This patch will optimize the following
        movq    %rdi, %rax
        subq    %rsi, %rax
        cmovsq  %rsi, %rdi
        movq    %rdi, %rax
to
        cmpq    %rsi, %rdi
        cmovsq  %rsi, %rdi
        movq    %rdi, %rax

Perform this optimization if the actual result of SUB is not used.

rdar: 11540023
llvm-svn: 157755

It helps compile exotic inline asm. In the test case, normal GR32
virtual registers use up eax-edx so the final GR32_ABCD live range has
no registers left. Since all the live ranges were tiny, we had no way of
prioritizing the smaller register class.

This patch allows tiny unspillable live ranges to be evicted by tiny
unspillable live ranges from a smaller register class.

<rdar://problem/11542429>

llvm-svn: 157715

Switch the canonical FMA term operand order to match both the comment I wrote and the usual LLVM convention.

llvm-svn: 157708

llvm-svn: 157707

llvm-svn: 157706

An empty list is not represented as a null pointer. Let TRI do its own
shortcuts.

llvm-svn: 157702

llvm-svn: 157663

If-converter models predicated defs as read + write. The read should be marked as 'undef' since it may not already be live. This appeases -verify-machineinstrs.

llvm-svn: 157662

Besides adding the new insertPass function, this patch uses it to
enhance the existing -print-machineinstrs so that the MachineInstrs
after a specific pass can be printed.

Patch by Bin Zeng!

llvm-svn: 157655

llvm-svn: 157640

ranges for the instruction about to be bundled. This fixes a bug in an external
project where an assertion was triggered due to spurious 'multiple defs' within
the bundle.

Patch by Ivan Llopard. Thanks Ivan!

llvm-svn: 157632

llvm-svn: 157612

llvm-svn: 157594

Implemented IntItem - the wrapper around APInt. Why not to use APInt item directly right now?
1. It will very difficult to implement case ranges as series of small patches. We got several large and heavy patches. Each patch will about 90-120 kb. If you replace ConstantInt with APInt in SwitchInst you will need to changes at the same time all Readers,Writers and absolutely all passes that uses SwitchInst.
2. We can implement APInt pool inside and save memory space. E.g. we use several switches that works with 256 bit items (switch on signatures, or strings). We can avoid value duplicates in this case.
3. IntItem can be easyly easily replaced with APInt.
4. Currenly we can interpret IntItem both as ConstantInt and as APInt. It allows to provide SwitchInst methods that works with ConstantInt for non-updated passes.

Why I need it right now? Currently I need to update SimplifyCFG pass (EqualityComparisons). I need to work with APInts directly a lot, so peaces of code
ConstantInt *V = ...;
if (V->getValue().ugt(AnotherV->getValue()) {
  ...
}
will look awful. Much more better this way:
IntItem V = ConstantIntVal->getValue();
if (AnotherV < V) {
}

Of course any reviews are welcome.

P.S.: I'm also going to rename ConstantRangesSet to IntegersSubset, and CRSBuilder to IntegersSubsetMapping (allows to map individual subsets of integers to the BasicBlocks).
Since in future these classes will founded on APInt, it will possible to use them in more generic ways.

llvm-svn: 157576

definition in the map before calling itself to retrieve the
DIE for the declaration.  Without this change, if this causes
getOrCreateSubprogramDIE to be recursively called on the definition,
it will create multiple DIEs for that definition.  Fixes PR12831.

llvm-svn: 157541

llvm-svn: 157527

This is obviosly right but I don't see how to do this with proper vector
iterators without building a horrible mess of workarounds.

llvm-svn: 157526

vector.begin()-1 is invalid too.

llvm-svn: 157525

Found by libstdc++'s debug mode.

llvm-svn: 157522

SelectionDAGBuilder: When emitting small compare chains for switches order them by using edge weights.

SimplifyCFG tends to form a lot of 2-3 case switches when merging branches. Move
the most likely condition to the front so it is checked first and the others can
be skipped. This is currently not as effective as it could be because SimplifyCFG
destroys profiling metadata when merging branches and switches. Merging branch
weight metadata is tricky though.

This code touches at most 3 cases so I didn't use a proper sorting algorithm.

llvm-svn: 157521

Negative cycles are filtered out earlier.

llvm-svn: 157514

to pass around a struct instead of a large set of individual values.  This
cleans up the interface and allows more information to be added to the struct
for future targets without requiring changes to each and every target.

NV_CONTRIB

llvm-svn: 157479

llvm-svn: 157455

llvm-svn: 157446

llvm-svn: 157438

(except the part about choosing direction)

llvm-svn: 157437

llvm-svn: 157429

llvm-svn: 157428

The Hazard checker implements in-order contraints, or interlocked
resources. Ready instructions with hazards do not enter the available
queue and are not visible to other heuristics.

The major code change is the addition of SchedBoundary to encapsulate
the state at the top or bottom of the schedule, including both a
pending and available queue.

The scheduler now counts cycles in sync with the hazard checker. These
are minimum cycle counts based on known hazards.

Targets with no itinerary (x86_64) currently remain at cycle 0. To fix
this, we need to provide some maximum issue width for all targets. We
also need to add the concept of expected latency vs. minimum latency.

llvm-svn: 157427

llvm-svn: 157426

llvm-svn: 157425

llvm-svn: 157424

llvm-svn: 157423

llvm-svn: 157422

llvm-svn: 157377

Live ranges with a constrained register class may benefit from splitting
around individual uses. It allows the remaining live range to use a
larger register class where it may allocate. This is like spilling to a
different register class.

This is only attempted on constrained register classes.

<rdar://problem/11438902>

llvm-svn: 157354

llvm-svn: 157349

llvm-svn: 157348

Now that the coalescer keeps live intervals and machine code in sync at
all times, it needs to deal with identity copies differently.

When merging two virtual registers, all identity copies are removed
right away. This means that other identity copies must come from
somewhere else, and they are going to have a value number.

Deal with such copies by merging the value numbers before erasing the
copy instruction. Otherwise, we leave dangling value numbers in the live
interval.

This fixes PR12927.

llvm-svn: 157340

llvm-svn: 157319