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.

llvm-svn: 161270

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

llvm-svn: 161269

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.

llvm-svn: 161263

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.

llvm-svn: 161262

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.

llvm-svn: 161258

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

llvm-svn: 161257

llvm-svn: 161256

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.

llvm-svn: 161255

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.

llvm-svn: 161254

llvm-svn: 161242

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

llvm-svn: 161241

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

llvm-svn: 161240

Fast isel doesn't currently have support for translating builtin function
calls to target instructions.  For embedded environments where the library
functions are not available, this is a matter of correctness and not
just optimization.  Most of this patch is just arranging to make the
TargetLibraryInfo available in fast isel.  <rdar://problem/12008746>

llvm-svn: 161232

This just provides a way to look up a LibFunc::Func enum value for a
function name.  Alphabetize the enums and function names so we can use a
binary search.

llvm-svn: 161231

llvm-svn: 161230

The "findUsedStructTypes" method is very expensive to run. It needs to be
optimized so that LTO can run faster. Splitting this method out of the Module
class will help this occur. For instance, it can keep a list of seen objects so
that it doesn't process them over and over again.

llvm-svn: 161228

but somehow managed to be dropped later.

Patch by Karel Gardas.

llvm-svn: 161226

llvm-svn: 161222

llvm-svn: 161220

Now that TableGen supports references to NAME w/o it being explicitly
referenced in the definition's own name, use that to simplify
assembly InstAlias definitions in multiclasses.

llvm-svn: 161218

Add more comments and use early returns to reduce nesting in isLoadFoldable.
Also disable folding for V_SET0 to avoid introducing a const pool entry and
a const pool load.

rdar://10554090 and rdar://11873276

llvm-svn: 161207

Previously, def NAME values were only populated, and references to NAME
resolved, when NAME was referenced in the 'def' entry of the multiclass
sub-entry. e.g.,
multiclass foo<...> {
  def prefix_#NAME : ...
}

It's useful, however, to be able to reference NAME even when the default
def name is used. For example, when a multiclass has 'def : Pat<...>'
or 'def : InstAlias<...>' entries which refer to earlier instruction
definitions in the same multiclass. e.g.,
multiclass myMulti<RegisterClass rc> {
  def _r : myI<(outs rc:$d), (ins rc:$r), "r $d, $r", []>;

  def : InstAlias<\"wilma $r\", (!cast<Instruction>(NAME#\"_r\") rc:$r, rc:$r)>;
}

llvm-svn: 161198

Whenever both instruction depths and instruction heights are known in a
block, it is possible to compute the length of the critical path as
max(depth+height) over the instructions in the block.

The stored live-in lists make it possible to accurately compute the
length of a critical path that bypasses the current (small) block.

llvm-svn: 161197

of MipsTargetMachine.cpp.

llvm-svn: 161191

test o32_cc_vararg.ll.

llvm-svn: 161189

Don't cause regunit intervals to be computed just to verify them. Only
check the already cached intervals.

llvm-svn: 161183

LiveRangeEdit::eliminateDeadDefs() can delete a dead instruction that
reads unreserved physregs. This would leave the corresponding regunit
live interval dangling because we don't have shrinkToUses() for physical
registers.

Fix this problem by turning the instruction into a KILL instead of
deleting it. This happens in a landing pad in
test/CodeGen/X86/2012-05-19-CoalescerCrash.ll:

  %vreg27<def,dead> = COPY %EDX<kill>; GR32:%vreg27

becomes:

  KILL %EDX<kill>

An upcoming fix to the machine verifier will catch problems like this by
verifying regunit live intervals.

This fixes PR13498. I am not including the test case from the PR since
we already have one exposing the problem once the verifier is fixed.

llvm-svn: 161182

llvm-svn: 161178

llvm-svn: 161177

llvm-svn: 161171

llvm-svn: 161163

llvm-svn: 161162

llvm-svn: 161161

llvm-svn: 161159

Machine CSE and other optimizations can remove instructions so folding
is possible at peephole while not possible at ISel.

This patch is a rework of r160919 and was tested on clang self-host on my local
machine.

rdar://10554090 and rdar://11873276

llvm-svn: 161152

No functional change.

llvm-svn: 161149

llvm-svn: 161147

llvm-svn: 161143

The height on an instruction is the minimum number of cycles from the
instruction is issued to the end of the trace. Heights are computed for
all instructions in and below the trace center block.

The method for computing heights is different from the depth
computation. As we visit instructions in the trace bottom-up, heights of
used instructions are pushed upwards. This way, we avoid scanning long
use lists, looking for uses in the current trace.

At each basic block boundary, a list of live-in registers and their
minimum heights is saved in the trace block info. These live-in lists
are used when restarting depth computations on a trace that
converges with an already computed trace. They will also be used to
accurately compute the critical path length.

llvm-svn: 161138

llvm-svn: 161134