BOLT currently assumes (and asserts) that no two relocations can share
the same offset. Although this is true in most cases, ELF has a feature
called (not sure if this is an official term) composed relocations [1]
where multiple relocations at the same offset are combined to produce a
single value.

For example, to support label subtraction (a - b) on RISC-V, two
relocations are emitted at the same offset:
- R_RISCV_ADD32 a + 0
- R_RISCV_SUB32 b + 0
which, when combined, will produce the value of (a - b).

To support this in BOLT, first, RelocationSetType in BinarySection is
changed to be a multiset in order to allow it to store multiple
relocations at the same offset.

Next, Relocation::emit() is changed to receive an iterator pair of
relocations. In most cases, these will point to a single relocation in
which case its behavior is unaltered by this patch. For composed
relocations, they should point to all relocations at the same offset and
the following happens:
- A new method Relocation::createExpr() is called for every relocation.
  This method is essentially the same as the original emit() except that
  it returns the MCExpr without emitting it.
- The MCExprs of relocations i and i+1 are combined using the opcode
  returned by the new method Relocation::getComposeOpcodeFor().
- After combining all MCExprs, the last one is emitted.

Note that in the current patch, getComposeOpcodeFor() simply calls
llvm_unreachable() since none of the current targets use composed
relocations. This will change once the RISC-V target lands.

Finally, BinarySection::emitAsData() is updated to group relocations by
offset and emit them all at once.

Note that this means composed relocations are only supported in data
sections. Since this is the only place they seem to be used in RISC-V, I
believe it's reasonable to only support them there for now to avoid
further code complexity.

[1]: https://www.sco.com/developers/gabi/latest/ch4.reloc.html

Reviewed By: rafauler

Differential Revision: https://reviews.llvm.org/D146546

Like yocto, zepto, zetta, and yotta. The new prefixes quecto, ronto,
ronna, and quetta can't be implemented in a intmax_t. So their
implementation does nothing.

Implements
- P2734R0 Adding the new SI prefixes

Depends on D153192

Reviewed By: #libc, philnik

Differential Revision: https://reviews.llvm.org/D153200

Implements part of:
- P1614R2 The Mothership has Landed

Reviewed By: #libc, H-G-Hristov, philnik

Differential Revision: https://reviews.llvm.org/D153222

This FTM was introduced in
  P0553R4 Bit operations

Which has been implemented since libc++ 9.

This was noticed while working on D153192.

Reviewed By: #libc, philnik

Differential Revision: https://reviews.llvm.org/D153225

lld/test/Unit/lit.site.cfg.py.in got cleaned up in the reland.

This updates:
- The status tables
- Feature test macros
- New headers for modules
The latter avoids forgetting about modules when implementing the feature
in a new header.

Reviewed By: #libc, philnik

Differential Revision: https://reviews.llvm.org/D153192

This reverts commit aabea3d3.

That commit had mistakenly squashed spurious changes in.

The lld CL relanded in 6f2e92c1.

This reverts commit d76b37e6.

For both CodeGen and CostModelling, this adds extran testing for the new
lvm.vector.reduce.fmaximum and lvm.vector.reduce.fminimum intrinsics, as well
as making sure there is test coverage for all the various cases.

Patch eece6ba2 changed the src1 type of v_ldexp_f16 from i32 to
i16. Though semantically src1 is an i16, the hardware reads this operand as an
f16 type, which primarily enables floating point inline constants.
Therefore this patch changes the operand type to f16. It maintains the
current behavior where floating point source modifiers are not allowed
on src1. SDWA sext modifier continues to be allowed.
The test asm and disasm test changes in eece6ba2 are reverted,
because the floating point inline constants are allowed.

Reviewed By: arsenm

Differential Revision: https://reviews.llvm.org/D153169

RFC https://discourse.llvm.org/t/rfc-dwarfdebug-fix-and-improve-handling-imported-entities-types-and-static-local-in-subprogram-and-lexical-block-scopes/68544



Similar to imported declarations, the patch tracks function-local types in
DISubprogram's 'retainedNodes' field. DwarfDebug is adjusted in accordance with
the aforementioned metadata change and provided a support of function-local
types scoped within a lexical block.

The patch assumes that DICompileUnit's 'enums field' no longer tracks local
types and DwarfDebug would assert if any locally-scoped types get placed there.

Authored-by: Kristina Bessonova <kbessonova@accesssoftek.com>

Differential Revision: https://reviews.llvm.org/D144006

Depends on D144005

In D152070 we added many new intrinsic types required for the RISC-V
Vector Extension.

This was crashing when loading the AST as those types are intrinsically
added to the AST (they don't come from the disk).

The total number required now by clang exceeds 400 so increasing the
value to 500 solves the problem. This value was already increased in
D92715 but I assume this has some impact on the on-disk format.

Also add a static assert to avoid this happening again in the future.

Differential Revision: https://reviews.llvm.org/D153111

Add unit test triggering an assertion with abfeda5a.

Restriction to ModuleOp is ancient and unnecessarily restrictive.

This makes it such that new.cpp contains only the definitions of
operator new and operator delete, like its libc++abi counterpart.

Differential Revision: https://reviews.llvm.org/D153136

Avoid inserting the freeze if not necessary, as this allows LVI
to continue reasoning about the expression.

After each iteration of the function specializer, constant stack values
are promoted to constant globals in order to enable recursive function
specialization. This should also be done once before running the
specializer. Enables specialization of _QMbrute_forcePdigits_2 from
SPEC2017:548.exchange2_r.

Differential Revision: https://reviews.llvm.org/D152799

This patch implements the "__kmp_print_tdg_dot" function, that prints a task dependency graph into a dot file containing the tasks and their dependencies.

It is activated through a new environment variable "KMP_TDG_DOT"

Reviewed By: tianshilei1992

Differential Revision: https://reviews.llvm.org/D150962

SplitBlockAndInsertIfThen utility creates two new blocks,
they're called ThenBlock and Tail (true and false destinations of a conditional
branch correspondingly). The function has a bool parameter Unreachable,
and if it's set, then ThenBlock is terminated with an unreachable.
At the end of the function the new blocks are added to the loop of the split
block. However, in case ThenBlock is terminated with an unreachable,
it cannot belong to any loop.

Differential Revision: https://reviews.llvm.org/D152434

The LLVM comdat operation specifies how to deduplicate globals with the
same key in two different object files. This is necessary on Windows
where e.g. two object files with linkonce globals will not link unless
a comdat for those globals is specified. It is also supported in the ELF
format.

Differential Revision: https://reviews.llvm.org/D150796

Implement XCVbitmanip intrinsics for CV32E40P according to the specification.

This commit is part of a patch-set to upstream the 7 vendor specific extensions of CV32E40P.

Contributors: @CharKeaney, @jeremybennett, @lewis-revill, @liaolucy, @simoncook, @xmj.

Spec: https://github.com/openhwgroup/cv32e40p/blob/62bec66b36182215e18c9cf10f723567e23878e9/docs/source/instruction_set_extensions.rst

Reviewed By: craig.topper

Differential Revision: https://reviews.llvm.org/D152915

The operations.cpp file contained the implementation of a ton of
functionality unrelated to just the filesystem operations, and
filesystem_common.h contained a lot of unrelated functionality as well.

Splitting this up into more files will make it possible in the future
to support parts of <filesystem> (e.g. path) on systems where there is
no notion of a filesystem.

Differential Revision: https://reviews.llvm.org/D152377

A few tests were also straightforward to translate to SFINAE tests
instead, so in a few cases I did that and removed the .fail.cpp test
entirely.

Differential Revision: https://reviews.llvm.org/D153149

For consistency with other algorithms.

Differential Revision: https://reviews.llvm.org/D153141

These are leftover hacks from using asm declaratios to access
intrinsics.

Key changes:
  - Refactor the createTargetData function to make use of the emitOffloadingArrays and emitOffloadingArraysArgument functions to generate code.
  - Added a new emitIfClause helper function to allow handling if clauses in a similar fashion to Clang.
  - Updated the MLIR side of code to account for changes to createTargetData.

Depends on D149872

Reviewed By: jdoerfert

Differential Revision: https://reviews.llvm.org/D146557

This register is used as the pointer to the current thread
local storage block and is read from NT_ARM_TLS on Linux.

Though tpidr will be present on all AArch64 Linux, I am soon
going to add a second register tpidr2 to this set.

tpidr is only present when SME is implemented, therefore the
NT_ARM_TLS set will change size. This is why I've added this
as a dynamic register set to save changes later.

Reviewed By: omjavaid

Differential Revision: https://reviews.llvm.org/D152516

This reverts commit aa495214.

As discussed in https://github.com/llvm/llvm-project/issues/53475 this patch
allows for using LLD-as-a-lib. It also lets clients link only the drivers that
they want (see unit tests).

This also adds the unit test infra as in the other LLVM projects. Among the
test coverage, I've added the original issue from @krzysz00, see:
https://github.com/ROCmSoftwarePlatform/D108850-lld-bug-reproduction

Important note: this doesn't allow (yet) linking in parallel. This will come a
bit later hopefully, in subsequent patches, for COFF at least.

Differential revision: https://reviews.llvm.org/D119049

The wrapper, as most of compiler-generated functions, are intended to serve the
IR for the current module. The safest linkage is to keep these private to avoid
any possible collision with other modules.

Differential Revision: https://reviews.llvm.org/D153255

This was a spurious closing parenthese.

The ConstantRange specifies the range of the scalar elements in the
vector. When converting into a Constant, we need to create a vector
splat with the correct type. For that purpose, pass in the expected
type for the constant.

Fixes https://github.com/llvm/llvm-project/issues/63380.

https://github.com/llvm/llvm-project/issues/62750

I setup a simple test with a large .so (~100MiB) that was only present on the target machine
but not present on the local machine, and ran a lldb server on the target and connectd to it.

LLDB properly downloads the file from the remote, but it does so at a very slow speed, even over a hardwired 1Gbps connection!

Increasing the buffer size for downloading these helps quite a bit.

Test setup:

```
$ cat gen.py
print('const char* hugeglobal = ')

for _ in range(1000*500):
    print('  "' + '1234'*50 + '"')

print(';')
print('const char* mystring() { return hugeglobal; }')
$ gen.py > huge.c
$ mkdir libdir
$ gcc -fPIC huge.c -Wl,-soname,libhuge.so -o libdir/libhuge.so -shared
$ cat test.c
#include <string.h>
#include <stdio.h>
extern const char* mystring();
int main() {
        printf("%d\n", strlen(mystring()));
}
$ gcc test.c -L libdir -l huge -Wl,-rpath='$ORIGIN' -o test
$ rsync -a libdir remote:~/
$ ssh remote bash -c "cd ~/libdir && /llvm/buildr/bin/lldb-server platform --server --listen '*:1234'"
```

in another terminal

```
$ rm -rf ~/.lldb # clear cache
$ cat connect.lldb
platform select remote-linux
platform connect connect://10.0.0.14:1234
file test
b main
r
image list
c
q
$ time /llvm/buildr/bin/lldb --source connect.lldb
```

Times with various buffer sizes:

1kiB (current): ~22s
8kiB: ~8s
16kiB: ~4s
32kiB: ~3.5s
64kiB: ~2.8s
128kiB: ~2.6s
256kiB: ~2.1s
512kiB: ~2.1s
1MiB: ~2.1s
2MiB: ~2.1s

I choose 512kiB from this list as it seems to be the place where the returns start diminishing and still isn't that much memory

My  understanding of how this makes such a difference is ReadFile issues a request for each call, and larger buffer means less round trip times. The "ideal" situation is ReadFile() being async and being able to issue multiple of these, but that is much more work for probably little gains.

NOTE: this is my first contribution, so wasn't sure who to choose as a reviewer. Greg Clayton seems to be the most appropriate of those in CODE_OWNERS.txt

Reviewed By: clayborg, jasonmolenda

Differential Revision: https://reviews.llvm.org/D153060