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-rw-r--r--lib/Target/ARM/ARMConstantIslandPass.cpp246
1 files changed, 96 insertions, 150 deletions
diff --git a/lib/Target/ARM/ARMConstantIslandPass.cpp b/lib/Target/ARM/ARMConstantIslandPass.cpp
index 5e97c4cb35e3..60e5d7bf6098 100644
--- a/lib/Target/ARM/ARMConstantIslandPass.cpp
+++ b/lib/Target/ARM/ARMConstantIslandPass.cpp
@@ -1,9 +1,8 @@
//===- ARMConstantIslandPass.cpp - ARM constant islands -------------------===//
//
-// The LLVM Compiler Infrastructure
-//
-// This file is distributed under the University of Illinois Open Source
-// License. See LICENSE.TXT for details.
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
//
@@ -98,7 +97,7 @@ namespace {
/// CPE - A constant pool entry that has been placed somewhere, which
/// tracks a list of users.
class ARMConstantIslands : public MachineFunctionPass {
- std::vector<BasicBlockInfo> BBInfo;
+ std::unique_ptr<ARMBasicBlockUtils> BBUtils = nullptr;
/// WaterList - A sorted list of basic blocks where islands could be placed
/// (i.e. blocks that don't fall through to the following block, due
@@ -244,7 +243,6 @@ namespace {
void initializeFunctionInfo(const std::vector<MachineInstr*> &CPEMIs);
MachineBasicBlock *splitBlockBeforeInstr(MachineInstr *MI);
void updateForInsertedWaterBlock(MachineBasicBlock *NewBB);
- void adjustBBOffsetsAfter(MachineBasicBlock *BB);
bool decrementCPEReferenceCount(unsigned CPI, MachineInstr* CPEMI);
unsigned getCombinedIndex(const MachineInstr *CPEMI);
int findInRangeCPEntry(CPUser& U, unsigned UserOffset);
@@ -260,7 +258,6 @@ namespace {
bool DoDump = false);
bool isWaterInRange(unsigned UserOffset, MachineBasicBlock *Water,
CPUser &U, unsigned &Growth);
- bool isBBInRange(MachineInstr *MI, MachineBasicBlock *BB, unsigned Disp);
bool fixupImmediateBr(ImmBranch &Br);
bool fixupConditionalBr(ImmBranch &Br);
bool fixupUnconditionalBr(ImmBranch &Br);
@@ -275,7 +272,6 @@ namespace {
MachineBasicBlock *adjustJTTargetBlockForward(MachineBasicBlock *BB,
MachineBasicBlock *JTBB);
- unsigned getOffsetOf(MachineInstr *MI) const;
unsigned getUserOffset(CPUser&) const;
void dumpBBs();
void verify();
@@ -296,9 +292,10 @@ char ARMConstantIslands::ID = 0;
/// verify - check BBOffsets, BBSizes, alignment of islands
void ARMConstantIslands::verify() {
#ifndef NDEBUG
+ BBInfoVector &BBInfo = BBUtils->getBBInfo();
assert(std::is_sorted(MF->begin(), MF->end(),
- [this](const MachineBasicBlock &LHS,
- const MachineBasicBlock &RHS) {
+ [&BBInfo](const MachineBasicBlock &LHS,
+ const MachineBasicBlock &RHS) {
return BBInfo[LHS.getNumber()].postOffset() <
BBInfo[RHS.getNumber()].postOffset();
}));
@@ -324,6 +321,7 @@ void ARMConstantIslands::verify() {
#if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
/// print block size and offset information - debugging
LLVM_DUMP_METHOD void ARMConstantIslands::dumpBBs() {
+ BBInfoVector &BBInfo = BBUtils->getBBInfo();
LLVM_DEBUG({
for (unsigned J = 0, E = BBInfo.size(); J !=E; ++J) {
const BasicBlockInfo &BBI = BBInfo[J];
@@ -340,6 +338,7 @@ LLVM_DUMP_METHOD void ARMConstantIslands::dumpBBs() {
bool ARMConstantIslands::runOnMachineFunction(MachineFunction &mf) {
MF = &mf;
MCP = mf.getConstantPool();
+ BBUtils = std::unique_ptr<ARMBasicBlockUtils>(new ARMBasicBlockUtils(mf));
LLVM_DEBUG(dbgs() << "***** ARMConstantIslands: "
<< MCP->getConstants().size() << " CP entries, aligned to "
@@ -467,7 +466,7 @@ bool ARMConstantIslands::runOnMachineFunction(MachineFunction &mf) {
LLVM_DEBUG(dbgs() << '\n'; dumpBBs());
- BBInfo.clear();
+ BBUtils->clear();
WaterList.clear();
CPUsers.clear();
CPEntries.clear();
@@ -684,14 +683,14 @@ void ARMConstantIslands::scanFunctionJumpTables() {
void ARMConstantIslands::
initializeFunctionInfo(const std::vector<MachineInstr*> &CPEMIs) {
- BBInfo = computeAllBlockSizes(MF);
-
+ BBUtils->computeAllBlockSizes();
+ BBInfoVector &BBInfo = BBUtils->getBBInfo();
// The known bits of the entry block offset are determined by the function
// alignment.
BBInfo.front().KnownBits = MF->getAlignment();
// Compute block offsets and known bits.
- adjustBBOffsetsAfter(&MF->front());
+ BBUtils->adjustBBOffsetsAfter(&MF->front());
// Now go back through the instructions and build up our data structures.
for (MachineBasicBlock &MBB : *MF) {
@@ -856,25 +855,6 @@ initializeFunctionInfo(const std::vector<MachineInstr*> &CPEMIs) {
}
}
-/// getOffsetOf - Return the current offset of the specified machine instruction
-/// from the start of the function. This offset changes as stuff is moved
-/// around inside the function.
-unsigned ARMConstantIslands::getOffsetOf(MachineInstr *MI) const {
- MachineBasicBlock *MBB = MI->getParent();
-
- // The offset is composed of two things: the sum of the sizes of all MBB's
- // before this instruction's block, and the offset from the start of the block
- // it is in.
- unsigned Offset = BBInfo[MBB->getNumber()].Offset;
-
- // Sum instructions before MI in MBB.
- for (MachineBasicBlock::iterator I = MBB->begin(); &*I != MI; ++I) {
- assert(I != MBB->end() && "Didn't find MI in its own basic block?");
- Offset += TII->getInstSizeInBytes(*I);
- }
- return Offset;
-}
-
/// CompareMBBNumbers - Little predicate function to sort the WaterList by MBB
/// ID.
static bool CompareMBBNumbers(const MachineBasicBlock *LHS,
@@ -891,13 +871,11 @@ void ARMConstantIslands::updateForInsertedWaterBlock(MachineBasicBlock *NewBB) {
// Insert an entry into BBInfo to align it properly with the (newly
// renumbered) block numbers.
- BBInfo.insert(BBInfo.begin() + NewBB->getNumber(), BasicBlockInfo());
+ BBUtils->insert(NewBB->getNumber(), BasicBlockInfo());
// Next, update WaterList. Specifically, we need to add NewMBB as having
// available water after it.
- water_iterator IP =
- std::lower_bound(WaterList.begin(), WaterList.end(), NewBB,
- CompareMBBNumbers);
+ water_iterator IP = llvm::lower_bound(WaterList, NewBB, CompareMBBNumbers);
WaterList.insert(IP, NewBB);
}
@@ -942,15 +920,13 @@ MachineBasicBlock *ARMConstantIslands::splitBlockBeforeInstr(MachineInstr *MI) {
// Insert an entry into BBInfo to align it properly with the (newly
// renumbered) block numbers.
- BBInfo.insert(BBInfo.begin() + NewBB->getNumber(), BasicBlockInfo());
+ BBUtils->insert(NewBB->getNumber(), BasicBlockInfo());
// Next, update WaterList. Specifically, we need to add OrigMBB as having
// available water after it (but not if it's already there, which happens
// when splitting before a conditional branch that is followed by an
// unconditional branch - in that case we want to insert NewBB).
- water_iterator IP =
- std::lower_bound(WaterList.begin(), WaterList.end(), OrigBB,
- CompareMBBNumbers);
+ water_iterator IP = llvm::lower_bound(WaterList, OrigBB, CompareMBBNumbers);
MachineBasicBlock* WaterBB = *IP;
if (WaterBB == OrigBB)
WaterList.insert(std::next(IP), NewBB);
@@ -963,14 +939,14 @@ MachineBasicBlock *ARMConstantIslands::splitBlockBeforeInstr(MachineInstr *MI) {
// the new jump we added. (It should be possible to do this without
// recounting everything, but it's very confusing, and this is rarely
// executed.)
- computeBlockSize(MF, OrigBB, BBInfo[OrigBB->getNumber()]);
+ BBUtils->computeBlockSize(OrigBB);
// Figure out how large the NewMBB is. As the second half of the original
// block, it may contain a tablejump.
- computeBlockSize(MF, NewBB, BBInfo[NewBB->getNumber()]);
+ BBUtils->computeBlockSize(NewBB);
// All BBOffsets following these blocks must be modified.
- adjustBBOffsetsAfter(OrigBB);
+ BBUtils->adjustBBOffsetsAfter(OrigBB);
return NewBB;
}
@@ -979,7 +955,9 @@ MachineBasicBlock *ARMConstantIslands::splitBlockBeforeInstr(MachineInstr *MI) {
/// displacement computation. Update U.KnownAlignment to match its current
/// basic block location.
unsigned ARMConstantIslands::getUserOffset(CPUser &U) const {
- unsigned UserOffset = getOffsetOf(U.MI);
+ unsigned UserOffset = BBUtils->getOffsetOf(U.MI);
+
+ SmallVectorImpl<BasicBlockInfo> &BBInfo = BBUtils->getBBInfo();
const BasicBlockInfo &BBI = BBInfo[U.MI->getParent()->getNumber()];
unsigned KnownBits = BBI.internalKnownBits();
@@ -1028,6 +1006,7 @@ bool ARMConstantIslands::isOffsetInRange(unsigned UserOffset,
bool ARMConstantIslands::isWaterInRange(unsigned UserOffset,
MachineBasicBlock* Water, CPUser &U,
unsigned &Growth) {
+ BBInfoVector &BBInfo = BBUtils->getBBInfo();
unsigned CPELogAlign = getCPELogAlign(U.CPEMI);
unsigned CPEOffset = BBInfo[Water->getNumber()].postOffset(CPELogAlign);
unsigned NextBlockOffset, NextBlockAlignment;
@@ -1068,10 +1047,11 @@ bool ARMConstantIslands::isWaterInRange(unsigned UserOffset,
bool ARMConstantIslands::isCPEntryInRange(MachineInstr *MI, unsigned UserOffset,
MachineInstr *CPEMI, unsigned MaxDisp,
bool NegOk, bool DoDump) {
- unsigned CPEOffset = getOffsetOf(CPEMI);
+ unsigned CPEOffset = BBUtils->getOffsetOf(CPEMI);
if (DoDump) {
LLVM_DEBUG({
+ BBInfoVector &BBInfo = BBUtils->getBBInfo();
unsigned Block = MI->getParent()->getNumber();
const BasicBlockInfo &BBI = BBInfo[Block];
dbgs() << "User of CPE#" << CPEMI->getOperand(0).getImm()
@@ -1104,28 +1084,6 @@ static bool BBIsJumpedOver(MachineBasicBlock *MBB) {
}
#endif // NDEBUG
-void ARMConstantIslands::adjustBBOffsetsAfter(MachineBasicBlock *BB) {
- unsigned BBNum = BB->getNumber();
- for(unsigned i = BBNum + 1, e = MF->getNumBlockIDs(); i < e; ++i) {
- // Get the offset and known bits at the end of the layout predecessor.
- // Include the alignment of the current block.
- unsigned LogAlign = MF->getBlockNumbered(i)->getAlignment();
- unsigned Offset = BBInfo[i - 1].postOffset(LogAlign);
- unsigned KnownBits = BBInfo[i - 1].postKnownBits(LogAlign);
-
- // This is where block i begins. Stop if the offset is already correct,
- // and we have updated 2 blocks. This is the maximum number of blocks
- // changed before calling this function.
- if (i > BBNum + 2 &&
- BBInfo[i].Offset == Offset &&
- BBInfo[i].KnownBits == KnownBits)
- break;
-
- BBInfo[i].Offset = Offset;
- BBInfo[i].KnownBits = KnownBits;
- }
-}
-
/// decrementCPEReferenceCount - find the constant pool entry with index CPI
/// and instruction CPEMI, and decrement its refcount. If the refcount
/// becomes 0 remove the entry and instruction. Returns true if we removed
@@ -1241,6 +1199,7 @@ bool ARMConstantIslands::findAvailableWater(CPUser &U, unsigned UserOffset,
// When a CP access is out of range, BB0 may be used as water. However,
// inserting islands between BB0 and BB1 makes other accesses out of range.
MachineBasicBlock *UserBB = U.MI->getParent();
+ BBInfoVector &BBInfo = BBUtils->getBBInfo();
unsigned MinNoSplitDisp =
BBInfo[UserBB->getNumber()].postOffset(getCPELogAlign(U.CPEMI));
if (CloserWater && MinNoSplitDisp > U.getMaxDisp() / 2)
@@ -1297,6 +1256,7 @@ void ARMConstantIslands::createNewWater(unsigned CPUserIndex,
MachineInstr *CPEMI = U.CPEMI;
unsigned CPELogAlign = getCPELogAlign(CPEMI);
MachineBasicBlock *UserMBB = UserMI->getParent();
+ BBInfoVector &BBInfo = BBUtils->getBBInfo();
const BasicBlockInfo &UserBBI = BBInfo[UserMBB->getNumber()];
// If the block does not end in an unconditional branch already, and if the
@@ -1328,8 +1288,8 @@ void ARMConstantIslands::createNewWater(unsigned CPUserIndex,
unsigned MaxDisp = getUnconditionalBrDisp(UncondBr);
ImmBranches.push_back(ImmBranch(&UserMBB->back(),
MaxDisp, false, UncondBr));
- computeBlockSize(MF, UserMBB, BBInfo[UserMBB->getNumber()]);
- adjustBBOffsetsAfter(UserMBB);
+ BBUtils->computeBlockSize(UserMBB);
+ BBUtils->adjustBBOffsetsAfter(UserMBB);
return;
}
}
@@ -1538,8 +1498,8 @@ bool ARMConstantIslands::handleConstantPoolUser(unsigned CPUserIndex,
NewIsland->setAlignment(getCPELogAlign(U.CPEMI));
// Increase the size of the island block to account for the new entry.
- BBInfo[NewIsland->getNumber()].Size += Size;
- adjustBBOffsetsAfter(&*--NewIsland->getIterator());
+ BBUtils->adjustBBSize(NewIsland, Size);
+ BBUtils->adjustBBOffsetsAfter(&*--NewIsland->getIterator());
// Finally, change the CPI in the instruction operand to be ID.
for (unsigned i = 0, e = UserMI->getNumOperands(); i != e; ++i)
@@ -1550,7 +1510,8 @@ bool ARMConstantIslands::handleConstantPoolUser(unsigned CPUserIndex,
LLVM_DEBUG(
dbgs() << " Moved CPE to #" << ID << " CPI=" << CPI
- << format(" offset=%#x\n", BBInfo[NewIsland->getNumber()].Offset));
+ << format(" offset=%#x\n",
+ BBUtils->getBBInfo()[NewIsland->getNumber()].Offset));
return true;
}
@@ -1561,7 +1522,8 @@ void ARMConstantIslands::removeDeadCPEMI(MachineInstr *CPEMI) {
MachineBasicBlock *CPEBB = CPEMI->getParent();
unsigned Size = CPEMI->getOperand(2).getImm();
CPEMI->eraseFromParent();
- BBInfo[CPEBB->getNumber()].Size -= Size;
+ BBInfoVector &BBInfo = BBUtils->getBBInfo();
+ BBUtils->adjustBBSize(CPEBB, -Size);
// All succeeding offsets have the current size value added in, fix this.
if (CPEBB->empty()) {
BBInfo[CPEBB->getNumber()].Size = 0;
@@ -1572,7 +1534,7 @@ void ARMConstantIslands::removeDeadCPEMI(MachineInstr *CPEMI) {
// Entries are sorted by descending alignment, so realign from the front.
CPEBB->setAlignment(getCPELogAlign(&*CPEBB->begin()));
- adjustBBOffsetsAfter(CPEBB);
+ BBUtils->adjustBBOffsetsAfter(CPEBB);
// An island has only one predecessor BB and one successor BB. Check if
// this BB's predecessor jumps directly to this BB's successor. This
// shouldn't happen currently.
@@ -1597,30 +1559,6 @@ bool ARMConstantIslands::removeUnusedCPEntries() {
return MadeChange;
}
-/// isBBInRange - Returns true if the distance between specific MI and
-/// specific BB can fit in MI's displacement field.
-bool ARMConstantIslands::isBBInRange(MachineInstr *MI,MachineBasicBlock *DestBB,
- unsigned MaxDisp) {
- unsigned PCAdj = isThumb ? 4 : 8;
- unsigned BrOffset = getOffsetOf(MI) + PCAdj;
- unsigned DestOffset = BBInfo[DestBB->getNumber()].Offset;
-
- LLVM_DEBUG(dbgs() << "Branch of destination " << printMBBReference(*DestBB)
- << " from " << printMBBReference(*MI->getParent())
- << " max delta=" << MaxDisp << " from " << getOffsetOf(MI)
- << " to " << DestOffset << " offset "
- << int(DestOffset - BrOffset) << "\t" << *MI);
-
- if (BrOffset <= DestOffset) {
- // Branch before the Dest.
- if (DestOffset-BrOffset <= MaxDisp)
- return true;
- } else {
- if (BrOffset-DestOffset <= MaxDisp)
- return true;
- }
- return false;
-}
/// fixupImmediateBr - Fix up an immediate branch whose destination is too far
/// away to fit in its displacement field.
@@ -1629,7 +1567,7 @@ bool ARMConstantIslands::fixupImmediateBr(ImmBranch &Br) {
MachineBasicBlock *DestBB = MI->getOperand(0).getMBB();
// Check to see if the DestBB is already in-range.
- if (isBBInRange(MI, DestBB, Br.MaxDisp))
+ if (BBUtils->isBBInRange(MI, DestBB, Br.MaxDisp))
return false;
if (!Br.isCond)
@@ -1648,11 +1586,15 @@ ARMConstantIslands::fixupUnconditionalBr(ImmBranch &Br) {
if (!isThumb1)
llvm_unreachable("fixupUnconditionalBr is Thumb1 only!");
+ if (!AFI->isLRSpilled())
+ report_fatal_error("underestimated function size");
+
// Use BL to implement far jump.
Br.MaxDisp = (1 << 21) * 2;
MI->setDesc(TII->get(ARM::tBfar));
+ BBInfoVector &BBInfo = BBUtils->getBBInfo();
BBInfo[MBB->getNumber()].Size += 2;
- adjustBBOffsetsAfter(MBB);
+ BBUtils->adjustBBOffsetsAfter(MBB);
HasFarJump = true;
++NumUBrFixed;
@@ -1699,7 +1641,7 @@ ARMConstantIslands::fixupConditionalBr(ImmBranch &Br) {
// bne L2
// b L1
MachineBasicBlock *NewDest = BMI->getOperand(0).getMBB();
- if (isBBInRange(MI, NewDest, Br.MaxDisp)) {
+ if (BBUtils->isBBInRange(MI, NewDest, Br.MaxDisp)) {
LLVM_DEBUG(
dbgs() << " Invert Bcc condition and swap its destination with "
<< *BMI);
@@ -1716,7 +1658,7 @@ ARMConstantIslands::fixupConditionalBr(ImmBranch &Br) {
// No need for the branch to the next block. We're adding an unconditional
// branch to the destination.
int delta = TII->getInstSizeInBytes(MBB->back());
- BBInfo[MBB->getNumber()].Size -= delta;
+ BBUtils->adjustBBSize(MBB, -delta);
MBB->back().eraseFromParent();
// The conditional successor will be swapped between the BBs after this, so
@@ -1737,21 +1679,21 @@ ARMConstantIslands::fixupConditionalBr(ImmBranch &Br) {
BuildMI(MBB, DebugLoc(), TII->get(MI->getOpcode()))
.addMBB(NextBB).addImm(CC).addReg(CCReg);
Br.MI = &MBB->back();
- BBInfo[MBB->getNumber()].Size += TII->getInstSizeInBytes(MBB->back());
+ BBUtils->adjustBBSize(MBB, TII->getInstSizeInBytes(MBB->back()));
if (isThumb)
BuildMI(MBB, DebugLoc(), TII->get(Br.UncondBr))
.addMBB(DestBB)
.add(predOps(ARMCC::AL));
else
BuildMI(MBB, DebugLoc(), TII->get(Br.UncondBr)).addMBB(DestBB);
- BBInfo[MBB->getNumber()].Size += TII->getInstSizeInBytes(MBB->back());
+ BBUtils->adjustBBSize(MBB, TII->getInstSizeInBytes(MBB->back()));
unsigned MaxDisp = getUnconditionalBrDisp(Br.UncondBr);
ImmBranches.push_back(ImmBranch(&MBB->back(), MaxDisp, false, Br.UncondBr));
// Remove the old conditional branch. It may or may not still be in MBB.
- BBInfo[MI->getParent()->getNumber()].Size -= TII->getInstSizeInBytes(*MI);
+ BBUtils->adjustBBSize(MI->getParent(), -TII->getInstSizeInBytes(*MI));
MI->eraseFromParent();
- adjustBBOffsetsAfter(MBB);
+ BBUtils->adjustBBOffsetsAfter(MBB);
return true;
}
@@ -1826,8 +1768,8 @@ bool ARMConstantIslands::optimizeThumb2Instructions() {
LLVM_DEBUG(dbgs() << "Shrink: " << *U.MI);
U.MI->setDesc(TII->get(NewOpc));
MachineBasicBlock *MBB = U.MI->getParent();
- BBInfo[MBB->getNumber()].Size -= 2;
- adjustBBOffsetsAfter(MBB);
+ BBUtils->adjustBBSize(MBB, -2);
+ BBUtils->adjustBBOffsetsAfter(MBB);
++NumT2CPShrunk;
MadeChange = true;
}
@@ -1866,12 +1808,12 @@ bool ARMConstantIslands::optimizeThumb2Branches() {
if (NewOpc) {
unsigned MaxOffs = ((1 << (Bits-1))-1) * Scale;
MachineBasicBlock *DestBB = Br.MI->getOperand(0).getMBB();
- if (isBBInRange(Br.MI, DestBB, MaxOffs)) {
+ if (BBUtils->isBBInRange(Br.MI, DestBB, MaxOffs)) {
LLVM_DEBUG(dbgs() << "Shrink branch: " << *Br.MI);
Br.MI->setDesc(TII->get(NewOpc));
MachineBasicBlock *MBB = Br.MI->getParent();
- BBInfo[MBB->getNumber()].Size -= 2;
- adjustBBOffsetsAfter(MBB);
+ BBUtils->adjustBBSize(MBB, -2);
+ BBUtils->adjustBBOffsetsAfter(MBB);
++NumT2BrShrunk;
MadeChange = true;
}
@@ -1898,34 +1840,47 @@ bool ARMConstantIslands::optimizeThumb2Branches() {
MachineBasicBlock *DestBB = Br.MI->getOperand(0).getMBB();
// Check if the distance is within 126. Subtract starting offset by 2
// because the cmp will be eliminated.
- unsigned BrOffset = getOffsetOf(Br.MI) + 4 - 2;
+ unsigned BrOffset = BBUtils->getOffsetOf(Br.MI) + 4 - 2;
+ BBInfoVector &BBInfo = BBUtils->getBBInfo();
unsigned DestOffset = BBInfo[DestBB->getNumber()].Offset;
- if (BrOffset < DestOffset && (DestOffset - BrOffset) <= 126) {
- MachineBasicBlock::iterator CmpMI = Br.MI;
- if (CmpMI != Br.MI->getParent()->begin()) {
- --CmpMI;
- if (CmpMI->getOpcode() == ARM::tCMPi8) {
- unsigned Reg = CmpMI->getOperand(0).getReg();
- Pred = getInstrPredicate(*CmpMI, PredReg);
- if (Pred == ARMCC::AL &&
- CmpMI->getOperand(1).getImm() == 0 &&
- isARMLowRegister(Reg)) {
- MachineBasicBlock *MBB = Br.MI->getParent();
- LLVM_DEBUG(dbgs() << "Fold: " << *CmpMI << " and: " << *Br.MI);
- MachineInstr *NewBR =
- BuildMI(*MBB, CmpMI, Br.MI->getDebugLoc(), TII->get(NewOpc))
- .addReg(Reg).addMBB(DestBB,Br.MI->getOperand(0).getTargetFlags());
- CmpMI->eraseFromParent();
- Br.MI->eraseFromParent();
- Br.MI = NewBR;
- BBInfo[MBB->getNumber()].Size -= 2;
- adjustBBOffsetsAfter(MBB);
- ++NumCBZ;
- MadeChange = true;
- }
- }
+ if (BrOffset >= DestOffset || (DestOffset - BrOffset) > 126)
+ continue;
+
+ // Search backwards to find a tCMPi8
+ auto *TRI = STI->getRegisterInfo();
+ MachineInstr *CmpMI = findCMPToFoldIntoCBZ(Br.MI, TRI);
+ if (!CmpMI || CmpMI->getOpcode() != ARM::tCMPi8)
+ continue;
+
+ unsigned Reg = CmpMI->getOperand(0).getReg();
+
+ // Check for Kill flags on Reg. If they are present remove them and set kill
+ // on the new CBZ.
+ MachineBasicBlock::iterator KillMI = Br.MI;
+ bool RegKilled = false;
+ do {
+ --KillMI;
+ if (KillMI->killsRegister(Reg, TRI)) {
+ KillMI->clearRegisterKills(Reg, TRI);
+ RegKilled = true;
+ break;
}
- }
+ } while (KillMI != CmpMI);
+
+ // Create the new CBZ/CBNZ
+ MachineBasicBlock *MBB = Br.MI->getParent();
+ LLVM_DEBUG(dbgs() << "Fold: " << *CmpMI << " and: " << *Br.MI);
+ MachineInstr *NewBR =
+ BuildMI(*MBB, Br.MI, Br.MI->getDebugLoc(), TII->get(NewOpc))
+ .addReg(Reg, getKillRegState(RegKilled))
+ .addMBB(DestBB, Br.MI->getOperand(0).getTargetFlags());
+ CmpMI->eraseFromParent();
+ Br.MI->eraseFromParent();
+ Br.MI = NewBR;
+ BBInfo[MBB->getNumber()].Size -= 2;
+ BBUtils->adjustBBOffsetsAfter(MBB);
+ ++NumCBZ;
+ MadeChange = true;
}
return MadeChange;
@@ -2085,16 +2040,6 @@ static void RemoveDeadAddBetweenLEAAndJT(MachineInstr *LEAMI,
DeadSize += 4;
}
-static bool registerDefinedBetween(unsigned Reg,
- MachineBasicBlock::iterator From,
- MachineBasicBlock::iterator To,
- const TargetRegisterInfo *TRI) {
- for (auto I = From; I != To; ++I)
- if (I->modifiesRegister(Reg, TRI))
- return true;
- return false;
-}
-
/// optimizeThumb2JumpTables - Use tbb / tbh instructions to generate smaller
/// jumptables when it's possible.
bool ARMConstantIslands::optimizeThumb2JumpTables() {
@@ -2117,8 +2062,9 @@ bool ARMConstantIslands::optimizeThumb2JumpTables() {
bool ByteOk = true;
bool HalfWordOk = true;
- unsigned JTOffset = getOffsetOf(MI) + 4;
+ unsigned JTOffset = BBUtils->getOffsetOf(MI) + 4;
const std::vector<MachineBasicBlock*> &JTBBs = JT[JTI].MBBs;
+ BBInfoVector &BBInfo = BBUtils->getBBInfo();
for (unsigned j = 0, ee = JTBBs.size(); j != ee; ++j) {
MachineBasicBlock *MBB = JTBBs[j];
unsigned DstOffset = BBInfo[MBB->getNumber()].Offset;
@@ -2281,7 +2227,7 @@ bool ARMConstantIslands::optimizeThumb2JumpTables() {
int Delta = OrigSize - NewSize + DeadSize;
BBInfo[MBB->getNumber()].Size -= Delta;
- adjustBBOffsetsAfter(MBB);
+ BBUtils->adjustBBOffsetsAfter(MBB);
++NumTBs;
MadeChange = true;
generated by cgit v1.2.3 (git 2.25.1) at 2025-08-07 18:20:59 +0000