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

llvm-svn: 69754

llvm-svn: 69753

llvm-svn: 69752

some refactoring I did recently to StoreManager.

StoreManager::CastRegion: Handle casts to void* by stripping TypedViewRegions.

llvm-svn: 69751

llvm-svn: 69750

practical benefit in the case of ScalarEvolution, and it's otherwise
a nuisance.

llvm-svn: 69749

llvm-svn: 69748

llvm-svn: 69747

r56595 timeframe, but left undone.  Radar 6812711

llvm-svn: 69745

name lookup of structures declared within other structures.

llvm-svn: 69744

This fixes a very subtle bug. vr defined by an implicit_def is allowed overlap with any register since it doesn't actually modify anything. However, if it's used as a two-address use, its live range can be extended and it can be spilled. The spiller must take care not to emit a reload for the vn number that's defined by the implicit_def. This is both a correctness and performance issue.

llvm-svn: 69743

working on the previous fix.

llvm-svn: 69742

Fix: <rdar://problem/6777209> false Dereference of null pointer in loop: pointer increment/decrement preserves non-nullness

When the StoreManager doesn't reason well about pointer-arithmetic, propagate
the non-nullness constraint on a pointer value when performing pointer
arithmetic uisng ++/--.

llvm-svn: 69741

llvm-svn: 69740

unit into the PCH file, since we won't be performing name lookup into
it anyway. Reduces the size of the Carbon.h PCH file by ~200k.

llvm-svn: 69739

mark exactly the blocks which have references that are "live through".
This fixes a rejects valid: 
rdar://6808730 - [sema] [blocks] block rejected at global scope

llvm-svn: 69738

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

llvm-svn: 69731

into StoreManager::CastRegion. Both methods were practically identical, and this
is core logic that is common to all StoreManagers since it defines the basic
invariants of the abstract memory model.

llvm-svn: 69730

llvm-svn: 69729

@implementation that closes a @class delcaration.
 - I don't know how to make a test case for this, but this strengthens
   the invariants that hold internally. The functionality change here
   is the edit to SemaDeclObjC.cpp.

llvm-svn: 69728

llvm-svn: 69727

llvm-svn: 69721

llvm-svn: 69720

pieces.

llvm-svn: 69719

llvm-svn: 69710

type to truncate to should be the number of bits of the value that are
preserved, not the number that are clobbered with sign-extension.
This fixes regressions in ldecod.

llvm-svn: 69704

llvm-svn: 69703

the build).

llvm-svn: 69702

in non-fragile abi mode.  rdar://6811884

llvm-svn: 69701

Should now work when building with objdir != srcdir and when llvm-gcc is not
available.

Thanks to Duncan Sands for testing and advice!

llvm-svn: 69700

llvm-svn: 69699

llvm-svn: 69697

llvm-svn: 69695

llvm-svn: 69694

llvm-svn: 69688

in cases like this:

typedef struct {
  short instance;
  char name[0];
} ATTR_LIST_ENTRY2;

void test() {
  ATTR_LIST_ENTRY2 X = (ATTR_LIST_ENTRY2) { .instance = 7, };
}  

While it is safe to emit them, it is pretty silly.

llvm-svn: 69687

layered regions.

llvm-svn: 69686

llvm-svn: 69684