Commit Graph

179 Commits

Author SHA1 Message Date
Jakob Stoklund Olesen
657720bc6e Don't dereference begin() on an empty vector.
The fix is obvious and the only test case I have is horrible, so I am
not including it. The problem shows up when self-hosting clang on i386
with -new-coalescer enabled.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@164793 91177308-0d34-0410-b5e6-96231b3b80d8
2012-09-27 21:05:59 +00:00
Jakob Stoklund Olesen
01b50ca5b3 Delete dead code.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@163735 91177308-0d34-0410-b5e6-96231b3b80d8
2012-09-12 20:04:17 +00:00
Manman Ren
b720be6a50 Release build: guard dump functions with
"#if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)"

No functional change. Update r163339.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@163653 91177308-0d34-0410-b5e6-96231b3b80d8
2012-09-11 22:23:19 +00:00
Manman Ren
77e300e8f0 Release build: guard dump functions with "ifndef NDEBUG"
No functional change.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@163339 91177308-0d34-0410-b5e6-96231b3b80d8
2012-09-06 19:06:06 +00:00
Jakob Stoklund Olesen
45c5c57179 Allow overlaps between virtreg and physreg live ranges.
The RegisterCoalescer understands overlapping live ranges where one
register is defined as a copy of the other. With this change, register
allocators using LiveRegMatrix can do the same, at least for copies
between physical and virtual registers.

When a physreg is defined by a copy from a virtreg, allow those live
ranges to overlap:

  %CL<def> = COPY %vreg11:sub_8bit; GR32_ABCD:%vreg11
  %vreg13<def,tied1> = SAR32rCL %vreg13<tied0>, %CL<imp-use,kill>

We can assign %vreg11 to %ECX, overlapping the live range of %CL.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@163336 91177308-0d34-0410-b5e6-96231b3b80d8
2012-09-06 18:15:23 +00:00
Jakob Stoklund Olesen
b2beac2b96 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
2012-08-03 20:59:32 +00:00
Jakob Stoklund Olesen
bf60aa9db5 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
2012-08-03 20:19:44 +00:00
Jakob Stoklund Olesen
84315f03cb Preserve 2-addr constraints in ConnectedVNInfoEqClasses.
When a live range splits into multiple connected components, we would
arbitrarily assign <undef> uses to component 0. This is wrong when the
use is tied to a def that gets assigned to a different component:

  %vreg69<def> = ADD8ri %vreg68<undef>, 1

The use and def must get the same virtual register.

Fix this by assigning <undef> uses to the same component as the value
defined by the instruction, if any:

  %vreg69<def> = ADD8ri %vreg69<undef>, 1

This fixes PR13402. The PR has a test case which I am not including
because it is unlikely to keep exposing this behavior in the future.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@160739 91177308-0d34-0410-b5e6-96231b3b80d8
2012-07-25 17:15:15 +00:00
Chandler Carruth
4e996de58c Teach the LiveInterval::join function to use the fast merge algorithm,
generalizing its implementation sufficiently to support this value
number scenario as well.

This cuts out another significant performance hit in large functions
(over 10k basic blocks, etc), especially those with "natural" CFG
structures.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@160026 91177308-0d34-0410-b5e6-96231b3b80d8
2012-07-10 22:25:21 +00:00
Chandler Carruth
1b8da1d8f1 Fix a bug where I didn't test for an empty range before inspecting the
back of it.

I don't have anything even remotely close to a test case for this. It
only broke two build bots, both of them doing bootstrap builds, one of
them a dragonegg bootstrap. It doesn't break for me when I bootstrap
either. It doesn't reproduce every time or on many machines during the
bootstrap. Many thanks to Duncan Sands who got the exact command (and
stage of the bootstrap) which failed on the dragonegg bootstrap and
managed to get it to trigger under valgrind with debug symbols. The fix
was then found by inspection.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@159993 91177308-0d34-0410-b5e6-96231b3b80d8
2012-07-10 15:41:33 +00:00
Chandler Carruth
e585e75612 Add an efficient merge operation to LiveInterval and use it to avoid
quadratic behavior when performing pathological merges. Fixes the core
element of PR12652.

There is only one user of addRangeFrom left: join. I'm hoping to
refactor further in a future patch and have join use this merge
operation as well.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@159982 91177308-0d34-0410-b5e6-96231b3b80d8
2012-07-10 05:16:17 +00:00
Chandler Carruth
261b633089 Teach LiveIntervals how to verify themselves and start using it in some
of the trick merge routines. This adds a layer of testing that was
necessary when implementing more efficient (and complex) merge logic for
this datastructure.

No functionality changed here.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@159981 91177308-0d34-0410-b5e6-96231b3b80d8
2012-07-10 05:06:03 +00:00
Chandler Carruth
95c88b8cb2 Optimize extendIntervalEndTo a tiny bit by saving one call through the
vector erase. No functionality changed.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@159746 91177308-0d34-0410-b5e6-96231b3b80d8
2012-07-05 12:40:45 +00:00
Jakob Stoklund Olesen
b77ec7d264 Simplify LiveInterval::print().
Don't print out the register number and spill weight, making the TRI
argument unnecessary.

This allows callers to interpret the reg field. It can currently be a
virtual register, a physical register, a spill slot, or a register unit.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@158031 91177308-0d34-0410-b5e6-96231b3b80d8
2012-06-05 22:51:54 +00:00
Jakob Stoklund Olesen
4e53a40ea3 Implement LiveRangeCalc::extendToUses() and createDeadDefs().
These LiveRangeCalc methods are to be used when computing a live range
from scratch.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@158027 91177308-0d34-0410-b5e6-96231b3b80d8
2012-06-05 21:54:09 +00:00
Jakob Stoklund Olesen
bd6f44a3a2 Run proper recursive dead code elimination during coalescing.
Dead copies cause problems because they are trivial to coalesce, but
removing them gived the live range a dangling end point. This patch
enables full dead code elimination which trims live ranges to their uses
so end points don't dangle.

DCE may erase multiple instructions. Put the pointers in an ErasedInstrs
set so we never risk visiting erased instructions in the work list.

There isn't supposed to be any dead copies entering RegisterCoalescer,
but they do slip by as evidenced by test/CodeGen/X86/coalescer-dce.ll.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@157101 91177308-0d34-0410-b5e6-96231b3b80d8
2012-05-19 05:25:50 +00:00
Jakob Stoklund Olesen
ff11c01853 Don't update spill weights when joining intervals.
We don't compute spill weights until after coalescing anyway.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@155766 91177308-0d34-0410-b5e6-96231b3b80d8
2012-04-28 19:19:11 +00:00
Jakob Stoklund Olesen
f4aee4c50e Spring cleaning - Delete dead code.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@155765 91177308-0d34-0410-b5e6-96231b3b80d8
2012-04-28 19:19:07 +00:00
Jakob Stoklund Olesen
0aad7d274d Drop the REDEF_BY_EC VNInfo flag.
A live range that has an early clobber tied redef now looks like a
normal tied redef, except the early clobber def uses the early clobber
slot.

This is enough to handle any strange interference problems.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@149769 91177308-0d34-0410-b5e6-96231b3b80d8
2012-02-04 05:51:25 +00:00
Lang Hames
d88710a3e0 Break as soon as the MustMapCurValNos flag is set - no need to reiterate.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@149596 91177308-0d34-0410-b5e6-96231b3b80d8
2012-02-02 06:55:45 +00:00
Lang Hames
02e08d5b4d PR11868. The previous loop in LiveIntervals::join would sometimes fall over if
more than two adjacent ranges needed to be merged. The new version should be
able to handle an arbitrary sequence of adjancent ranges.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@149588 91177308-0d34-0410-b5e6-96231b3b80d8
2012-02-02 05:37:34 +00:00
Jakob Stoklund Olesen
194eb71a11 Use getVNInfoBefore() when it makes sense.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@144517 91177308-0d34-0410-b5e6-96231b3b80d8
2011-11-14 01:39:36 +00:00
Jakob Stoklund Olesen
2debd48ca7 Rename SlotIndexes to match how they are used.
The old naming scheme (load/use/def/store) can be traced back to an old
linear scan article, but the names don't match how slots are actually
used.

The load and store slots are not needed after the deferred spill code
insertion framework was deleted.

The use and def slots don't make any sense because we are using
half-open intervals as is customary in C code, but the names suggest
closed intervals.  In reality, these slots were used to distinguish
early-clobber defs from normal defs.

The new naming scheme also has 4 slots, but the names match how the
slots are really used.  This is a purely mechanical renaming, but some
of the code makes a lot more sense now.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@144503 91177308-0d34-0410-b5e6-96231b3b80d8
2011-11-13 20:45:27 +00:00
Jakob Stoklund Olesen
573a32d487 Leave hasPHIKill flags alone in LiveInterval::RenumberValues.
It is conservatively correct to keep the hasPHIKill flags, even after
deleting PHI-defs.

The calculation can be very expensive after taildup has created a
quadratic number of indirectbr edges in the CFG, and the hasPHIKill flag
isn't used for anything after RenumberValues().

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@139780 91177308-0d34-0410-b5e6-96231b3b80d8
2011-09-15 04:37:18 +00:00
Jakob Stoklund Olesen
ee5655dca4 Switch extendInBlock() to take a kill slot instead of the last use slot.
Three out of four clients prefer this interface which is consistent with
extendIntervalEndTo() and LiveRangeCalc::extend().

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@139604 91177308-0d34-0410-b5e6-96231b3b80d8
2011-09-13 16:47:56 +00:00
Jakob Stoklund Olesen
d2eff137ca Replace a broken LiveInterval::MergeValueInAsValue() with something simpler.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@127960 91177308-0d34-0410-b5e6-96231b3b80d8
2011-03-19 23:02:49 +00:00
Jakob Stoklund Olesen
2254227791 Rewrite instructions as part of ConnectedVNInfoEqClasses::Distribute.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@127779 91177308-0d34-0410-b5e6-96231b3b80d8
2011-03-17 00:23:45 +00:00
Jakob Stoklund Olesen
55768d763d That's it, I am declaring this a failure of the C++03 STL.
There are too many compatibility problems with using mixed types in
std::upper_bound, and I don't want to spend 110 lines of boilerplate setting up
a call to a 10-line function. Binary search is not /that/ hard to implement
correctly.

I tried terminating the binary search with a linear search, but that actually
made the algorithm slower against my expectation. Most live intervals have less
than 4 segments. The early test against endIndex() does pay, and this version is
25% faster than plain std::upper_bound().

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@127522 91177308-0d34-0410-b5e6-96231b3b80d8
2011-03-12 01:50:35 +00:00
John Wiegley
6fd2472b1b Fix use of CompEnd predicate to be standards conforming
The existing CompEnd predicate does not define a strict weak order as required
by the C++03 standard; therefore, its use as a predicate to std::upper_bound
is invalid. For a discussion of this issue, see
http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#270

This patch replaces the asymmetrical comparison with an iterator adaptor that
achieves the same effect while being strictly standard-conforming by ensuring
an apples-to-apples comparison.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@127462 91177308-0d34-0410-b5e6-96231b3b80d8
2011-03-11 08:54:34 +00:00
Jakob Stoklund Olesen
5bf76cd119 Fix the build for MSVC 9 whose upper_bound() wants to compare elements in the sorted array.
Patch by Olaf Krzikalla!

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@127264 91177308-0d34-0410-b5e6-96231b3b80d8
2011-03-08 19:37:54 +00:00
Oscar Fuentes
3aefa7771d Revert "Make a comparator's argument `const'. This fixes the build for
MSVC 9."

The "fix" was meaningless.

This reverts commit r127245.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@127260 91177308-0d34-0410-b5e6-96231b3b80d8
2011-03-08 19:26:21 +00:00
Oscar Fuentes
86e4eeb6c7 Make a comparator's argument `const'. This fixes the build for MSVC 9.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@127245 91177308-0d34-0410-b5e6-96231b3b80d8
2011-03-08 13:52:07 +00:00
Jakob Stoklund Olesen
b64f669b66 Avoid comparing invalid slot indexes.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@126922 91177308-0d34-0410-b5e6-96231b3b80d8
2011-03-03 04:23:52 +00:00
Jakob Stoklund Olesen
9763e2bf39 Move LiveIntervalMap::extendTo into LiveInterval itself.
This method could probably be used by LiveIntervalAnalysis::shrinkToUses, and
now it can use extendIntervalEndTo() which coalesces ranges.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@126803 91177308-0d34-0410-b5e6-96231b3b80d8
2011-03-02 00:06:15 +00:00
Jakob Stoklund Olesen
ccdb3fcef9 Implement RAGreedy::splitAroundRegion and remove loop splitting.
Region splitting includes loop splitting as a subset, and it is more generic.
The splitting heuristics for variables that are live in more than one block are
now:

1. Try to create a region that covers multiple basic blocks.
2. Try to create a new live range for each block with multiple uses.
3. Spill.

Steps 2 and 3 are similar to what the standard spiller is doing.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@123853 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-19 22:11:48 +00:00
Jakob Stoklund Olesen
be97e906e0 Teach TargetRegisterInfo how to cram stack slot indexes in with the virtual and
physical register numbers.

This makes the hack used in LiveInterval official, and lets LiveInterval be
oblivious of stack slots.

The isPhysicalRegister() and isVirtualRegister() predicates don't know about
this, so when a variable may contain a stack slot, isStackSlot() should always
be tested first.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@123128 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-09 21:17:37 +00:00
Jakob Stoklund Olesen
4314268128 Replace TargetRegisterInfo::printReg with a PrintReg class that also works without a TRI instance.
Print virtual registers numbered from 0 instead of the arbitrary
FirstVirtualRegister. The first virtual register is printed as %vreg0.
TRI::NoRegister is printed as %noreg.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@123107 91177308-0d34-0410-b5e6-96231b3b80d8
2011-01-09 03:05:53 +00:00
Jakob Stoklund Olesen
b907e8a2d4 Use IntEqClasses to compute connected components of live intervals.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@122296 91177308-0d34-0410-b5e6-96231b3b80d8
2010-12-21 00:48:17 +00:00
Cameron Zwarich
fb69f6037d Fix PR8815 by checking for an explicit clobber def tied to a use operand in
ConnectedVNInfoEqClasses::Classify().


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@122202 91177308-0d34-0410-b5e6-96231b3b80d8
2010-12-19 22:12:45 +00:00
Jakob Stoklund Olesen
6d309059a7 Teach ConnectedVNInfoEqClasses::Classify to deal with unused values.
We don't want unused values forming their own equivalence classes, so we lump
them all together in one class, and then merge them with the class of the last
used value.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@117670 91177308-0d34-0410-b5e6-96231b3b80d8
2010-10-29 17:37:29 +00:00
Jakob Stoklund Olesen
eeaae20be0 Fix broken equivalence class calculation. We could probably also use
EquvivalenceClasses.h except it looks like overkill when elements are continuous
integers.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@117631 91177308-0d34-0410-b5e6-96231b3b80d8
2010-10-29 00:40:59 +00:00
Benjamin Kramer
ccefe32141 Silence compiler warning.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@116156 91177308-0d34-0410-b5e6-96231b3b80d8
2010-10-09 16:36:44 +00:00
Jakob Stoklund Olesen
54f32e6575 Classify value numbers into connected components in linear time.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@116105 91177308-0d34-0410-b5e6-96231b3b80d8
2010-10-08 21:19:28 +00:00
Jakob Stoklund Olesen
0253df9a89 After splitting, the remaining LiveInterval may be fragmented into multiple
connected components. These components should be allocated different virtual
registers because there is no reason for them to be allocated together.

Add the ConnectedVNInfoEqClasses class to calculate the connected components,
and move values to new LiveIntervals.

Use it from SplitKit::rewrite by creating new virtual registers for the
components.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@116006 91177308-0d34-0410-b5e6-96231b3b80d8
2010-10-07 23:34:34 +00:00
Jakob Stoklund Olesen
a818c072af Tweak VNInfo printing.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@115650 91177308-0d34-0410-b5e6-96231b3b80d8
2010-10-05 18:48:57 +00:00
Jakob Stoklund Olesen
201ecfca98 Add assert for valid slot indexes.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@115649 91177308-0d34-0410-b5e6-96231b3b80d8
2010-10-05 18:48:55 +00:00
Jakob Stoklund Olesen
e0a73ec0a9 When RemoveCopyByCommutingDef is creating additional identity copies, just use
LiveInterval::MergeValueNumberInto instead of trying to extend LiveRanges and
getting it wrong.

This fixed PR8249 where a valno with a multi-segment live range was defined by
an identity copy created by RemoveCopyByCommutingDef. Some of the live
segments disappeared.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@115385 91177308-0d34-0410-b5e6-96231b3b80d8
2010-10-01 23:52:25 +00:00
Lang Hames
6e2968c85c Removed VNInfo::isDefAccurate(). Def "accuracy" can be checked by testing whether LiveIntervals::getInstructionFromIndex(def) returns NULL.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@114791 91177308-0d34-0410-b5e6-96231b3b80d8
2010-09-25 12:04:16 +00:00
Jakob Stoklund Olesen
7c72707216 Refix MSVC9 and upper_bound. It actually needs a fully symmetric comparator.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@114469 91177308-0d34-0410-b5e6-96231b3b80d8
2010-09-21 20:16:12 +00:00
Jakob Stoklund Olesen
89bfef003e Don't pollute the global namespace.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@114459 91177308-0d34-0410-b5e6-96231b3b80d8
2010-09-21 18:34:17 +00:00