Commit Graph

192 Commits

Author SHA1 Message Date
Saleem Abdulrasool 7230b377df CodeGen: silence a C++11 feature warning
llvm-svn: 198133
2013-12-28 22:47:55 +00:00
Andrew Trick 7afe481801 Uninitialized variable (in never taken path) after factoring.
llvm-svn: 198131
2013-12-28 22:25:57 +00:00
Andrew Trick 33e05d7665 Added debugging options: -misched-only-func/block
llvm-svn: 198124
2013-12-28 21:57:02 +00:00
Andrew Trick d14d7c20f5 Add a PostMachineScheduler pass with generic implementation.
PostGenericScheduler uses either the new machine model or the hazard
checker for top-down scheduling. Most of the infrastructure for PreRA
machine scheduling is reused.

With a some tuning, this should allow MachineScheduler to be default
for all ARM targets, including cortex-A9, using the new machine
model. Likewise, with additional tuning, it should be able to replace
PostRAScheduler for all targets.

The PostMachineScheduler pass does not currently run the
AntiDepBreaker. There is less need for it on targets that are already
running preRA MachineScheduler. I want to prove it's necessary before
committing to the maintenance burden.

The PostMachineScheduler also currently removes kill flags and adds
them all back later. This is a bit ridiculous. I'd prefer passes to
directly use a liveness utility than rely on flags.

A test case that enables this scheduler will be included in a
subsequent checkin that updates the A9 model.

llvm-svn: 198122
2013-12-28 21:56:57 +00:00
Andrew Trick 17080b9bf2 Stub out a PostMachineScheduler pass.
Placeholder and boilerplate for a PostRA MachineScheduler pass.

llvm-svn: 198120
2013-12-28 21:56:51 +00:00
Andrew Trick d7f890edb0 Factor MI-Sched in preparation for post-ra scheduling support.
Factor the MachineFunctionPass into MachineSchedulerBase.

Split the DAG class into ScheduleDAGMI and SchedulerDAGMILive.

llvm-svn: 198119
2013-12-28 21:56:47 +00:00
Andrew Trick fc127d1197 Factor out the SchedRemainder/SchedBoundary from GenericScheduler strategy.
These helper classes take care of the book-keeping the drives the
GenericScheduler heuristics. It is likely that developers writing
target-specific schedulers that work similarly to GenericScheduler
will want to use these helpers too. The immediate goal is to develop a
GenericPostScheduler that can run in place of the old PostRAScheduler,
but will use the new machine model.

No functionality change intended.

llvm-svn: 196643
2013-12-07 05:59:44 +00:00
Andrew Trick f7760a24e5 comment grammar
llvm-svn: 196585
2013-12-06 17:19:20 +00:00
Daniel Jasper 0d92abdfd2 Fix bug introduced in r196517.
Not only does it trigger -Wparentheses, I think the assert actually
relies on incorrect operator precedence.

Also, the grammar as questionable, but I might not know enough about the
problem at hand.

llvm-svn: 196567
2013-12-06 08:58:22 +00:00
Andrew Trick 5a22df498e MI-Sched: Model "reserved" processor resources.
This allows a target to use MI-Sched as an in-order scheduler that
will model strict resource conflicts without defining a processor
itinerary. Instead, the target can now use the new per-operand machine
model and define in-order resources with BufferSize=0. For example,
this would allow restricting the type of operations that can be formed
into a dispatch group. (Normally NumMicroOps is sufficient to enforce
dispatch groups).

If the intent is to model latency in in-order pipeline, as opposed to
resource conflicts, then a resource with BufferSize=1 should be
defined instead.

This feature is only casually tested as there are no in-tree targets
using it yet. However, Hal will be experimenting with POWER7.

llvm-svn: 196517
2013-12-05 17:56:02 +00:00
Andrew Trick 880e573d98 MI-Sched: handle latency of in-order operations with the new machine model.
The per-operand machine model allows the target to define "unbuffered"
processor resources. This change is a quick, cheap way to model stalls
caused by the latency of operations that use such resources. This only
applies when the processor's micro-op buffer size is non-zero
(Out-of-Order). We can't precisely model in-order stalls during
out-of-order execution, but this is an easy and effective
heuristic. It benefits cortex-a9 scheduling when using the new
machine model, which is not yet on by default.

MI-Sched for armv7 was evaluated on Swift (and only not enabled because
of a performance bug related to predication). However, we never
evaluated Cortex-A9 performance on MI-Sched in its current form. This
change adds MI-Sched functionality to reach performance goals on
A9. The only remaining change is to allow MI-Sched to run as a PostRA
pass.

I evaluated performance using a set of options to estimate the performance impact once MI sched is default on armv7:
-mcpu=cortex-a9 -disable-post-ra -misched-bench -scheditins=false

For a simple saxpy loop I see a 1.7x speedup. Here are the llvm-testsuite results:
(min run time over 2 runs, filtering tiny changes)

Speedups:
| Benchmarks/BenchmarkGame/recursive         |  52.39% |
| Benchmarks/VersaBench/beamformer           |  20.80% |
| Benchmarks/Misc/pi                         |  19.97% |
| Benchmarks/Misc/mandel-2                   |  19.95% |
| SPEC/CFP2000/188.ammp                      |  18.72% |
| Benchmarks/McCat/08-main/main              |  18.58% |
| Benchmarks/Misc-C++/Large/sphereflake      |  18.46% |
| Benchmarks/Olden/power                     |  17.11% |
| Benchmarks/Misc-C++/mandel-text            |  16.47% |
| Benchmarks/Misc/oourafft                   |  15.94% |
| Benchmarks/Misc/flops-7                    |  14.99% |
| Benchmarks/FreeBench/distray               |  14.26% |
| SPEC/CFP2006/470.lbm                       |  14.00% |
| mediabench/mpeg2/mpeg2dec/mpeg2decode      |  12.28% |
| Benchmarks/SmallPT/smallpt                 |  10.36% |
| Benchmarks/Misc-C++/Large/ray              |   8.97% |
| Benchmarks/Misc/fp-convert                 |   8.75% |
| Benchmarks/Olden/perimeter                 |   7.10% |
| Benchmarks/Bullet/bullet                   |   7.03% |
| Benchmarks/Misc/mandel                     |   6.75% |
| Benchmarks/Olden/voronoi                   |   6.26% |
| Benchmarks/Misc/flops-8                    |   5.77% |
| Benchmarks/Misc/matmul_f64_4x4             |   5.19% |
| Benchmarks/MiBench/security-rijndael       |   5.15% |
| Benchmarks/Misc/flops-6                    |   5.10% |
| Benchmarks/Olden/tsp                       |   4.46% |
| Benchmarks/MiBench/consumer-lame           |   4.28% |
| Benchmarks/Misc/flops-5                    |   4.27% |
| Benchmarks/mafft/pairlocalalign            |   4.19% |
| Benchmarks/Misc/himenobmtxpa               |   4.07% |
| Benchmarks/Misc/lowercase                  |   4.06% |
| SPEC/CFP2006/433.milc                      |   3.99% |
| Benchmarks/tramp3d-v4                      |   3.79% |
| Benchmarks/FreeBench/pifft                 |   3.66% |
| Benchmarks/Ptrdist/ks                      |   3.21% |
| Benchmarks/Adobe-C++/loop_unroll           |   3.12% |
| SPEC/CINT2000/175.vpr                      |   3.12% |
| Benchmarks/nbench                          |   2.98% |
| SPEC/CFP2000/183.equake                    |   2.91% |
| Benchmarks/Misc/perlin                     |   2.85% |
| Benchmarks/Misc/flops-1                    |   2.82% |
| Benchmarks/Misc-C++-EH/spirit              |   2.80% |
| Benchmarks/Misc/flops-2                    |   2.77% |
| Benchmarks/NPB-serial/is                   |   2.42% |
| Benchmarks/ASC_Sequoia/CrystalMk           |   2.33% |
| Benchmarks/BenchmarkGame/n-body            |   2.28% |
| Benchmarks/SciMark2-C/scimark2             |   2.27% |
| Benchmarks/Olden/bh                        |   2.03% |
| skidmarks10/skidmarks                      |   1.81% |
| Benchmarks/Misc/flops                      |   1.72% |

Slowdowns:
| Benchmarks/llubenchmark/llu                | -14.14% |
| Benchmarks/Polybench/stencils/seidel-2d    |  -5.67% |
| Benchmarks/Adobe-C++/functionobjects       |  -5.25% |
| Benchmarks/Misc-C++/oopack_v1p8            |  -5.00% |
| Benchmarks/Shootout/hash                   |  -2.35% |
| Benchmarks/Prolangs-C++/ocean              |  -2.01% |
| Benchmarks/Polybench/medley/floyd-warshall |  -1.98% |
| Polybench/linear-algebra/kernels/3mm       |  -1.95% |
| Benchmarks/McCat/09-vor/vor                |  -1.68% |

llvm-svn: 196516
2013-12-05 17:55:58 +00:00
Andrew Trick bb1247b9f0 comment typo and reformat
llvm-svn: 196513
2013-12-05 17:55:47 +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 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 dc4c1adfc7 Comment typo.
llvm-svn: 191312
2013-09-24 17:11:19 +00:00
Andrew Trick 978674b2bc Allow subtarget selection of the default MachineScheduler and document the interface.
The global registry is used to allow command line override of the
scheduler selection, but does not work well as the normal selection
API. For example, the same LLVM process should be able to target
multiple targets or subtargets.

llvm-svn: 191071
2013-09-20 05:14:41 +00:00
Andrew Trick 665d3ec3d3 Rename ConvergingScheduler to GenericScheduler.
This was an experimental scheduler a year ago. It's now used by
several subtargets, both in-order and out-of-order, and it
is about to be enabled by default for x86 and armv7. It will be the
new GenericScheduler for subtargets that don't provide their own
SchedulingStrategy.

llvm-svn: 191051
2013-09-19 23:10:59 +00:00
Andrew Trick 6c88b35090 Enable -misched-cyclicpath by default.
llvm-svn: 190367
2013-09-09 23:31:14 +00:00
Andrew Trick e1f7bf2c02 mi-sched: smooth out the cyclicpath heuristic.
Arnold's idea.

I generally try to avoid stateful heuristics because it can make
debugging harder. However, we need a way to prevent the latency
priority from dominating, and it somewhat makes sense to schedule
aggressively for latency only within an issue group.

Swift in particular likes this, and it doesn't hurt anyone else:
| Benchmarks/MiBench/consumer-lame              |  10.39% |
| Benchmarks/Misc/himenobmtxpa                  |   9.63% |

llvm-svn: 190360
2013-09-09 22:28:08 +00:00
Andrew Trick b248b4a1de mi-sched: cleanup register pressure update, remove a FIXME.
llvm-svn: 190181
2013-09-06 17:32:47 +00:00
Andrew Trick c573cd905a mi-sched: improve regpressure tracing.
llvm-svn: 190180
2013-09-06 17:32:44 +00:00
Andrew Trick 7609b7d1b5 mi-sched: print tree size in -view-misched-dags
llvm-svn: 190179
2013-09-06 17:32:42 +00:00
Andrew Trick ffdbefb90c mi-sched: register pressure update tracing.
llvm-svn: 190178
2013-09-06 17:32:39 +00:00