[mlir][tosa] Simplify pad shape inference and verification (#233064)
Treat constant padding amounts as ordinary integers during shape
inference. Remove the example assigning a dynamic-padding meaning to
negative values.
Keep PadOp verification local to operand and result types. Check padding
length through its shape type and drop checks of constant operand
contents and derived output extents.
Assisted-by: Codex
[MLIR] Default PDL off for dependency-only builds (#233108)
Default PDL support in PatternMatch to off whenever MLIR is configured
only as a dependency. Keep the existing default for explicitly enabled
MLIR builds and preserve user-provided PDL settings. This speeds up
clang build with CIR enabled.
Assisted-by: Codex
[LangRef] Relax the LLVM IR data race definition
The current LangRef rules categorize some surprising (to me) cases as data
races (more specifically: they define loads to return `undef` in surprising
situations).
At the core of the problem is the requirement that, if a read R may see more
than one write, R and all the writes it may see must be atomic, otherwise R
returns `undef`. That means that, if an atomic write W and an atomic read R
execute concurrently, a non-atomic write W' that happens-before both of them
causes R to return `undef`. We get that situation if W' initializes the
location in a sequential portion of the program, followed by proper
synchronization before a parallel portion of the program where W and R take
place.
Some litmus tests for the problem:
1. A non-atomic store that happens-before an atomic store and an atomic load:
```
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[InstCombine] Fold exp2(uitofp x) to ldexp(1.0, x) with ninf
`exp2(uitofp iN x) -> ldexp(1.0, zext x)` currently requires N to be
narrower than `int`, because `ldexp` takes a signed `int` exponent.
When N equals the width of `int`, the fold is still correct under `ninf`.
Every LLVM FP type has $E_{\max} \le 16383 < 2^{15} \le 2^{N-1}$, so:
- $x < 2^{N-1}$: signed and unsigned $x$ agree, so $\operatorname{ldexp}(1.0, x) = 2^{x} = \operatorname{exp2}(x)$.
- $x \ge 2^{N-1}$: $\operatorname{exp2}(x) \ge 2^{2^{N-1}} > 2^{E_{\max}}$ overflows to $+\infty$, which is poison under `ninf`.
This only applies to the intrinsic, since the `exp2` libcall may set
`errno` on overflow.
This also enables `pow(2.0, uitofp x) -> ldexp` via the existing
`pow(2^n, x) -> exp2(n * x)` fold.
[InstCombine] Pre-commit tests for exp2(uitofp) -> ldexp with ninf. NFC (#227377)
Add baseline tests for folding `exp2(uitofp iN x)` to `ldexp(1.0, x)`
when N equals the width of C int, including negative tests (no ninf,
source wider than int, libcall).
[CIR] Lower array globals with many trailing zeros as packed structs (#232835)
A global such as `T x[NUM_ELEMENTS] = {1}` reaches LLVM lowering as a
`#cir.const_array` with one explicit element and NUM_ELEMENTS trailing
zeros.
When NUM_ELEMENTS is large that lowering becomes impractical and slow.
This PR fixes such cases by following OG:
1. when there are 8 or more explicit elements of the same type,
the array is lowered as a packed struct with a trailing zero-initialized
array.
2. When an array initializer ends in 8 or more zeros,
the array is lowered as a packed struct with the explicit elements
followed by one zero-initialized array.
`cxx11-initializer-aggregate.cpp` earlier the compilation was
not completing on my system. Now the test compiles
with -fclangir in about 0.1s, and its huge-array globals match classic
codegen. Several
existing tests now produce the same output as classic codegen for
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[libc] Use a syscall wrapper for `sched_get_priority_min` (#233409)
This PR move `sched_get_priority_min` behind the centralized syscall
wrappers, following `libc/docs/dev/syscall_wrapper_refactor.md`.
[ClangLinkerWrapper] Emit extra job to generate -save-temps assembly (#224446)
Summary:
This is an oft-requested feature and unfortunately cannot be done
easily. The approach is just to make a redundant job that does the same
handling, but emits an `--lto-emit-asm` job in the background. Ideally
these get enough parallelism that the total compile time doesn't change
much.
I cannot find a cleaner way to return the 'old driver behavior' for
emitting assembly as was requested. THe LTO pipeline is not built to
generate intermediate files like this, and running this *then* consuming
the assembly on output would break thinLTO, partitioned LTO, or future
object linking.
[libc] Move setxid entrypoints to experimental (#233416)
POSIX requires functions that change credentials (setuid, setgid,
setreuid, setregid, setgroups, initgroups) to affect all threads in a
process. On Linux, the underlying kernel syscalls operate per-thread.
Propagating these changes across all threads requires setxid signal
machinery, which we do not have yet.
Move these entry points to experimental on Linux targets and add a TODO
to their implementations.
Assisted-by: Gemini
[lldb][test] Skip TestMultithreadedStopHook.py on all Linux (#233422)
Failures have been reported in x86_64 premerge jobs: ERROR: test
(TestMultithreadedStopHook.MultithreadedStopHookTestCase.test)
----------------------------------------------------------------------
Traceback (most recent call last):
File
"/home/gha/actions-runner/_work/llvm-project/llvm-project/lldb/packages/Python/lldbsuite/test/decorators.py",
line 221, in wrapper
return func(*args, **kwargs)
File
"/home/gha/actions-runner/_work/llvm-project/llvm-project/lldb/test/API/api/multithreaded/stop_hook/TestMultithreadedStopHook.py",
line 19, in test
self.buildAndRunDriver("driver.cpp test_stop-hook.cpp", "inferior.cpp")
~~~~~~~~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File
"/home/gha/actions-runner/_work/llvm-project/llvm-project/lldb/packages/Python/lldbsuite/test/lldbtest.py",
line 1877, in buildAndRunDriver
check_call(
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makefs/zfs: count "." in the link count and size of dataset roots
The root directory of a dataset is populated from an fsnode that is the
"." entry of the staging directory, and its children are the siblings of
that node, so the loop that computes the link count and the size of the
directory (which expects "." among the children, as the nodes of the
other directories have) never counts it. The link count of the root of
every dataset is one less than it should be (1 for an empty dataset
instead of 2, 19 instead of 20 for a root with 18 subdirectories), and
so is its size.
fts(3) trusts the link count of the directories of ZFS when called with
FTS_NOSTAT and FTS_PHYSICAL: it stops looking for subdirectories once it
has seen as many as the link count says, and does not descend into the
ones it did not look at. As a result find(1), and rm(1) when it does
not need to stat the entries, silently skip directories of a pool made
by makefs. On a root filesystem made by makefs, find / does not list
/etc at all.
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[flang] Avoid crash on conflicting BIND(C) declaration (#231816)
Fixes #229729
This PR addresses a Flang crash that occurs when a scalar variable with
the BIND(C) attribute conflicts with an existing derived-type
declaration.
