Commit Graph

31 Commits

Author SHA1 Message Date
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
Chris Lattner
7896c9f436 improve portability to avoid conflicting with std::next in c++'0x.
Patch by Howard Hinnant!


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@90365 91177308-0d34-0410-b5e6-96231b3b80d8
2009-12-03 00:50:42 +00:00
Lang Hames
8783e401a3 Removed references to LiveStacks from Spiller.* . They're no longer needed.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@89422 91177308-0d34-0410-b5e6-96231b3b80d8
2009-11-20 00:53:30 +00:00
Lang Hames
835ca07991 Added a new Spiller implementation which wraps LiveIntervals::addIntervalsForSpills.
All spiller calls in RegAllocLinearScan now go through the new Spiller interface.
The "-new-spill-framework" command line option has been removed. To use the trivial in-place spiller you should now pass "-spiller=trivial -rewriter=trivial".
(Note the trivial spiller/rewriter are only meant to serve as examples of the new in-place modification work. Enabling them will yield terrible, though hopefully functional, code).


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@89311 91177308-0d34-0410-b5e6-96231b3b80d8
2009-11-19 04:15:33 +00:00
Lang Hames
38283e23df Fixed the in-place spiller and trivial rewriter, which had been broken by the recent SlotIndexes work.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@89238 91177308-0d34-0410-b5e6-96231b3b80d8
2009-11-18 20:31:20 +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
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
Lang Hames
6cc91e39c0 Oops. Renamed remaining MachineInstrIndex references.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@83255 91177308-0d34-0410-b5e6-96231b3b80d8
2009-10-03 04:31:31 +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
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
Bill Wendling
c75e7d2a06 Convert DOUT to DEBUG(errs()...).
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@79766 91177308-0d34-0410-b5e6-96231b3b80d8
2009-08-22 20:54:03 +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
Lang Hames
6bbc73d3fd Completed basic intra block split implementation.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@74114 91177308-0d34-0410-b5e6-96231b3b80d8
2009-06-24 20:46:24 +00:00
Lang Hames
10382fb71d More VNInfo tweaking, plus a little progress on intra-block splitting.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@73750 91177308-0d34-0410-b5e6-96231b3b80d8
2009-06-19 02:17:53 +00:00
Lang Hames
857c4e01f8 VNInfo cleanup.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@73634 91177308-0d34-0410-b5e6-96231b3b80d8
2009-06-17 21:01:20 +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
Lang Hames
e2b201bac3 New Spiller interface and trivial implementation.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@72030 91177308-0d34-0410-b5e6-96231b3b80d8
2009-05-18 19:03:16 +00:00
Lang Hames
87e3bcab73 Renamed Spiller classes (plus uses and related files) to VirtRegRewriter.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@71057 91177308-0d34-0410-b5e6-96231b3b80d8
2009-05-06 02:36:21 +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
276b77e66c Teach spiller to unfold instructions which modref spill slot when a scratch
register is available and when it's profitable.

e.g.
     xorq  %r12<kill>, %r13
     addq  %rax, -184(%rbp)
     addq  %r13, -184(%rbp)
==>
     xorq  %r12<kill>, %r13
     movq  -184(%rbp), %r12
     addq  %rax, %r12
     addq  %r13, %r12
     movq  %r12, -184(%rbp)

Two more instructions, but fewer memory accesses. It can also open up
opportunities for more optimizations.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@69341 91177308-0d34-0410-b5e6-96231b3b80d8
2009-04-17 01:29:40 +00:00
Dan Gohman
9a77a92859 When assigning a physical register to a MachineOperand, set
the subreg field to 0, since the subreg field is only used
for virtual register subregs. This doesn't change
current functionality; it just eliminates bogus noise from
debug output.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@68955 91177308-0d34-0410-b5e6-96231b3b80d8
2009-04-13 15:21:32 +00:00
Bob Wilson
d9df501704 Fix pr3954. The register scavenger asserts for inline assembly with
register destinations that are tied to source operands.  The
TargetInstrDescr::findTiedToSrcOperand method silently fails for inline
assembly.  The existing MachineInstr::isRegReDefinedByTwoAddr was very
close to doing what is needed, so this revision makes a few changes to
that method and also renames it to isRegTiedToUseOperand (for consistency
with the very similar isRegTiedToDefOperand and because it handles both
two-address instructions and inline assembly with tied registers).


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@68714 91177308-0d34-0410-b5e6-96231b3b80d8
2009-04-09 17:16:43 +00:00
Bill Wendling
e67f5e4273 Oy! When reverting r68073, I added in experimental code. Sorry...
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@68099 91177308-0d34-0410-b5e6-96231b3b80d8
2009-03-31 08:41:31 +00:00
Bill Wendling
8fe00540fc Revert r68073. It's causing a failure in the Apple-style builds.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@68092 91177308-0d34-0410-b5e6-96231b3b80d8
2009-03-31 08:26:26 +00:00
Bill Wendling
fd302b7056 Balance out quote in debug output.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@68059 91177308-0d34-0410-b5e6-96231b3b80d8
2009-03-30 20:32:22 +00:00
Sanjiv Gupta
91520ea585 Fixed build warnings for unused variables.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@67372 91177308-0d34-0410-b5e6-96231b3b80d8
2009-03-20 13:49:20 +00:00
Evan Cheng
a24752ff43 Added MachineInstr::isRegTiedToDefOperand to check for two-addressness.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@67335 91177308-0d34-0410-b5e6-96231b3b80d8
2009-03-19 20:30:06 +00:00
Evan Cheng
e47b0089d9 Spiller may unfold load / mod / store instructions as an optimization when the would be loaded value is available in a register. It needs to check if it's legal to clobber the register. Also, the register can contain values of multiple spill slots, make sure to check all instead of just the one being unfolded.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@67068 91177308-0d34-0410-b5e6-96231b3b80d8
2009-03-17 01:23:09 +00:00
Daniel Dunbar
cfbf05ef03 Add newlines at end of file (this can annoy gcov)
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@67000 91177308-0d34-0410-b5e6-96231b3b80d8
2009-03-14 01:53:05 +00:00
Owen Anderson
0ff4e2105b Reorganize some #include's.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@66780 91177308-0d34-0410-b5e6-96231b3b80d8
2009-03-12 06:58:19 +00:00
Owen Anderson
1ed5b714f1 Reorganization: Move the Spiller out of VirtRegMap.cpp into its own files. No (intended) functionality change.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@66720 91177308-0d34-0410-b5e6-96231b3b80d8
2009-03-11 22:31:21 +00:00