diff --git a/lib/Analysis/ConstantFolding.cpp b/lib/Analysis/ConstantFolding.cpp
index 7ac8b97..173326e 100644
--- a/lib/Analysis/ConstantFolding.cpp
+++ b/lib/Analysis/ConstantFolding.cpp
@@ -617,64 +617,31 @@
   }
 
   if (!F->hasName()) return false;
-  const char *Str = F->getNameStart();
-  unsigned Len = F->getNameLen();
+  StringRef Name = F->getName();
   
   // In these cases, the check of the length is required.  We don't want to
   // return true for a name like "cos\0blah" which strcmp would return equal to
   // "cos", but has length 8.
-  switch (Str[0]) {
+  switch (Name[0]) {
   default: return false;
   case 'a':
-    if (Len == 4)
-      return !strcmp(Str, "acos") || !strcmp(Str, "asin") ||
-             !strcmp(Str, "atan");
-    else if (Len == 5)
-      return !strcmp(Str, "atan2");
-    return false;
+    return Name == "acos" || Name == "asin" || 
+      Name == "atan" || Name == "atan2";
   case 'c':
-    if (Len == 3)
-      return !strcmp(Str, "cos");
-    else if (Len == 4)
-      return !strcmp(Str, "ceil") || !strcmp(Str, "cosf") ||
-             !strcmp(Str, "cosh");
-    return false;
+    return Name == "cos" || Name == "ceil" || Name == "cosf" || Name == "cosh";
   case 'e':
-    if (Len == 3)
-      return !strcmp(Str, "exp");
-    return false;
+    return Name == "exp";
   case 'f':
-    if (Len == 4)
-      return !strcmp(Str, "fabs") || !strcmp(Str, "fmod");
-    else if (Len == 5)
-      return !strcmp(Str, "floor");
-    return false;
-    break;
+    return Name == "fabs" || Name == "fmod" || Name == "floor";
   case 'l':
-    if (Len == 3 && !strcmp(Str, "log"))
-      return true;
-    if (Len == 5 && !strcmp(Str, "log10"))
-      return true;
-    return false;
+    return Name == "log" || Name == "log10";
   case 'p':
-    if (Len == 3 && !strcmp(Str, "pow"))
-      return true;
-    return false;
+    return Name == "pow";
   case 's':
-    if (Len == 3)
-      return !strcmp(Str, "sin");
-    if (Len == 4)
-      return !strcmp(Str, "sinh") || !strcmp(Str, "sqrt") ||
-             !strcmp(Str, "sinf");
-    if (Len == 5)
-      return !strcmp(Str, "sqrtf");
-    return false;
+    return Name == "sin" || Name == "sinh" || Name == "sqrt" ||
+      Name == "sinf" || Name == "sqrtf";
   case 't':
-    if (Len == 3 && !strcmp(Str, "tan"))
-      return true;
-    else if (Len == 4 && !strcmp(Str, "tanh"))
-      return true;
-    return false;
+    return Name == "tan" || Name == "tanh";
   }
 }
 
@@ -722,8 +689,7 @@
                        Constant* const* Operands, unsigned NumOperands) {
   if (!F->hasName()) return 0;
   LLVMContext &Context = F->getContext();
-  const char *Str = F->getNameStart();
-  unsigned Len = F->getNameLen();
+  StringRef Name = F->getName();
   
   const Type *Ty = F->getReturnType();
   if (NumOperands == 1) {
@@ -736,42 +702,42 @@
       /// f(arg).  Long double not supported yet.
       double V = Ty==Type::FloatTy ? (double)Op->getValueAPF().convertToFloat():
                                      Op->getValueAPF().convertToDouble();
-      switch (Str[0]) {
+      switch (Name[0]) {
       case 'a':
-        if (Len == 4 && !strcmp(Str, "acos"))
+        if (Name == "acos")
           return ConstantFoldFP(acos, V, Ty, Context);
-        else if (Len == 4 && !strcmp(Str, "asin"))
+        else if (Name == "asin")
           return ConstantFoldFP(asin, V, Ty, Context);
-        else if (Len == 4 && !strcmp(Str, "atan"))
+        else if (Name == "atan")
           return ConstantFoldFP(atan, V, Ty, Context);
         break;
       case 'c':
-        if (Len == 4 && !strcmp(Str, "ceil"))
+        if (Name == "ceil")
           return ConstantFoldFP(ceil, V, Ty, Context);
-        else if (Len == 3 && !strcmp(Str, "cos"))
+        else if (Name == "cos")
           return ConstantFoldFP(cos, V, Ty, Context);
-        else if (Len == 4 && !strcmp(Str, "cosh"))
+        else if (Name == "cosh")
           return ConstantFoldFP(cosh, V, Ty, Context);
-        else if (Len == 4 && !strcmp(Str, "cosf"))
+        else if (Name == "cosf")
           return ConstantFoldFP(cos, V, Ty, Context);
         break;
       case 'e':
-        if (Len == 3 && !strcmp(Str, "exp"))
+        if (Name == "exp")
           return ConstantFoldFP(exp, V, Ty, Context);
         break;
       case 'f':
-        if (Len == 4 && !strcmp(Str, "fabs"))
+        if (Name == "fabs")
           return ConstantFoldFP(fabs, V, Ty, Context);
-        else if (Len == 5 && !strcmp(Str, "floor"))
+        else if (Name == "floor")
           return ConstantFoldFP(floor, V, Ty, Context);
         break;
       case 'l':
-        if (Len == 3 && !strcmp(Str, "log") && V > 0)
+        if (Name == "log" && V > 0)
           return ConstantFoldFP(log, V, Ty, Context);
-        else if (Len == 5 && !strcmp(Str, "log10") && V > 0)
+        else if (Name == "log10" && V > 0)
           return ConstantFoldFP(log10, V, Ty, Context);
-        else if (!strcmp(Str, "llvm.sqrt.f32") ||
-                 !strcmp(Str, "llvm.sqrt.f64")) {
+        else if (Name == "llvm.sqrt.f32" ||
+                 Name == "llvm.sqrt.f64") {
           if (V >= -0.0)
             return ConstantFoldFP(sqrt, V, Ty, Context);
           else // Undefined
@@ -779,34 +745,34 @@
         }
         break;
       case 's':
-        if (Len == 3 && !strcmp(Str, "sin"))
+        if (Name == "sin")
           return ConstantFoldFP(sin, V, Ty, Context);
-        else if (Len == 4 && !strcmp(Str, "sinh"))
+        else if (Name == "sinh")
           return ConstantFoldFP(sinh, V, Ty, Context);
-        else if (Len == 4 && !strcmp(Str, "sqrt") && V >= 0)
+        else if (Name == "sqrt" && V >= 0)
           return ConstantFoldFP(sqrt, V, Ty, Context);
-        else if (Len == 5 && !strcmp(Str, "sqrtf") && V >= 0)
+        else if (Name == "sqrtf" && V >= 0)
           return ConstantFoldFP(sqrt, V, Ty, Context);
-        else if (Len == 4 && !strcmp(Str, "sinf"))
+        else if (Name == "sinf")
           return ConstantFoldFP(sin, V, Ty, Context);
         break;
       case 't':
-        if (Len == 3 && !strcmp(Str, "tan"))
+        if (Name == "tan")
           return ConstantFoldFP(tan, V, Ty, Context);
-        else if (Len == 4 && !strcmp(Str, "tanh"))
+        else if (Name == "tanh")
           return ConstantFoldFP(tanh, V, Ty, Context);
         break;
       default:
         break;
       }
     } else if (ConstantInt *Op = dyn_cast<ConstantInt>(Operands[0])) {
-      if (Len > 11 && !memcmp(Str, "llvm.bswap", 10))
+      if (Name.startswith("llvm.bswap"))
         return ConstantInt::get(Context, Op->getValue().byteSwap());
-      else if (Len > 11 && !memcmp(Str, "llvm.ctpop", 10))
+      else if (Name.startswith("llvm.ctpop"))
         return ConstantInt::get(Ty, Op->getValue().countPopulation());
-      else if (Len > 10 && !memcmp(Str, "llvm.cttz", 9))
+      else if (Name.startswith("llvm.cttz"))
         return ConstantInt::get(Ty, Op->getValue().countTrailingZeros());
-      else if (Len > 10 && !memcmp(Str, "llvm.ctlz", 9))
+      else if (Name.startswith("llvm.ctlz"))
         return ConstantInt::get(Ty, Op->getValue().countLeadingZeros());
     }
   } else if (NumOperands == 2) {
@@ -821,18 +787,18 @@
                       (double)Op2->getValueAPF().convertToFloat():
                       Op2->getValueAPF().convertToDouble();
 
-        if (Len == 3 && !strcmp(Str, "pow")) {
+        if (Name == "pow") {
           return ConstantFoldBinaryFP(pow, Op1V, Op2V, Ty, Context);
-        } else if (Len == 4 && !strcmp(Str, "fmod")) {
+        } else if (Name == "fmod") {
           return ConstantFoldBinaryFP(fmod, Op1V, Op2V, Ty, Context);
-        } else if (Len == 5 && !strcmp(Str, "atan2")) {
+        } else if (Name == "atan2") {
           return ConstantFoldBinaryFP(atan2, Op1V, Op2V, Ty, Context);
         }
       } else if (ConstantInt *Op2C = dyn_cast<ConstantInt>(Operands[1])) {
-        if (!strcmp(Str, "llvm.powi.f32")) {
+        if (Name == "llvm.powi.f32") {
           return Context.getConstantFP(APFloat((float)std::pow((float)Op1V,
                                                  (int)Op2C->getZExtValue())));
-        } else if (!strcmp(Str, "llvm.powi.f64")) {
+        } else if (Name == "llvm.powi.f64") {
           return Context.getConstantFP(APFloat((double)std::pow((double)Op1V,
                                                  (int)Op2C->getZExtValue())));
         }
diff --git a/lib/Analysis/LibCallSemantics.cpp b/lib/Analysis/LibCallSemantics.cpp
index 01fe730..e0060c3 100644
--- a/lib/Analysis/LibCallSemantics.cpp
+++ b/lib/Analysis/LibCallSemantics.cpp
@@ -57,9 +57,6 @@
   }
   
   // Look up this function in the string map.
-  const char *ValueName = F->getNameStart();
-  StringMap<const LibCallFunctionInfo*>::iterator I =
-    Map->find(StringRef(ValueName, F->getNameLen()));
-  return I != Map->end() ? I->second : 0;
+  return Map->lookup(F->getName());
 }
 
diff --git a/lib/Analysis/ValueTracking.cpp b/lib/Analysis/ValueTracking.cpp
index b392b7e..fcb8188 100644
--- a/lib/Analysis/ValueTracking.cpp
+++ b/lib/Analysis/ValueTracking.cpp
@@ -800,15 +800,11 @@
   if (const CallInst *CI = dyn_cast<CallInst>(I))
     if (const Function *F = CI->getCalledFunction()) {
       if (F->isDeclaration()) {
-        switch (F->getNameLen()) {
-        case 3:  // abs(x) != -0.0
-          if (!strcmp(F->getNameStart(), "abs")) return true;
-          break;
-        case 4:  // abs[lf](x) != -0.0
-          if (!strcmp(F->getNameStart(), "absf")) return true;
-          if (!strcmp(F->getNameStart(), "absl")) return true;
-          break;
-        }
+        // abs(x) != -0.0
+        if (F->getName() == "abs") return true;
+        // abs[lf](x) != -0.0
+        if (F->getName() == "absf") return true;
+        if (F->getName() == "absl") return true;
       }
     }
   
diff --git a/lib/CodeGen/SelectionDAG/SelectionDAGBuild.cpp b/lib/CodeGen/SelectionDAG/SelectionDAGBuild.cpp
index 1135376..8685c85 100644
--- a/lib/CodeGen/SelectionDAG/SelectionDAGBuild.cpp
+++ b/lib/CodeGen/SelectionDAG/SelectionDAGBuild.cpp
@@ -4439,12 +4439,9 @@
 
     // Check for well-known libc/libm calls.  If the function is internal, it
     // can't be a library call.
-    unsigned NameLen = F->getNameLen();
-    if (!F->hasLocalLinkage() && NameLen) {
-      const char *NameStr = F->getNameStart();
-      if (NameStr[0] == 'c' &&
-          ((NameLen == 8 && !strcmp(NameStr, "copysign")) ||
-           (NameLen == 9 && !strcmp(NameStr, "copysignf")))) {
+    if (!F->hasLocalLinkage() && F->hasName()) {
+      StringRef Name = F->getName();
+      if (Name == "copysign" || Name == "copysignf") {
         if (I.getNumOperands() == 3 &&   // Basic sanity checks.
             I.getOperand(1)->getType()->isFloatingPoint() &&
             I.getType() == I.getOperand(1)->getType() &&
@@ -4455,10 +4452,7 @@
                                    LHS.getValueType(), LHS, RHS));
           return;
         }
-      } else if (NameStr[0] == 'f' &&
-                 ((NameLen == 4 && !strcmp(NameStr, "fabs")) ||
-                  (NameLen == 5 && !strcmp(NameStr, "fabsf")) ||
-                  (NameLen == 5 && !strcmp(NameStr, "fabsl")))) {
+      } else if (Name == "fabs" || Name == "fabsf" || Name == "fabsl") {
         if (I.getNumOperands() == 2 &&   // Basic sanity checks.
             I.getOperand(1)->getType()->isFloatingPoint() &&
             I.getType() == I.getOperand(1)->getType()) {
@@ -4467,10 +4461,7 @@
                                    Tmp.getValueType(), Tmp));
           return;
         }
-      } else if (NameStr[0] == 's' &&
-                 ((NameLen == 3 && !strcmp(NameStr, "sin")) ||
-                  (NameLen == 4 && !strcmp(NameStr, "sinf")) ||
-                  (NameLen == 4 && !strcmp(NameStr, "sinl")))) {
+      } else if (Name == "sin" || Name == "sinf" || Name == "sinl") {
         if (I.getNumOperands() == 2 &&   // Basic sanity checks.
             I.getOperand(1)->getType()->isFloatingPoint() &&
             I.getType() == I.getOperand(1)->getType()) {
@@ -4479,10 +4470,7 @@
                                    Tmp.getValueType(), Tmp));
           return;
         }
-      } else if (NameStr[0] == 'c' &&
-                 ((NameLen == 3 && !strcmp(NameStr, "cos")) ||
-                  (NameLen == 4 && !strcmp(NameStr, "cosf")) ||
-                  (NameLen == 4 && !strcmp(NameStr, "cosl")))) {
+      } else if (Name == "cos" || Name == "cosf" || Name == "cosl") {
         if (I.getNumOperands() == 2 &&   // Basic sanity checks.
             I.getOperand(1)->getType()->isFloatingPoint() &&
             I.getType() == I.getOperand(1)->getType()) {
diff --git a/lib/Transforms/Scalar/SimplifyLibCalls.cpp b/lib/Transforms/Scalar/SimplifyLibCalls.cpp
index 9a5ed45..e48b14c 100644
--- a/lib/Transforms/Scalar/SimplifyLibCalls.cpp
+++ b/lib/Transforms/Scalar/SimplifyLibCalls.cpp
@@ -31,6 +31,7 @@
 #include "llvm/ADT/Statistic.h"
 #include "llvm/Support/Compiler.h"
 #include "llvm/Support/Debug.h"
+#include "llvm/Support/raw_ostream.h"
 #include "llvm/Config/config.h"
 using namespace llvm;
 
@@ -1655,20 +1656,18 @@
         continue;
       
       // Ignore unknown calls.
-      const char *CalleeName = Callee->getNameStart();
-      StringMap<LibCallOptimization*>::iterator OMI =
-        Optimizations.find(StringRef(CalleeName, Callee->getNameLen()));
-      if (OMI == Optimizations.end()) continue;
+      LibCallOptimization *LCO = Optimizations.lookup(Callee->getName());
+      if (!LCO) continue;
       
       // Set the builder to the instruction after the call.
       Builder.SetInsertPoint(BB, I);
       
       // Try to optimize this call.
-      Value *Result = OMI->second->OptimizeCall(CI, TD, Builder);
+      Value *Result = LCO->OptimizeCall(CI, TD, Builder);
       if (Result == 0) continue;
 
-      DEBUG(DOUT << "SimplifyLibCalls simplified: " << *CI;
-            DOUT << "  into: " << *Result << "\n");
+      DEBUG(errs() << "SimplifyLibCalls simplified: " << *CI;
+            errs() << "  into: " << *Result << "\n");
       
       // Something changed!
       Changed = true;