`SCEVUnknown::allUsesReplacedWith` does not need to call `forgetMemoizedResults`
since RAUW does a value-equivalent replacement by assumption. If this
assumption was false then the later setValPtr(New) call would be incorrect too.
This is a non-trivial performance optimization for functions with a large number
of loops since `forgetMemoizedResults` walks all loop backedge taken counts to
see if any of them use the SCEVUnknown being RAUWed. However, this improvement
is difficult to demonstrate without checking in an excessively large IR file.
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Summary:
Previously were in support. Since many many things depend on support,
were all forced to also depend on libxml2, which we only want in a few cases.
This puts all the libxml2 deps in a separate lib to be used only in a few
places.
Reviewers: ruiu, thakis, rnk
Subscribers: mgorny, hiraditya, llvm-commits
Differential Revision: https://reviews.llvm.org/D35819
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The PDB "symbol stream" actually contains symbol records for the publics
and the globals stream. The globals and publics streams are essentially
hash tables that point into a single stream of records. In order to
match cvdump's behavior, we need to only dump symbol records referenced
from the hash table. This patch implements that, and then implements
global stream dumping, since it's just a subset of public stream
dumping.
Now we shouldn't see S_PROCREF or S_GDATA32 records when dumping
publics, and instead we should see those record in the globals stream.
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This is a workaround for the bug described in PR31652 and
http://lists.llvm.org/pipermail/llvm-dev/2017-July/115497.html. The temporary
solution is to add a function EqualityPropUnSafe. In EqualityPropUnSafe, for
some simple patterns we can know the equality comparison may contains undef,
so we regard such comparison as unsafe and will not do loop-unswitching for
them. We also need to disable the select simplification when one of select
operand is undef and its result feeds into equality comparison.
The patch cannot clear the safety issue caused by the bug, but it can suppress
the issue from happening to some extent.
Differential Revision: https://reviews.llvm.org/D35811
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This is needed, among others, to respect --section-ordering-file
with LTO. I'll follow up with a similar change for data sections.
I hope every version of gold available on the bots has support for
--section-ordering file.
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Replace the incorrect variable reference when invalid redirect is used.
This fixes the following issue:
File "/usr/src/llvm/utils/lit/lit/TestRunner.py", line 316, in processRedirects
raise InternalShellError(cmd, "Unsupported redirect: %r" % (r,))
UnboundLocalError: local variable 'r' referenced before assignment
which in turn broke shtest-shell.py and max-failures.py lit tests.
The breakage was introduced during refactoring in rL307310.
Differential Revision: https://reviews.llvm.org/D35857
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As discussed on llvm-dev I've implemented the first basic steps towards
llvm-objcopy/llvm-objtool (name pending).
This change adds the ability to copy (without modification) 64-bit
little endian ELF executables that have SHT_PROGBITS, SHT_NOBITS,
SHT_NULL and SHT_STRTAB sections.
Patch by Jake Ehrlich
Differential Revision: https://reviews.llvm.org/D33964
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As discussed on llvm-dev I've implemented the first basic steps towards
llvm-objcopy/llvm-objtool (name pending).
This change adds the ability to copy (without modification) 64-bit
little endian ELF executables that have SHT_PROGBITS, SHT_NOBITS,
SHT_NULL and SHT_STRTAB sections.
Patch by Jake Ehrlich
Differential Revision: https://reviews.llvm.org/D33964
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Summary:
ELF linkers generate __start_<secname> and __stop_<secname> symbols
when there is a value in a section <secname> where the name is a valid
C identifier. If dead stripping determines that the values declared
in section <secname> are dead, and we then internalize (and delete)
such a symbol, programs that reference the corresponding start and end
section symbols will get undefined reference linking errors.
To fix this, add the section name to the IRSymtab entry when a symbol is
defined in a specific section. Then use this in the gold-plugin to mark
the symbol as external and visible from outside the summary when the
section name is a valid C identifier.
Reviewers: pcc
Subscribers: mehdi_amini, inglorion, eraman, llvm-commits
Differential Revision: https://reviews.llvm.org/D35639
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D35067/rL308322 attempted to support up to 4 load pairs for memcmp inlining which resulted in regressions for some optimized libc memcmp implementations (PR33914).
Until we can match these more optimal cases, this patch reduces the memcmp expansion to a maximum of 2 load pairs (which matches what we do for -Os).
This patch should be considered for the 5.0.0 release branch as well
Differential Revision: https://reviews.llvm.org/D35830
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This patch moves the DAGCombiner::GetDemandedBits function to SelectionDAG::GetDemandedBits as a first step towards making it easier for targets to get to the source of any demanded bits without the limitations of SimplifyDemandedBits.
Differential Revision: https://reviews.llvm.org/D35841
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Summary:
Some SPARC TLS relocations were applying nontrivial adjustments
to zero value, leading to unexpected non-zero values in ELF and then
Solaris linker failures.
Getting rid of these adjustments.
Fixes PR33825.
Reviewers: rafael, asb, jyknight
Subscribers: joerg, jyknight, llvm-commits
Differential Revision: https://reviews.llvm.org/D35567
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it when safe.
Very often the BE count is the trip count minus one, and the plus one
here should fold with that minus one. But because the BE count might in
theory be UINT_MAX or some such, adding one before we extend could in
some cases wrap to zero and break when we scale things.
This patch checks to see if it would be safe to add one because the
specific case that would cause this is guarded for prior to entering the
preheader. This should handle essentially all of the common loop idioms
coming out of C/C++ code once canonicalized by LLVM.
Before this patch, both forms of loop in the added test cases ended up
subtracting one from the size, extending it, scaling it up by 8 and then
adding 8 back onto it. This is really silly, and it turns out made it
all the way into generated code very often, so this is a surprisingly
important cleanup to do.
Many thanks to Sanjoy for showing me how to do this with SCEV.
Differential Revision: https://reviews.llvm.org/D35758
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