[cfe-commits] r99857 - in /cfe/trunk/lib/CodeGen: CGDebugInfo.cpp CGDebugInfo.h

[Daniel Dunbar]

On Mon, Mar 29, 2010 at 5:27 PM, Ted Kremenek <kremenek at apple.com> wrote:
> Author: kremenek
> Date: Mon Mar 29 19:27:51 2010
> New Revision: 99857
>
> URL: http://llvm.org/viewvc/llvm-project?rev=99857&view=rev
> Log:
> Cache results computed by CGDebugInfo::getOrCreateFile() in a DenseMap.
> This reduces '-c -g' time on one file in 403.gcc by 12%.

Nice!

> Modified:
>    cfe/trunk/lib/CodeGen/CGDebugInfo.cpp
>    cfe/trunk/lib/CodeGen/CGDebugInfo.h
>
> Modified: cfe/trunk/lib/CodeGen/CGDebugInfo.cpp
> URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/CodeGen/CGDebugInfo.cpp?rev=99857&r1=99856&r2=99857&view=diff
> ==============================================================================
> --- cfe/trunk/lib/CodeGen/CGDebugInfo.cpp (original)
> +++ cfe/trunk/lib/CodeGen/CGDebugInfo.cpp Mon Mar 29 19:27:51 2010
> @@ -88,17 +88,35 @@
>
>  /// getOrCreateFile - Get the file debug info descriptor for the input location.
>  llvm::DIFile CGDebugInfo::getOrCreateFile(SourceLocation Loc) {
> -  if (!Loc.isValid())
> +  if (!Loc.isValid())
>     // If Location is not valid then use main input file.
>     return DebugFactory.CreateFile(TheCU.getFilename(), TheCU.getDirectory(),
>                                    TheCU);
>   SourceManager &SM = CGM.getContext().getSourceManager();
>   PresumedLoc PLoc = SM.getPresumedLoc(Loc);
> +
> +  // Cache the results.

Probably worth a note here about why it is safe to cache using the
const char* (which might not be unique) here as a key, its not
completely obvious.

 - Daniel

> +  const char *fname = PLoc.getFilename();
> +  llvm::DenseMap<const char *, llvm::WeakVH>::iterator it =
> +    DIFileCache.find(fname);
> +
> +  if (it != DIFileCache.end()) {
> +    // Verify that the information still exists.
> +    if (&*it->second)
> +      return llvm::DIFile(cast<llvm::MDNode>(it->second));
> +  }
> +
> +  // FIXME: We shouldn't even need to call 'makeAbsolute()' in the cases
> +  // where we can consult the FileEntry.
>   llvm::sys::Path AbsFileName(PLoc.getFilename());
>   AbsFileName.makeAbsolute();
>
> -  return DebugFactory.CreateFile(AbsFileName.getLast(),
> -                                 AbsFileName.getDirname(), TheCU);
> +  llvm::DIFile F = DebugFactory.CreateFile(AbsFileName.getLast(),
> +                                           AbsFileName.getDirname(), TheCU);
> +
> +  DIFileCache[fname] = F.getNode();
> +  return F;
> +
>  }
>  /// CreateCompileUnit - Create new compile unit.
>  void CGDebugInfo::CreateCompileUnit() {
>
> Modified: cfe/trunk/lib/CodeGen/CGDebugInfo.h
> URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/CodeGen/CGDebugInfo.h?rev=99857&r1=99856&r2=99857&view=diff
> ==============================================================================
> --- cfe/trunk/lib/CodeGen/CGDebugInfo.h (original)
> +++ cfe/trunk/lib/CodeGen/CGDebugInfo.h Mon Mar 29 19:27:51 2010
> @@ -64,6 +64,7 @@
>   /// constructed on demand. For example, C++ destructors, C++ operators etc..
>   llvm::BumpPtrAllocator DebugInfoNames;
>
> +  llvm::DenseMap<const char *, llvm::WeakVH> DIFileCache;
>   llvm::DenseMap<const FunctionDecl *, llvm::WeakVH> SPCache;
>   llvm::DenseMap<const NamespaceDecl *, llvm::WeakVH> NameSpaceCache;
>
>
>
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