function so that it can live in Analysis instead of
VMCore.

llvm-svn: 121885

Teach jump threading to "look through" a select when the branch direction of a terminator depends on it.
When it sees a promising select it now tries to figure out whether the condition of the select is known in any of the predecessors and if so it maps the operands appropriately.

llvm-svn: 121859

this case involve a select that simplifies to itself.

llvm-svn: 121817

llvm-svn: 121816

llvm-svn: 121670

llvm-svn: 121362

substitution because it doesn't actually change the IR.  Patch by
Jakub Staszak!

llvm-svn: 121361

The last uses of these functions were removed in r113852 when LazyValueInfo was permanently enabled and removed the need for them.

llvm-svn: 121133

zextOrTrunc(), and APSInt methods extend(), extOrTrunc() and new method
trunc(), to be const and to return a new value instead of modifying the
object in place.

llvm-svn: 121120

Implement jump threading of 'indirectbr' by keeping track of whether we're looking for ConstantInt*s or BlockAddress*s.

llvm-svn: 121066

llvm-svn: 121040

llvm-svn: 121038

memcpy's like:
  memcpy(A, B)
  memcpy(A, C)

we cannot delete the first memcpy as dead if A and C might be aliases.
If so, we actually get:

  memcpy(A, B)
  memcpy(A, A)

which is not correct to transform into:

  memcpy(A, A)

This patch was heavily influenced by Jakub Staszak's patch in PR8728, thanks
Jakub!

llvm-svn: 120974

Should have no functional change other than the order of two transformations that are mutually-exclusive and the exact formatting of debug output.
Internally, it now stores the ConstantInt*s as Constant*s, and actual undef values instead of nulls.

llvm-svn: 120946

llvm-svn: 120945

20040709-1.c from the gcc testsuite.  I was using the size of a
pointer instead of the pointee.  This fixes rdar://8713376

llvm-svn: 120519

llvm-svn: 120498

may-aliasing stores that partially overlap with different base
pointers.  This implements PR6043 and the non-variable part of
PR8657

llvm-svn: 120485

llvm-svn: 120476

llvm-svn: 120474

llvm-svn: 120471

the code.  We now get accurate sizes on Loads, though it surely doesn't
matter in practice.

llvm-svn: 120469

1. if the underlying pointer passed in can be resolved
   to any argument or alloca, then we don't need to scan.
   Previously we would only avoid the scan if the alloca
   or byval was actually considered dead.
2. The dead store processing code is itself completely
   dead and didn't handle volatile stores right anyway,
   so delete it.  This allows simplifying the interface
   to RemoveAccessedObjects.

llvm-svn: 120467

made sense to me.  We now have a set of dead stack objects, and
they become live when loaded.  Fix a theoretical problem where
we'd pass in the wrong pointer to the alias query.

llvm-svn: 120465

If the call might read all the allocas, stop scanning early.
Convert a vector to smallvector, shrink SmallPtrSet to 16 instead
of 64 to avoid crazy linear scans.

llvm-svn: 120463

there should be a better way to do this.  PR 8679.

llvm-svn: 120457

llvm-svn: 120454

AA and MD pass info instead of using getAnalysis<> all over.

llvm-svn: 120453

llvm-svn: 120452

now that DSE hacks on them.  This fixes a regression I introduced,
by generalizing DSE to hack on transfers.

llvm-svn: 120445

about pairs of AA::Location's instead of looking for MemDep's
"Def" predicate.  This is more powerful and general, handling
memset/memcpy/store all uniformly, and implementing PR8701 and
probably obsoleting parts of memcpyoptimizer.

This also fixes an obscure bug with init.trampoline and i8
stores, but I'm not surprised it hasn't been hit yet.  Enhancing
init.trampoline to carry the size that it stores would allow
DSE to be much more aggressive about optimizing them.

llvm-svn: 120406

llvm-svn: 120398

llvm-svn: 120391

remove an actively-wrong comment.

llvm-svn: 120378

It can be seriously improved, but at least now it isn't intertwined
with the other logic.

llvm-svn: 120377

contains "ref".

Enhance DSE to use a modref query instead of a store-specific hack
to generalize the "ignore may-alias stores" optimization to handle
memset and memcpy.

llvm-svn: 120368

stores, fix and add a testcase.

llvm-svn: 120363

1. Don't bother trying to optimize:

lifetime.end(ptr)
store(ptr)

as it is undefined, and therefore shouldn't exist.

2. Move the 'storing a loaded pointer' xform up, simplifying
  the may-aliased store code.

llvm-svn: 120359

llvm-svn: 120347

llvm-svn: 120325