internally.  This is just a cleanup that reduces the need to cast to
unsigned char before assembling a larger integer.

llvm-svn: 62442

llvm-svn: 62424

the implementation of PTHManager::getSpelling.

llvm-svn: 62408

"FileID" a concept that is now enforced by the compiler's type checker
instead of yet-another-random-unsigned floating around.

This is an important distinction from the "FileID" currently tracked by
SourceLocation.  *That* FileID may refer to the start of a file or to a
chunk within it.  The new FileID *only* refers to the file (and its 
#include stack and eventually #line data), it cannot refer to a chunk.

FileID is a completely opaque datatype to all clients, only SourceManager
is allowed to poke and prod it.

llvm-svn: 62407

the "physical" location of tokens, refer to the "spelling" location.
This is more concrete and useful, tokens aren't really physical objects!

llvm-svn: 62309

llvm-svn: 62277

- IdentifierInfo can now (optionally) have its string data not be
  co-located with itself.  This is for use with PTH.  This aspect is a
  little gross, as getName() and getLength() now make assumptions
  about a possible alternate representation of IdentifierInfo.
  Perhaps we should make IdentifierInfo have virtual methods?

IdentifierTable:
- Added class "IdentifierInfoLookup" that can be used by
  IdentifierTable to perform "string -> IdentifierInfo" lookups using
  an auxilliary data structure.  This is used by PTH.
- Perform tests show that IdentifierTable::get() does not slow down
  because of the extra check for the IdentiferInfoLookup object (the
  regular StringMap lookup does enough work to mitigate the impact of
  an extra null pointer check).
- The upshot is that now that some IdentifierInfo objects might be
  owned by the IdentiferInfoLookup object.  This should be reviewed.

PTH:
- Modified PTHManager::GetIdentifierInfo to *not* insert entries in
  IdentifierTable's string map, and instead create IdentifierInfo
  objects on the fly when mapping from persistent IDs to
  IdentifierInfos.  This saves a ton of work with string copies,
  hashing, and StringMap lookup and resizing.  This change was
  motivated because when processing source files in the PTH cache we
  don't need to do any string -> IdentifierInfo lookups.
- PTHManager now subclasses IdentifierInfoLookup, allowing clients of
  IdentifierTable to transparently use IdentifierInfo objects managed
  by the PTH file.  PTHManager resolves "string -> IdentifierInfo"
  queries by doing a binary search over a sorted table of identifier
  strings in the PTH file (the exact algorithm we use can be changed
  as needed).

These changes lead to the following performance changes when using PTH on Cocoa.h:
- fsyntax-only: 10% performance improvement
- Eonly: 30% performance improvement

llvm-svn: 62273

lexical order of the corresponding identifier strings. This will be used for a
forthcoming optimization. This slows down PTH generation time by 7%. We can
revert this change if the optimization proves to not be valuable.

llvm-svn: 62248

- Use canonical FileID when using getSpelling() caching.  This
  addresses some cache misses we were seeing with -fsyntax-only on
  Cocoa.h
- Added Preprocessor::getPhysicalCharacterAt() utility method for
  clients to grab the first character at a specified sourcelocation.
  This uses the PTH spelling cache.
- Modified Sema::ActOnNumericConstant() to use
  Preprocessor::getPhysicalCharacterAt() instead of
  SourceManager::getCharacterData() (to get PTH hits).

These changes cause -fsyntax-only to not page in any sources from
Cocoa.h.  We see a speedup of 27%.

llvm-svn: 62193

llvm-svn: 62187

PTH: Fix remaining cases where the spelling cache in the PTH file was being missed when it shouldn't.  This shaves another 7% off PTH time for -Eonly on Cocoa.h

llvm-svn: 62186

- Refactor caching logic into a helper class PTHSpellingSearch
- Allow "random accesses" in the spelling cache, thus catching the remaining
  cases where 'getSpelling' wasn't hitting the PTH cache
  
For -Eonly, PTH, Cocoa.h:
- This reduces wall time by 3% (user time unchanged, sys time reduced)
- This reduces the amount of paged source by 1112K.
  The remaining 1112K still being paged in is from somewhere else
  (investigating).

llvm-svn: 62009

llvm-svn: 61961

performance gain. Here's what we see for -Eonly on Cocoa.h (using PTH):

- wall time decreases by 21% (26% speedup overall)
- system time decreases by 35%
- user time decreases by 6%

These reductions are due to not paging source files just to get spellings for
literals. The solution in place doesn't appear to be 100% yet, as we still see
some of the pages for source files getting mapped in. Using -print-stats, we see
that SourceManager maps in 7179K less bytes of source text (reduction of 75%).
Will investigate why the remaining 25% are getting paged in.

With these changes, here's how PTH compares to non-PTH on Cocoa.h:
  -Eonly: PTH takes 64% of the time as non-PTH (54% speedup)
  -fsyntax-only: PTH takes 89% of the time as non-PTH (11% speedup)

llvm-svn: 61913

- Added stub PTHLexer::getSpelling() that will be used for fetching cached
  spellings from the PTH file.  This doesn't do anything yet.
- Added a hook in Preprocessor::getSpelling() to call PTHLexer::getSpelling()
  when using a PTHLexer.
- Updated PTHLexer to read the offsets of spelling tables in the PTH file.

llvm-svn: 61911

PTH: Remove some methods and simplify some conditions in PTHLexer::Lex().  No big functionality change.

llvm-svn: 61381

- This reduces the PTH size for Cocoa.h by 7%.
- The increases PTH -Eonly speed for Cocoa.h by 0.8%.

llvm-svn: 61377

llvm-svn: 61375

- Encode the token length with 2 bytes instead of 4.
- This reduces the size of the .pth file for Cocoa.h by 12%.
- This speeds up PTH time (-Eonly) on Cocoa.h by 1.6%.

llvm-svn: 61364

- In PTHLexer::Lex read all of the token data from PTH file before
  constructing the token.  The idea is to enhance locality.
- Do not use Read8/Read32 in PTHLexer::Lex.  Inline these operations manually.
- Change PTHManager::ReadIdentifierInfo() to PTHManager::GetIdentifierInfo().
  They are functionally the same except that PTHLexer::Lex() reads the
  persistent id.

These changes result in a 3.3% speedup for PTH on Cocoa.h (-Eonly).

llvm-svn: 61363

- Embed 'eom' tokens in PTH file.
- Use embedded 'eom' tokens to not lazily generate them in the PTHLexer.
  This means that PTHLexer can always advance to the next token after
  reading a token (instead of buffering tokens using a copy).
- Moved logic of 'ReadToken' into Lex.  GetToken & ReadToken no longer exist.
- These changes result in a 3.3% speedup (-Eonly) on Cocoa.h.
- The code is a little gross.  Many cleanups are possible and should be done.

llvm-svn: 61360

llvm-svn: 61205

Rewrite PTHLexer::DiscardToEndOfLine() to not use GetToken and instead only read the bytes needed to determine if a token is not at the start of the line.

llvm-svn: 61172

Change PTHLexer::getSourceLocation() to not call GetToken() and instead just read the file offset in the token data buffer directly.

llvm-svn: 61170

llvm-svn: 61152

llvm-svn: 61145

PTH: Added minor 'sibling jumping' optimization for iterating over the side table used for fast preprocessor block skipping.  This has a minor performance improvement when preprocessing Cocoa.h, but can have some wins in pathologic cases.

llvm-svn: 60966

Added PTH optimization to not process entire blocks of tokens that appear in skipped preprocessor blocks.  This improves PTH speed by 6%.  The code for this optimization itself is not very optimized, and will get cleaned up.

llvm-svn: 60956

- Added a side-table per each token-cached file with the preprocessor conditional stack.  This tracks what #if's are matched with what #endifs and where their respective tokens are in the PTH file.  This will allow for quick skipping of excluded conditional branches in the Preprocessor.
- Performance testing shows the addition of this information (without actually utilizing it) leads to no performance regressions.

llvm-svn: 60911

PTHLexer: Keep track of the location of the last '#' token and provide the means to jump ahead in the token stream.

llvm-svn: 60905

llvm-svn: 60896

Declare PerIDCache as IdentifierInfo** instead of void*.  This is just cleaner.  No performance change.

llvm-svn: 60843

llvm-svn: 60559

llvm-svn: 60556

Use an array instead of a DenseMap to cache persistent IDs -> IdentifierInfo*.  This leads to a 4% speedup at -fsyntax-only using PTH.

llvm-svn: 60452

- Remove PTHManager.cpp.  Move all of its functions to PTHLexer.cpp since some of the internal methods are used by PTHLexer (their implementations are intertwined.)  This enables some important inlining opportunities at -O3.

- Don't construct an std::vector<Token> prior to feeding PTH tokens to the Preprocessor.  Stream them off the PTH file directly.

llvm-svn: 60447

llvm-svn: 60136

In PTHLexer::DiscardToEndOfLine() use Lex() instead of AdvanceToken().  This handles transitions in the preprocessor state.

llvm-svn: 59845

- Move out logic for handling the end-of-file to LexEndOfFile (to match the Lexer) class.  The logic now mirrors the Lexer class more, which allows us to pass most of the Preprocessor test cases.

llvm-svn: 59768

- Move PTHLexer::GetToken() to be inside PTHLexer.cpp.
- When lexing in raw mode, null out identifiers.

llvm-svn: 59744