[GlobalOpt] Don't evaluate large memset (PR62191)

If the memset is large, checking every single byte of the global
may be very slow. Add an upper bound on the size of memset we
handle.

For the comm

[GlobalOpt] Don't evaluate large memset (PR62191)

If the memset is large, checking every single byte of the global
may be very slow. Add an upper bound on the size of memset we
handle.

For the common special case of memset zeroinitializer to zero,
add a fastpath that checks just that and is not length limited.

Fixes https://github.com/llvm/llvm-project/issues/62191.

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[test] Switch to use -passes syntax in a bunch of test cases

Should cover most of the tests for GVN, GVNHoist, GVNSink, GlobalOpt,
GlobalSplit, InstCombine, Reassociate, SROA and TailCallElim that
h

[test] Switch to use -passes syntax in a bunch of test cases

Should cover most of the tests for GVN, GVNHoist, GVNSink, GlobalOpt,
GlobalSplit, InstCombine, Reassociate, SROA and TailCallElim that
had not been updated earlier.

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[IR] Switch everything to use memory attribute

This switches everything to use the memory attribute proposed in
https://discourse.llvm.org/t/rfc-unify-memory-effect-attributes/65579.
The old argmemo

[IR] Switch everything to use memory attribute

This switches everything to use the memory attribute proposed in
https://discourse.llvm.org/t/rfc-unify-memory-effect-attributes/65579.
The old argmemonly, inaccessiblememonly and inaccessiblemem_or_argmemonly
attributes are dropped. The readnone, readonly and writeonly attributes
are restricted to parameters only.

The old attributes are auto-upgraded both in bitcode and IR.
The bitcode upgrade is a policy requirement that has to be retained
indefinitely. The IR upgrade is mainly there so it's not necessary
to update all tests using memory attributes in this patch, which
is already large enough. We could drop that part after migrating
tests, or retain it longer term, to make it easier to import IR
from older LLVM versions.

High-level Function/CallBase APIs like doesNotAccessMemory() or
setDoesNotAccessMemory() are mapped transparently to the memory
attribute. Code that directly manipulates attributes (e.g. via
AttributeList) on the other hand needs to switch to working with
the memory attribute instead.

Differential Revision: https://reviews.llvm.org/D135780

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[Intrinsics] Add `nocallback` to the memset/cpy/move intrinsics

These were forgotten when D118680 was applied. Similar to D125937.

Differential Revision: https://reviews.llvm.org/D129516

[GlobalOpt] Fix memset handling in global ctor evaluation (PR55859)

The global ctor evaluator currently handles by checking whether the
memset memory is already zero, and skips it in that case. Howe

[GlobalOpt] Fix memset handling in global ctor evaluation (PR55859)

The global ctor evaluator currently handles by checking whether the
memset memory is already zero, and skips it in that case. However,
it only actually checks the first byte of the memory being set.

This patch extends the code to check all bytes being set. This is
done byte-by-byte to avoid converting undef values to zeros in
larger reads. However, the handling is still not completely correct,
because there might still be padding bytes (though probably this
doesn't matter much in practice, as I'd expect global variable
padding to be zero-initialized in practice).

Mostly fixes https://github.com/llvm/llvm-project/issues/55859.

Differential Revision: https://reviews.llvm.org/D128532

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[GlobalOpt] Add tests for memset with non-zero value (NFC)

[GlobalOpt] Add tests for PR55859 (NFC)