[mlir][Tensor] Stop using `getAttrs()` and only copy discardable call attributes explicitly (#226412)
Preserve discardable metadata when recreating a typed direct call; its
builder supplies the inherent fields.
Part of #155475
Assisted-by: Codex
[LLD][ELF] Skip symbols to dead mergeable section pieces for --why-live (#226238)
Before this change, `--why-live=*` in "why-live.test" incorrectly prints
`live symbol: b.o:(dead)`.
[flang][NFC] Say which control successors are not incoming branches
The map records branches, not every control successor: a construct
transferring control between its own statements is not a branch
(F2023 11.2.1 p1), so the successors analyzeBranches sets directly are
absent from it. Say so, rather than calling the map a plain inverse.
[flang] Resolve an assigned GO TO's targets from the completed assign map
An assigned GO TO reaches any label ASSIGNed to its variable, and a label
list does not bound that: lowering allows a branch to any ASSIGNed label
whether or not the list names it. Branch analysis only sees the ASSIGNs
preceding the GO TO in program order, so the successors it records, and the
incoming branches derived from them, can be incomplete.
The symbol-to-labels map is complete once branch analysis has finished,
which is when the classification runs. Ask it for the full target set
instead of trusting the recorded successors, so a loop whose assigned GO TO
stays within its body is still recognised.
[flang] Record the evaluations that branch to each evaluation
The PFT records where each branch goes, but not where it comes from, so
asking whether anything branches into a construct means walking the whole
procedure.
Record the reverse edges beside the forward ones, and print them in PFT
dumps so both directions of the branch graph are visible.
[flang] Lower loops whose branching is confined to their body structurally
Such a loop was classified separately by a previous change but still
lowered as unstructured, so its structured form was lost.
Lower it structurally instead, with its body folded into a region that can
hold the branching. The loop keeps its bounds on the op, so it remains
available to whatever transforms or parallelizes it. Only the body is
folded: the loop control statements are emitted as they are for any
structured loop, since a branch from outside may target either of them.
Loops an OpenACC or OpenMP directive owns are lowered the same way, so
they keep their form too.
[flang] Honor the execute-region wrap flag when detecting loop internals
A loop whose branching is confined to its body is lowered with that body
in an scf.execute_region, since the CFG needs more than the single block
fir.do_loop's region admits. With the wrap disabled there is nowhere to
put those blocks, so skip the reclassification and leave the loop
unstructured.
[flang] Keep loops with a non-terminating body unstructured
A loop body that cannot run to completion must not be folded into an
scf.execute_region: the region carries no memory effects, so DCE deletes
it outright, dropping the non-termination and letting execution fall past
the loop. Branches survive that, being terminators.
An infinite DO was already rejected. Follow chains of unconditional GO TOs
as well and reject a body whose chain closes on itself, which is the same
bound the cf.br canonicalization applies to cyclic branches.
[flang] Detect loops whose branching is confined to their body
A DO loop is classified as either structured or unstructured, and a single
raw branch anywhere in its body forces the loop -- and every construct
enclosing it -- onto the unstructured path.
That is stronger than necessary. A loop keeps its structured control flow
as long as its branching neither leaves its body nor enters it from
outside. Classify such a loop separately from a fully unstructured one.
This only classifies: lowering is unchanged. PFT dumps mark the new
classification with '~', which is what the tests key on.
[flang][Test] Cover the lowering of loops with a non-terminating body
A previous change leaves such a loop unstructured. Check what that produces:
the cycle survives as a block branching to itself, no fir.do_loop is emitted
for the loop control, and a loop that only needs a block of its own still
gets the structured form with its body in a region.
[flang][Test] Cover the lowering of loops with a non-terminating body
A previous change leaves such a loop unstructured. Check what that produces:
the cycle survives as a block branching to itself, no fir.do_loop is emitted
for the loop control, and a loop that only needs a block of its own still
gets the structured form with its body in a region.
[flang] Keep loops with a non-terminating body unstructured
A loop body that cannot run to completion must not be folded into an
scf.execute_region: the region carries no memory effects, so DCE deletes
it outright, dropping the non-termination and letting execution fall past
the loop. Branches survive that, being terminators.
An infinite DO was already rejected. Follow chains of unconditional GO TOs
as well and reject a body whose chain closes on itself, which is the same
bound the cf.br canonicalization applies to cyclic branches.
[flang] Lower loops whose branching is confined to their body structurally
Such a loop was classified separately by a previous change but still
lowered as unstructured, so its structured form was lost.
Lower it structurally instead, with its body folded into a region that can
hold the branching. The loop keeps its bounds on the op, so it remains
available to whatever transforms or parallelizes it. Only the body is
folded: the loop control statements are emitted as they are for any
structured loop, since a branch from outside may target either of them.
Loops an OpenACC or OpenMP directive owns are lowered the same way, so
they keep their form too.
[flang] Honor the execute-region wrap flag when detecting loop internals
A loop whose branching is confined to its body is lowered with that body
in an scf.execute_region, since the CFG needs more than the single block
fir.do_loop's region admits. With the wrap disabled there is nowhere to
put those blocks, so skip the reclassification and leave the loop
unstructured.
[flang] Detect loops whose branching is confined to their body
A DO loop is classified as either structured or unstructured, and a single
raw branch anywhere in its body forces the loop -- and every construct
enclosing it -- onto the unstructured path.
That is stronger than necessary. A loop keeps its structured control flow
as long as its branching neither leaves its body nor enters it from
outside. Classify such a loop separately from a fully unstructured one.
This only classifies: lowering is unchanged. PFT dumps mark the new
classification with '~', which is what the tests key on.
[flang] Resolve an assigned GO TO's targets from the completed assign map
An assigned GO TO reaches any label ASSIGNed to its variable, and a label
list does not bound that: lowering allows a branch to any ASSIGNed label
whether or not the list names it. Branch analysis only sees the ASSIGNs
preceding the GO TO in program order, so the successors it records, and the
incoming branches derived from them, can be incomplete.
The symbol-to-labels map is complete once branch analysis has finished,
which is when the classification runs. Ask it for the full target set
instead of trusting the recorded successors, so a loop whose assigned GO TO
stays within its body is still recognised.
[DAG] SimplifyMultipleUseDemandedBits - simplify ISD::SCALAR_TO_VECTOR to ISD::POISON if we don't demand 0th element (#225530)
Equivalent fold to SimplifyDemandedBits/SimplifyDemandedVectorElts
Fixes a number of minor regressions from #217185
[AArch64][CostModel] Consider some nxv1 operations as legal
This is allowing some operations on vscale x 1 types, namely:
- load/store
- masked load/store
- arithmetic instructions like add/sub/mul
For those, there is already codegen coverage. See e.g.
- llvm/test/CodeGen/AArch64/sve-int-arith.ll
- llvm/test/CodeGen/AArch64/sve-load-store-legalisation.ll
- llvm/test/CodeGen/AArch64/sve-masked-gather.ll
- llvm/test/CodeGen/AArch64/sve-masked-scatter.ll
