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

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

that used this header to select a scheduling policy should
use SchedulerRegistry.h instead (llvm-gcc and clang were
updated a while ago).

llvm-svn: 63934

elements, even if it is only to take the address.  Test:
break-anti-dependencies.ll with ENABLE_EXPENSIVE_CHECKS.

llvm-svn: 62576

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

code in ScheduleDAGSDNodes' BuildSchedGraph into separate functions.

llvm-svn: 61376

reallocations. We don't do cloning on MachineInstr schedule DAGs,
but this is a worthwhile sanity check regardless.

llvm-svn: 61343

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

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

some of the latency computation logic out of the SDNode
ScheduleDAG code into a TargetInstrItineraries helper method
to help with this.

llvm-svn: 59761

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