Changes

[llvm-cov gcov] Add -r (--relative-only) && -s (--source-prefix)

gcov 4.7 introduced the two options.
https://sourceware.org/pipermail/gcc-patches/2011-November/328782.html

-r only dumps files with relative paths or absolute paths with the prefix
specified by -s. The two options are useful filtering out system header files.

[llvm-cov gcov][test] Unsupport Windows

[JITLink] Improve formatting for Edge, Block and Symbol debugging output.

[SelectionDAG] Move ISD:PARITY formation from DAGCombine to SimplifyDemandedBits.

Previously, we formed ISD::PARITY by looking for (and (ctpop X), 1)
but the AND might be separated from the ctpop. For example if the
parity result is multiplied by 2, we'll pull the AND through the
shift.

So to handle more cases, move to SimplifyDemandedBits where we
can handle more cases that result in only the LSB of the CTPOP
being used.

[docs] Document LLVM_EXTERNALIZE_DEBUGINFO CMake option

Add `LLVM_EXTERNALIZE_DEBUGINFO` to CMake.rst. This should help make dSYM
generation more discoverable.

Differential Revision: https://reviews.llvm.org/D87591

[CodeGenPrepare] Fix zapping dead operands of assume

This patch fixes a problem of the commit 52cc97a0.
A test case is created to demonstrate the crash caused by
the instruction iterator invalidated by the recursive
removal of dead operands of assume. The solution restarts
from the blocks's first instruction in case CurInstIterator
is invalidated by RecursivelyDeleteTriviallyDeadInstructions().

Reviewed By: bkramer

Differential Revision: https://reviews.llvm.org/D87434

[AST][FPEnv] Keep FP options in trailing storage of CastExpr

This is recommit of 6c8041aa0f, reverted in de044f7562 because of some
fails. Original commit message is below.

This change allow a CastExpr to have optional FPOptionsOverride object,
stored in trailing storage. Of all cast nodes only ImplicitCastExpr,
CStyleCastExpr, CXXFunctionalCastExpr and CXXStaticCastExpr are allowed
to have FPOptions.

Differential Revision: https://reviews.llvm.org/D85960

[llvm-cov gcov] Refactor counting and reporting

The current organization of FileInfo and its referenced utility functions of
(GCOVFile, GCOVFunction, GCOVBlock) is messy. Some members of FileInfo are just
copied from GCOVFile. FileInfo::print (.gcov output and --intermediate output)
is interleaved with branch statistics and computation of line execution counts.
--intermediate has to do redundant .gcov output to gather branch statistics.

This patch deletes lots of code and introduces a clearer work flow:

```
fn collectFunction
  for each block b
    for each line lineNum
      let line be LineInfo of the file on lineNum
      line.exists = 1
      increment function's lines & linesExec if necessary
      increment line.count
      line.blocks.push_back(&b)

fn collectSourceLine
  compute cycle counts
  count = incoming_counts + cycle_counts
  if line.exists
    ++summary->lines
    if line.count
      ++summary->linesExec

fn collectSource
  for each line
    call collectSourceLine

fn main
  for each function
    call collectFunction
    print function summary
  for each source file
    call collectSource
    print file summary
    annotate the source file with line execution counts
  if -i
    print intermediate file
```

The output order of functions and files now follows the original order in
.gcno files.

[analyzer] Evaluate PredefinedExpressions

We did not evaluate such expressions, just returned `Unknown` for such cases.
After this patch, we will be able to access a unique value identifying a template instantiation via the value of the `PRETTY_FUNCTION` predefined expression.

Reviewed By: vsavchenko

Differential Revision: https://reviews.llvm.org/D87004

[analyzer][docs][NFC] Document the ento namespace in the llvm/Lexicon

Document the `ento` namespace in the Lexicon according to @nicolas17 on the
mailing list (http://lists.llvm.org/pipermail/cfe-dev/2020-August/066577.html).

The analyzer lived at different namespaces at different times.
Originally lived at the `GR` aka. (Graph Reachability)  namespace [7], later it
moved under the `ento` namespace [9].

The Static Analyzer's code lived at many other places as well:
`Analysis` -[2]-> `Checker` -[5]-> `GR` -[10]> `entoSA` -[11]-> `StaticAnalyzer`

The relevant code motion, refactor commits, cfe-dev mailing in chronological
order:
 1) 2008-03-15 Make a major restructuring of the clang tree: introduce a ...
    7a51313d8a0a358bb92eb5dbf8fd846b7c48e7fe
 2) 2010-01-25 Split libAnalysis into two libraries: libAnalysis and libChecker
    d6b8708643219776b1f0f41df32c5eccf065ed5b
 3) 2010-12-21 Reorganization of Checker files
    http://lists.llvm.org/pipermail/cfe-dev/2010-December/012694.html
 4) 2010-12-22 Refactoring: include/clang/Checker -> include/clang/GR
    8d602a8aa8e6697509465d8a5473fc41cb1a382e
 5) 2010-12-22 Refactoring: lib/Checker -> lib/GR
    2ff5ab1516e48c2fff0138f953d887b5e695214b
 6) 2010-12-22 Refactoring: Move checkers into lib/GR/Checkers and their own
    a700e976b658860418bc145ec0bdacd4f1db3264
 7) 2010-12-22 Refactoring: Move stuff into namespace 'GR'
    ca08fba4141f1d3ae6193b3c81fb6ba8fb10d7dc
 8) 2010-12-22 Refactoring: Drop the 'GR' prefix.
    1696f508e2fe95793ca8bb70d78b88023b6b8625
 9) 2010-12-23 Rename static analyzer namespace 'GR' to 'ento'
    98857c986078c6e6a10910628dbabf75ae735b76
10) 2010-12-23 Rename headers: 'clang/GR' 'clang/EntoSA' and update Makefile
    ef33f0996c6a625767690395f3cfb41afb84db5a
11) 2010-12-23 Chris Lattner has strong opinions about directory
    d99bd55a5e092774214ba31fc5a871bfc31e711c
12) 2010-12-24 Remove the EntoSA directories.
    9d6af5328e3a61641a125b17125952fa1a6bf11d

Reviewed By: Szelethus,martong,ASDenysPetrov,xazax.hun

Differential Revision: https://reviews.llvm.org/D86446

[analyzer][z3] Use more elaborate Z3 variable names

Previously, it was a tedious task to comprehend Z3 dumps.
We will use the same name prefix just as we use in the corresponding dump method

For all `SymbolData` values:
    `$###` -> `conj_$###`
    `$###` -> `derived_$###`
    `$###` -> `extent_$###`
    `$###` -> `meta_$###`
    `$###` -> `reg_$###`

Reviewed By: xazax.hun,mikhail.ramalho

Differential Revision: https://reviews.llvm.org/D86223

[CodeGen] Fix bug in IncrementPointer

In an earlier patch I meant to add the correct flags to the ADD
node when incrementing the pointer, but forgot to pass them to
SelectionDAG::getNode.

Differential Revision: https://reviews.llvm.org/D87496

[ARM] Fix so immediates and pc relative checks

Treating an SoImm offset as a multiple of 4 between -1020 and 1020
mis-handles the second of a pair of 16-bit constants where the offset is a multiple of 2 but not a multiple of 4,
leading to an LLVM ERROR: out of range pc-relative fixup value

For 32-bit and larger (64-bit) constants, continue to treat an SoImm offset as a multiple of 4 between -1020 and 1020.
For smaller (16-bit) constants, treat an SoImm offset as a multiple of 1 between -255 and 255.

Reviewed By: efriedma

Differential Revision: https://reviews.llvm.org/D86949

[UnifyLoopExits] Fix non-deterministic iteration order

This was causing random minor codegen differences in shaders compiled
with the AMDGPU backend.

Differential Revision: https://reviews.llvm.org/D87548

[compiler-rt] [netbsd] Use internal_ptrace() instead of ptrace()

[JumpThreading] Fix an incorrect Modified status

This fixes PR47297.

When ProcessBlock() was able to constant fold the terminator's
condition, but not do any more transformations, the function would
return false, which would lead to the JumpThreading pass returning an
incorrect modified status. This patch makes so that ProcessBlock()
returns true in such cases. This will trigger an unnecessary invocation
of ProcessBlock() in such cases, but this should be rare to occur.

This was caught using the check introduced by D80916.

Reviewed By: efriedma

Differential Revision: https://reviews.llvm.org/D87392

AMDGPU/GlobalISel/Emitter Support for predicate code that uses operands

Predicates with 'let PredicateCodeUsesOperands = 1' want to examine
matched operands. When we encounter predicate code that uses operands,
analyze its named operand arguments and create a map between argument
index and name. Later, when leaf node with name is encountered, emit
GIM_RecordNamedOperand that will store that operand at its argument
index in operand list. This operand list will be an argument to c++
code of the predicate.

Differential Revision: https://reviews.llvm.org/D87285

[clangd] Add error() function for creating formatv-style llvm::Errors. NFC

Summary:
This is considerably terser than the makeStringError and friends, and
avoids verbosity cliffs that discourage adding log information.

It follows the syntax used in log/elog/vlog/dlog that have been successful.

The main caveats are:
 - it's strictly out-of-place in logger.h, though kind of fits thematically and
   in implementation
 - it claims the "error" identifier, which seems a bit too opinionated
   to put higher up in llvm

I've updated some users of StringError mostly at random - there are lots
more mechanical changes but I'd like to get this reviewed before making
them all.

Reviewers: kbobyrev, hokein

Subscribers: mgorny, ilya-biryukov, javed.absar, MaskRay, jkorous, arphaman, kadircet, usaxena95, cfe-commits

Tags: #clang

Differential Revision: https://reviews.llvm.org/D83419

[gn build] Port 30667c967d3

[DebugInstrRef][1/9] Add fields for instr-ref variable locations

Add a DBG_INSTR_REF instruction and a "debug instruction number" field to
MachineInstr. The two allow variable values to be specified by
identifying where the value is computed, rather than the register it lies
in, like so:

  %0 = fooinst, debug-instr-number 1
  [...]
  DBG_INSTR_REF 1, 0

See the original RFC for motivation:
http://lists.llvm.org/pipermail/llvm-dev/2020-February/139440.html

This patch is NFCI; it only adds fields and other boiler plate.

Differential Revision: https://reviews.llvm.org/D85741

[clangd] Track tweaks that fail the apply stage

Differential Revision: https://reviews.llvm.org/D87501

[CodeGen][X86] Regenerate minmax reduction sequence tests to match arithmetic tests.

avx512-reduceIntrin.c wasn't bothering with the exhaustive alloca/store/load/bitcast checks and avx512-reduceMinMaxIntrin.c shouldn't need to either.

This makes it a lot easier to maintain as the update script still doesn't work properly on x86 targets

[clangd] makeStringError,make_error<StringError> -> error()

[LegalizeDAG] Fix MSVC "result of 32-bit shift implicitly converted to 64 bits" warning. NFCI.

AMDGPU/GlobalISel Add test for non-leaf complex patterns

GlobalIsel emitter does not import patterns where complex sub-operand
of a non-leaf complex pattern is referenced more then once. Multiple
references of complex patterns with same name and same sub-operands
represent the same operand. Document this with a test.

AMDGPU/GlobalISel/Emitter Recognize additional 'same operand checks'

The "name" of a non-leaf complex pattern (MY_PAT $op1, $op2) is
"MY_PAT:op1:op2" and the ones with same "name" represent same operand.
Add 'same operand check' for this case.

Differential Revision: https://reviews.llvm.org/D87351

AMDGPU/GlobalISel Check for NoNaNsFPMath in isKnownNeverSNaN

Check for NoNaNsFPMath function attribute in isKnownNeverSNaN.
Function attributes are in held in 'TargetMachine.Options'.
Among other things, this allows selection of some patterns imported
in D87351 since G_FCANONICALIZE is not generated when isKnownNeverSNaN
returns true in lowerFMinNumMaxNum.

However we notice some incorrect results since function attributes are
not correctly written in TargetMachine.Options when next function is
processed. Take a look at @v_test_no_global_nnans_med3_f32_pat0_srcmod0,
it has "no-nans-fp-math"="false" but TargetMachine.Options still has it
set to true since first function in test file had this attribute set to
true. This will be fixed in D87511.

Differential Revision: https://reviews.llvm.org/D87456

[SVE] In LoopIdiomRecognize::isLegalStore bail out for scalable vectors

The function LoopIdiomRecognize::isLegalStore looks for stores in loops
that could be transformed into memset or memcpy. However, the algorithm
currently requires that we know how big the store is at runtime, i.e.
that the store size will not overflow an unsigned integer. For scalable
vectors we cannot guarantee this so I have changed the code to bail out
for now. In addition, even if we add a way to query the maximum value of
vscale in future we will still need to update the algorithm to cope with
non-constant strides. The additional cost associated with calculating
the memset and memcpy arguments will need to be taken into account as
well.

This patch also fixes up an implicit TypeSize -> uint64_t cast,
thereby removing a warning. I've added tests here showing a fixed
width vector loop being transformed into memcpy, and a scalable
vector loop remaining unchanged:

  Transforms/LoopIdiom/memcpy-vectors.ll

Differential Revision: https://reviews.llvm.org/D87439

[ARM][MVE] Tail-predication: check get.active.lane.mask's TC value

This adds additional checks for the original scalar loop tripcount value, i.e.
get.active.lane.mask second argument, and perform several sanity checks to see
if it is of the form that we expect similarly like we already do for the IV
which is the first argument of get.active.lane.

Differential Revision: https://reviews.llvm.org/D86074

[SyntaxTree][List] Fix: `ParameterDeclarationList` is the `List` inside `ParametersAndQualifiers`

Differential Revision: https://reviews.llvm.org/D87598

[SyntaxTree] Provide `List::classof`

Differential Revision: https://reviews.llvm.org/D87599

[SyntaxTree][List] `assertInvariants` for `List`s

Differential Revision: https://reviews.llvm.org/D87600

[ARM] Selects SSAT/USAT from correct LLVM IR

LLVM will canonicalize conditional selectors to a different pattern than the old code that was used.
This is updating the function to match the new expected patterns and select SSAT or USAT when successful.
Tests have also been updated to use the new patterns.

Differential Review: https://reviews.llvm.org/D87379

[DSE] Precommit test case for invalid elimination of store in loop.

[DSE] Only eliminate candidates that always store the same loc.

AliasAnalysis/MemoryLocation does not account for loops. Two
MemoryLocation can be must-overwrite, even if the first one writes
multiple locations in a loop.

This patch prevents removing such stores, by only considering candidates
that are known to be loop invariant, or executed in the same BB.

Currently the invariant check is quite conservative and only considers
Alloca and Alloca-like instructions and arguments as invariant base pointers.
It also considers GEPs with all constant indices and invariant bases as
invariant.

This can be improved in the future, but the current implementation has
only minor impact on the total number of stores eliminated (25903 vs
26047 for the baseline). There are some 2-10% swings for some individual
benchmarks. In roughly half of the cases, the number of stores removed
increases actually, because we skip candidates that are unlikely to be
valid candidates early.

[CGP] Limit converting phi types to simple loads and stores

Instcombine limits converting phi types to simple loads and stores. This
does the same in codegenprepare, not processing phis that are not
simple.

Note that volatile loads/store ISel will happily convert between float
and int. Atomics are more likely to always be integer. This just keeps
things simple and doesn't process either.

Differential Revision: https://reviews.llvm.org/D83770

[mlir] Check for type conversion success in std->llvm function conversion

Type converter may fail and return nullptr on unconvertible types. The function
conversion did not include a check and was attempting to use a nullptr type to
construct an LLVM function, leading to a crash. Add a check and return early.
The rest of the call stack propagates errors properly.

Fixes PR47403.

Reviewed By: mehdi_amini

Differential Revision: https://reviews.llvm.org/D87075

[pstl] Support Threading Building Blocks 2020 (oneTBB) for "tbb" parallel backend.

After the changes the "tbb" parallel backend will work with old TBB versions(TBB_INTERFACE_VERSION <= 12000) and new ones (TBB 2020 and greater)

More about oneTBB:
https://github.com/oneapi-src/oneTBB

Phabricator Review:
https://reviews.llvm.org/D87380

[llvm-readobj/elf][test] - Test all core note types properly.

Currently we don't test all core note types that are defined in
`getCoreNoteTypeName` in ELFDumper.cpp.

Also we don't have a test for an unknown core note type.

This patch fixes it.

Differential revision: https://reviews.llvm.org/D87453

[llvm-readelf/obj] - Refine and generalize the code that is used to dump notes.

There is some code that can be shared between GNU/LLVM styles.
Also, this fixes 2 inconsistencies related to dumping unknown note types:
1) For GNU style we printed "Unknown note type: (0x00000003)" in some cases, and
   "Unknown note type (0x00000003)" (no colon) in other cases.
   GNU readelf always prints `:`. This patch removes the related code
   duplication and does the same.
2) For LLVM style in some cases we printed "Unknown note type (0x00000003)",
   but sometimes just "Unknown (0x00000003)". The latter is the right form, which
   is consistent with other unknowns that are printed in LLVM style.

Rebased on top of D87453.

Differential revision: https://reviews.llvm.org/D87454

[NFC] Add missing `const` statements in SCEV

[llvm-readobj] - Cleanup implementation LLVMStyle<ELFT>::printAddrsig().

It has following issues:
1) `getStaticSymbolName` returns `std::string`, but the code
   assigns a result to `Expected<std::string>`.
2) The code uses `unwrapOrError` and never tests the error reported.

This patch fixes these issues.

Differential revision: https://reviews.llvm.org/D87507

[llvm-readobj/elf] - Don't use unwrapOrError when reporting errors about SHT_DYNAMIC sections.

This changes messages reported to stop using dynamic section names (use `describe()` instead).
This allows to avoid `unwrapOrError` and improves diagnostics.

Differential revision: https://reviews.llvm.org/D87503

Don't dereference from a dyn_cast<>. NFCI.

Use cast<> instead which will assert if it fails and not just return null.

Fixes clang static analyzer warning.

Assert we've found both vector types. NFCI.

Fixes clang static analyzer warning about potential null dereferences.

[AMDGPU] Don't cluster stores

Clustering loads has caching benefits, but as far as I know there is no
advantage to clustering stores on any AMDGPU subtargets.

The disadvantage is that it tends to increase register pressure and
restricts scheduling freedom.

Differential Revision: https://reviews.llvm.org/D85530

[InstSimplify] fix miscompiles with maximum/minimum intrinsics

As discussed in the sibling codegen functionality patch D87571,
this transform was created with D52766, but it is not correct.

The incorrect test diffs were missed during review, but the
'TODO' comment about this functionality was still in the code -
we need 'nnan' to enable this fold.

[ARM] Enable tail predication for reduction tests. NFC

[XCOFF][AIX] Handle TOC entries that could not be reached by positive range in small code model

Summary:
In small code model, AIX assembler could not deal with labels that
could not be reached within the [-0x8000, 0x8000) range from TOC base.
So when generating the assembly, we would need to help the assembler
by subtracting an offset from the label to keep the actual value
within [-0x8000, 0x8000).

Reviewed By: hubert.reinterpretcast, Xiangling_L

Differential Revision: https://reviews.llvm.org/D86879

[InstSimplify] fix test comments; NFC

[InstSimplify] add/move tests for fmin/fmax; NFC

The new tests are duplicated from the sibling patch for codegen:
D87571

[InstSimplify] reduce code duplication for fmin/fmax folds; NFC

We use the same code structure for folding integer min/max.

Add support for casting elements in vectors for certain Std dialect type conversion operations.

Added support to the Std dialect cast operations to do casts in vector types when feasible.

Reviewed By: ftynse

Differential Revision: https://reviews.llvm.org/D87410

[libcxx] ostream{,buf}_iterator::difference_type changes in C++20

In C++20, since P0896R4, std::ostream_iterator and std::ostreambuf_iterator
must have std::ptrdiff_t instead of void as a difference_type.

Tests by Casey Carter (thanks!).

Differential Revision: https://reviews.llvm.org/D87459

Assert we've found the size of each (non-overlapping) structure. NFCI.

Fixes clang static analyzer warning.

[MemorySSA] Precommit test case for PR47498.

[MemorySSA] Make sure PerformedPhiTrans is updated for each visited def.

1ce82015f6d0 added a fix to restrict phi optimizations after phi
translations. But the current use of performedPhiTranslation only
checked whether phi translation happened for the first iterator and
missed cases where phi translations happens at subsequent
iterators/upwards defs.

This patch changes upward_defs_iteartor to take a pointer to a bool, so
we can easily ensure the final value includes all visited defs, while
still being able to conveniently use it with make_range & co.

[InstSimplify] allow folds for fmin/fmax with 'ninf'

maxnum(ninf X, +FLT_MAX) --> +FLT_MAX
minnum(ninf X, -FLT_MAX) --> -FLT_MAX

This is based on the similar codegen transform proposed in:
D87571