Merge remote-tracking branch 'origin/users/ahmedbougacha/ptrauth-sign-constant' into users/ahmedbougacha/ptrauth-function-pointers

- Remove unneeded declarations.
- Fix includes.
- Use `llvm::to_underlying`.
- Fix variable names.
- Fix size and type of bit-fields.
- Add test case for `err_drv_ptrauth_not_supported`.

- test elf as well
- rename every variable.

Merge branch 'users/ahmedbougacha/ptrauth-string-discriminator' into users/ahmedbougacha/ptrauth-sign-constant

- add missing sema test
- also test ELF codegen for intrinsics
- various capitalization and type nits

Co-Authored-By: John McCall <rjmccall@apple.com>

This is constant-expression equivalent to __builtin_ptrauth_sign,
allowing its usage in global initializers, but requiring constant
pointers and discriminators.

Co-Authored-By: John McCall <rjmccall@apple.com>

This exposes the ABI-stable hash function that allows computing a 16-bit
discriminator from a constant string.

This allows manually matching the implicit string discriminators
computed in the ABI (e.g., from mangled names for vtable pointer/entry
signing), as well as enabling the use of interesting discriminators when
manually annotating specific pointers with the __ptrauth qualifier.

Co-Authored-By: John McCall <rjmccall@apple.com>

Based on the SipHash reference implementation:
  https://github.com/veorq/SipHash


which has very graciously been licensed under our llvm license
(Apache-2.0 WITH LLVM-exception) by Jean-Philippe Aumasson.

This lightly modifies it to fit into libSupport, and wraps it for the
two main interfaces we're interested in (16/64-bit).

This intentionally doesn't expose a raw interface beyond that to
encourage others to carefully consider their use.

The exact algorithm is the little-endian interpretation of the
non-doubled (i.e. 64-bit) result of applying a SipHash-2-4 using
a specific key value which can be found in the source.

By "stable" we mean that the result of this hash algorithm will the same
across different compiler versions and target platforms.

The 16-bit variant is used extensively for the AArch64 ptrauth ABI,
because AArch64 can efficiently load a 16-bit immediate into the high
bits of a register without disturbing the remainder of the value, which
serves as a nice blend operation.

16 bits is also sufficiently compact to not inflate a loader relocation.
We disallow zero to guarantee a different discriminator from the places
in the ABI that use a constant zero.

Co-Authored-By: John McCall <rjmccall@apple.com>

These are currently gated by __APPLE__; we can figure out a way to
define these on ELF targets as well, and maybe have them be defined
by clang itself, depending on ABI modes.

This is a second attempt to land #84501 which failed on several targets.

This patch adds the HAS_IEE754_FLOAT128 define which makes the check for
typedef'ing float128 more precise by checking whether __uint128_t is
available and checking if the host does not use __ibm128 which is
prevalent on power pc targets and replaces IEEE754 float128s.

FP typed atomic load/store coverage was mostly missing, especially for
half and bfloat.

This patch takes Richard's approach of no longer modeling dependent NTTP
arguments with TemplateParamObjectDecls. Clang used to do so, which left
behind a problem in that we might mess up dependent and non-dependent
arguments that boil down to the same canonical type because there's a
default argument on the NTTP.

The problem of "canonical expression" is still present because this
patch doesn't touch the profiling part. Namely, #92292 seems different.

Fixes https://github.com/llvm/llvm-project/issues/84052

There's some code in AggExprEmitter::VisitCXXParenListOrInitListExpr to
try to do early cleanup for GEPs for fields that aren't accessed. But
it's unlikely to actually save significant compile-time, and it's subtly
wrong in cases where EmitLValueForFieldInitialization() doesn't create a
GEP. So just delete the code.

Fixes #88077. Fixes #89547.

Opcodes are the same for these instructions in GFX11 and 12,
hence this typo has no functional impact.

Reverts llvm/llvm-project#86223

windows pre-merge is broken.

Instead of using FOO_TEST_DEPS global variables that don't get updated
properly from subdirectories, use targets to propagate the dependencies
across directories.

A while back, the cxx_under_test Lit parameter was removed. This patch
reintroduces a Lit parameter called "compiler" which controls the value
of the %{cxx} substitution used in the test suite.

To run the test suite with a different compiler, one can now pass
--param compiler=<path>.

In essence, this header has always been related to configuration of
the library but we didn't want to put it inside <__config> due to
complexity reasons. Now that we have sub-headers in <__config>, we
can move <__availability> to it and stop including it everywhere since
we already obtain the required macros via <__config>.

This reverts commit 0380044e.

While I figure out some mysterious CMake error.

Since we have already addressed the LWG issue, this PR marks LWG3951 as
implemented.

Signed-off-by: yronglin <yronglin777@gmail.com>
Co-authored-by: A. Jiang <de34@live.cn>

The DominatorTree can be reused if no CFG changes.

There was a Darwin only use of setupterm (under USE_SETUPTERM_WORKAROUND)
that required libcurses.dylib.  That was added to the main build, but
not to the unittest.

Without this change, the build will fail like so:

llvm-project/lld/MachO/ObjC.cpp:1387:75: error: ISO C++20 considers use of overloaded operator '==' (with operand types 'ObjcCategoryMerger::PointerListInfo' and 'ObjcCategoryMerger::PointerListInfo') to be ambiguous despite there being a unique best viable function [-Werror,-Wambiguous-reversed-operator]
 1387 |       parseProtocolListInfo(classIsec, roClassLayout.baseProtocolsOffset) ==
      |       ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ^
 1388 |           parseProtocolListInfo(metaIsec, roClassLayout.baseProtocolsOffset) &&
      |           ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
include/assert.h:100:27: note: expanded from macro 'assert'
  100 |      (static_cast <bool> (expr)                                         \
      |                           ^~~~
llvm-project/lld/MachO/ObjC.cpp:391:17: note: ambiguity is between a regular call to this operator and a call with the argument order reversed
  391 |     inline bool operator==(const PointerListInfo &cmp) {
      |                 ^
llvm-project/lld/MachO/ObjC.cpp:391:17: note: mark 'operator==' as const or add a matching 'operator!=' to resolve the ambiguity
1 error generated.

Tighten the verifier for arith cast ops to disallow changing tensor
dimensions, e.g., static to dynamic. After this change:
* `arith.cast_op %x : tensor<4xi32> to tensor<4xf32>` remains valid
* `arith.cast_op %x : tensor<4xi32> to tensor<?xf32>` becomes invalid
* `arith.cast_op %x : tensor<?xi32> to tensor<4xf32>` becomes invalid

This is mostly to simplify the op semantics. See the discussion thread
for more context:
https://discourse.llvm.org/t/rfc-remove-arith-math-ops-on-tensors/74357/63.

Testing github actions is such a pain. I swear it should match now.

This was added in #93586 but caused a compilation warning and is not
used anyway.

This defines a new kind of IR Constant that represents a ptrauth signed
pointer, as used in AArch64 PAuth.

It allows representing most kinds of signed pointer constants used thus
far in the llvm ptrauth implementations, notably those used in the
Darwin and ELF ABIs being implemented for c/c++.  These signed pointer
constants are then lowered to ELF/MachO relocations.

These can be simply thought of as a constant `llvm.ptrauth.sign`, with
the interesting addition of discriminator computation: the `ptrauth`
constant can also represent a combined blend, when both address and
integer discriminator operands are used.  Both operands are otherwise
optional, with default values 0/null.

This reuses most of the code that was created for f32x4 and f64x2 binary
instructions and tries to follow how they were implemented.

add/sub/mul/div - use regular LL instructions
min/max - use the minimum/maximum intrinsic, and also have builtins
pmin/pmax - use the wasm.pmax/pmin intrinsics and also have builtins

Specified at:

https://github.com/WebAssembly/half-precision/blob/29a9b9462c9285d4ccc1a5dc39214ddfd1892658/proposals/half-precision/Overview.md

This adds `-wasm-enable-exnref`, which will enable the new EH
instructions using `exnref` (adopted in Oct 2023 CG meeting):
https://github.com/WebAssembly/exception-handling/blob/main/proposals/exception-handling/Exceptions.md
This option should be used with `-wasm-enable-eh`.