In particular, if the successor block, which is about to get a new
predecessor block, currently only has a single predecessor,
then the bonus instructions will be directly used within said successor,
which is fine, since the block with bonus instructions dominates that
successor. But once there's a new predecessor, the IR is no longer valid,
and we don't fix it, because we only update PHI nodes.
Which means, the live-out bonus instructions must be exclusively used
by the PHI nodes in successor blocks. So we have to form trivial PHI nodes.
which will then be successfully updated to recieve cloned bonus instns.
This all works fine, except for the fact that we don't have access to
the dominator tree, and we don't ignore unreachable code,
so we sometimes do end up having to deal with some weird IR.
Fixes https://bugs.llvm.org/show_bug.cgi?id=48450
Some of the pattern matching in PPCInstrVSX.td and node lowering involving vectors assumes 64bit mode. This patch disables some of the unsafe pattern matching and lowering of BUILD_VECTOR in 32bit mode.
Reviewed By: Xiangling_L
Differential Revision: https://reviews.llvm.org/D92789
CVP currently handles switches by checking an equality predicate
on all edges from predecessor blocks. Of course, this can only
work if the value being switched over is defined in a different block.
Replace this implementation with a call to getPredicateAt(), which
also does the predecessor edge predicate check (if not defined in
the same block), but can also do quite a bit more: It can reason
about phi-nodes by checking edge predicates for incoming values,
it can reason about assumes, and it can reason about block values.
As such, this makes the implementation both simpler and more
powerful. The compile-time impact on CTMark is in the noise.
These cover cases handled by getPredicateAt(), but not by the
current implementation:
* Assumes based on context instruction.
* Value from phi node in same block (using per-pred reasoning).
* Value from non-phi node in same block (using block-val reasoning).
The getPayload/getMask/getPassThrough functions should return values
that could be composed into a masked load/store without any additional
type casts. The previous fix violated that.
Instead, convert scalar mask to a vector right before rescaling.
- Document which processors are supported by which runtimes.
- Add missing mappings for code object V2 note records
Differential Revision: https://reviews.llvm.org/D93016
The last use of isLoop was removed on Apr 29, 2002 in commit
09bbb5c015c6e40b3d45da057f955ddb7c8f8485 as part of an effort to
remove "old induction varaible cannonicalization pass built on top of
interval analysis".
AlignVectors treats all loaded/stored values as vectors of bytes,
and masks as corresponding vectors of booleans, so make getMask
produce a 1-element vector for scalars from the start.
This makes it possible to use update_llc_test_checks to manage tests
that check for incorrect x86 stack offsets. It does not yet modify any
test to make use of this new option.
The ABI demands a data16 prefix for lea in 64-bit LP64 mode, but not in
64-bit ILP32 mode. In both modes this prefix would ordinarily be
ignored, but the instructions may be changed by the linker to
instructions that are affected by the prefix.
Reviewed By: RKSimon
Differential Revision: https://reviews.llvm.org/D93157
This adds some basic MVE masked load/store costs, notably changing the
cost of legal loads/stores to the MVECostFactor and the cost of
scalarized instructions to 8*NumElts.
Differential Revision: https://reviews.llvm.org/D86538
When it comes to the scalar cost of any predicated block, the loop
vectorizer by default regards this predication as a sign that it is
looking at an if-conversion and divides the scalar cost of the block by
2, assuming it would only be executed half the time. This however makes
no sense if the predication has been introduced to tail predicate the
loop.
Original patch by Anna Welker
Differential Revision: https://reviews.llvm.org/D86452
This introduces more flexible multiclass for declaring two flags controlling the same boolean keypath.
Compared to existing Opt{In,Out}FFlag multiclasses, the new syntax makes it easier to read option declarations and reason about the keypath.
This also makes specifying common properties of both flags possible.
I'm open to suggestions on the class names. Not 100% sure the benefits are worth the added complexity.
Depends on D92774.
Reviewed By: dexonsmith
Differential Revision: https://reviews.llvm.org/D92775
We don't need to always generate `-f[no-]experimental-new-pass-manager`.
This patch does not change the behavior of any other command line flag. (For example `-triple` is still being always generated.)
Reviewed By: dexonsmith, Bigcheese
Differential Revision: https://reviews.llvm.org/D92857
gcov computes the line execution count as the sum of (a) counts from
predecessors on other lines and (b) the sum of loop execution counts of blocks
on the same line (think of loops on one line).
For (b), we use Donald B. Johnson's cycle enumeration algorithm and perform
cycle cancelling for each cycle. This number of candidate cycles were
exponential and D93036 made it polynomial by skipping zero count cycles. The
time complexity is high (O(V*E^2) (it could be O(E^2) but the linear `Blocks`
check made it higher) and the implementation is complex.
We could just identify loops and sum all back edges. However, this requires a
dominator tree construction which is more complex. The time complexity can be
decreased to almost linear, though.
This patch just performs cycle cancelling iteratively. Add two members
`traversable` and `incoming` to GCOVArc. There are 3 states:
* `!traversable`: blocks not on this line or explored blocks
* `traversable && incoming == nullptr`: unexplored blocks
* `traversable && incoming != nullptr`: blocks which are being explored (on the stack)
If an arc points to a block being explored, a cycle has been found.
Let E be the number of arcs. Every time a cycle is found, at least one arc is
saturated (`edgeCount` reduced to 0), so there are at most E cycles. Finding one
cycle takes O(E) time, so the overall time complexity is O(E^2). Note that we
always augment through a back edge and never need to augment its reverse edge so
reverse edges in traditional flow networks are not needed.
Reviewed By: xinhaoyuan
Differential Revision: https://reviews.llvm.org/D93073
The performance improvement on LBM previously achieved with improved software
prefetching (36d4421) have gone lost recently with e00f189. There now is one
memory access in the loop that LoopDataPrefetch cannot handle (while before
there was none) which the heuristic rejects.
This patch adds a small margin by allowing 1 non-prefetched memory access for
every 32 prefetched ones, so that the heuristic doesn't bail in this type of
case.
Review: Ulrich Weigand
Differential Revision: https://reviews.llvm.org/D92985
Summary:
"Speculative fix for link failure on bots" with a mention of "the clang-ppc64le-rhel bot fails on link: http://lab.llvm.org:8011/#/builders/57/builds/2307/steps/6/logs/stdio".
PPCAsmPrinter.cpp:(.text._ZN12_GLOBAL__N_116PPCAIXAsmPrinter19emitFunctionBodyEndEv+0x2f8): undefined reference to `llvm::XCOFF::getNameForTracebackTableLanguageId(llvm::XCOFF::TracebackTable::LanguageID)'
PPCAsmPrinter.cpp:(.text._ZN12_GLOBAL__N_116PPCAIXAsmPrinter19emitFunctionBodyEndEv+0x2170): undefined reference to `llvm::XCOFF::parseParmsType(unsigned int, unsigned int)'
SUMMARY:
1. added a new option -xcoff-traceback-table to control whether generate traceback table for function.
2. implement the functionality of emit traceback table of a function.
Reviewers: hubert.reinterpretcast, Jason Liu
Differential Revision: https://reviews.llvm.org/D92398
This transform was added at:
c63799fc52ff
From what I see, it's the first demanded elements transform that adds
a new instruction using the IRBuilder. There are similar folds in
the generic demanded bits chunk of instcombine that also use the
InsertPointGuard code pattern.
The tests here would assert/crash because the new instruction was
being added at the start of the demanded elements analysis rather
than at the instruction that is being replaced.
This migrates all LLVM (except Kaleidoscope and
CodeGen/StackProtector.cpp) DebugLoc::get to DILocation::get.
The CodeGen/StackProtector.cpp usage may have a nullptr Scope
and can trigger an assertion failure, so I don't migrate it.
Reviewed By: #debug-info, dblaikie
Differential Revision: https://reviews.llvm.org/D93087
This patch adds support for lowering function calls with the
rv_marker attribute. The goal is to expand such calls to the
following sequence of instructions:
BL @fn
mov x29, x29
This sequence of instructions triggers Objective-C runtime optimizations,
hence we want to ensure no instructions get moved in between them.
This patch achieves that by adding a new CALL_RVMARKER ISD node,
which gets turned into the BLR_RVMARKER pseudo, which eventually gets
expanded into the sequence mentioned above. The sequence is then marked
as instruction bundle, to avoid anything being moved in between.
@ahatanak is working on using this attribute in the front- & middle-end.
Together with the front- & middle-end changes, this should address
PR31925 for AArch64.
Reviewed By: t.p.northover
Differential Revision: https://reviews.llvm.org/D92569
Add simple pass for removing redundant vsetvli instructions within a basic block. This handles the case where the AVL register and VTYPE immediate are the same and no other instructions that change VTYPE or VL are between them.
There are going to be more opportunities for improvement in this space as we development more complex tests.
Differential Revision: https://reviews.llvm.org/D92679
If we have two unknown sizes and one GEP operand and one non-GEP
operand, then we currently simply return MayAlias. The comment says
we can't do anything useful ... but we can! We can still check that
the underlying objects are different (and do so for the GEP-GEP case).
To reduce the compile-time impact, this a) checks this early, before
doing the relatively expensive GEP decomposition that will not be
used and b) doesn't do the check if the other operand is a phi or
select. In that case, the phi/select will already recurse, so this
would just do two slightly different recursive walks that arrive at
the same roots.
Compile-time is still a bit of a mixed bag: https://llvm-compile-time-tracker.com/compare.php?from=624af932a808b363a888139beca49f57313d9a3b&to=845356e14adbe651a553ed11318ddb5e79a24bcd&stat=instructions
On average this is a small improvement, but sqlite with ThinLTO has
a 0.5% regression (lencod has a 1% improvement).
The BasicAA test case checks this by using two memsets with unknown
size. However, the more interesting case where this is useful is
the LoopVectorize test case, as analysis of accesses in loops tends
to always us unknown sizes.
Differential Revision: https://reviews.llvm.org/D92401
Addressing clang bootstrap under the dynamic linking mode running out of static
allocation of value profile nodes, reported in D81682.
Differential Revision: https://reviews.llvm.org/D92669
Extract some changes not directly related to tileLoops out of D92974:
* Refactor `createLoopSkeleton` out of `createCanonicalLoop`.
* Introduce `ComputeIP` parameter to the `createCanonicalLoop` overload inserts instructions to compute the trip count. Specifying the location is necessary to make these instructions appear before the outermost loop of a loop nest that is tiled.
* Introduce `Name` parameter to `createCanonicalLoop`. This can help better understanding the origin of values of basic blocks with many loops. The default value is "loop" instead of "for" which could be confused with the "for directive" (aka worksharing-loop) and does not apply to Fortran.
* Remove `CanonicalLoopInfo::eraseFromParent` which is currently unused and untested and was added in anticipation to be used by `tileLoops`. `eraseFromParent` has shown to be insufficient when more than a single loop is involved and is replaced by `removeUnusedBlocksFromParent` in D92974.
Reviewed By: SouraVX
Differential Revision: https://reviews.llvm.org/D93088
