This patch mechanically replaces None with std::nullopt where the
compiler would warn if None were deprecated. The intent is to reduce
the amount of manual work required in migrating from Optional to
std::optional.
This is part of an effort to migrate from llvm::Optional to
std::optional:
https://discourse.llvm.org/t/deprecating-llvm-optional-x-hasvalue-getvalue-getvalueor/63716
This restores commit b756096b0c, which was
originally reverted in 00b09a7b18.
AAPointerInfo now maintains a list of all Access objects that it owns, along
with the following maps:
- OffsetBins: OffsetAndSize -> { Access }
- InstTupleMap: RemoteI x LocalI -> Access
A RemoteI is any instruction that accesses memory. RemoteI is different from
LocalI if and only if LocalI is a call; then RemoteI is some instruction in the
callgraph starting from LocalI.
Motivation: When AAPointerInfo recomputes the offset for an instruction, it sets
the value to Unknown if the new offset is not the same as the old offset. The
instruction must now be moved from its current bin to the bin corresponding to
the new offset. This happens for example, when:
- A PHINode has operands that result in different offsets.
- The same remote inst is reachable from the same local inst via different paths
in the callgraph:
```
A (local inst)
|
B
/ \
C1 C2
\ /
D (remote inst)
```
This fixes a bug where a store is incorrectly eliminated in a lit test.
Reviewed By: jdoerfert, ye-luo
Differential Revision: https://reviews.llvm.org/D136526
AAPointerInfo now maintains a list of all Access objects that it owns, along
with the following maps:
- OffsetBins: OffsetAndSize -> { Access }
- InstTupleMap: RemoteI x LocalI -> Access
A RemoteI is any instruction that accesses memory. RemoteI is different from
LocalI if and only if LocalI is a call; then RemoteI is some instruction in the
callgraph starting from LocalI.
Motivation: When AAPointerInfo recomputes the offset for an instruction, it sets
the value to Unknown if the new offset is not the same as the old offset. The
instruction must now be moved from its current bin to the bin corresponding to
the new offset. This happens for example, when:
- A PHINode has operands that result in different offsets.
- The same remote inst is reachable from the same local inst via different paths
in the callgraph:
```
A (local inst)
|
B
/ \
C1 C2
\ /
D (remote inst)
```
This fixes a bug where a store is incorrectly eliminated in a lit test.
Reviewed By: jdoerfert
Differential Revision: https://reviews.llvm.org/D136526
The struct OffsetAndSize is a simple tuple of two int64_t. Treating it as a
derived class of std::pair has no special benefit, but it makes the code
verbose since we need get/set functions that avoid using "first" and "second" in
client code. Eliminating the std::pair makes this more readable.
Reviewed By: jdoerfert
Differential Revision: https://reviews.llvm.org/D136745
When determining the initial value of the object, use the constant
folding API to load a given type at a given offset in the global
initializer. This makes it work for cases where the load doesn't
directly correspond to an aggregate member.
Differential Revision: https://reviews.llvm.org/D135435
If we have a constant aggregate, e.g., as an initializer, we usually
failed to extract the proper value/type from it. This patch provides the
size and offset information necessary to extract the right part of the
constant.
Revert "[Attributor] Teach AAPointerInfo to look into aggregates"
This reverts commit 844f6c5d03 and
4ed0a88cd8 as they broke the buildbots
that run openmp/libomptarget/test/offloading/bug49021.cpp.
If we have a constant aggregate, e.g., as an initializer, we usually
failed to extract the proper value/type from it. This patch provides the
size and offset information necessary to extract the right part of the
constant.
If a function is non-recursive we only performed intra-procedural
reasoning for reachability (via AA::isPotentiallyReachable). However,
if it is re-entrant that doesn't mean we can't reach. Instead of this
problematic logic in the reachability reasoning we utilize logic in
AAPointerInfo. If a location is for sure written by a function it can
be re-entrant or recursive we know only intra-procedural reasoning is
sufficient.
If we have a dominating must-write access we do not need to know the
initial value of some object to perform reasoning about the potential
values. The dominating must-write has overwritten the initial value.
If we only have exact accesses we should never require the bit-pattern
to be uniform (in this case 0). Only a non-exact access should force us
to require only 0 values.
For the longest time we used `AAValueSimplify` and
`genericValueTraversal` to determine "potential values". This was
problematic for many reasons:
- We recomputed the result a lot as there was no caching for the 9
locations calling `genericValueTraversal`.
- We added the idea of "intra" vs. "inter" procedural simplification
only as an afterthought. `genericValueTraversal` did offer an option
but `AAValueSimplify` did not. Thus, we might end up with "too much"
simplification in certain situations and then gave up on it.
- Because `genericValueTraversal` was not a real `AA` we ended up with
problems like the infinite recursion bug (#54981) as well as code
duplication.
This patch introduces `AAPotentialValues` and replaces the
`AAValueSimplify` uses with it. `genericValueTraversal` is folded into
`AAPotentialValues` as are the instruction simplifications performed in
`AAValueSimplify` before. We further distinguish "intra" and "inter"
procedural simplification now.
`AAValueSimplify` was not deleted as we haven't ported the
re-materialization of instructions yet. There are other differences over
the former handling, e.g., we may not fold trivially foldable
instructions right now, e.g., `add i32 1, 1` is not folded to `i32 2`
but if an operand would be simplified to `i32 1` we would fold it still.
We are also even more aware of function/SCC boundaries in CGSCC passes,
which is good even if some tests look like they regress.
Fixes: https://github.com/llvm/llvm-project/issues/54981
Note: A previous version was flawed and consequently reverted in
6555558a80.
For the longest time we used `AAValueSimplify` and
`genericValueTraversal` to determine "potential values". This was
problematic for many reasons:
- We recomputed the result a lot as there was no caching for the 9
locations calling `genericValueTraversal`.
- We added the idea of "intra" vs. "inter" procedural simplification
only as an afterthought. `genericValueTraversal` did offer an option
but `AAValueSimplify` did not. Thus, we might end up with "too much"
simplification in certain situations and then gave up on it.
- Because `genericValueTraversal` was not a real `AA` we ended up with
problems like the infinite recursion bug (#54981) as well as code
duplication.
This patch introduces `AAPotentialValues` and replaces the
`AAValueSimplify` uses with it. `genericValueTraversal` is folded into
`AAPotentialValues` as are the instruction simplifications performed in
`AAValueSimplify` before. We further distinguish "intra" and "inter"
procedural simplification now.
`AAValueSimplify` was not deleted as we haven't ported the
re-materialization of instructions yet. There are other differences over
the former handling, e.g., we may not fold trivially foldable
instructions right now, e.g., `add i32 1, 1` is not folded to `i32 2`
but if an operand would be simplified to `i32 1` we would fold it still.
We are also even more aware of function/SCC boundaries in CGSCC passes,
which is good even if some tests look like they regress.
Fixes: https://github.com/llvm/llvm-project/issues/54981
Note: A previous version was flawed and consequently reverted in
6555558a80.
Drop the requirement that getInitialValueOfAllocation() must be
passed an allocator function, shifting the responsibility for
checking that into the function (which it does anyway). The
motivation is to avoid some calls to isAllocationFn(), which has
somewhat ill-defined semantics (given the number of
allocator-related attributes we have floating around...)
(For this function, all we eventually need is an allockind of
zeroed or uninitialized.)
Differential Revision: https://reviews.llvm.org/D127274
When determining liveness via Attributor::isAssumedDead(...) we might
end up without a liveness AA or with one pointing into another function.
Neither is helpful and we will avoid both from now on.
Reapplied after fixing the ASAN error which caused the revert:
db68a25ca9
For the longest time we used `AAValueSimplify` and
`genericValueTraversal` to determine "potential values". This was
problematic for many reasons:
- We recomputed the result a lot as there was no caching for the 9
locations calling `genericValueTraversal`.
- We added the idea of "intra" vs. "inter" procedural simplification
only as an afterthought. `genericValueTraversal` did offer an option
but `AAValueSimplify` did not. Thus, we might end up with "too much"
simplification in certain situations and then gave up on it.
- Because `genericValueTraversal` was not a real `AA` we ended up with
problems like the infinite recursion bug (#54981) as well as code
duplication.
This patch introduces `AAPotentialValues` and replaces the
`AAValueSimplify` uses with it. `genericValueTraversal` is folded into
`AAPotentialValues` as are the instruction simplifications performed in
`AAValueSimplify` before. We further distinguish "intra" and "inter"
procedural simplification now.
`AAValueSimplify` was not deleted as we haven't ported the
re-materialization of instructions yet. There are other differences over
the former handling, e.g., we may not fold trivially foldable
instructions right now, e.g., `add i32 1, 1` is not folded to `i32 2`
but if an operand would be simplified to `i32 1` we would fold it still.
We are also even more aware of function/SCC boundaries in CGSCC passes,
which is good.
Fixes: https://github.com/llvm/llvm-project/issues/54981
When determining liveness via Attributor::isAssumedDead(...) we might
end up without a liveness AA or with one pointing into another function.
Neither is helpful and we will avoid both from now on.
X86 codegen uses function attribute `min-legal-vector-width` to select the proper ABI. The intention of the attribute is to reflect user's requirement when they passing or returning vector arguments. So Clang front-end will iterate the vector arguments and set `min-legal-vector-width` to the width of the maximum for both caller and callee.
It is assumed any middle end optimizations won't care of the attribute expect inlining and argument promotion.
- For inlining, we will propagate the attribute of inlined functions because the inlining functions become the newer caller.
- For argument promotion, we check the `min-legal-vector-width` of the caller and callee and refuse to promote when they don't match.
The problem comes from the optimizations' combination, as shown by https://godbolt.org/z/zo3hba8xW. The caller `foo` has two callees `bar` and `baz`. When doing argument promotion, both `foo` and `bar` has the same `min-legal-vector-width`. So the argument was promoted to vector. Then the inlining inlines `baz` to `foo` and updates `min-legal-vector-width`, which results in ABI mismatch between `foo` and `bar`.
This patch fixes the problem by expanding the concept of `min-legal-vector-width` to indicator of functions arguments. That says, any passes touch functions arguments have to set `min-legal-vector-width` to the value reflects the width of vector arguments. It makes sense to me because any arguments modifications are ABI related and should response for the ABI compatibility.
Differential Revision: https://reviews.llvm.org/D123284
Instead of lengthy constructors we can now set the members of a
read-only struct before the Attributor is created. Should make it
clearer what is configurable and also help introducing new options in
the future. This actually added IsModulePass and avoids deduction
through the Function set size. No functional change was intended.
Kazu Hirata