Transfer regmasks to MRI.

MRI keeps track of which physregs have been used. Make sure it gets
updated with all the regmask-clobbered registers.

Delete the closePhysRegsUsed() function which isn't necessary.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@150830 91177308-0d34-0410-b5e6-96231b3b80d8

4 files changed, 29 insertions, 21 deletions

diff --git a/include/llvm/CodeGen/MachineRegisterInfo.h b/include/llvm/CodeGen/MachineRegisterInfo.h
index b121dc5df7..ea108f443c 100644
--- a/include/llvm/CodeGen/MachineRegisterInfo.h
+++ b/include/llvm/CodeGen/MachineRegisterInfo.h
@@ -56,8 +56,13 @@ class MachineRegisterInfo {
   /// register allocation (though most don't modify this).  This is used
   /// so that the code generator knows which callee save registers to save and
   /// for other target specific uses.
+  /// This vector only has bits set for registers explicitly used, not their
+  /// aliases.
   BitVector UsedPhysRegs;
 
+  /// UsedPhysRegMask - Additional used physregs, but including aliases.
+  BitVector UsedPhysRegMask;
+
   /// ReservedRegs - This is a bit vector of reserved registers.  The target
   /// may change its mind about which registers should be reserved.  This
   /// vector is the frozen set of reserved registers when register allocation
@@ -296,32 +301,41 @@ public:
   
   /// isPhysRegUsed - Return true if the specified register is used in this
   /// function.  This only works after register allocation.
-  bool isPhysRegUsed(unsigned Reg) const { return UsedPhysRegs[Reg]; }
+  bool isPhysRegUsed(unsigned Reg) const {
+    return UsedPhysRegs.test(Reg) || UsedPhysRegMask.test(Reg);
+  }
 
   /// isPhysRegOrOverlapUsed - Return true if Reg or any overlapping register
   /// is used in this function.
   bool isPhysRegOrOverlapUsed(unsigned Reg) const {
+    if (UsedPhysRegMask.test(Reg))
+      return true;
     for (const unsigned *AI = TRI->getOverlaps(Reg); *AI; ++AI)
-      if (isPhysRegUsed(*AI))
+      if (UsedPhysRegs.test(*AI))
         return true;
     return false;
   }
 
   /// setPhysRegUsed - Mark the specified register used in this function.
   /// This should only be called during and after register allocation.
-  void setPhysRegUsed(unsigned Reg) { UsedPhysRegs[Reg] = true; }
+  void setPhysRegUsed(unsigned Reg) { UsedPhysRegs.set(Reg); }
 
   /// addPhysRegsUsed - Mark the specified registers used in this function.
   /// This should only be called during and after register allocation.
   void addPhysRegsUsed(const BitVector &Regs) { UsedPhysRegs |= Regs; }
 
+  /// addPhysRegsUsedFromRegMask - Mark any registers not in RegMask as used.
+  /// This corresponds to the bit mask attached to register mask operands.
+  void addPhysRegsUsedFromRegMask(const uint32_t *RegMask) {
+    UsedPhysRegMask.setBitsNotInMask(RegMask);
+  }
+
   /// setPhysRegUnused - Mark the specified register unused in this function.
   /// This should only be called during and after register allocation.
-  void setPhysRegUnused(unsigned Reg) { UsedPhysRegs[Reg] = false; }
-
-  /// closePhysRegsUsed - Expand UsedPhysRegs to its transitive closure over
-  /// subregisters. That means that if R is used, so are all subregisters.
-  void closePhysRegsUsed(const TargetRegisterInfo&);
+  void setPhysRegUnused(unsigned Reg) {
+    UsedPhysRegs.reset(Reg);
+    UsedPhysRegMask.reset(Reg);
+  }
 
 
   //===--------------------------------------------------------------------===//
diff --git a/lib/CodeGen/MachineRegisterInfo.cpp b/lib/CodeGen/MachineRegisterInfo.cpp
index 6ec55247bf..08bf1ae910 100644
--- a/lib/CodeGen/MachineRegisterInfo.cpp
+++ b/lib/CodeGen/MachineRegisterInfo.cpp
@@ -22,7 +22,8 @@ MachineRegisterInfo::MachineRegisterInfo(const TargetRegisterInfo &TRI)
   VRegInfo.reserve(256);
   RegAllocHints.reserve(256);
   UsedPhysRegs.resize(TRI.getNumRegs());
-  
+  UsedPhysRegMask.resize(TRI.getNumRegs());
+
   // Create the physreg use/def lists.
   PhysRegUseDefLists = new MachineOperand*[TRI.getNumRegs()];
   memset(PhysRegUseDefLists, 0, sizeof(MachineOperand*)*TRI.getNumRegs());
@@ -244,15 +245,6 @@ MachineRegisterInfo::EmitLiveInCopies(MachineBasicBlock *EntryMBB,
     }
 }
 
-void MachineRegisterInfo::closePhysRegsUsed(const TargetRegisterInfo &TRI) {
-  for (int i = UsedPhysRegs.find_first(); i >= 0;
-       i = UsedPhysRegs.find_next(i))
-         for (const unsigned *SS = TRI.getSubRegisters(i);
-              unsigned SubReg = *SS; ++SS)
-           if (SubReg > unsigned(i))
-             UsedPhysRegs.set(SubReg);
-}
-
 #ifndef NDEBUG
 void MachineRegisterInfo::dumpUses(unsigned Reg) const {
   for (use_iterator I = use_begin(Reg), E = use_end(); I != E; ++I)
diff --git a/lib/CodeGen/RegAllocFast.cpp b/lib/CodeGen/RegAllocFast.cpp
index 4724ca2f92..6d7b5f4b65 100644
--- a/lib/CodeGen/RegAllocFast.cpp
+++ b/lib/CodeGen/RegAllocFast.cpp
@@ -1097,9 +1097,6 @@ bool RAFast::runOnMachineFunction(MachineFunction &Fn) {
     AllocateBasicBlock();
   }
 
-  // Make sure the set of used physregs is closed under subreg operations.
-  MRI->closePhysRegsUsed(*TRI);
-
   // Add the clobber lists for all the instructions we skipped earlier.
   for (SmallPtrSet<const MCInstrDesc*, 4>::const_iterator
        I = SkippedInstrs.begin(), E = SkippedInstrs.end(); I != E; ++I)
diff --git a/lib/CodeGen/VirtRegMap.cpp b/lib/CodeGen/VirtRegMap.cpp
index 5daa6a7dc1..3bab93bdc0 100644
--- a/lib/CodeGen/VirtRegMap.cpp
+++ b/lib/CodeGen/VirtRegMap.cpp
@@ -127,6 +127,11 @@ void VirtRegMap::rewrite(SlotIndexes *Indexes) {
       for (MachineInstr::mop_iterator MOI = MI->operands_begin(),
            MOE = MI->operands_end(); MOI != MOE; ++MOI) {
         MachineOperand &MO = *MOI;
+
+        // Make sure MRI knows about registers clobbered by regmasks.
+        if (MO.isRegMask())
+          MRI->addPhysRegsUsedFromRegMask(MO.getRegMask());
+
         if (!MO.isReg() || !TargetRegisterInfo::isVirtualRegister(MO.getReg()))
           continue;
         unsigned VirtReg = MO.getReg();