Summary:
The C runner utils API was still not vanilla enough for certain use
cases on embedded ARM SDKs, this enables such cases.

Adding people more widely for historical Windows related build issues.

Differential Revision: https://reviews.llvm.org/D76031

Summary:
This patch adds the following intrinsics for non-temporal gather loads
and scatter stores:
  * aarch64_sve_ldnt1_gather_index
  * aarch64_sve_stnt1_scatter_index
These intrinsics implement the "scalar + vector of indices" addressing
mode.

As opposed to regular and first-faulting gathers/scatters, there's no
instruction that would take indices and then scale them. Instead, the
indices for non-temporal gathers/scatters are scaled before the
intrinsics are lowered to `ldnt1` instructions.

The new ISD nodes, GLDNT1_INDEX and SSTNT1_INDEX, are only used as
placeholders so that we can easily identify the cases implemented in
this patch in performGatherLoadCombine and performScatterStoreCombined.
Once encountered, they are replaced with:
  * GLDNT1_INDEX -> SPLAT_VECTOR + SHL + GLDNT1
  * SSTNT1_INDEX -> SPLAT_VECTOR + SHL + SSTNT1

The patterns for lowering ISD::SHL for scalable vectors (required by
this patch) were missing, so these are added too.

Reviewed By: sdesmalen

Differential Revision: https://reviews.llvm.org/D75601

This is part of the IR sibling for:
D75576

Related transform committed with:
rG8ec71585

[libcxxabi] Set LIBCXXABI_LINK_TESTS_WITH_SHARED_LIBCXX to ON if LIBCXX_ENABLE_SHARED is not defined

Differential Revision: https://reviews.llvm.org/D71894

Global properties are shared between debugger instances and
if a test doesn't clear changes in settings it made,
this leads to side effects in other tests.

Differential Revision: https://reviews.llvm.org/D75537

This is part of the IR sibling for:
D75576

(I'm splitting part of the transform as a separate commit
to reduce risk. I don't know of any bugs that might be
exposed by this improved folding, but it's hard to see
those in advance...)

Lets us remove another SLM proc family flag usage.

This is NFC, but we should probably check whether atom/glm/knl? should be using this flag as well...

(In addition to the deprecation bit, this is useful on Windows
where people might have grep but not fgrep.)

Adapted from codegen tests seen in D75576.

If a producer emits a nonzero segment size, `lldb` will silently read
incorrect values and crash, or do something worse later as the tuple
size is expected to be 2, rather than 3.

Neither LLVM, nor GCC produce segmented aranges, but this dangerous case
should still be checked and handled.

Reviewed by: clayborg, labath
Differential Revision: https://reviews.llvm.org/D75925
Subscribers: lldb-commits
Tags: #lldb

This patch switches SCCP to use ValueLatticeElement for lattice values,
instead of the local LatticeVal, as first step to enable integer range support.

This patch does not make use of constant ranges for additional operations
and the only difference for now is that integer constants are represented by
single element ranges. To preserve the existing behavior, the following helpers
are used

* isConstant(LV): returns true when LV is either a constant or a constant range with a single element. This should return true in the same cases where LV.isConstant() returned true previously.
* getConstant(LV): returns a constant if LV is either a constant or a constant range with a single element. This should return a constant in the same cases as LV.getConstant() previously.
* getConstantInt(LV): same as getConstant, but additionally casted to ConstantInt.

Reviewers: davide, efriedma, mssimpso

Reviewed By: efriedma

Differential Revision: https://reviews.llvm.org/D60582

The initialization order was not correct. These bugs were discovered by
valgrind. They appear to work fine in practice but this patch should
unblock switching the AVR backend on by default as now a standard AVR
llc invocation runs without memory errors.

The AVRISelLowering constructor would run before the subtarget boolean
fields were initialized to false. Now, the initialization order is
correct.

As discussed in https://reviews.llvm.org/D59214#1916596
and in some other reviews dealing with FPenv,
bits in Stmt are scarce, and i got so burnout with D59214
and https://bugs.llvm.org/show_bug.cgi?id=40563 specifically
that i never actually followed up with the usages for this bit.

So let's unhoard it, at least for now?

Now that D75114 has landed, DAGCombiner handles this case so the code is redundant.

Summary:
This adds the ACLE intrinsic family for the VFMA and VFMS
instructions, which perform fused multiply-add on vectors of floats.

I've represented the unpredicated versions in IR using the cross-
platform `@llvm.fma` IR intrinsic. We already had isel rules to
convert one of those into a vector VFMA in the simplest possible way;
but we didn't have rules to detect a negated argument and turn it into
VFMS, or rules to detect a splat argument and turn it into one of the
two vector/scalar forms of the instruction. Now we have all of those.

The predicated form uses a target-specific intrinsic as usual, but
I've stuck to just one, for a predicated FMA. The subtraction and
splat versions are code-generated by passing an fneg or a splat as one
of its operands, the same way as the unpredicated version.

In arm_mve_defs.h, I've had to introduce a tiny extra piece of
infrastructure: a record `id` for use in codegen dags which implements
the identity function. (Just because you can't declare a Tablegen
value of type dag which is //only// a `$varname`: you have to wrap it
in something. Now I can write `(id $varname)` to get the same effect.)

Reviewers: dmgreen, MarkMurrayARM, miyuki, ostannard

Reviewed By: dmgreen

Subscribers: kristof.beyls, hiraditya, danielkiss, cfe-commits, llvm-commits

Tags: #clang, #llvm

Differential Revision: https://reviews.llvm.org/D75998

Summary:
We were generating the declarations of polymorphic intrinsics using
`__attribute__((overloadable))`. But `overloadable` is a valid
identifier for an end user to define as a macro in a C program, and if
they do that before including `<arm_mve.h>`, then we shouldn't cause a
compile error.

Fixed to spell the attribute name `__overloadable__` instead.

Reviewers: miyuki, MarkMurrayARM, ostannard

Reviewed By: miyuki

Subscribers: kristof.beyls, dmgreen, danielkiss, cfe-commits

Tags: #clang

Differential Revision: https://reviews.llvm.org/D75997

Found by the LLVM MemorySanitizer tests when switching AVR to a default
backend.

ELFArch must be initialized before the call to
initializeSubtargetDependencies().

The uninitialized read would occur deep within TableGen'd code.

Reviewers: hokein

Subscribers: ilya-biryukov, MaskRay, jkorous, arphaman, kadircet, usaxena95, cfe-commits

Tags: #clang

Differential Revision: https://reviews.llvm.org/D76053

Summary:
This patch replaces incorrectt assert with a check. Previously it asserts that
if SCEV cannot prove `isKnownPredicate(A != B)`, then it should be able to prove
`isKnownPredicate(A == B)`.

Both these fact may be not provable. It is shown in the provided test:

Could not prove: `{-294,+,-2}<%bb1> !=  0`
Asserting: `{-294,+,-2}<%bb1> == 0`

Obviously, this SCEV is not equal to zero, but 0 is in its range so we cannot
also prove that it is not zero.

Instead of assert, we should be checking the required conditions explicitly.

Reviewers: lebedev.ri, fhahn, sanjoy, fedor.sergeev
Reviewed By: lebedev.ri
Subscribers: hiraditya, zzheng, javed.absar, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D76050

Summary: Copy of https://reviews.llvm.org/D72072, submitting with ilya-biryukov's permission.

Reviewers: gribozavr2

Reviewed By: gribozavr2

Subscribers: cfe-commits

Tags: #clang

Differential Revision: https://reviews.llvm.org/D76001

Summary: The return type modification has already been implemented in rL364840 and rL365290.

Reviewers: ldionne, mclow.lists, EricWF, #libc!

Reviewed By: ldionne

Subscribers: christof, dexonsmith, libcxx-commits

Tags: #libc

Differential Revision: https://reviews.llvm.org/D70275

Summary: This patch adds the basic utilities to deal with dropable uses. dropable uses are uses that we rather drop than prevent transformations, for now they are limited to uses in llvm.assume.

Reviewers: jdoerfert, sstefan1

Reviewed By: jdoerfert

Subscribers: uenoku, lebedev.ri, mgorny, hiraditya, dexonsmith, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D73404

Reviewers: lebedev.ri, jdoerfert

Reviewed By: jdoerfert

Subscribers: jdoerfert, dexonsmith, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D74967

This patch adds basic strict-fp intrinsics support to PowerPC backend,
including basic arithmetic operations (add/sub/mul/div).

Reviewed By: steven.zhang, andrew.w.kaylor

Differential Revision: https://reviews.llvm.org/D63916

Summary:
Cost modelling strikes again.
In PR44668 <https://bugs.llvm.org/show_bug.cgi?id=44668> patch series,
i've made the same mistake of always using generic `getOperationCost()`
that i missed in reviewing D73480/D74495 which was later fixed
in 62dd44d7.

We should be using more specific hooks instead - `getCastInstrCost()`,
`getArithmeticInstrCost()`, `getCmpSelInstrCost()`.

Evidently, this does not have an effect on the existing testcases,
with unchanged default cost budget. But if it *does* have an effect
on some target, we'll have to segregate tests that use this function
per-target, much like we already do with other TTI-aware transform tests.

There's also an issue that @samparker has brought up in post-commit-review:
>>! In D73501#1905171, @samparker wrote:
> Hi,
> Did you get performance numbers for these patches? We track the performance
> of our (Arm) open source DSP library and the cost model fixes were generally
> a notable improvement, so many thanks for that! But the final patch
> for rewriting exit values has generally been bad, especially considering
> the gains from the modelling improvements. I need to look into it further,
> but on my current test case I'm seeing +30% increase in stack accesses
> with a similar decrease in performance.
> I'm just wondering if you observed any negative effects yourself?

I don't know if this addresses that, or we need D66450 for that.

Reviewers: samparker, spatel, mkazantsev, reames, wmi

Reviewed By: reames

Subscribers: kristof.beyls, hiraditya, danielkiss, llvm-commits, samparker

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D75908

Summary: When narrowing a scalar G_EXTRACT where the destination lines up perfectly with a single result of the emitted G_UNMERGE_VALUES a COPY should be emitted instead of unconditionally trying to emit a G_MERGE_VALUES.

Reviewers: arsenm, dsanders

Reviewed By: arsenm

Subscribers: wdng, rovka, hiraditya, volkan, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D75743

The note section type implies a specific format that this section does
not have thus tools like readelf fail here. Progbits has no format and
another pipeline compiler already sets the type to progbits.

Differential Revision: https://reviews.llvm.org/D75913

Delete dead code from 8fffa404.

Summary:
Currently, a BoundaryAlign fragment may be inserted after the branch
that needs to be aligned to truncate the current fragment, this fragment is
unused at most of time. To avoid that, we can insert a new empty Data
fragment instead. Non-relaxable instruction is usually emitted into Data
fragment, so the inserted empty Data fragment will be reused at a high
possibility.

Reviewers: annita.zhang, reames, MaskRay, craig.topper, LuoYuanke, jyknight

Reviewed By: reames, LuoYuanke

Subscribers: llvm-commits, dexonsmith, hiraditya

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D75438

Add the workaround for the X86::MOV16ri when describing call site
parameters.

This reverts commit dfecec65.

Merging the change revealed that there is a failure on the memory
sanitizer bots.

    Command Output (stderr):
    --
    ==3569==WARNING: MemorySanitizer: use-of-uninitialized-value
        #0 0x1d71bff in
           llvm::AVRSubtarget::ParseSubtargetFeatures(llvm::StringRef,
    llvm::StringRef)
    /b/sanitizer-x86_64-linux-fast/build/llvm_build_msan/lib/Target/AVR/AVRGenSubtargetInfo.inc:471:7
        #1 0x1d721f8 in initializeSubtargetDependencies
           /b/sanitizer-x86_64-linux-fast/build/llvm-project/llvm/lib/Target/AVR/AVRSubtarget.cpp:50:3
        #2 0x1d721f8 in llvm::AVRSubtarget::AVRSubtarget(llvm::Triple
           const&, std::__1::basic_string<char, std::__1::char_traits<char>,
    std::__1::allocator<char> > const&, std::__1::basic_string<char,
    std::__1::char_traits<char>, std::__1::allocator<char> > const&,
    llvm::AVRTargetMachine const&)
    /b/sanitizer-x86_64-linux-fast/build/llvm-project/llvm/lib/Target/AVR/AVRSubtarget.cpp:33:18
        #3 0x1d3077f in
           llvm::AVRTargetMachine::AVRTargetMachine(llvm::Target const&,
    llvm::Triple const&, llvm::StringRef, llvm::StringRef,
    llvm::TargetOptions const&, llvm::Optional<llvm::Reloc::Model>,
    llvm::Optional<llvm::CodeModel::Model>, llvm::CodeGenOpt::Level, bool)
    /b/sanitizer-x86_64-linux-fast/build/llvm-project/llvm/lib/Target/AVR/AVRTargetMachine.cpp:52:7
        #4 0x1d3169d in
           llvm::RegisterTargetMachine<llvm::AVRTargetMachine>::Allocator(llvm::Target
    const&, llvm::Triple const&, llvm::StringRef, llvm::StringRef,
    llvm::TargetOptions const&, llvm::Optional<llvm::Reloc::Model>,
    llvm::Optional<llvm::CodeModel::Model>, llvm::CodeGenOpt::Level, bool)
    /b/sanitizer-x86_64-linux-fast/build/llvm-project/llvm/include/llvm/Support/TargetRegistry.h:1121:16
        #5 0x86662f in createTargetMachine
           /b/sanitizer-x86_64-linux-fast/build/llvm-project/llvm/include/llvm/Support/TargetRegistry.h:402:12
        #6 0x86662f in compileModule(char**, llvm::LLVMContext&)
           /b/sanitizer-x86_64-linux-fast/build/llvm-project/llvm/tools/llc/llc.cpp:473:52
        #7 0x861f42 in main
           /b/sanitizer-x86_64-linux-fast/build/llvm-project/llvm/tools/llc/llc.cpp:356:22
        #8 0x7f76f7b072e0 in __libc_start_main
           (/lib/x86_64-linux-gnu/libc.so.6+0x202e0)
        #9 0x7ebbc9 in _start
           (/b/sanitizer-x86_64-linux-fast/build/llvm_build_msan/bin/llc+0x7ebbc9)

    SUMMARY: MemorySanitizer: use-of-uninitialized-value
    /b/sanitizer-x86_64-linux-fast/build/llvm_build_msan/lib/Target/AVR/AVRGenSubtargetInfo.inc:471:7
    in llvm::AVRSubtarget::ParseSubtargetFeatures(llvm::StringRef,
    llvm::StringRef)
    Exiting
    FileCheck error: '<stdin>' is empty.
    --

The patch wiill be re-committed once fixed.

Summary:
This patch makes the AVR backend an official target of LLVM, serving
as a request for comments for moving the AVR backend out of
experimental.

A future patch will move the LLVM AVR buildbot (llvm-avr-linux) from the
staging buildmaster to the production buildmaster, so error emails will
start to go out.

Summary of the backend
----------------------

  - 16-bit little endian
  - AsmParser based assembly parser
  - uses the MC library for generating AVR ELFs
  - most logic driven from standard TableGen-erated tables like other
    backends
  - passes all of the test suite under `check-all`, including generic
    CodeGen and DebugInfo tests
  - Used in two frontends
  - Limited, but functional support for DebugInfo and LLVM DWARF dumping
  - Binary compatible with AVR-GCC and avr-{libc,libgcc} for the most part
  - Cannot lower 32-bit shifts due to a bug, can lower shifts larger or
    smaller
  - Supports assembly/MC for all the entire AVR ISA, generally generates poorly
    optimized machine instructions, with most focus thus far on correctness

I've added reviewers and subscribers from previous patches where backends were made official,
and those who participated in the recent thread on llvm-dev, please add anybody I've missed.

The most recent discussion on this topic can be found in the llvm-dev thread [Moving the AVR backend out of experimental](https://lists.llvm.org/pipermail/llvm-dev/2020-February/139158.html)

Reviewers: chandlerc, lattner, rengolin, tstellar, arsenm, thakis, simoll, asb

Reviewed By: rengolin, thakis

Subscribers: CryZe, wdng, mgorny, aprantl, Jim, hans, aykevl, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D75099