This updates all the non-runtime project release notes to use the
version number from CMake instead of the hard-coded version numbers
in conf.py.
It also hides warnings about pre-releases when the git suffix
is dropped from the LLVM version in CMake.
Reviewed By: MaskRay
Differential Revision: https://reviews.llvm.org/D112181
Generalize D99629 for ELF. A default visibility non-local symbol is preemptible
in a -shared link. `isInterposable` is an insufficient condition.
Moreover, a non-preemptible alias may be referenced in a sub constant expression
which intends to lower to a PC-relative relocation. Replacing the alias with a
preemptible aliasee may introduce a linker error.
Respect dso_preemptable and suppress optimization to fix the abose issues. With
the change, `alias = 345` will not be rewritten to use aliasee in a `-fpic`
compile.
```
int aliasee;
extern int alias __attribute__((alias("aliasee"), visibility("hidden")));
void foo() { alias = 345; } // intended to access the local copy
```
While here, refine the condition for the alias as well.
For some binary formats like COFF, `isInterposable` is a sufficient condition.
But I think canonicalization for the changed case has little advantage, so I
don't bother to add the `Triple(M.getTargetTriple()).isOSBinFormatELF()` or
`getPICLevel/getPIELevel` complexity.
For instrumentations, it's recommended not to create aliases that refer to
globals that have a weak linkage or is preemptible. However, the following is
supported and the IR needs to handle such cases.
```
int aliasee __attribute__((weak));
extern int alias __attribute__((alias("aliasee")));
```
There are other places where GlobalAlias isInterposable usage may need to be
fixed.
Reviewed By: rnk
Differential Revision: https://reviews.llvm.org/D107249
In GNU ar (since 2008), the modifier 'T' means creating a thin archive.
In many other ar implementations (FreeBSD, macOS, elfutils, etc), -T
means "allow filename truncation of extracted files", as specified by
X/Open System Interface.
For portability, 'T' with thin archive semantics should be avoided.
See https://sourceware.org/bugzilla/show_bug.cgi?id=28759 binutils 2.38
will deprecate 'T' (without diagnostic) and add --thin.
Reviewed By: jhenderson
Differential Revision: https://reviews.llvm.org/D116979
Summary:
Add code object v5 support (deafult is still v4)
Generate metadata for implicit kernel args for the new ABI
Set the metadata version to be 1.2
Reviewers:
t-tye, b-sumner, arsenm, and bcahoon
Fixes:
SWDEV-307188, SWDEV-307189
Differential Revision:
https://reviews.llvm.org/D118272
Compact Unwind is a subsection, but that was lost in rGff9feeb520a32d076c3095468208ae116c428285
Reviewed By: void
Differential Revision: https://reviews.llvm.org/D118499
As raised here: https://lists.llvm.org/pipermail/llvm-dev/2021-November/153881.html
Now that VS2022 is on general release, LLVM is expected to build on VS2017, VS2019 and VS2022, which is proving hazardous to maintain due to changes in behaviour including preprocessor and constexpr changes. Plus of the few developers that work with VS, many have already moved to VS2019/22.
This patch proposes to raise the minimum supported version to VS2019 (16.x) - I've made the hard limit 16.0 or later, with the soft limit VS2019 16.7 - older versions of VS2019 are "allowed" (at your own risk) via the LLVM_FORCE_USE_OLD_TOOLCHAIN cmake flag.
Differential Revision: https://reviews.llvm.org/D114639
The LLVM Libc project is no longer just a proposal and should have
a webpage tracking the status of the project. This changes
puts the pieces into the right place so that the webpage can be
created.
Reviewed By: sivachandra
Differential Revision: https://reviews.llvm.org/D117436
Currently, the clang.arc.attachedcall bundle takes an optional function
argument. Depending on whether the argument is present, calls with this
bundle have the following semantics:
- on x86, with the argument present, the call is lowered to:
call _target
mov rax, rdi
call _objc_retainAutoreleasedReturnValue
- on AArch64, without the argument, the call is lowered to:
bl _target
mov x29, x29
and the objc runtime call is expected to be emitted separately.
That's because, on x86, the objc runtime checks for both the mov and
the call on x86, and treats the combination as the ARC autorelease elision
marker.
But on AArch64, it only checks for the dedicated NOP marker, as that's
historically been sufficiently unique. Thanks to that, the runtime call
wasn't required to be adjacent to the NOP marker, so it wasn't emitted
as part of the bundle sequence.
This patch unifies both architectures: on AArch64, we now emit all
3 instructions for the bundle. This guarantees that the runtime call
is adjacent to the marker in the sequence, and that's information the
runtime can use to further optimize this.
This helps simplify some of the handling, in particular
BundledRetainClaimRVs, which no longer needs to know whether the bundle
is sufficient or not: it now always should be.
Note that this does not include an AutoUpgrade for the nullary bundles,
as they are only produced in ObjCContract as part of the obj/asm emission
pipeline, and are not expected to be in bitcode.
Differential Revision: https://reviews.llvm.org/D118214
Use the llvm flag `-pgo-function-entry-coverage` to create single byte "counters" to track functions coverage. This mode has significantly less size overhead in both code and data because
* We mark a function as "covered" with a store instead of an increment which generally requires fewer assembly instructions
* We use a single byte per function rather than 8 bytes per block
The trade off of course is that this mode only tells you if a function has been covered. This is useful, for example, to detect dead code.
When combined with debug info correlation [0] we are able to create an instrumented Clang binary that is only 150M (the vanilla Clang binary is 143M). That is an overhead of 7M (4.9%) compared to the default instrumentation (without value profiling) which has an overhead of 31M (21.7%).
[0] https://groups.google.com/g/llvm-dev/c/r03Z6JoN7d4
Reviewed By: kyulee
Differential Revision: https://reviews.llvm.org/D116180
This updates the Bug Life Cycle docs now that we've switched to GitHub
issues. The intent is to retain the same general process we used to
use for triaging bugs under Bugzilla, but with the facilities we have
available in GitHub.
This adds an option --show-tags to "memory read".
(lldb) memory read mte_buf mte_buf+32 -f "x" -s8 --show-tags
0x900fffff7ff8000: 0x0000000000000000 0x0000000000000000 (tag: 0x0)
0x900fffff7ff8010: 0x0000000000000000 0x0000000000000000 (tag: 0x1)
Tags are printed on the end of each line, if that
line has any tags associated with it. Meaning that
untagged memory output is unchanged.
Tags are printed based on the granule(s) of memory that
a line covers. So you may have lines with 1 tag, with many
tags, no tags or partially tagged lines.
In the case of partially tagged lines, untagged granules
will show "<no tag>" so that the ordering is obvious.
For example, a line that covers 2 granules where the first
is not tagged:
(lldb) memory read mte_buf-16 mte_buf+16 -l32 -f"x" --show-tags
0x900fffff7ff7ff0: 0x00000000 <...> (tags: <no tag> 0x0)
Untagged lines will just not have the "(tags: ..." at all.
Though they may be part of a larger output that does have
some tagged lines.
To do this I've extended DumpDataExtractor to also print
memory tags where it has a valid execution context and
is asked to print them.
There are no special alignment requirements, simply
use "memory read" as usual. All alignment is handled
in DumpDataExtractor.
We use MakeTaggedRanges to find all the tagged memory
in the current dump, then read all that into a MemoryTagMap.
The tag map is populated once in DumpDataExtractor and re-used
for each subsequently printed line (or recursive call of
DumpDataExtractor, which some formats do).
Reviewed By: omjavaid
Differential Revision: https://reviews.llvm.org/D107140
To avoid listing all the bit containers in the title and do not use the
specific number for the number of bit containers.
Differential Revision: https://reviews.llvm.org/D117849
In "Other Set-Like Container Options":
* Drops the references to C++ TR1 and SGI and hash_set.
* Drops the worry about portability (this was a problem with hash_set, but
std::unordered_set has worked portably since LLVM started depending
on C++11).
It is similar in "Other Map-Like Container Options" section.
Differential Revision: https://reviews.llvm.org/D117858
Summary:
Update the documentation for default code object version (from v3 to v4).
Reviewers:
kzhuravl
Differential Revision:
https://reviews.llvm.org/D117845
The behavior in Analysis (knownbits) implements poison semantics already,
and we expect the transforms (for example, in instcombine) derived from
those semantics, so this patch changes the LangRef and remaining code to
be consistent. This is one more step in removing "undef" from LLVM.
Without this, I think https://github.com/llvm/llvm-project/issues/53330
has a legitimate complaint because that report wants to allow subsequent
code to mask off bits, and that is allowed with undef values. The clang
builtins are not actually documented anywhere AFAICT, but we might want
to add that to remove more uncertainty.
Differential Revision: https://reviews.llvm.org/D117912
As suggested on the bug, to help (but not completely....) stop folded instructions crossing the inline asm barriers used for llvm-mca analysis, we should recommend tagging with memory captures/attributes.
Differential Revision: https://reviews.llvm.org/D117788
Add documentation around:
* Removing JITDylib from the session
* Add support for custom program representation
Reviewed By: lhames
Differential Revision: https://reviews.llvm.org/D116476
It is a known problem that we can't align the switch-based coroutine
frame if the alignment exceeds std::max_align_t (which is 16 usually).
We could solve the problem on the middle-end by dynamically transforming
or in the frontend by emitting aligned allocation function.
If we need to solve it in the frontend, the middle end need to offer an
intrinsic to tell the alignment at least. This patch tries to offer such
an intrinsic called llvm.coro.align.
Reviewed By: https://reviews.llvm.org/D117542
Differential revision: https://reviews.llvm.org/D117542
Confusion over this point came up in a couple of recent changes (D117180, e20b32ff3). Current tone of discussion seems to be that we think inaccessiblememonly was always legal on allocation functions, so this change takes the form of a clarification instead of a change.
Differential Revision: https://reviews.llvm.org/D117571
This patch fixes a case where the 'align' parameter attribute on the
pointer operands to llvm.vp.gather and llvm.vp.scatter was being dropped
during the conversion to the SelectionDAG. The default alignment equal
to the ABI type alignment of the vector type was kept. It also updates
the documentation to reflect the fact that the parameter attribute is
now properly supported.
The default alignment of these intrinsics was previously documented as
being equal to the ABI alignment of the *scalar* type, when in fact that
wasn't the case: the ABI alignment of the vector type was used instead.
This has also been fixed in this patch.
Reviewed By: simoll, craig.topper
Differential Revision: https://reviews.llvm.org/D114423
- Add current iteration to the context of a DWARF expression evaluation.
- Add DW_AT_LLVM_iterations attribute to specify the number of
iterations executing concurrently.
- Add DF_OP_LLVM_push_iteration to support optimizations that result in
multiple iterations executing concurrently.
- Add DW_OP_LLVM_overlay and DW_OP_LLVM_bit_overlay to support
expressing the location of arrays that are promoted to vector
registers in SIMD vectorized loops.
- Generally clarify the difference between SIMT and SIMD execution.
- Change the DW_AT_LLVM_active_lane attribute to take location
description expression so that a loclist can be used to express
different vales at different program locations.
Reviewed By: scott.linder
Differential Revision: https://reviews.llvm.org/D117572
Since 26c6a3e736, LLVM's inliner will "upgrade" the caller's stack protector
attribute based on the callee. This lead to surprising results with Clang's
no_stack_protector attribute added in 4fbf84c173 (D46300). Consider the
following code compiled with clang -fstack-protector-strong -Os
(https://godbolt.org/z/7s3rW7a1q).
extern void h(int* p);
inline __attribute__((always_inline)) int g() {
return 0;
}
int __attribute__((__no_stack_protector__)) f() {
int a[1];
h(a);
return g();
}
LLVM will inline g() into f(), and f() would get a stack protector, against the
users explicit wishes, potentially breaking the program e.g. if h() changes the
value of the stack cookie. That's a miscompile.
More recently, bc044a88ee (D91816) addressed this problem by preventing
inlining when the stack protector is disabled in the caller and enabled in the
callee or vice versa. However, the problem remained if the callee is marked
always_inline as in the example above. This affected users, see e.g.
http://crbug.com/1274129 and http://llvm.org/pr52886.
One way to fix this would be to prevent inlining also in the always_inline
case. Despite the name, always_inline does not guarantee inlining, so this
would be legal but potentially surprising to users.
However, I think the better fix is to not enable the stack protector in a
caller based on the callee. The motivation for the old behaviour is unclear, it
seems counter-intuitive, and causes real problems as we've seen.
This commit implements that fix, which means in the example above, g() gets
inlined into f() (also without always_inline), and f() is emitted without stack
protector. I think that matches most developers' expectations, and that's also
what GCC does.
Another effect of this change is that a no_stack_protector function can now be
inlined into a stack protected function, e.g. (https://godbolt.org/z/hafP6W856):
extern void h(int* p);
inline int __attribute__((__no_stack_protector__)) __attribute__((always_inline)) g() {
return 0;
}
int f() {
int a[1];
h(a);
return g();
}
I think that's fine. Such code would be unusual since no_stack_protector is
normally applied to a program entry point which sets up the stack canary. And
even if such code exists, inlining doesn't change the semantics: there is still
no stack cookie setup/check around entry/exit of the g() code region, but there
may be in the surrounding context, as there was before inlining. This also
matches GCC.
See also the discussion at https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94722
Differential revision: https://reviews.llvm.org/D116589
IR:
- globals (and functions, ifuncs, aliases) can have a partition
- catchret has a `to` before the label
- the sint/int types do not exist
- signext comes after the type
- a variable was missing its type
TableGen:
- The second value after a `#` concatenation is optional
See e.g. llvm/lib/Target/X86/X86InstrAVX512.td:L3351
- IncludeDirective and PreprocessorDirective were never referenced in
the grammar
- Add some missing ;
- Parent classes of multiclasses can have generic arguments.
Reuse the `ParentClassList` that is already used in other places.
MIR:
- liveins only allows physical registers, which start with a $
Differential Revision: https://reviews.llvm.org/D116674
llvm.vp.merge interprets the %evl operand differently than the other vp
intrinsics: all lanes at positions greater or equal than the %evl
operand are passed through from the second vector input. Otherwise it
behaves like llvm.vp.select.
Reviewed By: craig.topper
Differential Revision: https://reviews.llvm.org/D116725
memory-barrier instructions to providing targets and developers a convenient
way to explicitly declare which instructions are memory-barriers.
Differential Revision: https://reviews.llvm.org/D116779
We would like to nominate Andy Kaylor and Sergey Maslov to join the LLVM security group as a representative of Intel. Both are members of the Intel compiler team, and would like to register as vendor contacts. Intel packages and distributes LLVM-based toolchains as part of our compiler products. As such, we would like to be aware of any security vulnerability found in the compiler, and would like to contribute to the resolution of such issues.
Please let us know if anything is missing from the nomination.
Reviewed By: apilipenko, dim, george.burgess.iv, kristof.beyls, mattdr, nikhgupt, probinson, peter.smith, pietroalbini, steveklabnik
Differential Revision: https://reviews.llvm.org/D115657
Changpeng Fang