Commit Graph

43 Commits

Author SHA1 Message Date
Matt Arsenault 5fbc87021e RA: Replace asserts related to empty live intervals
These don't exactly assert the same thing anymore, and
allow empty live intervals with non-empty uses.

Removed in r308808 and r308813.

llvm-svn: 308906
2017-07-24 18:07:55 +00:00
Matt Arsenault 6a963f76ca RA: Remove assert on empty live intervals
This is possible if there is an undef use when
splitting the vreg during spilling.

Fixes bug 33620.

llvm-svn: 308808
2017-07-21 23:56:13 +00:00
Chandler Carruth 6bda14b313 Sort the remaining #include lines in include/... and lib/....
I did this a long time ago with a janky python script, but now
clang-format has built-in support for this. I fed clang-format every
line with a #include and let it re-sort things according to the precise
LLVM rules for include ordering baked into clang-format these days.

I've reverted a number of files where the results of sorting includes
isn't healthy. Either places where we have legacy code relying on
particular include ordering (where possible, I'll fix these separately)
or where we have particular formatting around #include lines that
I didn't want to disturb in this patch.

This patch is *entirely* mechanical. If you get merge conflicts or
anything, just ignore the changes in this patch and run clang-format
over your #include lines in the files.

Sorry for any noise here, but it is important to keep these things
stable. I was seeing an increasing number of patches with irrelevant
re-ordering of #include lines because clang-format was used. This patch
at least isolates that churn, makes it easy to skip when resolving
conflicts, and gets us to a clean baseline (again).

llvm-svn: 304787
2017-06-06 11:49:48 +00:00
Matthias Braun 9f15a79e5d Timer: Track name and description.
The previously used "names" are rather descriptions (they use multiple
words and contain spaces), use short programming language identifier
like strings for the "names" which should be used when exporting to
machine parseable formats.

Also removed a unused TimerGroup from Hexxagon.

Differential Revision: https://reviews.llvm.org/D25583

llvm-svn: 287369
2016-11-18 19:43:18 +00:00
Krzysztof Parzyszek a7ed090bba Create subranges for new intervals resulting from live interval splitting
The register allocator can split a live interval of a register into a set
of smaller intervals. After the allocation of registers is complete, the
rewriter will modify the IR to replace virtual registers with the corres-
ponding physical registers. At this stage, if a register corresponding
to a subregister of a virtual register is used, the rewriter will check
if that subregister is undefined, and if so, it will add the <undef> flag
to the machine operand. The function verifying liveness of the subregis-
ter would assume that it is undefined, unless any of the subranges of the
live interval proves otherwise.
The problem is that the live intervals created during splitting do not
have any subranges, even if the original parent interval did. This could
result in the <undef> flag placed on a register that is actually defined.

Differential Revision: http://reviews.llvm.org/D21189

llvm-svn: 279625
2016-08-24 13:37:55 +00:00
Mehdi Amini b550cb1750 [NFC] Header cleanup
Removed some unused headers, replaced some headers with forward class declarations.

Found using simple scripts like this one:
clear && ack --cpp -l '#include "llvm/ADT/IndexedMap.h"' | xargs grep -L 'IndexedMap[<]' | xargs grep -n --color=auto 'IndexedMap'

Patch by Eugene Kosov <claprix@yandex.ru>

Differential Revision: http://reviews.llvm.org/D19219

From: Mehdi Amini <mehdi.amini@apple.com>
llvm-svn: 266595
2016-04-18 09:17:29 +00:00
Wei Mi 9a16d655c7 Recommit r265547, and r265610,r265639,r265657 on top of it, plus
two fixes with one about error verify-regalloc reported, and
another about live range update of phi after rematerialization.

r265547:
Replace analyzeSiblingValues with new algorithm to fix its compile
time issue. The patch is to solve PR17409 and its duplicates.

analyzeSiblingValues is a N x N complexity algorithm where N is
the number of siblings generated by reg splitting. Although it
causes siginificant compile time issue when N is large, it is also
important for performance since it removes redundent spills and
enables rematerialization.

To solve the compile time issue, the patch removes analyzeSiblingValues
and replaces it with lower cost alternatives containing two parts. The
first part creates a new spill hoisting method in postOptimization of
register allocation. It does spill hoisting at once after all the spills
are generated instead of inside every instance of selectOrSplit. The
second part queries the define expr of the original register for
rematerializaiton and keep it always available during register allocation
even if it is already dead. It deletes those dead instructions only in
postOptimization. With the two parts in the patch, it can remove
analyzeSiblingValues without sacrificing performance.

Patches on top of r265547:
r265610 "Fix the compare-clang diff error introduced by r265547."
r265639 "Fix the sanitizer bootstrap error in r265547."
r265657 "InlineSpiller.cpp: Escap \@ in r265547. [-Wdocumentation]"

Differential Revision: http://reviews.llvm.org/D15302
Differential Revision: http://reviews.llvm.org/D18934
Differential Revision: http://reviews.llvm.org/D18935
Differential Revision: http://reviews.llvm.org/D18936

llvm-svn: 266162
2016-04-13 03:08:27 +00:00
Hans Wennborg 5a7723c7a2 Revert r265547 "Recommit r265309 after fixed an invalid memory reference bug happened"
It caused PR27275: "ARM: Bad machine code: Using an undefined physical register"

Also reverting the following commits that were landed on top:
r265610 "Fix the compare-clang diff error introduced by r265547."
r265639 "Fix the sanitizer bootstrap error in r265547."
r265657 "InlineSpiller.cpp: Escap \@ in r265547. [-Wdocumentation]"

llvm-svn: 265790
2016-04-08 15:17:43 +00:00
Wei Mi 18293bef4e Recommit r265309 after fixed an invalid memory reference bug happened
when DenseMap growed and moved memory. I verified it fixed the bootstrap
problem on x86_64-linux-gnu but I cannot verify whether it fixes
the bootstrap error on clang-ppc64be-linux. I will watch the build-bot
result closely.

Replace analyzeSiblingValues with new algorithm to fix its compile
time issue. The patch is to solve PR17409 and its duplicates.

analyzeSiblingValues is a N x N complexity algorithm where N is
the number of siblings generated by reg splitting. Although it
causes siginificant compile time issue when N is large, it is also
important for performance since it removes redundent spills and
enables rematerialization.

To solve the compile time issue, the patch removes analyzeSiblingValues
and replaces it with lower cost alternatives containing two parts. The
first part creates a new spill hoisting method in postOptimization of
register allocation. It does spill hoisting at once after all the spills
are generated instead of inside every instance of selectOrSplit. The
second part queries the define expr of the original register for
rematerializaiton and keep it always available during register allocation
even if it is already dead. It deletes those dead instructions only in
postOptimization. With the two parts in the patch, it can remove
analyzeSiblingValues without sacrificing performance.

Differential Revision: http://reviews.llvm.org/D15302

llvm-svn: 265547
2016-04-06 15:41:07 +00:00
Wei Mi fb5252cac1 Revert r265309 and r265312 because they caused some errors I need to investigate.
llvm-svn: 265317
2016-04-04 17:45:03 +00:00
Wei Mi ffbc9c7f3b Replace analyzeSiblingValues with new algorithm to fix its compile
time issue. The patch is to solve PR17409 and its duplicates.

analyzeSiblingValues is a N x N complexity algorithm where N is
the number of siblings generated by reg splitting. Although it
causes siginificant compile time issue when N is large, it is also
important for performance since it removes redundent spills and
enables rematerialization.

To solve the compile time issue, the patch removes analyzeSiblingValues
and replaces it with lower cost alternatives containing two parts. The
first part creates a new spill hoisting method in postOptimization of
register allocation. It does spill hoisting at once after all the spills
are generated instead of inside every instance of selectOrSplit. The
second part queries the define expr of the original register for
rematerializaiton and keep it always available during register allocation
even if it is already dead. It deletes those dead instructions only in
postOptimization. With the two parts in the patch, it can remove
analyzeSiblingValues without sacrificing performance.

Differential Revision: http://reviews.llvm.org/D15302

llvm-svn: 265309
2016-04-04 16:42:40 +00:00
Benjamin Kramer 799003bf8c Re-sort includes with sort-includes.py and insert raw_ostream.h where it's used.
llvm-svn: 232998
2015-03-23 19:32:43 +00:00
Quentin Colombet a799e2e014 [RegAllocGreedy] Introduce a late pass to repair broken hints.
A broken hint is a copy where both ends are assigned different colors. When a
variable gets evicted in the neighborhood of such copies, it is likely we can
reconcile some of them.


** Context **

Copies are inserted during the register allocation via splitting. These split
points are required to relax the constraints on the allocation problem. When
such a point is inserted, both ends of the copy would not share the same color
with respect to the current allocation problem. When variables get evicted,
the allocation problem becomes different and some split point may not be
required anymore. However, the related variables may already have been colored.

This usually shows up in the assembly with pattern like this:
def A
...
save A to B
def A
use A
restore A from B
...
use B

Whereas we could simply have done:
def B
...
def A
use A
...
use B


** Proposed Solution **

A variable having a broken hint is marked for late recoloring if and only if
selecting a register for it evict another variable. Indeed, if no eviction
happens this is pointless to look for recoloring opportunities as it means the
situation was the same as the initial allocation problem where we had to break
the hint.

Finally, when everything has been allocated, we look for recoloring
opportunities for all the identified candidates.
The recoloring is performed very late to rely on accurate copy cost (all
involved variables are allocated).
The recoloring is simple unlike the last change recoloring. It propagates the
color of the broken hint to all its copy-related variables. If the color is
available for them, the recoloring uses it, otherwise it gives up on that hint
even if a more complex coloring would have worked.

The recoloring happens only if it is profitable. The profitability is evaluated
using the expected frequency of the copies of the currently recolored variable
with a) its current color and b) with the target color. If a) is greater or
equal than b), then it is profitable and the recoloring happen.


** Example **

Consider the following example:
BB1:
  a =
  b =
BB2:
  ...
   = b
   = a
Let us assume b gets split:
BB1:
  a =
  b =
BB2:
  c = b
  ...
  d = c
  = d
  = a
Because of how the allocation work, b, c, and d may be assigned different
colors. Now, if a gets evicted to make room for c, assuming b and d were
assigned to something different than a.
We end up with:
BB1:
  a =
  st a, SpillSlot
  b =
BB2:
  c = b
  ...
  d = c
  = d
  e = ld SpillSlot
  = e
This is likely that we can assign the same register for b, c, and d,
getting rid of 2 copies.


** Performances **

Both ARM64 and x86_64 show performance improvements of up to 3% for the
llvm-testsuite + externals with Os and O3. There are a few regressions too that
comes from the (in)accuracy of the block frequency estimate.

<rdar://problem/18312047>

llvm-svn: 225422
2015-01-08 01:16:39 +00:00
Craig Topper cf0444ba2a Move register class name strings to a single array in MCRegisterInfo to reduce static table size and number of relocation entries.
Indices into the table are stored in each MCRegisterClass instead of a pointer. A new method, getRegClassName, is added to MCRegisterInfo and TargetRegisterInfo to lookup the string in the table.

llvm-svn: 222118
2014-11-17 05:50:14 +00:00
Eric Christopher 307c2cb26f Remove unnecessary TargetMachine.h includes.
llvm-svn: 219672
2014-10-14 07:22:08 +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 abb90c9ddb Phase 1 of refactoring the MachineRegisterInfo iterators to make them suitable
for use with C++11 range-based for-loops.

The gist of phase 1 is to remove the skipInstruction() and skipBundle()
methods from these iterators, instead splitting each iterator into a version
that walks operands, a version that walks instructions, and a version that
walks bundles.  This has the result of making some "clever" loops in lib/CodeGen
more verbose, but also makes their iterator invalidation characteristics much
more obvious to the casual reader. (Making them concise again in the future is a
good motivating case for a pre-incrementing range adapter!)

Phase 2 of this undertaking with consist of removing the getOperand() method,
and changing operator*() of the operand-walker to return a MachineOperand&.  At
that point, it should be possible to add range views for them that work as one
might expect.

llvm-svn: 203757
2014-03-13 06:02:25 +00:00
Manman Ren 28671403bf Fix typo
llvm-svn: 201944
2014-02-22 19:31:28 +00:00
Andrew Trick 059e800fda DEBUG shouldEvict decisions
llvm-svn: 195490
2013-11-22 19:07:42 +00:00
Juergen Ributzka d12ccbd343 [weak vtables] Remove a bunch of weak vtables
This patch removes most of the trivial cases of weak vtables by pinning them to
a single object file. The memory leaks in this version have been fixed. Thanks
Alexey for pointing them out.

Differential Revision: http://llvm-reviews.chandlerc.com/D2068

Reviewed by Andy

llvm-svn: 195064
2013-11-19 00:57:56 +00:00
Alexey Samsonov 49109a279c Revert r194865 and r194874.
This change is incorrect. If you delete virtual destructor of both a base class
and a subclass, then the following code:
  Base *foo = new Child();
  delete foo;
will not cause the destructor for members of Child class. As a result, I observe
plently of memory leaks. Notable examples I investigated are:
ObjectBuffer and ObjectBufferStream, AttributeImpl and StringSAttributeImpl.

llvm-svn: 194997
2013-11-18 09:31:53 +00:00
Juergen Ributzka dbedae89b9 [weak vtables] Remove a bunch of weak vtables
This patch removes most of the trivial cases of weak vtables by pinning them to
a single object file.

Differential Revision: http://llvm-reviews.chandlerc.com/D2068

Reviewed by Andy

llvm-svn: 194865
2013-11-15 22:34:48 +00:00
Matthias Braun f6fe6bfffe Print register in LiveInterval::print()
llvm-svn: 192398
2013-10-10 21:29:05 +00:00
Benjamin Kramer 7200a46c17 Emit a better error when running out of registers on inline asm.
The most likely case where this error happens is when the user specifies
too many register operands. Don't make it look like an internal LLVM bug
when we can see that the error is coming from an inline asm instruction.
For other instructions we keep the "ran out of registers" error.

llvm-svn: 192041
2013-10-05 19:33:37 +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
Craig Topper 9fdc70e846 Make constant string pointer into an array to remove a pointer lookup for every access.
llvm-svn: 186482
2013-07-17 03:11:32 +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
Chad Rosier ed119d542b Revert r168630, r168631, and r168633 as these are causing nightly test failures.
llvm-svn: 168751
2012-11-28 00:21:29 +00:00
Chad Rosier a44e1825a3 Now that the X86 Maximal Stack Alignment Check pass has been removed (i.e.,
r168627), we no longer need to call the freezeReservedRegs() function a second
time.  Previously, this pass was conservatively adding the FP to the set of
reserved registers, requiring the second update to the reserved registers.
rdar://12719844

llvm-svn: 168630
2012-11-26 23:14:37 +00:00
Jakob Stoklund Olesen 2d2dec96e0 Remove LiveIntervalUnions from RegAllocBase.
They are living in LiveRegMatrix now.

llvm-svn: 158868
2012-06-20 22:52:29 +00:00
Jakob Stoklund Olesen 03b87d5aaa Convert RABasic to using LiveRegMatrix interference checking.
Stop using the LiveIntervalUnions provided by RegAllocBase, they will be
removed soon.

llvm-svn: 158866
2012-06-20 22:52:24 +00:00
Jakob Stoklund Olesen a1f43dcdb8 Avoid iterating with LiveIntervals::iterator.
That is a DenseMap iterator keyed by pointers, so the iteration order is
nondeterministic.

I would like to replace the DenseMap with an IndexedMap which doesn't
allow iteration.

llvm-svn: 158856
2012-06-20 21:25:05 +00:00
Jakob Stoklund Olesen be336295cd Also compute MBB live-in lists in the new rewriter pass.
This deduplicates some code from the optimizing register allocators, and
it means that it is now possible to change the register allocators'
solutions simply by editing the VirtRegMap between the register
allocator pass and the rewriter.

llvm-svn: 158249
2012-06-09 00:14:47 +00:00
Jakob Stoklund Olesen c141ba584e Move LiveUnionArray into LiveIntervalUnion.h
It is useful outside RegAllocBase.

llvm-svn: 158041
2012-06-05 23:57:30 +00:00
Jakob Stoklund Olesen 46d229c573 Don't print register names in LiveIntervalUnion::print().
Soon we'll be making LiveIntervalUnions for register units as well.

This was the only place using the RepReg member, so just remove it.

llvm-svn: 158038
2012-06-05 23:07:19 +00:00
Jakob Stoklund Olesen f3f7d6f6e2 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.

llvm-svn: 158031
2012-06-05 22:51:54 +00:00
Jakob Stoklund Olesen 54038d796c Switch all register list clients to the new MC*Iterator interface.
No functional change intended.

Sorry for the churn. The iterator classes are supposed to help avoid
giant commits like this one in the future. The TableGen-produced
register lists are getting quite large, and it may be necessary to
change the table representation.

This makes it possible to do so without changing all clients (again).

llvm-svn: 157854
2012-06-01 23:28:30 +00:00
Jakob Stoklund Olesen 165473247f Don't look for empty live ranges in the unions.
Empty live ranges represent undef and still get allocated, but they
won't appear in LiveIntervalUnions.

Patch by Patrik Hägglund!

llvm-svn: 156685
2012-05-12 00:33:28 +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
Craig Topper 1d32658877 Use uint16_t to store register overlaps to reduce static data.
llvm-svn: 152001
2012-03-04 10:43:23 +00:00
Jakob Stoklund Olesen 73edbf1682 Sink spillInterferences into RABasic.
This helper method is too simplistic for RAGreedy.

llvm-svn: 147976
2012-01-11 22:52:14 +00:00
Jakob Stoklund Olesen a818d804a1 Move RegAllocBase into its own cpp file separate from RABasic.
No functional change.

llvm-svn: 147972
2012-01-11 22:28:30 +00:00