Dead code elimination

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@96837 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/CodeGen/PHIElimination.cpp b/lib/CodeGen/PHIElimination.cpp
index bc49d0de2238815deec6b080cbf339aad6cfc81a..9e4bc0c273f7d45b04e298f68e204f1ff2622a27 100644 (file)
--- a/lib/CodeGen/PHIElimination.cpp
+++ b/lib/CodeGen/PHIElimination.cpp
@@ -55,7 +55,6 @@ void llvm::PHIElimination::getAnalysisUsage(AnalysisUsage &AU) const {
 bool llvm::PHIElimination::runOnMachineFunction(MachineFunction &Fn) {
   MRI = &Fn.getRegInfo();
 
-  PHIDefs.clear();
   bool Changed = false;
 
   // Split critical edges to help the coalescer
@@ -214,10 +213,6 @@ void llvm::PHIElimination::LowerAtomicPHINode(
     TII->copyRegToReg(MBB, AfterPHIsIt, DestReg, IncomingReg, RC, RC);
   }
 
-  // Record PHI def.
-  assert(!hasPHIDef(DestReg) && "Vreg has multiple phi-defs?");
-  PHIDefs[DestReg] = &MBB;
-
   // Update live variable information if there is any.
   LiveVariables *LV = getAnalysisIfAvailable<LiveVariables>();
   if (LV) {

diff --git a/lib/CodeGen/PHIElimination.h b/lib/CodeGen/PHIElimination.h
index 110721d01d67472101be34a7941f8272c8e798d5..ff4aa20918545955104abeac6a98cbef4437c447 100644 (file)
--- a/lib/CodeGen/PHIElimination.h
+++ b/lib/CodeGen/PHIElimination.h
@@ -22,10 +22,8 @@ namespace llvm {
   /// Lower PHI instructions to copies.  
   class PHIElimination : public MachineFunctionPass {
     MachineRegisterInfo  *MRI; // Machine register information
-    typedef DenseMap<unsigned, MachineBasicBlock*> PHIDefMap;
 
   public:
-
     static char ID; // Pass identification, replacement for typeid
     PHIElimination() : MachineFunctionPass(&ID) {}
 
@@ -33,12 +31,6 @@ namespace llvm {
     
     virtual void getAnalysisUsage(AnalysisUsage &AU) const;
 
-    /// Return true if the given vreg was defined by a PHI intsr prior to
-    /// lowering.
-    bool hasPHIDef(unsigned vreg) const {
-      return PHIDefs.count(vreg);
-    }
-
   private:
     /// EliminatePHINodes - Eliminate phi nodes by inserting copy instructions
     /// in predecessor basic blocks.
@@ -106,7 +98,6 @@ namespace llvm {
     typedef DenseMap<BBVRegPair, unsigned> VRegPHIUse;
 
     VRegPHIUse VRegPHIUseCount;
-    PHIDefMap PHIDefs;
 
     // Defs of PHI sources which are implicit_def.
     SmallPtrSet<MachineInstr*, 4> ImpDefs;