Change PHINodes to store simple pointers to their incoming basic blocks,
instead of full-blown Uses.

Note that this loses an optimization in SplitCriticalEdge(), because we
can no longer walk the use list of a BasicBlock to find phi nodes. See
the comment I removed starting "However, the foreach loop is slow for
blocks with lots of predecessors".

Extend replaceAllUsesWith() on a BasicBlock to also update any phi
nodes in the block's successors. This mimics what would have happened
when PHINodes were proper Users of their incoming blocks. (Note that
this only works if OldBB->replaceAllUsesWith(NewBB) is called when
OldBB still has a terminator instruction, so it still has some
successors.)

llvm-svn: 133435

Change various bits of code to make better use of the existing PHINode
API, to insulate them from forthcoming changes in how PHINodes store
their operands.

llvm-svn: 133434

I don't think the AugmentedUse struct buys us much, either in
correctness or in ease of use. Ditch it, and simplify Use::getUser() and
User::allocHungoffUses().

llvm-svn: 133433

* Don't introduce a duplicated bb in the CFG
* When making a branch unconditional, clear the PredCond array so that it
  is really unconditional.

llvm-svn: 133432

dragonegg buildbots back to life.  Original commit message:
Teach early dup how to duplicate basic blocks with one successor and only phi instructions
into more complex blocks.

llvm-svn: 133430

source vector type is to be split while the target vector is to be promoted.
(eg: <4 x i64> -> <4 x i8> )

llvm-svn: 133424

Fix MSVC build. next() function already exists in the MSVC headers. This create a overload conflict. Make sure we pick up the llvm one.

llvm-svn: 133416

into more complex blocks.

llvm-svn: 133415

all over the place in different styles and variants.  Standardize on two
preferred entrypoints: one that takes a StructType and ArrayRef, and one that
takes StructType and varargs.

In cases where there isn't a struct type convenient, we now add a
ConstantStruct::getAnon method (whose name will make more sense after a few
more patches land).  

It would be "really really nice" if the ConstantStruct::get and 
ConstantVector::get methods didn't make temporary std::vectors.

llvm-svn: 133412

equality check.

llvm-svn: 133409

A RegisterTuples instance is used to synthesize super-registers by
zipping together lists of sub-registers. This is useful for generating
pseudo-registers representing register sequence constraints like 'two
consecutive GPRs', or 'an even-odd pair of floating point registers'.

The RegisterTuples def can be used in register set operations when
building register classes. That is the only way of accessing the
synthesized super-registers.

For example, the ARM QQ register class of pseudo-registers could have
been formed like this:

  // Form pairs Q0_Q1, Q2_Q3, ...
  def QQPairs : RegisterTuples<[qsub_0, qsub_1],
                               [(decimate QPR, 2),
                                (decimate (shl QPR, 1), 2)]>;

  def QQ : RegisterClass<..., (add QQPairs)>;

Similarly, pseudo-registers representing '3 consecutive D-regs with
wraparound' look like:

  // Form D0_D1_D2, D1_D2_D3, ..., D30_D31_D0, D31_D0_D1.
  def DSeqTriples : RegisterTuples<[dsub_0, dsub_1, dsub_2],
                                   [(rotl DPR, 0),
                                    (rotl DPR, 1),
                                    (rotl DPR, 2)]>;

TableGen automatically computes aliasing information for the synthesized
registers.

Register tuples are still somewhat experimental. We still need to see
how they interact with MC.

llvm-svn: 133407

const Constant *.

llvm-svn: 133400

llvm-svn: 133390

llvm-svn: 133389

llvm-svn: 133388

instead of scalarizing, and doing an element-by-element truncat.

llvm-svn: 133382

llvm-svn: 133381

expressions, but Chris wants to instead reduce the set of possible constant
expression types.

llvm-svn: 133374

can manipulate instructions and constantexpr's uniformly. No users yet though.

llvm-svn: 133373

top level type without a specified number.  This syntax isn't documented
and blocks forward progress.

llvm-svn: 133371

llvm-svn: 133369

top level type without a specified number.  This asmprinter has never
generated this, as you can tell by no tests being updated.  It also isn't
documented.

llvm-svn: 133368

much cleaner.

llvm-svn: 133364

llvm-svn: 133363

llvm-svn: 133362

now that Type::getDescription() is dead, the TypePrinting class can move from Assembly/Writer.h to being 
a private class in AsmWriter.cpp.

llvm-svn: 133361

removes some gunk from LLVMContext.

llvm-svn: 133360

llvm-svn: 133359

llvm-svn: 133356

temporary std::string for every function being checked.

llvm-svn: 133355

llvm-svn: 133352

llvm-svn: 133351

llvm-svn: 133350

llvm-svn: 133349

llvm-svn: 133348

llvm-svn: 133347

In cases such as the attached test, where the case value for a switch
destination is used in a phi node that follows the destination, it
might be better to replace that value with the condition value of the
switch, so that more blocks can be folded away with
TryToSimplifyUncondBranchFromEmptyBlock because there are less
conflicts in the phi node.

llvm-svn: 133344

llvm-svn: 133339

type's bitwidth matches the (allocated) size of the alloca. This severely
pessimizes vector scalar replacement when the only vector type being used is
something like <3 x float> on x86 or ARM whose allocated size matches a
<4 x float>.

I hope to fix some of the flawed assumptions about allocated size throughout
scalar replacement and reenable this in most cases.

llvm-svn: 133338

for pre-2.9 bitcode files.  We keep x86 unaligned loads, movnt, crc32, and the
target indep prefetch change.

As usual, updating the testsuite is a PITA.

llvm-svn: 133337