Commit Graph

71 Commits

Author SHA1 Message Date
Jiangning Liu c3053129b9 Add TargetInstrInfo interface isAsCheapAsAMove.
llvm-svn: 214158
2014-07-29 01:55:19 +00:00
Chandler Carruth 1b9dde087e [Modules] Remove potential ODR violations by sinking the DEBUG_TYPE
define below all header includes in the lib/CodeGen/... tree. While the
current modules implementation doesn't check for this kind of ODR
violation yet, it is likely to grow support for it in the future. It
also removes one layer of macro pollution across all the included
headers.

Other sub-trees will follow.

llvm-svn: 206837
2014-04-22 02:02:50 +00:00
Craig Topper c0196b1b40 [C++11] More 'nullptr' conversion. In some cases just using a boolean check instead of comparing to nullptr.
llvm-svn: 206142
2014-04-14 00:51:57 +00:00
Owen Anderson b36376efcb Switch a number of loops in lib/CodeGen over to range-based for-loops, now that
the MachineRegisterInfo iterators are compatible with it.

llvm-svn: 204075
2014-03-17 19:36:09 +00:00
Owen Anderson 16c6bf49b7 Phase 2 of the great MachineRegisterInfo cleanup. This time, we're changing
operator* on the by-operand iterators to return a MachineOperand& rather than
a MachineInstr&.  At this point they almost behave like normal iterators!

Again, this requires making some existing loops more verbose, but should pave
the way for the big range-based for-loop cleanups in the future.

llvm-svn: 203865
2014-03-13 23:12:04 +00:00
Arnaud A. de Grandmaison ea3ac1612c CalcSpillWeights: give a better describing name to calculateSpillWeights
Besides, this relates it more obviously to the VirtRegAuxInfo::calculateSpillWeightAndHint.

No functionnal change.

llvm-svn: 194404
2013-11-11 19:04:45 +00:00
Matthias Braun 34e1be9451 Represent RegUnit liveness with LiveRange instance
Previously LiveInterval has been used, but having a spill weight and
register number is unnecessary for a register unit.

llvm-svn: 192397
2013-10-10 21:29:02 +00:00
Matthias Braun 88dd0abd2d Pass LiveQueryResult by value
This makes the API a bit more natural to use and makes it easier to make
LiveRanges implementation details private.

llvm-svn: 192394
2013-10-10 21:28:52 +00:00
Andrew Trick 3bf33075ce Use LiveRangeQuery for instruction-level liveness queries.
Remove redundant or bug-prone LiveInterval APIs.

llvm-svn: 189685
2013-08-30 17:58:49 +00:00
Andrew Trick ff60477306 Replace LiveInterval::killedAt with isKilledAtInstr.
Return true for LRGs that end at EarlyClobber or Register slots.

llvm-svn: 189642
2013-08-30 04:31:01 +00:00
Mark Lacey 9d8103de7a Auto-compute live intervals on demand.
When new virtual registers are created during splitting/spilling, defer
creation of the live interval until we need to use the live interval.

Along with the recent commits to notify LiveRangeEdit when new virtual
registers are created, this makes it possible for functions like
TargetInstrInfo::loadRegFromStackSlot() and
TargetInstrInfo::storeRegToStackSlot() to create multiple virtual
registers as part of the process of generating loads/stores for
different register classes, and then have the live intervals for those
new registers computed when they are needed.

llvm-svn: 188437
2013-08-14 23:50:16 +00:00
Mark Lacey f367cd9239 Notify LiveRangeEdit of new virtual registers.
Add a delegate class to MachineRegisterInfo with a single virtual
function, MRI_NoteNewVirtualRegister(). Update LiveRangeEdit to inherit
from this delegate class and override the definition of the callback
with an implementation that tracks the newly created virtual registers.

llvm-svn: 188435
2013-08-14 23:50:09 +00:00
Mark Lacey f9ea88546f Track new virtual registers by register number.
Track new virtual registers by register number, rather than by the live
interval created for them. This is the first step in separating the
creation of new virtual registers and new live intervals.  Eventually
live intervals will be created and populated on demand after the virtual
registers have been created and used in instructions.

llvm-svn: 188434
2013-08-14 23:50:04 +00:00
Jakob Stoklund Olesen 4417c7b265 Remove unnecessary parameter to RenumberValues.
Patch by Matthias Braun!

llvm-svn: 188393
2013-08-14 17:28:52 +00:00
Andrew Trick cbd7305d09 Prevent LiveRangeEdit from deleting bundled instructions.
We have no targets on trunk that bundle before regalloc. However, we
have been advertising regalloc as bundle safe for use with out-of-tree
targets. We need to at least contain the parts of the code that are
still unsafe.

llvm-svn: 184620
2013-06-22 00:33:48 +00:00
Andrew Trick 6b9c49a275 Handle more cases in LiveRangeEdit::eliminateDeadDefs.
Live intervals for dead physregs may be created during coalescing. We
need to update these in the event that their instruction goes away.

crash.ll is the unit test that catches it when MI sched is enabled on
X86.

llvm-svn: 184572
2013-06-21 18:33:20 +00:00
Andrew Trick 530fc1f486 Refactor LiveRangeEdit::eliminateDeadDefs.
I want to add logic to handle more cases.

llvm-svn: 184571
2013-06-21 18:33:17 +00:00
Andrew Trick 7df3f01703 whitespace
llvm-svn: 184570
2013-06-21 18:33:14 +00:00
Benjamin Kramer e2a1d89e14 Switch spill weights from a basic loop depth estimation to BlockFrequencyInfo.
The main advantages here are way better heuristics, taking into account not
just loop depth but also __builtin_expect and other static heuristics and will
eventually learn how to use profile info. Most of the work in this patch is
pushing the MachineBlockFrequencyInfo analysis into the right places.

This is good for a 5% speedup on zlib's deflate (x86_64), there were some very
unfortunate spilling decisions in its hottest loop in longest_match(). Other
benchmarks I tried were mostly neutral.

This changes register allocation in subtle ways, update the tests for it.
2012-02-20-MachineCPBug.ll was deleted as it's very fragile and the instruction
it looked for was gone already (but the FileCheck pattern picked up unrelated
stuff).

llvm-svn: 184105
2013-06-17 19:00:36 +00:00
Jakub Staszak 26ac8a7b16 Add some constantness.
llvm-svn: 177356
2013-03-18 23:40:46 +00:00
Chandler Carruth ed0881b2a6 Use the new script to sort the includes of every file under lib.
Sooooo many of these had incorrect or strange main module includes.
I have manually inspected all of these, and fixed the main module
include to be the nearest plausible thing I could find. If you own or
care about any of these source files, I encourage you to take some time
and check that these edits were sensible. I can't have broken anything
(I strictly added headers, and reordered them, never removed), but they
may not be the headers you'd really like to identify as containing the
API being implemented.

Many forward declarations and missing includes were added to a header
files to allow them to parse cleanly when included first. The main
module rule does in fact have its merits. =]

llvm-svn: 169131
2012-12-03 16:50:05 +00:00
Jakob Stoklund Olesen 26c9d70d28 Make the LiveRegMatrix analysis available to targets.
No functional change, just moved header files.

Targets can inject custom passes between register allocation and
rewriting. This makes it possible to tweak the register allocation
before rewriting, using the full global interference checking available
from LiveRegMatrix.

llvm-svn: 168806
2012-11-28 19:13:06 +00:00
Jakob Stoklund Olesen 4df59a9ff8 Avoid rematerializing a redef immediately after the old def.
PR14098 contains an example where we would rematerialize a MOV8ri
immediately after the original instruction:

  %vreg7:sub_8bit<def> = MOV8ri 9; GR32_ABCD:%vreg7
  %vreg22:sub_8bit<def> = MOV8ri 9; GR32_ABCD:%vreg7

Besides being pointless, it is also wrong since the original instruction
only redefines part of the register, and the value read by the new
instruction is wrong.

The problem was the LiveRangeEdit::allUsesAvailableAt() didn't
special-case OrigIdx == UseIdx and found the wrong SSA value.

llvm-svn: 166068
2012-10-16 22:51:58 +00:00
Jakob Stoklund Olesen cea596acf7 Remove LIS::isAllocatable() and isReserved() helpers.
All callers can simply use the corresponding MRI functions.

llvm-svn: 165985
2012-10-15 22:14:34 +00:00
Jakob Stoklund Olesen 1d19582a8f Avoid dereferencing a NULL pointer.
Fixes PR13943.

llvm-svn: 164778
2012-09-27 16:34:19 +00:00
Jakob Stoklund Olesen 374071dde2 Avoid creating dangling physreg live ranges during DCE.
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
2012-08-02 16:36:47 +00:00
Jakob Stoklund Olesen e2cfd0d45a Avoid folding loads that are unsafe to move.
LiveRangeEdit::foldAsLoad() can eliminate a register by folding a load
into its only use. Only do that when the load is safe to move, and it
won't extend any live ranges.

This fixes PR13414.

llvm-svn: 160575
2012-07-20 21:29:31 +00:00
Jakob Stoklund Olesen 7809578cfe Use MRI::isConstantPhysReg() to check remat feasibility.
Don't depend on LiveIntervals::hasInterval() to determine if a physreg
is reserved and constant.

llvm-svn: 159013
2012-06-22 17:31:01 +00:00
Jakob Stoklund Olesen 924279ca0e Only erase virtregs with no uses left.
Also make sure registers aren't erased twice if the dead def mentions
the register twice.

This fixes PR12911.

llvm-svn: 157254
2012-05-22 14:52:12 +00:00
Jakob Stoklund Olesen a34a69ce0c Fix 12892.
Dead code elimination during coalescing could cause a virtual register
to be split into connected components. The following rewriting would be
confused about the already joined copies present in the code, but
without a corresponding value number in the live range.

Erase all joined copies instantly when joining intervals such that the
MI and LiveInterval representations are always in sync.

llvm-svn: 157135
2012-05-19 23:34:59 +00:00
Jakob Stoklund Olesen e5bbe37950 Allow LiveRangeEdit to be created with a NULL parent.
The dead code elimination with callbacks is still useful.

llvm-svn: 157100
2012-05-19 05:25:46 +00:00
Jakob Stoklund Olesen 3834dae65d Modernize naming convention for class members.
No functional change.

llvm-svn: 157079
2012-05-18 22:10:15 +00:00
Pete Cooper b98934cf72 Removed one last bad continue statement meant to be removed in r153914.
llvm-svn: 153975
2012-04-03 22:18:49 +00:00
Pete Cooper 4f0dbb27d9 Fixes to r153903. Added missing explanation of behaviour when the VirtRegMap is NULL. Also changed it in this case to just avoid updating the map, but live ranges or intervals will still get updated and created
llvm-svn: 153914
2012-04-03 00:28:46 +00:00
Pete Cooper 3ca96f9950 Moved LiveRangeEdit.h so that it can be called from other parts of the backend, not just libCodeGen
llvm-svn: 153906
2012-04-02 22:44:18 +00:00
Pete Cooper 2bde2f42b1 Refactored the LiveRangeEdit interface so that MachineFunction, TargetInstrInfo, MachineRegisterInfo, LiveIntervals, and VirtRegMap are all passed into the constructor and stored as members instead of passed in to each method.
llvm-svn: 153903
2012-04-02 22:22:53 +00:00
Lang Hames 2fbad222e1 Kill off LiveRangeEdit::getNewVRegs and LiveRangeEdit::getUselessVRegs. These
methods are no longer needed now that LinearScan has gone away.

(Contains tweaks trivialSpillEverywhere to enable the removal of getNewVRegs).

llvm-svn: 151658
2012-02-28 22:07:24 +00:00
Jim Grosbach 905c952efa Tidy up.
llvm-svn: 150820
2012-02-17 17:35:10 +00:00
David Blaikie a379b18173 Unweaken vtables as per http://llvm.org/docs/CodingStandards.html#ll_virtual_anch
llvm-svn: 146960
2011-12-20 02:50:00 +00:00
Pete Cooper 76e4bc4e26 Fixed register allocator splitting a live range on a spilling variable.
If we create new intervals for a variable that is being spilled, then those new intervals are not guaranteed to also spill.  This means that anything reading from the original spilling value might not get the correct value if spills were missed.

Fixes <rdar://problem/10546864>

llvm-svn: 146428
2011-12-12 22:16:27 +00:00
Evan Cheng 7f8e563a69 Add bundle aware API for querying instruction properties and switch the code
generator to it. For non-bundle instructions, these behave exactly the same
as the MC layer API.

For properties like mayLoad / mayStore, look into the bundle and if any of the
bundled instructions has the property it would return true.
For properties like isPredicable, only return true if *all* of the bundled
instructions have the property.
For properties like canFoldAsLoad, isCompare, conservatively return false for
bundles.

llvm-svn: 146026
2011-12-07 07:15:52 +00:00
Jakob Stoklund Olesen 90b5e565b6 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.

llvm-svn: 144503
2011-11-13 20:45:27 +00:00
Jakob Stoklund Olesen da96006975 Move CalculateRegClass to MRI::recomputeRegClass.
This function doesn't have anything to do with spill weights, and MRI
already has functions for manipulating the register class of a virtual
register.

llvm-svn: 137123
2011-08-09 16:46:27 +00:00
Jakob Stoklund Olesen bbad3bceb7 Fix PR10277.
Remat during spilling triggers dead code elimination. If a phi-def
becomes unused, that may also cause live ranges to split into separate
connected components.

This type of splitting is different from normal live range splitting. In
particular, there may not be a common original interval.

When the split range is its own original, make sure that the new
siblings are also their own originals. The range being split cannot be
used as an original since it doesn't cover the new siblings.

llvm-svn: 134413
2011-07-05 15:38:41 +00:00
Jakob Stoklund Olesen c5a8c08dba Add some statistics to the splitting and spilling frameworks.
llvm-svn: 130931
2011-05-05 17:22:53 +00:00
Jakob Stoklund Olesen 7d4067936a Minimize the slot indexes spanned by register ranges created when splitting.
When an interfering live range ends at a dead slot index between two
instructions, make sure that the inserted copy instruction gets a slot index
after the dead ones. This makes it possible to avoid the interference.

Ideally, there shouldn't be interference ending at a deleted instruction, but
physical register coalescing can sometimes do that to sub-registers.

This fixes PR9823.

llvm-svn: 130687
2011-05-02 05:29:58 +00:00
Jakob Stoklund Olesen 86e53ced08 Add debug output for rematerializable instructions.
llvm-svn: 129883
2011-04-20 22:14:20 +00:00
Jakob Stoklund Olesen 871f70609a Remember to set flag.
llvm-svn: 129579
2011-04-15 17:24:46 +00:00
Jakob Stoklund Olesen 96d04c8e00 Don't shrink live ranges after dead code elimination unless it is going to help.
In particular, don't repeatedly recompute the PIC base live range after rematerialization.

llvm-svn: 129275
2011-04-11 15:00:39 +00:00
Jakob Stoklund Olesen 18fd84c79a When dead code elimination removes all but one use, try to fold the single def into the remaining use.
Rematerialization can leave single-use loads behind that we might as well fold whenever possible.

llvm-svn: 128918
2011-04-05 20:20:26 +00:00