interfaces which could be extracted from it, and must be provided on
construction, to a chained analysis group.

The end goal here is that TTI works much like AA -- there is a baseline
"no-op" and target independent pass which is in the group, and each
target can expose a target-specific pass in the group. These passes will
naturally chain allowing each target-specific pass to delegate to the
generic pass as needed.

In particular, this will allow a much simpler interface for passes that
would like to use TTI -- they can have a hard dependency on TTI and it
will just be satisfied by the stub implementation when that is all that
is available.

This patch is a WIP however. In particular, the "stub" pass is actually
the one and only pass, and everything there is implemented by delegating
to the target-provided interfaces. As a consequence the tools still have
to explicitly construct the pass. Switching targets to provide custom
passes and sinking the stub behavior into the NoTTI pass is the next
step.

llvm-svn: 171621

llvm-svn: 171620

llvm-svn: 171619

interface.

llvm-svn: 171618

the ScalarTargetTransformInfo interface.

llvm-svn: 171617

interface rather than the ScalarTargetTransformInterface.

llvm-svn: 171616

VectorTargetTransformInfo into the TargetTransformInfo pass,
implementing them be delegating back out to the two subobjects.

This is the first step to folding the interfaces together and making
TargetTransformInfo a normal analysis pass (specifically an analysis
group which targets can provide target-specific analysis pass
implementations of).

No callers are migrated here, this just stubs out the interface. Next
step will be to migrate all the callers to directly operate on TTI
instead of STTI or VTTI respectively. That will allow replacing the
machinery for delivering TTI without changing every caller at once.

WIP, I promise all the duplicated interfaces will be removed in the end,
this just decouples the steps of the process.

llvm-svn: 171615

values -- that's not required to fix the bug that was cropping up, and
the values selected made the enumeration's underlying type signed and
introduced some warnings. This fixes the -Werror build.

The underlying issue here was that the DenseMapInfo was casting values
completely outside the range of the underlying storage of the
enumeration to the enumeration's type. GCC went and "optimized" that
into infloops and other misbehavior. By providing designated special
values for these keys in the dense map, we ensure they are indeed
representable and that they won't be used for anything else.

It might be better to reuse None for the empty key and have the
tombstone share the value of the sentinel enumerator, but honestly
having 2 extra enumerators seemed not to matter and this seems a bit
simpler. I'll let Bill shuffle this around (or ask me to shuffle it
around) if he prefers it to look a different way.

I also made the switch a bit more clear (and produce a better assert)
that the enumerators are *never* going to show up and are errors if they
do.

llvm-svn: 171614

unused, there were transitive includes needed.

llvm-svn: 171613

llvm-svn: 171612

IR/Attributes: Provide EmptyKey and TombstoneKey in part of enum, as workaround for gcc-4.4 take #2.

I will investigate, later, what was wrong. I am too tired for now.

llvm-svn: 171611

This change essentially reverts r87069 which came without a test case. It
causes no regressions in the GDB 7.5 test suite & fixes 25 xfails (commit
to the test suite to follow). If anyone can present a test case that
demonstrates why this check is necessary I'd be happy to account for it in one
way or another.

llvm-svn: 171609

Recommit r171461 which was incorrectly reverted. Mark DIV/IDIV instructions hasSideEffects=1 because they can trap when dividing by 0. This is needed to keep early if conversion from moving them across basic blocks.

llvm-svn: 171608

URL: http://llvm.org/viewvc/llvm-project?rev=171524&view=rev
Log:
The current Intel Atom microarchitecture has a feature whereby when a function
returns early then it is slightly faster to execute a sequence of NOP
instructions to wait until the return address is ready,
as opposed to simply stalling on the ret instruction
until the return address is ready.

When compiling for X86 Atom only, this patch will run a pass, called
"X86PadShortFunction" which will add NOP instructions where less than four
cycles elapse between function entry and return.

It includes tests.

Patch by Andy Zhang.

llvm-svn: 171603

llvm-svn: 171601

With DenseMapInfo<Enum>, it is miscompiled on g++-4.4.

    static inline Enum getEmptyKey() { return Enum(<arbitrary int/unsigned value>); }

    isEauql(getEmptyKey(), ...)

The compiler mis-assumes the return value is not aliased to Enum.

llvm-svn: 171600

The series of patches leading up to this one makes llc -O0 run 8% faster.

When deallocating a MachineFunction, there is no need to visit all
MachineInstr and MachineOperand objects to deallocate them. All their
memory come from a BumpPtrAllocator that is about to be purged, and they
have empty destructors anyway.

This only applies when deallocating the MachineFunction.
DeleteMachineInstr() should still be used to recycle MI memory during
the codegen passes.

Remove the LeakDetector support for MachineInstr. I've never seen it
used before, and now it definitely doesn't work. With this patch, leaked
MachineInstrs would be much less of a problem since all of their memory
will be reclaimed by ~MachineFunction().

llvm-svn: 171599

Instead of an std::vector<MachineOperand>, use MachineOperand arrays
from an ArrayRecycler living in MachineFunction.

This has several advantages:

- MachineInstr now has a trivial destructor, making it possible to
  delete them in batches when destroying MachineFunction. This will be
  enabled in a later patch.

- Bypassing malloc() and free() can be faster, depending on the system
  library.

- MachineInstr objects and their operands are allocated from the same
  BumpPtrAllocator, so they will usually be next to each other in
  memory, providing better locality of reference.

- Reduce MachineInstr footprint. A std::vector is 24 bytes, the new
  operand array representation only uses 8+4+1 bytes in MachineInstr.

- Better control over operand array reallocations. In the old
  representation, the use-def chains would be reordered whenever a
  std::vector reached its capacity. The new implementation never changes
  the use-def chain order.

Note that some decisions in the code generator depend on the use-def
chain orders, so this patch may cause different assembly to be produced
in a few cases.

llvm-svn: 171598

This function works like memmove() for MachineOperands, except it also
updates any use-def chains containing the moved operands.

The use-def chains are updated without affecting the order of operands
in the list. That isn't possible when using the
removeRegOperandFromUseList() and addRegOperandToUseList() functions.

Callers to follow soon.

llvm-svn: 171597

legality of an address mode to not use a struct of four values and
instead to accept them as parameters. I'd love to have named parameters
here as most callers only care about one or two of these, but the
defaults aren't terribly scary to write out.

That said, there is no real impact of this as the passes aren't yet
using STTI for this and are still relying upon TargetLowering.

llvm-svn: 171595

next to its only user. This helper relies on TargetLowering information
that shouldn't be generally used throughout the Transfoms library, and
so it made little sense as a generic utility.

This also consolidates the file where we need to remove the remaining
uses of TargetLowering in favor of the IR-layer abstract interface in
TargetTransformInfo.

llvm-svn: 171590

Fixes the CMake build. It took me cutting and pasting this before
I managed to see the missing character. =]

llvm-svn: 171589

and add stack alignment information.

llvm-svn: 171587

The Attribute class is eventually going to represent one attribute. So we need
this class to create the set of attributes. Add some iterator methods to the
builder to access its internal bits in a nice way.

llvm-svn: 171586

llvm-svn: 171584

iLoopVectorize: Non commutative operators can be used as reduction variables as long as the reduction chain is used in the LHS.

PR14803.

llvm-svn: 171583

This should fix clang-native-arm-cortex-a9. Thanks Renato.

llvm-svn: 171582

This is similar to the existing Recycler allocator, but instead of
recycling individual objects from a BumpPtrAllocator, arrays of
different sizes can be allocated.

llvm-svn: 171581

leaving this undefined, and despite the sentence in the standard that
seems to require it, I'll cede the point and assume its a bug in the
wording. Other parts of POSIX regularly allow for things to be -1
instead of undefined, this should too. Makes things more consistent too.

This should have to real impact for folks though.

llvm-svn: 171574

to filcab on IRC for spotting.

llvm-svn: 171573

expression.

llvm-svn: 171571

the source code should now be set up to handle this.

llvm-svn: 171570

if-ed out code paths and on Windows. Hopefully restores the Windows
build. Thanks to Reid Kleckner for helping triage this.

llvm-svn: 171568

llvm-svn: 171567

defines _POSIX_CPUTIME but doesn't support the clock_* functions.

I don't test the value of _POSIX_CPUTIME because the spec merely says
that if it is defined, the CPU-specific timers are available, whereas it
says that _POSIX_TIMERS must be defined and defined to a value greater
than zero. However, this may not work, as the POSIX spec clearly states:

  "If the symbolic constant _POSIX_CPUTIME is defined, then the symbolic
  constant _POSIX_TIMERS shall also be defined by the implementation to
  have the value 200112L."

If this doesn't work, I'll add more hacks for Darwin.

llvm-svn: 171565

llvm-svn: 171559

The bit mask thing will be a thing of the past. It's not extensible enough. Get
rid of its use here. Opt instead for using a vector to hold the attributes.

Note: Some of this code will become obsolete once the rewrite is further along.
llvm-svn: 171553

wall time, user time, and system time since a process started.

For walltime, we currently use TimeValue's interface and a global
initializer to compute a close approximation of total process runtime.

For user time, this adds support for an somewhat more precise timing
mechanism -- clock_gettime with the CLOCK_PROCESS_CPUTIME_ID clock
selected.

For system time, we have to do a full getrusage call to extract the
system time from the OS. This is expensive but unavoidable.

In passing, clean up the implementation of the old APIs and fix some
latent bugs in the Windows code. This might have manifested on Windows
ARM systems or other systems with strange 64-bit integer behavior.

The old API for this both user time and system time simultaneously from
a single getrusage call. While this results in fewer system calls, it
also results in a lower precision user time and if only user time is
desired, it introduces a higher overhead. It may be worthwhile to switch
some of the pass timers to not track system time and directly track user
and wall time. The old API also tracked walltime in a confusing way --
it just set it to the current walltime rather than providing any measure
of wall time since the process started the way buth user and system time
are tracked. The new API is more consistent here.

The plan is to eventually implement these methods for a *child* process
by using the wait3(2) system call to populate an rusage struct
representing the whole subprocess execution. That way, after waiting on
a child process its stats will become accurate and cheap to query.

llvm-svn: 171551

llvm-svn: 171550

because conditions in the next case prevented from doing anything nasty.

llvm-svn: 171549