presence of PHI nodes.

llvm-svn: 84103

llvm-svn: 84049

Do not check use_empty() before replaceAllUsesWith(). This gives ValueHandles a chance to get properly updated.

llvm-svn: 84033

manually counting instructions.

llvm-svn: 84016

BasicBlocks, so that it doesn't blindly procede in the presence of
large individual BasicBlocks. This addresses a class of code-size
expansion problems.

llvm-svn: 83992

llvm-svn: 83908

llvm-svn: 83870

it to visit instructions from the start of the function to the
end of the function in the first path.  This greatly speeds up
some pathological cases (e.g. PR5150).

Try #3, this time with some unneeded debug info stuff removed
which was causing dead pointers to be added to the worklist.

llvm-svn: 83818

llvm-svn: 83817

it to visit instructions from the start of the function to the
end of the function in the first path.  This greatly speeds up
some pathological cases (e.g. PR5150). 

llvm-svn: 83814

into a shuffle even if it was used by another insertelement.  If the
visitation order of instcombine was wrong, this would turn a chain of
insertelements into a chain of shufflevectors, which was quite painful.

Since CollectShuffleElements handles these cases, the code can just
be nuked.

llvm-svn: 83810

new testcase.

llvm-svn: 83799

llvm-svn: 83797

llvm-svn: 83795

input the the mul is a zext from bool, just that it is all zeros
other than the low bit.  This fixes some phase ordering issues
that would cause us to miss some xforms in mul.ll when the worklist
is visited differently.

llvm-svn: 83794

llvm-svn: 83792

llvm-svn: 83791

it to visit instructions from the start of the function to the
end of the function in the first path.  This greatly speeds up
some pathological cases (e.g. PR5150). 

llvm-svn: 83790

here.

llvm-svn: 83789

For now the metadata of sinked/hoisted instructions is still wrong, but that'll
be fixed when instructions will have debug metadata directly attached.

llvm-svn: 83786

now-probably-dead instruction tree feeding it.

llvm-svn: 83778

gets but clang doesn't, because it is implemented in GCC's
fold routine.

llvm-svn: 83761

done by condprop, but do it in a much more general form.  The
basic idea is that we can do a limited form of tail duplication
in the case when we have a branch on a phi.  Moving the branch
up in to the predecessor block makes instruction selection
much easier and encourages chained jump threadings.

llvm-svn: 83759

llvm-svn: 83756

llvm-svn: 83755

llvm-svn: 83754

from GVN, this also speeds it up, inserts fewer PHI nodes (see the
testcase) and allows it to remove more loads (due to fewer PHI nodes
standing in the way).

llvm-svn: 83746

llvm-svn: 83742

DemoteRegToStack.  This makes it more efficient (because it isn't
creating a ton of load/stores that are eventually removed by a later
mem2reg), and more slightly more effective (because those load/stores
don't get in the way of threading).

llvm-svn: 83706

llvm-svn: 83701

to declare that they preserve other passes without needing to pull in
additional header file or library dependencies. Convert MachineFunctionPass
and CodeGenLICM to make use of this.

llvm-svn: 83555

already on the worklist, and print Visited when an instruction is about to be
visited.  Net, on one input, this reduced the output size by at least 9x.

llvm-svn: 83510

llvm-svn: 83489

llvm-svn: 83404

out of it, and jump threading, condprop and gvn are now getting
most of the benefit.  This was approved by Nicholas and Nicolas.

llvm-svn: 83390

where the element is of a basic builtin type.  For example, to get
an i8* use getInt8PtrTy.

llvm-svn: 83379

ConstantFoldLoadThroughGEPConstantExpr.

llvm-svn: 83311

llvm-svn: 83310

the new predicates I added) instead of going through a context and doing a
pointer comparison.  Besides being cheaper, this allows a smart compiler
to turn the if sequence into a switch.

llvm-svn: 83297

This fixes PR5130.

llvm-svn: 83290