Commit Graph

36 Commits

Author SHA1 Message Date
Andrew Trick c94056692a Fix a few cases where the scheduler is not checking for phys reg copies. The scheduling node may have a NULL DAG node, yuck.
llvm-svn: 122544
2010-12-24 06:46:50 +00:00
Andrew Trick 10ffc2b6c2 Various bits of framework needed for precise machine-level selection
DAG scheduling during isel. Most new functionality is currently
guarded by -enable-sched-cycles and -enable-sched-hazard.

Added InstrItineraryData::IssueWidth field, currently derived from
ARM itineraries, but could be initialized differently on other targets.

Added ScheduleHazardRecognizer::MaxLookAhead to indicate whether it is
active, and if so how many cycles of state it holds.

Added SchedulingPriorityQueue::HasReadyFilter to allowing gating entry
into the scheduler's available queue.

ScoreboardHazardRecognizer now accesses the ScheduleDAG in order to
get information about it's SUnits, provides RecedeCycle for bottom-up
scheduling, correctly computes scoreboard depth, tracks IssueCount, and
considers potential stall cycles when checking for hazards.

ScheduleDAGRRList now models machine cycles and hazards (under
flags). It tracks MinAvailableCycle, drives the hazard recognizer and
priority queue's ready filter, manages a new PendingQueue, properly
accounts for stall cycles, etc.

llvm-svn: 122541
2010-12-24 05:03:26 +00:00
Chris Lattner ed69c6e4b9 reduce indentation, no functionality change.
llvm-svn: 122208
2010-12-20 00:50:16 +00:00
John Mosby 5364655e02 Remove trailing whitespace, no functionality changes.
llvm-svn: 107244
2010-06-30 03:40:54 +00:00
Zhongxing Xu 188855abef Remove unused member variable.
llvm-svn: 103936
2010-05-17 09:47:55 +00:00
Dan Gohman 39305067ad Delete an unused member variable.
llvm-svn: 101143
2010-04-13 16:51:39 +00:00
David Greene 94745d0d10 Change errs() to dbgs().
llvm-svn: 92585
2010-01-05 01:25:41 +00:00
David Goodwin 80a03cc0b1 Remove some old experimental code that is no longer needed. Remove additional, speculative scheduling pass as its cost did not translate into significant performance improvement. Minor tweaks.
llvm-svn: 89471
2009-11-20 19:32:48 +00:00
David Goodwin da83f7d58b Rename registers to break output dependencies in addition to anti-dependencies.
llvm-svn: 87015
2009-11-12 19:08:21 +00:00
David Goodwin 8501dbbe10 Do a scheduling pass ignoring anti-dependencies to identify candidate registers that should be renamed.
llvm-svn: 85939
2009-11-03 20:57:50 +00:00
Reid Kleckner 8ff5c19ebd Fix integer overflow in instruction scheduling. This can happen if we have
basic blocks that are so long that their size overflows a short.

Also assert that overflow does not happen in the future, as requested by Evan.

This fixes PR4401.

llvm-svn: 83159
2009-09-30 20:15:38 +00:00
Bill Wendling 214ac545ab Convert DOUT to DEBUG(errs()...).
llvm-svn: 79760
2009-08-22 20:41:06 +00:00
David Goodwin ebd694bb0a Add some debug output.
llvm-svn: 78687
2009-08-11 17:35:23 +00:00
Daniel Dunbar 8ef0735dd5 Move to raw_ostream.
llvm-svn: 76963
2009-07-24 09:53:24 +00:00
Dan Gohman dfaf646c34 When scheduling a block in parts, keep track of the overall
instruction index across each part. Instruction indices are used
to make live range queries, and live ranges can extend beyond
scheduling region boundaries.

Refactor the ScheduleDAGSDNodes class some more so that it
doesn't have to worry about this additional information.

llvm-svn: 64288
2009-02-11 04:27:20 +00:00
Dan Gohman 27fa408b64 Use iterators to iterate through the Preds array instead of
an index. This code is on the hot-path because the current
way SDep edges are uniqued has quadratic complexity.

llvm-svn: 64262
2009-02-11 00:12:28 +00:00
Dan Gohman b95434356c Factor out more code for computing register live-range informationfor
scheduling, and generalize is so that preserves state across
scheduling regions. This fixes incorrect live-range information around
terminators and labels, which are effective region boundaries.

In place of looking for terminators to anchor inter-block dependencies,
introduce special entry and exit scheduling units for this purpose.

llvm-svn: 64254
2009-02-10 23:27:53 +00:00
Dan Gohman 5f8a2598b2 Instead of adding dependence edges between terminator instructions
and every other instruction in their blocks to keep the terminator
instructions at the end, teach the post-RA scheduler how to operate
on ranges of instructions, and exclude terminators from the range
of instructions that get scheduled.

Also, exclude mid-block labels, such as EH_LABEL instructions, and
schedule code before them separately from code after them. This
fixes problems with the post-RA scheduler moving code past
EH_LABELs.

llvm-svn: 62366
2009-01-16 22:10:20 +00:00
Dan Gohman 7e105f0b12 Generalize the HazardRecognizer interface so that it can be used
to support MachineInstr-based scheduling in addition to
SDNode-based scheduling.

llvm-svn: 62284
2009-01-15 22:18:12 +00:00
Dan Gohman 619ef48a52 Move a few containers out of ScheduleDAGInstrs::BuildSchedGraph
and into the ScheduleDAGInstrs class, so that they don't get
destructed and re-constructed for each block. This fixes a
compile-time hot spot in the post-pass scheduler.

To help facilitate this, tidy and do some minor reorganization
in the scheduler constructor functions.

llvm-svn: 62275
2009-01-15 19:20:50 +00:00
Dan Gohman 13141d5538 Avoid referring to edge D after the Succs or Preds arrays have
been modified, to avoid trouble in the (unlikely) scenario that
D is a reference to an element in one of those arrays.

llvm-svn: 62173
2009-01-13 19:08:45 +00:00
Dan Gohman 52d4d8244b Don't call setDepthDirty/setHeightDirty when adding an edge
with latency 0, since it doesn't affect the depth or height.

llvm-svn: 61762
2009-01-05 22:40:26 +00:00
Dan Gohman 3a57213e38 Minor code simplifications.
llvm-svn: 61371
2008-12-23 17:22:32 +00:00
Dan Gohman a04542b61e Optimize setDepthDirty and setHeightDirty a little, as they showed
up on a profile.

llvm-svn: 61344
2008-12-22 21:11:33 +00:00
Dan Gohman 24fe9a1dc2 Use SmallVector's pop_back_val.
llvm-svn: 61277
2008-12-20 16:42:33 +00:00
Dan Gohman bb92a1b815 Use the correct Preds and Succs lists in setHeightDirty()
and setDepthDirty(), respectively. This fixes PR3241.

llvm-svn: 61276
2008-12-20 16:34:57 +00:00
Dan Gohman 2a16bbe394 Use getDepth() and getHeight() instead of accessing the
Depth and Height members directly, as they may not be
current.

llvm-svn: 61121
2008-12-17 04:25:52 +00:00
Dan Gohman dddc1ac7ea Fix some register-alias-related bugs in the post-RA scheduler liveness
computation code. Also, avoid adding output-depenency edges when both
defs are dead, which frequently happens with EFLAGS defs.

Compute Depth and Height lazily, and always in terms of edge latency
values. For the schedulers that don't care about latency, edge latencies
are set to 1.

Eliminate Cycle and CycleBound, and LatencyPriorityQueue's Latencies array.
These are all subsumed by the Depth and Height fields.

llvm-svn: 61073
2008-12-16 03:25:46 +00:00
Dan Gohman e3a6351f34 Move addPred and removePred out-of-line.
llvm-svn: 61067
2008-12-16 01:05:52 +00:00
Dan Gohman 2d170896ee Rewrite the SDep class, and simplify some of the related code.
The Cost field is removed. It was only being used in a very limited way,
to indicate when the scheduler should attempt to protect a live register,
and it isn't really needed to do that. If we ever want the scheduler to
start inserting copies in non-prohibitive situations, we'll have to
rethink some things anyway.

A Latency field is added. Instead of giving each node a single
fixed latency, each edge can have its own latency. This will eventually
be used to model various micro-architecture properties more accurately.

The PointerIntPair class and an internal union are now used, which
reduce the overall size.

llvm-svn: 60806
2008-12-09 22:54:47 +00:00
Dan Gohman 7d32974069 Whitespace cleanups.
llvm-svn: 60769
2008-12-09 16:37:48 +00:00
Dan Gohman ad2134d45d Initial support for anti-dependence breaking. Currently this code does not
introduce any new spilling; it just uses unused registers.

Refactor the SUnit topological sort code out of the RRList scheduler and
make use of it to help with the post-pass scheduler.

llvm-svn: 59999
2008-11-25 00:52:40 +00:00
Dan Gohman 67b35bd4d1 Rename SDep's isSpecial to isArtificial, to make this field a little
less mysterious.

llvm-svn: 59782
2008-11-21 02:18:56 +00:00
Dan Gohman 866b034839 Add #include <climits> to get the definition of INT_MAX.
llvm-svn: 59692
2008-11-20 01:41:34 +00:00
Dan Gohman 4ce15e12b9 Factor out the code for verifying the work of the scheduler,
extend it a bit, and make use of it in all schedulers, to
ensure consistent checking.

llvm-svn: 59689
2008-11-20 01:26:25 +00:00
Dan Gohman 60cb69e665 Experimental post-pass scheduling support. Post-pass scheduling
is currently off by default, and can be enabled with
-disable-post-RA-scheduler=false.

This doesn't have a significant impact on most code yet because it doesn't
yet do anything to address anti-dependencies and it doesn't attempt to
disambiguate memory references. Also, several popular targets
don't have pipeline descriptions yet.

The majority of the changes here are splitting the SelectionDAG-specific
code out of ScheduleDAG, so that ScheduleDAG can be moved to
libLLVMCodeGen.a. The interface between ScheduleDAG-using code and
the rest of the scheduling code is somewhat rough and will evolve.

llvm-svn: 59676
2008-11-19 23:18:57 +00:00