file needs to store. CodeGen needs to see these definitions (via
HandleTopLevelDecl), otherwise it won't be able to generate code for
them.
This patch notifies the consumer (e.g., CodeGen) about function
definitions and variable definitions when the corresponding
declarations are deserialized. Hence, we don't eagerly deserialize the
declarations for every variable or function that has a definition in
the PCH file. This gives another 5% speedup for the Carbon-prefixed
"Hello, World!", and brings our PCH statistics down to something far
more reasonable:
*** PCH Statistics:
13/20693 types read (0.062823%)
17/59230 declarations read (0.028702%)
54/44914 identifiers read (0.120230%)
0/32954 statements read (0.000000%)
5/6187 macros read (0.080815%)
llvm-svn: 69820
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.
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
with its prefix header. We're also reading less of the PCH file for
"Hello, World!":
*** 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%)
down from
*** PCH Statistics:
411/20693 types read (1.986179%)
2553/59230 declarations read (4.310316%)
1093/44646 identifiers read (2.448148%)
1/32954 statements read (0.003035%)
21/6187 macros read (0.339421%)
llvm-svn: 69815
This optimization improves performance on the Carbon-prefixed "Hello,
World!" example by 57%. For reference, we're now about 2.25x faster
than GCC PCH. We're also pulling in far less of the PCH file:
*** PCH Statistics:
411/20693 types read (1.986179%)
2553/59230 declarations read (4.310316%)
1093/44646 identifiers read (2.448148%)
1/32954 statements read (0.003035%)
21/6187 macros read (0.339421%)
llvm-svn: 69755
identifiers from a precompiled header.
This patch changes the primary name lookup method for entities within
a precompiled header. Previously, we would load all of the names of
declarations at translation unit scope into a large DenseMap (inside
the TranslationUnitDecl's DeclContext), and then perform a special
"last resort" lookup into this DeclContext when we knew there was a
PCH file (see Sema::LookupName). Now, when we see an identifier named
for the first time, we load all of the declarations with that name
that are visible from the translation unit into the IdentifierInfo's
chain of declarations. Thus, the explicit "look into the translation
unit's DeclContext" code is gone, and Sema effectively uses the same
IdentifierInfo-based name lookup mechanism whether we are using a PCH
file or not.
This approach should help PCH scale with the size of the input program
rather than the size of the PCH file. The "Hello, World!" application
with Carbon.h as a PCH file now loads 20% of the identifiers in the
PCH file rather than 85% of the identifiers.
90% of the 20% of identifiers loaded are actually loaded when we
deserialize the preprocessor state. The next step is to make the
preprocessor load macros lazily, which should drastically reduce the
number of types, declarations, and identifiers loaded for "Hello,
World".
llvm-svn: 69737
that also includes the contents of the IdentifierInfo itself (the
various fields and flags, along with the chain of identifiers visible
at the top level that have that name).
We don't make any use of the hash table yet, except that our
identifier ID -> string mapping points into the hash table now.
llvm-svn: 69625
also gets access to the Sema object performing semantic analysis. This
will be used by the PCH writer to serialize Sema state.
No functionality change.
llvm-svn: 69595
AST context's __builtin_va_list type will be set when the PCH file is
loaded. This fixes the crash when CodeGen'ing a va_arg expression
pulled in from a PCH file.
llvm-svn: 69421
lazy PCH deserialization. Propagate that argument wherever it needs to
be. No functionality change, except that I've tightened up a few PCH
tests in preparation.
llvm-svn: 69406
Douglas Gregor