Failed for some reason, potentially because of the inner type
declaration in combination with the `using`. This might help.
Failure:
https://lab.llvm.org/buildbot/#/builders/127/builds/15432
(cherry picked from commit fc32a5c87d9d5aef2c0b27715153fdd45cebd3f3)
PHI nodes are not pass through but change their value, we have to
account for that to avoid missing stores.
Follow up for D107798 to fix PR51249 for good.
Differential Revision: https://reviews.llvm.org/D107808
(cherry picked from commit e7e3585cde0b08152a8cbf54029794d07c15963d)
This reapplies commit cbb709e25124dc38ee593882051fc88c987fe591 and
includes the use of the lookup method instead of operator[] to avoid
accidentally setting (empty) simplification callbacks.
This reverts commit aa27430a625b2fd059707a87f8ba2df8f480ff11.
AAValueSimplify, AAValueConstantRange, and AAPotentialValues all look at
the IR by default. If queried for a IR position which has a
simplification callback we should either look at the callback return, or
give up. We do the latter for now.
When we simplify at least one operand in the Attributor simplification
we can use the InstSimplify to work on the simplified operands. This
allows us to avoid duplication of the logic.
Depends on D106189
Differential Revision: https://reviews.llvm.org/D106190
D106185 allows us to determine if a store is needed easily. Using that
knowledge we can start to delete dead stores.
In AAIsDead we now track more state as an instruction can be dead (= the
old optimisitc state) or just "removable". A store instruction can be
removable while being very much alive, e.g., if it stores a constant
into an alloca or internal global. If we would pretend it was dead
instead of only removablewe we would ignore it when we determine what
values a load can see, so that is not what we want.
Differential Revision: https://reviews.llvm.org/D106188
This patch introduces `getPotentialCopiesOfStoredValue` which uses
AAPointerInfo to determine all "aliases" or "potential copies" of a
value that is stored into memory. This operation can fail but if it
succeeds it means we can visit all "uses" of a value even if it is
temporarily stored in memory.
There are two users for the function:
1) `Attributor::checkForAllUses` which will now ignore the value use
in a store if all "potential copies" can be identified and instead
be visited. This allows various AAs, including AAPointerInfo
itself, to look through memory.
2) `AANoCapture` which uses a custom use tracking through the
CaptureTracker interface and therefore needs to be thought
explicitly.
Differential Revision: https://reviews.llvm.org/D106185
This caused us to rerun AAMemoryBehaviorFloating::updateImpl over and
over again. Unfortunately it turned out to be hard to reproduce the
behavior in a reasonable way.
If we add a new live edge we need to indicate a change or otherwise the
new live block is not shown to users. Similarly, new known dead ends and
a changed `ToBeExploredFrom` set need to cause us to return CHANGED.
This patch introduces a pass that uses the Attributor to deduce AMDGPU specific attributes.
Reviewed By: jdoerfert, arsenm
Differential Revision: https://reviews.llvm.org/D104997
A simplification callback can mean that the IR value is modified beyond
the apparent IR semantics. That is, a `i1 true` could be replaced by an
`i1 false` based on high-level domain-specific information. If a user
provides a simplification callback we will not look at the IR but
instead give up if the callback returns a nullptr.
SPMDization D102307 detects incompatible OpenMP runtime calls to abort converting a target region to SPMD mode. Calls to memory allocation/de-allocation routines kmpc_alloc_shared, kmpc_free_shared are incompatible unless they are removed by AAHeapToStack/AAHeapToShared analysis. This patch extends SPMDization detection to include AAHeapToStack/AAHeapToShared analysis results for enlarging the scope of possible SPMDized regions detected.
Reviewed By: jdoerfert
Differential Revision: https://reviews.llvm.org/D105634
If we have a recursive function we could create multiple instantiations
of an SSA value, one per recursive invocation of the function. This is a
problem as we use SSA value equality in various places. The basic idea
follows from this test:
```
static int r(int c, int *a) {
int X;
return c ? r(false, &X) : a == &X;
}
int test(int c) {
return r(c, undef);
}
```
If we look through the argument `a` we will end up with `X`. Using SSA
value equality we will fold `a == &X` to true and return true even
though it should have been false because `a` and `&X` are from different
instantiations of the function.
Various tests for this have been placed in value-simplify-instances.ll
and this commit fixes them all by avoiding to produce simplified values
that could be non-unique at runtime. Thus, the result of a simplify
value call will always be unique at runtime or the original value, both
do not allow to accidentally compare two instances of a value with each
other and conclude they are equal statically (pointer equivalence) while
they are unequal at runtime.
There is no need for a non-const argument interface and the const argument modification covers existing and upcoming use cases.
Reviewed By: jdoerfert
Differential Revision: https://reviews.llvm.org/D106418
AAMemoryBehaviorFloating used a custom use tracking mechanism even
though checkForAllUses exists and is already more powerful. Further,
AAMemoryBehaviorFloating uses AANoCapture to guarantee that there are no
aliases and following the uses is sufficient. This is an OK assumption
if checkForAllUses is used but custom tracking is easily out of sync
with AANoCapture and problems follow.
As with other patches before, the simplification callback interface
requires us to go through the Attributor::getAssumedSimplified API first
before we recurs.
It is unclear if the problem can be explicitly tested with our current
infrastructure.
We first simplify the operands of a compare and then reason on the
simplified versions, e.g., with AANonNull.
This does improve the simplification capabilities but also fixes a
potential problem that has not yet been observed by simplifying the
operands first.
A byval argument is a different value in the caller and callee, we
cannot propagate the information as part of AAValueSimplify. Users that
want to deal with byval arguments need to specifically perform the
argument -> call site step. We do not do this for now.
This patch introduces AAPointerInfo which tracks the uses of a pointer
and places them in "bins" based on their offset from the base and access
size.
As with other AAs, any pointer can be tracked but it is up to the user
to make sense of the results. The user in this patch is AAValueSimplify
and AAPotentialValues which both utilize AAPointerInfo to determine the
value of a load. For now, this is restricted to loads of allocas and
internal globals. Through the use of AAPointerInfo and the "bins" we can
track struct members separately. The users also know that storing only
zeros (at unknown indices) will result in loading only 0 (from unknown
indices). Other than that, the users are flow and context insensitive
(for now).
To deal with the "bins" more easily, AAPointerInfo provides a
forallInterfearingAccesses that applies a callback on all accesses
that might interfere with a given load or store.
Differential Revision: https://reviews.llvm.org/D104432
As a first step to simplify loads we only handle `null` and `undef`
underlying objects, as well as objects that have the load as a single user.
Loads of those values can be replaced by the initializer, if any.
Proper reasoning is introduced in a follow up patch
Differential Revision: https://reviews.llvm.org/D103862
This patch adds unique idenfitiers to the existing OpenMP remarks. This makes
it easier to identify the corresponding documentation for each remark that will
be hosted in the OpenMP webpage.
Depends on D105898
Reviewed By: jdoerfert
Differential Revision: https://reviews.llvm.org/D105939
This patch rewrites and reworks a few of the existing remarks to make the mmore
concise and consistent prior to writing the documentation for them.
Reviewed By: jdoerfert
Differential Revision: https://reviews.llvm.org/D105898
This patch adds a feature to AACallEdges AbstractAttribute that allows
users to ask if there is a unknown callee that isn't a inline assembly.
This feature is needed by some of it's users.
Reviewed By: jdoerfert
Differential Revision: https://reviews.llvm.org/D105992
As with other Attributor interfaces we often want to know if assumed
information was used to answer a query. This is important if only
known information is allowed or if known information can lead to an
early fixpoint. The users have been adjusted but none of them utilizes
the new information yet.
AllocationInfo and DeallocationInfo objects themselves are allocated
with the Attributor bump allocator and do not need to be deallocated.
That said, the sets in AllocationInfo and DeallocationInfo need to be
destroyed to avoid memory leaks.
When we talk to outside analyse, e.g., LVI and ScalarEvolution, we need
to be careful with the query. The particular error occurred because we
folded a PHI node before the LVI query but the context location was now
not dominated by the value anymore. This is not supported by LVI so we
have to filter these situations before we query the outside analyses.
In order to simplify future extensions, e.g., the merge of
AAHeapToShared in to AAHeapToStack, we reorganize AAHeapToStack and the
state we keep for each malloc-like call. The result is also less
confusing as we only track malloc-like calls, not all calls. Further, we
only perform the updates necessary for a malloc-like to argue it can go
to the stack, e.g., we won't check all uses if we moved on to the
"must-be-freed" argument.
This patch also uses Attributor helps to simplify the allocated size,
alignment, and the potentially freed objects.
Overall, this is mostly a reorganization and only the use of the
optimistic helpers should change (=improve) the capabilities a bit.
Differential Revision: https://reviews.llvm.org/D104993
We have to be careful when we replace values to not use a non-dominating
instruction. It makes sense that simplification offers those as
"simplified values" but we can't manifest them in the IR without PHI
nodes. In the future we should consider potentially adding those PHI
nodes.
We should use AAValueSimplify for all value simplification, however
there was some leftover logic that predates AAValueSimplify in
AAReturnedValues. This remove the AAReturnedValues part and provides a
replacement by making AAValueSimplifyReturned strong enough to handle
all previously covered cases. Further, this improve
AAValueSimplifyCallSiteReturned to handle returned arguments.
AAReturnedValues is now much easier and the collected returned
values/instructions are now from the associated function only, making it
much more sane. We also do not have the brittle logic anymore that looks
for unresolved calls. Instead, we use AAValueSimplify to handle
recursion.
Useful code has been split into helper functions, e.g., an Attributor
interface to get a simplified value.
Differential Revision: https://reviews.llvm.org/D103860
As the `llvm::getUnderlyingObjects` helper, the optimistic version
collects objects that might be the base of a given pointer. In contrast
to the llvm variant, the optimistic one will use assumed information,
e.g., about select conditions or dead blocks, to provide a more precise
result.
Differential Revision: https://reviews.llvm.org/D103859
Not all attributes are able to handle the interprocedural step and
follow the uses into a call site. Let them be able to combine call site
uses instead. This might result in some unused values/arguments being
leftover but it removes problems where we misused "is dead" even though
it was actually "is simplified/replaced".
We explicitly check for dead values due to constant propagation in
`AAIsDeadValueImpl::areAllUsesAssumedDead` instead.
Differential Revision: https://reviews.llvm.org/D103858
Broke check-clang, see https://reviews.llvm.org/D102307#2869065
Ran `git revert -n ebbe149a6f08535ede848a531a601ae6591cfbc5..269416d41908bb670f67af689155d5ab8eea689a`
As with other Attributor interfaces we often want to know if assumed
information was used to answer a query. This is important if only
known information is allowed or if known information can lead to an
early fixpoint. The users have been adjusted but none of them utilizes
the new information yet.
When we talk to outside analyse, e.g., LVI and ScalarEvolution, we need
to be careful with the query. The particular error occurred because we
folded a PHI node before the LVI query but the context location was now
not dominated by the value anymore. This is not supported by LVI so we
have to filter these situations before we query the outside analyses.
We have to be careful when we replace values to not use a non-dominating
instruction. It makes sense that simplification offers those as
"simplified values" but we can't manifest them in the IR without PHI
nodes. In the future we should consider potentially adding those PHI
nodes.
In order to simplify future extensions, e.g., the merge of
AAHeapToShared in to AAHeapToStack, we reorganize AAHeapToStack and the
state we keep for each malloc-like call. The result is also less
confusing as we only track malloc-like calls, not all calls. Further, we
only perform the updates necessary for a malloc-like to argue it can go
to the stack, e.g., we won't check all uses if we moved on to the
"must-be-freed" argument.
This patch also uses Attributor helps to simplify the allocated size,
alignment, and the potentially freed objects.
Overall, this is mostly a reorganization and only the use of the
optimistic helpers should change (=improve) the capabilities a bit.
Differential Revision: https://reviews.llvm.org/D104993
We should use AAValueSimplify for all value simplification, however
there was some leftover logic that predates AAValueSimplify in
AAReturnedValues. This remove the AAReturnedValues part and provides a
replacement by making AAValueSimplifyReturned strong enough to handle
all previously covered cases. Further, this improve
AAValueSimplifyCallSiteReturned to handle returned arguments.
AAReturnedValues is now much easier and the collected returned
values/instructions are now from the associated function only, making it
much more sane. We also do not have the brittle logic anymore that looks
for unresolved calls. Instead, we use AAValueSimplify to handle
recursion.
Useful code has been split into helper functions, e.g., an Attributor
interface to get a simplified value.
Differential Revision: https://reviews.llvm.org/D103860
As the `llvm::getUnderlyingObjects` helper, the optimistic version
collects objects that might be the base of a given pointer. In contrast
to the llvm variant, the optimistic one will use assumed information,
e.g., about select conditions or dead blocks, to provide a more precise
result.
Differential Revision: https://reviews.llvm.org/D103859
Not all attributes are able to handle the interprocedural step and
follow the uses into a call site. Let them be able to combine call site
uses instead. This might result in some unused values/arguments being
leftover but it removes problems where we misused "is dead" even though
it was actually "is simplified/replaced".
We explicitly check for dead values due to constant propagation in
`AAIsDeadValueImpl::areAllUsesAssumedDead` instead.
Differential Revision: https://reviews.llvm.org/D103858
We often need to deal with the value lattice that contains none and
undef as special values. A simple helper makes this much nicer.
Differential Revision: https://reviews.llvm.org/D103857
