[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

[Douglas Gregor]

On Apr 22, 2009, at 11:58 AM, Chris Lattner wrote:

> 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? :)

See r69820 :)

	- Doug