Twines: Support numeric conversion directly (uitostr, etc).

 - Provides static constructors for doing number to string conversions without
   using temporaries.

 - There are several ways to do this, I think given the Twine constraints this
   is the simplest one.

 - One FIXME for fast number -> hex conversion.

 - Added another comment on one last major bit of perf work Twines need, which
   is to make raw_svector_ostream more efficient.

llvm-svn: 77445

1 files changed, 37 insertions, 11 deletions

diff --git a/llvm/lib/Support/Twine.cpp b/llvm/lib/Support/Twine.cpp
index 4c34d279e8f..c9e5f2401ec 100644
--- a/llvm/lib/Support/Twine.cpp
+++ b/llvm/lib/Support/Twine.cpp
@@ -19,6 +19,13 @@ std::string Twine::str() const {
 }
 
 void Twine::toVector(SmallVectorImpl<char> &Out) const {
+  // FIXME: This is very inefficient, since we are creating a large raw_ostream
+  // buffer -- hitting malloc, which we were supposed to avoid -- all when we
+  // have this pretty little small vector available.
+  //
+  // The best way to fix this is to make raw_svector_ostream do the right thing
+  // and be efficient, by augmenting the base raw_ostream with the ability to
+  // have the buffer managed by a concrete implementation.
   raw_svector_ostream OS(Out);
   print(OS);
 }
@@ -28,6 +35,9 @@ void Twine::printOneChild(raw_ostream &OS, const void *Ptr,
   switch (Kind) {
   case Twine::NullKind: break;
   case Twine::EmptyKind: break;
+  case Twine::TwineKind:
+    static_cast<const Twine*>(Ptr)->print(OS); 
+    break;
   case Twine::CStringKind: 
     OS << static_cast<const char*>(Ptr); 
     break;
@@ -37,8 +47,15 @@ void Twine::printOneChild(raw_ostream &OS, const void *Ptr,
   case Twine::StringRefKind:
     OS << *static_cast<const StringRef*>(Ptr); 
     break;
-  case Twine::TwineKind:
-    static_cast<const Twine*>(Ptr)->print(OS); 
+  case Twine::UDecKind:
+    OS << *static_cast<const uint64_t*>(Ptr);
+    break;
+  case Twine::SDecKind:
+    OS << *static_cast<const int64_t*>(Ptr);
+    break;
+  case Twine::UHexKind:
+    // FIXME: Add raw_ostream functionality for this.
+    OS << ::utohexstr(*static_cast<const uint64_t*>(Ptr));
     break;
   }
 }
@@ -50,21 +67,30 @@ void Twine::printOneChildRepr(raw_ostream &OS, const void *Ptr,
     OS << "null"; break;
   case Twine::EmptyKind:
     OS << "empty"; break;
+  case Twine::TwineKind:
+    OS << "rope:";
+    static_cast<const Twine*>(Ptr)->printRepr(OS);
+    break;
   case Twine::CStringKind:
-    OS << "cstring:\"" 
-       << static_cast<const char*>(Ptr) << "\""; 
+    OS << "cstring:\""
+       << static_cast<const char*>(Ptr) << "\"";
     break;
   case Twine::StdStringKind:
-    OS << "std::string:\"" 
-       << *static_cast<const std::string*>(Ptr) << "\""; 
+    OS << "std::string:\""
+       << static_cast<const std::string*>(Ptr) << "\"";
     break;
   case Twine::StringRefKind:
-    OS << "stringref:\"" 
-       << *static_cast<const StringRef*>(Ptr) << "\""; 
+    OS << "stringref:\""
+       << static_cast<const StringRef*>(Ptr) << "\"";
     break;
-  case Twine::TwineKind:
-    OS << "rope:";
-    static_cast<const Twine*>(Ptr)->printRepr(OS);
+  case Twine::UDecKind:
+    OS << "udec:" << static_cast<const uint64_t*>(Ptr) << "\"";
+    break;
+  case Twine::SDecKind:
+    OS << "sdec:" << static_cast<const int64_t*>(Ptr) << "\"";
+    break;
+  case Twine::UHexKind:
+    OS << "uhex:" << static_cast<const uint64_t*>(Ptr) << "\"";
     break;
   }
 }