llvm-svn: 84256

Fix bug where array malloc with unexpected computation of the size argument resulted in MallocHelper 
identifying the malloc as a non-array malloc.  This broke GlobalOpt's optimization of stores of mallocs 
to global variables.

The fix is to classify malloc's into 3 categories:
1. non-array mallocs
2. array mallocs whose array size can be determined
3. mallocs that cannot be determined to be of type 1 or 2 and cannot be optimized

getMallocArraySize() returns NULL for category 3, and all users of this function must avoid their 
malloc optimization if this function returns NULL.

Eventually, currently unexpected codegen for computing the malloc's size argument will be supported in
isArrayMalloc() and getMallocArraySize(), extending malloc optimizations to those examples.

llvm-svn: 84199

don't bother every time going around the main worklist.  This speeds up a 
release-asserts opt -std-compile-opts on 403.gcc by about 4% (1.5s).  It
seems to speed up the most expensive instances of instcombine by ~10%.

llvm-svn: 84171

instruction (which disqualifies stores, unreachable, etc) and at least the
first operand is a constant.  This filters out a lot of obvious cases that
can't be folded.  Also, switch the IRBuilder to a TargetFolder, which tries
harder.

llvm-svn: 84170

llvm-svn: 84118

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

llvm-svn: 84001

llvm-svn: 83999

llvm-svn: 83998

for purposes other than inlining.

llvm-svn: 83997

this will increase the likelihood of common code getting sunk towards
the unwind.

llvm-svn: 83996

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

the IR, and to implement the FIXME'd optimization.

llvm-svn: 83748

inserted only once, just use vector.  Don't compute ExitBlocks unless we
need it, change std::sort to array_pod_sort.

llvm-svn: 83747

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: 83745