Add a version of Intrinsic::getName which is more efficient when there are no overloads.

When running 'opt -O2 verify-uselistorder-nodbg.lto.bc', there are 33m allocations.  8.2m
come from std::string allocations in Intrinsic::getName().  Turns out this method only
returns a std::string because it needs to handle overloads, but that is not the common case.

This adds an overload of getName which just returns a StringRef when there are no overloads
and so saves on the allocations.

llvm-svn: 279113

1 files changed, 5 insertions, 0 deletions

diff --git a/llvm/lib/IR/Function.cpp b/llvm/lib/IR/Function.cpp
index f1546f17d9e..90f94e696f3 100644
--- a/llvm/lib/IR/Function.cpp
+++ b/llvm/lib/IR/Function.cpp
@@ -551,6 +551,11 @@ static std::string getMangledTypeStr(Type* Ty) {
   return Result;
 }
 
+StringRef Intrinsic::getName(ID id) {
+  assert(id < num_intrinsics && "Invalid intrinsic ID!");
+  return IntrinsicNameTable[id];
+}
+
 std::string Intrinsic::getName(ID id, ArrayRef<Type*> Tys) {
   assert(id < num_intrinsics && "Invalid intrinsic ID!");
   std::string Result(IntrinsicNameTable[id]);