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 bc49d0d..9e4bc0c 100644
--- a/lib/CodeGen/PHIElimination.cpp
+++ b/lib/CodeGen/PHIElimination.cpp
@@ -55,7 +55,6 @@
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 @@
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 110721d..ff4aa20 100644
--- a/lib/CodeGen/PHIElimination.h
+++ b/lib/CodeGen/PHIElimination.h
@@ -22,10 +22,8 @@
/// 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 @@
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 @@
typedef DenseMap<BBVRegPair, unsigned> VRegPHIUse;
VRegPHIUse VRegPHIUseCount;
- PHIDefMap PHIDefs;
// Defs of PHI sources which are implicit_def.
SmallPtrSet<MachineInstr*, 4> ImpDefs;