From 1f6c7fe6a87583eecb49b00b02fbb529f45bac90 Mon Sep 17 00:00:00 2001
From: Chris Lattner <sabre@nondot.org>
Date: Fri, 23 Jan 2009 18:35:48 +0000
Subject: [PATCH] This is a follow-up to r62675:

Refactor how the preprocessor changes a token from being an tok::identifier to a
keyword (e.g. tok::kw_for).  Instead of doing this in HandleIdentifier, hoist this
common case out into the caller, so that every keyword doesn't have to go through
HandleIdentifier.  This drops time in HandleIdentifier from 1.25ms to .62ms, and
speeds up clang -Eonly with PTH by about 1%.

llvm-svn: 62855
---
 clang/include/clang/Basic/IdentifierTable.h | 11 ++---------
 clang/lib/Lex/Lexer.cpp                     |  4 ++++
 clang/lib/Lex/PTHLexer.cpp                  |  6 ++++++
 clang/lib/Lex/Preprocessor.cpp              |  4 ----
 clang/lib/Lex/TokenLexer.cpp                | 11 ++++++++---
 5 files changed, 20 insertions(+), 16 deletions(-)

diff --git a/clang/include/clang/Basic/IdentifierTable.h b/clang/include/clang/Basic/IdentifierTable.h
index a06e9b10807b..56a6f4184852 100644
--- a/clang/include/clang/Basic/IdentifierTable.h
+++ b/clang/include/clang/Basic/IdentifierTable.h
@@ -122,14 +122,7 @@ public:
   /// can be used to cause the lexer to map identifiers to source-language
   /// tokens.
   tok::TokenKind getTokenID() const { return (tok::TokenKind)TokenID; }
-  void setTokenID(tok::TokenKind ID) {
-    TokenID = ID;
-  
-    if (ID != tok::identifier)
-      NeedsHandleIdentifier = 1;
-    else
-      RecomputeNeedsHandleIdentifier();
-  }
+  void setTokenID(tok::TokenKind ID) { TokenID = ID; }
   
   /// getPPKeywordID - Return the preprocessor keyword ID for this identifier.
   /// For example, "define" will return tok::pp_define.
@@ -225,7 +218,7 @@ private:
   void RecomputeNeedsHandleIdentifier() {
     NeedsHandleIdentifier =
       (isPoisoned() | hasMacroDefinition() | isCPlusPlusOperatorKeyword() |
-       isExtensionToken()) || getTokenID() != tok::identifier;
+       isExtensionToken());
   }
 };
 
diff --git a/clang/lib/Lex/Lexer.cpp b/clang/lib/Lex/Lexer.cpp
index fca8fd4eb165..3174a0591745 100644
--- a/clang/lib/Lex/Lexer.cpp
+++ b/clang/lib/Lex/Lexer.cpp
@@ -558,6 +558,10 @@ FinishIdentifier:
     // identifier table.
     IdentifierInfo *II = PP->LookUpIdentifierInfo(Result, IdStart);
     
+    // Change the kind of this identifier to the appropriate token kind, e.g.
+    // turning "for" into a keyword.
+    Result.setKind(II->getTokenID());
+    
     // Finally, now that we know we have an identifier, pass this off to the
     // preprocessor, which may macro expand it or something.
     if (II->isHandleIdentifierCase())
diff --git a/clang/lib/Lex/PTHLexer.cpp b/clang/lib/Lex/PTHLexer.cpp
index b0f06271c4fb..ec76a299845b 100644
--- a/clang/lib/Lex/PTHLexer.cpp
+++ b/clang/lib/Lex/PTHLexer.cpp
@@ -101,7 +101,13 @@ LexNextToken:
   if (IdentifierID) {
     MIOpt.ReadToken();
     IdentifierInfo *II = PTHMgr.GetIdentifierInfo(IdentifierID-1);
+    
     Tok.setIdentifierInfo(II);
+    
+    // Change the kind of this identifier to the appropriate token kind, e.g.
+    // turning "for" into a keyword.
+    Tok.setKind(II->getTokenID());
+    
     if (II->isHandleIdentifierCase())
       PP->HandleIdentifier(Tok);
     return;
diff --git a/clang/lib/Lex/Preprocessor.cpp b/clang/lib/Lex/Preprocessor.cpp
index e53c392c388b..d0a15e45c414 100644
--- a/clang/lib/Lex/Preprocessor.cpp
+++ b/clang/lib/Lex/Preprocessor.cpp
@@ -759,10 +759,6 @@ void Preprocessor::HandleIdentifier(Token &Identifier) {
   if (II.isCPlusPlusOperatorKeyword())
     Identifier.setIdentifierInfo(0);
 
-  // Change the kind of this identifier to the appropriate token kind, e.g.
-  // turning "for" into a keyword.
-  Identifier.setKind(II.getTokenID());
-    
   // If this is an extension token, diagnose its use.
   // We avoid diagnosing tokens that originate from macro definitions.
   if (II.isExtensionToken() && Features.C99 && !DisableMacroExpansion)
diff --git a/clang/lib/Lex/TokenLexer.cpp b/clang/lib/Lex/TokenLexer.cpp
index c945843459f4..dd5352c1b616 100644
--- a/clang/lib/Lex/TokenLexer.cpp
+++ b/clang/lib/Lex/TokenLexer.cpp
@@ -326,9 +326,14 @@ void TokenLexer::Lex(Token &Tok) {
   }
   
   // Handle recursive expansion!
-  if (Tok.getIdentifierInfo() && !DisableMacroExpansion &&
-      Tok.getIdentifierInfo()->isHandleIdentifierCase())
-    PP.HandleIdentifier(Tok);
+  if (IdentifierInfo *II = Tok.getIdentifierInfo()) {
+    // Change the kind of this identifier to the appropriate token kind, e.g.
+    // turning "for" into a keyword.
+    Tok.setKind(II->getTokenID());
+    
+    if (!DisableMacroExpansion && II->isHandleIdentifierCase())
+      PP.HandleIdentifier(Tok);
+  }
 
   // Otherwise, return a normal token.
 }
-- 
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