Precommit tests for D115922.

Differential Revision: https://reviews.llvm.org/D116013

- Improve extension description.
- Rename "What is DWARF?" section to better reflect what it is
  describing.

Reviewed By: kzhuravl

Differential Revision: https://reviews.llvm.org/D116077

Matteo Croce reported a bpf backend fatal error in
https://github.com/llvm/llvm-project/issues/52779

A simplified case looks like:
  $ cat bug.c
  extern int do_smth(int);
  int test() {
    return __builtin_btf_type_id(*(typeof(do_smth) *)do_smth, 1);
  }
  $ clang -target bpf -O2 -g -c bug.c
  fatal error: error in backend: Empty type name for BTF_TYPE_ID_REMOTE reloc
  ...

The reason for the fatal error is that the relocation is against
a DISubroutineType like type 13 below:
  !10 = !DIBasicType(name: "int", size: 32, encoding: DW_ATE_signed)
  !11 = !{}
  !12 = !DILocation(line: 3, column: 10, scope: !7)
  !13 = !DISubroutineType(types: !14)
  !14 = !{!10, !10}

The DISubroutineType doesn't have a name and there is no way for
downstream bpfloader/kernel to do proper relocation for it.

But we can improve error message to be more specific for this case.
The patch improved the error message to be:
  fatal error: error in backend: SubroutineType not supported for BTF_TYPE_ID_REMOTE reloc

Differential Revision: https://reviews.llvm.org/D116063

Summary: When disassembling, symbolize a branch target operand
to print a label instead of a real address.

Reviewed By: shchenz

Differential Revision: https://reviews.llvm.org/D114492

Fix mismatched-new-delete in memprof test_new_load_store.cpp and test_terse.cpp

Reviewed By: snehasish

Differential Revision: https://reviews.llvm.org/D116024

This also makes the sanitizer_stoptheworld_test cross-platform by using the STL, rather than pthread.

Reviewed By: vitalybuka

Differential Revision: https://reviews.llvm.org/D115204

[LTO] Fix incomplete optimization remarks for dead functions when PreOptModuleHook or PostInternalizeModuleHook is defined

In 20a895c4, we introduce `finalizeOptimizationRemarks()` to make sure we flush the diagnostic remarks file in case the linker doesn't call the global destructors before exiting.
In https://reviews.llvm.org/D73597, we add optimization remarks for removed functions for debugging or for detecting dead code.
But there is a case, if PreOptModuleHook or PostInternalizeModuleHook is defined (e.g. `--plugin-opt=emit-llvm` is passed to linker), we do not call `finalizeOptimizationRemarks()`, therefore we will get an incomplete optimization remarks file.
This patch make sure we flush the diagnostic remarks file when PreOptModuleHook or PostInternalizeModuleHook is defined.

Reviewed By: tejohnson, MaskRay

Differential Revision: https://reviews.llvm.org/D115417

All platforms which can start the thread should stop it as well.

This is a reapply of a8a51fe5, which was reverted in 1ba99e due to a failing compiler-rt test.   That test was a false positive because it was checking asan failures not accounting for the fact the call could be validly optimized out.  I hopefully managed to stablize that test in 9b955f.  (That's a speculative fix due to disk consumption needed to build compiler-rt tests locally being absurd.)

Original commit message follows..

The majority of this change is sinking logic from instcombine into MemoryLocation such that it can be generically reused. If we have a call with a single analyzable write to an argument, we can treat that as-if it were a store of unknown size.

Merging the code in this was unblocks DSE in the store to dead memory code paths. In theory, it should also enable classic DSE of such calls, but the code appears to not know how to use object sizes to refine unknown access bounds (yet).

In addition, this does make the isAllocRemovable path slightly stronger by reusing the libfunc and additional intrinsics bits which are already in getForDest.

Differential Revision: https://reviews.llvm.org/D115904

This attempts to adjust the test to still exercise the expected codepath after D115904.  This test is fundementally rather fragile.

Unfortunately, I have not been able to confirm this workaround either does, or does not, work.  Attempting check-all with compiler-rt blows through an additional 30GB of disk space so my build config which exceeds my local disk space.

This reverts commit 75a5eaf7.

Remove global constructor which may or may not be needed for Android,
at it breaks Darwin now.

Reviewed By: lattner, kristof.beyls

Differential Revision: https://reviews.llvm.org/D113427

One of the uses of `LTOCodeGenerator` is to take it as a middle+back end. Sometimes
it is very helpful to access, especially get information from the optimized module.
If the information can be changed in optimization, it cannot be get before the
module is added to `LTOCodeGenerator`. This patch adds a function
`LTOCodeGenerator::getMergedModule` to access the `MergedModule`.

Reviewed By: steven_wu

Differential Revision: https://reviews.llvm.org/D114201

Differential Revision: https://reviews.llvm.org/D115956

These actions should only be used for adjusting the register types
(and the memory type as needed to satisfy the register
type). Unaligned accesses should be split as a type of lowering.

This has the effect of improving the code in many cases since now we
produce zextloads instead of separate loads with ands. The load/store
legality rules still seem far more complicated than necessary though.

The test would crash because a non-instruction negate op made it in here.

Fixes #51506

jonathan2251.github.com/lbd/ is 404. Update the URL to .io one according
to https://github.com/Jonathan2251/lbd/blob/master/README.md.

Unit tests are not getting built as part of bazel runs.

Reviewed By: mehdi_amini, GMNGeoffrey

Differential Revision: https://reviews.llvm.org/D116046

And incorrect command option description for `-gen-pass-decls`.

Control-Flow Integrity (CFI) replaces references to address-taken
functions with pointers to the CFI jump table. This is a problem
for low-level code, such as operating system kernels, which may
need the address of an actual function body without the jump table
indirection.

This change adds the __builtin_function_start() builtin, which
accepts an argument that can be constant-evaluated to a function,
and returns the address of the function body.

Link: https://github.com/ClangBuiltLinux/linux/issues/1353

Depends on D108478

Reviewed By: pcc, rjmccall

Differential Revision: https://reviews.llvm.org/D108479

With Control-Flow Integrity (CFI), the LowerTypeTests pass replaces
function references with CFI jump table references, which is a problem
for low-level code that needs the address of the actual function body.

For example, in the Linux kernel, the code that sets up interrupt
handlers needs to take the address of the interrupt handler function
instead of the CFI jump table, as the jump table may not even be mapped
into memory when an interrupt is triggered.

This change adds the no_cfi constant type, which wraps function
references in a value that LowerTypeTestsModule::replaceCfiUses does not
replace.

Link: https://github.com/ClangBuiltLinux/linux/issues/1353

Reviewed By: nickdesaulniers, pcc

Differential Revision: https://reviews.llvm.org/D108478

Reviewed By: ftynse

Differential Revision: https://reviews.llvm.org/D115956

This prevents "warning C4551: function call missing argument list"

Currently the behavior with relative paths is pretty broken. It differs
between external shell and internal shell because the path resolution
is done with a different working directory. With the internal shell,
it's resolved relative to the directory from which lit is executed,
whereas with the external shell it's resolved relative to where the
test case is executed. To make matters worse, using the internal shell
the filepath to binaries looked up with `which` is returned relative
to the directory from which lit is executed, but then executed from
the test execution directory. That means that relative paths with the
internal shell give a `[Errno 2] No such file or directory` error
instead of the expected `command not found`.

To address these issues this patch makes lit interpret relative paths
as relative to the directory from which lit was invoked and modifies
`which` to return absolute paths, matching the behavior of its
namesake unix function.

See https://groups.google.com/g/llvm-dev/c/KzMWlOXR98Y/m/QJoqn0U5HAAJ

Reviewed By: yln

Differential Revision: https://reviews.llvm.org/D115486

This patch allows the user to request all resources of a particular
layer (or core-attribute). The syntax of KMP_HW_SUBSET is modified
so the number of units requested is optional or can be replaced with an
'*' character.

e.g., KMP_HW_SUBSET=c:intel_atom@3 will use all the cores after offset 3
e.g., KMP_HW_SUBSET=*c:intel_core will use all the big cores
e.g., KMP_HW_SUBSET=*s,*c,1t will use all the sockets, all cores per
      each socket and 1 thread per core.

Differential Revision: https://reviews.llvm.org/D115826

Test a range of acceptable forms of co_max calls, including
combinations of keyword and non-keyword actual arguments of
numeric types.  Also test that several invalid forms of
co_max call generate the correct error messages.

Reviewed By: ktras

Differential Revision: https://reviews.llvm.org/D113083

This reverts 3816c53f and removes follow-up
fixups.

The original intention was to show error earlier (posix_fallocate time) than
later for ld.lld but it appears to cause some problems which make it not free.

* FreeBSD ZFS: EINVAL, not too bad.
* FreeBSD UFS: according to khng "devastatingly slow on freebsd because UFS on freebsd does not have preallocation support like illumos. It zero-fills."
* NetBSD: maybe EOPNOTSUPP
* Linux tmpfs: unless tmpfs is set up to use huge pages (requires CONFIG_TRANSPARENT_HUGE_PAGECACHE=y), I can consistently demonstrate ~300ms delay for a 1.4GiB output.
* Linux ext4: I don't measure any benefit, either backed by a hard disk or by a file in tmpfs.
* The current code organization of `defined(HAVE_POSIX_FALLOCATE)` costs us a macro dispatch for AIX.

I think we should just remove it. I think if posix_fallocate ever finds demonstrable benefit,
it is likely Linux specific and will not need HAVE_PO...

Test various acceptable forms of co_min calls, including
combinations of keyword and non-keyword actual arguments of
integer, real, and character types.  Also test that several
invalid forms of co_min call generate the correct error messages.

Reviewed By: ktras

Differential Revision: https://reviews.llvm.org/D113077

Differential Revision: https://reviews.llvm.org/D115930

This reverts commit 93d79cac.

This patch seems to break
llvm/test/CodeGen/ARM/constant-islands-cfg.mir under asan.

writeSections is typically a bottleneck.
This was used to track down the following bottlenecks:

* Output section .rela.dyn (9115d751)
* Output section .debug_str (3aae04c7)
* posix_fallocate is slow for Linux tmpfs: D115957

Reviewed By: ikudrin

Differential Revision: https://reviews.llvm.org/D115984

Test a range of acceptable forms of co_reduce calls, including
combinations of keyword and non-keyword actual arguments of
numeric types.  Also test that several invalid forms of
co_reduce call generate the correct error messages.

Reviewed By: kiranchandramohan, ktras, ekieri

Differential Revision: https://reviews.llvm.org/D113086

When P0883R2 was initially implemented in D103769 #pragma clang deprecated didn't exist yet.
We also forgot to cleanup usages in libc++ itself.

This takes care of both.

Differential Revision: https://reviews.llvm.org/D115995