Add an analyzePhysReg() function to MachineOperandIteratorBase that analyses an instruction's use of a physical register, analogous to analyzeVirtReg.

Rename RegInfo to VirtRegInfo so as not to be confused with the new PhysRegInfo.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@163694 91177308-0d34-0410-b5e6-96231b3b80d8

3 files changed, 91 insertions, 7 deletions

diff --git a/include/llvm/CodeGen/MachineInstrBundle.h b/include/llvm/CodeGen/MachineInstrBundle.h
index dc5f9a6ec8..854ba06209 100644
--- a/include/llvm/CodeGen/MachineInstrBundle.h
+++ b/include/llvm/CodeGen/MachineInstrBundle.h
@@ -130,9 +130,9 @@ public:
     return OpI - InstrI->operands_begin();
   }
 
-  /// RegInfo - Information about a virtual register used by a set of operands.
+  /// VirtRegInfo - Information about a virtual register used by a set of operands.
   ///
-  struct RegInfo {
+  struct VirtRegInfo {
     /// Reads - One of the operands read the virtual register.  This does not
     /// include <undef> or <internal> use operands, see MO::readsReg().
     bool Reads;
@@ -146,6 +146,32 @@ public:
     bool Tied;
   };
 
+  /// PhysRegInfo - Information about a physical register used by a set of
+  /// operands.
+  struct PhysRegInfo {
+    /// Clobbers - Reg or an overlapping register is defined, or a regmask 
+    /// clobbers Reg.
+    bool Clobbers;
+
+    /// Defines - Reg or a super-register is defined.
+    bool Defines;
+
+    /// DefinesOverlap - Reg or an overlapping register is defined.
+    bool DefinesOverlap;
+
+    /// Reads - Read or a super-register is read.
+    bool Reads;
+
+    /// ReadsOverlap - Reg or an overlapping register is read.
+    bool ReadsOverlap;
+
+    /// DefinesDead - All defs of a Reg or a super-register are dead.
+    bool DefinesDead;
+
+    /// There is a kill of Reg or a super-register.
+    bool Kills;
+  };
+
   /// analyzeVirtReg - Analyze how the current instruction or bundle uses a
   /// virtual register.  This function should not be called after operator++(),
   /// it expects a fresh iterator.
@@ -154,8 +180,16 @@ public:
   /// @param Ops When set, this vector will receive an (MI, OpNum) entry for
   ///            each operand referring to Reg.
   /// @returns A filled-in RegInfo struct.
-  RegInfo analyzeVirtReg(unsigned Reg,
+  VirtRegInfo analyzeVirtReg(unsigned Reg,
                  SmallVectorImpl<std::pair<MachineInstr*, unsigned> > *Ops = 0);
+
+  /// analyzePhysReg - Analyze how the current instruction or bundle uses a
+  /// physical register.  This function should not be called after operator++(),
+  /// it expects a fresh iterator.
+  ///
+  /// @param Reg The physical register to analyze.
+  /// @returns A filled-in PhysRegInfo struct.
+  PhysRegInfo analyzePhysReg(unsigned Reg, const TargetRegisterInfo *TRI);
 };
 
 /// MIOperands - Iterate over operands of a single instruction.
diff --git a/lib/CodeGen/InlineSpiller.cpp b/lib/CodeGen/InlineSpiller.cpp
index 622127cc74..37828a70b5 100644
--- a/lib/CodeGen/InlineSpiller.cpp
+++ b/lib/CodeGen/InlineSpiller.cpp
@@ -863,7 +863,7 @@ bool InlineSpiller::reMaterializeFor(LiveInterval &VirtReg,
   // If the instruction also writes VirtReg.reg, it had better not require the
   // same register for uses and defs.
   SmallVector<std::pair<MachineInstr*, unsigned>, 8> Ops;
-  MIBundleOperands::RegInfo RI =
+  MIBundleOperands::VirtRegInfo RI =
     MIBundleOperands(MI).analyzeVirtReg(VirtReg.reg, &Ops);
   if (RI.Tied) {
     markValueUsed(&VirtReg, ParentVNI);
@@ -1142,7 +1142,7 @@ void InlineSpiller::spillAroundUses(unsigned Reg) {
 
     // Analyze instruction.
     SmallVector<std::pair<MachineInstr*, unsigned>, 8> Ops;
-    MIBundleOperands::RegInfo RI =
+    MIBundleOperands::VirtRegInfo RI =
       MIBundleOperands(MI).analyzeVirtReg(Reg, &Ops);
 
     // Find the slot index where this instruction reads and writes OldLI.
diff --git a/lib/CodeGen/MachineInstrBundle.cpp b/lib/CodeGen/MachineInstrBundle.cpp
index b7de7bfb49..ff7ad039b3 100644
--- a/lib/CodeGen/MachineInstrBundle.cpp
+++ b/lib/CodeGen/MachineInstrBundle.cpp
@@ -248,10 +248,10 @@ bool llvm::finalizeBundles(MachineFunction &MF) {
 // MachineOperand iterator
 //===----------------------------------------------------------------------===//
 
-MachineOperandIteratorBase::RegInfo
+MachineOperandIteratorBase::VirtRegInfo
 MachineOperandIteratorBase::analyzeVirtReg(unsigned Reg,
                     SmallVectorImpl<std::pair<MachineInstr*, unsigned> > *Ops) {
-  RegInfo RI = { false, false, false };
+  VirtRegInfo RI = { false, false, false };
   for(; isValid(); ++*this) {
     MachineOperand &MO = deref();
     if (!MO.isReg() || MO.getReg() != Reg)
@@ -276,3 +276,53 @@ MachineOperandIteratorBase::analyzeVirtReg(unsigned Reg,
   }
   return RI;
 }
+
+MachineOperandIteratorBase::PhysRegInfo
+MachineOperandIteratorBase::analyzePhysReg(unsigned Reg,
+                                           const TargetRegisterInfo *TRI) {
+  bool AllDefsDead = true;
+  PhysRegInfo PRI = {false, false, false, false, false, false, false};
+
+  assert(TargetRegisterInfo::isPhysicalRegister(Reg) &&
+         "analyzePhysReg not given a physical register!");
+  for (; isValid(); ++*this) {
+    MachineOperand &MO = deref();
+
+    if (MO.isRegMask() && MO.clobbersPhysReg(Reg))
+      PRI.Clobbers = true;    // Regmask clobbers Reg.
+
+    if (!MO.isReg())
+      continue;
+
+    unsigned MOReg = MO.getReg();
+    if (!MOReg || !TargetRegisterInfo::isPhysicalRegister(MOReg))
+      continue;
+
+    bool IsRegOrSuperReg = MOReg == Reg || TRI->isSubRegister(MOReg, Reg);
+    bool IsRegOrOverlapping = MOReg == Reg || TRI->regsOverlap(MOReg, Reg);
+
+    if (IsRegOrSuperReg && MO.readsReg()) {
+      // Reg or a super-reg is read, and perhaps killed also.
+      PRI.Reads = true;
+      PRI.Kills = MO.isKill();
+    } if (IsRegOrOverlapping && MO.readsReg()) {
+      PRI.ReadsOverlap = true;// Reg or an overlapping register is read.
+    }
+    
+    if (!MO.isDef())
+      continue;
+
+    if (IsRegOrSuperReg) {
+      PRI.Defines = true;     // Reg or a super-register is defined.
+      if (!MO.isDead())
+        AllDefsDead = false;
+    }
+    if (IsRegOrOverlapping)
+      PRI.Clobbers = true;    // Reg or an overlapping reg is defined.
+  }
+
+  if (AllDefsDead && PRI.Defines)
+    PRI.DefinesDead = true;   // Reg or super-register was defined and was dead.
+
+  return PRI;
+}