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

llvm-svn: 63941

that previously included this header should include
SchedulerRegistry.h instead.

llvm-svn: 63937

llvm-svn: 63139

CreateVirtualRegisters does trivial copy coalescing. If a node def is used by a single CopyToReg, it reuses the virtual register assigned to the CopyToReg. This won't work for SDNode that is a clone or is itself cloned. Disable this optimization for those nodes or it can end up with non-SSA machine instructions.

llvm-svn: 62356

to support MachineInstr-based scheduling in addition to
SDNode-based scheduling.

llvm-svn: 62284

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

llvm-svn: 62015

instructions to avoid copies, because TwoAddressInstructionPass
also does this optimization.  The scheduler's version didn't
account for live-out values, which resulted in spurious commutes
and missed opportunities.

Now, TwoAddressInstructionPass handles all the opportunities,
instead of just those that the scheduler missed. The result is
usually the same, though there are occasional trivial differences
resulting from the avoidance of spurious commutes.

llvm-svn: 61611

there's nothing in the vector. Pacify them.

llvm-svn: 61536

code in ScheduleDAGSDNodes' BuildSchedGraph into separate functions.

llvm-svn: 61376

comment for the ScheduleDAGSDNodes class.

llvm-svn: 61341

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

simplify header dependencies for front-ends that just want to choose
a scheduler and don't need all the scheduling machinery declarations.

llvm-svn: 59978

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