Commit Graph

12 Commits

Author SHA1 Message Date
Dan Gohman
79ce276083 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.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@62275 91177308-0d34-0410-b5e6-96231b3b80d8
2009-01-15 19:20:50 +00:00
Evan Cheng
c29a56dedb Fix PR3241: Currently EmitCopyFromReg emits a copy from the physical register to a virtual register unless it requires an expensive cross class copy. That means we are only treating "expensive to copy" register dependency as physical register dependency.
Also future proof the scheduler to handle "normal" physical register dependencies. The code is not exercised yet.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@62074 91177308-0d34-0410-b5e6-96231b3b80d8
2009-01-12 03:19:55 +00:00
Evan Cheng
9aacec1f26 CheckForPhysRegDependency should not return copy cost. It's not used. No functionality change.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@62036 91177308-0d34-0410-b5e6-96231b3b80d8
2009-01-11 08:53:35 +00:00
Dan Gohman
c9a5b9e38b Rename BuildSchedUnits to BuildSchedGraph, and refactor the
code in ScheduleDAGSDNodes' BuildSchedGraph into separate functions.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@61376 91177308-0d34-0410-b5e6-96231b3b80d8
2008-12-23 18:36:58 +00:00
Dan Gohman
e1dfc7da89 Avoid an unnecessary call to allnodes_size(), which is linear.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@61372 91177308-0d34-0410-b5e6-96231b3b80d8
2008-12-23 17:24:50 +00:00
Dan Gohman
89b64bd7e5 Double the amount of memory reserved for SUnits. This is a
temporary workaround for an obscure bug. When node cloning is
used, it is possible that more SUnits will be created, and
if the SUnits std::vector has to reallocate, it will
invalidate all the graph edges.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@61122 91177308-0d34-0410-b5e6-96231b3b80d8
2008-12-17 04:30:46 +00:00
Dan Gohman
9a65d6afc2 Remove some special-case logic in ScheduleDAGSDNodes's
latency computation code that is no longer needed with the
new method for handling latencies.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@61074 91177308-0d34-0410-b5e6-96231b3b80d8
2008-12-16 03:31:11 +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
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
787782f4ca Use ComputeLatency in the MachineInstr scheduler.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@59777 91177308-0d34-0410-b5e6-96231b3b80d8
2008-11-21 01:44:51 +00:00
Dan Gohman
c8c2827993 Implement ComputeLatency for MachineInstr ScheduleDAGs. Factor
some of the latency computation logic out of the SDNode
ScheduleDAG code into a TargetInstrItineraries helper method
to help with this.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@59761 91177308-0d34-0410-b5e6-96231b3b80d8
2008-11-21 00:12:10 +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