The normal scheme for tail folding reductions is to use:

loop:
  p = phi(0, a)
  mask = ...
  x = masked_load(..., mask)
  a = add(x, p)
s = select(mask, a, p)

This means we need to keep the register p and a alive out of the loop, plus
the mask. On a target with predicated operations we can instead generate
the phi as p = phi(0, s). This ensures the select in the loop and we can
fold select(m, add(a, b), c) to something like a vaddt c, a, b using the
m predicate. This in turn allows us to tail predicate the entire loop.

Differential Revision: https://reviews.llvm.org/D84741

This reverts commit d58fd4e5. This broke
compiler-rt compilation on macOS:

codesign --sign - /Users/buildslave/jenkins/workspace/lldb-cmake/lldb-build/lib/clang/12.0.99/lib/darwin/libclang_rt.tsan_ios_dynamic.dylib
ld: warning: ignoring file projects/compiler-rt/lib/tsan/CMakeFiles/clang_rt.tsan_ios_dynamic.dir/rtl/tsan_rtl_amd64.S.o, building for iOS-arm64 but attempting to link with file built for iOS Simulator-x86_64
ld: warning: ignoring file projects/compiler-rt/lib/tsan/CMakeFiles/clang_rt.tsan_ios_dynamic.dir/rtl/tsan_rtl_aarch64.S.o, building for iOS-arm64 but attempting to link with file built for iOS Simulator-x86_64
Undefined symbols for architecture arm64:
  "_wrap__setjmp", referenced from:
      substitution__setjmp in tsan_interceptors_posix.cpp.o
  "_wrap_setjmp", referenced from:
      substitution_setjmp in tsan_interceptors_posix.cpp.o
  "_wrap_sigsetjmp", referenced from:
      substitution_sigsetjmp in tsan_interceptors_posix.cpp.o
ld: symbol(s) not found for architecture arm64

This is very similar to D85968, only more elusive to since we were not
adding the typedef type to the relevant DeclContext until D86140, which
meant that the DeclContext was populated (and the relevant assertion
hit) only after importing the type into the expression ast in a
particular way.

I haven't checked whether this situation can be hit in the gmodules
case, but my money is on "yes".

Differential Revision: https://reviews.llvm.org/D86216

The action='store_true' option of argparse.add_argument implicitly
generates a default value of False if the argument is not specified.
Thus, the allow_enabling_alpha_checkers argument of
get_tidy_invocation is never None.

Currently, clangd crashes when opening a file with `#pragma clang __debug parser_crash` (e.g. clang/test/Modules/Inputs/crash.h).
This patch disables these crashes.

Reviewed By: kadircet

Differential Revision: https://reviews.llvm.org/D86279

This was accidentally added in 53b9199a

Differential Revision: https://reviews.llvm.org/D86284

The getSrcFromCopy helper nowadays return a MachineOperand pointer,
so talking about zero_reg was incorrect as it nowadays return
a nullptr when not finding a copy like instruction.

This addresses a FIXME in ASTReader.

Modules were already re-exported for Preprocessor, but not for Sema.
The result was that, with -fmodules-local-submodule-visibility, all AST
nodes belonging to a module that was loaded in a premable where not
accesible from the main part of the file and a diagnostic recommending
importing those modules would be generated.

Differential Revision: https://reviews.llvm.org/D86069

When preamble contains #undef, indexing code finds the matching #define
and uses that during indexing. However, it would only look for local
definitions. If the macro was defined in a module, MacroInfo
would be nullptr and clangd would crash.

This change makes clangd ignore any #undef without a matching #define
inside the same TU.

The indexing of macros happens for preamble only, so then #undef must be
in the preamble, which is why we need two .h files in a test.

Note that clangd is currently not ready for module support, but this
brings us one step closer.

This was previously attempted in
4061d9e4, but had to be reverted due to
broken test. This version fixes that test-only bug by setting a custom module
cache path to avoid re-use of modules across test invocations.

Differential Revision: https://reviews.llvm.org/D85923

Currently, although we handle `CallBase` case in updateImpl, we give up in initialize in the case.
That is problematic when we propagate a range from call site returned position to floating position.

Reviewed By: jdoerfert

Differential Revision: https://reviews.llvm.org/D86196

http://lab.llvm.org:8011/builders/llvm-clang-x86_64-expensive-checks-ubuntu/builds/8256/steps/test-check-all/logs/FAIL%3A%20LLVM%3A%3Athinlto-function-summary-paramaccess.ll

Reviewed By: RKSimon

Differential Revision: https://reviews.llvm.org/D86053

This reverts commit 455d5a8a.

It broke UBSan:
http://lab.llvm.org:8011/builders/sanitizer-x86_64-linux-bootstrap-ubsan/builds/21386/steps/check-llvm%20ubsan/logs/stdio

/b/sanitizer-x86_64-linux-bootstrap-ubsan/build/llvm-project/llvm/test/tools/llvm-readobj/ELF/malformed-pt-dynamic.test:62:10: error: WARN3: expected string not found in input
# WARN3: error: '[[FILE]]': Invalid data was encountered while parsing the file
         ^
<stdin>:2:1: note: scanning from here
/b/sanitizer-x86_64-linux-bootstrap-ubsan/build/llvm-project/llvm/tools/llvm-readobj/ELFDumper.cpp:1956:46: runtime error: addition of unsigned offset to 0x0000020c5b30 overflowed to 0x0000020c5b2f
^
<stdin>:2:1: note: with "FILE" equal to "/b/sanitizer-x86_64-linux-bootstrap-ubsan/build/llvm_build_ubsan/test/tools/llvm-readobj/ELF/Output/malformed-pt-dynamic\\.test\\.tmp3"
/b/sanitizer-x86_64-linux-bootstrap-ubsan/build/llvm-project/llvm/tools/llvm-readobj/ELFDumper.cpp:1956:46: runtime error: addition of unsigned offset to 0x0000020c5b30 overflowed to 0x0000020c5b2f
^
<stdin>:2:117: note: possible intended match here
/b/sanitizer-x86_64-linux-bootstrap-ubsan/build/llvm-project/llvm/tools/llvm-readobj/ELFDumper.cpp:1956:46: runtime error: addition of unsigned offset to 0x0000020c5b30 overflowed to 0x0000020c5b2f
                                                                                                                    ^
Input file: <stdin>
Check file: /b/sanitizer-x86_64-linux-bootstrap-ubsan/build/llvm-project/llvm/test/tools/llvm-readobj/ELF/malformed-pt-dynamic.test

For scalable vector shifts the prediacte is typically all active,
which gets selected to an unpredicated shift by immediate.  When
code generating for fixed length vectors the predicate is based
on the vector length and so additional patterns are required to
make use of SVE's predicated shift by immediate instructions.

Differential Revision: https://reviews.llvm.org/D86204

When removing a non-constant store to a global in
CleanupPointerRootUsers(), the GlobalOpt pass could incorrectly return
false.

This was caught using the check introduced by D80916.

Reviewed By: efriedma

Differential Revision: https://reviews.llvm.org/D86149

Relanded since the buildbot issue was unrelated to this commit.

When hoisting simple values out from a loop, and an optsize attribute, a
convergent call, or an invoke instruction hindered the pass from
unswitching the loop, the pass would return an incorrect Modified
status.

This was caught using the check introduced by D80916.

Reviewed By: asbirlea

Differential Revision: https://reviews.llvm.org/D86085

The byte swapping, when dealing with 4 byte (float) FP constants
in DwarfExpression::addConstantFP, added in commit ef8992b9
was not correct. It always performed byte swapping using an
uint64_t value. When dealing with 4 byte values the 4 interesting
bytes ended up in the big end of the uint64_t, but later we emitted
the 4 bytes at the little end. So we ended up with zeroes being
emitted and faulty debug information.

This patch simplifies things a bit, IMHO. Using the APInt
representation throughout the function, instead of looking at
the internal representation using getRawBytes and without using
reinterpret_cast etc. And using API.byteSwap() should result in
correct byte swapping independent of APInt being 4 or 8 bytes.

Differential Revision: https://reviews.llvm.org/D86272

The code that reports "PT_DYNAMIC segment offset + size exceeds the size of the file"
has an issue: it is possible to bypass the validation by overflowing the size + offset result.

Differential revision: https://reviews.llvm.org/D85519

This reverts commit dfd447c2.

After I pushed this commit, llvm-sphinx-docs started failing, due to:

  Warning, treated as error:
  extension 'recommonmark' has no setup() function;
  is it really a Sphinx extension module?

I don't see how this commit may have caused that, but I'm still
reverting it since I don't know how to proceed with that
troubleshooting.

Differential revision: https://reviews.llvm.org/D73698

When sampling from images with coordinates that only have 16 bit
accuracy, convert the image intrinsic call to use a16 or g16.
This does only happen if the target hardware supports it.

An alternative would be to always apply this combination, independent of
the target hardware and extend 16 bit arguments to 32 bit arguments
during legalization. To me, this sounds like an unnecessary roundtrip
that could prevent some further InstCombine optimizations.

Differential Revision: https://reviews.llvm.org/D85887

The check for the landingpad instructions was overly restrictive. In optimimized builds PHI nodes can appear
before the landingpad instructions, resulting in a fallback to SelectionDAG.

This change relaxes the check to allow PHI nodes.

Reviewed By: arsenm

Differential Revision: https://reviews.llvm.org/D86141

Currently we have to set 'Machine' to something in our
YAML descriptions. Usually we use 'EM_X86_64' for 64-bit targets
and 'EM_386' for 32-bit targets. At the same time, in fact, in most
cases our tests do not need a machine type and we can use
'EM_NONE'.

This is cleaner, because avoids the need of using a particular machine.

In this patch I've made the 'Machine' key optional (the default value,
when it is not specified is `EM_NONE`) and removed it (where possible)
from yaml2obj, obj2yaml and llvm-readobj tests.

There are few tests left where I decided not to remove it, because
I didn't want to touch CHECK lines or doing anything more complex
than a removing a "Machine: *" line and formatting lines around.

Differential revision: https://reviews.llvm.org/D86202

The tests were not written with update_cc_test_checks
in mind, which make them difficult to update. Fix this.

Also, some of the consteval tests were outright broken,
since the CHECK lines were wrong.

Other than this, the semantics of the tests are preserved.

This patch adds a convenience class for using FixedPointSemantics
to build fixed-point operations in IR.

RFC: http://lists.llvm.org/pipermail/llvm-dev/2020-August/144025.html

Reviewed By: rjmccall

Differential Revision: https://reviews.llvm.org/D85314

This patch moves FixedPointSemantics and APFixedPoint
from Clang to LLVM ADT.

This will make it easier to use the fixed-point
classes in LLVM for constructing an IR builder for
fixed-point and for reusing the APFixedPoint class
for constant evaluation purposes.

RFC: http://lists.llvm.org/pipermail/llvm-dev/2020-August/144025.html

Reviewed By: leonardchan, rjmccall

Differential Revision: https://reviews.llvm.org/D85312

In D79719, LayoutField was refactored to fetch the size of field
types in bits and then convert to chars, rather than fetching
them in chars directly. This is not ideal, since it makes the
calculations char size dependent, and breaks for sizes that
are not a multiple of the char size.

This patch changes it to use getTypeInfoInChars instead of
getTypeInfo.

Reviewed By: efriedma

Differential Revision: https://reviews.llvm.org/D85191

This patch adds the capability to perform constraint redundancy checks for `FlatAffineConstraints` using `Simplex`, via a new member function `FlatAffineConstraints::removeRedundantConstraints`. The pre-existing redundancy detection algorithm runs a full rational emptiness check for each inequality separately for checking redundancy. Leveraging the existing `Simplex` infrastructure, in this patch we have an algorithm for redundancy checks that can check each constraint by performing pivots on the tableau, which provides an alternative to running Fourier-Motzkin elimination for each constraint separately.

Differential Revision: https://reviews.llvm.org/D84935

The `UnrollMaxBlockToAnalyze` parameter is used at the stage when we have no
information about a loop body BB cost. In some cases, e.g. for simple loop
```
for(int i=0; i<32; ++i){
  D = Arr2[i*8 + C1];
  Arr1[i*64 + C2] += C3 * D;
  Arr1[i*64 + C2 + 2048] += C4 * D;
}

```
current default parameter value is not enough to run deeper cost analyze so the
loop is not completely unrolled.

Reviewed By: rampitec

Differential Revision: https://reviews.llvm.org/D86248

It isn't very wise to pass an assembly file to the compiler and tell it to compile as a C file and hope that the compiler recognizes it as assembly instead.
Instead enable the ASM language and mark the files as being ASM.

[525/634] Building C object lib/tsan/CMakeFiles/clang_rt.tsan-aarch64.dir/rtl/tsan_rtl_aarch64.S.o
FAILED: lib/tsan/CMakeFiles/clang_rt.tsan-aarch64.dir/rtl/tsan_rtl_aarch64.S.o
/opt/tooling/drive/host/bin/clang --target=aarch64-linux-gnu -I/opt/tooling/drive/llvm/compiler-rt/lib/tsan/.. -isystem /opt/tooling/drive/toolchain/opt/drive/toolchain/include -x c -Wall -Wno-unused-parameter -fno-lto -fPIC -fno-builtin -fno-exceptions -fomit-frame-pointer -funwind-tables -fno-stack-protector -fno-sanitize=safe-stack -fvisibility=hidden -fno-lto -O3 -gline-tables-only -Wno-gnu -Wno-variadic-macros -Wno-c99-extensions -Wno-non-virtual-dtor -fPIE -fno-rtti -Wframe-larger-than=530 -Wglobal-constructors --sysroot=. -MD -MT lib/tsan/CMakeFiles/clang_rt.tsan-aarch64.dir/rtl/tsan_rtl_aarch64.S.o -MF lib/tsan/CMakeFiles/clang_rt.tsan-aarch64.dir/rtl/tsan_rtl_aarch64.S.o.d -o lib/tsan/CMakeFiles/clang_rt.tsan-aarch64.dir/rtl/tsan_rtl_aarch64.S.o -c /opt/tooling/drive/llvm/compiler-rt/lib/tsan/rtl/tsan_rtl_aarch64.S
/opt/tooling/drive/llvm/compiler-rt/lib/tsan/rtl/tsan_rtl_aarch64.S:29:1: error: expected identifier or '('
.section .text
^
1 error generated.

Fixed Clang not being passed as the assembly compiler for compiler-rt runtime build.

Patch By: tambre

Differential Revision: https://reviews.llvm.org/D85706

Use the stack to save and restore the link register when there is no
available register to do it.

Differential Revision: https://reviews.llvm.org/D76069

When hoisting simple values out from a loop, and an optsize attribute, a
convergent call, or an invoke instruction hindered the pass from
unswitching the loop, the pass would return an incorrect Modified
status.

This was caught using the check introduced by D80916.

Reviewed By: asbirlea

Differential Revision: https://reviews.llvm.org/D86085

The internal version is now part of the SCC, make sure to perform this
update.

Comparison against null is a common pattern that usually is followed by
error handling code and the likes. We now use AANonNull to simplify
these comparisons optimistically in order to make more code dead early
on.

Reviewed By: uenoku

Differential Revision: https://reviews.llvm.org/D86145

`AADereferenceable::getAssumedDereferenceableBytes()` is actually
deducing `dereferenceable_or_null`. We should not use that information
to deduce `nonnull`, since it doesn't imply `nonnull`.