Fold trivial two-operand tokenfactors where the operands are equal

[oota-llvm.git] / lib / CodeGen / UnreachableBlockElim.cpp

diff --git a/lib/CodeGen/UnreachableBlockElim.cpp b/lib/CodeGen/UnreachableBlockElim.cpp
index 57811cab0f67b534599bad61dab6b1f3c353753a..fff9f190a63ac3b8589a67873880fada174e5698 100644 (file)
--- a/lib/CodeGen/UnreachableBlockElim.cpp
+++ b/lib/CodeGen/UnreachableBlockElim.cpp
@@ -32,6 +32,7 @@
 #include "llvm/Support/Compiler.h"
 #include "llvm/Target/TargetInstrInfo.h"
 #include "llvm/ADT/DepthFirstIterator.h"
+#include "llvm/ADT/SmallPtrSet.h"
 using namespace llvm;
 
 namespace {
@@ -39,7 +40,7 @@ namespace {
     virtual bool runOnFunction(Function &F);
   public:
     static char ID; // Pass identification, replacement for typeid
-    UnreachableBlockElim() : FunctionPass((intptr_t)&ID) {}
+    UnreachableBlockElim() : FunctionPass(&ID) {}
   };
 }
 char UnreachableBlockElim::ID = 0;
@@ -51,11 +52,11 @@ FunctionPass *llvm::createUnreachableBlockEliminationPass() {
 }
 
 bool UnreachableBlockElim::runOnFunction(Function &F) {
-  std::set<BasicBlock*> Reachable;
+  SmallPtrSet<BasicBlock*, 8> Reachable;
 
   // Mark all reachable blocks.
-  for (df_ext_iterator<Function*> I = df_ext_begin(&F, Reachable),
-         E = df_ext_end(&F, Reachable); I != E; ++I)
+  for (df_ext_iterator<Function*, SmallPtrSet<BasicBlock*, 8> > I =
+       df_ext_begin(&F, Reachable), E = df_ext_end(&F, Reachable); I != E; ++I)
     /* Mark all reachable blocks */;
 
   // Loop over all dead blocks, remembering them and deleting all instructions
@@ -89,7 +90,7 @@ namespace {
     
   public:
     static char ID; // Pass identification, replacement for typeid
-    UnreachableMachineBlockElim() : MachineFunctionPass((intptr_t)&ID) {}
+    UnreachableMachineBlockElim() : MachineFunctionPass(&ID) {}
   };
 }
 char UnreachableMachineBlockElim::ID = 0;
@@ -101,11 +102,12 @@ Y("unreachable-mbb-elimination",
 const PassInfo *const llvm::UnreachableMachineBlockElimID = &Y;
 
 bool UnreachableMachineBlockElim::runOnMachineFunction(MachineFunction &F) {
-  std::set<MachineBasicBlock*> Reachable;
+  SmallPtrSet<MachineBasicBlock*, 8> Reachable;
 
   // Mark all reachable blocks.
-  for (df_ext_iterator<MachineFunction*> I = df_ext_begin(&F, Reachable),
-         E = df_ext_end(&F, Reachable); I != E; ++I)
+  for (df_ext_iterator<MachineFunction*, SmallPtrSet<MachineBasicBlock*, 8> >
+       I = df_ext_begin(&F, Reachable), E = df_ext_end(&F, Reachable);
+       I != E; ++I)
     /* Mark all reachable blocks */;
 
   // Loop over all dead blocks, remembering them and deleting all instructions
@@ -125,7 +127,7 @@ bool UnreachableMachineBlockElim::runOnMachineFunction(MachineFunction &F) {
         while (start != succ->end() &&
                start->getOpcode() == TargetInstrInfo::PHI) {
           for (unsigned i = start->getNumOperands() - 1; i >= 2; i-=2)
-            if (start->getOperand(i).isMBB() &&
+            if (start->getOperand(i).isMachineBasicBlock() &&
                 start->getOperand(i).getMBB() == BB) {
               start->RemoveOperand(i);
               start->RemoveOperand(i-1);
@@ -152,6 +154,12 @@ bool UnreachableMachineBlockElim::runOnMachineFunction(MachineFunction &F) {
     MachineBasicBlock::iterator phi = BB->begin();
     while (phi != BB->end() &&
            phi->getOpcode() == TargetInstrInfo::PHI) {
+      for (unsigned i = phi->getNumOperands() - 1; i >= 2; i-=2)
+        if (!preds.count(phi->getOperand(i).getMBB())) {
+          phi->RemoveOperand(i);
+          phi->RemoveOperand(i-1);
+        }
+      
       if (phi->getNumOperands() == 3) {
         unsigned Input = phi->getOperand(1).getReg();
         unsigned Output = phi->getOperand(0).getReg();
@@ -162,15 +170,9 @@ bool UnreachableMachineBlockElim::runOnMachineFunction(MachineFunction &F) {
 
         if (Input != Output)
           F.getRegInfo().replaceRegWith(Output, Input);
-        
+
         continue;
       }
-      
-      for (unsigned i = phi->getNumOperands() - 1; i >= 2; i-=2)
-        if (!preds.count(phi->getOperand(i).getMBB())) {
-          phi->RemoveOperand(i);
-          phi->RemoveOperand(i-1);
-        }
   
       ++phi;
     }