diff --git a/lib/CodeGen/UnreachableBlockElim.cpp b/lib/CodeGen/UnreachableBlockElim.cpp
index 152f2f84e8d..7bf95bf96e5 100644
--- 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 {
@@ -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
@@ -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
diff --git a/lib/Target/X86/X86FloatingPoint.cpp b/lib/Target/X86/X86FloatingPoint.cpp
index 84ed6bae2c6..7dadd44b1ce 100644
--- a/lib/Target/X86/X86FloatingPoint.cpp
+++ b/lib/Target/X86/X86FloatingPoint.cpp
@@ -40,11 +40,11 @@
 #include "llvm/Support/Debug.h"
 #include "llvm/Support/Compiler.h"
 #include "llvm/ADT/DepthFirstIterator.h"
+#include "llvm/ADT/SmallPtrSet.h"
 #include "llvm/ADT/SmallVector.h"
 #include "llvm/ADT/Statistic.h"
 #include "llvm/ADT/STLExtras.h"
 #include <algorithm>
-#include <set>
 using namespace llvm;
 
 STATISTIC(NumFXCH, "Number of fxch instructions inserted");
@@ -192,11 +192,11 @@ bool FPS::runOnMachineFunction(MachineFunction &MF) {
 
   // Process the function in depth first order so that we process at least one
   // of the predecessors for every reachable block in the function.
-  std::set<MachineBasicBlock*> Processed;
+  SmallPtrSet<MachineBasicBlock*, 8> Processed;
   MachineBasicBlock *Entry = MF.begin();
 
   bool Changed = false;
-  for (df_ext_iterator<MachineBasicBlock*, std::set<MachineBasicBlock*> >
+  for (df_ext_iterator<MachineBasicBlock*, SmallPtrSet<MachineBasicBlock*, 8> >
          I = df_ext_begin(Entry, Processed), E = df_ext_end(Entry, Processed);
        I != E; ++I)
     Changed |= processBasicBlock(MF, **I);