diff --git a/lib/Target/CBackend/CBackend.cpp b/lib/Target/CBackend/CBackend.cpp
index c26cfee..5b786d4 100644
--- a/lib/Target/CBackend/CBackend.cpp
+++ b/lib/Target/CBackend/CBackend.cpp
@@ -1224,8 +1224,8 @@
                                           unsigned Indent) {
   for (succ_iterator SI = succ_begin(CurBlock), E = succ_end(CurBlock);
        SI != E; ++SI)
-    for (BasicBlock::iterator I = SI->begin();
-         PHINode *PN = dyn_cast<PHINode>(I); ++I) {
+    for (BasicBlock::iterator I = SI->begin(); isa<PHINode>(I); ++I) {
+      PHINode *PN = cast<PHINode>(I);
       //  now we have to do the printing
       Out << std::string(Indent, ' ');
       Out << "  " << Mang->getValueName(I) << "__PHI_TEMPORARY = ";
diff --git a/lib/Target/CBackend/Writer.cpp b/lib/Target/CBackend/Writer.cpp
index c26cfee..5b786d4 100644
--- a/lib/Target/CBackend/Writer.cpp
+++ b/lib/Target/CBackend/Writer.cpp
@@ -1224,8 +1224,8 @@
                                           unsigned Indent) {
   for (succ_iterator SI = succ_begin(CurBlock), E = succ_end(CurBlock);
        SI != E; ++SI)
-    for (BasicBlock::iterator I = SI->begin();
-         PHINode *PN = dyn_cast<PHINode>(I); ++I) {
+    for (BasicBlock::iterator I = SI->begin(); isa<PHINode>(I); ++I) {
+      PHINode *PN = cast<PHINode>(I);
       //  now we have to do the printing
       Out << std::string(Indent, ' ');
       Out << "  " << Mang->getValueName(I) << "__PHI_TEMPORARY = ";
diff --git a/lib/Transforms/Utils/LoopSimplify.cpp b/lib/Transforms/Utils/LoopSimplify.cpp
index c576149..aa3a865 100644
--- a/lib/Transforms/Utils/LoopSimplify.cpp
+++ b/lib/Transforms/Utils/LoopSimplify.cpp
@@ -213,8 +213,8 @@
   if (!Preds.empty()) {  // Is the loop not obviously dead?
     // Check to see if the values being merged into the new block need PHI
     // nodes.  If so, insert them.
-    for (BasicBlock::iterator I = BB->begin();
-         PHINode *PN = dyn_cast<PHINode>(I); ) {
+    for (BasicBlock::iterator I = BB->begin(); isa<PHINode>(I); ) {
+      PHINode *PN = cast<PHINode>(I);
       ++I;
 
       // Check to see if all of the values coming in are the same.  If so, we
@@ -266,10 +266,11 @@
     }
     
   } else {                       // Otherwise the loop is dead...
-    for (BasicBlock::iterator I = BB->begin();
-         PHINode *PN = dyn_cast<PHINode>(I); ++I)
+    for (BasicBlock::iterator I = BB->begin(); isa<PHINode>(I); ++I) {
+      PHINode *PN = cast<PHINode>(I);
       // Insert dummy values as the incoming value...
       PN->addIncoming(Constant::getNullValue(PN->getType()), NewBB);
+    }
   }  
   return NewBB;
 }
@@ -426,8 +427,8 @@
 /// FindPHIToPartitionLoops - The first part of loop-nestification is to find a
 /// PHI node that tells us how to partition the loops.
 static PHINode *FindPHIToPartitionLoops(Loop *L) {
-  for (BasicBlock::iterator I = L->getHeader()->begin();
-       PHINode *PN = dyn_cast<PHINode>(I); ) {
+  for (BasicBlock::iterator I = L->getHeader()->begin(); isa<PHINode>(I); ) {
+    PHINode *PN = cast<PHINode>(I);
     ++I;
     if (Value *V = hasConstantValue(PN)) {
       // This is a degenerate PHI already, don't modify it!
@@ -565,8 +566,8 @@
   
   // Now that the block has been inserted into the function, create PHI nodes in
   // the backedge block which correspond to any PHI nodes in the header block.
-  for (BasicBlock::iterator I = Header->begin();
-       PHINode *PN = dyn_cast<PHINode>(I); ++I) {
+  for (BasicBlock::iterator I = Header->begin(); isa<PHINode>(I); ++I) {
+    PHINode *PN = cast<PHINode>(I);
     PHINode *NewPN = new PHINode(PN->getType(), PN->getName()+".be",
                                  BETerminator);
     NewPN->op_reserve(2*BackedgeBlocks.size());