[cfe-commits] r69815 - in /cfe/trunk: include/clang/AST/ASTContext.h include/clang/AST/Builtins.h include/clang/Frontend/PCHWriter.h lib/AST/ASTContext.cpp lib/AST/Builtins.cpp lib/Frontend/PCHReader.cpp lib/Frontend/PCHWriter.cpp tools/clang-cc/clang-cc.cpp

[Chris Lattner]

On Apr 22, 2009, at 11:49 AM, Douglas Gregor wrote:
> URL: http://llvm.org/viewvc/llvm-project?rev=69815&view=rev
> Log:
> Lazy loading of builtins for precompiled headers.
>
> PCH files now contain complete information about builtins, including
> any declarations that have been synthesized as part of building the
> PCH file. When using a PCH file, we do not initialize builtins at all;
> when needed, they'll be found in the PCH file.

Very nice, that makes a lot of sense!

> This optimization translations into a 9% speedup for "Hello, World!"
> with Carbon.h as a prefix header and roughly a 5% speedup for 403.gcc

Wow, that's great.

> *** PCH Statistics:
>  286/20693 types read (1.382110%)
>  1630/59230 declarations read (2.751984%)
>  764/44914 identifiers read (1.701029%)
>  1/32954 statements read (0.003035%)
>  5/6187 macros read (0.080815%)

Ok, so why is hello world still pulling in 1630 decls? :)

-Chris