Schedule a load and its use in the same packet in MISched. Previously,
isResourceAvailable was returning false for dependences in the same
packet, which prevented MISched from packetizing a load and its use in
the same packet for v60.
Patch by Ikhlas Ajbar.
llvm-svn: 275804
The machine scheduler needs to account for available resources
more accurately in order to avoid scheduling an instruction that
forces a new packet to be created.
This occurs in two ways: First, an instruction without an available
resource may have a large priority due to other metrics and be
scheduled when there are other instructions with available resources.
Second, an instruction with a non-zero latency may become available
prematurely. In both these cases, we attempt change the priority
in order to allow a better instruction to be scheduled.
Patch by Brendon Cahoon.
llvm-svn: 275793
An instruction may have multiple predecessors that are candidates
for using .cur. However, only one of them can use .cur in the
packet. When this case occurs, we need to make sure that only
one of the dependences gets a 0 latency value.
Patch by Brendon Cahoon.
llvm-svn: 275790
The Hexagon schedulers need to handle instructions with a latency
of 0 or 2 more accurately. The problem, in v60, is that a dependence
between two instructions with a 2 cycle latency can use a .cur version
of the source to achieve a 0 cycle latency when the use is in the
same packet. Any othe use, must be at least 2 packets later, or a
stall occurs. In other words, the compiler does not want to schedule
the dependent instructions 1 cycle later.
To achieve this, the latency adjustment code allows only a single
dependence to have a zero latency. All other instructions have the
other value, which is typically 2 cycles. We use a heuristic to
determine which instruction gets the 0 latency.
The Hexagon machine scheduler was also changed to increase the cost
associated with 0 latency dependences than can be scheduled in the
same packet.
Patch by Brendon Cahoon.
llvm-svn: 275625
In all but one case, change the DFAPacketizer API to take MachineInstr&
instead of MachineInstr*. In DFAPacketizer::endPacket(), take
MachineBasicBlock::iterator. Besides cleaning up the API, this is in
search of PR26753.
llvm-svn: 262142
Both MachineLoopInfo and MachineDominatorTree may be null in ScheduleDAGMI
constructor call. It is undefined behavior to take references to these values.
This bug is reported by UBSan.
llvm-svn: 216118
The old system was fairly convoluted:
* A temporary label was created.
* A single PROLOG_LABEL was created with it.
* A few MCCFIInstructions were created with the same label.
The semantics were that the cfi instructions were mapped to the PROLOG_LABEL
via the temporary label. The output position was that of the PROLOG_LABEL.
The temporary label itself was used only for doing the mapping.
The new CFI_INSTRUCTION has a 1:1 mapping to MCCFIInstructions and points to
one by holding an index into the CFI instructions of this function.
I did consider removing MMI.getFrameInstructions completelly and having
CFI_INSTRUCTION own a MCCFIInstruction, but MCCFIInstructions have non
trivial constructors and destructors and are somewhat big, so the this setup
is probably better.
The net result is that we don't create temporary labels that are never used.
llvm-svn: 203204
Created SUPressureDiffs array to hold the per node PDiff computed during DAG building.
Added a getUpwardPressureDelta API that will soon replace the old
one. Compute PressureDelta here from the precomputed PressureDiffs.
Updating for liveness will come next.
llvm-svn: 189640
than once, and the second time through we leaked memory. Found thanks to
the vg-leak bot, but I can't locally reproduce it with valgrind. The
debugger confirms that it is in fact leaking here.
This whole code is totally gross. Why is initialize being called on each
runOnFunction??? Why aren't these OwningPtr<>s, and why aren't their
lifetimes better defined? Anyways, this is just a surgical change to
help out the leak checking bots.
llvm-svn: 187299
Replace the ill-defined MinLatency and ILPWindow properties with
with straightforward buffer sizes:
MCSchedMode::MicroOpBufferSize
MCProcResourceDesc::BufferSize
These can be used to more precisely model instruction execution if desired.
Disabled some misched tests temporarily. They'll be reenabled in a few commits.
llvm-svn: 184032
Sooooo many of these had incorrect or strange main module includes.
I have manually inspected all of these, and fixed the main module
include to be the nearest plausible thing I could find. If you own or
care about any of these source files, I encourage you to take some time
and check that these edits were sensible. I can't have broken anything
(I strictly added headers, and reordered them, never removed), but they
may not be the headers you'd really like to identify as containing the
API being implemented.
Many forward declarations and missing includes were added to a header
files to allow them to parse cleanly when included first. The main
module rule does in fact have its merits. =]
llvm-svn: 169131
Allows the new machine model to be used for NumMicroOps and OutputLatency.
Allows the HazardRecognizer to be disabled along with itineraries.
llvm-svn: 165603
This patch introduces a possibility for Hexagon MI scheduler
to perform some target specific post- processing on the scheduling
DAG prior to scheduling.
llvm-svn: 163903
The Hexagon target decided to use a lot of functionality from the
target-independent scheduler. That's fine, and other targets should be
able to do the same. This reorg and API update makes that easy.
For the record, ScheduleDAGMI was not meant to be subclassed. Instead,
new scheduling algorithms should be able to implement
MachineSchedStrategy and be done. But if need be, it's nice to be
able to extend ScheduleDAGMI, so I also made that easier. The target
scheduler is somewhat more apt to break that way though.
llvm-svn: 163580
Nirav Dave