 0;
|
|
|
|
++SI;
|
2009-12-16 00:08:36 +00:00
|
|
|
} else if (MBB->isLandingPad() &&
|
|
|
|
MBB != OrigDestA && MBB != OrigDestB) {
|
2007-06-18 22:43:58 +00:00
|
|
|
++SI;
|
|
|
|
} else {
|
|
|
|
// Otherwise, this is a superfluous edge, remove it.
|
2007-06-29 02:45:24 +00:00
|
|
|
SI = removeSuccessor(SI);
|
2007-06-18 22:43:58 +00:00
|
|
|
MadeChange = true;
|
|
|
|
}
|
|
|
|
}
|
2009-12-16 00:08:36 +00:00
|
|
|
|
|
|
|
if (!AddedFallThrough)
|
|
|
|
assert(DestA == 0 && DestB == 0 && "MachineCFG is missing edges!");
|
|
|
|
else if (isCond)
|
2007-06-18 22:43:58 +00:00
|
|
|
assert(DestA == 0 && "MachineCFG is missing edges!");
|
2009-12-16 00:08:36 +00:00
|
|
|
|
2007-06-18 22:43:58 +00:00
|
|
|
return MadeChange;
|
|
|
|
}
|
2009-11-17 19:19:59 +00:00
|
|
|
|
2010-01-20 00:19:24 +00:00
|
|
|
/// findDebugLoc - find the next valid DebugLoc starting at MBBI, skipping
|
2010-02-10 00:11:11 +00:00
|
|
|
/// any DBG_VALUE instructions. Return UnknownLoc if there is none.
|
2010-01-20 00:19:24 +00:00
|
|
|
DebugLoc
|
2010-01-20 21:36:02 +00:00
|
|
|
MachineBasicBlock::findDebugLoc(MachineBasicBlock::iterator &MBBI) {
|
2010-01-20 00:19:24 +00:00
|
|
|
DebugLoc DL;
|
2010-01-20 21:36:02 +00:00
|
|
|
MachineBasicBlock::iterator E = end();
|
|
|
|
if (MBBI != E) {
|
2010-01-20 00:19:24 +00:00
|
|
|
// Skip debug declarations, we don't want a DebugLoc from them.
|
|
|
|
MachineBasicBlock::iterator MBBI2 = MBBI;
|
2010-02-09 19:54:29 +00:00
|
|
|
while (MBBI2 != E && MBBI2->isDebugValue())
|
2010-01-20 00:19:24 +00:00
|
|
|
MBBI2++;
|
2010-01-20 21:36:02 +00:00
|
|
|
if (MBBI2 != E)
|
2010-01-20 00:19:24 +00:00
|
|
|
DL = MBBI2->getDebugLoc();
|
|
|
|
}
|
|
|
|
return DL;
|
|
|
|
}
|
2010-01-20 21:36:02 +00:00
|
|
|
|
|
|
|
void llvm::WriteAsOperand(raw_ostream &OS, const MachineBasicBlock *MBB,
|
|
|
|
bool t) {
|
|
|
|
OS << "BB#" << MBB->getNumber();
|
|
|
|
}
|
|
|
|
|