When using AA to break false chain dependencies, we need to track multiple
stores per object in ScheduleDAGInstrs. Historically, we tracked potential alias
chains at the object level, and so all loads of an object would retain
dependencies on any store to that object. With AA, however, this is not
sufficient: non-overlapping stores and loads to the same object all need to be
tested for dependencies separately, we cannot only test all loads to an object
against only the last store (see PR18497 for an explicit example).
To mitigate any unwelcome compile-time impact when not using AA, only one store
is kept in the list per object when not using AA.
This, along with a stack coloring change to come shortly, will provide a test
case, fix PR18497 (and allow LLVM to compile itself using -enable-aa-sched-mi
on x86-64).
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@199657 91177308-0d34-0410-b5e6-96231b3b80d8
MIsNeedChainEdge, which is used by -enable-aa-sched-mi (AA in misched), had an
llvm_unreachable when -enable-aa-sched-mi is enabled and we reach an
instruction with multiple MMOs. Instead, return a conservative answer. This
allows testing -enable-aa-sched-mi on x86.
Also, this moves the check above the isUnsafeMemoryObject checks.
isUnsafeMemoryObject is currently correct only for instructions with one MMO
(as noted in the comment in isUnsafeMemoryObject):
// We purposefully do no check for hasOneMemOperand() here
// in hope to trigger an assert downstream in order to
// finish implementation.
The problem with this is that, had the candidate edge passed the
"!MIa->mayStore() && !MIb->mayStore()" check, the hoped-for assert would never
happen (which could, in theory, lead to incorrect behavior if one of these
secondary MMOs was volatile, for example).
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@198795 91177308-0d34-0410-b5e6-96231b3b80d8
This allows a target to use MI-Sched as an in-order scheduler that
will model strict resource conflicts without defining a processor
itinerary. Instead, the target can now use the new per-operand machine
model and define in-order resources with BufferSize=0. For example,
this would allow restricting the type of operations that can be formed
into a dispatch group. (Normally NumMicroOps is sufficient to enforce
dispatch groups).
If the intent is to model latency in in-order pipeline, as opposed to
resource conflicts, then a resource with BufferSize=1 should be
defined instead.
This feature is only casually tested as there are no in-tree targets
using it yet. However, Hal will be experimenting with POWER7.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@196517 91177308-0d34-0410-b5e6-96231b3b80d8
This patch tries to avoid unrelated changes other than fixing a few
hyphen-related ambiguities and contractions in nearby lines.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@196471 91177308-0d34-0410-b5e6-96231b3b80d8
This makes the API a bit more natural to use and makes it easier to make
LiveRanges implementation details private.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@192394 91177308-0d34-0410-b5e6-96231b3b80d8
This removes all expensive pressure tracking logic from the scheduling
critical path of node comparison.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@189643 91177308-0d34-0410-b5e6-96231b3b80d8
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.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@189640 91177308-0d34-0410-b5e6-96231b3b80d8
There are several optional (off-by-default) features in CodeGen that can make
use of alias analysis. These features are important for generating code for
some kinds of cores (for example the (in-order) PPC A2 core). This adds a
useAA() function to TargetSubtargetInfo to allow these features to be enabled
by default on a per-subtarget basis.
Here is the first use of this function: To control the default of the
-enable-aa-sched-mi feature.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@189563 91177308-0d34-0410-b5e6-96231b3b80d8
Estimate the cyclic critical path within a single block loop. If the
acyclic critical path is longer, then the loop will exhaust OOO
resources after some number of iterations. If lag between the acyclic
critical path and cyclic critical path is longer the the time it takes
to issue those loop iterations, then aggressively schedule for
latency.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@189120 91177308-0d34-0410-b5e6-96231b3b80d8
This will be used to compute the cyclic critical path and to
update precomputed per-node pressure differences.
In the longer term, it could also be used to speed up LiveInterval
update by avoiding visiting all global vreg users.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@189118 91177308-0d34-0410-b5e6-96231b3b80d8
This fixes a pathological compile time problem with very large blocks
and lots of scheduling boundaries.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@189116 91177308-0d34-0410-b5e6-96231b3b80d8
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.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@184032 91177308-0d34-0410-b5e6-96231b3b80d8
The register allocator expects minimal physreg live ranges. Schedule
physreg copies accordingly. This is slightly tricky when they occur in
the middle of the scheduling region. For now, this is handled by
rescheduling the copy when its associated instruction is
scheduled. Eventually we may instead bundle them, but only if we can
preserve the bundles as parallel copies during regalloc.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@179449 91177308-0d34-0410-b5e6-96231b3b80d8
MI sched DAG construction allows targets to include terminators into scheduling DAG.
Extend this functionality to labels as well.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@174977 91177308-0d34-0410-b5e6-96231b3b80d8
Maintain separate per-node and per-tree book-keeping.
Track all instructions above a DAG node including nested subtrees.
Seperately track instructions within a subtree.
Record subtree parents.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@173426 91177308-0d34-0410-b5e6-96231b3b80d8
Allow the strategy to select SchedDFS. Allow the results of SchedDFS
to affect initialization of the scheduler state.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@173425 91177308-0d34-0410-b5e6-96231b3b80d8
This is mostly refactoring, along with adding an instruction count
within the subtrees and ensuring we only look at data edges.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@173420 91177308-0d34-0410-b5e6-96231b3b80d8
For sanity, create a root when NumDataSuccs >= 4. Splitting large
subtrees will no longer be detrimental after my next checkin to handle
nested tree. A magic number of 4 is fine because single subtrees
seldom rejoin more than this. It makes subtrees easier to visualize
and heuristics more sane.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@173399 91177308-0d34-0410-b5e6-96231b3b80d8
A SparseMultiSet adds multiset behavior to SparseSet, while retaining SparseSet's desirable properties. Essentially, SparseMultiSet provides multiset behavior by storing its dense data in doubly linked lists that are inlined into the dense vector. This allows it to provide good data locality as well as vector-like constant-time clear() and fast constant time find(), insert(), and erase(). It also allows SparseMultiSet to have a builtin recycler rather than keeping SparseSet's behavior of always swapping upon removal, which allows it to preserve more iterators. It's often a better alternative to a SparseSet of a growable container or vector-of-vector.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@173064 91177308-0d34-0410-b5e6-96231b3b80d8
into their new header subdirectory: include/llvm/IR. This matches the
directory structure of lib, and begins to correct a long standing point
of file layout clutter in LLVM.
There are still more header files to move here, but I wanted to handle
them in separate commits to make tracking what files make sense at each
layer easier.
The only really questionable files here are the target intrinsic
tablegen files. But that's a battle I'd rather not fight today.
I've updated both CMake and Makefile build systems (I think, and my
tests think, but I may have missed something).
I've also re-sorted the includes throughout the project. I'll be
committing updates to Clang, DragonEgg, and Polly momentarily.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@171366 91177308-0d34-0410-b5e6-96231b3b80d8
misched used GetUnderlyingObject in order to break false load/store
dependencies, and the -enable-aa-sched-mi feature similarly relied on
GetUnderlyingObject in order to ensure it is safe to use the aliasing analysis.
Unfortunately, GetUnderlyingObject does not recurse through phi nodes, and so
(especially due to LSR) all of these mechanisms failed for
induction-variable-dependent loads and stores inside loops.
This change replaces uses of GetUnderlyingObject with GetUnderlyingObjects
(which will recurse through phi and select instructions) in misched.
Andy reviewed, tested and simplified this patch; Thanks!
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@169744 91177308-0d34-0410-b5e6-96231b3b80d8
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. =]
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@169131 91177308-0d34-0410-b5e6-96231b3b80d8
This is a simple, cheap infrastructure for analyzing the shape of a
DAG. It recognizes uniform DAGs that take the shape of bottom-up
subtrees, such as the included matrix multiplication example. This is
useful for heuristics that balance register pressure with ILP. Two
canonical expressions of the heuristic are implemented in scheduling
modes: -misched-ilpmin and -misched-ilpmax.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@168773 91177308-0d34-0410-b5e6-96231b3b80d8
This fixes a hole in the "cheap" alias analysis logic implemented within
the DAG builder itself, regardless of whether proper alias analysis is
enabled. It now handles this pattern produced by LSR+CodeGenPrepare.
%sunkaddr1 = ptrtoint * %obj to i64
%sunkaddr2 = add i64 %sunkaddr1, %lsr.iv
%sunkaddr3 = inttoptr i64 %sunkaddr2 to i32*
store i32 %v, i32* %sunkaddr3
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@168768 91177308-0d34-0410-b5e6-96231b3b80d8
Similarly to several recent fixes throughout the code replace std::map use with the MapVector.
Add find() method to the MapVector.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@168051 91177308-0d34-0410-b5e6-96231b3b80d8
This adds support for weak DAG edges to the general scheduling
infrastructure in preparation for MachineScheduler support for
heuristics based on weak edges.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@167738 91177308-0d34-0410-b5e6-96231b3b80d8
the MachineInstr MayLoad/MayLoad flags are based on the tablegen implementation.
For inline assembly, however, we need to compute these based on the constraints.
Revert r166929 as this is no longer needed, but leave the test case in place.
rdar://12033048 and PR13504
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@167040 91177308-0d34-0410-b5e6-96231b3b80d8
incorrect instruction sequence due to it not being aware that an
inline assembly instruction may reference memory.
This patch fixes the problem by causing the scheduler to always assume that any
inline assembly code instruction could access memory. This is necessary because
the internal representation of the inline instruction does not include
any information about memory accesses.
This should fix PR13504.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@166929 91177308-0d34-0410-b5e6-96231b3b80d8
Allows the new machine model to be used for NumMicroOps and OutputLatency.
Allows the HazardRecognizer to be disabled along with itineraries.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@165603 91177308-0d34-0410-b5e6-96231b3b80d8
This wasn't contributing anything significant to postRA heuristics except compile time (by my measurements) and will be replaced by a more general heuristic for cross-region dependencies within the scheduler itself.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@165563 91177308-0d34-0410-b5e6-96231b3b80d8
