[opt] Inline a trivial lookup function into the header.

This function is actually *very* hot. It is hard to see currently
because the call graph is very recursive, but I'm working to remove that
and when I do this function becomes significantly higher on the profile
(up to 5%!) and so worth avoiding the call overhead.

No specific perf gain I can measure yet (below the noise), but likely to
have more impact as we stop cluttering the call graph.

Differential Revision: http://reviews.llvm.org/D10788

llvm-svn: 240873

lld/COFF/InputFiles.cpp

@@ -114,10 +114,6 @@ std::error_code ObjectFile::parse() {
   return initializeSymbols();
 }
 
-SymbolBody *ObjectFile::getSymbolBody(uint32_t SymbolIndex) {
-  return SparseSymbolBodies[SymbolIndex]->getReplacement();
-}
-
 std::error_code ObjectFile::initializeChunks() {
   uint32_t NumSections = COFFObj->getNumberOfSections();
   Chunks.reserve(NumSections);

lld/COFF/InputFiles.h

@@ -101,7 +101,9 @@ public:
 
   // Returns a SymbolBody object for the SymbolIndex'th symbol in the
   // underlying object file.
-  SymbolBody *getSymbolBody(uint32_t SymbolIndex);
+  SymbolBody *getSymbolBody(uint32_t SymbolIndex) {
+    return SparseSymbolBodies[SymbolIndex]->getReplacement();
+  }
 
   // Returns the underying COFF file.
   COFFObjectFile *getCOFFObj() { return COFFObj.get(); }