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Diffstat (limited to 'lib/CodeGen/MachineCopyPropagation.cpp')
-rw-r--r--lib/CodeGen/MachineCopyPropagation.cpp78
1 files changed, 46 insertions, 32 deletions
diff --git a/lib/CodeGen/MachineCopyPropagation.cpp b/lib/CodeGen/MachineCopyPropagation.cpp
index 9fc12ac89e12..ebe76e31dca9 100644
--- a/lib/CodeGen/MachineCopyPropagation.cpp
+++ b/lib/CodeGen/MachineCopyPropagation.cpp
@@ -119,8 +119,8 @@ public:
void trackCopy(MachineInstr *MI, const TargetRegisterInfo &TRI) {
assert(MI->isCopy() && "Tracking non-copy?");
- unsigned Def = MI->getOperand(0).getReg();
- unsigned Src = MI->getOperand(1).getReg();
+ Register Def = MI->getOperand(0).getReg();
+ Register Src = MI->getOperand(1).getReg();
// Remember Def is defined by the copy.
for (MCRegUnitIterator RUI(Def, &TRI); RUI.isValid(); ++RUI)
@@ -163,8 +163,8 @@ public:
// Check that the available copy isn't clobbered by any regmasks between
// itself and the destination.
- unsigned AvailSrc = AvailCopy->getOperand(1).getReg();
- unsigned AvailDef = AvailCopy->getOperand(0).getReg();
+ Register AvailSrc = AvailCopy->getOperand(1).getReg();
+ Register AvailDef = AvailCopy->getOperand(0).getReg();
for (const MachineInstr &MI :
make_range(AvailCopy->getIterator(), DestCopy.getIterator()))
for (const MachineOperand &MO : MI.operands())
@@ -205,8 +205,11 @@ public:
}
private:
+ typedef enum { DebugUse = false, RegularUse = true } DebugType;
+
void ClobberRegister(unsigned Reg);
- void ReadRegister(unsigned Reg);
+ void ReadRegister(unsigned Reg, MachineInstr &Reader,
+ DebugType DT);
void CopyPropagateBlock(MachineBasicBlock &MBB);
bool eraseIfRedundant(MachineInstr &Copy, unsigned Src, unsigned Def);
void forwardUses(MachineInstr &MI);
@@ -217,6 +220,9 @@ private:
/// Candidates for deletion.
SmallSetVector<MachineInstr *, 8> MaybeDeadCopies;
+ /// Multimap tracking debug users in current BB
+ DenseMap<MachineInstr*, SmallVector<MachineInstr*, 2>> CopyDbgUsers;
+
CopyTracker Tracker;
bool Changed;
@@ -231,13 +237,19 @@ char &llvm::MachineCopyPropagationID = MachineCopyPropagation::ID;
INITIALIZE_PASS(MachineCopyPropagation, DEBUG_TYPE,
"Machine Copy Propagation Pass", false, false)
-void MachineCopyPropagation::ReadRegister(unsigned Reg) {
+void MachineCopyPropagation::ReadRegister(unsigned Reg, MachineInstr &Reader,
+ DebugType DT) {
// If 'Reg' is defined by a copy, the copy is no longer a candidate
- // for elimination.
+ // for elimination. If a copy is "read" by a debug user, record the user
+ // for propagation.
for (MCRegUnitIterator RUI(Reg, TRI); RUI.isValid(); ++RUI) {
if (MachineInstr *Copy = Tracker.findCopyForUnit(*RUI, *TRI)) {
- LLVM_DEBUG(dbgs() << "MCP: Copy is used - not dead: "; Copy->dump());
- MaybeDeadCopies.remove(Copy);
+ if (DT == RegularUse) {
+ LLVM_DEBUG(dbgs() << "MCP: Copy is used - not dead: "; Copy->dump());
+ MaybeDeadCopies.remove(Copy);
+ } else {
+ CopyDbgUsers[Copy].push_back(&Reader);
+ }
}
}
}
@@ -250,8 +262,8 @@ void MachineCopyPropagation::ReadRegister(unsigned Reg) {
/// isNopCopy("ecx = COPY eax", AH, CL) == false
static bool isNopCopy(const MachineInstr &PreviousCopy, unsigned Src,
unsigned Def, const TargetRegisterInfo *TRI) {
- unsigned PreviousSrc = PreviousCopy.getOperand(1).getReg();
- unsigned PreviousDef = PreviousCopy.getOperand(0).getReg();
+ Register PreviousSrc = PreviousCopy.getOperand(1).getReg();
+ Register PreviousDef = PreviousCopy.getOperand(0).getReg();
if (Src == PreviousSrc) {
assert(Def == PreviousDef);
return true;
@@ -288,7 +300,7 @@ bool MachineCopyPropagation::eraseIfRedundant(MachineInstr &Copy, unsigned Src,
// Copy was redundantly redefining either Src or Def. Remove earlier kill
// flags between Copy and PrevCopy because the value will be reused now.
assert(Copy.isCopy());
- unsigned CopyDef = Copy.getOperand(0).getReg();
+ Register CopyDef = Copy.getOperand(0).getReg();
assert(CopyDef == Src || CopyDef == Def);
for (MachineInstr &MI :
make_range(PrevCopy->getIterator(), Copy.getIterator()))
@@ -307,7 +319,7 @@ bool MachineCopyPropagation::isForwardableRegClassCopy(const MachineInstr &Copy,
const MachineInstr &UseI,
unsigned UseIdx) {
- unsigned CopySrcReg = Copy.getOperand(1).getReg();
+ Register CopySrcReg = Copy.getOperand(1).getReg();
// If the new register meets the opcode register constraints, then allow
// forwarding.
@@ -398,9 +410,9 @@ void MachineCopyPropagation::forwardUses(MachineInstr &MI) {
if (!Copy)
continue;
- unsigned CopyDstReg = Copy->getOperand(0).getReg();
+ Register CopyDstReg = Copy->getOperand(0).getReg();
const MachineOperand &CopySrc = Copy->getOperand(1);
- unsigned CopySrcReg = CopySrc.getReg();
+ Register CopySrcReg = CopySrc.getReg();
// FIXME: Don't handle partial uses of wider COPYs yet.
if (MOUse.getReg() != CopyDstReg) {
@@ -456,11 +468,11 @@ void MachineCopyPropagation::CopyPropagateBlock(MachineBasicBlock &MBB) {
// Analyze copies (which don't overlap themselves).
if (MI->isCopy() && !TRI->regsOverlap(MI->getOperand(0).getReg(),
MI->getOperand(1).getReg())) {
- unsigned Def = MI->getOperand(0).getReg();
- unsigned Src = MI->getOperand(1).getReg();
+ Register Def = MI->getOperand(0).getReg();
+ Register Src = MI->getOperand(1).getReg();
- assert(!TargetRegisterInfo::isVirtualRegister(Def) &&
- !TargetRegisterInfo::isVirtualRegister(Src) &&
+ assert(!Register::isVirtualRegister(Def) &&
+ !Register::isVirtualRegister(Src) &&
"MachineCopyPropagation should be run after register allocation!");
// The two copies cancel out and the source of the first copy
@@ -488,14 +500,14 @@ void MachineCopyPropagation::CopyPropagateBlock(MachineBasicBlock &MBB) {
// If Src is defined by a previous copy, the previous copy cannot be
// eliminated.
- ReadRegister(Src);
+ ReadRegister(Src, *MI, RegularUse);
for (const MachineOperand &MO : MI->implicit_operands()) {
if (!MO.isReg() || !MO.readsReg())
continue;
- unsigned Reg = MO.getReg();
+ Register Reg = MO.getReg();
if (!Reg)
continue;
- ReadRegister(Reg);
+ ReadRegister(Reg, *MI, RegularUse);
}
LLVM_DEBUG(dbgs() << "MCP: Copy is a deletion candidate: "; MI->dump());
@@ -515,7 +527,7 @@ void MachineCopyPropagation::CopyPropagateBlock(MachineBasicBlock &MBB) {
for (const MachineOperand &MO : MI->implicit_operands()) {
if (!MO.isReg() || !MO.isDef())
continue;
- unsigned Reg = MO.getReg();
+ Register Reg = MO.getReg();
if (!Reg)
continue;
Tracker.clobberRegister(Reg, *TRI);
@@ -529,12 +541,12 @@ void MachineCopyPropagation::CopyPropagateBlock(MachineBasicBlock &MBB) {
// Clobber any earlyclobber regs first.
for (const MachineOperand &MO : MI->operands())
if (MO.isReg() && MO.isEarlyClobber()) {
- unsigned Reg = MO.getReg();
+ Register Reg = MO.getReg();
// If we have a tied earlyclobber, that means it is also read by this
// instruction, so we need to make sure we don't remove it as dead
// later.
if (MO.isTied())
- ReadRegister(Reg);
+ ReadRegister(Reg, *MI, RegularUse);
Tracker.clobberRegister(Reg, *TRI);
}
@@ -548,18 +560,18 @@ void MachineCopyPropagation::CopyPropagateBlock(MachineBasicBlock &MBB) {
RegMask = &MO;
if (!MO.isReg())
continue;
- unsigned Reg = MO.getReg();
+ Register Reg = MO.getReg();
if (!Reg)
continue;
- assert(!TargetRegisterInfo::isVirtualRegister(Reg) &&
+ assert(!Register::isVirtualRegister(Reg) &&
"MachineCopyPropagation should be run after register allocation!");
if (MO.isDef() && !MO.isEarlyClobber()) {
Defs.push_back(Reg);
continue;
- } else if (!MO.isDebug() && MO.readsReg())
- ReadRegister(Reg);
+ } else if (MO.readsReg())
+ ReadRegister(Reg, *MI, MO.isDebug() ? DebugUse : RegularUse);
}
// The instruction has a register mask operand which means that it clobbers
@@ -571,7 +583,7 @@ void MachineCopyPropagation::CopyPropagateBlock(MachineBasicBlock &MBB) {
MaybeDeadCopies.begin();
DI != MaybeDeadCopies.end();) {
MachineInstr *MaybeDead = *DI;
- unsigned Reg = MaybeDead->getOperand(0).getReg();
+ Register Reg = MaybeDead->getOperand(0).getReg();
assert(!MRI->isReserved(Reg));
if (!RegMask->clobbersPhysReg(Reg)) {
@@ -609,9 +621,10 @@ void MachineCopyPropagation::CopyPropagateBlock(MachineBasicBlock &MBB) {
MaybeDead->dump());
assert(!MRI->isReserved(MaybeDead->getOperand(0).getReg()));
- // Update matching debug values.
+ // Update matching debug values, if any.
assert(MaybeDead->isCopy());
- MaybeDead->changeDebugValuesDefReg(MaybeDead->getOperand(1).getReg());
+ unsigned SrcReg = MaybeDead->getOperand(1).getReg();
+ MRI->updateDbgUsersToReg(SrcReg, CopyDbgUsers[MaybeDead]);
MaybeDead->eraseFromParent();
Changed = true;
@@ -620,6 +633,7 @@ void MachineCopyPropagation::CopyPropagateBlock(MachineBasicBlock &MBB) {
}
MaybeDeadCopies.clear();
+ CopyDbgUsers.clear();
Tracker.clear();
}
generated by cgit v1.2.3 (git 2.25.1) at 2025-07-06 14:42:37 +0000