allow 'make CPPFLAGS=<something>' work again

this makes this hack a bit more bearable
for poor souls who need to pass custom
preprocessor flags to the build process

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@161240 91177308-0d34-0410-b5e6-96231b3b80d8
Don't delete dead code in TwoAddressInstructionPass.

This functionality was added before we started running
DeadMachineInstructionElim on all targets. It serves no purpose now.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@161241 91177308-0d34-0410-b5e6-96231b3b80d8
Delete dead function.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@161242 91177308-0d34-0410-b5e6-96231b3b80d8
Revert previous patch here, we should instead configure in specific
packages for particular uses.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@161246 91177308-0d34-0410-b5e6-96231b3b80d8
Remove a dead prototype.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@161250 91177308-0d34-0410-b5e6-96231b3b80d8
Add a configure option to pass -std=c++11 on the command line.

rdar://11366674

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@161251 91177308-0d34-0410-b5e6-96231b3b80d8
Add support for detecting libxml for Dmitri's work. He'll
commit code in clang that uses this shortly.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@161252 91177308-0d34-0410-b5e6-96231b3b80d8
Add a configure flag for enabling -Werror on the command line
while building as requested by Lang.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@161253 91177308-0d34-0410-b5e6-96231b3b80d8
Make the hasPHIKills flag a computed property.

The VNInfo::HAS_PHI_KILL is only half supported. We precompute it in
LiveIntervalAnalysis, but it isn't properly updated by live range
splitting and functions like shrinkToUses().

It is only used in one place: RegisterCoalescer::removeCopyByCommutingDef().

This patch changes that function to use a new LiveIntervals::hasPHIKill()
function that computes the flag for a given value number.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@161254 91177308-0d34-0410-b5e6-96231b3b80d8
Eliminate the VNInfo::hasPHIKill() flag.

The only real user of the flag was removeCopyByCommutingDef(), and it
has been switched to LiveIntervals::hasPHIKill().

All the code changed by this patch was only concerned with computing and
propagating the flag.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@161255 91177308-0d34-0410-b5e6-96231b3b80d8
Silence unused variable warning in -asserts build

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@161256 91177308-0d34-0410-b5e6-96231b3b80d8
Fix a couple of loops that were processing unused value numbers.

Unused VNInfos should be left alone. Their def SlotIndex doesn't point
to anything.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@161257 91177308-0d34-0410-b5e6-96231b3b80d8
Completely eliminate VNInfo flags.

The 'unused' state of a value number can be represented as an invalid
def SlotIndex. This also exposed code that shouldn't have been looking
at unused value VNInfos.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@161258 91177308-0d34-0410-b5e6-96231b3b80d8
Fix memcmp code-gen to honor -fno-builtin.

I noticed that SelectionDAGBuilder::visitCall was missing a check for memcmp
in TargetLibraryInfo, so that it would use custom code for memcmp calls even
with -fno-builtin.  I also had to add a new -disable-simplify-libcalls option
to llc so that I could write a test for this.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@161262 91177308-0d34-0410-b5e6-96231b3b80d8
Try to reduce the compile time impact of r161232.

The previous change caused fast isel to not attempt handling any calls to
builtin functions.  That included things like "printf" and caused some
noticable regressions in compile time.  I wanted to avoid having fast isel
keep a separate list of functions that had to be kept in sync with what the
code in SelectionDAGBuilder.cpp was handling.  I've resolved that here by
moving the list into TargetLibraryInfo.  This is somewhat redundant in
SelectionDAGBuilder but it will ensure that we keep things consistent.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@161263 91177308-0d34-0410-b5e6-96231b3b80d8
Delete merged physreg copies in joinReservedPhysReg().

Previously, the identity copy would survive through register allocation
before it was removed by the rewriter.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@161269 91177308-0d34-0410-b5e6-96231b3b80d8
Add an experimental -early-live-intervals option.

This option runs LiveIntervals before TwoAddressInstructionPass which
will eventually learn to exploit and update the analysis.

Eventually, LiveIntervals will run before PHIElimination, and we can get
rid of LiveVariables.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@161270 91177308-0d34-0410-b5e6-96231b3b80d8
1. Redo mips16 instructions to avoid multiple opcodes for same instruction.
Change these to patterns.
2. Add another 16 instructions.

Patch by Reed Kotler.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@161272 91177308-0d34-0410-b5e6-96231b3b80d8
Begin adding support for updating LiveIntervals in TwoAddressInstructionPass.

This is far from complete, and only changes behavior when the
-early-live-intervals flag is passed to llc.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@161273 91177308-0d34-0410-b5e6-96231b3b80d8
TwoAddressInstructionPass refactoring: Extract a method.

No functional change intended, except replacing a DenseMap with a
SmallDenseMap which should behave identically.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@161281 91177308-0d34-0410-b5e6-96231b3b80d8