LiveRegUnits: Port recent LivePhysRegs bugfixes

Adjust code to look more like the code in LivePhysRegs and port over the
fix for LivePhysRegs from r304001 and adapt to the new CSR management in
MachineRegisterInfo.

llvm-svn: 304622

2 files changed, 32 insertions, 27 deletions

diff --git a/llvm/lib/CodeGen/LivePhysRegs.cpp b/llvm/lib/CodeGen/LivePhysRegs.cpp
index 0dc1079b2ad..cde6ccd29df 100644
--- a/llvm/lib/CodeGen/LivePhysRegs.cpp
+++ b/llvm/lib/CodeGen/LivePhysRegs.cpp
@@ -198,13 +198,12 @@ void LivePhysRegs::addLiveOutsNoPristines(const MachineBasicBlock &MBB) {
 }
 
 void LivePhysRegs::addLiveOuts(const MachineBasicBlock &MBB) {
+  const MachineFunction &MF = *MBB.getParent();
   if (!MBB.succ_empty()) {
-    const MachineFunction &MF = *MBB.getParent();
     addPristines(*this, MF);
     addLiveOutsNoPristines(MBB);
   } else if (MBB.isReturnBlock()) {
     // For the return block: Add all callee saved registers.
-    const MachineFunction &MF = *MBB.getParent();
     const MachineFrameInfo &MFI = MF.getFrameInfo();
     if (MFI.isCalleeSavedInfoValid())
       addCalleeSavedRegs(*this, MF);
diff --git a/llvm/lib/CodeGen/LiveRegUnits.cpp b/llvm/lib/CodeGen/LiveRegUnits.cpp
index dff555f4956..3746b74e052 100644
--- a/llvm/lib/CodeGen/LiveRegUnits.cpp
+++ b/llvm/lib/CodeGen/LiveRegUnits.cpp
@@ -12,11 +12,13 @@
 //===----------------------------------------------------------------------===//
 
 #include "llvm/CodeGen/LiveRegUnits.h"
+
 #include "llvm/CodeGen/MachineBasicBlock.h"
 #include "llvm/CodeGen/MachineFrameInfo.h"
 #include "llvm/CodeGen/MachineFunction.h"
 #include "llvm/CodeGen/MachineInstrBundle.h"
 #include "llvm/CodeGen/MachineOperand.h"
+#include "llvm/CodeGen/MachineRegisterInfo.h"
 #include "llvm/MC/MCRegisterInfo.h"
 #include "llvm/Target/TargetRegisterInfo.h"
 
@@ -81,46 +83,50 @@ void LiveRegUnits::accumulateBackward(const MachineInstr &MI) {
 }
 
 /// Add live-in registers of basic block \p MBB to \p LiveUnits.
-static void addLiveIns(LiveRegUnits &LiveUnits, const MachineBasicBlock &MBB) {
+static void addBlockLiveIns(LiveRegUnits &LiveUnits,
+                            const MachineBasicBlock &MBB) {
   for (const auto &LI : MBB.liveins())
     LiveUnits.addRegMasked(LI.PhysReg, LI.LaneMask);
 }
 
-static void addLiveOuts(LiveRegUnits &LiveUnits, const MachineBasicBlock &MBB) {
-  // To get the live-outs we simply merge the live-ins of all successors.
-  for (const MachineBasicBlock *Succ : MBB.successors())
-    addLiveIns(LiveUnits, *Succ);
+/// Adds all callee saved registers to \p LiveUnits.
+static void addCalleeSavedRegs(LiveRegUnits &LiveUnits,
+                               const MachineFunction &MF) {
+  const MachineRegisterInfo &MRI = MF.getRegInfo();
+  for (const MCPhysReg *CSR = MRI.getCalleeSavedRegs(); CSR && *CSR; ++CSR)
+    LiveUnits.addReg(*CSR);
 }
 
-/// Add pristine registers to the given \p LiveUnits. This function removes
-/// actually saved callee save registers when \p InPrologueEpilogue is false.
-static void removeSavedRegs(LiveRegUnits &LiveUnits, const MachineFunction &MF,
-                            const MachineFrameInfo &MFI,
-                            const TargetRegisterInfo &TRI) {
+/// Adds pristine registers to the given \p LiveUnits. Pristine registers are
+/// callee saved registers that are unused in the function.
+static void addPristines(LiveRegUnits &LiveUnits, const MachineFunction &MF) {
+  const MachineFrameInfo &MFI = MF.getFrameInfo();
+  if (!MFI.isCalleeSavedInfoValid())
+    return;
+  /// Add all callee saved regs, then remove the ones that are saved+restored.
+  addCalleeSavedRegs(LiveUnits, MF);
+  /// Remove the ones that are not saved/restored; they are pristine.
   for (const CalleeSavedInfo &Info : MFI.getCalleeSavedInfo())
     LiveUnits.removeReg(Info.getReg());
 }
 
 void LiveRegUnits::addLiveOuts(const MachineBasicBlock &MBB) {
   const MachineFunction &MF = *MBB.getParent();
-  const MachineFrameInfo &MFI = MF.getFrameInfo();
-  if (MFI.isCalleeSavedInfoValid()) {
-    for (const MCPhysReg *I = TRI->getCalleeSavedRegs(&MF); *I; ++I)
-      addReg(*I);
-    if (!MBB.isReturnBlock())
-      removeSavedRegs(*this, MF, MFI, *TRI);
+  if (!MBB.succ_empty()) {
+    addPristines(*this, MF);
+    // To get the live-outs we simply merge the live-ins of all successors.
+    for (const MachineBasicBlock *Succ : MBB.successors())
+      addBlockLiveIns(*this, *Succ);
+  } else if (MBB.isReturnBlock()) {
+    // For the return block: Add all callee saved registers.
+    const MachineFrameInfo &MFI = MF.getFrameInfo();
+    if (MFI.isCalleeSavedInfoValid())
+      addCalleeSavedRegs(*this, MF);
   }
-  ::addLiveOuts(*this, MBB);
 }
 
 void LiveRegUnits::addLiveIns(const MachineBasicBlock &MBB) {
   const MachineFunction &MF = *MBB.getParent();
-  const MachineFrameInfo &MFI = MF.getFrameInfo();
-  if (MFI.isCalleeSavedInfoValid()) {
-    for (const MCPhysReg *I = TRI->getCalleeSavedRegs(&MF); *I; ++I)
-      addReg(*I);
-    if (&MBB != &MF.front())
-      removeSavedRegs(*this, MF, MFI, *TRI);
-  }
-  ::addLiveIns(*this, MBB);
+  addPristines(*this, MF);
+  addBlockLiveIns(*this, MBB);
 }