Commit Graph

16 Commits

Author SHA1 Message Date
Andrew Trick
953be893e8 misched preparation: rename core scheduler methods for consistency.
We had half the API with one convention, half with another. Now was a
good time to clean it up.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@152255 91177308-0d34-0410-b5e6-96231b3b80d8
2012-03-07 23:00:49 +00:00
Andrew Trick
b4566a9999 Initialize SUnits before DAG building.
Affect on SD scheduling and postRA scheduling:
Printing the DAG will display the nodes in top-down topological order.
This matches the order within the MBB and makes my life much easier in general.

Affect on misched:
We don't need to track virtual register uses at all. This is awesome.
I also intend to rely on the SUnit ID as a topo-sort index. So if A < B then we cannot have an edge B -> A.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@151135 91177308-0d34-0410-b5e6-96231b3b80d8
2012-02-22 06:08:11 +00:00
Andrew Trick
2da8bc8a5f 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.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@122541 91177308-0d34-0410-b5e6-96231b3b80d8
2010-12-24 05:03:26 +00:00
Andrew Trick
6e8f4c4048 whitespace
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@122539 91177308-0d34-0410-b5e6-96231b3b80d8
2010-12-24 04:28:06 +00:00
Oscar Fuentes
10e02a017a Use llvm::next' instead of next' to make VC++ 2010 happy.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@105168 91177308-0d34-0410-b5e6-96231b3b80d8
2010-05-30 13:14:21 +00:00
Dan Gohman
93d3433579 Eliminate the use of PriorityQueue and just use a std::vector,
implementing pop with a linear search for a "best" element. The priority
queue was a neat idea, but in practice the comparison functions depend
on dynamic information.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@104718 91177308-0d34-0410-b5e6-96231b3b80d8
2010-05-26 18:52:00 +00:00
Dan Gohman
a4e4ffd389 Change push_all to a non-virtual function and implement it in the
base class, since all the implementations are the same.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@104659 91177308-0d34-0410-b5e6-96231b3b80d8
2010-05-26 01:10:55 +00:00
David Goodwin
557bbe6b5d 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.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@89471 91177308-0d34-0410-b5e6-96231b3b80d8
2009-11-20 19:32:48 +00:00
David Goodwin
12dd99dc30 Rename registers to break output dependencies in addition to anti-dependencies.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@87015 91177308-0d34-0410-b5e6-96231b3b80d8
2009-11-12 19:08:21 +00:00
David Goodwin
4de099d8ca Do a scheduling pass ignoring anti-dependencies to identify candidate registers that should be renamed.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@85939 91177308-0d34-0410-b5e6-96231b3b80d8
2009-11-03 20:57:50 +00:00
Dan Gohman
8749b61178 Add initial support for back-scheduling address computations,
especially in the case of addresses computed from loop induction
variables.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@61075 91177308-0d34-0410-b5e6-96231b3b80d8
2008-12-16 03:35:01 +00:00
Dan Gohman
3f23744df4 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.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@61073 91177308-0d34-0410-b5e6-96231b3b80d8
2008-12-16 03:25:46 +00:00
Dan Gohman
f55a2101e3 Update CalcLatency to work in terms of edge latencies, rather than
node latencies. Use CalcLatency instead of manual code in
CalculatePriorities to keep it consistent. Previously it
computed slightly different results.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@60817 91177308-0d34-0410-b5e6-96231b3b80d8
2008-12-10 00:24:36 +00:00
Dan Gohman
54e4c36a73 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.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@60806 91177308-0d34-0410-b5e6-96231b3b80d8
2008-12-09 22:54:47 +00:00
Dan Gohman
aeac8f9cb4 Don't charge full latency for an anti-dependence, in this simplistic
pipeline model.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@60733 91177308-0d34-0410-b5e6-96231b3b80d8
2008-12-09 00:26:46 +00:00
Dan Gohman
343f0c0467 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.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@59676 91177308-0d34-0410-b5e6-96231b3b80d8
2008-11-19 23:18:57 +00:00