Vendor import of llvm release_39 branch r276489:vendor/llvm/llvm-release_39-r276489

https://llvm.org/svn/llvm-project/llvm/branches/release_39@276489

1 files changed, 40 insertions, 25 deletions

diff --git a/lib/CodeGen/LivePhysRegs.cpp b/lib/CodeGen/LivePhysRegs.cpp
index efbbcbe23e15..4e2528f47568 100644
--- a/lib/CodeGen/LivePhysRegs.cpp
+++ b/lib/CodeGen/LivePhysRegs.cpp
@@ -17,6 +17,7 @@
 #include "llvm/CodeGen/MachineFrameInfo.h"
 #include "llvm/CodeGen/MachineFunction.h"
 #include "llvm/CodeGen/MachineInstrBundle.h"
+#include "llvm/CodeGen/MachineRegisterInfo.h"
 #include "llvm/Support/Debug.h"
 #include "llvm/Support/raw_ostream.h"
 using namespace llvm;
@@ -43,7 +44,7 @@ void LivePhysRegs::removeRegsInMask(const MachineOperand &MO,
 /// Remove Defs, add uses. This is the recommended way of calculating liveness.
 void LivePhysRegs::stepBackward(const MachineInstr &MI) {
   // Remove defined registers and regmask kills from the set.
-  for (ConstMIBundleOperands O(&MI); O.isValid(); ++O) {
+  for (ConstMIBundleOperands O(MI); O.isValid(); ++O) {
     if (O->isReg()) {
       if (!O->isDef())
         continue;
@@ -56,8 +57,8 @@ void LivePhysRegs::stepBackward(const MachineInstr &MI) {
   }
 
   // Add uses to the set.
-  for (ConstMIBundleOperands O(&MI); O.isValid(); ++O) {
-    if (!O->isReg() || !O->readsReg() || O->isUndef())
+  for (ConstMIBundleOperands O(MI); O.isValid(); ++O) {
+    if (!O->isReg() || !O->readsReg())
       continue;
     unsigned Reg = O->getReg();
     if (Reg == 0)
@@ -73,7 +74,7 @@ void LivePhysRegs::stepBackward(const MachineInstr &MI) {
 void LivePhysRegs::stepForward(const MachineInstr &MI,
         SmallVectorImpl<std::pair<unsigned, const MachineOperand*>> &Clobbers) {
   // Remove killed registers from the set.
-  for (ConstMIBundleOperands O(&MI); O.isValid(); ++O) {
+  for (ConstMIBundleOperands O(MI); O.isValid(); ++O) {
     if (O->isReg()) {
       unsigned Reg = O->getReg();
       if (Reg == 0)
@@ -120,12 +121,25 @@ void LivePhysRegs::print(raw_ostream &OS) const {
 }
 
 /// Dumps the currently live registers to the debug output.
-void LivePhysRegs::dump() const {
+LLVM_DUMP_METHOD void LivePhysRegs::dump() const {
 #if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
   dbgs() << "  " << *this;
 #endif
 }
 
+bool LivePhysRegs::available(const MachineRegisterInfo &MRI,
+                             unsigned Reg) const {
+  if (LiveRegs.count(Reg))
+    return false;
+  if (MRI.isReserved(Reg))
+    return false;
+  for (MCRegAliasIterator R(Reg, TRI, false); R.isValid(); ++R) {
+    if (LiveRegs.count(*R))
+      return false;
+  }
+  return true;
+}
+
 /// Add live-in registers of basic block \p MBB to \p LiveRegs.
 static void addLiveIns(LivePhysRegs &LiveRegs, const MachineBasicBlock &MBB) {
   for (const auto &LI : MBB.liveins())
@@ -135,40 +149,41 @@ static void addLiveIns(LivePhysRegs &LiveRegs, const MachineBasicBlock &MBB) {
 /// Add pristine registers to the given \p LiveRegs. This function removes
 /// actually saved callee save registers when \p InPrologueEpilogue is false.
 static void addPristines(LivePhysRegs &LiveRegs, const MachineFunction &MF,
+                         const MachineFrameInfo &MFI,
                          const TargetRegisterInfo &TRI) {
-  const MachineFrameInfo &MFI = *MF.getFrameInfo();
-  if (!MFI.isCalleeSavedInfoValid())
-    return;
-
   for (const MCPhysReg *CSR = TRI.getCalleeSavedRegs(&MF); CSR && *CSR; ++CSR)
     LiveRegs.addReg(*CSR);
   for (const CalleeSavedInfo &Info : MFI.getCalleeSavedInfo())
     LiveRegs.removeReg(Info.getReg());
 }
 
-void LivePhysRegs::addLiveOuts(const MachineBasicBlock *MBB,
-                               bool AddPristinesAndCSRs) {
-  if (AddPristinesAndCSRs) {
-    const MachineFunction &MF = *MBB->getParent();
-    addPristines(*this, MF, *TRI);
-    if (!MBB->isReturnBlock()) {
+void LivePhysRegs::addLiveOutsNoPristines(const MachineBasicBlock &MBB) {
+  // To get the live-outs we simply merge the live-ins of all successors.
+  for (const MachineBasicBlock *Succ : MBB.successors())
+    ::addLiveIns(*this, *Succ);
+}
+
+void LivePhysRegs::addLiveOuts(const MachineBasicBlock &MBB) {
+  const MachineFunction &MF = *MBB.getParent();
+  const MachineFrameInfo &MFI = *MF.getFrameInfo();
+  if (MFI.isCalleeSavedInfoValid()) {
+    if (MBB.isReturnBlock()) {
       // The return block has no successors whose live-ins we could merge
       // below. So instead we add the callee saved registers manually.
       for (const MCPhysReg *I = TRI->getCalleeSavedRegs(&MF); *I; ++I)
         addReg(*I);
+    } else {
+      addPristines(*this, MF, MFI, *TRI);
     }
   }
 
-  // To get the live-outs we simply merge the live-ins of all successors.
-  for (const MachineBasicBlock *Succ : MBB->successors())
-    ::addLiveIns(*this, *Succ);
+  addLiveOutsNoPristines(MBB);
 }
 
-void LivePhysRegs::addLiveIns(const MachineBasicBlock *MBB,
-                              bool AddPristines) {
-  if (AddPristines) {
-    const MachineFunction &MF = *MBB->getParent();
-    addPristines(*this, MF, *TRI);
-  }
-  ::addLiveIns(*this, *MBB);
+void LivePhysRegs::addLiveIns(const MachineBasicBlock &MBB) {
+  const MachineFunction &MF = *MBB.getParent();
+  const MachineFrameInfo &MFI = *MF.getFrameInfo();
+  if (MFI.isCalleeSavedInfoValid())
+    addPristines(*this, MF, MFI, *TRI);
+  ::addLiveIns(*this, MBB);
 }