The index stored in the RegDefIter is one after the current index.  When getting the index, decrement it so that it points to the current element.  Fixes an off-by-one bug encountered when trying to make use of MVT::untyped.

llvm-svn: 133923

Add a new MVT::untyped.  This will be used in future work for modelling ISA features like register pairs and lists with "interesting" constraints (such as ARM NEON contiguous register lists or even-odd paired registers).  We need to be able to generate these instructions (often from intrinsics), but don't want to have to assign a legal type to them.  Instead, we'll use an "untyped" edge to bypass the type-checking and simply ensure that the register classes match.

llvm-svn: 133106

induction variable. The preRA scheduler is unaware of induction vars,
so we look for potential "virtual register cycles" instead.

Fixes <rdar://problem/8946719> Bad scheduling prevents coalescing

llvm-svn: 129100

precisely track pressure on a selection DAG, but we can at least keep
it balanced. This design accounts for various interesting aspects of
selection DAGS: register and subregister copies, glued nodes, dead
nodes, unused registers, etc.

Added SUnit::NumRegDefsLeft and ScheduleDAGSDNodes::RegDefIter.

Note: I disabled PrescheduleNodesWithMultipleUses when register
pressure is enabled, based on no evidence other than I don't think it
makes sense to have both enabled.

llvm-svn: 124853

something that just glues two nodes together, even if it is
sometimes used for flags.

llvm-svn: 122310

take multiple cycles to decode.
For the current if-converter clients (actually only ARM), the instructions that
are predicated on false are not nops. They would still take machine cycles to
decode. Micro-coded instructions such as LDM / STM can potentially take multiple
cycles to decode. If-converter should take treat them as non-micro-coded
simple instructions.

llvm-svn: 113570

llvm-svn: 105775

Allow targets more controls on what nodes are scheduled by reg pressure, what for latency in hybrid mode.

llvm-svn: 104293

pipeline stall. It's useful for targets like ARM cortex-a8. NEON has a lot
of long latency instructions so a strict register pressure reduction
scheduler does not work well.
Early experiments show this speeds up some NEON loops by over 30%.

llvm-svn: 104216

changes before doing phi lowering for switches.

llvm-svn: 102809

1. Introduce some enums and accessors in the InlineAsm class
   that eliminate a ton of magic numbers when handling inline
   asm SDNode.
2. Add a new MDNodeSDNode selection dag node type that holds
   a MDNode (shocking!)
3. Add a new argument to ISD::INLINEASM nodes that hold !srcloc
   metadata, propagating it to the instruction emitter, which
   drops it.

No functionality change.

llvm-svn: 100605

Teach pre-regalloc scheduler to schedule loads from nearby addresses. It may improve cache locality. This is controlled by -cluster-loads for now.

llvm-svn: 94148

llvm-svn: 85556

into MachineInstrs. This is mostly just moving the code from
ScheduleDAGSDNodesEmit.cpp into a new class. This decouples MachineInstr
emitting from scheduling.

llvm-svn: 83699

it isn't needed in the ScheduleDAGSDNodes schedulers.

llvm-svn: 83691

 - Allocate MachineMemOperands and MachineMemOperand lists in MachineFunctions.
   This eliminates MachineInstr's std::list member and allows the data to be
   created by isel and live for the remainder of codegen, avoiding a lot of
   copying and unnecessary translation. This also shrinks MemSDNode.
 - Delete MemOperandSDNode. Introduce MachineSDNode which has dedicated
   fields for MachineMemOperands.
 - Change MemSDNode to have a MachineMemOperand member instead of its own
   fields with the same information. This introduces some redundancy, but
   it's more consistent with what MachineInstr will eventually want.
 - Ignore alignment when searching for redundant loads for CSE, but remember
   the greatest alignment.

Target-specific code which previously used MemOperandSDNodes with generic
SDNodes now use MemIntrinsicSDNodes, with opcodes in a designated range
so that the SelectionDAG framework knows that MachineMemOperand information
is available.

llvm-svn: 82794

Enhance EmitInstrWithCustomInserter() so target can specify CFG changes that sdisel will use to properly complete phi nodes.
Not functionality change yet.

llvm-svn: 82273

it accordingly. Thanks to Jakob Stoklund Olesen for pointing
out how this might be useful.

llvm-svn: 68986

This will be used to replace things like X86's MOV32to32_.

Enhance ScheduleDAGSDNodesEmit to be more flexible and robust
in the presense of subregister superclasses and subclasses. It
can now cope with the definition of a virtual register being in
a subclass of a use.

Re-introduce the code for recording register superreg classes and
subreg classes. This is needed because when subreg extracts and
inserts get coalesced away, the virtual registers are left in
the correct subclass.

llvm-svn: 68961

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