Implement Function::getIntrinsicID without it needing to call Value::getName,

which allocates a string.  This speeds up instcombine on 447.dealII by 5%.

llvm-svn: 34318

2 files changed, 10 insertions, 5 deletions

diff --git a/llvm/lib/VMCore/Function.cpp b/llvm/lib/VMCore/Function.cpp
index fcbf73f9cf3..8aa0caa8549 100644
--- a/llvm/lib/VMCore/Function.cpp
+++ b/llvm/lib/VMCore/Function.cpp
@@ -160,12 +160,15 @@ void Function::dropAllReferences() {
 /// llvm/Intrinsics.h.
 ///
 unsigned Function::getIntrinsicID() const {
-  const std::string& Name = this->getName();
-  if (Name.size() < 5 || Name[4] != '.' || Name[0] != 'l' || Name[1] != 'l'
+  const ValueName *ValName = this->getValueName();
+  unsigned Len = ValName->getKeyLength();
+  const char *Name = ValName->getKeyData();
+  
+  if (Len < 5 || Name[4] != '.' || Name[0] != 'l' || Name[1] != 'l'
       || Name[2] != 'v' || Name[3] != 'm')
     return 0;  // All intrinsics start with 'llvm.'
 
-  assert(Name.size() != 5 && "'llvm.' is an invalid intrinsic name!");
+  assert(Len != 5 && "'llvm.' is an invalid intrinsic name!");
 
 #define GET_FUNCTION_RECOGNIZER
 #include "llvm/Intrinsics.gen"
diff --git a/llvm/utils/TableGen/IntrinsicEmitter.cpp b/llvm/utils/TableGen/IntrinsicEmitter.cpp
index faa750daee2..c44ae5e4caa 100644
--- a/llvm/utils/TableGen/IntrinsicEmitter.cpp
+++ b/llvm/utils/TableGen/IntrinsicEmitter.cpp
@@ -81,17 +81,19 @@ EmitFnNameRecognizer(const std::vector<CodeGenIntrinsic> &Ints,
   OS << "// Function name -> enum value recognizer code.\n";
   OS << "#ifdef GET_FUNCTION_RECOGNIZER\n";
   OS << "  switch (Name[5]) {\n";
-  OS << "  default: break;\n";
+  OS << "  default:\n";
   // Emit the intrinsics in sorted order.
   char LastChar = 0;
   for (std::map<std::string, std::string>::iterator I = IntMapping.begin(),
        E = IntMapping.end(); I != E; ++I) {
     if (I->first[5] != LastChar) {
       LastChar = I->first[5];
+      OS << "    break;\n";
       OS << "  case '" << LastChar << "':\n";
     }
     
-    OS << "    if (Name == \"" << I->first << "\") return Intrinsic::"
+    OS << "    if (Len == " << I->first.size()
+       << " && !strcmp(Name, \"" << I->first << "\")) return Intrinsic::"
        << I->second << ";\n";
   }
   OS << "  }\n";