Changes

[lldb] Modernize PseudoTerminal::OpenFirstAvailablePrimary

replace char*+length combo with llvm::Error

[lldb-server][linux] Add ability to allocate memory

This patch adds support for the _M and _m gdb-remote packets, which
(de)allocate memory in the inferior. This works by "injecting" a
m(un)map syscall into the inferior. This consists of:
- finding an executable page of memory
- writing the syscall opcode to it
- setting up registers according to the os syscall convention
- single stepping over the syscall

The advantage of this approach over calling the mmap function is that
this works even in case the mmap function is buggy or unavailable. The
disadvantage is it is more platform-dependent, which is why this patch
only works on X86 (_32 and _64) right now. Adding support for other
linux architectures should be easy and consist of defining the
appropriate syscall constants. Adding support for other OSes depends on
the its ability to do a similar trick.

Differential Revision: https://reviews.llvm.org/D89124

Revert "Reland "[SCEV] Model ptrtoint(SCEVUnknown) cast not as unknown, but as zext/trunc/self of SCEVUnknown"" and it's follow-ups

While we haven't encountered an earth-shattering problem with this yet,
by now it is pretty evident that trying to model the ptr->int cast
implicitly leads to having to update every single place that assumed
no such cast could be needed. That is of course the wrong approach.

Let's back this out, and re-attempt with some another approach,
possibly one originally suggested by Eli Friedman in
https://bugs.llvm.org/show_bug.cgi?id=46786#c20
which should hopefully spare us this pain and more.

This reverts commits 1fb610429308a7c29c5065f5cc35dcc3fd69c8b1,
7324616660fc0995fa8c166e3c392361222d5dbc,
aaafe350bb65dfc24c2cdad4839059ac81899fbe,
e92a8e0c743f83552fac37ecf21e625ba3a4b11e.

I've kept&improved the tests though.

Fix a broken build for gcc <= 7.1

we need add a "this->" inside the lambda body to workaround it. Rewrite
it to normal for-range loop.

[DebugInstrRef] Create DBG_INSTR_REFs in SelectionDAG

When given the -experimental-debug-variable-locations option (via -Xclang
or to llc), have SelectionDAG generate DBG_INSTR_REF instructions instead
of DBG_VALUE. For now, this only happens in a limited circumstance: when
the value referred to is not a PHI and is defined in the current block.
Other situations introduce interesting problems, addresed in later patches.

Practically, this patch hooks into InstrEmitter and if it can find a
defining instruction for a value, gives it an instruction number, and
points the DBG_INSTR_REF at that <instr, operand> pair.

Differential Revision: https://reviews.llvm.org/D85747

[SystemZ] Bugfix in SystemZVectorConstantInfo

In order to correctly load an all-ones FP NaN value into a floating point
register with a VGBM, the analyzed 32/64 FP bits must first be shifted left
(into element 0 of the vector register).

SystemZVectorConstantInfo has so far relied on element replication which has
bypassed the need to do this shift, but now it is clear that this must be
done in order to handle NaNs.

Review: Ulrich Weigand

Differential Revision: https://reviews.llvm.org/D89389

[InstCombine] visitCallInst - retain undefs in vector funnel shift amounts

By always performing a modulo on the shift amount constants this was causing undef amounts being replaced with zero, meaning we were losing funnel shift by splat (with undef) patterns.

Tweaked the shift amount bounds check to support (passthrough) undefs, and use Constant::mergeUndefsWith to preserve the undefs after folding.

[mlir][Linalg] Add missing dependency

[mlir] expand the legal floating-point types in the LLVM IR dialect type check

This patch adds a couple missing LLVM IR dialect floating point types to
the legality check.

Reviewed By: ftynse

Differential Revision: https://reviews.llvm.org/D89350

Fix `-Wparentheses` warnings. NFC.

[libc++] Remove signal-based checkpoints in libc++ tests

While this adds some convenience to the test suite, it prevents the tests
using these checkpoints from being used on systems where signals are not
available, such as some embedded systems. It will also prevent these tests
from being constexpr-friendly once e.g. std::map is made constexpr, due
to the use of statics.

Instead, one can always use a debugger to figure out exactly where a
test is failing when that isn't clear from the log output without
checkpoints.

[flang] Rework host runtime folding and enable REAL(2) folding with it.

- Rework the host runtime table so that it is constexpr to avoid
  having to construct it and to store/propagate it.
- Make the interface simpler (remove many templates and a file)
- Enable 16bits float folding using 32bits float host runtime
- Move StaticMultimapView into its own header to use it for host
  folding

Reviewed By: klausler, PeteSteinfeld

Differential Revision: https://reviews.llvm.org/D88981

[SVE] Lower fixed length VECREDUCE_FADD operation

Differential Revision: https://reviews.llvm.org/D89263

[lldb] Remove bogus ProcessMonitor forward-decls

This class is not used in those files.

[lldb] Fix TestGdbRemoteMemoryAllocation on windows

It appears that memory allocation actually works on windows (but it was
not fully wired up before 2c4226f8).

[profile] Remove useless msync when dumping gcda files

Summary:
According the mmap man page (https://man7.org/linux/man-pages/man2/mmap.2.html) is only required to precisely control updates, so we can safely remove it.
Since gcda files are dumped just before to call exec** functions, dump need to be fast.
On my computer, Firefox built with --coverage needs ~1min40 to display something and in removing msync it needs ~8s.

Reviewers: void

Subscribers: #sanitizers, marco-c, sylvestre.ledru

Tags: #sanitizers

Differential Revision: https://reviews.llvm.org/D81060

[InstCombine] Add m_SpecificIntAllowUndef pattern matcher

m_SpecificInt doesn't accept undef elements in a vector splat value - tweak specific_intval to optionally allow undefs and add the m_SpecificIntAllowUndef variants.

Allows us to remove the m_APIntAllowUndef + comparison hack inside matchFunnelShift

Fix conjuntion of -Werror,-Wsuggest-override with google/benchmark

[mlir][vulkan-runner] Fix buffer usage flags

The buffers are used as source or destination of transfer commands
so always add VK_BUFFER_USAGE_TRANSFER_{DST,SRC}_BIT to their usage
flags.

Signed-off-by: Kevin Petit <kevin.petit@arm.com>

Fix an apparent typo. `assert()` must not contain side-effects. NFC.