Commit Graph

186 Commits

Author SHA1 Message Date
Jakob Stoklund Olesen
cf97036675 Also attempt trivial coalescing for live intervals that end in a copy.
The coalescer is supposed to clean these up, but when setting up parameters
for a function call, there may be copies to physregs. If the defining
instruction has been LICM'ed far away, the coalescer won't touch it.

The register allocation hint does not always work - when the register
allocator is backtracking, it clears the hints.

This patch is more conservative than r90502, and does not break
483.xalancbmk/i686. It still breaks the PowerPC bootstrap, so it is disabled
by default, and can be enabled with the -trivial-coalesce-ends option.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@91049 91177308-0d34-0410-b5e6-96231b3b80d8
2009-12-10 17:48:32 +00:00
Lang Hames
6194569d22 Added a new "splitting" spiller.
When a call is placed to spill an interval this spiller will first try to
break the interval up into its component values. Single value intervals and
intervals which have already been split (or are the result of previous splits)
are spilled by the default spiller.

Splitting intervals as described above may improve the performance of generated
code in some circumstances. This work is experimental however, and it still
miscompiles many benchmarks. It's not recommended for general use yet.




git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@90951 91177308-0d34-0410-b5e6-96231b3b80d8
2009-12-09 05:39:12 +00:00
Bill Wendling
dc492e0370 Temporarily revert r90502. It was causing the llvm-gcc bootstrap on PPC to fail.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@90653 91177308-0d34-0410-b5e6-96231b3b80d8
2009-12-05 07:30:23 +00:00
Jakob Stoklund Olesen
6b74e505be Also attempt trivial coalescing for live intervals that end in a copy.
The coalescer is supposed to clean these up, but when setting up parameters
for a function call, there may be copies to physregs. If the defining
instruction has been LICM'ed far away, the coalescer won't touch it.

The register allocation hint does not always work - when the register
allocator is backtracking, it clears the hints.

This patch takes care of a few more cases that r90163 missed.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@90502 91177308-0d34-0410-b5e6-96231b3b80d8
2009-12-04 00:16:04 +00:00
Jakob Stoklund Olesen
1e78aa445c Remove the -early-coalescing option
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@89240 91177308-0d34-0410-b5e6-96231b3b80d8
2009-11-18 20:36:47 +00:00
Lang Hames
b3661585c0 Added an API to the SlotIndexes pass to allow new instructions to be inserted into the numbering.
PreAllocSplitting is now using this API to insert code.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@88725 91177308-0d34-0410-b5e6-96231b3b80d8
2009-11-14 00:02:51 +00:00
Jakob Stoklund Olesen
3de23e6f6c Fix inverted conflict test in -early-coalesce.
A non-identity copy cannot be coalesced when the phi join destination register
is live at the copy site.

Also verify the condition that the PHI join source register is only used in
the PHI join. Otherwise the coalescing is invalid.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@86322 91177308-0d34-0410-b5e6-96231b3b80d8
2009-11-07 01:58:40 +00:00
Lang Hames
233a60ec40 The Indexes Patch.
This introduces a new pass, SlotIndexes, which is responsible for numbering
instructions for register allocation (and other clients). SlotIndexes numbering
is designed to match the existing scheme, so this patch should not cause any
changes in the generated code.

For consistency, and to avoid naming confusion, LiveIndex has been renamed
SlotIndex.

The processImplicitDefs method of the LiveIntervals analysis has been moved
into its own pass so that it can be run prior to SlotIndexes. This was
necessary to match the existing numbering scheme.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@85979 91177308-0d34-0410-b5e6-96231b3b80d8
2009-11-03 23:52:08 +00:00
Evan Cheng
48bff92b60 Indentation.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@83607 91177308-0d34-0410-b5e6-96231b3b80d8
2009-10-09 00:57:38 +00:00
Lang Hames
cc3b0650f1 Renamed MachineInstrIndex to LiveIndex.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@83254 91177308-0d34-0410-b5e6-96231b3b80d8
2009-10-03 04:21:37 +00:00
Evan Cheng
db1c2c57ff Forgot this.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@81850 91177308-0d34-0410-b5e6-96231b3b80d8
2009-09-15 07:05:12 +00:00
Evan Cheng
752195e3c6 Add early coalescing to liveintervals. This is work in progress and is known to miscompute some tests. Read it at your own rish, I have aged 10 year while writing this.
The gist of this is if source of some of the copies that feed into a phi join is defined by the phi join, we'd like to eliminate them. However, if any of the non-identity source overlaps the live interval of the phi join then the coalescer won't be able to coalesce them. The early coalescer's job is to eliminate the identity copies by partially-coalescing the two live intervals.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@81796 91177308-0d34-0410-b5e6-96231b3b80d8
2009-09-14 21:33:42 +00:00
Lang Hames
4a39ba9926 Whoops. Committed the headers for r81605 - 'Moved some more index operations over to LiveIntervals.'
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@81609 91177308-0d34-0410-b5e6-96231b3b80d8
2009-09-12 04:54:18 +00:00
Lang Hames
9647994e09 Removed static qualifier from a few index related methods. These methods may require a LiveIntervals instance in future.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@81374 91177308-0d34-0410-b5e6-96231b3b80d8
2009-09-09 20:14:17 +00:00
Lang Hames
8651125d28 Replaces uses of unsigned for indexes in LiveInterval and VNInfo with
a new class, MachineInstrIndex, which hides arithmetic details from
most clients. This is a step towards allowing the register allocator
to update/insert code during allocation.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@81040 91177308-0d34-0410-b5e6-96231b3b80d8
2009-09-04 20:41:11 +00:00
Chris Lattner
45cfe545ec Change Pass::print to take a raw ostream instead of std::ostream,
update all code that this affects.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@79830 91177308-0d34-0410-b5e6-96231b3b80d8
2009-08-23 06:03:38 +00:00
Chris Lattner
c02497f5ba shoot a few more std::ostream print methods in the head.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@79814 91177308-0d34-0410-b5e6-96231b3b80d8
2009-08-23 03:47:42 +00:00
Chris Lattner
77942d4ee4 remove a dead class.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@79795 91177308-0d34-0410-b5e6-96231b3b80d8
2009-08-23 00:42:42 +00:00
David Greene
de0cc5a660 Add missing header.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@79463 91177308-0d34-0410-b5e6-96231b3b80d8
2009-08-19 20:52:54 +00:00
David Greene
b525766479 Re-apply LiveInterval index dumping patch, with fixes suggested by Bill
and others.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@78003 91177308-0d34-0410-b5e6-96231b3b80d8
2009-08-03 21:55:09 +00:00
David Greene
340482dcc0 Constify the key in Mi2IndexMap.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@76801 91177308-0d34-0410-b5e6-96231b3b80d8
2009-07-22 21:56:14 +00:00
Chris Lattner
3380d5c4aa revert r76602, 76603, and r76615, pending design discussions.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@76646 91177308-0d34-0410-b5e6-96231b3b80d8
2009-07-21 21:12:58 +00:00
David Greene
a358c1db5c Prefix IR dumps with LiveInterval indices when possible. This turns
this:

	%ESI<def> = MOV32rr %EDI<kill>
	ADJCALLSTACKDOWN64 0, %RSP<imp-def>, %EFLAGS<imp-def,dead>, %RSP<imp-use>
	%reg1027<def> = MOVZX64rr32 %ESI
	%reg1027<def> = ADD64ri8 %reg1027, 15, %EFLAGS<imp-def,dead>
	%reg1027<def> = AND64ri8 %reg1027, -16, %EFLAGS<imp-def,dead>
	%RDI<def> = MOV64rr %RSP
	%RDI<def> = SUB64rr %RDI, %reg1027<kill>, %EFLAGS<imp-def,dead>
	%RSP<def> = MOV64rr %RDI

into this:

4	%reg1024<def> = MOV32rr %EDI<kill>
12	ADJCALLSTACKDOWN64 0, %RSP<imp-def>, %EFLAGS<imp-def,dead>, %RSP<imp-use>
20	%reg1025<def> = MOVZX64rr32 %reg1024
28	%reg1026<def> = MOV64rr %reg1025<kill>
36	%reg1026<def> = ADD64ri8 %reg1026, 15, %EFLAGS<imp-def,dead>
44	%reg1027<def> = MOV64rr %reg1026<kill>
52	%reg1027<def> = AND64ri8 %reg1027, -16, %EFLAGS<imp-def,dead>
60	%reg1028<def> = MOV64rr %RSP
68	%reg1029<def> = MOV64rr %reg1028<kill>
76	%reg1029<def> = SUB64rr %reg1029, %reg1027<kill>, %EFLAGS<imp-def,dead>
84	%RSP<def> = MOV64rr %reg1029

This helps greatly when debugging register allocation and coalescing
problems.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@76615 91177308-0d34-0410-b5e6-96231b3b80d8
2009-07-21 18:56:32 +00:00
Lang Hames
ffd1326ff8 Improved tracking of value number kills. VN kills are now represented
as an (index,bool) pair. The bool flag records whether the kill is a
PHI kill or not. This code will be used to enable splitting of live
intervals containing PHI-kills.

A slight change to live interval weights introduced an extra spill
into lsr-code-insertion (outside the critical sections). The test 
condition has been updated to reflect this.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@75097 91177308-0d34-0410-b5e6-96231b3b80d8
2009-07-09 03:57:02 +00:00
Evan Cheng
2578ba26e7 Handle IMPLICIT_DEF with isUndef operand marker, part 2. This patch moves the code to annotate machineoperands to LiveIntervalAnalysis. It also add markers for implicit_def that define physical registers. The rest, is just a lot of details.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@74580 91177308-0d34-0410-b5e6-96231b3b80d8
2009-07-01 01:59:31 +00:00
Lang Hames
f41538d1b5 Update to in-place spilling framework. Includes live interval scaling and trivial rewriter.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@72729 91177308-0d34-0410-b5e6-96231b3b80d8
2009-06-02 16:53:25 +00:00
Evan Cheng
c781a243a3 In some rare cases, the register allocator can spill registers but end up not utilizing registers at all. The fundamental problem is linearscan's backtracking can end up freeing more than one allocated registers. However, reloads and restores might be folded into uses / defs and freed registers might not be used at all.
VirtRegMap keeps track of allocations so it knows what's not used. As a horrible hack, the stack coloring can color spill slots with *free* registers. That is, it replace reload and spills with copies from and to the free register. It unfold instructions that load and store the spill slot and replace them with register using variants.

Not yet enabled. This is part 1. More coming.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@70787 91177308-0d34-0410-b5e6-96231b3b80d8
2009-05-03 18:32:42 +00:00
Evan Cheng
5b69ebac85 It has finally happened. Spiller is now using live interval info.
This fixes a very subtle bug. vr defined by an implicit_def is allowed overlap with any register since it doesn't actually modify anything. However, if it's used as a two-address use, its live range can be extended and it can be spilled. The spiller must take care not to emit a reload for the vn number that's defined by the implicit_def. This is both a correctness and performance issue.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@69743 91177308-0d34-0410-b5e6-96231b3b80d8
2009-04-21 22:46:52 +00:00
Evan Cheng
2824a65550 Fix PR3391 and PR3864. Reg allocator infinite looping.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@67544 91177308-0d34-0410-b5e6-96231b3b80d8
2009-03-23 18:24:37 +00:00
Evan Cheng
0a1fcce092 Fix PR3486. Fix a bug in code that manually patch physical register live interval after its sub-register is coalesced with a virtual register.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@64082 91177308-0d34-0410-b5e6-96231b3b80d8
2009-02-08 11:04:35 +00:00
Owen Anderson
0c2e7b9ab6 Fix fallout from r62144. Evan, please double check this.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@62150 91177308-0d34-0410-b5e6-96231b3b80d8
2009-01-13 06:05:10 +00:00
Evan Cheng
8f90b6eb2f The coalescer does not coalesce a virtual register to a physical register if any of the physical register's sub-register live intervals overlaps with the virtual register. This is overly conservative. It prevents a extract_subreg from being coalesced away:
v1024 = EDI  // not killed
      =
      = EDI

One possible solution is for the coalescer to examine the sub-register live intervals in the same manner as the physical register. Another possibility is to examine defs and uses (when needed) of sub-registers. Both solutions are too expensive. For now, look for "short virtual intervals" and scan instructions to look for conflict instead.

This is a small win on x86-64. e.g. It shaves 403.gcc by ~80 instructions.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@61847 91177308-0d34-0410-b5e6-96231b3b80d8
2009-01-07 02:08:57 +00:00
Dan Gohman
d68a07650c Tidy up #includes, deleting a bunch of unnecessary #includes.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@61715 91177308-0d34-0410-b5e6-96231b3b80d8
2009-01-05 17:59:02 +00:00
Evan Cheng
d0e32c5d5c - Rewrite code that update register live interval that's split.
- Create and update spill slot live intervals.
- Lots of bug fixes.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@58367 91177308-0d34-0410-b5e6-96231b3b80d8
2008-10-29 05:06:14 +00:00
Evan Cheng
06587497dc Avoid splitting an interval multiple times; avoid splitting re-materializable val# (for now).
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@58068 91177308-0d34-0410-b5e6-96231b3b80d8
2008-10-24 02:05:00 +00:00
Evan Cheng
f5cd4f0d70 Committing a good chunk of the pre-register allocation live interval splitting pass. It's handling simple cases and appear to do good things. Next: avoid splitting an interval multiple times; renumber registers when possible; record stack slot live intervals for coloring; rematerialize defs when possible.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@58044 91177308-0d34-0410-b5e6-96231b3b80d8
2008-10-23 20:43:13 +00:00
Dan Gohman
f522068412 Trim #includes.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@57649 91177308-0d34-0410-b5e6-96231b3b80d8
2008-10-16 20:18:31 +00:00
Evan Cheng
dc37786595 Re-apply 56835 along with header file changes.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@56848 91177308-0d34-0410-b5e6-96231b3b80d8
2008-09-30 15:44:16 +00:00
Dale Johannesen
fa48f94130 Remove AsmThatEarlyClobber etc. from LiveIntervalAnalysis
and redo as linked list walk.  Logic moved into RA.
Per review feedback.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@56326 91177308-0d34-0410-b5e6-96231b3b80d8
2008-09-19 01:02:35 +00:00
Dale Johannesen
91aac1015e Add a bit to mark operands of asm's that conflict
with an earlyclobber operand elsewhere.  Propagate
this bit and the earlyclobber bit through SDISel.
Change linear-scan RA not to allocate regs in a way 
that conflicts with an earlyclobber.  See also comments.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@56290 91177308-0d34-0410-b5e6-96231b3b80d8
2008-09-17 21:13:11 +00:00
Dan Gohman
ae73dc1448 Tidy up several unbeseeming casts from pointer to intptr_t.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@55779 91177308-0d34-0410-b5e6-96231b3b80d8
2008-09-04 17:05:41 +00:00
Chris Lattner
2dba6a1bdb consolidate DenseMapInfo implementations, and add one for std::pair.
Patch contributed by m-s.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@55167 91177308-0d34-0410-b5e6-96231b3b80d8
2008-08-22 05:08:25 +00:00
Owen Anderson
d6664311ac Resurrect some ancient code to add spill ranges without attempting folding, remat, or splitting. This code has been updated to current APIs
in so far as it compiles and, in theory, works, but does not take advantage of recent advancements.  For instance, it could be improved by using
MachineRegisterInfo::use_iterator.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@54924 91177308-0d34-0410-b5e6-96231b3b80d8
2008-08-18 18:05:32 +00:00
Owen Anderson
289983123b Expunge the last uses of std::map from LiveIntervals.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@54766 91177308-0d34-0410-b5e6-96231b3b80d8
2008-08-13 22:28:50 +00:00
Owen Anderson
20e2839cb9 Move r2iMap_ over to DenseMap from std::map.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@54765 91177308-0d34-0410-b5e6-96231b3b80d8
2008-08-13 22:08:30 +00:00
Owen Anderson
03857b29d8 Make the allocation of LiveIntervals explicit, rather than holding them in the r2iMap_ by value. This will prevent references to them from being invalidated
if the map is changed.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@54763 91177308-0d34-0410-b5e6-96231b3b80d8
2008-08-13 21:49:13 +00:00
Owen Anderson
49bfdd63f4 Switch this from std::map to DenseMap.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@54761 91177308-0d34-0410-b5e6-96231b3b80d8
2008-08-13 21:24:24 +00:00
Matthijs Kooijman
b3e15c0008 Silence a warning.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@54462 91177308-0d34-0410-b5e6-96231b3b80d8
2008-08-07 13:36:30 +00:00
Dan Gohman
ca425a2a98 Reword a comment to be less ambiguous.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@54135 91177308-0d34-0410-b5e6-96231b3b80d8
2008-07-28 18:42:57 +00:00
Dan Gohman
6d69ba8a69 Enable rematerialization of constants using AliasAnalysis::pointsToConstantMemory,
and knowledge of PseudoSourceValues. This unfortunately isn't sufficient to allow
constants to be rematerialized in PIC mode -- the extra indirection is a
complication.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@54000 91177308-0d34-0410-b5e6-96231b3b80d8
2008-07-25 00:02:30 +00:00