This reverts commit 3d4c0460.

Compile time impact is still high. Need to understand why.

Differential Revision: https://reviews.llvm.org/D92153

We report an error for unknown `DT_PLTREL` values.
This switches the error to warning.

Differential revision: https://reviews.llvm.org/D92087

Previously we tried to using isKnownPredicateAt, but it makes an
extra query to isKnownPredicate, which has negative impact on compile
time. Let's try to use more lightweight isBasicBlockEntryGuardedByCond.

Differential Revision: https://reviews.llvm.org/D92152

This handles cases were the input isn't known to be sign extended.

[RISCV] Add test cases for missed opportunities to use sbsetw/sbclrw/sbinvw when the result isn't known to be sign extended.

If the input isn't sign extended, but the output of the or/xor/and
is used by a sign_inreg we can still use sbsetw/sbclrw/sbinvw.

This reverts commit 14f2ad0e.

Reverting to investigate compile time drop.

Differential Revision: https://reviews.llvm.org/D92152

I recalled Marshall had already made this change. The change is
committed in e3f89a98.

[libc++] [P0966] [C++20] Fix bug PR45368 by correctly implementing P0966: string::reserve should not shrink.

This patch fixes the implementation as well as the tests that didn't actually test the wanted behaviour.
You'll find all the details in the bug report.
It adds as well deprecation warning for reserve() (without argument) and adds a test.

http://wg21.link/P0966R1
https://bugs.llvm.org/show_bug.cgi?id=45368
https://reviews.llvm.org/D54992

Reviewed By: ldionne, #libc

Differential Revision: https://reviews.llvm.org/D91778

It's more future-proof to use isGFX10Plus from the start, on the
assumption that future architectures will be based on current
architectures.

Also make use of the existing isGFX9Plus in a few places.

Differential Revision: https://reviews.llvm.org/D92092

Currently, papers and issues are in separate .csv files (that is easier to update), but I can put them inline.Transforming current html tables into rst are done by the script (attached to the patch FYI but I'll remove it before committing).
I'll of course update RST files before committing to match any modifications that may happen in master branch.

This patch moves the status pages in www/ to RST format in docs/.

It also does some other minor changes: fix copyright year and broken comment end, adds substitutions for coherence (and add colors, but that can be removed easily).
It adds as well redirects from old to new status pages.

Reviewed By: ldionne, #libc

Differential Revision: https://reviews.llvm.org/D92076

After cf1c774d, Clang seems to generate code
that is more similar to icc/Clang, so we can use the same line numbers for
all compilers in this test.

Fixes https://github.com/clangd/clangd/issues/602

Differential Revision: https://reviews.llvm.org/D92148

Differential Revision: https://reviews.llvm.org/D71126

Needed for a future automatic update to RST.

This should make the builder http://lab.llvm.org:8011/#/builders/101/ happy.
It uses gcc-9 and not Tip-Of-Trunk as its name indicates BTW.
GCC-10 passes all these tests.

Fix gcc warnings: -Wsign-compare, -Wparentheses, -Wpragmas.

Reviewed By: ldionne, #libc, #libc_abi

Differential Revision: https://reviews.llvm.org/D92099

This addresses post review comment for D92018.

The warning was:

```
error: loop variable 'Note' is always a copy because the range of type 'iterator_range<llvm::object::ELFFile<llvm::object::ELFType<llvm::support::big, true> >::Elf_Note_Iterator>' (aka 'iterator_range<Elf_Note_Iterator_Impl<ELFType<(llvm::support::endianness)0U, true> > >') does not return a reference [-Werror,-Wrange-loop-analysis]
      for (const typename ELFT::Note &Note : Obj.notes(S, Err))
```

A piece of code in `isLoopBackedgeGuardedByCond` basically duplicates
the dominators traversal from `isBlockEntryGuardedByCond` called from
`isKnownPredicateAt`, but it's less powerful because it does not give context
to `isImpliedCond`. This patch reuses the `isKnownPredicateAt `function there,
reducing the amount of code duplication and making it more powerful.

Differential Revision: https://reviews.llvm.org/D92152
Reviewed By: skatkov

Use more context to prove contextual facts about the last iteration. It is
only executed when the backedge is taken, so we can use `isLoopBackedgeGuardedByCond`
to make this check.

Differential Revision: https://reviews.llvm.org/D91535
Reviewed By: skatkov

[LegalizerTypes] Add support for scalarizing the operand of an FP_EXTEND when the result type is legal.

LoopLoadElim may end up expanding an AddRec from a loop
which is not the current loop. This loop may not be in simplify
form. We figure it out after the no-return point, so cannot bail
in this case.

AddRec requires simplify form to expand. The only way to ensure
this does not crash is to simplify all loops beforehand.

The issue only exists in new PM. Old PM requests LoopSimplify
required pass and it simplifies all loops before the opt begins.

Differential Revision: https://reviews.llvm.org/D91525
Reviewed By: asbirlea, aeubanks

Differential Revision: https://reviews.llvm.org/D92144

Without this extra flag we can't distingish between stub functions and
functions that happen to have address 0 (relative to __table_base).

Adding this flag bit the base symbol class actually avoids growing the
SymbolUnion struct which would not be true if we added it to the
FunctionSymbol subclass (due to bitbacking).

The previous approach of setting it's table index to zero worked for
normal static relocations but not for `-fPIC` code.

See https://github.com/emscripten-core/emscripten/issues/12819

Differential Revision: https://reviews.llvm.org/D92038

We want to find 'sources = [', but only if it's not the prefix
of 'sources = []' -- we're looking for a non-empty list.

No behavior change.

No behavior change, but maybe a bit clearer.

With this, changes like b534beab can be merged automatically.

This is needed for call hierarchy to be able to find callers of
main-file-only functions.

Differential Revision: https://reviews.llvm.org/D92000

This change gives sparse compiler clients more control over selecting
individual types for the pointers and indices in the sparse storage schemes.
Narrower width obviously results in smaller memory footprints, but the
range should always suffice for the maximum number of entries or index value.

Reviewed By: penpornk

Differential Revision: https://reviews.llvm.org/D92126

same type in multiple base classes.

Not even if the type is introduced by distinct declarations (for
example, two typedef declarations, or a typedef and a class definition).

Define ConstantData::PoisonValue.
Add support for poison value to LLLexer/LLParser/BitcodeReader/BitcodeWriter.
Add support for poison value to llvm-c interface.
Add support for poison value to OCaml binding.
Add m_Poison in PatternMatch.

Differential Revision: https://reviews.llvm.org/D71126

This is partly in preparation for an upcoming change that can change the
order in which DeclContext lookup results are presented.

In passing, fix some obvious errors where name lookup's notion of a
"static member function" missed static member function templates, and
where its notion of "same set of declarations" was confused by the same
declarations appearing in a different order.

In https://reviews.llvm.org/D89072 I added static const data members
to the debug subsection for globals. It skipped emitting an S_CONSTANT if it
didn't have a value, which meant the subsection could be empty.

This patch fixes the empty subsection issue.

Differential Revision: https://reviews.llvm.org/D92049

Revert "[compiler-rt] [builtins] Support conversion between fp16 and fp128" & dependency

Revert "[compiler-rt] [builtins] Use _Float16 on extendhfsf2, truncdfhf2 __truncsfhf2 if available"

This reverts commit 7a948298.

This reverts commit 1fb91fcf.

It still had the old name from before ElementwiseMappable was added.